Fat chance, says the little drug maker. Here's the background: There was anObesity Society meeting this week in Washington, DC, and TheStreet.com writes that a Cowen analyst issued an investor accusing Vivus of hiding the extent to which central nervous side effects of its Qnexa fat pill had forced patients to withdraw from two phase III studies.
According to a Cowen analysis of data from the trials presented at the meeting, 2.6 percent and 2.1 percent of patients treated with a full dose of Qnexa dropped out due to such things as "disturbance in attention" or "forgetfulness." For those on placebo, the dropout rates were 0.8 percent and 0.3 percent. Cowen analyst Ian Sanderson wrote Vivus didn't disclose the dropouts when top-line data from the trials was reported in September, according to TheStreet columnist Adam Feuerstein (The In Vivo Blog provides background).
Sanderson wrote that cognitive side effects - memory impairment, amnesia, among other things - could be big hurdles to winning FDA approval, even if rare. "Therefore, we now have reduced conviction in the approvability of Qnexa, and partnering prospects also may be rare," he told clients. Qnexa, by the way, combines two currently approved drugs - phentermine, which was part of the withdrawn fen-phen combo, and Johnson & Johnson's Topamax anticonvulsant - in new formulation.
Not surprisingly, Vivus cfo Tim Morris was livid. "The side effects of Qnexa are expected and within the profile of topiramate. They are mild and manageable and even lower than what you see on the topiramate monotherapy label," he tells TheStreet. Topamax is known to cause cognitive side effects, so it's not surprising some show up in Qnexa patients.
Morris goes on to say Vivus is encouraged since reported side event rates for Qnexa is actually lower than what would be expected with Topamax. He then tells Feuerstein that Sanderson's analysis of the dropout rates "overstates" the issue and is inconsistent with the way the FDA analyzes safety data. And he defended the way Vivus reported safety data in September. "We report data consistent with FDA practice," Morris tells TheStreet, "and there was no intention to selectively disclose."