Arena Pharmaceuticals, Inc. Skimps On Data Disclosure From Weight-Loss Combo Study: Analyst

October 30, 2014

By Riley McDermid, BioSpace.com Breaking News Staff

Arena Pharmaceuticals is under fire Thursday after Wall Street analysts and market watchers complained that the company has skimped on data about its new weight loss combination of Belviq and phentermine.

Although Arena’s statement disclosing results of a recent 12-week study said obese patients did not report higher report higher rates of “headache, dizziness, nausea, fatigue, dry mouth, diarrhea, vomiting, insomnia or anxiety compared to patients treated with Belviq alone,” the company did not disclose any information about possibly adverse cardiac events.

The new drug, dubbed Bel-phen, is under close scrutiny because weight loss drugs of its type have in the past caused damage to heart valves, particularly when combined with phentermine. Additional details are likely to be presented at the Obesity conference in November.

Arena has been careful to stress throughout its development that Belviq would avoid the pitfalls experienced by wildly popular and sometimes-fatal previous drug of fenfluramine, but today’s disclosure left few comforted that it is a safer alternative.

“Doctors still cite the potential for safety risks as a reason not to prescribe Belviq to their patients, which has contributed to the drug's dismal sales to date,” wrote Adam Feuerstein on his popular biotech blog.

“Theoretically, the combination of Belviq and phentermine may help patients lose more weight than Belviq alone, but the added risk of causing heart damage, if any, hasn't been quantified,” he said. “The current combination study is too small and too short to answer the heart-safety question.”

Japanese drugmaker Eisa markets Belviq is marketed in the U.S and reported sales of $18.3 million for the first two quarters of 2014. Under a revenue-sharing agreement, with Arena received $6 million of that profit.