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Biogen plummets on ending drug trial, its pipeline remains very high risk- Jefferies analyst

Biogen stock plummet after announcing it is abandoning trials on an Alzheimer drug. Jefferies Senior Biotechnology Analyst Michael Yee tells Yahoo Finance's Jackie DeAngelis that Biogen is probably going to be range-bound and will be set up for another very binary event about a year from now on its multiple sclerosis patent challenge decision.