A study published in the May 2014 issue of the French medical journal La Revue Prescrire warned that the prescription diet pill lorcaserin, known by the brand name Belviq, was risky. The U.S. Food and Drug Administration (FDA) had approved it just two years earlier. But European regulators were wary.
In 2013, drug maker Eisai withdrew Belviq’s application for marketing in Europe after the European Medicines Agency (EMA) indicated it was unlikely to be approved there because of studies on laboratory animals that showed a potential cancer risk. It was especially concerning since Belviq was intended to be a long-term treatment for obesity, increasing the likelihood of adverse effects.
Still, the FDA allowed Belviq to be marketed in the U.S. One condition was that Eisai had to conduct long-term studies to determine whether Belviq increased the risk for heart attacks and strokes. (The FDA had been burned in the past by the notorious fen-phen obesity treatment that was quickly pulled from the market after it was linked to unusual, serious, and potentially deadly heart valve problems.)
The Prescrire review found “no justification for exposing patients to the risk of adverse effects” associated with Belviq, which were reported as mainly gastrointestinal (dry mouth and nausea) and neuropsychiatric (dizziness, fatigue, headache, and euphoria). But researchers found that the clinical trials, which only involved about 6,000 patients, were “too short in duration to exclude a risk of cancer (breast cancer and astrocytoma) that was reported in experimental animals.”
Another concern was that a large proportion of study participants — about 40% to 50% — were lost to follow-up before the trial ended. Furthermore, the weight loss of participants treated with Belviq was only about 6 pounds higher on average compared to study participants treated with a placebo — a difference the author found did not justify the risks.
The incidence of cardiac valve disorders was also higher among Belviq users compared to those given a placebo. But the long-term studies Eisai recently produced didn’t show much difference between the two groups.
What the Belviq study did show is that users of Belviq had a higher occurrence of cancer compared to patients not taking Belviq. The cancers most often reported among Belviq users included pancreatic cancer, colorectal cancer, and lung cancer. The FDA said the incidence translated to about one additional cancer diagnosis per 470 Belviq users per year. It was worrisome enough that on Feb. 13, 2020, the FDA called for the withdrawal of Belviq and Belviq XR from the U.S. market.
If you or a loved one has taken Belviq and been diagnosed with cancer, we would like to talk with you. Roger Smith, Ryan Duplechin and Melissa Prickett, attorneys with Beasley Allen Law Firm, are currently investigating individual cases of pancreatic cancer, colorectal cancer and lung cancer in patients who have been treated with Belviq.