Collaboration Agreement with GSK	6 Months Ended
Jun. 30, 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. The Company and GSK discontinued developing latozinemab and nivisnebart in frontotemporal dementia due to a GRN mutation (FTD-GRN) and Alzheimer’s disease (AD), respectively, following the INFRONT-3 Phase 3 clinical trial readout in October 2025 and the PROGRESS-AD Phase 2 clinical trial interim analysis in April 2026 for those product candidates. On July 6, 2026, GSK provided written notice to the Company terminating the GSK Agreement (“Notice”). Under the terms of the GSK Agreement, the termination will be effective 180 days from the Notice, or January 2, 2027. 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. The Company had been eligible for but did not achieve up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments; an equal share of profits and losses in the United States; and tiered royalties outside the United States. The Company and GSK jointly conducted certain development activities under the GSK Agreement and shared development costs 60% by GSK and 40% by the Company, except that, subject to the GSK Amendment (defined below), the Company solely bore the development costs of initial Phase 2 clinical trials. 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 June 30, 2026 was $564.0 million due to the estimated refund liabilities created from the contract modifications. The remaining estimated refund liabilities to collaboration partner as of June 30, 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 June 30, 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 and six months ended June 30, 2026 was $3.3 million and $4.4 million, respectively, the entire amount of which was included in deferred revenue at the beginning of the respective period. For the three and six months ended June 30, 2025, collaboration revenue under the GSK Agreement was $7.9 million and $11.5 million, respectively. The deferred revenue related to the GSK Agreement was $162.9 million and $171.2 million as of June 30, 2026 and December 31, 2025, respectively. As of June 30, 2026, the Company expected to recognize this deferred revenue over the research and development period of the programs through the completion of initial Phase 2 clinical trials, or earlier upon extinguishment of the related performance obligations. 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 June 30, 2026 , the Company recognized an increase of $0.3 million of research and development expense, and for the six months ended June 30, 2026, the Company recognized a reduction of research and development expense of $1.5 million, under the GSK Agreement. For the three and six months ended June 30, 2025, the Company recognized a reduction of research and development expense of $6.1 million and $10.4 million, respectively, under the GSK Agreement.

Collaboration Agreement with GSK

6 Months Ended

Jun. 30, 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. The Company and GSK discontinued developing latozinemab and nivisnebart in frontotemporal dementia due to a GRN mutation (FTD-GRN) and Alzheimer’s disease (AD), respectively, following the INFRONT-3 Phase 3 clinical trial readout in October 2025 and the PROGRESS-AD Phase 2 clinical trial interim analysis in April 2026 for those product candidates. On July 6, 2026, GSK provided written notice to the Company terminating the GSK Agreement (“Notice”). Under the terms of the GSK Agreement, the termination will be effective 180 days from the Notice, or January 2, 2027.

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. The Company had been eligible for but did not achieve up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments; an equal share of profits and losses in the United States; and tiered royalties outside the United States. The Company and GSK jointly conducted certain development activities under the GSK Agreement and shared development costs 60% by GSK and 40% by the Company, except that, subject to the GSK Amendment (defined below), the Company solely bore the development costs of initial Phase 2 clinical trials.

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 June 30, 2026 was $564.0 million due to the estimated refund liabilities created from the contract modifications. The remaining estimated refund liabilities to collaboration partner as of June 30, 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 June 30, 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 and six months ended June 30, 2026 was $3.3 million and $4.4 million, respectively, the entire amount of which was included in deferred revenue at the beginning of the respective period. For the three and six months ended June 30, 2025, collaboration revenue under the GSK Agreement was $7.9 million and $11.5 million, respectively. The deferred revenue related to the GSK Agreement was $162.9 million and $171.2 million as of June 30, 2026 and December 31, 2025, respectively. As of June 30, 2026, the Company expected to recognize this deferred revenue over the research and development period of the programs through the completion of initial Phase 2 clinical trials, or earlier upon extinguishment of the related performance obligations.

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 June 30, 2026 , the Company recognized an increase of $0.3 million of research and development expense, and for the six months ended June 30, 2026, the Company recognized a reduction of research and development expense of $1.5 million, under the GSK Agreement. For the three and six months ended June 30, 2025, the Company recognized a reduction of research and development expense of $6.1 million and $10.4 million, respectively, under the GSK Agreement.