FDA Gives 3-Month Extension of New Drug Application Review for Tofersen to Treat Superoxide Dismutase 1 Amyotrophic Lateral Sclerosis

The Food and Drug Administration (FDA) has extended the review period of the new drug application (NDA) for tofersen (Biogen, Cambridge, MA) superoxide dismutase 1 (SOD1) amyotrophic lateral sclerosis (ALS) treatment to April 25, 2023. 

Tofersen was evaluated in the phase 3 VALOR study (NCT02623699) where participants with SOD1-associated ALS had slowed disease progression when treated. Data from the VALOR study and the open-label extension demonstrated sustained reductions in SOD1 protein after adjustments for neurofilament levels were made.

“We are committed to providing any details the agency needs to complete the review of tofersen,” said Priya Singhal, MD, MPH, head of Global Safety and Regulatory Sciences and Interim Head of R&D at Biogen. “As the review continues, Biogen will maintain the early access program for tofersen.”

The FDA accepted the tofersen NDA in July 2022 under the accelerated pathway and granted priority review.