Lowered levels of myostatin result in less fat and more muscle in humans and other mammals. Complete removal of myostatin via genetic engineering or rare natural mutation has resulted in very heavily muscled mice, dogs, cows, and even a few people.
Human gene therapies to either disable myostatin or increase levels of follistatin, the natural inhibitor of myostatin have been successful in mice. Gene therapy delivery will need to be improved to achieve good results in humans.
Researchers have trialed the use of antibodies to reduce the amount of myostatin in circulation. It has some benefits but is not as effective as complete knockout of myostatin.
Antibodies to target latent Myostatin could be more effective with muscle growth
The proprietary therapeutic antibody, SRK-015, was discovered and designed by Scholar Rock to selectively and locally target the latent form of myostatin with the ability to specifically block its intramuscular activation. In a variety of preclinical models of muscle atrophy, SRK-015 has demonstrated improvement in muscle function. SRK-015 is initially being developed by Scholar Rock for the improvement of muscle strength and function in patients with Spinal Muscular Atrophy (SMA) with the treatment of additional neuromuscular diseases to follow.
Scholar Rock is actively working to advance SRK-015 into clinical trials, which are anticipated to commence in mid-2018. We intend to develop SRK-015 in combination with therapies aimed at correcting the underlying genetic defect in SMA (Spinal Muscular Atrophy) and as monotherapy in patients with certain subtypes of SMA (Spinal Muscular Atrophy).