Manufacturing issues block FDA nod for Scholar Rock SMA drug
David Hallal, Scholar Rock's chairman and chief executive.
Unresolved compliance issues at a manufacturing plant operated by Novo Nordisk have led to a complete response letter for Scholar Rock's lead drug for spinal muscular atrophy (SMA).
The CRL is related to an inspection of Catalent Indiana LLC, a fill-and-finish facility in Bloomington that was acquired by Novo Nordisk in December 2024 as part of a multibillion-dollar deal to take ownership of three plants operated by contract development and manufacturing organisation (CDMO) Catalent.
The Bloomington plant was sent a Form 483 notification by the FDA in the summer, which detailed a series of quality issues, including pest infestations, contamination issues, and equipment failures.
The knock-on effect of that now, for Scholar Rock, is a delay to approval of the Biologics License Application (BLA) for SMA treatment apitegromab. In a statement, the Cambridge, Massachusetts-based company said that the CRL included no observations that were specific to its drug, such as safety, efficacy, or drug substance manufacturing.
"We are continuing to work closely with Catalent Indiana on the FDA's manufacturing observations so that we can resubmit the apitegromab BLA as soon as possible," said David Hallal, Scholar Rock's chairman and chief executive.
"We remain focused on working hand-in-hand with the FDA to pursue approval of the first and only muscle-targeted treatment for people living with SMA," he added.
SMA is a genetic disorder that can cause rapid and irreversible loss of motor neurons, affecting muscle functions, including breathing, swallowing, and basic movement.
Scholar Rock filed for approval of apitegromab based on the SAPPHIRE trial, which tested the drug in patients aged two to 12 who were already being treated with the standard therapies for SMA, Biogen's antisense-based therapy Spinraza (nusinersen) and Roche's oral mRNA splicing modifier Evrysdi (risdiplam), which prevent motor neuron loss, but do not directly address muscle.
It achieved a significant improvement in motor function over placebo after 52 weeks of treatment, measured using the 33-point Hammersmith Functional Motor Scale Expanded (HFMSE), which measures a range of physical activities.
Shares in Scholar Rock lost almost 13% of their value on the Nasdaq after news of the CRL emerged, although, the stock has generally been weakening since news of the problems at the Catalent plant were first disclosed.
Outside the US, apitegromab is under review by the EMA, with a decision expected in the middle of next year. If approved, the company has said it expects to launch the drug in Germany as its first European market.
