Weight loss drug shown to increase cancer risks

The U.S. Food and Drug Administration (FDA) announced Thursday the withdrawal of the prescription weight-loss drug Belviq after studies have shown links between the drug usage and cancer. 

According to the FDA's official press release, a randomized, placebo-controlled clinical trial to evaluate the risk of heart-related problems also revealed the increased risk of cancer with the weight loss drug. More patients taking the drug lorcaserin, marketed under the brand name Belviq, were diagnosed with cancer as compared to patients taking the inactive placebo, the trial found. 

In response to these results, the FDA requested that Belviq's manufacturer, the Japanese company Eisai, Inc., withdraw the drug from U.S. markets. The FDA reports that Eisai has complied and will voluntarily remove Belviq from shelves until further notice. The AP reports, however, that Eisai disagrees with the FDA's data analysis and that Belviq's "benefit outweighs the risk." 

The FDA recommends that people currently taking lorcaserin should immediately stop taking the drug and seek consultation from their health care providers about alternative options. The release said it is best to dispose of lorcaserin using a local drug-take-back location, but if that is not an option, to throw pills away responsibly, as outlined on the FDA's website.  

Health care professionals, meanwhile, are instructed to cease prescribing and dispensing Belviq and to contact any patients currently on it. So far, the FDA does not recommend any additional special screening for patients who have taken lorcaserin, but encourages standard screenings for cancer. 

The study was conducted with a population of 12,000 patients over the course of five years. Lorcaserin was initially approved by the FDA back in 2012, and, according to the AP, was the first weight-loss drug to help patients achieve sustainable weight loss without increased cardiovascular problems. This satisfied FDA conditions for Belviq and Belviq XR — the former a tablet and the latter an extended-release tablet — to be sold in U.S. markets. 

Between January 2014 and June 2018, the same randomized, placebo-controlled study that yielded low cardiovascular health risks also showed a "numerical imbalance" in cancers between patients who took lorcaserin and patients who took the placebo drug. 

During the course of the trial, the FDA reports that 7.7 percent of patients treated with lorcaserin were diagnosed with 50 primary cancers compared to the placebo group, who recorded a smaller 7.1 percent of patients diagnosed with 470 cancers.  

The FDA noticed that this disparity increased the longer patients took lorcaserin. Specific cancers that were frequently seen were pancreatic, colorectal and lung cancers. It did note that these risks are primarily seen with prolonged use of lorcaserin.

The FDA announced in January that it was reviewing clinical data after the agency was alerted of the drug's potential links to cancer.