Can the third time be the charm for weight loss pills?
The Food and Drug Administration on Wednesday approved the third new prescription drug for obesity since 2012. The drug, called Contrave, was developed by Orexigen Therapeutics, a small company based in San Diego, and will be marketed by Takeda Pharmaceutical of Japan.
About one-third of American adults are obese, so a successful weight loss drug could potentially have huge sales. Doctors specializing in obesity say there is a big need for weight loss approaches that go beyond diet and exercise but are not as drastic as surgery.
Yet two drugs approved in 2012 — the first new prescription obesity drugs in 13 years — have had disappointing sales. Those drugs are Qsymia, which is sold by Vivus, and Belviq, which is from Arena Pharmaceuticals and Eisai.
Analysts, doctors and company executives say one reason the drugs have struggled is that many doctors and many obese people do not think of obesity as a disease to be treated by medicine.
Medicare, most state Medicaid programs and some commercial insurers do not pay for the drugs. Doctors and patients are cautious about safety because of problems with previous weight loss drugs. And for many people, the weight loss is modest.
In a clinical trial involving patients without diabetes, those who took Contrave had an average weight loss of 4.1 percent beyond those receiving a placebo. About 42 percent of those getting Contrave lost at least 5 percent of their weight compared with 17 percent of patients in the placebo group.
The F.D.A. declined to approve Contrave in 2011 because there were signs that it slightly raised patients’ pulse rates and blood pressure.
Orexigen then conducted a study with about 9,000 patients to demonstrate that the drug did not raise the risk of heart attacks.
That study is continuing, but interim results have apparently satisfied the regulators.
Orexigen declined to comment before an investor call scheduled for Thursday morning.
Contrave is a combination of two existing generic drugs in an extended-release formulation. One is naltrexone, which is used to treat alcohol and opioid dependence. The other is bupropion, which was approved under the name Wellbutrin to treat depression and under the name Zyban to help people quit smoking.
Contrave’s label has a boxed warning about the risk of suicidal thoughts, which is also on bupropion and other antidepressants.
On Thursday, an advisory committee to the F.D.A. will discuss another possible new obesity drug, liraglutide, from Novo Nordisk. The drug is already sold under the name Victoza as a treatment for diabetes. Novo is proposing a higher dose for use in treating obesity.
Craig M. Audet, a senior vice president at Arena, welcomed the approval of Contrave, saying that having more sales representatives pitching obesity drugs, even rival ones, would increase the market.
“More is better here,” he said. With sales of obesity drugs still low, he said, “it’s much easier to grow the market than try to take market share from somebody.”