Cambridge's Scholar Rock Snags Another $47M to Take on Rare Neuromuscular Disease

Scholar Rock announced it had closed on a Series C financing worth $47 million. The round was led by new investor Invus, with participation of another new investor, Redmile Group. All existing investors participated, including Polaris Partners, Timothy Springer, ARCH Venture Partners, EcoR1 Capital, The Kraft Group, Fidelity Management and Research Company, and Cormorant Asset Management.

The company closed on a Series B worth $36 million on Jan. 4, 2016. That round was led by Fidelity Management and Research Company.

Scholar Rock focuses on a protein called myostatin, which is involved in various wasting diseases that limit muscle growth. The proceeds of the most recent financing will be used to advance SRK-015, its lead clinical candidate for Spinal Muscular Atrophy (SMA) and other neuromuscular disorders. The company will evaluate SRK-015’s ability to improve muscle strength and motor function in SMA patients on therapies that upregulate the production of the deficient SMN protein, as well as a monotherapy in subpopulations of SMA patients.

The company also indicates that it hopes to have funds available to expand its development candidates in fibrosis, immuno-oncology, and anemias linked to iron restriction.

“We are delighted by the strong support and recognition we received in this Series C financing and the expansion of our group of world-class life sciences investors, which now includes Invus and Redmile,” said Nagesh Mahanthappa, Scholar Rock’s president and chief executive officer, in a statement. “We expect 2018 to be a critical year of growth for Scholar Rock, as we advance the first clinical candidate from our groundbreaking platform into the clinic to address an important unmet need in SMA and continue to build out our pipeline.”

In December 2016, the U.S. Food and Drug Administration (FDA) approved Biogen’s Spinraza for SMA, making it the first and only treatment for the disease approved in the U.S.

Mahanthappa told Endpoints News’ Brittany Meiling, “[Spinraza] addresses the primary issues with SMA—the loss of motor neurons in the spinal cord. But they’re not addressing the atrophy and muscle weakness that is a consequence of that loss of motor neurons.”

SRK-015 inhibits the supracellular activation of latent myostatin. Myostatin regulates and breaks down muscle mass. The theory is that by inhibiting myostatin’s degradation function, it will allow for more muscle to grow.

Scholar Rock and Biogen are not the only companies working in the area. Novartis's bimagrumab works similarly to SRK-015 and GlaxoSmithKline, Sanofi, Eli Lilly, Pfizer, Regeneron Pharmaceuticals, and Bristol-Myers Squibb are all working on myostatin-related diseases, including Duchenne muscular dystrophy (DMD), cancer, and sarcopenia, a type of age-related muscle loss.

Mahanthappa differentiated Scholar Rock’s approach to Meiling, saying, “Imagine you’re in your home, and you want to turn off the lights in one room. You can do that in two ways, you could turn off the switch in that room or you could cut off the electricity in the entire house. First generation drugs do the latter, while Scholar Rock is attempting the former.”