Merck ends Sutro partnership on IL-2 agonist MK-1484 amid routine pipeline prioritization

Merck announced it is discontinuing development of MK-1484, an interleukin-2 agonist created in partnership with Sutro Biopharma.

The drug entered clinical testing in 2022 as a monotherapy and in combination with Merck’s PD-1 antibody Keytruda for patients with advanced solid tumors, with plans to finish the study this year and move to a phase 2 dose-finding trial.

Merck said the termination is part of a routine pipeline prioritization and did not provide further details on the decision or its impact on future IL-2 strategies.

This follows Merck’s earlier abandonment of an autoimmune-focused IL-2 mutein acquired from Pandion Therapeutics, leaving the company without any IL-2 assets listed in its pipeline.