The company says that while the treatment for an inherited form of amyotrophic lateral sclerosis didn't reach the primary endpoint of the trial, the drug did show promising data.
"The results from the VALOR study are encouraging as they show reduction of SOD1 protein, reduction of neurofilament, a potential biomarker for neurodegenerative disease, and positive signals across multiple key endpoints including measures of important aspects of the daily lives of SOD1-ALS patients,” said Timothy Miller, M.D., Ph.D., principal investigator of VALOR and ALS Center Director at Washington University School of Medicine, St. Louis.
Biogen is engaging with regulators, the medical community, patient advocacy groups and other key stakeholders around the world to determine its potential next steps, according to a company statement.
Shares of Biogen on Monday closed 4.1% to $269.73.
Tofesen was administered directly into the spinal canal of patients each month during the trail. The treatment is designed to suppress the production of SOD1, a protein that can accumulate to toxic levels in ALS patients with mutations in a specific gene.
About 2% of ALS cases are believed to be caused by the genetic mutation, according to Reuters.
Most side effect in trial patients were mild to moderate, but two patients did experience spinal cord inflammation, while 5.6% of patients in the study dropped out.