Collaboration Agreement with GSK	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreement with GSK	5. Collaboration Agreement with GSK On July 1, 2021, the Company entered into a Collaboration and License Agreement with Glaxo Wellcome UK Limited, a subsidiary of GlaxoSmithKline plc (GSK), pursuant to which the Company and GSK collaborate on the global development and commercialization of progranulin-elevating monoclonal antibodies, including latozinemab and nivisnebart (formerly AL101/GSK4527226) (GSK Agreement). The GSK Agreement became effective on August 17, 2021. Under the terms of the GSK Agreement, the Company received $700 million in upfront payments, of which $500 million was received in August 2021 and $200 million was received in January 2022. In addition, the Company may be eligible to receive up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments, subject to successful advancement and commercialization of product candidates in multiple indications under the agreement. In the United States, the Company and GSK will equally share profits and losses from commercialization of product candidates under the agreement. Outside of the United States, the Company will be eligible for double-digit tiered royalties. The Company and GSK will conduct development jointly, with GSK conducting Phase 3 clinical trials for Alzheimer’s disease, Parkinson’s disease and other non-orphan indications. GSK conducted the Phase 2 trial for nivisnebart in Alzheimer’s disease. Development costs will be shared 60% by GSK and 40% by the Company, except that, subject to the GSK Amendment (defined below), the Company will solely bear the development costs of the initial Phase 2 clinical trials under the development plan, and the parties would share manufacturing development costs equally. In May 2023, the Company and GSK amended the GSK Agreement (GSK Amendment). Under the terms of the GSK Amendment, the Company was responsible for funding and sharing in GSK’s and the Company’s development costs up to $140.5 million for the conduct of the initial Phase 2 trial for nivisnebart in Alzheimer’s disease. The GSK Amendment was determined to be a contract modification to the GSK Agreement. The expected cost reimbursement to GSK was accounted for as a refund liability, which reduced the transaction price for the GSK Agreement. During the three months ended September 30, 2023, as a result of the planned closure of the latozinemab Phase 2 trial and concurrent agreement by the Company to cost-share additional research and development, the Company determined there was a modification of the GSK Agreement, resulting in a decrease of the scope of the performance obligation associated with the latozinemab FTD-C9orf72 Phase 2 trial and an increase in the amount of research and development cost-shared by the Company in future periods. The impact of this additional cost share was accounted for as a refund liability, which reduced the transaction price for the GSK Agreement. The transaction price at inception included fixed consideration consisting of the upfront payments of $700 million. The transaction price as of March 31, 2026 was $568.0 million due to the estimated refund liabilities created from the contract modifications. The remaining estimated refund liabilities to collaboration partner as of March 31, 2026 and December 31, 2025 was zero and $11.4 million, respectively. All potential future milestones and other payments were considered constrained at the inception of the GSK Agreement and as of March 31, 2026, since the Company could not conclude it was probable that a significant reversal in the amount of revenue recognized would not occur. Collaboration revenue under the GSK Agreement during the three months ended March 31, 2026 and 2025 was $1.0 million and $3.7 million, respectively, the entire amount of which was included in deferred revenue at the beginning of the respective period. The deferred revenue related to the GSK Agreement was $169.6 million and $171.2 million as of March 31, 2026 and December 31, 2025, respectively. The deferred revenue is expected to be recognized over the research and development period of the programs through the completion of initial Phase 2 clinical trials. Costs associated with co-development activities performed under the agreement are included in research and development expenses in the condensed consolidated statements of operations, with any reimbursement of costs by GSK reflected as a reduction of such expenses. For the three months ended March 31, 2026 and 2025, the Company recognized a reduction of research and development expense of $1.8 million and $4.3 million, respectively, under the GSK Agreement.

Collaboration Agreement with GSK

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

5. Collaboration Agreement with GSK

On July 1, 2021, the Company entered into a Collaboration and License Agreement with Glaxo Wellcome UK Limited, a subsidiary of GlaxoSmithKline plc (GSK), pursuant to which the Company and GSK collaborate on the global development and commercialization of progranulin-elevating monoclonal antibodies, including latozinemab and nivisnebart (formerly AL101/GSK4527226) (GSK Agreement). The GSK Agreement became effective on August 17, 2021.

Under the terms of the GSK Agreement, the Company received $700 million in upfront payments, of which $500 million was received in August 2021 and $200 million was received in January 2022. In addition, the Company may be eligible to receive up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments, subject to successful advancement and commercialization of product candidates in multiple indications under the agreement. In the United States, the Company and GSK will equally share profits and losses from commercialization of product candidates under the agreement. Outside of the United States, the Company will be eligible for double-digit tiered royalties.

The Company and GSK will conduct development jointly, with GSK conducting Phase 3 clinical trials for Alzheimer’s disease, Parkinson’s disease and other non-orphan indications. GSK conducted the Phase 2 trial for nivisnebart in Alzheimer’s disease. Development costs will be shared 60% by GSK and 40% by the Company, except that, subject to the GSK Amendment (defined below), the Company will solely bear the development costs of the initial Phase 2 clinical trials under the development plan, and the parties would share manufacturing development costs equally.

In May 2023, the Company and GSK amended the GSK Agreement (GSK Amendment). Under the terms of the GSK Amendment, the Company was responsible for funding and sharing in GSK’s and the Company’s development costs up to $140.5 million for the conduct of the initial Phase 2 trial for nivisnebart in Alzheimer’s disease. The GSK Amendment was determined to be a contract modification to the GSK Agreement. The expected cost reimbursement to GSK was accounted for as a refund liability, which reduced the transaction price for the GSK Agreement.

During the three months ended September 30, 2023, as a result of the planned closure of the latozinemab Phase 2 trial and concurrent agreement by the Company to cost-share additional research and development, the Company

determined there was a modification of the GSK Agreement, resulting in a decrease of the scope of the performance obligation associated with the latozinemab FTD-C9orf72 Phase 2 trial and an increase in the amount of research and development cost-shared by the Company in future periods. The impact of this additional cost share was accounted for as a refund liability, which reduced the transaction price for the GSK Agreement.

The transaction price at inception included fixed consideration consisting of the upfront payments of $700 million. The transaction price as of March 31, 2026 was $568.0 million due to the estimated refund liabilities created from the contract modifications. The remaining estimated refund liabilities to collaboration partner as of March 31, 2026 and December 31, 2025 was zero and $11.4 million, respectively. All potential future milestones and other payments were considered constrained at the inception of the GSK Agreement and as of March 31, 2026, since the Company could not conclude it was probable that a significant reversal in the amount of revenue recognized would not occur.

Collaboration revenue under the GSK Agreement during the three months ended March 31, 2026 and 2025 was $1.0 million and $3.7 million, respectively, the entire amount of which was included in deferred revenue at the beginning of the respective period. The deferred revenue related to the GSK Agreement was $169.6 million and $171.2 million as of March 31, 2026 and December 31, 2025, respectively. The deferred revenue is expected to be recognized over the research and development period of the programs through the completion of initial Phase 2 clinical trials.

Costs associated with co-development activities performed under the agreement are included in research and development expenses in the condensed consolidated statements of operations, with any reimbursement of costs by GSK reflected as a reduction of such expenses. For the three months ended March 31, 2026 and 2025, the Company recognized a reduction of research and development expense of $1.8 million and $4.3 million, respectively, under the GSK Agreement.