Rezolute, Inc. announced results following administration of RZ358 to a patient with refractory hypoglycemia due to tumor-mediated hyperinsulinism (tmHI) on a compassionate-use basis, under its expanded access program (EAP).  The Company previously reported on the successful use of RZ358 for a patient with refractory hypoglycemia due to metastatic insulinoma, which has since been published in a recent edition of the New England Journal of Medicine (389;8). As a result of that publication, the Company recently received and granted a request from a physician-investigator who had FDA approval to use RZ358 for a patient with refractory hypoglycemia due to a metastatic, insulin-secreting cervical cancer. The patient began receiving treatment with RZ358 in September 2023, which resulted in resolution of her hypoglycemia and enabled her to be discharged from the hospital to resume cancer-directed therapy while continuing to receive RZ358 to control hypoglycemia. Notably, the individual with metastatic insulinoma has remained on RZ358 for nearly a year.

RZ358 is a fully human monoclonal antibody that works downstream from the pancreas and instead binds to a unique allosteric site on insulin receptors in the liver, fat, and muscle. The antibody counteracts the effects of elevated insulin in the body by modulating insulin's binding, signaling, and activity to restore glucose levels to a normal range. Rezolute believes that RZ358 is ideally suited as a potential therapy for congenital hyperinsulinism (cHI) and other conditions characterized by excessive insulin levels.

Because RZ358 acts downstream from the pancreas, it has the potential to be universally effective at treating cHI, regardless of the causative genetic defect, as well as acquired forms of HI such as those mediated by insulinomas and other tumor types. RZ358 received Orphan Drug Designation in the United States and European Union for the treatment of cHI, as well as Pediatric Rare Disease Designation in the US. The Company?s Phase 2b trial (RIZE) of RZ358 in patients with cHI, demonstrated that RZ358 was generally safe and well-tolerated, as well as highly effective in correcting hypoglycemia, in participants who were failing available standard of care therapies.

The Company is on track to initiate a pivotal Phase 3 trial of RZ358 (sunRIZE) outside the US in individuals three months of age and older in Fourth Quarter 2023. The addressable market for cHI is estimated to be approximately 3,500 patients in the US and 10,000 patients overall in addressable markets.