Belviq Cancer Warnings Came Long After Safety Signals in Clinical Trial

Months before federal regulators announced a Belviq recall, data from a study suggested that side effects of the weight loss drug may increase the risk of cancer, but the findings were buried within a key clinical trial.

In July 2019, an expert analysis of the CAMEILLIA-TIMI 61 Trial was published by the American College of Cardiology. The study looked at the effectiveness and side effects of Belviq, including the largest concern at the time: cardiovascular risks.

While not publicly announced until months later, the data contained concerning indications about a potential link between Belviq and pancreatic cancer, colorectal cancer and lung cancer. However, the FDA did not issue Belviq cancer warnings until January 2020, and several weeks later it was determined that the weight loss drug needed to be removed from the market.

Lorcaserin, marketed under the brand name Belviq and Belviq XR, was first approved by the FDA in 2012, as a prescription weight loss drug for adults who are obese or who have weight related medical problems that prohibit them from losing weight through traditional diet and exercise. The active ingredients of the pill are intended to trigger chemical signals that make people want to eat less.

Belviq and Belviq XR are manufactured by Japanese drugmaker Eisai Co. who began selling the medication in the U.S. in 2013. The medication quickly became a popular choice among prescribing doctors, with more than 600,000 prescriptions filled in 2015 alone, with sales reaching an estimated $50 million.

Despite pre-market testing that suggested Belviq exposure in rats could cause cancerous tumors, the FDA approved Eisai to start promoting the drug. However, the manufacturer was required to conduct a randomized, double-blind, placebo-controlled clinical trial in order to determine if there were any cancer or cardiovascular side effects in humans from Belviq.

The findings of that five year trial were published in July, outlining the data after following 12,000 overweight or obese patients with atherosclerotic cardiovascular disease or multiple cardiovascular risk factors, who were given either 10 mg of Belviq twice daily or a placebo.

When the study was published, it focused on whether using Belviq caused additional heart risks, whether it decreased the risk of diabetes, and other potential adverse effects, like hypoglycemia. However, the data found that about 7.7% of Belviq patients had cancer diagnoses, compared with 7.1% of patients who got a placebo, raising alarms months later within the medical community.

Patients who were prescribed Belviq were found to be more frequently diagnosed with several types of tumors, including pancreatic, colorectal and lung cancers, according to the FDA recall notice issued on February 13.

This suggests that Belviq stayed on the market for about six months after the data suggesting an increased cancer risk was available to the manufacturer. Additionally, it was a five-year study, questions are now being raised about when the manufacturer should have identified the increased incidence of cancer among Belviq users, and whether earlier warnings could have prevented many cases of cancer now being diagnosed.

Since the strongest sales for Belviq have been over the past few years, it appears likely that many cases of pancreatic cancer, colorectal cancer, lung cancer and other cancers could have been avoided if information about the risks associated with the weight loss drug had been provided to users and the medical community.

The questions are likely to be raised in a growing number of Belviq lawsuits that may be filed in the coming months and years, including class action claims that seek refunds and medical monitoring for those who were unnecessarily exposed to the weight loss drug.