Zafgen announces update on trials for beloranib following death of Prader-Willi syndrome patient in ZAF-311 trial

Zafgen learned of a patient death in the ongoing Phase III ZAF-311 clinical trial of beloranib in PWS, and it subsequently received notice from the FDA that beloranib has been placed on a partial clinical hold. Although the autopsy report remains to be received, the cause of death based on the death certificate has been determined to be respiratory failure due to pulmonary emboli. However, it is not known if this event was related to treatment with beloranib.

After review of its ongoing clinical trials, Zafgen has elected to proceed with efficacy and safety data analysis and close the randomised portion of its Phase III ZAF-311 clinical trial of beloranib in patients with Prader-Willi syndrome (PWS) and its ZAF-203 Phase IIb clinical trial of beloranib in patients with severe obesity complicated by type 2 diabetes. Zafgen believes that a sufficient number of patients have completed randomised treatment in both clinical trials to assess the efficacy of beloranib and help inform next steps for the beloranib programme. Following the partial clinical hold recently announced, the company believes it can best preserve the integrity of the data in each clinical trial by closing the randomised portion of the clinical trials early.

Based on consultation with the FDA, Zafgen expects ZAF-311 to remain a pivotal clinical trial. The company expects to report top-line results from both the ZAF-311 and ZAF-203 clinical trials in the first quarter of 2016. Zafgen will continue the six-month open label extension (OLE) of the ZAF-311 clinical trial in PWS to obtain important ongoing efficacy and safety data. As previously planned, the company is continuing to offer an open-ended, unblinded extension study after patients have completed six months of OLE. In consultation with the FDA, a full assessment of the safety and efficacy data from ZAF-311 will be performed to inform the design of ZAF-312, the company’s second PWS Phase III clinical trial. The FDA will review the ZAF-311 clinical trial results on the basis of an abbreviated data package.