On November 4, 2025 Merck (NYSE: MRK), known as MSD outside of the United States and Canada, reported that the company, through a subsidiary (Prometheus BioSciences), has reached an agreement with Dr. Falk Pharma GmbH (Falk) to discontinue an existing contract concerning co-development and co-commercialization rights in certain territories for MK-8690 (formerly PRA-052), and for Merck to assume full responsibility for the development program going forward. MK-8690 is an investigational anti-CD30 ligand monoclonal antibody being evaluated by Merck in an early-stage clinical trial.

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Under the terms of the agreement, Prometheus BioSciences (Prometheus) and Falk have discontinued their collaboration based on their existing co-development contract resulting in Prometheus having secured global rights to MK-8690. In exchange, Falk will receive a $150 million upfront payment and is eligible to receive a payment associated with a development milestone as well as royalties on sales in certain territories. The original contract between Falk and Prometheus was signed in 2020. Merck subsequently acquired Prometheus in 2023.

As a result of the transaction with Falk, Merck will record a pre-tax charge to research and development expenses of $150 million, or approximately $0.05 per share, in both its GAAP and non-GAAP fourth quarter results.

(Press release, Merck & Co, NOV 4, 2025, View Source [SID1234659362])