Zafgen, a Boston-based biopharmaceutical company dedicated to improving the health and well-being of patients affected by obesity and complex metabolic disorders, has announced a clinical update for beloranib, the company’s lead MetAP2 inhibitor product candidate.

After review of its ongoing clinical trials, the company has elected to proceed with efficacy and safety data analysis and close the randomized 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 randomized treatment in both clinical trials to assess the efficacy of beloranib and help inform next steps for the beloranib program.

Following the partial clinical hold announced last week, the company believes it can best preserve the integrity of the data in each clinical trial by closing the randomized portion of the clinical trials early. Zafgen, based on consultation with the FDA, 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 has informed the company that it will review the ZAF-311 clinical trial results on the basis of an abbreviated data package.

“The strategic decision to analyze results from the ZAF-311 and ZAF-203 clinical trials early allows us to better preserve data integrity by limiting dose interruption in both clinical trials, and inform the future development of this important product candidate,” said Dennis Kim, M.D., chief medical officer of Zafgen. “PWS is a life-threatening and complex rare disorder that severely impacts the quality of life of both patients and their families, and we continue to believe that beloranib may have an important role in addressing hyperphagia and underlying obesity associated with this disorder. We will continue to treat, closely monitor and follow patients in the ZAF-311 extension portion of the clinical trial.”

As previously reported, 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 that event was related to treatment with beloranib.