Eisai is withdrawing weight-loss drug lorcaserin after a post-marketing study found a higher incidence of cancer in patients who took the medicine.
The FDA said Thursday that its request for removal of the product from the market is voluntary, but Eisai has already started the process for doing so. The withdrawal follows an FDA alert issued last month that lorcaserin may contribute to a higher risk of cancer.
Lorcaserin was approved in 2012 as a weight management therapy for use in addition to a reduced-calorie diet and exercise. The drug was intended to suppress appetite while avoiding risks of heart problems that have derailed other weight-loss drugs. The FDA approval required Arena Pharmaceuticals (NASDAQ: ARNA), which originally developed the drug, to conduct a double-blind, placebo-controlled study to assess the drug’s risk of contributing to cardiovascular disease.
The clinical trial enrolled 12,000 men and women who were overweight or obese. In the five-year study, patients were randomly assigned to receive either lorcaserin or a placebo twice daily. According to the FDA analysis, there was no meaningful difference between the treatment group and the placebo group in terms of cardiovascular risk. But the data showed a higher number of cancer diagnoses in the group that received lorcaserin. While that imbalance was not apparent in the initial months of treatment, it increased as patients continued to take the drug. The cancers that occurred more frequently in the loracaserin group included pancreatic, colorectal, and lung cancer.
Cancer, not cardiovascular risk, was one of the early concerns that stymied initial efforts to win FDA approval for lorcaserin. When Arena first submitted the drug to the FDA in 2010, the regulator’s review staff flagged a higher incidence of cancer in the company’s tests of the drug in rats. The doses given to the rats were higher than the dose proposed for humans, but those results still factored in the regulatory decision. When the FDA rejected the drug later that year Arena said that agency cited “marginal” effectiveness of the drug in clinical trials, as well as cancer risks observed in the rat studies.
Arena addressed the FDA’s concerns by conducting more clinical testing, providing enough data to support regulatory approval in 2012. But the company, along with Eisai as its commercialization partner, were unable to turn the weight-loss drug into a big seller. Commercialization challenges were not specific to lorcaserin. Obesity drugs from Orexigen Therapeutics and Vivus (NASDAQ: VVUS) have also struggled commercially. In 2017, Arena sold its lorcaserin rights to Eisai, which took over manufacturing and marketing of the drug.
The FDA says patients who are currently being treated with lorcaserin should stop taking the medication and discuss alternatives with a physician. Unused medication should be taken to a drug take back location; if one is not available, the pills can be disposed of in household trash mixed with dirt, cat litter, or used coffee grounds.