On Tuesday, the LaJolla, Calif.-based developer of a drug it calls Contrave tries to succeed where at least three other pharmaceutical firms have failed in recent years -- to win over a panel of independent experts advising the Food and Drug Administration on new weight-loss drugs.
Orexigen Therapeutics Inc. will tell the FDA advisory panel on metabolic and endocrinological drugs that in four different clinical trials, subjects taking Contrave -- a combination of the antidepressant bupropion and the anti-addiction drug naltrexone -- lost more weight than did those taking a dummy pill.
But in a memo that sets out the committee's task, FDA staffers underscore that Contrave just barely satisfied the principal standard of effectiveness the agency laid out in 2007 as a benchmark for judging diet drugs, and warned that Contrave has the potential to raise blood pressure in many who take it.
The FDA staff's memo, posted to the FDA website ahead of Tuesday's meeting, notes that in four clinical trials with a total of roughly 4,500 overweight and obese subjects, the weight-loss differences between those taking Contrave and those taking a placebo for roughly a year were "of nominal statistical significance." But the proposed diet drug did satisfy a backup measure of adequate effectiveness the FDA said it would consider: in all four trials, more than a third of subjects lost a total of at least 5% of body weight while taking Contrave. In one of the four, two-thirds lost more than 5% of their body weight, and on average, roughly half did in the other trials.