Rezolute is a clinical-stage rare disease biotech with no approved products or revenue, focused entirely on developing ersodetug, a monoclonal antibody treatment for hyperinsulinism (HI) — a condition where excess insulin production causes dangerous low blood sugar episodes. Ersodetug works by blocking insulin from binding to its receptor in the liver, fat, and muscle, counteracting excess insulin regardless of its source. This receptor-level mechanism differentiates ersodetug from existing therapies, which attempt to suppress insulin production and often fail. Ersodetug's half-life of over two weeks enables potential monthly dosing, an advantage over current treatments. Rezolute is pursuing two indications: congenital HI, an ultra-rare pediatric genetic disorder with no FDA-approved treatment covering all forms, and tumor HI, where patients produce excess insulin due to tumors. The pivotal Phase 3 sunRIZE study for congenital HI completed enrollment in May 2025, with topline results expected in December 2025. The Phase 3 upLIFT study for tumor HI launched in mid-2025, with topline results expected in the second half of 2026. Ersodetug holds Breakthrough Therapy Designation for both indications. Rezolute licenses the ersodetug molecule from XOMA under an exclusive worldwide license. If approved, Rezolute plans to commercialize through a specialty sales force targeting pediatric endocrinology and oncology centers. The company funds operations entirely through capital raises, spending approximately $61.5M on R&D in FY2025.