US regulators have accepted for review Novartis’ Biologics License Application for Zolgensma, an investigational gene replacement therapy for the treatment of spinal muscular atrophy (SMA) Type 1.

The application has been given a priority review, which means that the drug giant can expect a decision from the US Food and Drug Administration within six months as opposed to the standard 10 months.

Zolgensm (AVXS-101, onasemnogene abeparvovec) is designed to address the genetic root cause of the condition, which is a deadly neuromuscular disease with limited treatment options.

In the START trial, all 15 patients infused with Zolgensma were alive and without the need for permanent ventilation at 24 months. Also, 92% of patients could also sit unassisted for five seconds or more, a milestone never achieved in the natural history of SMA type I, the firm notes.

At the 24-month follow up, 100% of patients who were over all 24 months of age were event-free, as opposed to only 8% of patients in a natural history study.

“This important step by the FDA brings us ever closer to delivering Zolgensma to patients with SMA type I,” said David Lennon, president of Novartis company AveXis.

“Babies affected by this rare disease are currently faced with debilitating disease progression and lifelong invasive chronic treatment. As a one-time infusion that addresses the genetic root cause of SMA without the need for repeat dosing, Zolgensma represents a potentially significant therapeutic advance for these patients and their families."