New top-line data from Scholar Rock Holding Group’s phase II Topaz trial of apitegromab (SRK-015) in patients with type 2 and type 3 spinal muscular atrophy generated enough proof-of-concept results for the company to plan on initiating a phase III for later this year. But the 12-month data didn’t stop the Cambridge, Mass.-based company’s stock (NASDAQ:SRRK) from struggling mightily on April 6 as shares closed 20.3% lower at $35.97 each.