Orexigen Therapeutics, Inc. (MM) (NASDAQ:OREX)
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5 Years : From May 2012 to May 2017
Orexigen Therapeutics Inc. (OREX) is planning to run a two-year trial of its experimental weight-loss drug Contrave if it gets approved by the Food and Drug Administration early next year.
The San Diego company is in a three-way race with Vivus Inc. (VVUS) and Arena Pharmaceuticals Inc. (ARNA) to bring the latest crop of diet pills to market, but the issue of safety and the amount of data on the drugs has loomed over the ongoing regulatory review of the drugs.
Arena's lorcaserin has been tested in multiple two-year clinical trials, and Vivus reported successful two-year results from a clinical trial of Qnexa earlier Tuesday. Both drugs have been rejected by FDA advisory panels largely on concerns about safety.
Dennis Kim, Orexigen's senior vice president of medical affairs, said two-year trials don't add a significant amount of safety information unless they included a huge number of patients. Most major side effects, such as those related to the heart and stroke, would begin to show signals in a year-long study.
The purpose of a longer trial is mostly to show the ability of a drug to sustain a patient's weight loss or, in Arena's case, to rule out a specific risk like heart-valve damage, he said on the sidelines of a UBS conference in New York Tuesday.
Contrave, in development with Takeda Pharmaceutical Co. (TKPYY, 4502.TO), is a combination of two drugs already on the market, antidepressant bupropion and addiction-treating naltrexone. The current clinical data, from four late-stage trials, doesn't exceed 56 weeks.
Orexigen's Chief Executive Michael Narachi said the company is learning a lot from the recent FDA panels on lorcaserin and Qnexa. He also has been watching the successful panel review of Alkermes Inc.'s (ALKS) Vivitrol, an injectable form of naltrexone, and the split decision on whether to leave Abbott Laboratories' (ABT) diet drug Meridia on the market.
Meridia is under FDA review because a large study on high-risk patients suggested the drug increased the risk of having a heart attack or stroke. The FDA has strengthened the warnings on the drug's label, and it has been pulled from the European market.
In preparation for the Dec. 7 panel on Contrave, Orexigen has been running mock panels, which it expects will focus on its risk-management strategy and the increase in blood pressure and heart rate that is attributed to buproprion.
Narachi said those side effects go away as patients stay on the drug and lose weight. The blood pressure benefits from Contrave are never as good as patients losing the same amount of weight on placebos, "but the portion of patients who could actually achieve that is tiny compared to the portion on Contrave," he said.
Dr. Kim noted that the company will face the challenge of translating the drug's effects on long-term cardiovascular risk and it hopes to discuss a number of specific strategies with the panel. Those could include a post-market patient registry or a large long-term trial like the study that ended up raising questions for Meridia.
Narachi said the company is working with the FDA on the risk management plan, so it isn't a "new idea" when the panel meets. It will include a proposal for a formal Risk Evaluation and Mitigation Strategy, or REMS, along with a weight-management and health program for patients that take the drug.
"We think we can thread that needle a little bit better than others have," Dr. Kim said.
-Thomas Gryta; Dow Jones Newswires; 212-416-2169; email@example.com