On November 25, Novartis announced that its gene therapy Itvisma received FDA approval for the treatment of patients aged two years and older diagnosed with spinal muscular atrophy (SMA) and with a surviving motor neuron 1 (SMN1) gene mutation. Notably, this new therapy uses the same active ingredient as Novartis' earlier Zolgensma therapy, which is primarily designed for SMA patients under two years of age. However, the availability of Itvisma expands the age range of eligible patients and provides them with new treatment options. The wholesale price of Itvisma is $2.59 million, while Zolgensma is $2.1 million.

For SMA patients and their families, the successful approval of Itvisma is a major boon. As the only gene replacement therapy currently available for patients aged two years and older, it marks a new milestone in the treatment of this disease. SMA is a rare, inherited neuromuscular disease primarily caused by mutations or deletions in the SMN1 gene. This gene is responsible for producing most of the SMN proteins essential for muscle function, such as breathing, swallowing, and basic movement. Deletion of the SMN1 gene causes irreversible damage to motor neurons, leading to severe and progressive muscle weakness. While the SMN2 gene can partially replace the function of SMN1, it only produces a small amount (approximately 10%) of the functional SMN protein. Patients carrying more copies of the SMN2 gene typically have milder symptoms.

The approval of itvisma was based on significant results from the STEER registrational phase 3 study and data from the open-label phase 3b study STRENGTH. Patients treated with itvisma reported statistically significant improvements in motor function and demonstrated rare stability of motor ability throughout the natural course of the disease. These positive effects persisted during a 52-week follow-up. Meanwhile, itvisma demonstrated a consistent safety profile across multiple studies, with the most common adverse events being upper respiratory tract infection and fever, but also including the common cold and vomiting.

Itvisma delivers a functional human SMN1 gene to SMA patients via a single epidural, enabling sustained expression of the SMN protein and thus improving their motor function, fundamentally addressing the genetic cause of SMA. Itvisma's innovation lies in its single, fixed-dose treatment, eliminating the need for dosage adjustments based on patient age or weight. By replacing the SMN1 gene, Itvisma not only improves patients' motor function but also promises to reduce the burden of continuous medication compared to other existing therapies.

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