Low-dose Qnexa: 3.75 mg Phentermine plus 23 mg Topamax causes weight loss of 5.1% vs 1.6% w/placebo

By Larry Hobbs
Wednesday, September 09, 2009

Morbidly obese patients given the lowest dose of Qnexa, containing 3.75 mg of phentermine plus 23 mg of Topamax (topiramate), lost an average weight loss of 18 pounds versus 6 pounds with placebo after one year, or 5.1 percent of body weight versus 1.6 percent with placebo according to a press release from press release from Vivus, Inc, the company developing the drug.

Weight Loss for Those Who Completed the Study

Weight Loss for Those Who Completed the Study : 7% vs 2.5%

Forty-seven percent (47 percent) of those given the low-dose Qnexa completed the entire one-year study.

The average weight loss for these patients was 7 percent of body weight versus 2.5 percent of those given the placebo who completed the study.

Subjects

Subjects: 1267 morbidly obese patients

The study, which was called the EQUIP (OB-302) study, involved “1,267 morbidly obese patients (1,050 females and 217 males) across 93 centers in the United States” the press release notes.

The number on each dose of the drug was as follows:

• 498 on placebo
• 234 on Low Dose Qnexa (3.75 mg phentermine / 23 mg controlled release topiramate (Topamax))

BMI

Starting BMI: 42

The average starting body mass index (BMI) was 42.1.

Dose

Dose slowly increased over one month

The dose was slowly increased (titrated) over four weeks.

Diet

Diet: Patients suggested to reduce calorie intake by 500 calories per day

Patients were asked to follow a diet that was reduced by 500 calories per day.

Conclusion

Conclusion: Weight loss with drug combination exceeds other agents

“The weight loss observed with Qnexa in these two one-year, double-blind, randomized trials far exceeds the weight loss observed for other agents reported in literature,” said Kishore Gadde, MD, director of obesity clinical trials at Duke University and a lead investigator.

REFERENCE

Vivus. Vivus announces positive results from two phase 3 studies; obese patients on qnexa achieve average weight loss up to 14.7% and significant improvements in co-morbidities.

Press Release from Vivus Inc. 2009 Sept 09, http://ir.vivus.com/releasedetail.cfm?ReleaseID=407933.