Scholar Rock’s apitegromab is awaiting a US manufacturing facility resolution, which may impact the therapy’s European review, for which clinical assessment has been completed.
The European Medicines Agency’s (EMA) review of US-based biopharmaceutical company Scholar Rock’s
The timing of a Committee for Medicinal Products for Human Use (CHMP)
According to Scholar Rock, the EMA is continuing its scientific review of apitegromab while awaiting an FDA update on the inspection classification of the Catalent Indiana fill/finish facility, which was included in the European MAA. If FDA reclassifies the site, the company expects a CHMP opinion later in 2026. Otherwise, Scholar Rock said it plans to work with the EMA to substitute a second fill/finish facility already included in the biologics license application currently under FDA review.1
The US application has a Prescription Drug User Fee Act target action date of September 30, 2026. FDA had previously issued a complete response letter in 2025 that cited manufacturing observations at the Indiana facility without identifying additional approvability concerns related to apitegromab itself.
Apitegromab is an investigational fully human monoclonal antibody that selectively inhibits activation of myostatin, a negative regulator of skeletal muscle growth. Unlike approved SMA therapies that increase survival motor neuron (SMN) protein, apitegromab is designed to improve muscle strength by targeting downstream muscle biology and has been studied as an add-on therapy to standard SMN-directed treatment.2,3-4
The regulatory submissions are supported primarily by results from a phase 3 trial (SAPPHIRE), which evaluated apitegromab in patients with type 2 and type 3 SMA receiving background SMN-directed therapy. Scholar Rock has reported that the study met its primary efficacy endpoint, demonstrating statistically significant improvements in motor function compared with placebo. Full peer-reviewed publication of the pivotal data has further characterized efficacy and safety outcomes.2
The current update concerns manufacturing and regulatory logistics rather than a reassessment of clinical data. Manufacturing inspections remain a critical component of biologics approval, and deficiencies identified at 3rd-party manufacturing facilities can delay regulatory decisions even when product-specific clinical evidence is considered acceptable.
Scholar Rock stated that its alternative fill/finish facility is already producing commercial products and is in good standing with both FDA and EMA inspections, potentially providing an alternative pathway should the Catalent Indiana classification remain unresolved.
Although the company continues to anticipate regulatory progress in both the United States and Europe during 2026, the ultimate timing of European authorization will depend on manufacturing-related regulatory decisions outside the scope of the clinical review. Additional updates are expected during the company's August earnings call.
