Vivus has outlined the effectiveness of its weight-loss drug Qnexa in keeping the pounds off patients for two years running, but the jury's still out on whether the biotech offered enough additional insight on potential long-term safety issues to persuade the FDA to overlook its expert panel's concerns and approve the therapy.
In a surprise vote in July, 10 of 16 FDA experts concluded that they didn't know enough about Qnexa's long-term effects to warrant an approval. Many panel members thought the drug, a combination of phentermine and topiramate, could pose a safety issue for pregnant women, regardless of the way the label is written. And other potential issues, like the threat of depression and potential memory problems along with the prospect of cardiovascular side effects, weighed against the drug as well.
In its release this morning, Mountain View, CA-based Vivus underscores that researchers saw no new safety issues at two years than they did at one.
"SEQUEL data confirms previous safety findings, with no evidence of suicidality and no reports of suicidal attempts or behavior. Depression assessments, as measured by the PHQ-9 clinical depression scale, improved from baseline for all treatment groups," Vivus states. "The incidence of targeted medical events for sleep disorders, depression, anxiety, cardiac disorders and cognitive disorders in SEQUEL was lower than observed during the one-year CONQUER study."
At the top dose patients sustained an average weight loss of 26 pounds, or 11.4 percent. A mid-dose sparked an average of 10.4 percent, while placebo patients lost 2.4 percent. That's good enough to meet the agency's standards for weight loss. But the panel's safety concerns were vague enough to leave analysts scratching their heads over what could be done to resolve the experts' worries. The FDA will make its decision by late October. Vivus is racing Orexigen and Arena to gain the first new approval for a weight loss drug in more than a decade, but the safety hurdles are huge.