Apitegromab (SRK-015) is a muscle-directed therapy that aims to reverse or restrict the muscle atrophy and weakness experienced by SMA patients. The drug is an antibody that very specifically targets an important protein called myostatin, which restricts muscle mass and strength. Scholar Rock believes that by preventing the activation of myostatin, a clinically meaningful increase in muscle mass and strength will be achieved.
The U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) and the European Medicines Agency (EMA) has granted Orphan Medicinal Product Designation, to apitegromab for the treatment of SMA.
Scholar Rock initiated a Phase 2 proof-of-concept clinical trial, TOPAZ, to assess the safety and efficacy of apitegromab in patients with Type 2 and Type 3 SMA. Enrolment was completed in January 2020.
The trial includes three cohorts, each representing a distinct subpopulation of patients: