Pharmaceutical company Zafgen has decided to halt development of its main drug candidate beloranib, designed to treat obesity related to Willi-Prader syndrome, following a meeting with the Food and Drug Administration (FDA). The agency had placed a hold on the clinical development of beloranib in December after two patients died from pulmonary embolism related to the treatment.
Prader-Willi Syndrome is a rare genetic disorder that causes constant, extreme hunger often resulting in life-threatening obesity. Beloranib was designed to make the body produce less fat and burn off excess fat as fuel by blocking methionine aminopeptidase 2, an enzyme that plays a key role in the production and use of acids.
Beloranib was designed primarily as a treatment for Prader-Willi Syndrome, but Zafgen was also testing it as a treatment for other weight-related disorders. One patient in the Prader-Willi Syndrome arm died from bilateral pulmonary emboli. There were also reports of thromboembolic events, or potentially life threatening blood clots in the blood vessels, in patients in other studies on the drug.
“Following its discussions with the FDA and review of other considerations, Zafgen has determined that the obstacles, costs and development timelines to obtain marketing approval for beloranib are too great to justify additional investment in the program, particularly given the promising emerging profile of ZGN-1061,” a treatment for a more generalized form of obesity, the company stated in its press release.
News of the discontinuation of the development of beloranib comes as a particular blow to the Willi-Prader community because of the lack of treatments available for patients with the disorder. Currently, the only treatment is human growth hormone (HGH).