Highlights of weekly biotech stock moves

ViroPharma Inc. (NASDAQ:VPHM) fell $6.17 (22%) to $22.44 on Tuesday after FDA approved three generic versions of Vancocin vancomycin and the company said the Federal Trade Commission is investigating whether it engaged in unfair methods of competition with respect to the oral antibiotic. ViroPharma reported $288.9 million in 2011 net Vancocin sales. The stock was off $8.05 (27%) to $22.01 last week.

Vivus Inc. (NASDAQ:VVUS) lost $0.39 to $22.14 last week after FDA extended by three months to July 17 the PDUFA date for an NDA for Qnexa to treat obesity. According to Vivus, FDA needed more time to review an updated REMS proposal submitted by the company for the fixed-dose combination of phentermine and topiramate at the agency's request...