Using sibutramine or phentermine in tandem with pramlintide can enhance weight loss

Amy Halseth, MD, Amylin Pharmaceuticals, San Diego, California, and colleagues randomised 244 overweight or obese patients after a 1-week placebo run-in period to 24 weeks of subcutaneous injections of placebo or pramlintide 120 mcg TID alone or in combination with sibutramine 10 mg QAM or phentermine 37.5 mg QAM. Participants also received dietary counselling.

Pramlintide combined with sibutramine produced an 11.3 +- 1.2 kg mean weight loss, while pramlintide coupled with phentermine produced an 11.3 +- 0.9 kg mean weight loss. Subjects treated with pramlintide alone lost a mean of 3.6 +- 0.7 kg, and placebo-treated patients lost a mean of 2.1 +- 0.9 kg (P < .0001 combination arms vs pramlintide or placebo).

More patients achieved 5% or greater weight loss and 10% or greater weight loss in the pramlintide-sibutramine (78% and 49%, respectively) and pramlintide plus phentermine (82% and 56%, respectively) groups than pramlintide (36% and 11%) or placebo treatment groups (28% and 3%, respectively).

Three serious events occurred -- 2 with placebo, 1 with pramlintide plus phentermine. None of these events was judged to be related to the study medication. The most frequently observed adverse events were similar to those that have been previously reported with these agents when used individually, and no novel safety or tolerability issues arose with either medication, according to the researchers.

The robust weight loss (about 11% from baseline) with pramlintide plus sibutramine and pramlintide plus phentermine seen in this study confirms the potential for the development of combination treatment for obesity, Dr. Halseth said in a presentation on September 9.

She also noted that the findings corroborate earlier experimental data suggesting that targeting multiple pathways using the combination of pramlintide and other centrally-acting agents may produce robust weight loss.

Finally, she noted that future studies should assess more fully the potential risks of combination therapies in future studies.

Source: Doctor's Guide