Hemispherx BioPharma Soars Then Plunges as FDA Panel Votes Against Ampligen Approval

Shares of Hemispherx BioPharma

were extremely volatile on Thursday after the closing bell as an FDA Advisory Committee evaluated the company's application for Ampligen, a drug indicated for the treatment of Chronic Fatigue Syndrome. The vote was 8 to 5 against recommending the approval of Ampligen. The drug's safety profile, however, was backed by the panel. Traders may have thought that this was a strong indication that the panel would vote in favor of approving the drug, because the stock immediately rocketed higher prior to the final decision. After closing at $0.36, HEB soared as high as $0.55 in the after hours. Once it became apparent, however, that the panel had not voted to recommend FDA approval, the bottom fell out of the stock. At last check, HEB was trading down more than 14 percent in the after hours to $0.31.