Analyst: It's unclear whether Biogen's new Alzheimer's drug will get approved

Alethia Young, biotech analyst and head of health care research at Cantor Fitzgerald, and CNBC's Meg Tirrell join "The Exchange" to discuss the volatility in Biogen stock following release of new data regarding a potential but controversial Alzheimer's drug.
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Thu, Dec 5 20192:38 PM EST