Sales of anti-obesity drugs, while relatively small, did nearly double from 2011 to 2013, according to IMS Health. During that time, Qsymia, the first new weight-loss drug in 13 years, entered the market in September 2012. Belviq became available in June 2013.
The drugs are approved to treat obese people, those with a body mass index (BMI) of 30 or higher, and overweight people with at least one weight-related condition, such as type 2 diabetes or high blood pressure, whose BMI is 27 or higher. (The FDA was expected to approve another weight-loss drug, Contrave, in June, but the agency delayed a decision by 3 months. It wants to further discuss how to track the drug’s heart effects once it comes on the market.)
In the two clinical trials that led to Qsymia’s FDA approval, people treated with the recommended starting dose lost 6.7% more weight in a year than those given a placebo pill. People treated with the highest dose lost 8.9% more weight in a year than those on a placebo.
In the three clinical trials that led to Belviq’s FDA approval, people who took the drug for up to 1 year on average lost 3% to 3.7% more compared to placebo. Both medications are supposed to be used along with lifestyle changes, namely eating less and exercising more.
Even if doctors prescribe the pills, patients are likely to find their health insurance won’t pay for them, Smith says. “Coverage is key,” he says, noting that fewer than half of health insurance companies cover weight-loss drugs. “We have 50, 60 diseases that are caused by obesity. We’re happy to replace your knees, but we’re not addressing the root problem."
Obesity specialist Caroline Apovian, MD, a professor of medicine at the Boston University School of Medicine, says lack of insurance coverage for anti-obesity medications is the reason phentermine, a generic drug, is the most-prescribed weight-loss drug in the U.S.
Years ago, phentermine was combined with fenfluramine, in a drug known as fen-phen. The drug was widely prescribed for weight loss until the FDA banned fenfluramine in 1997 after it was linked to heart valve problems.