Orexigen Therapeutics Inc. said Monday that in three large late-stage studies its obesity-drug candidate Contrave met its main goals and also surpassed a Food and Drug Administration requirement for effectiveness. The San Diego-based company said it plans to seek FDA approval for Contrave in early 2010.

The studies tested Contrave32, which combines bupropion, a drug used against depression and smoking habits, with naltrexone, which is used to fight alcoholism and opiate addiction. Orexigen CEO Mike Narachi said the drug "targets behavior and reward pathways in the brain."

The three trials each lasted 56 weeks. The non-diabetes trials involved 1,742 patients and 1,496 patients, respectively, while 505 people with type 2 diabetes participated in the third trial.

The trials showed patients who took Contrave reported significantly greater weight loss than those who took a placebo. The company said the drug reduced other risk factors like waist circumference, and in the case of diabetes patients, the drug also reduced blood sugar levels.

Dennis Kim, who leads Orexigen's obesity and metabolic-disorders unit, said Contrave is "the first drug I'm aware of that addresses cravings in terms of obesity." Contrave also reportedly tempered food cravings and allowed patients to better control their eating.

Two trials were conducted with non-diabetic patients and Orexigen said 48% and 56.3% of patients, respectively, reported weight loss of at least 5% as compared to 16.4% and 17.1% for the placebo patients.

One of the three trials tested the drug in diabetes patients, which showed Contrave being effective in helping them lose weight and showed a reduction in a measurement of blood-glucose levels. Mean weight loss in the diabetes trial was 5.9%, or 13.5 pounds, compared with 2.2%, or 5.1 pounds.

As per FDA requirements at least 35% of the patients involved must lose at least 5% of their body weight and at least double the patients must reach the 5% goal compared with those who take a placebo. All three Contrave trials met the first guideline, with one meeting the second guideline as well.

Orexigen said the drug reduced risk factors including waist circumference, midsection fat and triglycerides and improved levels of "good" HDL cholesterol.

Orexigen shares in early trading, rose $1.80 to $7.49.

"I think it should be very reassuring to investors," Narachi said. "Our clinical trial program is completed, and there is nothing else to look at."

On the issue of side effects Orexigen highlighted that in the trials Contrave had minimal side effects with the most common issue being mild to moderate nausea, which was described as "transient and manageable," constipation and headache.

Rivals, Arena Pharmaceuticals Inc. and Vivus Inc., are also trying to bring their own obesity drugs to market. Orexigen said it is filing for FDA approval on its own, but is looking for a partner to bring Contrave to the primary-care market and to overseas markets.