On Tuesday, shares of biopharmaceutical company Biogen (BIIB Quick QuoteBIIB - Free Report) are plunging, down over 15% in afternoon trading after the company’s Phase 2 study of its treatment for relapsing multiple sclerosis failed to meet its primary and secondary endpoints.

The drug, opicinumab, did not meet the primary objective of the improvement of physical and cognitive function and disability, while the secondary objective was slowing of disability progression.

"Achieving repair of the human central nervous system through remyelination would be a substantial achievement, and while we missed the primary endpoint, the SYNERGY study results suggest evidence of a clinical effect of opicinumab," said Chief Medical Officer Alfred Sandrock. "Due to the complex nature of the data set, we continue to analyze the results to inform the design of our next study."

Biogen added that opicinumab was generally well tolerated and showed a linear, well-behaved PK profile over the studied dose range.

So far this year, BIIB has underperformed the broader markets, dropping over 5% as of Monday’s close.

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