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Obesity Drugs May Need Heart Risk Studies Before Approval

March 26 (Bloomberg) -- Obesity treatment manufacturers may need to study the heart risks of their medicines before U.S. regulators weigh approval, Food and Drug Administration staff said in a report today.

Three California companies are competing to bring the first weight-loss pill to market in 13 years: Vivus Inc., Orexigen Therapeutics Inc. and Arena Pharmaceuticals Inc. The FDA is set to decide on Vivus’s drug Qnexa by April 17. Arena’s medication faces an advisory panel on May 10.

An advisory panel will hold a hearing on the drugs in Silver Spring, Maryland, starting March 28. The FDA doesn’t have to follow the panel’s recommendations. The potential approvals come 15 years after the fen-phen appetite-suppression drug combination had to be pulled from pharmacies when it was linked to heart-valve abnormalities. The last obesity drug the FDA approved was Roche Holding AG’s Xenical in 1999.

The advisers will consider whether “obesity drugs without a theoretic risk or signal for” cardiovascular harm “should be required to rule out” some level of cardiovascular risk before approval, the FDA staff said in the report. The regulators don’t have to follow the panel’s recommendations.

Arena gained 25 percent to $3.01 at the close of trading in New York, its biggest one-day increase since Dec. 20, 2010. Vivus dropped 1.4 percent to $21.02, while Orexigen fell less than 1 percent to $4.85.

Arena’s application for review of its diet drug was accepted today by European regulators, according to a statement from the company.

$448 Million

An analysis by Mountain View, California-based Vivus of the risks for Qnexa was “somewhat reassuring,” though the significance of an increase in heart rate was “uncertain,” FDA staff said in a report Feb. 17. Analysts estimate that the drug, if approved, may generate $448 million in sales in 2015.

Vivus has proposed a post-approval trial to assess Qnexa in reducing major heart complications in obese, at-risk patients. The trial would involve 11,300 patients and take four and a-half years. While the pill may have increased heart rate, it had positive effects, including lower blood pressure, on obese people who are normally at risk of heart disease.

The FDA requires makers of type 2 diabetes drugs to study heart risks pre-approval even if no risk signal exists, the agency said in the report.

Qnexa, a combination of the appetite suppressant phentermine and the anti-seizure and migraine medication topiramate, helped patients in clinical trials lose 10 percent of their body weight, Vivus says on its website.

Orexigen’s Contrave

Orexigen agreed in September with the FDA to conduct a two-year study of heart risks for the drug Contrave. The La Jolla, California-based company halted development in June after the agency asked for a large study. The company agreed on a trial with less than 10,000 patients. Orexigen is partnered with Takeda Pharmaceutical Co., based in Osaka, Japan.

Arena is studying its compound lorcaserin to assess cancer risks. The San Diego-based company is partnered with Tokyo’s Eisai Co.

The FDA has previously rejected all three drugs, asking for more data on safety risks, including the likelihood of birth defects associated with Qnexa.

More than 78 million U.S. adults are obese, according to the Centers for Disease Control and Prevention in Atlanta. Obesity raises the risks of diabetes, heart attacks and stroke, and costs the U.S. economy an estimated $147 billion a year in medical expenses and lost productivity, according to the CDC.

To contact the reporter on this story: Anna Edney in Washington at

To contact the editor responsible for this story: Reg Gale at

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