rinvatercept (KER-065)

Sept. 28, 2026: Keros Therapeutics (NASDAQ: KROS) announced the first patient was dosed in a Phase 2 trial of rinvatercept for Duchenne muscular dystrophy (DMD). The study (NCT07704099) is an open-label, multi-cohort basket trial in late-ambulatory and early non-ambulatory DMD patients. The primary objective is safety and tolerability; key secondary objectives are pharmacokinetics, anti-drug antibodies, body composition, and functional outcomes across skeletal muscle, motor, cardiac, and pulmonary measures.

Keros said rinvatercept is a ligand trap targeting myostatin and activin A signaling and is intended to affect muscle and bone biology. The company also stated rinvatercept is being developed for amyotrophic lateral sclerosis (ALS), while elritercept is its most advanced product candidate for cytopenias, including anemia and thrombocytopenia, in myelodysplastic syndromes and myelofibrosis.

The release identifies first-patient dosing as a development milestone and says initial Phase 2 DMD data are expected, but does not provide a timing date.