Keros Therapeutics announced that it presented additional clinical data from its Phase 1 clinical trial of KER-065 in healthy male volunteers at the American Society of Bone and Mineral Research 2025 Annual Meeting on Saturday, September 6, 2025.
“We are pleased to present additional data that highlights the broad therapeutic potential of KER-065, including its robust bone anabolic activity,” said Jasbir S. Seehra, President and Chief Executive Officer. “These data continue to demonstrate the potential of KER-065 in Duchenne muscular dystrophy, where bone loss occurs as a result of the progressive muscle weakness and chronic use of corticosteroids.”
KER-065 Clinical Presentation
This Phase 1 clinical trial was a randomized, double-blind, placebo-controlled, two-part dose escalation (single and multiple ascending dose) trial in healthy male volunteers. The primary objectives of this trial were to assess safety, tolerability and pharmacokinetics of KER-065. Exploratory endpoints include assessments of the pharmacodynamic effect on bone, adipose, muscle, cardiac tissue and fibrosis. Initial topline data from this trial was reported in March 2025. – Read More –
As of the final data cut-off date of April 29, 2025, treatment with KER-065 was generally well-tolerated at all dose levels tested. No dose-limiting toxicities or serious adverse events were reported. One grade 4 treatment-emergent adverse event of elevated creatine kinase levels was observed, but deemed unrelated to treatment. The majority of the adverse events that were observed were mild to moderate in severity and resolved.
Additional results from this trial, as of the data cut-off date, demonstrated that treatment with KER-065 resulted in:
- Changes in bone biomarkers of increased bone formation and reduced bone resorption that were consistent with tissue level changes, as demonstrated by observed increases in bone mineral density (“BMD”)
- Whole body BMD improvements at Day 85 that were sustained through Day 141 (three months after the last dose in the multiple ascending dose cohorts), suggesting a balance between osteoblast and osteoclast activity
- Increased lumbar spine BMD following three doses that were sustained through Day 141
What is KER-065?
KER-065 is a novel ligand trap comprised of a modified ligand-binding domain derived from activin receptor type IIA and activin receptor type IIB that is fused to the portion of the human antibody known as the Fc domain. KER-065 is designed to act as a ligand trap and inhibit the biological effects of myostatin and activin A, two ligands that signal through activin receptors, to increase skeletal muscle regeneration, increase muscle size and strength, reduce body fat, reduce fibrosis of the skeletal muscle and increase bone strength.
