Rare Daily Staff

Novartis-owned AveXis reported interim data from ongoing trials of its experimental gene therapy Zolgensma that showed positive results across a broad spectrum of patients with spinal muscular atrophy, a severe and deadly neuromuscular disease.

Spinal muscular atrophy (SMA) is characterized by the loss of motor neurons leading to progressive muscle weakness and paralysis. SMA is caused by a genetic defect in the SMN1 gene that codes SMN, a protein necessary for survival of motor neurons. It is the leading genetic cause of infant mortality. The most severe form of SMA is type 1, a lethal genetic disorder characterized by rapid motor neuron loss and associated muscle deterioration, which results in mortality or the need for permanent ventilation support by 24 months of age for more than 90 percent of patients.

Zolgensma is an experimental gene therapy currently in development as a one-time infusion for SMA Type 1. Zolgensma is designed to address the genetic root cause of SMA and prevent further muscle degeneration by providing a functional copy of the human SMN gene to halt disease progression through sustained SMN protein expression. Zolgensma was developed in partnership with Genethon. The drug previously received Breakthrough Therapy designation and has been granted Priority Review by the U.S. Food and Drug Administration (FDA), with regulatory action anticipated in May 2019. In addition, the drug is anticipated to receive approval in Japan and the European Union later this year.

In a presentation at the 2019 American Academy of Neurology (AAN) annual meeting, investigators reported data from the phase 1 STRONG trial showed motor function gains and milestone achievements in patients with SMA Type 2 through intrathecal delivery.

“With an average of just over six months of data available for these Type 2 patients following treatment with Zolgensma, we are pleased to see they are achieving motor milestones, including the ability to stand and walk,” said Olga Santiago, chief medical officer of AveXis. “Based on these early promising data, we plan to approach regulators to define the path to registration for intrathecal administration of Zolgensma.”

In separate presentations at AAN, investigators reported new data from the phase 3 STR1VE trial of the gene therapy that continued to show prolonged event-free survival. It also reported data from the phase 3 SPR1NT trial of the gene therapy that showed motor milestone achievement consistent with normal development in SMA patients treated pre-symptomatically.

“With just a single, one-time dose, we are seeing Zolgensma provide prolonged survival, rapid motor function improvement and milestone achievements that patients never experience if their disease is left untreated,” said David Lennon, president of AveXis. “These robust data presented at AAN represent a growing body of evidence that support the use of Zolgensma as a potential foundational therapy for the treatment of SMA across a variety of populations.”

Photo: David Lennon, president of AveXis

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