(HealthDay) -- A new combination treatment of controlled-release phentermine/topiramate (PHEN/TPM CR) leads to significantly greater weight loss than a placebo even in individuals with significant obesity-related comorbidities, according to a study presented at the European Congress on Obesity, held from May 9 to 11 in Lyon, France.
Stephan Rössner, M.D., Ph.D., from the Karolinska Institutet in Stockholm, and colleagues randomly assigned 2,487 subjects to placebo or one of two doses of PHEN/TPM CR: 7.5 mg/46 mg (7.5/46) or 15 mg/92 mg (15/92) for 56 weeks. Subjects were categorized according to the Edmonton Obesity Staging System (EOSS), which measures obesity-related morbidity, with most subjects having weight-related chronic disease (2,170 individuals) or established end-organ damage (180 individuals).
The researchers found that PHEN/TPM treatment was associated with significantly greater weight loss compared with placebo across all EOSS categories. Weight loss increased in a dose-response manner and ranged from 1.5 to 2.3 percent for placebo, 6.8 to 8.6 percent for 7.5/46 PHEN/TPM, and 9.5 to 10.5 percent for 15/92 PHEN/TPM. Dry mouth, constipation, and paraesthesia were the most common adverse events.
"In this study, subjects with established comorbidities treated with PHEN/TPM CR showed significantly greater weight loss than placebo regardless of baseline EOSS," Rossner and colleagues conclude.
Several authors disclosed financial ties to pharmaceutical companies, including Vivus, which manufactures phentermine/topiramate and funded the study.