MON-213 Preliminary Patient Demographics And Baseline Characteristics From A Phase 3 Study (sunrize) Of Ersodetug For Hypoglycemia Due To Congenital Hyperinsulinism: Trial In Progress

Abstract Disclosure: G. Saha: Employee and shareholder of Rezolute Inc. E. O'Boyle: Employee and shareholder of Rezolute Inc. L. Lugos: Employee and shareholder of Rezolute Inc. J.K. Sidhu: Employee and shareholder of Rezolute Inc. D.E. Hood: Employee and shareholder of Rezolute Inc. B.K. Roberts: Employee and shareholder of Rezolute Inc. Background: Congenital hyperinsulinism (cHI) is a rare, primarily pediatric condition characterized by recurrent, persistent hypoketotic hypoglycemia due to dysregulated insulin secretion, placing those with the condition at risk for seizures, lifelong neurologic impairment, and death if not recognized and adequately treated in timely fashion. Even with vigilant glucose monitoring alongside intensive medical/feeding regimens, approximately one third of patients/caregivers report recurrent hypoglycemia events (<70mg/dL) daily to several times per week, and neurologic sequalae are common in spite of burdensome management efforts. Ersodetug is a fully human IgG2 monoclonal antibody that allosterically and reversibly binds the insulin receptor, thereby decreasing excessive insulin action in target tissue. A previous Phase 2 study (RIZE) demonstrated that ersodetug was generally safe and well tolerated and resulted in significant reductions in hypoglycemia events and duration. A pivotal, randomized, controlled Phase 3 study with ersodetug (RZ358-301; sunRIZE) is currently ongoing. Objective: Describe the demographic and baseline characteristics of the enrolled sunRIZE study population to inform understanding of disease burden and the extent of persistent hypoglycemia events and time in eligible patients, which are the primary and key secondary study endpoints, respectively, by which the therapeutic response to ersodetug will be evaluated at study completion. Study Design: sunRIZE is a global Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-arm, efficacy, and safety study of ersodetug in participants with a known clinical and biochemical diagnosis of cHI with inadequate hypoglycemia control on available standard of care (SoC) therapies. Eligible patients are required to have ≥3 hypoglycemic events per week by self-monitored blood glucose and spend ≥8% of time in hypoglycemia by continuous glucometer. The study is intended to enroll approximately 56 participants, including approximately 48 participants (≥3 months to ≤45 years of age) in randomized, double-blind, placebo-controlled arms of either 5 or 10 mg/kg ersodetug or placebo, administered bi-weekly during a loading phase, followed by maintenance administration every four weeks, as add on to SoC. The initial eight infants (≥3 months to <1 year of age) received ersodetug in open-label fashion, before subsequently being eligible to participate in the controlled study arms. The pivotal portion of the study is 24 weeks, followed by a roll-over of patients into open-label extension. Results: The trial is in progress with enrollment nearing completion. Preliminary patient demographics and baseline characteristics from at least 56 enrolled participants from the pooled treatment groups will be available for Congress presentation, using summary (descriptive) statistics. Presentation: Monday, July 14, 2025