Zafgen, a Boston-based biopharmaceutical company dedicated to significantly improving the health and well-being of patients affected by obesity and complex metabolic disorders, has received verbal notice from the FDA that its beloranib investigational new drug (IND) application has been placed on complete clinical hold, affecting the ongoing open label extension (OLE) portion of the pivotal phase III ZAF-311 bestPWS clinical trial in patients with Prader-Willi syndrome (PWS). A complete clinical hold is an order that the FDA issues to a sponsor to suspend all clinical work requested under the company's IND application.

“We are working diligently to assemble and analyze the data from our ZAF-311 clinical trial to be able to provide a clear view of the safety and efficacy of beloranib in the PWS population,” said Dr. Thomas Hughes, chief executive officer of Zafgen. “Together with PWS and thrombosis experts, we are developing a comprehensive approach to better understand the incidence and mechanisms underlying thromboembolic disease in the setting of PWS. We remain committed to advancing beloranib as a potential new therapy for this underserved patient population.”

As previously announced, the company continues to expect top-line results of the randomized portion of the ZAF-311 clinical trial in the first quarter of 2016.

Beloranib is a novel, first-in-class injectable small molecule therapy with a unique mechanism of action that reduces hunger while stimulating the use of stored fat as an energy source. Beloranib is a potent inhibitor of MetAP2, an enzyme that modulates the activity of key cellular processes that control metabolism. MetAP2 inhibitors work, at least in part, by directing MetAP2 binding to cellular stress mediators, and, thus, reducing the tone of signals that drive lipid synthesis by the liver and fat storage throughout the body. In that manner, MetAP2 inhibition increases metabolism of fat as an energy source. Zafgen holds exclusive worldwide rights (exclusive of South Korea) for the development and commercialization of beloranib. Zafgen exclusively licensed beloranib from Chong Kun Dang Pharmaceutical (CKD Pharma) of South Korea.