0000950170-23-041408 | 10-Q | XBRL Viewer

Print Document View Excel Document

Fair Value Measurement - Additional Information (Detail)	Jun. 30, 2023 USD ($)
Fair Value Disclosures [Abstract]
Fair value input transfer between levels	$ 0

Note Payable	6 Months Ended
Jun. 30, 2023
Debt Disclosure [Abstract]
Note Payable	8. Note Payable On November 2, 2021 (the “Closing Date”), the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (“SVB”) pursuant to which a term loan in an aggregate principal amount of up to $50,000 (the “Term Loan Facility”) was available to the Company in three tranches, subject to certain terms and conditions. The first tranche of $15,000 was advanced to the Company on the Closing Date. Subject to the terms and conditions of the Loan Agreement, the first tranche allowed the Company to borrow an additional $15,000 through October 31, 2023. Upon satisfaction of certain milestones, the second and third tranches were available under the Term Loan Facility which allowed the Company to borrow an additional amount up to $10,000 in each tranche through October 31, 2023. Additionally, the Company could seek to borrow up to an additional $15,000 at the sole discretion of the lender through the term of the Loan Agreement. The Loan Agreement provided for an October 1, 2026 maturity date (the “Maturity Date”). The Company was required to pay an end of term fee (“End of Term Charge”) equal to 9.00% of the aggregate principal amount of the Term Loan advances upon repayment. Advances under the Term Loan Facility bore interest at a rate equal to the greater of either (i) the Prime Rate (as reported in The Wall Street Journal) plus 4.85%, and (ii) 8.10%. The Company was obligated to make interest only payments through November 1, 2024. Following the interest only period, the Company was to repay the principal balance and interest of the advances in equal monthly installments through October 1, 2026. The Company could prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge (the “Prepayment Premium”) equal to: (a) 1.50% of amounts so prepaid, if such prepayment occurred during the first year following the Closing Date; (b) 1.00% of the amount so prepaid, if such prepayment occurred during the second year following the Closing Date, and (c) 0.00% of the amount so prepaid, if such prepayment occurred after the second year following the Closing Date. Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company was required to pay (in addition to any Prepayment Premium) an end of term charge of 9.0% of the aggregate funded amount under the Term Loan Facility. The Term Loan Facility was secured by substantially all of the Company’s assets, other than the Company’s intellectual property. The Company agreed to not pledge or secure its intellectual property to others. The End of Term Charge is recorded as a debt discount with an initial carrying balance of $1,350. During the year ended December 31, 2021 the Company recognized $103 of debt issuance costs related to legal expenses that has been included in the debt discount balance. The debt discount costs are being accreted to the principal amount of debt and being amortized from the date of issuance through the Maturity Date to interest expense using the effective-interest rate method. The effective interest rate of the outstanding debt under the Loan Agreement was approximately 16.29%. On June 9, 2023, upon the closing of the Asset Sale, all outstanding amounts due and owed, including principal, interest, and other charges, under the Term Loan Facility, dated as of November 2, 2021, by and among the Company, Silicon Valley Bank, a division of First-Citizens Bank & Trust and the other parties thereto, were repaid in full and the Term Loan Facility was terminated. Upon repayment, the obligations of the Company under the Term Loan Facility were satisfied in full, the Term Loan Facility and all related loan documents were terminated and all liens and security interests granted thereunder were released and terminated (excluding certain indemnification obligations that expressly survive termination of the Term Loan Facility). During the three months ended June 30, 2023 and 2022, the Company recognized $1,367 and $333 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. Of the $1,367 recognized during the three months ended June 30, 2023, $939 is related to the loss on the extinguishment of debt due to the write off of the debt discount balance. During the six months ended June 30, 2023 and 2022, the Company recognized $1,917 and $638 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. Of the $1,917 recognized during the six months ended June 30, 2023, $939 is related to the loss on the extinguishment of debt due to the write off of the debt discount balance.

Note Payable

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

Note Payable

8. Note Payable

On November 2, 2021 (the “Closing Date”), the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Silicon Valley Bank (“SVB”) pursuant to which a term loan in an aggregate principal amount of up to $50,000 (the “Term Loan Facility”) was available to the Company in three tranches, subject to certain terms and conditions. The first tranche of $15,000 was advanced to the Company on the Closing Date. Subject to the terms and conditions of the Loan Agreement, the first tranche allowed the Company to borrow an additional $15,000 through October 31, 2023. Upon satisfaction of certain milestones, the second and third tranches were available under the Term Loan Facility which allowed the Company to borrow an additional amount up to $10,000 in each tranche through October 31, 2023. Additionally, the Company could seek to borrow up to an additional $15,000 at the sole discretion of the lender through the term of the Loan Agreement. The Loan Agreement provided for an October 1, 2026 maturity date (the “Maturity Date”). The Company was required to pay an end of term fee (“End of Term Charge”) equal to 9.00% of the aggregate principal amount of the Term Loan advances upon repayment.

Advances under the Term Loan Facility bore interest at a rate equal to the greater of either (i) the Prime Rate (as reported in The Wall Street Journal) plus 4.85%, and (ii) 8.10%. The Company was obligated to make interest only payments through November 1, 2024. Following the interest only period, the Company was to repay the principal balance and interest of the advances in equal monthly installments through October 1, 2026.

The Company could prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge (the “Prepayment Premium”) equal to: (a) 1.50% of amounts so prepaid, if such prepayment occurred during the first year following the Closing Date; (b) 1.00% of the amount so prepaid, if such prepayment occurred during the second year following the Closing Date, and (c) 0.00% of the amount so prepaid, if such prepayment occurred after the second year following the Closing Date.

Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company was required to pay (in addition to any Prepayment Premium) an end of term charge of 9.0% of the aggregate funded amount under the Term Loan Facility.

The Term Loan Facility was secured by substantially all of the Company’s assets, other than the Company’s intellectual property. The Company agreed to not pledge or secure its intellectual property to others.

The End of Term Charge is recorded as a debt discount with an initial carrying balance of $1,350. During the year ended December 31, 2021 the Company recognized $103 of debt issuance costs related to legal expenses that has been included in the debt discount balance. The debt discount costs are being accreted to the principal amount of debt and being amortized from the date of issuance through the Maturity Date to interest expense using the effective-interest rate method. The effective interest rate of the outstanding debt under the Loan Agreement was approximately 16.29%.

On June 9, 2023, upon the closing of the Asset Sale, all outstanding amounts due and owed, including principal, interest, and other charges, under the Term Loan Facility, dated as of November 2, 2021, by and among the Company, Silicon Valley Bank, a division of First-Citizens Bank & Trust and the other parties thereto, were repaid in full and the Term Loan Facility was terminated. Upon repayment, the obligations of the Company under the Term Loan Facility were satisfied in full, the Term Loan Facility and all related loan documents were terminated and all liens and security interests granted thereunder were released and terminated (excluding certain indemnification obligations that expressly survive termination of the Term Loan Facility).

During the three months ended June 30, 2023 and 2022, the Company recognized $1,367 and $333 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. Of the $1,367 recognized during the three months ended June 30, 2023, $939 is related to the loss on the extinguishment of debt due to the write off of the debt discount balance. During the six months ended June 30, 2023 and 2022, the Company recognized $1,917 and $638 of interest expense related to the Loan Agreement which is reflected in other (expense) income, net on the consolidated statements of operations and comprehensive income (loss), respectively. Of the $1,917 recognized during the six months ended June 30, 2023, $939 is related to the loss on the extinguishment of debt due to the write off of the debt discount balance.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Nature of the Business	6 Months Ended
Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business AVROBIO, Inc. (the “Company” or “AVROBIO”) is a clinical-stage gene therapy company which has been focused on developing potentially curative ex vivo lentiviral gene therapies to treat rare diseases following a single dose treatment regimen. On July 12, 2023, following a comprehensive review of the Company’s business by its Board of Directors (the “Board”), the Company announced its intention to halt development of its programs and explore strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture. See Note 13 for further discussion. The Company is subject to risks and uncertainties including, should it resume development of its product candidates, risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Should the Company resume development of its product candidates, significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization, would be required. These efforts would require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, should the Company resume development of its product candidates, it is uncertain when, if ever, the Company would realize revenue from product sales. In accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. The Company has devoted substantially all of its efforts to research and development, business planning, acquiring operating assets, seeking protection for its technology and product candidates, and raising capital. Since inception, the Company has had recurring losses and has funded its operations through sales of preferred stock and common stock, a term loan facility and the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. As of June 30, 2023, the Company had an accumulated deficit of $446,913. The Company expects that its cash and cash equivalents of $124,689 as of June 30, 2023 will be sufficient to fund current planned operations and capital expenditure requirements for at least the next twelve months from the filing date of this Quarterly Report on Form 10-Q with the Securities and Exchange Commission (“SEC”). However, the future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurance that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all. On May 19, 2023, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Novartis Pharma AG and Novartis Pharmaceuticals Corporation (collectively, “Novartis”), providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. The aggregate consideration to the Company consisted of a cash payment of $87,500 upon closing of the transaction. The Company completed the Asset Sale (defined below) on June 9, 2023 and recognized $83,736 as a gain on asset sale, net of $3,764 transaction costs, in the condensed consolidated statement of operations and comprehensive income (loss) for the three and six months ended June 30, 2023. See Note 3 for further discussion.

Nature of the Business

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of the Business

1. Nature of the Business

AVROBIO, Inc. (the “Company” or “AVROBIO”) is a clinical-stage gene therapy company which has been focused on developing potentially curative ex vivo lentiviral gene therapies to treat rare diseases following a single dose treatment regimen.

On July 12, 2023, following a comprehensive review of the Company’s business by its Board of Directors (the “Board”), the Company announced its intention to halt development of its programs and explore strategic alternatives focused on maximizing stockholder value, which may include, but are not limited to, an acquisition, a merger, business combination or divestiture. See Note 13 for further discussion.

The Company is subject to risks and uncertainties including, should it resume development of its product candidates, risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Should the Company resume development of its product candidates, significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization, would be required. These efforts would require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, should the Company resume development of its product candidates, it is uncertain when, if ever, the Company would realize revenue from product sales.

In accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the consolidated financial statements are issued.

The Company has devoted substantially all of its efforts to research and development, business planning, acquiring operating assets, seeking protection for its technology and product candidates, and raising capital. Since inception, the Company has had recurring losses and has funded its operations through sales of preferred stock and common stock, a term loan facility and the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. As of June 30, 2023, the Company had an accumulated deficit of $446,913. The Company expects that its cash and cash equivalents of $124,689 as of June 30, 2023 will be sufficient to fund current planned operations and capital expenditure requirements for at least the next twelve months from the filing date of this Quarterly Report on Form 10-Q with the Securities and Exchange Commission (“SEC”). However, the future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurance that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all.

On May 19, 2023, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Novartis Pharma AG and Novartis Pharmaceuticals Corporation (collectively, “Novartis”), providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. The aggregate consideration to the Company consisted of a cash payment of $87,500 upon closing of the transaction. The Company completed the Asset Sale (defined below) on June 9, 2023 and recognized $83,736 as a gain on asset sale, net of $3,764 transaction costs, in the condensed consolidated statement of operations and comprehensive income (loss) for the three and six months ended June 30, 2023. See Note 3 for further discussion.

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail) - shares	Jun. 30, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	18,855,320	19,259,640
Employee Stock Option [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	7,569,190	9,423,271
Restricted Stock Units [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	1,673,025	940,392
2018 Stock Option and Incentive Plan [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	5,519,799	5,005,295
2018 Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	1,445,752	1,467,026
2019 Inducement Plan [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	947,554	786,656
2020 Inducement Plan [Member]
Class Of Stock [Line Items]
Total shares of authorized common stock reserved for future issuance	1,700,000	1,637,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483014/272-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 272
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482987/272-10-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

+ Details

Supplemental Balance Sheet Information - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Supplemental Balance Sheet Information Disclosures [Abstract]
Prepaid research and development expenses	$ 2,725	$ 4,509
Tax incentive refund	270	269
Prepaid insurance	32	999
Prepaid compensation benefits	52	327
Other current assets	792	1,008
Prepaid expenses and other current assets	$ 3,871	$ 7,112

Leases - Summary of effective lease cost comprehensive income loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
Leases [Abstract]
Operating lease costs	$ 682	$ 1,353
Sublease income	(23)	(46)
Total lease costs	$ 659	$ 1,307

Stock-Based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

10. Stock-based Compensation

Stock Option Valuation

The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis:


	Six Months Ended June 30,
	2023			2022
Expected option life (years)		6.00			5.96
Risk-free interest rate		3.82	%		1.80	%
Expected volatility		83.36	%		80.22	%
Expected dividend yield		—	%		—	%

The following table summarizes the Company’s stock option activity for the six months ended June 30, 2023:


	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2022		9,423,271		$	7.26		8.14	$	22
Granted		123,501		$	1.09
Exercised		(116,586	)	$	0.61
Cancelled or forfeited		(1,860,996	)	$	5.66
Outstanding as of June 30, 2023		7,569,190		$	7.65		5.44	$	233
Exercisable as of June 30, 2023		4,180,445		$	10.79		4.29	$	7

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the underlying stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the estimated fair value of the Company’s common stock.

The aggregate intrinsic value of options exercised during the six months ended June 30, 2023 was $39. No options were exercised during the six months ended June 30, 2022.

The weighted-average grant-date fair value of the Company’s stock options granted during the six months ended June 30, 2023 and 2022 was $0.79 and $1.23, respectively.

Restricted Stock Units

The following table summarizes the Company’s restricted common stock units for the six months ended June 30, 2023:


	Number of Shares			Weighted- Average Grant Date Fair Value
Issued and unvested as of December 31, 2022		940,392		$	3.62
Granted		1,478,117		$	1.69
Vested		(253,460	)	$	5.47
Forfeited, cancelled or expired		(492,024	)	$	1.71
Issued and unvested as of June 30, 2023		1,673,025		$	2.19

The total fair value of restricted stock units vested during the six months ended June 30, 2023 and 2022 was $1,386 and $4, respectively.

Stock-Based Compensation

Stock-based compensation expense was allocated as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	669	$	783	$	1,291	$	1,721
General and administrative		865		2,451		2,773		4,890
Total stock-based compensation expense	$	1,534	$	3,234	$	4,064	$	6,611

As of June 30, 2023, total unrecognized compensation cost related to the unvested stock-based awards was $11,488, which is expected to be recognized over a weighted-average period of 2.21 years.

Supplemental Balance Sheet Information (Tables)

6 Months Ended

Jun. 30, 2023

Balance Sheet Related Disclosures [Abstract]

Summary of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:


	June 30, 2023		December 31, 2022
Prepaid research and development expenses	$	2,725	$	4,509
Tax incentive refund		270		269
Prepaid insurance		32		999
Prepaid compensation benefits		52		327
Other current assets		792		1,008
Prepaid expenses and other current assets	$	3,871	$	7,112

Summary of Property and Equipment, Net

Property and equipment, net consisted of the following:


	June 30, 2023			December 31, 2022
Laboratory and office equipment	$	5,973		$	5,967
Leasehold improvements		629			629
Computer equipment		104			102
		6,706			6,698
Less: Accumulated depreciation and amortization		(4,421	)		(3,804	)
Property and equipment, net	$	2,285		$	2,894

Summary of Restricted Cash

As of June 30, 2023 and December 31, 2022, the Company had restricted cash as presented in the table below, which consists of cash used to secure letters of credit for the benefit of the landlord in connection with the Company’s lease agreements. The cash will be restricted until the termination or modification of the lease arrangement.


	June 30, 2023		December 31, 2022
Restricted cash	$	283	$	283
Restricted cash, net of current portion		400		—

Summary of Accrued Expenses

Accrued expenses and other current liabilities consisted of the following:


	June 30, 2023		December 31, 2022
Research and development expenses	$	4,271	$	6,122
Compensation and benefit costs		3,693		4,175
Consulting and professional fees		375		1,224
Other liabilities		4		211
Accrued expenses and other current liabilities	$	8,343	$	11,732

Supplemental Balance Sheet Information

6 Months Ended

Jun. 30, 2023

Balance Sheet Related Disclosures [Abstract]

Supplemental Balance Sheet Information

5. Supplemental Balance Sheet Information

Prepaid expenses and other current assets

Prepaid expenses and other current assets consisted of the following:


	June 30, 2023		December 31, 2022
Prepaid research and development expenses	$	2,725	$	4,509
Tax incentive refund		270		269
Prepaid insurance		32		999
Prepaid compensation benefits		52		327
Other current assets		792		1,008
Prepaid expenses and other current assets	$	3,871	$	7,112

Property and equipment, net

Property and equipment, net consisted of the following:


	June 30, 2023			December 31, 2022
Laboratory and office equipment	$	5,973		$	5,967
Leasehold improvements		629			629
Computer equipment		104			102
		6,706			6,698
Less: Accumulated depreciation and amortization		(4,421	)		(3,804	)
Property and equipment, net	$	2,285		$	2,894

Depreciation and amortization expense was $289 and $354, respectively, for the three months ended June 30, 2023 and 2022. Depreciation and amortization expense was $617 and $753, respectively, for the six months ended June 30, 2023 and 2022.

Restricted cash


	June 30, 2023		December 31, 2022
Restricted cash	$	283	$	283
Restricted cash, net of current portion		400		—

Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following:


	June 30, 2023		December 31, 2022
Research and development expenses	$	4,271	$	6,122
Compensation and benefit costs		3,693		4,175
Consulting and professional fees		375		1,224
Other liabilities		4		211
Accrued expenses and other current liabilities	$	8,343	$	11,732

Net Loss Per Share - Schedule of Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	8,114,210	8,913,316	8,606,761	8,913,316
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	1,711,124	893,259	1,570,009	893,259

Stock-Based Compensation - Summary of Restricted Common Stock Units (Detail) - Restricted Stock Units [Member]	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Issued and unvested beginning balance \| shares	940,392
Number of shares, Granted \| shares	1,478,117
Number of shares, Vested \| shares	(253,460)
Number of shares, Forfeited, cancelled or expired \| shares	(492,024)
Number of shares, Issued and unvested ending balance \| shares	1,673,025
Weighted average grant date fair value, Issued and unvested, beginning balance \| $ / shares	$ 3.62
Weighted average grant date fair value, Granted \| $ / shares	1.69
Weighted average grant date fair value, Vested \| $ / shares	5.47
Weighted average grant date fair value, Forfeited, cancelled or expired \| $ / shares	1.71
Weighted average grant date fair value, Issued and unvested, ending balance \| $ / shares	$ 2.19

Fair Value Measurement

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurement

4. Fair Value Measurement

The following table presents information about the Company’s financial assets measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of June 30, 2023 and December 31, 2022:


	Fair Value Measurements as of June 30, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	123,363	$	—	$	—	$	123,363
	$	123,363	$	—	$	—	$	123,363


	Fair Value Measurements as of December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	91,095	$	—	$	—	$	91,095
	$	91,095	$	—	$	—	$	91,095

The fair value of cash equivalents was determined through quoted prices by third-party pricing services.

During the six months ended June 30, 2023, there were no transfers between levels.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

License Agreements - Additional Information (Detail) £ in Thousands, $ in Thousands						1 Months Ended	3 Months Ended				6 Months Ended			12 Months Ended
	Jun. 09, 2023 USD ($)	Sep. 30, 2020 USD ($)	Oct. 02, 2017 USD ($)	Jan. 27, 2016 CAD ($) shares	Jan. 27, 2016 USD ($)	Aug. 31, 2017 USD ($) shares	Jun. 30, 2023 USD ($) shares	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2023 GBP (£) shares	Jun. 30, 2023 USD ($) shares	Jun. 30, 2022 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)	May 19, 2023 USD ($)	Dec. 31, 2022 shares	Nov. 17, 2016 USD ($)
License Agreement [Line Items]
Collaborative agreement expenses							$ 0		$ 417,000			$ 1,610,000	$ 1,380,000
Common stock, issued \| shares							44,308,000				44,308,000	44,308,000					43,916,000
Research and development							$ 11,148,000		18,877,000			$ 28,481,000	38,130,000
Cash payment of closing the transaction																$ 87,500,000
Gain loss on recognize assets sales	$ 83,736,000						83,736,000					$ 3,764,000
Sale of Cystinosis Program [Member]
License Agreement [Line Items]
Cash payment of closing the transaction																$ 87,500,000
University of Manchester Agreement [Member] \| MPSII License Agreement [Member]
License Agreement [Line Items]
Upfront license fee														$ 8,000,000
Milestone payments payable		$ 80,000,000
Milestone payment paid		2,000,000
Milestone payment due		$ 4,000,000
Agreement Expiration Period											15 years	15 years
Agreement Expiration Description											upon the later of 15 years from the effective date or the expiration of the last valid claim of the licensed patent	upon the later of 15 years from the effective date or the expiration of the last valid claim of the licensed patent
Research and development expense \| £											£ 9,900
UHN Agreement [Member]
License Agreement [Line Items]
Research and development expense							0		0			$ 34,000	24,000
Milestone fees							0		0			0	0
UHN Agreement [Member] \| Fabry License Agreement [Member]
License Agreement [Line Items]
Upfront license fee				$ 75
Milestone payments payable				2,450
Option fee				20
UHN Agreement [Member] \| Interleukin 12 License Agreement [Member]
License Agreement [Line Items]
Upfront license fee				264
Milestone payments payable				19,275
Milestone fees							0		0			0	0
Annual maintenance fees				$ 50
Common stock, issued \| shares				1,161,665
Fair value of shares issued					$ 480,000
Payments upon closing of an initial public offering					$ 2,000,000										$ 2,000,000
Research and development								$ 0	39,000			37,000	39,000
BioMarin Pharmaceutical Inc [Member]
License Agreement [Line Items]
Upfront license fee						$ 500,000
Preferred stock issued \| shares						233,765
Milestone payments												13,000,000
Expenses related to license							0		0			0	0
GenStem Therapeutics Inc [Member]
License Agreement [Line Items]
Upfront license fee			$ 1,000,000
Milestone payments payable			$ 16,000,000
Expenses related to license							$ 0		$ 0			0	$ 0
Lund University Rights Holders Agreement [Member]
License Agreement [Line Items]
Milestone payments payable																		$ 550,000
Expenses related to license										$ 0		$ 0

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying condensed consolidated financial statements (the “unaudited condensed consolidated financial statements”) have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements as of and for the year ended December 31, 2022, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2023, and the results of its operations for the three and six months ended June 30, 2023 and 2022, its statements of stockholders’ equity for the three and six months ended June 30, 2023 and 2022 and its statement of cash flows for the six months ended June 30, 2023 and 2022.

The results for the three and six months ended June 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2022, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 23, 2023.

The unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the unaudited condensed consolidated financial statements. As of June 30, 2023, there have been no changes to the Company’s significant accounting policies as described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022.

Segment Information

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer (“CEO”). The Company and the CEO view the Company’s operations and manage its business as one operating segment. All material long-lived assets of the Company reside in the United States.

Use of Estimates

The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires that the Company make estimates and judgments that may affect the reported amounts of assets, liabilities and expenses and the related disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates. Changes in estimates are reflected in reported results in the period in which they become known.

Significant estimates relied upon in preparing the unaudited condensed consolidated financial statements include the determination of the fair value of share-based awards issued and the estimation of accrued research and development expenses.

Stock-based Compensation

For stock-based awards issued to employees and members of the Company’s Board for their services on the Board, the Company measures the estimated fair value of the stock-based award on the date of grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The Company issues stock-based awards with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company has not issued any stock-based awards with performance- or market-based vesting conditions. The Company accounts for forfeitures as they occur.

Prior to the adoption of Accounting Standards Update (“ASU”) No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, the measurement date for non-employee awards was generally the date the services are completed, resulting in financial reporting period adjustments to stock-based compensation during the vesting terms for changes in the fair value of the awards. After adoption of ASU 2018-07, the measurement date for non-employee awards is the later of the adoption date of ASU 2018-07, or the date of grant, without change in the fair value of the award. For stock-based awards granted to nonemployees subject to graded vesting that only contain service conditions, the Company has elected to recognize stock-based compensation expense using the straight-line recognition method.

The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive income (loss) in the same manner in which the award recipient’s cash compensation costs are classified.

Emerging Growth Company Status

The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of its IPO or such earlier time that it is no longer an “emerging growth company.”

Subsequent Event Considerations

The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.

Recently Adopted Accounting Pronouncements

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, or ASU 2016-13. ASU 2016-13 requires that credit losses be reported as an allowance using an expected losses model, representing the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities with unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations.

In November 2019, the FASB issued ASU 2019-11, “Codification Improvements to Topic 326, Financial Instruments – Credit Losses,” or ASU 2019-11. ASU 2019-11 is an accounting pronouncement that amends ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendments update guidance on reporting credit losses for financial assets. These amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations.

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net income (loss)	$ 42,519	$ (57,887)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on asset sale	(83,736)
Stock-based compensation expense	4,064	6,611
Depreciation and amortization expense	617	753
Non-cash interest expense	1,074	159
Loss on disposal of property and equipment		9
Deferred rent expense		(97)
Non-cash lease expense	1,182
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	3,241	(94)
Other assets		21
Accounts payable	687	(3,458)
Current and non-current operating lease liabilities	(1,195)
Accrued expenses and other current liabilities	(3,389)	(3,137)
Net cash used in operating activities	(34,936)	(57,120)
Cash flows from investing activities:
Proceeds from asset sale, net	83,736	0
Purchases of property and equipment	(8)	(181)
Net cash used in investing activities	83,728	(181)
Cash flows from financing activities:
Repayment of note payable, including end of term charge	(16,350)	0
Proceeds from exercise of stock options	71
Proceeds from issuance of ESPP shares	13	143
Net cash provided by (used in) financing activities	(16,266)	143
Net increase (decrease) in cash, cash equivalents and restricted cash	32,526	(57,158)
Cash, cash equivalents and restricted cash at beginning of period	92,846	190,059
Cash, cash equivalents and restricted cash, end of period	125,372	132,901
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	0	73
Interest paid	831	628
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets:
Cash and cash equivalents, end of period	124,689	132,409
Restricted cash	683	492
Cash, cash equivalents and restricted cash, end of period	$ 125,372	$ 132,901

Subsequent Events (Additional Information) (Details) - USD ($) $ in Millions		3 Months Ended
	Jul. 12, 2023	Dec. 31, 2023
Board Of Directors [Member]
Subsequent Event [Line Items]
Company workforce reduction	50.00%
Subsequent Event [Member]
Subsequent Event [Line Items]
Subsequent event, date	Jul. 06, 2023
Severance and termination related costs		$ 2.8

Related Party Transactions

6 Months Ended

Jun. 30, 2023

Related Party Transactions

12. Related Party Transactions

UHN

For the three months ended June 30, 2023, the Company did not recognize expenses for research and development expense related to the license agreements with UHN. For the three months ended June 30, 2022, the Company recognized $39 of research and development expense related to the license agreements with UHN. For the six months ended June 30, 2023 and 2022, the Company recognized $71 and $63, respectively, of research and development expense related to the license agreements with UHN. Refer to Note 3 “License Agreements” for additional information regarding the UHN license agreements.

Others

For the three months ended June 30, 2023 and 2022, the Company recorded expenses of $102 and $792, respectively, related to a sublease to rent lab space, provided by an entity affiliated with a member of the Company’s Board. For the six months ended June 30, 2023 and 2022, the Company recorded expenses of $754 and $1,586, respectively, related to a sublease to rent lab space, provided by an entity affiliated with a member of the Company’s Board.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Note Payable - Additional Information (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Nov. 02, 2021 USD ($) Tranche	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Disclosure [Line Items]
Interest expense recognized		$ 1,367	$ 333	$ 1,917	$ 638
Loan Agreement [Member]
Debt Disclosure [Line Items]
Gain (Loss) on Extinguishment of Debt, before Debt Issuance Cost Writeoff		1,367		1,917
Deferred Debt Issuance Cost, Writeoff		$ 939		$ 939
Loan Agreement [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Loan, interest rate	16.29%
Debt discount	$ 1,350
Loan Agreement [Member] \| Silicon Valley Bank [Member] \| Legal Expenses [Member]
Debt Disclosure [Line Items]
Debt Issuance Costs, Net						$ 103
Term Loan Facility [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Loan maturity date	Oct. 01, 2026
End of term charge as percentage on principal amount	9.00%
Loan, interest rate	8.10%
Term Loan Facility [Member] \| Silicon Valley Bank [Member] \| Prime Rate [Member]
Debt Disclosure [Line Items]
Loan, interest rate	4.85%
Term Loan Facility [Member] \| Loan Agreement [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Borrowing amount	$ 50,000
Debt instrument number of tranches \| Tranche	3
Proceeds from loan agreement	$ 15,000
Additional borrowing amount	15,000
Line of credit facility additional discretionary	$ 15,000
Loan maturity date	Oct. 01, 2026
End of term charge as percentage on principal amount	9.00%
Term Loan Facility [Member] \| Loan Agreement [Member] \| Silicon Valley Bank [Member] \| Regulatory Milestone [Member]
Debt Disclosure [Line Items]
Additional borrowing amount	$ 10,000
Term Loan Prepayment During First Year [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Line of credit facility prepayment of premium percentage	1.50%
Term Loan Prepayment During Second Year [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Line of credit facility prepayment of premium percentage	1.00%
Term Loan Prepayment After Second Year [Member] \| Silicon Valley Bank [Member]
Debt Disclosure [Line Items]
Line of credit facility prepayment of premium percentage	0.00%

Leases (Tables)

6 Months Ended

Jun. 30, 2023

Leases [Abstract]

Schedule of effective lease cost comprehensive income loss

The following table summarizes the effect of lease costs in the Company’s consolidated statement of operations and comprehensive income (loss):


	Three Months Ended June 30,			Six Months Ended June 30,
	2023			2023
Operating lease costs	$	682		$	1,353
Sublease income		(23	)		(46	)
Total lease costs	$	659		$	1,307

Schedule of Future Minimum Payments of Operating Lease Liabilities

As of June 30, 2023, future minimum payments of operating lease liabilities are as follows (in thousands):


	June 30, 2023
2023	$	1,414
2024		1,037
2025		70
2026		—
2027		—
Thereafter		—
Total lease payments	$	2,521
Less: interest		(155	)
Plus: FX gain/loss		18
Present value of lease liabilities	$	2,384

Leases

6 Months Ended

Jun. 30, 2023

Leases [Abstract]

Leases

6. Leases

On August 31, 2018, the Company entered into a sublease agreement for lab space located in Cambridge Massachusetts, United States, which was set to expire in October 2020. On June 9, 2020, the Company amended the terms of the sublease, which was set to expire in April 2022. Effective January 1, 2022, the Company amended the terms of the sublease, to extend the term through April 2023. In July 2022, the company moved its corporate headquarters to its subleased space in this location. Effective January 24, 2023, the Company amended the terms of the sublease, which is now set to expire in April 2024. The annual lease payments are subject to a 5% increase each year. In accordance with the lease agreement, the Company is required to maintain a security deposit of $283, which was recorded in restricted cash as of June 30, 2023 and December 31, 2022.

On June 1, 2020, the Company entered into a lease agreement for office space located in Toronto, Ontario, Canada, which is set to expire in June 2025. The annual lease payments are fixed for years 1 and 2, and then subject to a 6.67% increase for years 3 through 5. In accordance with the lease agreement, the Company is required to maintain a security deposit of CAD$27, which was recorded in other long-term assets as of June 30, 2023 and December 31, 2022. In October 2022, the Company entered into a sublease agreement to sublease this space. The term of the sublease agreement commenced on October 1, 2022 and expires on June 29, 2025.

The following table summarizes the effect of lease costs in the Company’s consolidated statement of operations and comprehensive income (loss):


	Three Months Ended June 30,			Six Months Ended June 30,
	2023			2023
Operating lease costs	$	682		$	1,353
Sublease income		(23	)		(46	)
Total lease costs	$	659		$	1,307

During the three months ended June 30, 2023 and 2022, the Company made cash payments for operating leases of $694 and $831, respectively. During the six months ended June 30, 2023 and 2022, the Company made cash payments for operating leases of $1,381 and $1,661, respectively.

As of June 30, 2023, future minimum payments of operating lease liabilities are as follows (in thousands):


	June 30, 2023
2023	$	1,414
2024		1,037
2025		70
2026		—
2027		—
Thereafter		—
Total lease payments	$	2,521
Less: interest		(155	)
Plus: FX gain/loss		18
Present value of lease liabilities	$	2,384

As of June 30, 2023, the weighted average remaining lease term was 1.0 year and the weighted average incremental borrowing rate used to determine the operating lease liability was 15.59%. As of June 30, 2022, the weighted average remaining lease term was 1.1 years and the weighted average incremental borrowing rate used to determine the operating lease liability was 10.50%.

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating expenses:
Research and development	$ 11,148	$ 18,877	$ 28,481	$ 38,130
General and administrative	4,581	8,897	12,468	19,062
Total operating expenses	15,729	27,774	40,949	57,192
Gain on asset sale	83,736	0	83,736	0
Gain (loss) from operations	68,007	(27,774)	42,787	(57,192)
Other (expense) income:
Interest expense, net	(495)	(285)	(247)	(655)
Other (expense) income, net	(36)	5	(21)	(40)
Total other expense, net	(531)	(280)	(268)	(695)
Net loss and comprehensive loss	$ 67,476	$ (28,054)	$ 42,519	$ (57,887)
Net income (loss) per share applicable to common stockholders basic	$ 1.53	$ (0.64)	$ 0.96	$ (1.32)
Net income (loss) per share applicable to common stockholders diluted	$ 1.52	$ (0.64)	$ 0.96	$ (1.32)
Weighted-average common shares outstanding basic	44,134,436	43,696,000	44,085,977	43,695,769
Weighted-average number of common shares outstanding - diluted	44,280,606	43,696,000	44,271,016	43,695,769

Stockholders' Equity - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Equity [Abstract]
Common stock, authorized	150,000,000	150,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Undesignated preferred stock	10,000,000	10,000,000
Undesignated shares of preferred stock outstanding	0	0
Cash dividends	$ 0

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Summary of Common Stock Reserved for Future Issuance

As of June 30, 2023 and December 31, 2022, the Company has reserved the following shares of common stock for future issuance:


	June 30, 2023		December 31, 2022
Shares reserved for exercise of outstanding stock options		7,569,190		9,423,271
Shares reserved for vesting of restricted stock units		1,673,025		940,392
Shares reserved for issuance under the 2018 Stock Option and Grant Plan		5,519,799		5,005,295
Shares reserved for issuance under the 2018 Employee Stock Purchase Plan		1,445,752		1,467,026
Shares reserved for issuance under the 2019 Inducement Plan		947,554		786,656
Shares reserved for issuance under the 2020 Inducement Plan		1,700,000		1,637,000
Total shares of authorized common stock reserved for future issuance		18,855,320		19,259,640

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-3

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-4

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-5

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481142/505-10-45-2

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-10

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-8

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480244/480-10-S99-1

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-6

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-7

+ Details

Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 1,534	$ 3,234	$ 4,064	$ 6,611
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	669	783	1,291	1,721
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 865	$ 2,451	$ 2,773	$ 4,890

Leases (Additional Information) (Details) $ in Thousands, $ in Thousands					3 Months Ended		6 Months Ended
	Jan. 01, 2022	Jun. 09, 2020	Jun. 01, 2020	Aug. 31, 2018	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 CAD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 CAD ($)	Dec. 31, 2022 USD ($)
Lessee, Lease, Description [Line Items]
Percentage of annual increase in rent	5.00%		6.67%
Lease Expiration Month And Year	2023-04	2022-04	2025-06	2020-10
Annual Lease Payments Description							The annual lease payments are fixed for years 1 and 2, and then subject to a 6.67% increase for years 3 through 5
Lease Expiration Date			Jun. 29, 2025
Operating leases and Rent expenses					$ 694	$ 831	$ 1,381	$ 1,661
Weighted average remaining lease						1 year 1 month 6 days		1 year 1 month 6 days	1 year	1 year
Weighted average incremental borrowing rate						10.50%		10.50%	15.59%	15.59%
Restricted Cash [Member]
Lessee, Lease, Description [Line Items]
Security Deposit										$ 283		$ 283
Other Noncurrent Assets [Member]
Lessee, Lease, Description [Line Items]
Security Deposit									$ 27		$ 27

Leases - Summary of Future Minimum Payments of Operating Lease Liabilities (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Leases [Abstract]
2023	$ 1,414
2024	1,037
2025	70
2026	0
2027	0
Thereafter	0
Total lease payments	2,521
Less: interest	(155)
Plus: FX gain/loss	18
Present value of lease liabilities	$ 2,384

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value on Recurring Basis [Member] - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets Fair Value Disclosure
Assets Fair Value Disclosure	$ 123,363	$ 91,095
Money Market Funds [Member] \| Cash Equivalents [Member]
Assets Fair Value Disclosure
Assets Fair Value Disclosure	123,363	91,095
Level 1 [Member]
Assets Fair Value Disclosure
Assets Fair Value Disclosure	123,363	91,095
Level 1 [Member] \| Money Market Funds [Member] \| Cash Equivalents [Member]
Assets Fair Value Disclosure
Assets Fair Value Disclosure	$ 123,363	$ 91,095

Nature of the Business - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jun. 09, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	May 19, 2023	Dec. 31, 2022
Net Income (Loss)		$ 67,476	$ (28,054)	$ 42,519	$ (57,887)
Accumulated deficit		(446,913)		(446,913)			$ (489,432)
Cash payment of closing the transaction						$ 87,500
Cash and cash equivalents		124,689	$ 132,409	124,689	$ 132,409		$ 92,563
Gain loss on recognize assets sales	$ 83,736	$ 83,736		$ 3,764

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482765/220-10-50-6

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-8

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-9

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480167/946-830-55-10

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483581/946-220-45-7

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(9))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 32: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483499/205-20-50-7

Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Supplemental Balance Sheet Information - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Supplemental Balance Sheet Information Disclosures [Abstract]
Depreciation and amortization expense	$ 289	$ 354	$ 617	$ 753

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 124,689	$ 92,563
Restricted cash	283	283
Prepaid expenses and other current assets	3,871	7,112
Total current assets	128,843	99,958
Operating lease assets	2,267	1,057
Property and equipment, net	2,285	2,894
Restricted cash, net of current portion	400	0
Other assets	40	40
Total assets	133,835	103,949
Current liabilities:
Accounts payable	1,071	384
Accrued expenses and other current liabilities	8,343	11,732
Operating lease liabilities	2,250	999
Total current liabilities	11,664	13,115
Note payable, net of discount	0	15,276
Operating lease liabilities, net of current portion	134	188
Total liabilities	11,798	28,579
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock, $0.0001 par value; 150,000 shares authorized; 44,308 and 43,916 shares issued and outstanding as of June 30, 2023 and December 31, 2022, respectively	4	4
Additional paid-in capital	568,946	564,798
Accumulated deficit	(446,913)	(489,432)
Total stockholders’ equity	122,037	75,370
Total liabilities and stockholders’ equity	$ 133,835	$ 103,949

Commitments and Contingencies

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

7. Commitments and Contingencies

Legal Proceedings

The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the six months ended June 30, 2023 and 2022 and to the best of the Company’s knowledge, no material legal proceedings are currently pending or threatened.

Other

The Company is also party to various agreements, principally relating to licensed technology, that require future payments relating to milestones not met at June 30, 2023 and December 31, 2022, or royalties on future sales. No milestone or royalty payments under these agreements are expected to be payable in the immediate future, except as disclosed in Note 3 “License Agreements.”

The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the agreements, the Company agrees to indemnify, hold harmless, and to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company’s business partners, in connection with any U.S. patent or any copyright or other intellectual property infringement claim by any third-party with respect to the Company’s products. Further, the Company indemnifies its directors and officers who are, or were, serving at the Company’s request in such capacities. The Company’s maximum exposure under these arrangements is unknown as of June 30, 2023. The Company does not anticipate recognizing any significant losses relating to these arrangements. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements.

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transaction [Line Items]
Research and development expense	$ 11,148	$ 18,877	$ 28,481	$ 38,130
Company Recorded Expenses	682		1,353
License Agreement [Member]
Related Party Transaction [Line Items]
Research and development expense		39	71	63
Sub-lease Agreement [Member] \| Officers and Board Members [Member]
Related Party Transaction [Line Items]
Company Recorded Expenses	$ 102	$ 792	$ 754	$ 1,586

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements (the “unaudited condensed consolidated financial statements”) have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements as of and for the year ended December 31, 2022, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of June 30, 2023, and the results of its operations for the three and six months ended June 30, 2023 and 2022, its statements of stockholders’ equity for the three and six months ended June 30, 2023 and 2022 and its statement of cash flows for the six months ended June 30, 2023 and 2022. The results for the three and six months ended June 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2022, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2022, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 23, 2023. The unaudited condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the unaudited condensed consolidated financial statements. As of June 30, 2023, there have been no changes to the Company’s significant accounting policies as described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022.
Segment Information	Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company’s chief operating decision maker is the chief executive officer (“CEO”). The Company and the CEO view the Company’s operations and manage its business as one operating segment. All material long-lived assets of the Company reside in the United States.
Use of Estimates	Use of Estimates The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires that the Company make estimates and judgments that may affect the reported amounts of assets, liabilities and expenses and the related disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates. Changes in estimates are reflected in reported results in the period in which they become known. Significant estimates relied upon in preparing the unaudited condensed consolidated financial statements include the determination of the fair value of share-based awards issued and the estimation of accrued research and development expenses.
Stock-Based Compensation	Stock-based Compensation For stock-based awards issued to employees and members of the Company’s Board for their services on the Board, the Company measures the estimated fair value of the stock-based award on the date of grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The Company issues stock-based awards with only service-based vesting conditions and records the expense for these awards using the straight-line method. The Company has not issued any stock-based awards with performance- or market-based vesting conditions. The Company accounts for forfeitures as they occur. Prior to the adoption of Accounting Standards Update (“ASU”) No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, the measurement date for non-employee awards was generally the date the services are completed, resulting in financial reporting period adjustments to stock-based compensation during the vesting terms for changes in the fair value of the awards. After adoption of ASU 2018-07, the measurement date for non-employee awards is the later of the adoption date of ASU 2018-07, or the date of grant, without change in the fair value of the award. For stock-based awards granted to nonemployees subject to graded vesting that only contain service conditions, the Company has elected to recognize stock-based compensation expense using the straight-line recognition method. The Company classifies stock-based compensation expense in its consolidated statements of operations and comprehensive income (loss) in the same manner in which the award recipient’s cash compensation costs are classified.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of its IPO or such earlier time that it is no longer an “emerging growth company.”
Subsequent Event Considerations	Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.
Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, or ASU 2016-13. ASU 2016-13 requires that credit losses be reported as an allowance using an expected losses model, representing the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities with unrealized losses, this standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations. In November 2019, the FASB issued ASU 2019-11, “Codification Improvements to Topic 326, Financial Instruments – Credit Losses,” or ASU 2019-11. ASU 2019-11 is an accounting pronouncement that amends ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendments update guidance on reporting credit losses for financial assets. These amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. On January 1, 2023 the Company adopted this standard, which had no impact on its financial position or results of operations.

- Definition

Disclosure of accounting policy for segment reporting.

+ References + Details

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Aggregate intrinsic value of options exercised	$ 39
Exercise of stock options, shares	116,586	0
Options Granted, Weighted-average grant-date fair value	$ 0.79	$ 1.23
Total fair value of restricted stock units vested	$ 1,386	$ 4
Unrecognized stock-based compensation expenses	$ 11,488
Unrecognized stock-based compensation expense, period for recognition	2 years 2 months 15 days

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($) Segment	Dec. 31, 2022 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of operating segment \| Segment	1
Operating lease assets	$ 2,267	$ 1,057
Operating lease liabilities	$ 2,384

Stock-Based Compensation - Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board of Directors (Detail)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected option life (years)	6 years	5 years 11 months 15 days
Risk-free interest rate	3.82%	1.80%
Expected volatility	83.36%	80.22%
Expected dividend yield	0.00%	0.00%

Stockholders' Equity

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Stockholders' Equity

9. Stockholders’ Equity

Common Stock

As of June 30, 2023 and December 31, 2022, the authorized capital stock of the Company included 150,000,000 shares of common stock, $0.0001 par value and 10,000,000 shares of undesignated preferred stock. As of June 30, 2023 and December 31, 2022, no undesignated preferred stock was outstanding.

As of June 30, 2023, no cash dividends have been declared or paid.

Common Stock Reserved for Future Issuance

As of June 30, 2023 and December 31, 2022, the Company has reserved the following shares of common stock for future issuance:


	June 30, 2023		December 31, 2022
Shares reserved for exercise of outstanding stock options		7,569,190		9,423,271
Shares reserved for vesting of restricted stock units		1,673,025		940,392
Shares reserved for issuance under the 2018 Stock Option and Grant Plan		5,519,799		5,005,295
Shares reserved for issuance under the 2018 Employee Stock Purchase Plan		1,445,752		1,467,026
Shares reserved for issuance under the 2019 Inducement Plan		947,554		786,656
Shares reserved for issuance under the 2020 Inducement Plan		1,700,000		1,637,000
Total shares of authorized common stock reserved for future issuance		18,855,320		19,259,640

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481004/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding beginning balance	9,423,271
Number of options, Granted	123,501
Number of options, Exercised	(116,586)	0
Number of options, Cancelled or forfeited	(1,860,996)
Number of options, Outstanding ending balance	7,569,190		9,423,271
Number of options, Exercisable	4,180,445
Weighted average exercise price, Outstanding beginning balance	$ 7.26
Weighted average exercise price, Granted	1.09
Weighted average exercise price, Exercised	0.61
Weighted average exercise price, Cancelled or forfeited	5.66
Weighted average exercise price, Outstanding ending balance	7.65		$ 7.26
Weighted average exercise price, Exercisable	$ 10.79
Weighted average remaining contractual term, Outstanding balance	5 years 5 months 8 days		8 years 1 month 20 days
Weighted average remaining contractual term, Exercisable	4 years 3 months 14 days
Aggregate intrinsic value, Outstanding balance	$ 233		$ 22
Aggregate intrinsic value, Exercisable	$ 7

Supplemental Balance Sheet Information - Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Research and development expenses	$ 4,271	$ 6,122
Compensation and benefit costs	3,693	4,175
Consulting and professional fees	375	1,224
Other liabilities	4	211
Accrued expenses and other current liabilities	$ 8,343	$ 11,732

License Agreements

6 Months Ended

Jun. 30, 2023

License Agreements [Abstract]

License Agreements

3. License and Purchase Agreements

Agreement with The University of Manchester

On September 30, 2020, the Company entered into an agreement (“MPSII License Agreement”) with The University of Manchester, England (“UoM”), whereby UoM granted to the Company an exclusive worldwide license under certain patent and other intellectual property rights, subject to certain retained rights, to develop, commercialize and sell an ex vivo lentiviral gene therapy for use in the treatment of Hunter syndrome, or mucopolysaccharidosis type II (“MPSII”). As consideration for the MPSII License Agreement, the Company agreed to pay UoM an upfront, one-time fee of $8,000, which was recognized as research and development expense during the year ended December 31, 2020.

As part of the agreement, the Company is obligated to make milestone payments of up to an aggregate of $80,000 upon the achievement of specified development and regulatory milestones, to pay royalties, on a product-by-product and country-by-country basis, of a mid-single digit percentage based on net sales of products licensed under the agreement and to pay a low double digit percentage of any sublicense fees received by the Company. During the third quarter of 2022, a $2,000 milestone payment under the MPSII License Agreement became due following the date of regulatory approval of the CTA for the investigator-sponsored Phase 1/2 clinical trial sponsored by UoM. The next anticipated payment milestones under the MPSII License Agreement is $4,000 upon the dosing of the first patient in the investigator-sponsored Phase 1/2 clinical trial sponsored by UoM.

Unless terminated earlier, the agreement expires upon the later of 15 years from the effective date or the expiration of the last valid claim of the licensed patents, subject to certain surviving rights and obligations. UoM and the Company can each terminate the agreement in the event of the bankruptcy or insolvency of the other party, or a material breach by the other party and failure to cure such breach within a certain period of time. UoM has the right to terminate the agreement in the event of certain actions relating to challenge or opposition to the licensed intellectual property brought by the Company or its affiliates or sublicensees.

Concurrently with the MPSII License Agreement, the Company entered into a collaborative research funding agreement with UoM (“CRFA”). Under the CRFA, the Company has agreed to fund the budgeted costs of an investigator-sponsored Phase 1/2 clinical trial to be sponsored by UoM in connection with the development activities under the MPSII License Agreement, which are currently expected to equal approximately £9,900 in the aggregate.

For the three months ended June 30, 2023, the Company did not incur costs related to the CRFA. For the three months ended June 30, 2022, the Company incurred $417 related to the CRFA. For the six months ended June 30, 2023 and 2022, the Company incurred $1,610 and $1,380 related to the CRFA, respectively.

Agreements with University Health Network (“UHN”)

Fabry License Agreement—

On January 27, 2016, the Company entered into an agreement with UHN, pursuant to which UHN granted the Company an option to enter into an exclusive license under the UHN intellectual property related to Fabry disease in accordance with the pre-negotiated licensing terms. On November 4, 2016, the Company exercised its option and entered into a license agreement with UHN, pursuant to which UHN granted the Company an exclusive worldwide license under certain intellectual property rights and a non-exclusive worldwide license under certain know-how, in each case subject to certain retained rights, to develop, commercialize and sell products for use in the treatment of Fabry disease. In addition, for three years following the execution of the agreement, UHN granted the Company an exclusive option to obtain a license under certain improvements to the licensed intellectual property rights as well as an option to negotiate a license under certain other improvements.

Under this agreement, the Company paid an option fee of CAD $20, an upfront license fee of CAD $75, plus the annual license maintenance fee for the first year. Thereafter, the Company is also required to pay UHN future annual license maintenance fees until the first sale of a licensed product in certain markets. The Company is also obligated to make future milestone payments in an aggregate amount of up to CAD $2,450 upon the achievement of specified milestones as well as royalties on a country-by-country basis of a low to mid-single-digit percentage of annual net sales of licensed products and a lower single-digit royalty percentage in certain circumstances. Additionally, the Company has agreed to pay a low double-digit royalty percentage of all sublicensing revenue.

The agreement requires the Company to meet certain performance milestones within specified timeframes. UHN may terminate the agreement if the Company fails to meet these performance milestones despite using commercially reasonable efforts and the Company is unable to reach agreement with UHN on revised timeframes. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis upon the latest to occur of the expiration or termination of the last valid claim under the licensed intellectual property rights in such country, the tenth anniversary of the first commercial sale of such licensed product in such country and the expiration of any applicable regulatory exclusivity in such country.

Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products. UHN can terminate the agreement if the Company fails to make any payments within a specified period after receiving written notice of such failure, or in the event that the Company fails to obtain or maintain insurance. Either the Company or UHN may terminate the license agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company can voluntarily terminate the agreement with prior notice to UHN.

For the three months ended June 30, 2023 and 2022, the Company did not incur any research and development expense related to this agreement with UHN for reimbursable funded study trial costs. For the six months ended June 30, 2023 and 2022, the Company recorded research and development expense related to this agreement with UHN of $34 and $24, respectively, which consists of reimbursable funded study trial costs. No milestone or maintenance fees were incurred related to this agreement in the three and six months ended June 30, 2023 and 2022.

Interleukin 12 License Agreement—

On January 27, 2016, the Company entered into an exclusive license agreement with UHN, pursuant to which UHN granted the Company a license to certain patent rights for the commercial development, manufacture, distribution and use of any products or processes resulting from development of those patent rights related to Interleukin 12. Upon execution of this agreement, the Company paid an upfront license fee of CAD $264. In addition, as part of the initial consideration for the license, the Company issued to UHN 1,161,665 shares of the Company’s common stock and agreed to pay UHN up to $2,000 upon the closing of an IPO if certain criteria are met. The fair value of the shares issued to UHN of $480 and the upfront fee was expensed upon the execution of the agreement. Upon the closing of the IPO in 2018, as the criteria were met, the Company paid UHN $2,000. The Company is also required to pay UHN future annual license maintenance fees of CAD $50 on each anniversary of the effective date of the license agreement prior to expiration or termination and potential future milestone payments of up to CAD $19,275 upon the achievement of specified clinical and regulatory milestones. The Company also agreed to pay UHN royalties of a low single-digit percentage of net sales of licensed products sold by the Company. If the Company grants any sublicense rights under the license agreement, the Company has agreed to pay UHN a low double-digit royalty percentage of any sublicense income received by the Company.

The agreement requires the Company to meet certain diligence requirements based upon specified milestones. The agreement expires on the later of the date the last patent rights expire in the last country or ten years from the date of first sale. UHN can terminate the agreement if the Company fails to make any payments within a specified period after receiving written notice of such failure, or in the event that the Company fails to obtain or maintain insurance. The Company can voluntarily terminate the agreement with prior notice to UHN. Either the Company or UHN may terminate the license agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time.

For the three months ended June 30, 2023 the Company did not incur any costs related to this agreement with UHN. For the three months ended June 30, 2022, the Company recorded research and development expense related to this agreement with UHN of $39. For the six months ended June 30, 2023 and 2022, the Company recorded research and development expense related to this agreement with UHN of $37 and $39, respectively. No milestone fees were incurred related to this agreement in the three and six months ended June 30, 2023 and 2022.

Agreement with BioMarin Pharmaceutical Inc. (“BioMarin”)

On August 31, 2017, the Company entered into a license agreement with BioMarin, pursuant to which BioMarin granted the Company an exclusive worldwide license under certain intellectual property rights owned or controlled by BioMarin to develop, commercialize and sell products for use in the treatment of Pompe disease. The license agreement was amended in February 2018 and again in January 2020 to, among things, provide that BioMarin would supply the Company with certain technology materials. As consideration for this agreement, the Company paid an upfront license fee of $500 in cash and issued 233,765 shares of Series B Preferred Stock to BioMarin at the time of the Company’s Series B Preferred Stock financing in January 2018. The Company has a license agreement with BioMarin, pursuant to which BioMarin granted the Company an exclusive worldwide license under certain intellectual property rights owned or controlled by BioMarin to develop, commercialize and sell products for use in the treatment of Pompe disease. The Company is also obligated to make future milestone payments of up to $13,000 upon the achievement of certain specified milestones and agreed to pay BioMarin royalties of a low single-digit percentage of net sales of licensed products sold by the Company or its affiliates covered by patent rights in a relevant country.

The Company has recognized no expenses related to the license for the three and six months ended June 30, 2023 and 2022.

Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. BioMarin and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon written notice to BioMarin. BioMarin has the right to terminate the agreement upon the Company’s bankruptcy or insolvency, or in the event of any challenge or opposition to the licensed patent rights or related actions brought by the Company or its affiliates or sublicensees, or if the Company, its affiliates or sublicensees knowingly assist a third-party in challenging or otherwise opposing the licensed patent rights, except as required under a court order or subpoena.

Agreement with Papillon Therapeutics, Inc. (previously GenStem Therapeutics, Inc.)

On October 2, 2017, the Company entered into a license agreement with GenStem, pursuant to which GenStem granted the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights owned or controlled by GenStem to develop, commercialize and sell products for use in the treatment of cystinosis. Under this agreement, the Company paid an upfront license fee of $1,000 and is required to make payments upon completion of certain milestones up to an aggregate of $16,000. The Company also agreed to pay GenStem a tiered mid to high single-digit royalty percentage on annual net sales of licensed products as well as a low double-digit percentage of sublicense income received from certain third-party licensees. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis on the eleventh anniversary of the first commercial sale of such licensed product in such country or the expiration of the last valid claim under the licensed patent rights covering such licensed product in such country, whichever is later. Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. GenStem and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon the specified prior written notice to GenStem. In October 2021, the Company received noticed that the license agreement with GenStem had been assigned to Papillon Therapeutics, Inc. (“Papillon”). On June 9, 2023, in connection with the close of the Asset Purchase Agreement, discussed and defined above, the Company transferred this agreement to Novartis.

The Company has recognized no expenses related to this agreement for the three and six months ended June 30, 2023 and 2022.

Agreement with Lund University Rights Holders

On November 17, 2016, the Company entered into a license agreement with affiliates of Lund University, along with certain other relevant rights holders that may be added from time to time, pursuant to which such rights holders granted to the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights to develop, commercialize and sell products in any and all uses relevant to Gaucher disease. As consideration for the license, the Company is required to make payments in connection with the achievement of certain milestones up to an aggregate of $550. The agreement expires on the latest of (i) the twentieth anniversary of the end of a certain research project the Company is funding pursuant to an agreement with Lund University, (ii) the expiration of the term of any patent filed on the licensed rights that covers a licensed product, (iii) the expiration of any applicable marketing exclusivity right and (iv) such time that neither the Company nor any sublicensees, partners or contractors are commercializing a licensed product. Either the Company or the rights holders acting together may terminate the license agreement if the other such party commits a material breach and fails to cure such breach within a certain period of time, or if the other party enters into liquidation, becomes insolvent, or enters into composition or statutory reorganization proceedings.

The Company has recognized no expenses related to this agreement for the three and six months ended June 30, 2023 and 2022.

Sale of Cystinosis Program

On May 19, 2023, the Company entered into the Asset Purchase Agreement with Novartis, providing for the sale of the Company’s cystinosis gene therapy program (designated AVR-RD-04) and all other assets of the Company specifically related to this program. In addition, pursuant to the Asset Purchase Agreement, the Company has granted an exclusive license to Novartis to use certain intellectual property of the Company, which consists of certain proprietary elements of the Company’s plato® gene therapy platform technology specifically within the field of cystinosis. The foregoing transactions contemplated by the Asset Purchase Agreement are referred to as the “Asset Sale.” The Company has also agreed not to assert claims against Novartis for violations of certain other Company intellectual property rights in connection with Novartis’s exercise of the exclusive license granted to it under the Asset Purchase Agreement, and for violations of the licensed intellectual property, except in connection with activities by Novartis in the fields of Gaucher disease, Pompe disease, Hunter syndrome and Fabry disease, or indemnification claims under the Asset Purchase Agreement. The aggregate consideration to the Company consisted of a cash payment of $87,500 upon closing of the transaction.

The Asset Purchase Agreement contains certain customary representations, warranties and covenants. The Asset Purchase Agreement also contains customary indemnification provisions pursuant to which the parties agree to indemnify each other for certain matters, including, among other things, breaches of certain representations, warranties and covenants in connection with the Asset Sale, subject to specified caps and limitations. The Company has also agreed to a covenant that would prohibit the Company from engaging in specified activities that would compete with the cystinosis business, for a period of 5 years, subject to certain limitations and exceptions. The Company completed the Asset Sale on June 9, 2023. For the three and six months ended June 30, 2023 the Company recognized $83,736 as a gain on asset sale, net of $3,764 transaction costs, related to legal, accounting, and financial advisory services and transferred prepaid assets.

Fair Value Measurement (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on Recurring Basis


	Fair Value Measurements as of June 30, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	123,363	$	—	$	—	$	123,363
	$	123,363	$	—	$	—	$	123,363


	Fair Value Measurements as of December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	91,095	$	—	$	—	$	91,095
	$	91,095	$	—	$	—	$	91,095

Supplemental Balance Sheet Information - Summary of Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Restricted Cash and Investments [Abstract]
Restricted cash	$ 283	$ 283
Restricted cash, net of current portion	$ 400	$ 0

Subsequent Events

6 Months Ended

Jun. 30, 2023

Subsequent Events [Abstract]

Subsequent Events [Text Block]

13. Subsequent Events

On July 12, 2023, the Company announced its intention to explore strategic alternatives. In connection therewith, following a comprehensive review of the Company’s business, on July 6, 2023, the Company’s Board approved a plan to halt further development of its programs and to conduct a comprehensive exploration of strategic alternatives focused on maximizing stockholder value. The decision was not related to any safety or medical issues or negative regulatory feedback related to the Company’s programs. The Board also approved a reduction in the Company’s workforce by approximately 50% across different areas and functions in the Company (the “Workforce Reduction”). The Workforce Reduction was substantially completed by the end of July 2023. The Company informed affected employees in the Workforce Reduction on July 12, 2023. The Company’s remaining employees are expected to primarily focus on activities relating to halting further development of the Company’s programs, the pursuit of strategic alternatives, and the provision of services under the previously disclosed Separation Services Agreement between the Company and Novartis in connection with the sale to Novartis of the Company’s cystinosis gene therapy program. Affected employees in the Workforce Reduction will be offered separation benefits, including severance payments. The Company estimates that the severance and termination-related costs will total approximately $2.8 million in the aggregate and expects to primarily record these charges in the third quarter of 2023. The Company expects that payments of these costs will substantially be made through the end of the third quarter of 2023.

Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Components of Basic and Diluted Earnings Per Share

The following table sets forth the computation of the Company’s basic and diluted net income (loss) per share for the three and six months ended June 30, 2023 and 2022 (in thousands, except share and per share amounts):


	Three Months Ended June 30,					Six Months Ended June 30,
	2023		2022			2023		2022
Numerator:
Net income (loss) attributable to common stockholders—basic and diluted	$	67,476	$	(28,054	)	$	42,519	$	(57,887	)
Denominator:
Weighted-average common shares outstanding—basic		44,134,436		43,696,564			44,085,977		43,695,769
Weighted-average common shares outstanding—diluted		44,280,606		43,696,564			44,271,016		43,695,769
Net income (loss) per share applicable to common stockholders—basic	$	1.53	$	(0.64	)	$	0.96	$	(1.32	)
Net income (loss) per share applicable to common stockholders—diluted	$	1.52	$	(0.64	)	$	0.96	$	(1.32	)

Schedule of Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share

The Company excluded the following potential common shares from the computation of diluted net income (loss) per share attributable to common stockholders for the three and six months ended June 30, 2023 and 2022 because including them would have had an anti-dilutive effect:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Options to purchase common stock		8,114,210		8,913,316		8,606,761		8,913,316
Restricted stock units		1,711,124		893,259		1,570,009		893,259

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2021	$ 169,476	$ 4	$ 553,014	$ (383,542)
Beginning balance, shares at Dec. 31, 2021		43,652,000
Stock-based compensation expense	$ 6,611		6,611
Exercise of stock options, shares	0
Proceeds from issuance of ESPP shares	$ 143		143
Issuance of common stock under 2018 employee stock purchase plan, shares		44,000
Net Income (Loss)	(57,887)			(57,887)
Ending balance at Jun. 30, 2022	118,343	$ 4	559,768	(441,429)
Ending balance, shares at Jun. 30, 2022		43,696,000
Beginning balance at Mar. 31, 2022	143,163	$ 4	556,534	(413,375)
Beginning balance, shares at Mar. 31, 2022		43,696,000
Stock-based compensation expense	3,234		3,234
Net Income (Loss)	(28,054)			(28,054)
Ending balance at Jun. 30, 2022	118,343	$ 4	559,768	(441,429)
Ending balance, shares at Jun. 30, 2022		43,696,000
Beginning balance at Dec. 31, 2022	75,370	$ 4	564,798	(489,432)
Beginning balance, shares at Dec. 31, 2022		43,916,000
Stock-based compensation expense	4,064		4,064
Exercise of stock options	$ 71		71
Exercise of stock options, shares	116,586	117,000
Vesting of restricted stock awards and units, shares		254,000
Proceeds from issuance of ESPP shares	$ 13		13
Issuance of common stock under 2018 employee stock purchase plan, shares		21,000
Net Income (Loss)	42,519			42,519
Ending balance at Jun. 30, 2023	122,037	$ 4	568,946	(446,913)
Ending balance, shares at Jun. 30, 2023		44,308,000
Beginning balance at Mar. 31, 2023	52,998	$ 4	567,383	(514,389)
Beginning balance, shares at Mar. 31, 2023		44,088,000
Stock-based compensation expense	1,534		1,534
Exercise of stock options	29		29
Exercise of stock options, shares		71,000
Vesting of restricted stock awards and units, shares		149,000
Net Income (Loss)	67,476			67,476
Ending balance at Jun. 30, 2023	$ 122,037	$ 4	$ 568,946	$ (446,913)
Ending balance, shares at Jun. 30, 2023		44,308,000

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 830
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480167/946-830-55-12

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(19))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.6-05(4))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(4)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(6))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-09(7))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 14: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480418/310-10-S99-2

+ Details

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board of Directors

The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis:


	Six Months Ended June 30,
	2023			2022
Expected option life (years)		6.00			5.96
Risk-free interest rate		3.82	%		1.80	%
Expected volatility		83.36	%		80.22	%
Expected dividend yield		—	%		—	%

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the six months ended June 30, 2023:


	Number of Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2022		9,423,271		$	7.26		8.14	$	22
Granted		123,501		$	1.09
Exercised		(116,586	)	$	0.61
Cancelled or forfeited		(1,860,996	)	$	5.66
Outstanding as of June 30, 2023		7,569,190		$	7.65		5.44	$	233
Exercisable as of June 30, 2023		4,180,445		$	10.79		4.29	$	7

Summary of Restricted Common Stock Units

The following table summarizes the Company’s restricted common stock units for the six months ended June 30, 2023:


	Number of Shares			Weighted- Average Grant Date Fair Value
Issued and unvested as of December 31, 2022		940,392		$	3.62
Granted		1,478,117		$	1.69
Vested		(253,460	)	$	5.47
Forfeited, cancelled or expired		(492,024	)	$	1.71
Issued and unvested as of June 30, 2023		1,673,025		$	2.19

Schedule of Stock-based Compensation Expense

Stock-based compensation expense was allocated as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	669	$	783	$	1,291	$	1,721
General and administrative		865		2,451		2,773		4,890
Total stock-based compensation expense	$	1,534	$	3,234	$	4,064	$	6,611

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2023	Aug. 03, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	AVRO
Entity Registrant Name	AVROBIO, INC.
Entity Central Index Key	0001681087
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		44,530,744
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-38537
Entity Tax Identification Number	81-0710585
Entity Address, Address Line One	100 Technology Square
Entity Address, Address Line Two	Sixth Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	914-8420
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	150,000,000	150,000,000
Common stock, issued	44,308,000	43,916,000
Common stock, outstanding	44,308,000	43,916,000

Supplemental Balance Sheet Information - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 6,706	$ 6,698
Less: Accumulated depreciation and amortization	(4,421)	(3,804)
Property and equipment, net	2,285	2,894
Laboratory and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	5,973	5,967
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	629	629
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, gross	$ 104	$ 102

Earnings Per Share - Components of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net income (loss) attributable to common stockholder basic	$ 67,476	$ (28,054)	$ 42,519	$ (57,887)
Net income (loss) attributable to common stockholders diluted	$ 67,476	$ (28,054)	$ 42,519	$ (57,887)
Denominator:
Weighted-average common shares outstanding basic	44,134,436	43,696,000	44,085,977	43,695,769
Weighted-average number of common shares outstanding - diluted	44,280,606	43,696,000	44,271,016	43,695,769
Net income (loss) per share applicable to common stockholders basic	$ 1.53	$ (0.64)	$ 0.96	$ (1.32)
Net income (loss) per share applicable to common stockholders diluted	$ 1.52	$ (0.64)	$ 0.96	$ (1.32)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480175/815-40-65-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-7

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(27))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(23))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 52
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482635/260-10-55-52

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-7

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-11

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483443/250-10-50-4

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 6.B)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-5

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-10

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-11

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

+ References + Details

Net Loss Per Share

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

11. Net Income (Loss) Per Share


	Three Months Ended June 30,					Six Months Ended June 30,
	2023		2022			2023		2022
Numerator:
Net income (loss) attributable to common stockholders—basic and diluted	$	67,476	$	(28,054	)	$	42,519	$	(57,887	)
Denominator:
Weighted-average common shares outstanding—basic		44,134,436		43,696,564			44,085,977		43,695,769
Weighted-average common shares outstanding—diluted		44,280,606		43,696,564			44,271,016		43,695,769
Net income (loss) per share applicable to common stockholders—basic	$	1.53	$	(0.64	)	$	0.96	$	(1.32	)
Net income (loss) per share applicable to common stockholders—diluted	$	1.52	$	(0.64	)	$	0.96	$	(1.32	)


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Options to purchase common stock		8,114,210		8,913,316		8,606,761		8,913,316
Restricted stock units		1,711,124		893,259		1,570,009		893,259