Itvisma CHMP Opinion Opens Gene Therapy to Adult SMA Patients

Novartis now faces the manufacturing and regulatory infrastructure challenge of delivering a fixed-dose intrathecal gene therapy across a significantly broader patient population in Europe, following the Committee for Medicinal Products for Human Use (CHMP) positive opinion recommending marketing authorisation for Itvisma (intrathecal onasemnogene abeparvovec) for patients aged two years and older with 5q spinal muscular atrophy (SMA) carrying a bi-allelic SMN1 mutation. If the European Commission converts the opinion to approval within its expected two-month window, Itvisma will become the first and only gene replacement therapy available to children, adolescents, and adults with SMA in the EU, a population segment historically excluded from gene therapy access.

The fixed-dose model, requiring no adjustment for age or body weight, carries distinct CMC implications. Unlike weight-tiered dosing strategies common in paediatric gene therapy, a single dose specification across a wide patient range demands tightly controlled vector genome titre consistency and robust comparability data across manufacturing lots. The CHMP opinion is supported by data from the registrational Phase III STEER study, the Phase IIIb STRENGTH study, and the Phase I/II STRONG study. In STEER, Itvisma demonstrated a statistically significant 2.39-point improvement on the Hammersmith Functional Motor Scale (HFMSE) versus 0.51 points for sham at a p-value of 0.0074, with effects sustained over 52 weeks. Results from STEER and STRENGTH were published in Nature Medicine.

Clinical context matters for QA and regulatory teams interpreting the benefit-risk profile. Professor Tim Hagenacker of University Hospital Essen noted that even a one-point difference on the HFMSE can translate into tangible functional gains, such as the ability to grasp a pen, underscoring the sensitivity of the scale in a progressive neuromuscular disease where preserving existing motor function is a primary therapeutic goal. The STEER and STRENGTH studies demonstrated clinically meaningful benefit for both treatment-naive and pre-treated patients, a finding with direct implications for labelling scope and post-authorisation effectiveness commitments.

The CHMP opinion follows Zolgensma's established role in infants and young children with SMA, and Novartis has positioned Itvisma as an extension of that portfolio to older patients. The European Commission is expected to issue a final decision within approximately two months of the CHMP recommendation. Regulatory affairs and manufacturing teams tracking EU gene therapy precedents should monitor the EC decision timeline and any conditions attached to the marketing authorisation, particularly around pharmacovigilance obligations and risk management plan requirements for a one-time gene replacement administered intrathecally at scale.