Rhythm Pharmaceuticals, Inc. announced recent progress in the clinical development of the company’s lead product candidate, setmelanotide, a first-in-class melanocortin-4 receptor (MC4R) agonist. Following recent discussions with the U.S. Food & Drug Administration (FDA), Rhythm has finalized the protocol for its ongoing, open-label, single-arm, multinational pivotal Phase 3 clinical trial evaluating setmelanotide in patients with POMC deficiency obesity, an ultra-rare orphan disease that results in hyperphagia and severe, early-onset obesity. The FDA previously granted Breakthrough Therapy Designation for setmelanotide in this indication. The study originally positioned mean percentage change in weight from baseline as the primary endpoint, and a categorical analysis of responders for weight, defined as patients achieving a 10% change from baseline, as the first secondary endpoint. Following recent discussions with regulatory authorities, the study’s primary endpoint will now be the responder analysis, with mean percentage change in weight as the first secondary endpoint, in a change that increases the power of the trial. Other key secondary endpoints on hunger remain unchanged. The company confirms plans to file a New Drug Application (NDA) with the FDA based on one-year data from a cohort of 10 patients. The company currently has eight patients enrolled in its pivotal Phase 3 clinical trial, and expects to complete enrollment of the 10 required patients in the first half of 2018. In addition, the company plans to continue enrolling supplemental patients who may not complete one year of treatment at the time of NDA filing, including patients between six and 11 years of age under the implementation of a pediatric amendment, to provide additional important data regarding the use of setmelanotide in people living with POMC deficiency obesity. The company continues to expect to report initial data from this trial in the first half of 2019.