The FDA has approved another Biogen drug for a neurological disorder. And, unlike the controversial go-ahead for Aduhelm, the agency’s neuroscience division didn’t go against its external advisers’ advice this time.

Tuesday, the FDA granted an accelerated approval to Biogen and Ionis’ tofersen to treat patients with amyotrophic lateral sclerosis (ALS) associated with a mutation in the SOD1 gene. The drug will be sold under the brand name Qalsody.

The move follows the recommendation from an FDA advisory committee in March. At that time, nine experts agreed that Qalsody’s ability to reduce plasma neurofilament light (NfL), a biomarker of nerve injury and neurodegeneration, provides enough basis for a conditional approval. However, thanks to a phase 3 trial flop, the panel voted against full approval.

SOD1-ALS is a small subset of ALS, affecting fewer than 500 patients in the U.S. and about 2% of all 168,000 ALS patients worldwide, according to Biogen’s estimates. Given the limited market size, SVB Securities analysts have put Qalsody’s peak sales potential at about $300 million.

Qalsody is an antisense drug that targets SOD1 mRNA to reduce the production of the SOD1 protein. In a phase 3 trial, the drug showed it can reduce plasma NfL concentration compared with placebo. Both the FDA and its advisers believe the findings are reasonably likely to predict a clinical benefit.

The FDA approval marks a “consensus that neurofilament can be used as a surrogate marker reasonably likely to predict clinical benefit in SOD1-ALS,” Biogen CEO Chris Viehbacher said in a statement. “We believe this important scientific advancement will further accelerate innovative drug development for ALS.”

Still, the drug failed to significantly improve the function of SOD1-ALS patients who had already shown ALS-related weakness. The phase 3 VALOR trial therefore missed its primary endpoint.

Reference:https://www.fiercepharma.com/pharma/sign-biogens-als-drug-qalsody-fda-follows-experts-advice-accelerated-approval