WASHINGTON (By Susan Heavey) - Orexigen Therapeutics Inc's Contrave, the last of a trio of new weight-loss drugs, can effectively help patients shed pounds, the biotech company told a panel of U.S. medical advisers on Tuesday at a meeting set to focus on heart risks.
Company officials are facing a Food and Drug Administration panel of outside advisers who have already rejected two competing diet drugs this year and are likely to have tough questions about the pill's effect on blood pressure and pulse rates, among other safety concerns.
Shares of Orexigen have fallen 36 percent this year as investors worry whether the biotech can succeed where rivals have failed, aiming to tap into a potentially major market in the United States, where rates of obesity continue to soar.
Drugmakers seeking a pill to help people slim down have been thwarted for decades by serious side effects, and few options remain on the U.S. market even though two out of three Americans are overweight or obese.
In October, the FDA rejected two rival pills from Arena Pharmaceuticals Inc and Vivus Inc.
Dawn Viveash, head of regulatory affairs for Orexigen, said the company was "aware of the challenges" of trying to bring a new diet drug to market but that it had learned from its rivals' fates.
"The road has been long and hard both for individual drugs as well as for the class," Viveash told the panel, which will offer its recommendations on the proposed pill later Tuesday. Final votes are expected by 5 p.m. EST (2200 GMT).
Approval is key to California-based Orexigen, which focuses solely on obesity drugs and has no products on the market yet.
According to data from BioMedTracker, Contrave sales could reach $1.2 billion by 2018. That figure would make it the top player in a U.S. weight-loss drug market that sees just $382 million annually, according to IMS Health.
Contrave combines the alcohol and drug addiction drug naltrexone and the antidepressant bupropion in an attempt to boost metabolism while curbing appetite and cravings.
Orexigen, which has partnered with Takeda Pharmaceutical Co Ltd to help market its Contrave pill if approved, told panelists combining two already-approved drugs was an advantage because many safety issues are already known.
Although the pill meets FDA effectiveness guidelines, in that at least 35 percent of patients studied lost at least 5 percent of their weight, FDA staff have concerns.
Eric Colman, deputy director of the FDA division that oversees weight loss and other related drugs, asked the panel to consider possible seizure risks and suicidal behavior.
Panelists should pay close attention to the drug's effect on the heart, he said, adding, "This is probably the more important issue we'll be discussing today."
MODEST WEIGHT LOSS ENOUGH?
Analysts say Orexigen's approval chances hinge on its ability to show that Contrave's risks are manageable.
Orexigen told panelists modest weight loss can have a notable effect on patient health by reducing the risk for chronic diseases linked to obesity such as diabetes.
It said changes in blood pressure and pulse rates in 2,545 patients given Contrave in clinical trials were similar to the 1,515 given a placebo.
Any clinical trial taking a closer look at heart risks should be done after approval, company representatives argued, saying it would have to study tens of thousands of patients over several years.
Patients given Contrave experienced psychiatric events such as sleep disorders and anxiety, but not suicide or depression, company officials added.
Another issue likely to arise at the meeting is whether the company's 12 months of data is sufficient, given that Orexigen is seeking approval for long-term use.
Diet and exercise are proven to help people shed pounds, but some say such efforts can be so difficult that drugs or other options like surgery are needed. Critics say policy changes targeting foods, public transportation, and other lifestyle changes are needed more than new pills.
Caroline Apovian, head of the Nutrition and Weight Management Center at Boston University's Boston Medical Center and an Orexigen consultant, pointed to another FDA panel's backing last week to allow less obese patients access to Allergan's Lap-Band surgery.
"Additional treatment options are needed," especially medicines, said Apovian, who also consults for Allergan.
Shares of Orexigen were halted pending the panel's vote. The FDA is expected to make a final decision by January 31.
(Reporting by Susan Heavey; Editing by Tim Dobbyn, Dave Zimmerman)
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