Synonyms: SRK-015 | SRK015

Compound class: Antibody

Comment: Apitegromab (SRK-015) is an anti-myoststin (GDF8) monoclonal antibody that is being developed by Scholar Rock [2]. Antagonism of myostatin's inhibitory effect on skeletal muscle mass is being predicted to combat muscle atrophy that is observed in patients with the neuromuscular degenerative disease spinal muscular atrophy (SMA). SRK-015 binds to promyostatin and latent myostatin in both serum and muscle [1]. In a mouse SMA model, a precursor of SRK-015 (muSRK-015P) increased muscle mass and function, which is indicative of therapeutic potential.

The primary defect in SMA occurs in defective production of survival motor neuron (SMN) protein and there are already approved drugs that are designed to promote production of functional SMN. Each drug uses a different mechanism to achieve this effect: Roche's Evrysdi® (risdiplam) is a SNM-2 splicing modifier, Biogen's Spinraza® (nusinersen) is an antisense oligonucleotide and Novartis have their gene therapy Zolgensma® (onasemnogene abeparvovec). Myostatin inhibition is likely to be considered as an adjunct to these existing therapies.

Peptide sequences submitted for the INN match patened sequences that are claimed in Scholar Rock's patent WO2017120523A4, and refer to a humanized IgG4 monoclonal referred to as Ab2 in the patent [1].