Vivus says obesity drug effective; shares soar

BOSTON (Reuters) - Vivus Inc (VVUS.O) said on Wednesday that patients who took its experimental obesity drug for a year lost significantly more weight than those who took a placebo, sending the company's shares up nearly 80 percent.

The Mountain View, California-based company said a trial of 1,267 morbidly obese patients treated with its drug, Qnexa, lost an average of 37 pounds, or 14.7 percent of their body weight. That compared with a body weight loss of 2.5 percent for patients taking a placebo.

A second year-long trial of 2,487 obese patients with other conditions such as diabetes, showed those who took Qnexa had an average weight loss of 30 pounds, or 13.2 percent of their body weight, compared with a percentage weight loss of 2.4 percent for the placebo group.

Patients who took a lower dose of the drug lost 24 pounds, or 10.5 percent of their body weight.

The results met the requirements of the late-stage trials and will form the basis of a marketing application with U.S. regulators later this year.

Leland Wilson, the company's chief executive, told analysts on a conference call that the company will immediately enter partnership discussions with big pharmaceutical companies.

Qnexa combines relatively low doses of the generic stimulant phentermine and epilepsy drug topiramate, which is sold under the brand name Topamax. It is a capsule designed to release the components in way timed to minimize side effects.

Phentermine, a commonly prescribed weight loss drug, was part of the infamous fen-phen diet drug cocktail. Two other drugs used in the cocktail were recalled after they were linked with cardiovascular damage.

Side effects in the Qnexa trials included dry mouth, tingling, constipation, altered taste and insomnia.

Importantly, episodes of moderate to severe depression were less than 2 percent, in line with those for patients taking a placebo. The company said there were no suicide attempts or suicidal thoughts or behaviors -- a side affect that has hurt some other weight loss drugs.

Vivus said that the weight loss achieved was accompanied by a substantial improvement in key heart risks such as hypertension, diabetes and elevated triglycerides, which are a type of body fat.

Positing a hypothetical example of what patients might expect from Qnexa, Vivus said a typical 51-year-old female weighing 250 pounds would lose 37 pounds, reduce her blood pressure and risk for diabetes, increase good cholesterol by 21 percent and reduce bad cholesterol by 18 percent.

Vivus is competing with Arena Pharmaceuticals Inc (ARNA.O) and Orexigen Therapeutics Inc (OREX.O) to develop a viable therapeutic option for treating obesity.

A recent study, carried out in part by the U.S. Centers for Disease Control and Prevention, found that obesity-related diseases account for nearly 10 percent of all medical spending in the United States, or an estimated $147 billion a year.

Vivus's shares rose as high as $12.31 in early trading on Nasdaq.

(Additional reporting by Esha Dey and Deena Beasley; Editing by Ratul Ray Chaudhuri)

(Reporting by Toni Clarke, edit8ing by Dave Zimmerman)