The drug lorcaserin, marketed under the brand name Belviq, is a weight loss drug developed by two companies: Arena and Eisai Co. Ltd. It was designed to activate certain serotonin receptors in the brain in order to reduce appetite. In early 2020, the Food and Drug Administration requested that the manufacturer recall the drug because clinical trials showed an increased occurrence of cancer, and that the risks of the drug outweigh the benefits. These clinical trials took place over the span of many years, and during the three and five year checkups on the patients it was shown that 7.7% of the subjects developed cancer, with an increase in certain types like pancreatic, colorectal, and lung cancer.
With this study, all participants (12,000 of them) were either overweight or considered obese. Additionally, they were either already prone to cardiovascular disease or were 50 years or older with type 2 diabetes and other cardiovascular risk factors. The groups were divided into those that were taking Belviq and those who were taking a placebo. The 7.7% who developed cancer from taking Belviq (462 people) were diagnosed with 520 primary cancers, compared to 7.1% of the placebo group who were diagnosed with 470 primary cancers. It was also found that the longer someone took the drug led to an increased risk of developing cancer. This increase was significant enough for the FDA to intervene.
For those who were taking Belviq it was recommended that they speak to their physician and to seek out a different type of weight loss drug. And generally speaking, it is safe to stop taking a weight loss drug, so patients were not necessarily at an immediate risk of withdrawals or other harmful side effects from going off of it. At the same time, being that it interacts with serotonin, Belviq is known to produce dependence if taken in incorrect dosages. It might also be difficult to find a drug that works on these receptors in the same way to reduce appetite, since it produces an artificial sense of being full.
At this point, there are no class action lawsuits against the companies involved, but individual lawsuits have been filed across the country. In October 2021, there were roughly 30 Belviq cancer lawsuits filed in federal courts on the basis that Eisai had knowingly distributed a drug that was unsafe, and without adequate warning about the cancer risks. If you are experiencing side effects from Belviq, you can file a notice with the FDA through this link (https://www.accessdata.fda.gov/scripts/medwatch/index.cfm).