UPDATE:  This study was terminated. Zafgen has decided to cease development of Beloranib due to high risk of thrombotic events.  See the letter from Zafgen to the PWS community.

Zafgen is sponsoring a Phase III, double blind, placebo controlled study of Beloranib in overweight or obese adolescents and adults (12 and over) with PWS to evaluate safety and efficacy of the investigational drug over six months.  Zafgen will test whether Beloranib may change the way the body metabolizes fat, and the study will test whether it is effective in reducing fat mass and decreasing hyperphagia (excessive hunger) in PWS.  There are fourteen study sites across the US open and recruiting including CA, CO, FL, KS, MA, MD, MN, MO, NY, OH, TN and TX.  Canadian citizens are eligible to participate at US sites.  Zafgen will assist families with travel expenses, and all participants who complete the first six months of the study, including those who initially receive placebo, will have the opportunity to receive beloranib for an additional six months if they so choose.