Should Biogen Investors Be Preparing for the Worst?

Just when the Aduhelm controversy started to settle down, Biogen (NASDAQ: BIIB) disappointed again for what it was hoping was its next big hit. Tofersen, its investigational RNAi drug for amyotrophic lateral sclerosis (ALS), perhaps better known as Lou Gehrig's disease, didn't quite produce results as hoped last week. On top of this setback, sales are slipping.

With a market cap of nearly $40 billion, the pharmaceutical company came up empty-handed in a phase 3 study evaluating the efficacy and safety of tofersen in adults with a specific mutation called SOD1, which affects about 2% of patients with the progressive neurodegenerative disease. There was no effect on clinical function or respiratory function, and with 5.6% of patients having serious neurologic adverse events in the treatment group versus zero in the control group, things are looking bleak for tofersen's future.

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Source Fool.com