Keros Therapeutics has received orphan drug designation from the US Food and Drug Administration (FDA) for its investigational therapy KER-065 to treat Duchenne muscular dystrophy (DMD).

KER-065 is a new ligand trap that combines a modified ligand-binding domain from activin receptors IIA and IIB with the Fc domain of a human antibody.

Its mechanism is designed to inhibit the actions of myostatin and activin A ligands, which are involved in muscle signalling.

The therapy aims to enhance skeletal muscle regeneration, increase muscle mass and strength, reduce skeletal muscle fibrosis, decrease body fat and improve bone strength.

The initial focus of KER-065's development is on treating neuromuscular diseases, particularly DMD.

Keros president and CEO Jasbir Seehra stated: “Receiving orphan drug designation for KER-065 highlights the significant unmet medical need for patients with DMD.

“This designation serves as a significant milestone for Keros as we advance KER-065 into a Phase II clinical trial in patients with DMD.”

DMD arises from mutations in the gene responsible for producing dystrophin, a protein essential for myofibre stability.

According to the US National Organization for Rare Disorders, DMD affects approximately one in every 3,500 male births globally.

Keros is engaged in the development and marketing of new therapies for patients with disorders associated with dysfunctional signalling of the TGF-ß protein family.

In April 2025, Keros' board of directors approved a "poison pill defence" due to rising investor interest in “influencing the company’s control.”

This decision follows expressions of interest from certain investors - including one individual with an 11.2% stake in Keros's outstanding common stock - wishing to impact the company's strategic decisions.