MOUNTAIN VIEW, Calif. ( TheStreet) -- In a review posted to its Web site Tuesday, U.S. drug regulators said Vivus' (VVUS - Get Report) weight-loss drug Qnexa was effective in helping obese patients shed pounds, but the agency raised questions -- most of them expected -- about the drug's safety.
Vivus shares were up about 34% to $14.25 in Tuesday's pre-market trading session as anxious investors breathed a sigh of relief over the U.S. Food and Drug Administration's relatively benign review of Qnexa, which didn't yield any "Uh Oh!" revelations about the drug's safety.
The FDA will convene an outside panel of experts Thursday -- which TheStreet will be covering via live blog -- to review Vivus' approval application for the weight-loss drug Qnexa. Vivus is trying to become the first company in more than a decade to gain U.S. approval for a new weight-loss drug. Two other companies -- Arena Pharmaceuticals (ARNA - Get Report) and Orexigen Therapeutics (OREX - Get Report) -- are fast on its heels.In the FDA's review of Qnexa, posted online Tuesday as part of the briefing documents for Thursday's advisory panel, pooled data from two large phase III studies demonstrated that patients treated with low, medium and high doses Qnexa lost between 3 percent, 7 percent and 9 percent of their body weight, respectively, adjusted for the weight-loss reported for patients treated with a placebo. Twenty percent of placebo-treated patients lost more than 5% of their body weight, compared to 45 percent, 62 percent and 69 percent of Qnexa patients. According to the efficacy criteria laid out by FDA for weight-loss drugs in 2007, the FDA concluded that, "all three doses of PHEN/TPM