Keros Therapeutics dosed the first patient in its Phase 2 trial of rinvatercept in Duchenne muscular dystrophy on September 28, raising a straightforward question: can a myostatin/activin inhibitor add meaningful muscle benefit on top of what DMD patients already receive? That question matters now because the approved treatment shelf for DMD has grown considerably, from exon-skipping agents to the 2023 gene therapy Elevidys, yet none of those approaches directly address the fibrosis and muscle wasting driven by myostatin and activin A signaling.
The trial (NCT07704099) is an open-label, multi-cohort basket study. Its primary objective is safety and tolerability, which is the right starting point: rinvatercept works as a ligand trap that blocks both myostatin and activin A, proteins that suppress muscle growth and promote fibrosis. Inhibiting them, at least in theory, should increase muscle size, reduce fat infiltration, and slow fibrosis progression. Whether that translates to functional gains in DMD patients, who carry a fundamentally different disease biology than the myeloproliferative conditions where rinvatercept has existing data, is what this study needs to answer.
The basket design is worth noting. Multi-cohort structures let Keros enroll patients across different disease stages or background therapy profiles simultaneously, generating safety signals and early efficacy reads across subgroups without running separate sequential trials. That design choice could accelerate the program’s ability to identify which patient population, if any, responds to the mechanism. It also means early cohort data could inform dose decisions for later cohorts while enrollment continues, a practical efficiency in a rare disease where patient numbers are limited.
The number to track from here is the safety readout from the first cohort. If rinvatercept shows a clean tolerability profile in DMD patients, Keros will have the evidence it needs to expand dosing and begin collecting the functional outcome data that would justify a pivotal program. A signal of muscle benefit on top of existing standard-of-care therapy would be the result that actually changes the program’s trajectory.
Source link: https://www.sec.gov/Archives/edgar/data/1664710/000166471026000056/kros-20260928.htm
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
