Merck Gains Full Global Rights To MK-8690 Following Agreement With Dr. Falk Pharma
Merck secures full global rights to MK-8690 after ending co-development with Falk, recording a $150 million charge in Q4.
Breaking News
Nov 05, 2025
Vaibhavi M.

Merck (NYSE: MRK), known as MSD outside the U.S. and Canada, announced that through its subsidiary Prometheus BioSciences, it has reached an agreement with Dr. Falk Pharma GmbH (Falk) to end their existing contract for co-development and co-commercialization of MK-8690 (formerly PRA-052). Following the termination, Merck will take full ownership and responsibility for the ongoing development of MK-8690, an investigational anti-CD30 ligand monoclonal antibody currently being studied in early-stage clinical trials.
Under the new agreement, Prometheus BioSciences now holds exclusive global rights to MK-8690. In return, Falk will receive a $150 million upfront payment and remains eligible for a future development milestone payment and royalties from sales in certain regions. The original collaboration between Prometheus and Falk began in 2020, before Merck acquired Prometheus in 2023 to strengthen its immunology and precision medicine capabilities.
Merck stated that the termination of the agreement will result in a pre-tax R&D expense of $150 million, equating to approximately $0.05 per share, which will be reflected in the company’s fourth-quarter GAAP and non-GAAP results. This strategic move consolidates Merck’s control over the MK-8690 program as it advances its early-stage pipeline.
