Zafgen, Inc. announced strong clinical progress with its lead ZGN-1061 program currently in development for patients with complex type 2 diabetes. Additionally, the company unveiled plans to return to the rare metabolic disease space in 2018, with a second highly optimized MetAP2 development candidate, ZGN-1258, targeting an initial indication in Prader-Willi syndrome (PWS). Enrollment is complete in Zafgen’s Phase 2 clinical trial of ZGN-1061, its investigational MetAP2 inhibitor for the treatment of type 2 diabetes, with 137 patients participating versus 120 planned (+14%) due to accelerated participation interest in the final weeks of the enrollment period. The Phase 2 trial is designed to evaluate safety, tolerability and glucose-lowering efficacy in diabetes patients who are also obese. Topline data are expected mid-year 2018. Zafgen has selected ZGN-1258 as its development candidate for treating rare or orphan metabolic diseases, beginning with PWS, following extensive optimization and preclinical safety and efficacy profiling. Zafgen is beginning investigational new drug (IND) application-enabling work in the first quarter of 2018 in preparation for filing an IND with the U.S. Food and Drug Administration (FDA) and beginning Phase 1 clinical development by the end of the year. ZGN-1258 is designed to change the way the body metabolizes fat, reduce fat mass and decrease hyperphagia in PWS, a rare genetic form of life-threatening obesity characterized by unrelenting pathologic hunger (hyperphagia) leading to dangerous food-seeking behavior. ZGN-1258 exhibits an expanded ability to act on hunger control centers, in addition to peripheral adipose tissue, differentiating it from ZGN-1061. Based on preclinical studies, the efficacy profile of ZGN-1258 closely aligns with data seen in previous trials with the company’s first MetAP2 inhibitor, but, importantly, the new compound appears to have no activity in endothelial cells in vitro, which is critical to reduce risk of thrombosis and thrombotic events in this patient population.