Note 2. Collaboration Agreements

Alligator Bioscience AB

On July 20, 2017, our wholly owned subsidiary, Aptevo R&D, entered into a collaboration and option agreement (the "Collaboration Agreement") with Alligator Bioscience AB ("Alligator"), pursuant to which Aptevo and Alligator have been collaboratively developing ALG.APV-527, a first-in-class bispecific antibody candidate simultaneously targeting 4-1BB (CD137), a member of the TNFR superfamily of a costimulatory receptor found on activated T cells, and 5T4, a tumor antigen widely overexpressed in a number of different types of cancer.

We assessed the arrangement in accordance with ASC 606 and concluded that the contract counterparty, Alligator, is not a customer. As such the arrangement is not in the scope of ASC 606 and is instead treated as a collaborative agreement under ASC 808 – Collaborative Arrangements ("ASC 808"). In accordance with ASC 808, we concluded that because the Collaboration Agreement is a cost sharing agreement, there is no revenue.

For the six months ended June 30, 2025 and 2024, we recorded approximately $0.2 million and $1.3 million, which represent our 50% cost share, in our research and development expense related to the Collaboration Agreement, respectively.