Safety Data On Vivus’s Qnexa Doesn’t Cut It For FDA Panel-UPDATED
You have to feel for the FDA's Endocrinologic and Metabolic Drugs Advisory Committee this week. They'd just finished the Avandia slog, but there was no rest for the weary. No, instead, they got to sink their teeth into the first of the potential new obesity drugs, Vivus' Qnexa.
In a vote that signals safety is king in the obesity drug realm, Qnexa got a thumbs down from the panel this afternoon. The panel was split, with 7 members recommending that FDA should approve the drug and 9 recommending against approval.
The panel's take home message was that a lack of safety data led to their decision.
Several journalists live-blogged the panel session. Here are the two play-by-plays I followed:
Lisa LaMotta, Minyanville
Adam Feuerstein, TheStreet
This decision comes after what seemed like an optimistic week for Vivus. On Tuesday, when FDA released its briefing documents about Qnexa, media reports on the data suggested that even though the agency's review focused on safety, it didn't look like safety would be a dealbreaker. In a note to investors, Leerink Swann analyst Steve Yoo wrote, "Overall, we believe the language in the FDA briefing documents to be fairly benign, but the FDA is requesting a pregancy category X label that would include contraindication in pregnant women and a warning/ precaution for females of childbearing potential."
At today's panel, as expected, nobody really dwelled on Qnexa's efficacy. But Vivus faced a lot of questions about safety, especially about the effects of Qnexa during a pregnancy. During clinical trials, 13 women on Qnexa gave birth, and none of the babies had birth defects. Because Qnexa is likely to be an appealing option for women of reproductive age if it's approved, panelists were concerned that more data are needed to make sure Qnexa is safe during pregnancy. That's because one of the components of Qnexa is topiramate, an epilepsy drug that is known to carry a risk of birth defects. What complicates things is that the dose of topiramate in Qnexa is lower than the dose used for treating epilepsy. It's also lower than the doses used in studies that suggested topiramate carries a risk of birth defects.
The panel also discussed the other four safety concerns mentioned in the briefing documents:
But at the end of the day, panelists who voted 'no' felt like more long-term safety data was in order. From Feuerstein's liveblog:
one of the "no" votes says obesity is a chronic disease, so tell me what happens to patients as they stay on the medication for years.
The deadline for FDA to make a decision on Qnexa is October 28. So it might be a while before we hear the final word. Vivus has time to come up with more safety data.
Trading on Vivus's shares was stopped today because of the hearing but will start again tomorrow. Shares for Arena and Orexigen, the other two big players in the obesity drug race, fell late today. It was a bit of a rollercoaster day for Arena, since shares soared earlier today because of new lorcaserin data published in the New England Journal of Medicine.
UPDATE July 16: Yesterday evening Vivus responded to the news in a conference call. In an accompanying press release, the company noted that "The vote from the Endocrinologic and Metabolic Drugs Advisory Committee is a recommendation. The FDA will take the Committee's recommendation into consideration during its review of the current application and will make a determination. The FDA may or may not follow the Committee's recommendation."
Leland Wilson, Vivus' CEO, said in the release "We appreciate the Advisory Committee's recognition of obesity as a significant health crisis, and the challenges associated with the treatment of this disease."
"We are disappointed with the Advisory Committee's vote. While the final vote was close, and we are encouraged that the Committee recognized the efficacy demonstrated in the QNEXA clinical trials, we will work closely with the FDA leading up to our October 28, 2010 PDUFA date to address the labeling and safety questions raised during today's proceedings. We remain committed to patients living with obesity and weight-related disease."