FDA panel rejects VVUS' Qnexa, citing safety worries

http://blogs.wsj.com/health/2010/07/15/fda-panel-rejects-vivuss-qnexa-citing-safety-worries/?mod=yahoo_hs

Vivus’s Qnexa, the first of three new anti-obesity drugs under FDA review this year, came before one of the agency’s advisory committees today — and it was a swing and a miss. The panel recommended against approval, with 10 panel members voting against it and 6 in favor, as the WSJ reports.

Trading in the company’s shares was halted at $12.38. But shares in Arena, which makes one of the other experimental drugs, lorcaserin, were up more than 9% in after hours trading, to $4.30. Shares in Orexigen, which makes the other drug, Contrave, fell 10% in after-hours trading, to $4.50. Contrave is similar to Qnexa in that it, too, is a combination of existing drugs.

The problem wasn’t Qnexa’s effectiveness. But panel members said that safety concerns, such as birth defects, depression, and a high heart rate experienced by some study participants, were worrisome in light of the fact that the drug might be taken by millions of otherwise healthy people over many years. They wanted longer-term data than the company had available in order to assuage safety concerns.

Topiramate not recommended for treatment of obesity

http://www.apmhealtheurope.com/story.php?mots=TOPIRAMATE&searchScope=1&searchType=0&numero=L7098

Topiramate is one of two generic compounds in Qnexa, the other being phentermine. Qnexa is being reviewed by an independent advisory committee today, and will receive full review by the FDA on October 28. Draw your own conclusions.

Disclosure: no position in VVUS.

More excerpts from FDA briefing document on Qnexa

"When assessed as a group, the incidence of cognitive-related adverse events was 1.7%, 2.0%, 5.6%, and 7.8% in the placebo, low-dose, mid-dose, and high-dose PHEN/TPM groups, respectively. The most common adverse event related to cognitive dysfunction was disturbance in attention."

"Approximately 30% of individuals treated with high-dose PHEN/TPM experienced a
serum bicarbonate <21 mEq/L compared to 5.9% of individuals treated with placebo."

"A higher proportion of PHEN/TPM-treated individuals experienced a categorical
increase in heart rate compared to placebo treated individuals (>20 bpm: 19.6% high-dose PHEN/TPM versus 11.9% placebo)."

"Six individuals in the placebo group (atypical angina, coronary artery disease, left main coronary disease) and five individuals in the PHEN/TPM group experienced a non-fatal serious adverse event related to cardiac ischemia defined within this subclass. An additional placebo-treated individual died of cardiorespiratory arrest. Coronary artery disease was the most common adverse event within the placebo group and myocardial infarction was the most common adverse event within the PHEN/TPM-treated group."

"The incidence of depression-related adverse events in the PHEN/TPM clinical trials was 3.4% in the placebo group, 5.0% in the low-dose PHEN/TPM group, 3.8% in the mid-dose PHEN/TPM group, and 7.7% in the high-dose PHEN/TPM group."

These adverse side effects are problematic for Qnexa, in my opinion. We should find out more in today's independent advisory committee review, and the October 28 PDUFA event.

VVUS shares increase on Qnexa efficacy, despite safety concerns

Shares of Arena Pharmaceuticals and Orexigen also rise in sympathy with Vivus. Briefing documents for Qnexa's upcoming review by an independent advisory committee this Thursday (July 15) revealed Qnexa's efficacy for weight loss, but also expressed concerns regarding adverse side effects. The FDA has assigned a PDUFA date of October 28, 2010, for review of Qnexa's NDA.

http://finance.yahoo.com/news/Vivus-weight-loss-drug-faces-apf-1308428575.html?x=0&.v=2

See disclaimers on the side bar.

Disclosure: long ARNA shares.

VVUS's Qnexa advisory committee

Qnexa has an advisory committee review July 15, but the FDA's documents will be available July 13. I have many reservations on Qnexa's approvability, including censorship of titration drop out data, the high discontinuation rates, adverse side effect profile, among others. But this one could also be discomforting to VVUS investors:

VVUS's latest 10-Q :
"The number of patients on the low-dose in OB-302 or the mid-dose in the OB-303 study may not be sufficient for approval."

With drugs facing increasing scrutiny regarding safety from the FDA, Qnexa faces some head winds in the regulatory process, in my opinion. We'll find out soon enough later this week.

See disclaimers on the side bar.

Disclosure: no position in VVUS.