Rezolute Completes Enrollment for Phase 3 sunRIZE Study of Ersodetug in Congenital Hyperinsulinism

Rezolute, Inc., headquartered in Redwood City, California, has reached a critical milestone in its quest to provide a new treatment for congenital hyperinsulinism (HI) by completing participant enrollment for its Phase 3 sunRIZE study. The study aims to evaluate the efficacy and safety of the drug ersodetug, with enrollment surpassing expectations by including 62 participants, approximately 15 percent of whom are from U.S. sites. The company anticipates releasing the topline results by December 2025.

The sunRIZE study is a global, multicenter, double-blind, randomized, placebo-controlled trial. It is designed to assess the effectiveness and safety of ersodetug in patients aged between 3 months and 45 years who suffer from persistent hypoglycemia despite receiving the currently available standard of care. Participants are divided into three groups to receive either 5 or 10 mg/kg of ersodetug or a placebo, in addition to their existing treatment regimen. The drug is administered bi-weekly during a loading phase, transitioning to a monthly schedule over the six-month controlled treatment period. Following this phase, there is an option for participants to enter an open-label extension to continue receiving ersodetug, with the extension showing a strong continuation rate.

The study, initially aimed at enrolling 56 participants from various countries, has exceeded its target. The principal efficacy outcomes are the changes from baseline in the average weekly hypoglycemia events and the average time spent in hypoglycemia over the study period. The demographic and baseline characteristics of the sunRIZE participants are generally consistent with those in the earlier Phase 2 RIZE study, which successfully evaluated similar endpoints in this patient group.

Ersodetug, the focus of this study, is a fully human IgG2 monoclonal antibody. It functions by binding allosterically to the insulin receptor, reducing its over-activation by insulin and related substances like IGF-2, which is crucial in managing hyperinsulinism. By acting downstream from the pancreas, ersodetug offers potential benefits across various forms of congenital and acquired HI, aiming to mitigate hypoglycemia effectively.

Rezolute, Inc. is committed to advancing treatments for rare diseases, particularly those related to hypoglycemia induced by hyperinsulinism. The company’s lead candidate, ersodetug, has demonstrated significant benefits in both clinical trials and practical applications for treating congenital and tumor-related HI. Assuming favorable data from the sunRIZE study, Rezolute plans to submit a Biologics License Application to the U.S. Food and Drug Administration in 2026 for ersodetug’s approval.

This achievement in the sunRIZE study represents a pivotal step forward for Rezolute and individuals impacted by congenital hyperinsulinism. Brian Roberts, M.D., Chief Medical Officer at Rezolute, expressed gratitude towards the patients, families, and investigators participating in the study. He emphasized the importance of this milestone in potentially offering a new therapeutic solution in a field where options have been limited. Rezolute remains dedicated to improving care in this underserved area and eagerly anticipates sharing the study’s results later this year.