Orexigen's Diet Pill Victory at Panel Shows Benefit of Being Last at FDA
Orexigen Therapeutics Inc.’s success in winning the first U.S. panel recommendation for a long-sought prescription diet pill led its shares to almost double and shows the company benefited from its rivals’ earlier difficulties.
Outside advisers to the Food and Drug Administration said weight-loss benefits of Orexigen’s product, Contrave, exceed the dangers of elevated pulse and blood pressure and that a large study on cardiovascular risk can wait until after the drug is approved. The FDA delayed competing treatments from Arena Pharmaceuticals Inc. and Vivus Inc. in October after they failed to win panel backing on safety.
“The fact that they were able to convince the panel not only that the cardiovascular study can wait, but that the drug can be approved, is exciting, particularly after we saw the other obesity drugs voted down,” Joshua Schimmer, a Leerink Swann analyst, said yesterday in a telephone interview. “It’s hard to know to what extent their strategy was altered by the first two, but it sure as heck didn’t hurt.”
While the FDA isn’t obliged to follow recommendations of advisers, their support eases concern that had caused Orexigen shares to drop more than a third this year. The La Jolla, California-based company gained from watching the FDA’s safety focus and saw that a commitment to minimize risks and conduct more studies would be needed for approval, Schimmer said.
Orexigen rose $4.01, or 84 percent, to $8.77 at 4 p.m. New York time in Nasdaq Stock Market composite trading, the most in a single day since the shares began trading in April 2007. Options traders placed record bets on Orexigen last week, saying a positive panel vote would double the company’s value. Vivus shares gained $1.20, or 15 percent, to $9 as analysts said the Orexigen recommendation suggests the long-term heart risks with Vivus’s drug, Qnexa, won’t need to be studied before approval. Arena jumped 16 cents, or 11 percent, to $1.57.
About 68 percent of American adults are overweight, raising their risk of diabetes, heart disease, high blood pressure and cancer, according to the 2008 National Health and Nutrition Examination Survey. Almost 34 percent are obese, measured as a ratio between height and weight.
The three companies and their partners have been in a race to introduce the first prescription weight-loss pill in more than a decade. Basel, Switzerland-based Roche Holding AG’s Xenical, approved in 1999, is the only long-term medicine for weight loss since Abbott Park, Illinois-based Abbott Laboratories’ Meridia was pulled off the market in October because of heart risks.
Orexigen and partner Takeda Pharmaceutical Co., of Osaka, Japan, are scheduled to receive a decision from the FDA by Jan. 31. Schimmer said approval may be delayed while the company and the agency work out details of the prescribing information and the new study. He expects Contrave and Qnexa ultimately to win approval with potential sales of each reaching $1 billion or more in the U.S.
“We learned about the complex issues surrounding obesity therapeutics that are important to the FDA and the medical community, and we did our best to address those issues,” Orexigen Chief Executive Officer Michael Narachi said yesterday after the vote.
Vivus, based in Mountain View, California, said Oct. 29 that it plans to respond within six weeks to the FDA’s request for more information about heart risks and birth defects linked to Qnexa. This would trigger a new two- to six-month review.
“Vivus is encouraged by Tuesday’s advisory committee meeting because it provides hope for patients that new medical treatments for obesity are seriously being considered by the FDA,” the company said today in an e-mail.
San Diego-based Arena said Oct. 25 that the FDA had questions about tumors seen in studies of rats taking the diet drug lorcaserin, which Arena is developing with Eisai Co. of Tokyo. The companies will meet with the agency later this month.
“Arena is pleased to see the recognition of the need for obesity medications,” the company said in an e-mail today. “At this time, the company is focused on obtaining FDA approval of lorcaserin as quickly as possible.”
Contrave, Orexigen’s first product, is a combination of two approved drugs that target different parts of the brain that influence appetite and cravings. The pill contains bupropion, an antidepressant also used to quit smoking, and naltrexone, a treatment for alcohol and painkiller addiction.
Two tablets of Contrave twice a day helped twice as many patients in studies lose at least 5 percent of their weight compared with a placebo after 56 weeks. The drug missed the FDA’s second standard of effectiveness in failing to show at least a 5 percent benefit over placebo. Patients on the drug also had higher pulse and blood pressure than patients on placebo, even after losing weight.
Dissident members of the advisory panel said Contrave shouldn’t be approved without a large study of heart risks because it counteracts some of the expected benefits of weight loss, a signal that it may have long-term complications.
“This drug resembles sibutramine,” said panel member Sanjay Kaul, using the chemical name for Meridia. “There is an opportunity for us to learn from history or else we’re going to repeat it. We need to make sure we get it right this time.”
Kaul is the director of fellowship training in cardiovascular diseases at Cedars-Sinai Medical Center in Los Angeles.
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