Arena Obesity Drug Was Effective by ‘Slim Margin,’ FDA Staff Raises Rat Cancer Concern; Shares Tumble

the secondary benefits patients experienced when they lost weight. “The weight loss observed in the lorcaserin-treated groups was associated with improvements in systolic and diastolic blood pressure, lipoprotein lipid levels, fasting glucose and insulin levels,” the FDA staff said.

In terms of safety, the FDA summary said that 2.66 percent of patients who got a 10 milligram, twice-daily dose of lorcaserin in the Bloom trial had a heart valve issue, compared with 2.35 percent who took a placebo. Both groups of patients, those on the drug and the placebo, had a 1.99 percent incidence of heart valve defects in the other major Arena trial, known as Blossom, the FDA said.

About twice as many patients on the Arena drug had some sort of neuropsychiatric effect, with dizziness, fatigue, and abnormal dreams among the most common. FDA reviewers said there didn’t appear to be a higher rate of depression-related adverse events on the Arena drug. The FDA staff did bring up some rare adverse events that could come up at Thursday’s discussion.

“Memory impairment, disturbance in attention, amnesia and other cognitive-related adverse events were reported infrequently overall; however, three times more subjects treated with lorcaserin 10 mg [twice daily] reported these types of events compared with subjects treated with placebo,” the FDA staff said.

The FDA’s deadline to complete its review of the Arena product is October 22.

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.