Scholar Rock wins FDA approval for spinal muscular atrophy drug Isembyld
The company says it misspoke on a September call about post-marketing safety obligations attached to the approval
Published
The FDA has approved Isembyld (apitegromab-mstn) for spinal muscular atrophy in patients 2 years and older who are already on an SMN2-targeted treatment, Scholar Rock said.
The company also said that during the question-and-answer portion of an investor call on 14 September 2026, management stated in error that the FDA had not required any post-marketing safety commitments. In fact, the agency has required Scholar Rock to run a pregnancy safety study tracking complications and birth outcomes in exposed pregnancies, and to submit all serious and non-serious fracture cases as 15-day alert reports. Scholar Rock said it intends to carry out the study and file the reports as required.
The approval itself is unaffected by the error. The pregnancy study and fracture reporting are standard conditions for this class of drug and do not narrow what Isembyld is approved to treat. What the misstatement leaves exposed is confidence in management's own account of the approval it just won, on a call meant to explain that approval to investors.