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Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Numerator:
Net Income (Loss)	$ (14,041)	$ (11,625)
Denominator:
Weighted-average shares of common stock outstanding, basic	43,944,946	41,096,231
Weighted-average shares of common stock outstanding,diluted	43,944,946	41,096,231
Net loss per share, basic	$ (0.32)	$ (0.28)
Net loss per share,diluted	$ (0.32)	$ (0.28)

- Definition

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

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+ 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.

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+ Details

- Definition

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

+ References

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+ Details

Related Party Transactions	3 Months Ended
Mar. 31, 2025
Related Party Transactions [Abstract]
Related Party Transactions	11. Related Party Transactions Effective December 20, 2024, Kirk Ways, M.D., a member of the board of the directors, began serving as the Company’s interim Chief Medical Officer pursuant to a consulting agreement. During the three months ended March 31, 2025, the Company recognized compensation expense of $0.3 million which is included in research and development expenses on the statement of operations and comprehensive loss. As of March 31, 2025, the Company accrued compensation expense of $0.1 million which is included in accrued expenses and other current liabilities on the balance sheet.

Related Party Transactions

3 Months Ended

Mar. 31, 2025

Related Party Transactions

11. Related Party Transactions

Effective December 20, 2024, Kirk Ways, M.D., a member of the board of the directors, began serving as the Company’s interim Chief Medical Officer pursuant to a consulting agreement. During the three months ended March 31, 2025, the Company recognized compensation expense of $0.3 million which is included in research and development expenses on the statement of operations and comprehensive loss. As of March 31, 2025, the Company accrued compensation expense of $0.1 million which is included in accrued expenses and other current liabilities on the balance sheet.

- 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.

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+ Details

License and Purchase Agreements	3 Months Ended
Mar. 31, 2025
Research and Development [Abstract]
License and Purchase Agreements	7. License and Purchase Agreements Eli Lilly and Company In May 2016, the Company entered into a license agreement (the “Lilly License Agreement”), with Eli Lilly and Company (“Lilly”). Pursuant to the terms of the Lilly License Agreement, Lilly granted the Company an exclusive, worldwide, royalty bearing, sublicensable license under certain technology, patent rights, know-how and proprietary materials related to certain compounds, to research, develop, and commercialize such compounds for all pharmaceutical uses. As partial consideration for the rights granted to the Company under the Lilly License Agreement, the Company made a one-time upfront payment to Lilly of $0.8 million during the year ended December 31, 2016, which was recorded as research and development expense as there was no alternative use due to the early stage of the technology. The Company is also required to pay Lilly up to an aggregate of $23.0 million upon the achievement, during the time the Lilly License Agreement remains in effect, of certain milestones relating to the clinical development and commercial sales of products licensed under the Lilly License Agreement. Such payments are for predetermined fixed amounts, are paid only upon the first occurrence of each event, and are due shortly after achieving the applicable milestone. In addition, the Company is required to pay Lilly tiered royalties on annual worldwide net sales with rates ranging from mid-single-digits to sub-teens. No additional amounts were paid by the Company to Lilly during any of the periods presented, nor were due as of such dates pursuant to the Lilly License Agreement. The Lilly License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until the later of (i) the tenth anniversary of the date of first commercial sale in such country, (ii) the expiration in such country of the last-to-expire licensed patent having a valid claim covering the manufacture, use or sale of the licensed product as commercialized in such country, and (iii) the expiration of any data or regulatory exclusivity period for the licensed product in such country. Kaken Pharmaceutical Co, Ltd. On January 5, 2023, the Company entered into a collaboration and license agreement (the “Kaken License Agreement”) with Kaken Pharmaceutical Co, Ltd. (“Kaken”). Under the terms of the Kaken License Agreement, the Company granted to Kaken the exclusive right to develop, manufacture and commercialize the Company’s product candidate, tildacerfont, for the treatment of CAH in Japan. Pursuant to the Kaken License Agreement, Kaken will be responsible for securing and maintaining regulatory approvals necessary to commercialize tildacerfont in Japan. The Company will retain all rights to tildacerfont in all other geographies. Pursuant to the Kaken License Agreement, Kaken made an upfront payment to the Company of $15.0 million in April 2023. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of approximately $65.0 million (at exchange rates in effect on the date of the Kaken License Agreement) upon the achievement of specified milestones related to the development, regulatory approval and commercialization of tildacerfont in Japan, including the achievement of specified net sales thresholds, if approved. Kaken has agreed to pay the Company a non-creditable, non-refundable specified purchase price for each unit of Company-manufactured product supplied to Kaken for commercial sale. In addition, the Company will also be entitled to receive a royalty for each unit of non-Company manufactured product sold equal to a range of double-digit percentages up to the mid-twenties based on annual net sales of tildacerfont in Japan. Both the purchase price for each unit and the royalty rate are subject to reduction in certain circumstances as specified in the Kaken License Agreement. Kaken’s obligation to pay royalties will continue for ten years after the first commercial sale in Japan or, if later, until the expiration of regulatory exclusivity of tildacerfont or the expiration of the last valid claim of a Company-licensed patent covering tildacerfont in Japan. The Company identified a combined performance obligation consisting of the license and know-how granted to Kaken as well as certain non-contingent research and development activities. The Company determined that the transaction price at the inception of the Kaken License Agreement consisted of the upfront payment of $15.0 million. The transaction price was recognized as revenue using the cost-based input method over the estimated period of its non-contingent research and development obligations, which was approximately two years. During the three months ended March 31, 2024, the Company recognized collaboration revenue of $2.0 million. As of December 31, 2024, the full transaction price has been recognized. HMNC Holding GmbH In May 2024, the Company entered into a license, development and option agreement (the “HMNC Agreement”) with HMNC Holding GmbH (“HMNC”). Under the terms of the HMNC Agreement, HMNC will fund and conduct a Phase 2 proof-of-concept study of tildacerfont in MDD patients, who will be screened using Cortibon Genetic Selection Tool (“Cortibon”), HMNC’s proprietary genetic selection tool. The Company has an option to in-license exclusive worldwide rights to Cortibon after completion of the study, if results are positive. If the Company exercises its option, it will be responsible for the future worldwide development and commercialization of tildacerfont and Cortibon for the treatment of MDD under a collaboration framework that leverages HMNC’s ongoing expertise in precision psychiatry and companion diagnostics. Pursuant to the license terms, HMNC would be entitled to receive certain milestone payments and tiered royalties on net sales of tildacerfont in MDD. No amounts were paid to the Company during any of the periods presented, nor were any due as of such dates pursuant to the HMNC Agreement. Allievex Corporation On October 4, 2024, the Company entered into that certain Asset Purchase Agreement (the “Allievex Purchase Agreement”) with AVX (ABC), LLC, a Delaware limited liability company, in its sole and limited capacity as the assignee for the benefit of creditors of Allievex Corporation (“Allievex”). Pursuant to the Allievex Purchase Agreement, the Company acquired all intellectual property and inventory relating to Allievex's product candidates and that certain Exclusive License Agreement, by and between BioMarin Pharmaceutical Inc. (“BioMarin”) and Allievex, dated October 22, 2019 (the “BioMarin License Agreement”). As consideration, the Company paid $5.0 million to Allievex in November 2024. The Company also assumed certain liabilities of Allievex of $11.7 million, of which $6.0 million was paid as of March 31, 2025 and the remaining $5.7 million is included in accrued expenses and other current liabilities on the balance sheet. The amount accrued includes certain contingent liabilities that are deemed both probable and estimable. The Company has also recorded an estimated receivable of $1.9 million in other current assets on the balance sheet as contingent consideration expected to be returned related to the assumed liabilities. The receivable is contingent upon the completion of the Allievex bankruptcy proceedings and has been recorded as the Company deems the amount to be both probable and estimable. The Company also incurred transaction costs of $0.3 million. The Company concluded that the assets purchased in conjunction with the Allievex Purchase Agreement represent an asset acquisition whereby the underlying assets comprise in-process research and development assets with no alternative future use. Therefore, the aggregate net acquisition cost of $15.1 million, related to the upfront cash payment, the liabilities assumed and the estimated contingent consideration expected to be returned, was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the year ended December 31, 2024. The Company also assumed the obligations of Allievex to pay BioMarin up to an aggregate of $88.0 million upon the achievement of certain development and regulatory milestones (up to $25.5 million for the first MPSIIIB product) and up to an aggregate of $100.0 million per licensed product upon the achievement of certain sales milestones. In addition, the Company is required to pay to BioMarin certain (i) high-single digit to low-double digit tiered royalties on aggregate annual net sales of licensed MPS IIIB products and (i) mid-to-high single digit tiered royalties on aggregate annual net sales of licensed products other than MPS IIIB products, in each case during the applicable royalty term, subject to certain customary reductions and floors. No amounts were paid by the Company to BioMarin nor were any due as of March 31, 2025 pursuant to the Allievex Purchase Agreement. The Company may terminate the BioMarin License Agreement at any time for convenience upon prior written notice provided within a specified period of time. BioMarin may terminate the BioMarin License Agreement upon written notice if we (i) challenge the validity, enforceability or scope of any of the patents licensed by us under the BioMarin License Agreement, subject to certain conditions, or (ii) cease all material research and development activity for any licensed product for a specified period of time, subject to certain exceptions. Either the Company or BioMarin may also terminate the BioMarin License Agreement (i) in the event the other party shall have materially breached its obligations thereunder and such default shall have continued for a specified period after written notice thereof or (ii) upon the bankruptcy or insolvency of the other party. Twist Bioscience Corporation On December 20, 2024, the Company entered into an antibody license agreement (the “Twist Antibody License Agreement”) with Twist Bioscience Corporation (“Twist”). Under the terms of the Twist License Agreement, the Company obtained (i) a license for purposes of evaluating a certain antibody during the research term and (ii) an exclusive option to acquire an exclusive, non-transferable and royalty-bearing world-wide license, with the right to sublicense, to (a) research and develop the antibody, (b) incorporate the antibody into products and (c) commercialize such products (the “Twist Option”). The Twist Option can be exercised during the research term, which is initially six months and will expire in June 2025. As consideration, the Company paid $0.5 million to Twist in February 2025. The Company can extend the research term by an additional six months by making an extension payment of $0.5 million. The Company can exercise the Twist Option by making an exercise payment of $1.5 million. As of March 31, 2025, the research term has not been extended and the Twist Option has not been exercised. The Company concluded that the rights acquired under the Twist License Agreement have no alternative future use. Therefore, the consideration paid of $0.5 million was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the year ended December 31, 2024. The Company is also required to pay Twist up to an aggregate of $5.0 million upon the achievement of certain regulatory milestone and up to $125.0 million per product upon the achievement of certain sales milestones by each such product. In addition, the Company is required to pay Twist tiered royalties on annual net sales with rates ranging in the mid to high-single digit. No additional amounts were paid by the Company to Twist nor were due as of March 31, 2025 pursuant to the Twist License Agreement. The Twist License Agreement will remain in effect until the expiration of the research term except if the Company exercises the Twist Option, then the Twist License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until expiration. HBM Alpha Therapeutics, Inc. On January 15, 2025, the Company entered into a collaboration and license agreement (the “HBM License Agreement”) with HBM Alpha Therapeutics, Inc. (“HBM”). Under the terms of the HBM License Agreement, HBM granted the Company a limited exclusivity, royalty bearing, and sublicensable license to certain technology, patent rights, manufacturing rights, know-how, and proprietary materials relating to certain compounds developed by HBM. As consideration, the Company made a one-time upfront payment to HBM of $5.0 million in February 2025. Additionally, in January 2025, the Company issued pre-funded warrants to HBM and its affiliates that in total will be equal to 4.99% of the Company's outstanding common stock as of the date of exercise of such pre-funded warrants. The exercise period for the pre-funded warrants expires in June 2025. The Company concluded that the rights acquired under the HBM License Agreement have no alternative future use. Therefore, the consideration paid of $5.0 million, along with the initial fair value of the pre-funded warrants issued of $0.7 million (see Note 3 “Fair Value Measurements — Warrant Liability”), was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the three months ended March 31, 2025. The Company is also obligated to pay HBM up to an aggregate of $390.0 million upon the achievement of certain development, regulatory, and sales milestones. In addition, the Company is required to pay to HBM certain mid to high-single digit tiered royalties on aggregate annual net sales of licensed products during the applicable royalty term, subject to certain customary reductions. The Company may terminate the HBM License Agreement on a licensed product-by-licensed product basis or in its entirety at any time for convenience upon prior written notice provided within a specified period of time. Either the Company or HBM may also terminate the HBM License Agreement (i) in the event the other party shall have materially breached its obligations thereunder and such default shall have continued for a specified period after written notice thereof or (ii) upon the bankruptcy or insolvency of the other party. HBM may terminate the HBM License Agreement upon prior written notice if the Company (i) ceases all development or commercialization activities for a specified period of time, subject to certain exceptions, or (ii) challenges the validity, enforceability or scope of any of the patents licensed by the Company to HBM under the HBM License Agreement, subject to certain conditions.

License and Purchase Agreements

3 Months Ended

Mar. 31, 2025

Research and Development [Abstract]

License and Purchase Agreements

7. License and Purchase Agreements

Eli Lilly and Company

In May 2016, the Company entered into a license agreement (the “Lilly License Agreement”), with Eli Lilly and Company (“Lilly”). Pursuant to the terms of the Lilly License Agreement, Lilly granted the Company an exclusive, worldwide, royalty bearing, sublicensable license under certain technology, patent rights, know-how and proprietary materials related to certain compounds, to research, develop, and commercialize such compounds for all pharmaceutical uses.

As partial consideration for the rights granted to the Company under the Lilly License Agreement, the Company made a one-time upfront payment to Lilly of $0.8 million during the year ended December 31, 2016, which was recorded as research and development expense as there was no alternative use due to the early stage of the technology. The Company is also required to pay Lilly up to an aggregate of $23.0 million upon the achievement, during the time the Lilly License Agreement remains in effect, of certain milestones relating to the clinical development and commercial sales of products licensed under the Lilly License Agreement. Such payments are for predetermined fixed amounts, are paid only upon the first occurrence of each event, and are due shortly after achieving the applicable milestone. In addition, the Company is required to pay Lilly tiered royalties on annual worldwide net sales with rates ranging from mid-single-digits to sub-teens. No additional amounts were paid by the Company to Lilly during any of the periods presented, nor were due as of such dates pursuant to the Lilly License Agreement.

The Lilly License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until the later of (i) the tenth anniversary of the date of first commercial sale in such country, (ii) the expiration in such country of the last-to-expire licensed patent having a valid claim covering the manufacture, use or sale of the licensed product as commercialized in such country, and (iii) the expiration of any data or regulatory exclusivity period for the licensed product in such country.

Kaken Pharmaceutical Co, Ltd.

On January 5, 2023, the Company entered into a collaboration and license agreement (the “Kaken License Agreement”) with Kaken Pharmaceutical Co, Ltd. (“Kaken”). Under the terms of the Kaken License Agreement, the Company granted to Kaken the exclusive right to develop, manufacture and commercialize the Company’s product candidate, tildacerfont, for the treatment of CAH in Japan. Pursuant to the Kaken License Agreement, Kaken will be responsible for securing and maintaining regulatory approvals necessary to commercialize tildacerfont in Japan. The Company will retain all rights to tildacerfont in all other geographies.

Pursuant to the Kaken License Agreement, Kaken made an upfront payment to the Company of $15.0 million in April 2023. In addition to the upfront payment, the Company is entitled to receive up to an aggregate of approximately $65.0 million (at exchange rates in effect on the date of the Kaken License Agreement) upon the achievement of specified milestones related to the development, regulatory approval and commercialization of tildacerfont in Japan, including the achievement of specified net sales thresholds, if approved. Kaken has agreed to pay the Company a non-creditable, non-refundable specified purchase price for each unit of Company-manufactured product supplied to Kaken for commercial sale. In addition, the Company will also be entitled to receive a royalty for each unit of non-Company manufactured product sold equal to a range of double-digit percentages up to the mid-twenties based on annual net sales of tildacerfont in Japan. Both the purchase price for each unit and the royalty rate are subject to reduction in certain circumstances as specified in the Kaken License Agreement. Kaken’s obligation to pay royalties will continue for ten years after the

first commercial sale in Japan or, if later, until the expiration of regulatory exclusivity of tildacerfont or the expiration of the last valid claim of a Company-licensed patent covering tildacerfont in Japan.

The Company identified a combined performance obligation consisting of the license and know-how granted to Kaken as well as certain non-contingent research and development activities. The Company determined that the transaction price at the inception of the Kaken License Agreement consisted of the upfront payment of $15.0 million. The transaction price was recognized as revenue using the cost-based input method over the estimated period of its non-contingent research and development obligations, which was approximately two years. During the three months ended March 31, 2024, the Company recognized collaboration revenue of $2.0 million. As of December 31, 2024, the full transaction price has been recognized.

HMNC Holding GmbH

In May 2024, the Company entered into a license, development and option agreement (the “HMNC Agreement”) with HMNC Holding GmbH (“HMNC”). Under the terms of the HMNC Agreement, HMNC will fund and conduct a Phase 2 proof-of-concept study of tildacerfont in MDD patients, who will be screened using Cortibon Genetic Selection Tool (“Cortibon”), HMNC’s proprietary genetic selection tool.

The Company has an option to in-license exclusive worldwide rights to Cortibon after completion of the study, if results are positive. If the Company exercises its option, it will be responsible for the future worldwide development and commercialization of tildacerfont and Cortibon for the treatment of MDD under a collaboration framework that leverages HMNC’s ongoing expertise in precision psychiatry and companion diagnostics. Pursuant to the license terms, HMNC would be entitled to receive certain milestone payments and tiered royalties on net sales of tildacerfont in MDD.

No amounts were paid to the Company during any of the periods presented, nor were any due as of such dates pursuant to the HMNC Agreement.

Allievex Corporation

On October 4, 2024, the Company entered into that certain Asset Purchase Agreement (the “Allievex Purchase Agreement”) with AVX (ABC), LLC, a Delaware limited liability company, in its sole and limited capacity as the assignee for the benefit of creditors of Allievex Corporation (“Allievex”). Pursuant to the Allievex Purchase Agreement, the Company acquired all intellectual property and inventory relating to Allievex's product candidates and that certain Exclusive License Agreement, by and between BioMarin Pharmaceutical Inc. (“BioMarin”) and Allievex, dated October 22, 2019 (the “BioMarin License Agreement”).

As consideration, the Company paid $5.0 million to Allievex in November 2024. The Company also assumed certain liabilities of Allievex of $11.7 million, of which $6.0 million was paid as of March 31, 2025 and the remaining $5.7 million is included in accrued expenses and other current liabilities on the balance sheet. The amount accrued includes certain contingent liabilities that are deemed both probable and estimable. The Company has also recorded an estimated receivable of $1.9 million in other current assets on the balance sheet as contingent consideration expected to be returned related to the assumed liabilities. The receivable is contingent upon the completion of the Allievex bankruptcy proceedings and has been recorded as the Company deems the amount to be both probable and estimable. The Company also incurred transaction costs of $0.3 million.

The Company concluded that the assets purchased in conjunction with the Allievex Purchase Agreement represent an asset acquisition whereby the underlying assets comprise in-process research and development assets with no alternative future use. Therefore, the aggregate net acquisition cost of $15.1 million, related to the upfront cash payment, the liabilities assumed and the estimated contingent consideration expected to be returned, was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the year ended December 31, 2024.

The Company also assumed the obligations of Allievex to pay BioMarin up to an aggregate of $88.0 million upon the achievement of certain development and regulatory milestones (up to $25.5 million for the first MPSIIIB product) and up to an aggregate of $100.0 million per licensed product upon the achievement of certain sales milestones. In addition, the Company is required to pay to BioMarin certain (i) high-single digit to low-double digit tiered royalties on aggregate annual net sales of licensed MPS IIIB products and (i) mid-to-high single digit tiered royalties on aggregate annual net sales of licensed products other than MPS IIIB products, in each case during the applicable royalty term, subject to certain customary reductions and floors. No amounts were paid by the Company to BioMarin nor were any due as of March 31, 2025 pursuant to the Allievex Purchase Agreement.

The Company may terminate the BioMarin License Agreement at any time for convenience upon prior written notice provided within a specified period of time. BioMarin may terminate the BioMarin License Agreement upon written notice if we (i) challenge the validity, enforceability or scope of any of the patents licensed by us under the BioMarin License Agreement, subject to certain conditions, or (ii) cease all material research and development activity for any licensed product for a specified period of time, subject to certain exceptions. Either the Company or BioMarin may also terminate the BioMarin License Agreement (i) in the event the other

party shall have materially breached its obligations thereunder and such default shall have continued for a specified period after written notice thereof or (ii) upon the bankruptcy or insolvency of the other party.

Twist Bioscience Corporation

On December 20, 2024, the Company entered into an antibody license agreement (the “Twist Antibody License Agreement”) with Twist Bioscience Corporation (“Twist”). Under the terms of the Twist License Agreement, the Company obtained (i) a license for purposes of evaluating a certain antibody during the research term and (ii) an exclusive option to acquire an exclusive, non-transferable and royalty-bearing world-wide license, with the right to sublicense, to (a) research and develop the antibody, (b) incorporate the antibody into products and (c) commercialize such products (the “Twist Option”). The Twist Option can be exercised during the research term, which is initially six months and will expire in June 2025.

As consideration, the Company paid $0.5 million to Twist in February 2025. The Company can extend the research term by an additional six months by making an extension payment of $0.5 million. The Company can exercise the Twist Option by making an exercise payment of $1.5 million. As of March 31, 2025, the research term has not been extended and the Twist Option has not been exercised.

The Company concluded that the rights acquired under the Twist License Agreement have no alternative future use. Therefore, the consideration paid of $0.5 million was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the year ended December 31, 2024.

The Company is also required to pay Twist up to an aggregate of $5.0 million upon the achievement of certain regulatory milestone and up to $125.0 million per product upon the achievement of certain sales milestones by each such product. In addition, the Company is required to pay Twist tiered royalties on annual net sales with rates ranging in the mid to high-single digit. No additional amounts were paid by the Company to Twist nor were due as of March 31, 2025 pursuant to the Twist License Agreement.

The Twist License Agreement will remain in effect until the expiration of the research term except if the Company exercises the Twist Option, then the Twist License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until expiration.

HBM Alpha Therapeutics, Inc.

On January 15, 2025, the Company entered into a collaboration and license agreement (the “HBM License Agreement”) with HBM Alpha Therapeutics, Inc. (“HBM”). Under the terms of the HBM License Agreement, HBM granted the Company a limited exclusivity, royalty bearing, and sublicensable license to certain technology, patent rights, manufacturing rights, know-how, and proprietary materials relating to certain compounds developed by HBM.

As consideration, the Company made a one-time upfront payment to HBM of $5.0 million in February 2025. Additionally, in January 2025, the Company issued pre-funded warrants to HBM and its affiliates that in total will be equal to 4.99% of the Company's outstanding common stock as of the date of exercise of such pre-funded warrants. The exercise period for the pre-funded warrants expires in June 2025.

The Company concluded that the rights acquired under the HBM License Agreement have no alternative future use. Therefore, the consideration paid of $5.0 million, along with the initial fair value of the pre-funded warrants issued of $0.7 million (see Note 3 “Fair Value Measurements — Warrant Liability”), was recognized as acquired in-process research and development expense, which is reported as a component of research and development expense for the three months ended March 31, 2025.

The Company is also obligated to pay HBM up to an aggregate of $390.0 million upon the achievement of certain development, regulatory, and sales milestones. In addition, the Company is required to pay to HBM certain mid to high-single digit tiered royalties on aggregate annual net sales of licensed products during the applicable royalty term, subject to certain customary reductions.

The Company may terminate the HBM License Agreement on a licensed product-by-licensed product basis or in its entirety at any time for convenience upon prior written notice provided within a specified period of time. Either the Company or HBM may also terminate the HBM License Agreement (i) in the event the other party shall have materially breached its obligations thereunder and such default shall have continued for a specified period after written notice thereof or (ii) upon the bankruptcy or insolvency of the other party. HBM may terminate the HBM License Agreement upon prior written notice if the Company (i) ceases all development or commercialization activities for a specified period of time, subject to certain exceptions, or (ii) challenges the validity, enforceability or scope of any of the patents licensed by the Company to HBM under the HBM License Agreement, subject to certain conditions.

Subsequent Events	3 Months Ended
Mar. 31, 2025
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events Reduction in Force On April 21, 2025, the board of directors approved a plan to implement a workforce reduction of 55% to prioritize development and potential accelerated approval of tralesinidase alfa enzyme replacement therapy for the treatment of Sanfilippo Syndrome Type B. The workforce reduction was effective immediately, with a termination date of May 2, 2025 for affected individuals. Affected individuals will be offered separation benefits, including severance payments and healthcare coverage assistance. The final costs, charges and expenditures relating to the workforce reduction will not be known until all related activities have been completed. The Company estimates that it will incur approximately $0.9 million in cash charges in connection with the workforce reduction, consisting of expenses related to severance payments and healthcare coverage assistance and related costs. The Company expects that most of these estimated charges will be recorded in the second quarter of 2025 and the execution of the workforce reduction will be completed during the second quarter of 2025. The estimate of the costs, charges and expenditures that the Company expects to incur in connection with the workforce reduction, and the timing thereof, are preliminary estimates based on the Company’s current expectations and are subject to a number of assumptions, and actual amounts and results may differ materially from such estimates. In addition, the Company may incur other costs, charges, expenditures, impairments and other impacts not currently contemplated due to unanticipated events that may occur, including in connection with the implementation of the workforce reduction. Nasdaq Delisting As previously reported, on April 26, 2024, the Company received a written notification from the Listing Qualifications Staff of Nasdaq notifying the Company that because the closing bid price for the Company’s common stock had fallen below $1.00 per share for 30 consecutive business days, it no longer complied with the minimum bid price requirement for continued listing under Nasdaq Listing Rule 5450(a)(1) (the “Minimum Bid Price Requirement”). Also as previously reported, on October 24, 2024, the Company received an additional notification from the Listing Qualifications Staff of Nasdaq notifying the Company that the staff had approved the Company’s application to list its stock on the Nasdaq Capital Market, that the Company’s securities would be transferred to the Nasdaq Capital Market at the opening of business on October 28, 2024, and that the Company would be eligible for an additional 180 calendar day period, or until April 21, 2025, to regain compliance with the Minimum Bid Price Requirement. On April 22, 2025, the Company received a written notification (the “Delisting Notice”) from Nasdaq that as a result of the Company’s ongoing failure to comply with the Minimum Bid Price Requirement, the Company’s common stock will be delisted from Nasdaq and trading in the Company’s stock will be suspended at the open of trading on April 29, 2025. In connection with the delisting and suspension, the Company expects that Nasdaq will file a Form 25-NSE with the Securities and Exchange Commission, which will remove the Company’s securities from listing and registration on Nasdaq. The Company has appealed Nasdaq’s determination to its Hearings Panel pursuant to the procedures set forth in the Nasdaq Listing Rule 5800 Series. However, pursuant to Nasdaq Listing Rule 5815(a)(1)(B)(ii)(d), a timely request for a hearing will not stay the trading suspension of the Company’s common stock as the Company was afforded the second 180 days compliance period described in Nasdaq Listing Rule 5810(c)(3)(A)(ii) and failed to regain compliance with the Minimum Bid Price Requirement during such period. As a result of the suspension in trading and expected delisting, the Company’s common stock began trading publicly on the over-the-counter market on April 29, 2025 under its existing symbol “SPRB”. The Company is diligently working to regain compliance with all applicable requirements for continued listing on Nasdaq, including by seeking stockholder approval, at the Company’s upcoming 2025 Annual Meeting of Stockholders, to effect a reverse stock split of the Company’s common stock with a ratio in the range between and including 1-for-5 and 1-for-30, with such ratio to be determined by the Board. The Company intends to submit a plan to regain compliance to that effect to the Hearings Panel as part of the hearing process; however, there can be no assurances that the Hearings Panel will grant any request for continued listing or that the Company will be able to regain compliance with the applicable listing criteria within the period of time that may be granted by the Hearings Panel.

Subsequent Events

3 Months Ended

Mar. 31, 2025

Subsequent Events [Abstract]

Subsequent Events

12. Subsequent Events

Reduction in Force

On April 21, 2025, the board of directors approved a plan to implement a workforce reduction of 55% to prioritize development and potential accelerated approval of tralesinidase alfa enzyme replacement therapy for the treatment of Sanfilippo Syndrome Type B. The workforce reduction was effective immediately, with a termination date of May 2, 2025 for affected individuals. Affected individuals will be offered separation benefits, including severance payments and healthcare coverage assistance.

The final costs, charges and expenditures relating to the workforce reduction will not be known until all related activities have been completed. The Company estimates that it will incur approximately $0.9 million in cash charges in connection with the workforce reduction, consisting of expenses related to severance payments and healthcare coverage assistance and related costs. The Company expects that most of these estimated charges will be recorded in the second quarter of 2025 and the execution of the workforce reduction will be completed during the second quarter of 2025.

The estimate of the costs, charges and expenditures that the Company expects to incur in connection with the workforce reduction, and the timing thereof, are preliminary estimates based on the Company’s current expectations and are subject to a number of assumptions, and actual amounts and results may differ materially from such estimates. In addition, the Company may incur other costs, charges, expenditures, impairments and other impacts not currently contemplated due to unanticipated events that may occur, including in connection with the implementation of the workforce reduction.

Nasdaq Delisting

As previously reported, on April 26, 2024, the Company received a written notification from the Listing Qualifications Staff of Nasdaq notifying the Company that because the closing bid price for the Company’s common stock had fallen below $1.00 per share for 30 consecutive business days, it no longer complied with the minimum bid price requirement for continued listing under Nasdaq Listing Rule 5450(a)(1) (the “Minimum Bid Price Requirement”). Also as previously reported, on October 24, 2024, the Company received an additional notification from the Listing Qualifications Staff of Nasdaq notifying the Company that the staff had approved the Company’s application to list its stock on the Nasdaq Capital Market, that the Company’s securities would be transferred to the Nasdaq Capital Market at the opening of business on October 28, 2024, and that the Company would be eligible for an additional 180 calendar day period, or until April 21, 2025, to regain compliance with the Minimum Bid Price Requirement.

On April 22, 2025, the Company received a written notification (the “Delisting Notice”) from Nasdaq that as a result of the Company’s ongoing failure to comply with the Minimum Bid Price Requirement, the Company’s common stock will be delisted from Nasdaq and trading in the Company’s stock will be suspended at the open of trading on April 29, 2025. In connection with the

delisting and suspension, the Company expects that Nasdaq will file a Form 25-NSE with the Securities and Exchange Commission, which will remove the Company’s securities from listing and registration on Nasdaq.

The Company has appealed Nasdaq’s determination to its Hearings Panel pursuant to the procedures set forth in the Nasdaq Listing Rule 5800 Series. However, pursuant to Nasdaq Listing Rule 5815(a)(1)(B)(ii)(d), a timely request for a hearing will not stay the trading suspension of the Company’s common stock as the Company was afforded the second 180 days compliance period described in Nasdaq Listing Rule 5810(c)(3)(A)(ii) and failed to regain compliance with the Minimum Bid Price Requirement during such period.

As a result of the suspension in trading and expected delisting, the Company’s common stock began trading publicly on the over-the-counter market on April 29, 2025 under its existing symbol “SPRB”. The Company is diligently working to regain compliance with all applicable requirements for continued listing on Nasdaq, including by seeking stockholder approval, at the Company’s upcoming 2025 Annual Meeting of Stockholders, to effect a reverse stock split of the Company’s common stock with a ratio in the range between and including 1-for-5 and 1-for-30, with such ratio to be determined by the Board. The Company intends to submit a plan to regain compliance to that effect to the Hearings Panel as part of the hearing process; however, there can be no assurances that the Hearings Panel will grant any request for continued listing or that the Company will be able to regain compliance with the applicable listing criteria within the period of time that may be granted by the Hearings Panel.

Leases - Additional Information (Details) - South San Francisco, California - ft²	1 Months Ended	3 Months Ended
	Dec. 31, 2022	Mar. 31, 2025
Lessee, Lease, Description [Line Items]
Area of office space	6,500
Operating lease commencement date	2022-12
Operating lease termination date	2028-02
Operating Leases, option to renew lease term description		The Company has an option to extend the lease term of the South San Francisco Lease for an additional three years which has not been included in the lease term as it is not reasonably certain that the Company will exercise this option.
Operating leases, renew lease term	3 years

Net Loss Per Share - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	18,499,971	20,701,707
Shares subject to outstanding common stock warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	12,687,000	12,687,000
Shares subject to outstanding common stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	3,284,576	3,869,873
Shares subject to outstanding RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	2,279,435	4,037,200
Estimated shares issuable under the 2020 Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	248,960	107,634

Organization and Principal Activities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents, and short-term investments	$ 25,600
Net Income (Loss)	(14,041)	$ (11,625)
Cash in operations	12,700
Accumulated deficit	$ (264,309)		$ (250,268)

- 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 accumulated undistributed earnings (deficit).

+ References + Details

Fair Value Measurements

3 Months Ended

Mar. 31, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value.

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

Level 1 — Quoted prices in active markets for identical assets and liabilities;

Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company classifies money market funds as Level 1 instruments as the Company uses quoted prices in active markets for identical assets to determine the fair value. The Company classified its warrant liability as a Level 3 instrument as it is valued using the Black-Scholes option pricing model.

The following table summarizes the Company's financial assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	March 31, 2025
	Total		Level 1		Level 2		Level 3
Financial assets:
Cash equivalents:
Money market funds	$	24,627	$	24,627	$	—	$	—
Total	$	24,627	$	24,627	$	—	$	—
Financial liabilities:
Warrant liability	$	590	$	—	$	—	$	590
Total	$	590	$	—	$	—	$	590


	December 31, 2024
	Total		Level 1		Level 2		Level 3
Financial assets:
Cash equivalents:
Money market funds	$	37,802	$	37,802	$	—	$	—
Total	$	37,802	$	37,802	$	—	$	—

The Company did not have any financial liabilities recorded at fair value as of December 31, 2024.

Warrant Liability

In January 2025, the Company issued pre-funded warrants that in total will be equal to 4.99% of the Company's outstanding common stock as of the date of exercise of such pre-funded warrants. See Note 7 “License and Purchase Agreements — HBM Alpha Therapeutics, Inc.” for further discussion regarding such pre-funded warrants. The exercise period for the pre-funded warrants expires in June 2025.

These pre-funded warrants were accounted for as liabilities under ASC 815-40, Derivatives and Hedging, Contracts in Entity’s Own Equity (“ASC 815-40”), as these pre-funded warrants provided for a settlement provision that do not meet the requirements of the indexation guidance under ASC 815-40. These pre-funded warrants are recorded at fair value as a liability and are included in accrued expenses and other current liabilities on the condensed balance sheets. The change in fair value of the warrant liability is included in interest and other income, net on the condensed statements of operations and comprehensive loss.

The pre-funded warrants were measured using a Black-Scholes option pricing model with the following inputs as of issuance and March 31, 2025:


	Grant Date			March 31, 2025
Exercise price	$	0.01		$	0.01
Expected term (in years)		0.5			0.3
Risk-free interest rate		4.3	%		4.2	%
Expected dividend rate		0.0	%		0.0	%
Expected stock price volatility		65.8	%		43.2	%

The following table provides a roll forward of the aggregate fair value of the Company’s warrant liability (in thousands):


	Warrant Liability
Fair value as of December 31, 2024	$	—
Grant date fair value		748
Change in fair value		(158	)
Fair value as of March 31, 2025	$	590

Term Loan

The estimated fair value of the term loan was $1.6 million and $2.0 million as of March 31, 2025 and December 31, 2024, respectively, and was based on market observable interest rates, a Level 2 input.

- 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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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-Name Accounting Standards Codification
-Section 55
-Paragraph 107
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+ Details

Related Party Transactions - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($)
Related Party Transaction [Line Items]
Accrued compensation expense	$ 0.1
Research and Development
Related Party Transaction [Line Items]
Stock-based compensation expense	$ 0.3

Term Loan - Additional Information (Details) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended
	Nov. 30, 2020 shares	Sep. 30, 2019 USD ($) $ / shares shares	Mar. 31, 2025 USD ($) Installment	Dec. 31, 2024	Dec. 31, 2022 USD ($)
Debt Instrument [Line Items]
Aggregate principal amount			$ 1,402
Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Aggregate principal amount		$ 4,500
Amount of total debt available			$ 30,000
Interest rate of term loan			8.00%	8.00%
Debt instrument, maturity date			Jan. 01, 2026
Number of monthly installments \| Installment			37
Carrying value of the Term Loan			$ 1,300
Unamortized debt discount and issuance costs			7
Term Loan \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Number of shares issuable upon the exercise of warrant \| shares		49,609
Warrants exercise price \| $ / shares		$ 1.44
Estimated fair value of the warrant		$ 100
Term Loan \| Common Stock \| Silicon Valley Bank \| Warrant
Debt Instrument [Line Items]
Net exercised of common stock \| shares	46,358
First Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the first tranche			20,000
End of term payment, amount			300
Debt issuance costs			1,400
Second Tranche Term Loan
Debt Instrument [Line Items]
Commitments					$ 10,000
Second Tranche Term Loan \| Silicon Valley Bank
Debt Instrument [Line Items]
Amount of debt available under the second tranche			$ 10,000
Debt instrument, maturity date			Dec. 31, 2022

Fair Value Measurements - Schedule of Aggregate Fair Value of Warrant Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair value as of December 31, 2024	$ 0
Grant date fair value	748
Change in fair value	(158)	$ 0
Fair value as of March 31, 2025	$ 590

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2025	May 01, 2025
Cover [Abstract]
Entity Registrant Name	Spruce Biosciences, Inc.
Entity Central Index Key	0001683553
Document Type	10-Q
Document Period End Date	Mar. 31, 2025
Trading Symbol	SPRB
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		42,231,285
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity File Number	001-39594
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-2154263
Entity Address, Address Line One	611 Gateway Boulevard
Entity Address, Address Line Two	Suite 740
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	655-4168
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share

License and Purchase Agreements - Additional Information (Details) - USD ($)		1 Months Ended			3 Months Ended		12 Months Ended
	Jan. 31, 2025	Feb. 28, 2025	Nov. 30, 2024	Apr. 30, 2023	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2016
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential Additional Cash Receipt					$ 65,000,000
Research and development					10,837,000	$ 10,317,000
Collaboration revenue					0	2,002,000
Accrued expenses and other current liabilities					12,442,000		$ 12,329,000
Kaken License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payments				$ 15,000,000	15,000,000
Allievex Purchase Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Consideration paid			$ 5,000,000
Consideration assumed as certain liabilities					11,700,000
Contingent consideration paid					6,000,000
Consideration assumed as accrued expenses and other current liabilities					5,700,000
Estimated receivable					1,900,000
Transaction costs					300,000
Aggregate net acquisition cost					15,100
Sales milestones					100,000,000
Allievex Purchase Agreement \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development and regulatory milestones					88,000
Allievex Purchase Agreement \| Maximum \| MPSIIIB
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development and regulatory milestones					25,500,000
Twist License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Consideration paid		$ 500,000
Sales milestones					$ 125,000,000
Research term					The Company can extend the research term by an additional six months by making an extension payment of $0.5 million.
Extension payment					$ 500,000
Exercise payment					$ 1,500,000
Research term, expiration date					Jun. 30, 2025
Payments to acquire in process research and development							$ 500,000
Regulatory milestone					$ 5,000,000
HBM Alpha Therapeutics, Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payments		$ 5,000,000
Development and regulatory milestones					390,000,000
Payments to acquire in process research and development					5,000,000
Fair value of pre-funded warrants issued					700,000
Pre-funded warrants, expiration period	Jun. 30, 2025
Eli Lilly And Company [Member] \| Lilly License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential Additional Payment					$ 23,000,000
Research and development arrangement, costs incurred						$ 0
Research and development								$ 800,000

Organization and Principal Activities

3 Months Ended

Mar. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Principal Activities

1. Organization and Principal Activities

Description of Business

Spruce Biosciences, Inc. (the “Company”) is a late-stage biopharmaceutical company focused on developing and commercializing novel therapies for neurological disorders with significant unmet medical need. The Company is located in South San Francisco, California and was incorporated in the state of Delaware in April 2016.

Liquidity and Capital Resources

The Company has incurred significant losses and negative cash flows from operations. During the three months ended March 31, 2025, the Company incurred a net loss of $14.0 million and used $12.7 million of cash in operations. As of March 31, 2025, the Company had an accumulated deficit of $264.3 million and does not expect positive cash flows from operations in the foreseeable future. The Company has funded its operations primarily through the issuance and sale of equity securities, debt and collaboration revenue.

The accompanying financial statements have been prepared assuming the Company will continue as a going concern, which assumes the realization of assets and satisfaction of liabilities and commitments in the normal course of business. Without alternative financing or proceeds from other strategic alternatives, the Company believes that based on its current operating plan, its cash and cash equivalents of $25.6 million as of March 31, 2025 will be insufficient to fund its planned operations and debt obligations for at least 12 months following the issuance date of these financial statements. The Company’s ability to continue as a going concern will require the Company to raise additional capital to fund the Company's operations and there can be no assurance that additional financing will be available to the Company or that such financing, if available, will be available on terms acceptable to the Company. Accordingly, there is substantial doubt about the Company’s ability to continue as a going concern for at least 12 months following the issuance date of these financial statements.

In order to meet these additional cash requirements, the Company may seek to out-license rights to develop and commercialize its investigational product candidates or sell additional equity or issue debt, convertible debt or other securities that may result in dilution to its stockholders. If the Company raises additional funds through the issuance of debt or convertible debt securities, these securities could have rights senior to those of its shares of common stock and could contain covenants that restrict its operations. There can be no assurance that the Company will be able to obtain additional equity or debt financing on terms acceptable to it, if at all. Additional debt financing, if available, would result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions such as incurring debt, making capital expenditures or declaring dividends. The Company’s failure to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on its business, results of operations, and financial condition.

Subsequent Events - Additional Information (Details) $ in Millions	Apr. 29, 2025	Apr. 22, 2025	Apr. 21, 2025 USD ($)	Oct. 24, 2024 Days	Apr. 26, 2024 Days
Subsequent Event [Line Items]
Number of consecutive business days					30
Number of additional days				180
Subsequent Event
Subsequent Event [Line Items]
Percentage of reduction in workforce			55.00%
Termination date			May 02, 2025
Cash charges \| $			$ 0.9
Trading suspended date		Apr. 29, 2025
Subsequent Event \| Maximum
Subsequent Event [Line Items]
Reverse stock split	1-for-30
Subsequent Event \| Minimum
Subsequent Event [Line Items]
Reverse stock split	1-for-5

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	Jan. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of term loan		$ 1,600	$ 2,000
Liabilities fair value			$ 0
Warrant liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Pre-funded warrants, expiration period	Jun. 30, 2025

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

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-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
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+ Details

Term Loan - Schedule of Future Principal Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Debt Disclosure [Abstract]
2025 (remaining 9 months)	$ 1,266
2026	136
Total	1,402
Less: interest	(50)
Less: unamortized debt issuance costs	(7)
Term loan, current portion	$ 1,345	$ 1,622

- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References + Details

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Capital Structure - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2025	Dec. 31, 2024
Class Of Stock [Line Items]
Shares reserved for future issuance	26,019,684	21,378,467
Shares available for future issuance under 2020 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	1,349,079	926,767
Common Stock Warrants, issued and outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	14,794,341	12,687,000
Stock Options, Issued and Outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	3,284,576	3,523,655
Restricted stock units, issued and outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	2,279,435	2,239,710
Shares available for future issuance under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	4,312,253	2,001,335

- 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.

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+ Details

Fair Value Measurements - Schedule of Pre-funded Warrants Measured Using Black-Scholes Option Pricing Model (Details) - Pre Funded Warrants	Mar. 31, 2025 shares	Jan. 31, 2025 shares
Exercise price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Pre-funded warrants	0.01	0.01
Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Pre-funded warrants, Term	3 months 18 days	6 months
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Pre-funded warrants	0.042	0.043
Expected dividend rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Pre-funded warrants	0	0
Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Pre-funded warrants	0.432	0.658

CONDENSED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	42,231,285	42,231,285
Common stock, shares outstanding	42,231,285	42,231,285

Balance Sheet Components

3 Months Ended

Mar. 31, 2025

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

4. Balance Sheet Components

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2025		2024
Accrued research and development expenses	$	9,254	$	10,635
Accrued general and administrative expenses		1,086		529
Accrued compensation and benefits		932		882
Warrant liability		590		—
Accrued final payment on term loan		289		—
Lease liabilities, current portion		291		283
Total accrued expenses and other current liabilities	$	12,442	$	12,329

Accrued research and development expenses were primarily related to the Allievex asset purchase. See Note 7 “License and Purchase Agreements — Allievex Corporation” for further information regarding such asset purchase.

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2025

Fair Value Disclosures [Abstract]

Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table summarizes the Company's financial assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	March 31, 2025
	Total		Level 1		Level 2		Level 3
Financial assets:
Cash equivalents:
Money market funds	$	24,627	$	24,627	$	—	$	—
Total	$	24,627	$	24,627	$	—	$	—
Financial liabilities:
Warrant liability	$	590	$	—	$	—	$	590
Total	$	590	$	—	$	—	$	590


	December 31, 2024
	Total		Level 1		Level 2		Level 3
Financial assets:
Cash equivalents:
Money market funds	$	37,802	$	37,802	$	—	$	—
Total	$	37,802	$	37,802	$	—	$	—

Schedule of Pre-funded Warrants Measured Using Black-Scholes Option Pricing Model

The pre-funded warrants were measured using a Black-Scholes option pricing model with the following inputs as of issuance and March 31, 2025:


	Grant Date			March 31, 2025
Exercise price	$	0.01		$	0.01
Expected term (in years)		0.5			0.3
Risk-free interest rate		4.3	%		4.2	%
Expected dividend rate		0.0	%		0.0	%
Expected stock price volatility		65.8	%		43.2	%

Schedule of Aggregate Fair Value of Warrant Liability

The following table provides a roll forward of the aggregate fair value of the Company’s warrant liability (in thousands):


	Warrant Liability
Fair value as of December 31, 2024	$	—
Grant date fair value		748
Change in fair value		(158	)
Fair value as of March 31, 2025	$	590

CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Balance at Dec. 31, 2023	$ 76,509	$ 4	$ 273,737	$ (197,232)
Balance, Shares at Dec. 31, 2023		41,029,832
Exercise of common stock options	180		180
Exercise of common stock options, Shares		120,328
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings	(2)		(2)
Issuance of common stock related to vesting of restricted stock units, net of tax withholdings, shares		4,639
Stock-based compensation	1,562		1,562
Net Income (Loss)	(11,625)			(11,625)
Balance at Mar. 31, 2024	66,624	$ 4	275,477	(208,857)
Balance, Shares at Mar. 31, 2024		41,154,799
Balance at Dec. 31, 2024	$ 28,821	$ 4	279,085	(250,268)
Balance, Shares at Dec. 31, 2024	42,231,285	42,231,285
Stock-based compensation	$ 544		544
Net Income (Loss)	(14,041)			(14,041)
Balance at Mar. 31, 2025	$ 15,324	$ 4	$ 279,629	$ (264,309)
Balance, Shares at Mar. 31, 2025	42,231,285	42,231,285

- 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://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Stock-Based Compensation Expense - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 544	$ 1,562
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	126	579
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 418	$ 983

Stock-Based Compensation Expense (Tables)

3 Months Ended

Mar. 31, 2025

Share-Based Payment Arrangement [Abstract]

Summary of Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the Company’s condensed statements of operations and comprehensive loss during the three months ended March 31, 2025 and 2024 (in thousands):


	Three Months Ended March 31,
	2025		2024
Research and development	$	126	$	579
General and administrative		418		983
Total stock-based compensation expense	$	544	$	1,562

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2025

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules and regulations, certain notes or other financial information normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed balance sheet as of March 31, 2025, the condensed statements of operations and comprehensive loss for the three months ended March 31, 2025 and 2024, the condensed statement of stockholders’ equity for the three months ended March 31, 2025 and 2024, and the condensed statements of cash flows for the three months ended March 31, 2025 and 2024 are unaudited. The interim condensed financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal, recurring adjustments that are necessary to present fairly the Company’s results for the interim periods presented. The condensed balance sheet as of December 31, 2024 is derived from the Company’s audited financial statements. The results of operations for the three months ended March 31, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025, or for any other future annual or interim period.

These interim condensed financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC on April 15, 2025 (“Annual Report”).

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, revenue recognition, stock-based compensation, and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Risks and Uncertainties

Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements.

The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical success of the Company’s product candidates, ability to obtain regulatory approval of its product candidates, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition, untested manufacturing capabilities, and dependence on key individuals and sole source suppliers.

Global economic and business activities continue to face widespread macroeconomic and geopolitical uncertainties, including global trade disputes, labor shortages, declines in consumer confidence, inflation and monetary supply shifts, recession risks, potential disruptions from the ongoing wars in Ukraine and Israel and related sanctions, declines in economic growth, and uncertainty about economic stability. The Company continues to actively monitor the impact of these macroeconomic and geopolitical factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business.

Concentration of Credit Risk

Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the condensed balance sheets.

Segment Reporting

The Company operates and manages its business as one reportable and operating segment, which is the business of developing and commercializing novel therapies for serious neurological and disorders with significant unmet medical need. The Company’s chief executive officer, who is the chief operating decision maker (“CODM”), reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in the United States of America.

The Company's segment revenue was derived from a collaboration and license agreement with Kaken Pharmaceutical Co, Ltd. (see Note 7 “License and Purchase Agreements — Kaken Pharmaceutical Co, Ltd.”). The CODM assesses performance and decides how to allocate resources based on net loss. Net loss is used to monitor budget versus actual results. The measure of segment revenue, segment net loss and segment expenses is reported on the condensed statements of operations and comprehensive loss. The measure of segment assets is reported on the condensed balance sheets as total assets.

Significant Accounting Policies

There have been no significant changes to the significant accounting policies during the three months ended March 31, 2025, as compared to the significant accounting policies described in the Annual Report.

Emerging Growth Company Status

The Company is an emerging growth company as defined in the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying

with new or revised accounting standards. The Company may take advantage of these exemptions until December 31, 2025, or until the Company is no longer an emerging growth company, whichever is earlier.

Recent Accounting Pronouncements - Not Yet Adopted

In December 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update 2023-09, Income Taxes - Improvements to Income Tax Disclosures (“ASU 2023-09”) requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. ASU 2023-09 does not impact the Company's results of operations, financial condition or cash flows. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company will adopt ASU 2023-09 for the fiscal year ending December 31, 2025. Other than the presentation of additional disaggregated data in the income tax footnote disclosures for annual periods, the Company does not expect the adoption of ASU 2023-09 to have a material impact on its financial statements.

In November 2024, the FASB issued Accounting Standards Update 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (“ASU 2024-03”), which requires disaggregated information about certain income statement expense line items on an annual and interim basis. ASU 2024-03 is effective for annual periods beginning after December 15, 2026 and interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted and can be applied prospectively or retrospectively. The Company is evaluating the impact of the adoption of this standard on the Company’s financial statements and related disclosures.

Summary of Significant Accounting Policies (Additional Information) (Details)	3 Months Ended
	Mar. 31, 2025 Segment
Accounting Policies [Abstract]
Number of reportable segment	1
Number of operating segment	1

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2025

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2025			2024
Numerator:
Net loss	$	(14,041	)	$	(11,625	)
Denominator:
Weighted-average shares of common stock outstanding		43,944,946			41,096,231
Net loss per share, basic and diluted	$	(0.32	)	$	(0.28	)

Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share

Basic net loss per share was the same as diluted net loss per share for all periods as the inclusion of potentially dilutive securities would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations were as follows:


	March 31,
	2025		2024
Shares subject to outstanding common stock warrants		12,687,000		12,687,000
Shares subject to outstanding common stock options		3,284,576		3,869,873
Shares subject to outstanding RSUs		2,279,435		4,037,200
Estimated shares issuable under the 2020 Employee Stock Purchase Plan		248,960		107,634
Total		18,499,971		20,701,707

Leases

3 Months Ended

Mar. 31, 2025

Leases [Abstract]

Leases

5. Leases

The Company leases space under a non-cancelable operating lease, which requires the Company to pay base rent, real estate taxes, insurance, general repairs, and maintenance. In December 2022, the Company entered into a non-cancelable operating lease for approximately 6,500 square feet of office space in South San Francisco, California, which commenced in December 2022 and expires in February 2028 (the “South San Francisco Lease”). The Company has an option to extend the lease term of the South San Francisco Lease for an additional three years which has not been included in the lease term as it is not reasonably certain that the Company will exercise this option.

Stock-Based Compensation Expense - Additional Information (Details) - RSU	3 Months Ended
	Mar. 31, 2025 shares
Share Based Compensation Award Tranche Four
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs outstanding	512,800
Probable of Achievement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted	0

- 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

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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash flows from operating activities
Net loss	$ (14,041)	$ (11,625)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	544	1,562
Depreciation and amortization	6	15
Non-cash lease expense	65	60
Change in fair value of warrant liability	(158)	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	492	(191)
Other assets	0	74
Accounts payable	584	(1,441)
Accrued expenses and other current liabilities	140	(1,354)
Deferred revenue	0	(2,003)
Other liabilities	(359)	(55)
Net cash used in operating activities	(12,727)	(14,958)
Cash flows from financing activities
Proceeds from exercise of common stock options	0	180
Repayment of term loan	(405)	(405)
Payment of offering costs	(6)	0
Tax withholding payments on restricted stock units	0	(2)
Net cash used in financing activities	(411)	(227)
Net decrease in cash, cash equivalents, and restricted cash	(13,138)	(15,185)
Cash, cash equivalents, and restricted cash at beginning of period	38,788	96,374
Cash, cash equivalents, and restricted cash at end of period	25,650	81,189
Reconciliation of cash, cash equivalents, and restricted cash
Cash and cash equivalents	25,615	81,154
Restricted cash, long-term (included in other assets)	35	35
Total cash, cash equivalents and restricted cash	$ 25,650	$ 81,189

Net Loss Per Share

3 Months Ended

Mar. 31, 2025

Earnings Per Share [Abstract]

Net Loss Per Share

10. Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2025			2024
Numerator:
Net loss	$	(14,041	)	$	(11,625	)
Denominator:
Weighted-average shares of common stock outstanding		43,944,946			41,096,231
Net loss per share, basic and diluted	$	(0.32	)	$	(0.28	)


	March 31,
	2025		2024
Shares subject to outstanding common stock warrants		12,687,000		12,687,000
Shares subject to outstanding common stock options		3,284,576		3,869,873
Shares subject to outstanding RSUs		2,279,435		4,037,200
Estimated shares issuable under the 2020 Employee Stock Purchase Plan		248,960		107,634
Total		18,499,971		20,701,707

CONDENSED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 25,615	$ 38,753
Prepaid expenses	2,899	3,177
Other current assets	2,062	2,276
Total current assets	30,576	44,206
Right-of-use assets	869	934
Other assets	204	69
Total assets	31,649	45,209
Current liabilities:
Accounts payable	1,879	1,295
Accrued expenses and other current liabilities	12,442	12,329
Term loan, current portion	1,345	1,622
Total current liabilities	15,666	15,246
Lease liabilities, net of current portion	659	736
Term loan, current portion	0	124
Other liabilities	0	282
Total liabilities	16,325	16,388
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding as of March 31, 2025 and December 31, 2024	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized as of March 31, 2025 and December 31, 2024; 42,231,285 shares issued and outstanding as of March 31, 2025 and December 31, 2024	4	4
Additional paid-in capital	279,629	279,085
Accumulated deficit	(264,309)	(250,268)
Total stockholders' equity	15,324	28,821
Total liabilities and stockholders’ equity	$ 31,649	$ 45,209

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Balance Sheet Related Disclosures [Abstract]
Accrued research and development expenses	$ 9,254	$ 10,635
Accrued general and administrative expenses	1,086	529
Accrued compensation and benefits	932	882
Warrant liability	590	0
Accrued final payment on term loan	289	0
Lease liabilities, current portion	291	283
Total accrued expenses and other current liabilities	$ 12,442	$ 12,329

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Pay vs Performance Disclosure
Net Income (Loss)	$ (14,041)	$ (11,625)

- Definition

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

+ References

+ Details

Capital Structure - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Class Of Stock [Line Items]
Common stock shares authorized	200,000,000	200,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stockholders voting rights	one vote
Common stock dividends declared	$ 0

- 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

+ Details

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure, Total		$ 0
Fair Value Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Total	$ 24,627	37,802
Liabilities, Fair Value Disclosure, Total	590
Fair Value Recurring \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	24,627	37,802
Fair Value Recurring \| Warrant liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	590
Fair Value Recurring \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Total	24,627	37,802
Liabilities, Fair Value Disclosure, Total	0
Fair Value Recurring \| Level 1 \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	24,627	37,802
Fair Value Recurring \| Level 1 \| Warrant liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0
Fair Value Recurring \| Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Total	0	0
Liabilities, Fair Value Disclosure, Total	0
Fair Value Recurring \| Level 2 \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0	0
Fair Value Recurring \| Level 2 \| Warrant liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	0
Fair Value Recurring \| Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Total	0	0
Liabilities, Fair Value Disclosure, Total	590
Fair Value Recurring \| Level 3 \| Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value	0	$ 0
Fair Value Recurring \| Level 3 \| Warrant liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure, Total	$ 590

Stock-Based Compensation Expense

3 Months Ended

Mar. 31, 2025

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation Expense

9. Stock-Based Compensation Expense


	Three Months Ended March 31,
	2025		2024
Research and development	$	126	$	579
General and administrative		418		983
Total stock-based compensation expense	$	544	$	1,562

Restricted Stock Units (“RSUs”)

As of March 31, 2025, the Company had 512,800 RSUs outstanding subject to performance-based vesting conditions, of which none are considered probable of achievement.

Capital Structure

3 Months Ended

Mar. 31, 2025

Equity [Abstract]

Capital Structure

8. Capital Structure

Common Stock

As of March 31, 2025 and December 31, 2024, the Company was authorized to issue 200,000,000 shares of common stock $0.0001 par value per share. Holders of common stock are entitled to dividends if and when declared by the board of directors of the Company. The holder of each share of common stock is entitled to one vote. As of March 31, 2025, no dividends were declared.

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	March 31,		December 31,
	2025		2024
Common stock warrants, issued and outstanding		14,794,341		12,687,000
Stock options, issued and outstanding		3,284,576		3,523,655
Restricted stock units, issued and outstanding		2,279,435		2,239,710
Shares available for future issuance under 2020 Equity Incentive Plan		4,312,253		2,001,335
Shares available for future issuance under 2020 Employee Stock Purchase Plan		1,349,079		926,767
Total shares reserved		26,019,684		21,378,467

- 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
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-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
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-Section 50
-Paragraph 14
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

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/1943274/2147477968/946-235-50-2

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/1943274/2147478448/946-505-50-6

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
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-Publisher FASB
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Paragraph 1
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-Publisher FASB
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Income Statement [Abstract]
Collaboration revenue	$ 0	$ 2,002
Operating expenses:
Research and development	10,837	10,317
General and administrative	3,655	4,318
Total operating expenses	14,492	14,635
Loss from operations	(14,492)	(12,633)
Interest expense	(36)	(97)
Interest and other income, net	487	1,105
Net loss and comprehensive loss	$ (14,041)	$ (11,625)
Net loss per share, basic	$ (0.32)	$ (0.28)
Net loss per share, diluted	$ (0.32)	$ (0.28)
Weighted-average shares of common stock outstanding, basic	43,944,946	41,096,231
Weighted-average shares of common stock outstanding, diluted	43,944,946	41,096,231

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Term Loan (Tables)

3 Months Ended

Mar. 31, 2025

Debt Disclosure [Abstract]

Schedule of Future Principal Payments

As of March 31, 2025, future payments of principal and interest are as follows (in thousands):


Year ending December 31,
2025 (remaining 9 months)		1,266
2026		136
Total	$	1,402
Less: interest		(50	)
Less: unamortized debt issuance costs		(7	)
Term loan, current portion	$	1,345

Term Loan

3 Months Ended

Mar. 31, 2025

Debt Disclosure [Abstract]

Term Loan

6. Term Loan

In September 2019, the Company entered into a Loan and Security Agreement, as subsequently amended (the “Loan Agreement”) with Silicon Valley Bank (“SVB”) providing for a term loan (the “Term Loan”) for an aggregate principal amount of $4.5 million.

In September 2019 and in connection with the Loan Agreement, the Company issued a warrant to purchase up to an aggregate of 49,609 shares of common stock at $1.44 per share. The Company determined the initial fair value of the warrant to be $0.1 million using the Black-Scholes option-pricing model. The fair value of the warrant was recorded to equity and as a debt discount, which was being amortized to interest expense using the effective interest method over the term of the Term Loan. In November 2020, the warrant was net-exercised for 46,358 shares of common stock.

In March 2021, the Company entered into a First Amendment to Loan and Security Agreement (the “First Amendment”), which increased the aggregate principal amount of the Term Loan to $30.0 million, of which $20.0 million was immediately available under the first tranche (“First Tranche”) and $10.0 million was available under the second tranche through December 31, 2022 (“Second Tranche”), subject to the completion of certain clinical or financial milestones. Pursuant to the First Amendment, the Term Loan will mature on January 1, 2026 (the “Maturity Date”).

In May 2022, the Company entered into a Second Amendment to Loan and Security Agreement (the “Second Amendment”), which amended the milestones for the Second Tranche, added a liquidity covenant for the Second Tranche and amended the interest and prepayment terms.

As of March 31, 2025, the carrying value of the Term Loan was $1.3 million, consisting of the outstanding principal under the First Tranche of $1.4 million, less unamortized debt discount and issuance costs of $7 thousand, which are being amortized using the effective interest method over the life of the Term Loan. Commitments available under the Second Tranche of $10.0 million expired on December 31, 2022.

The Loan Agreement provided for monthly cash interest-only payments following the funding date of each respective tranche and continuing thereafter through December 31, 2022. The Term Loan is subject to a floating per annum interest rate equal to the greater of (a) 0.50% above the Prime Rate (as defined in the Loan Agreement) or (b) 3.75%. Following the interest-only period, the outstanding Term Loan balance is payable in (i) 37 consecutive monthly payments after the end of the interest-only period and continuing on the same day of each month thereafter, in amounts that would fully amortize such Term Loan balance, as of the first business day of the first month following the amended interest-only period, over the repayment period, plus (ii) monthly payments of accrued but unpaid interest. As of March 31, 2025 and December 31, 2024, the stated interest rate of the Term Loan was 8.0%.

The final payment is due on the Maturity Date and includes all outstanding principal plus accrued unpaid interest and an end of term payment totaling $0.3 million, which is 6.0% of the original funded principal amount of the First Tranche (the “Supplemental Final Payment”). The Company may prepay amounts outstanding under the Term Loan at any time provided certain notification conditions are met, in which case, all outstanding principal plus accrued and unpaid interest, the Supplemental Final Payment, a prepayment fee of 1% or 2% of the principal amount of the First Tranche, and any bank expenses become due and payable.

The Company is subject to customary affirmative and restrictive covenants under the Loan Agreement. The Company’s obligations under the Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than intellectual property. The Company also agreed not to encumber its intellectual property assets, except as permitted by the Loan Agreement.

The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations under the Loan Agreement and the occurrence of a material adverse

change in its business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the lender would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement. As of March 31, 2025, the Company was in compliance with all covenants under the Loan Agreement and there has been no material adverse change.

As of March 31, 2025, future payments of principal and interest are as follows (in thousands):


Year ending December 31,
2025 (remaining 9 months)		1,266
2026		136
Total	$	1,402
Less: interest		(50	)
Less: unamortized debt issuance costs		(7	)
Term loan, current portion	$	1,345

- 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 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2025
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules and regulations, certain notes or other financial information normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed balance sheet as of March 31, 2025, the condensed statements of operations and comprehensive loss for the three months ended March 31, 2025 and 2024, the condensed statement of stockholders’ equity for the three months ended March 31, 2025 and 2024, and the condensed statements of cash flows for the three months ended March 31, 2025 and 2024 are unaudited. The interim condensed financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal, recurring adjustments that are necessary to present fairly the Company’s results for the interim periods presented. The condensed balance sheet as of December 31, 2024 is derived from the Company’s audited financial statements. The results of operations for the three months ended March 31, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025, or for any other future annual or interim period. These interim condensed financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC on April 15, 2025 (“Annual Report”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, revenue recognition, stock-based compensation, and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the condensed balance sheets.
Segment Reporting	Segment Reporting The Company operates and manages its business as one reportable and operating segment, which is the business of developing and commercializing novel therapies for serious neurological and disorders with significant unmet medical need. The Company’s chief executive officer, who is the chief operating decision maker (“CODM”), reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in the United States of America. The Company's segment revenue was derived from a collaboration and license agreement with Kaken Pharmaceutical Co, Ltd. (see Note 7 “License and Purchase Agreements — Kaken Pharmaceutical Co, Ltd.”). The CODM assesses performance and decides how to allocate resources based on net loss. Net loss is used to monitor budget versus actual results. The measure of segment revenue, segment net loss and segment expenses is reported on the condensed statements of operations and comprehensive loss. The measure of segment assets is reported on the condensed balance sheets as total assets.
Significant Accounting Policies	Significant Accounting Policies There have been no significant changes to the significant accounting policies during the three months ended March 31, 2025, as compared to the significant accounting policies described in the Annual Report.

- Definition

Disclosure of accounting policy for segment reporting.

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+ Details