WASHINGTON – U.S. regulators are greenlighting a new weight-loss drug called Contrave, the third in a string of approvals for anti-obesity treatments.
The drug was developed by Orexigen Therapeutics Inc., based in La Jolla, California. The Food and Drug Administration said Thursday that it is approved for use by people who have a body mass index of 30 or higher, which is the level at which people are considered to be obese. It is also approved for use by people with a BMI of 27 or higher who also have a weight-related medical condition such as diabetes.
The agency approved the drug for use in combination with a reduced-calorie diet and exercise.
Contrave is a combination of two drugs that are already approved, naltrexone and bupropion. Naltrexone is used to treat alcohol and narcotic dependence. Bupropion is an antidepressant also used to help people quit smoking.
The combination pill joins two similar drugs from Arena Pharmaceuticals and Vivus Inc. which FDA approved in 2012 after a 13-year drought of new prescription weight-loss medicines. Analysts initially predicted those drugs would garner up to $1 billion in annual sales, considering that more than one-third of all U.S. adults are obese. But sales of Vivus’ Qsymia and Arena’s Belviq have been far below expectations due to limited insurance coverage and high out-of-pocket costs for patients.
Many insurance plans require physicians to get prior approval to prescribe new weight loss medication before paying for them.
Additionally, experts say patients need to have realistic expectations about how much weight they can lose by taking a pill. Patients on Contrave for a year lost 4.2 percent more weight than patients taking a dummy pill.
That compares with weight loss between 3 percent and 3.7 percent for Belviq and 6.7 percent to 8.9 percent for Qsymia, both also measured against placebo.
Drug-induced weight loss is much smaller than that seen with surgical procedures, such as gastric bypass, which can produce a 25 percent to 30 percent drop in weight, on average.
Doctors who treat obesity say they use drugs like Contrave as a chance to educate patients on choosing a healthier, low-calorie diet.
Contrave will have a boxed warning about the risk of suicidal thoughts associated with antidepressants like Bupropion. Additional risks include the possibility of seizures, as well as increased blood pressure and heart rates.
The heart effects created a long road to approval for Contrave. The FDA refused to approve the drug in 2011, citing cardiovascular risks. Orexigen resubmitted its application to regulators in December, saying that the drug fared well in an early analysis of a study designed to rule out excessive cardiovascular risk.
Heart side effects have been a recurring problem with weight loss drugs, most notably the popular diet drug combination fen-phen, which was linked to heart valve damage in the mid-1990s. The cocktail of phentermine and fenfluramine was a popular weight loss combination prescribed by doctors, though it was never approved by the FDA. Fenfluramine was eventually withdrawn from the market.
In 2010, Abbott Laboratories withdrew its drug Meridia after a study showed it increased heart attack and stroke.
Contrave will have an uphill battle in the U.S. market after the disappointing performance of rival treatments from Vivus Inc. and Arena Pharmaceuticals Inc. In the most recent quarter Vivus reported sales of $11 million for Qsymia, while Arena Pharmaceuticals reported $9.9 million in Belviq sales.
Contrave will be distributed in the U.S. by Japanese drugmaker Takeda Pharmaceuticals, which will pay Orexigen royalties on sales. Orexigen and Takeda plan to start selling the drug this fall.
Shares of Orexigen Therapeutics Inc. fell 23 cents, or 3.9 percent, to $5.69 in morning trading.