New weight loss drug approved

The first new weight-loss drug in 13 years was approved Wednesday by the U.S. Food and Drug Administration.

The drug, Belviq (lorcaserin), was approved for obese adults who have high blood pressure, high cholesterol or type 2 diabetes, and is to be used in combination with a low-kilojoule diet and exercise, the FDA said.

"Obesity threatens the overall well-being of patients and is a major public health concern," Dr Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said. "The approval of this drug, used responsibly in combination with a healthy diet and lifestyle, provides a treatment option for Americans who are obese or are overweight and have at least one weight-related comorbid condition."

Potential risks

However, Dr David L. Katz, director of Yale University's Prevention Research Center, said that even the best weight-loss drugs can do little to reverse a problem now affecting much of the population.

"Belviq is unlikely to rank among the best of drugs," he said. "While it is better than placebo at fostering weight loss, its effects appear to be modest. And while trial results are reassuring so far, there are still concerns about a potential for damage to heart valves seen with drugs of this kind."

Right now there is no information of the cost of the Belviq, said David Schull, a spokesman for Arena Pharmaceuticals GmbH of Zofingen, Switzerland, the maker of the drug. It will be distributed in the United States by Eisai Inc., of Woodcliff Lake, N.J.

"Eisai will launch the drug after the Drug Enforcement Administration completes its scheduling," he said. "More information will follow as Eisai moves toward launch."

This isn't the first time Belviq was up for FDA approval. In 2010, Arena sought approval but was turned down because animal studies showed the drug was associated with tumour growth.

New data supplied to the FDA that allayed these fears led to the drug's approval.

How the drug works

The drug works to help suppress appetite by activating an area of the brain called the serotonin 2C receptor. The weight-loss drugs fenfluramine and dexfenfluramine, best known as "fen-phen," targeted a different part of the serotonin system, and were pulled for the market because they boosted the risk of heart valve damage.

Belviq was tested in three trials that included nearly 8 000 obese and overweight people who were treated for a year or more. Treatment also included dieting and exercise. Those taking Belviq for a year lost 3% to 3.7% of their weight, compared with those receiving a placebo, the FDA said.

Forty-seven percent of people without type 2 diabetes lost at least 5% of their weight, compared to 23% of those on placebo. Among patients with type 2 diabetes, 38% lost at least 5% of their weight compared to 16% who took the dummy pill, the agency said.

Overall, more patients taking Belviq lost weight than patients taking a placebo, the FDA said, and the drug was also "associated with favourable changes in glycemic [blood sugar] control in those with type 2 diabetes."

Heart valve function was found to be similar between those taking Belviq and those on placebo, the FDA added.

Counselling and support

Samantha Heller, an exercise physiologist and clinical nutrition coordinator at the Center for Cancer Care at Griffin Hospital in Derby, Conn., said, "Obesity is often associated with alterations in endocrine function, metabolism, hormones that regulate appetite and more."

For many people struggling with weight, these disruptions in the balance of hormones and metabolism make it difficult to lose weight, she said. People may feel hungry all the time, fatigued or lethargic. Losing weight for people who are obese is rarely as simple as eating less, she added.

"If Belviq can actually help people begin losing weight, then it may be a great idea. However, it is important to note that in the studies, nutrition and exercise counselling, education and support were an integral part of the process," Heller said.

"People need to understand that lifestyle modifications are essential for successful weight loss, weight maintenance, and fitness programs. The weight loss reported in the studies is modest and the placebo group lost weight too, indicating that ongoing lifestyle counselling and support have a positive impact with and without medication," she said.

There are some issues with the drug, the FDA said. First, Belviq should be stopped if patients don't lose at least 5% of their weight within 12 weeks, since they're unlikely to benefit from taking the drug for any longer period of time.

Second, the drug shouldn't be taken during pregnancy, the agency said.

Possible side effects

Belviq may cause serious side effects, including "serotonin syndrome," particularly when taken with certain medicines that increase serotonin levels or activate serotonin receptors, such as drugs used to treat depression and migraine. The drug may also cause problems with attention or memory, the FDA said.

Other common side effects in non-diabetic patients include headache, dizziness, fatigue, nausea, dry mouth, and constipation. In diabetic patients, side effects can include low blood sugar, headache, back pain, cough, and fatigue, the FDA said.

The agency is requiring Arena to undertake six post-marketing studies to look for any problems with Belviq, particularly the risk for heart attack and stroke.

Another weight loss drug, Qnexa from Vivus Inc., is still awaiting FDA approval. An FDA advisory panel recommended approval in February.

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More information

For more on obesity, visit the U.S. National Library of Medicine.

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