(Updates with comment from Orexigen.)
NEW YORK -(Dow Jones)- Arena Pharmaceuticals Inc.'s (ARNA) stock rose 14% on optimism for its experimental weight-loss drug Lorcaserin, after an editorial in a medical journal raised questions about the need for more data from a potential rival treatment.
The article, in the Lancet, covers a successful study by rival weight-loss drug developer Orexigen Therapeutics Inc. (OREX), but the editorial raises questions of whether more data are going to be needed to fully assess the drug's safety. That is good news for Arena, because it has longer-term data, and the third company in the race to develop the latest crop of drugs, Vivus Inc. (VVUS), was recently snubbed by a U.S. Food and Drug Administration panel on concerns about not having enough data.
Shares of Arena closed Friday at $7.95, hitting their highest level in more than two years. Shares of Orexigen rose 9.5% to $5.20, on the publishing of its data in the journal. Vivus shares were up 2.3% to $5.66.
The editorial from Arne Astrup, a professor from the Department of Human Nutrition at the University of Copenhagen, highlights recent problems with weight-loss drugs, including those with Meridia, sold by Abbott Laboratories (ABT).
The drug was pulled from the market in Europe this year after a study indicated that people with certain health problems who took the drug had more heart attacks, strokes and other cardiovascular problems than those on placebo. In the U.S., the FDA required Abbott to put a stronger warning on the Meridia label.
"Experience with [Meridia] perhaps suggests that more data are needed to get a better overall assessment of cardiovascular risk of this otherwise promising combination therapy for obesity," he wrote of Contrave.
Contrave is a combination of two drugs already on the market, antidepressant bupropion and addiction-treating naltrexone. The study published in The Lacent wasn't new, as initial results were disclosed more than a year ago from the trials and full details were presented in October.
Although Dr. Astrup acknowledged that Orexigen's drug improved several cardiometabolic risk factors, including triglycerides, and HDL cholesterol, he questioned why there were no reductions in blood pressure and LDL cholesterol that would normally be seen in weight loss.
Regarding potential psychiatric side effects, he said that the data suggest they may be lower than those seen in the individual components, but that more analysis is needed to come to that conclusion.
"The development of drugs for the management of obesity has been hampered by too much focus on efficacy and too little attention on safety, which has led to a series of withdrawals of drugs from the market after serious adverse effects arose," Dr. Astrup wrote.
The concerns about the level of available data are similar to those raised by the FDA panel about Vivus' drug earlier this month. That panel voted 10 to 6 against recommending the drug's approval on concerns the data weren't strong enough for a drug that could be used by millions of patients indefinitely.
In response to the editorial, Dennis Kim, senior vice president of medical affairs at Orexigen, said that safety findings in the studies of Contrave are consistent with the components of the drug.
Dr. Kim stressed the more than "20 years of clinical experience and safety characterization of bupropion and naltrexone in the U.S. market, which gives Contrave its unique and advantaged position with regards to unforeseen risks."
"We appreciate that postmarket surveillance will be important for any drug in this area and plan to discuss with the FDA what that would entail," Dr. Kim said.
Despite the enthusiasm in Friday's trading of Arena shares, lorcaserin has its own set of concerns. The mechanism of lorcaserin is similar to fenfluramine, which was pulled from the market in 1997 and was used with the stimulant phentermine in the fen-phen combination that caused heart-valve problems.
Arena has conducted extensive clinical testing and no heart issues have emerged, but it hasn't studied the drug's use with phentermine. The drug is commonly used to treat obesity and some believe that its potential use in combination with lorcaserin will raise concerns from regulators.
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