By Thomas Gryta Of DOW JONES NEWSWIRES NEW YORK -(Dow Jones)- Arena Pharmaceuticals Inc. (ARNA) and Eisai Co.'s (ESALY, 4523.TO) weight-loss drug lorcaserin helped diabetic patients lose weight, according to recent data, but it is unclear if the findings are strong enough to help the drug get regulatory approval. The data, from a 600-patient study, comes after the Food and Drug Administration declined to approve lorcaserin in late October with a request for more information about cancer incidence in rat studies and additional data on lorcaserin's effectiveness. The agency called lorcaserin's weight-loss in previous studies "marginal" and Arena recently warned that such drugs tend to be less effective in the diabetes population. The latest year-long data show that 37.5% of patients taking lorcaserin twice a day achieved at least 5% weight loss, more than double the 16.1% of those taking placebo. Patients taking lorcaserin had mean weight loss of 4.5%, compared to 1.5% for placebo. The data meets one of the FDA's two guidelines for clinical trials of obesity treatments; only one of the goals must be met. Under the rules, at least 35% of the drug group must lose at least 5% of body weight, but that group must be double the percentage of patients with similar weight loss on the placebo. Alternatively, a study can show that patients had an average weight loss that was at least five percentage points higher than the placebo group's loss. Arena has said it will submit the data to the FDA. It plans to request a meeting with the agency and hasn't provided a timeline for refiling its marketing application. The company may need to conduct more clinical trials, possibly delaying any approval for years. An FDA panel recommended against the approval of lorcaserin in September. At the meeting, numerous members of the committee questioned whether the drug had been studied in a wide enough population and warned that the diabetes study was likely too small to measure the benefit/risk profile of the drug in that population. In the study, lorcaserin patients achieved a 0.9% reduction in a blood-sugar benchmark known as HbA1c, compared to a 0.4% reduction from placebo. Patients on the drug also achieved improvements in fasting glucose, HDL cholesterol and triglycerides. After a year, 2.9% of lorcaserin patients reported a new problem related to their heart valves, compared to 0.5% of placebo patients. The company said the trial wasn't designed to detect meaningful differences in the problem, called valvulopathy. Although the FDA panel didn't raise the issue, the issue of heart valve safety is notable for lorcaserin because the mechanism of the drug is similar to that of fenfluramine, which was pulled from the market in 1997 and was used with the stimulant phentermine in the fen-phen combination that caused similar problems. Arena has conducted extensive clinical testing and no heart issues have emerged. Arena is in a three-way race with Orexigen Therapeutics Inc. (OREX) and Vivus Inc. (VVUS) to sell a new weight-loss pill. Vivus' Qnexa was rejected by an FDA panel in July and the larger FDA declined to approve it in late October. The company is confident that it has sufficient data to meet the agency's needs and will file a formal response in coming weeks. Orexigen's Contrave, in development with Japan's Takeda Pharmaceutical Co. (TKPYY, 4502.TO), goes before an FDA panel in December with a decision expected in January. The route to approval for diet pills has proven difficult, as the drugs would likely be taken by millions of people, many of whom don't have any current health problems. Obesity is widespread and a risk factor for many serious health issues, but the FDA is reviewing the drugs on the assumption that they would be used indefinitely and has put a high bar on safety. -By Thomas Gryta, Dow Jones Newswires; 212-416-2169; thomas.gryta@dowjones.com
