Data questions raised on Zolgensma US approval

Following US Food and Drug Administration approval of gene therapy Zolgensma (onasemnogene abeparvovec-xxxx) on May 24, the agency said on Tuesday that, on June 28, it was informed by AveXis, the product’s manufacturer and developer, about a data manipulation issue that impacts the accuracy of certain data from product testing performed in animals submitted in the biologics license application (BLA) and reviewed by the FDA.

AveXis was acquired by Swiss pharma giant Novartis (NOVN: VX) in April last year in an $8.7 billion deal. Zolgensma became the first gene therapy approved to treat children less than two years of age with spinal muscular atrophy (SMA), the most severe form of SMA and a leading genetic cause of infant mortality. It also became the world’s most expensive drug, with a treatment cost of $2.1 million.

Shares in Novartis fell 3% to $88.08 in afternoon trading in New York after the FDA statement, but are virtually unchanged this morning of the Swiss stock exchange’