Rezolute disclosed that its Phase 3 trial of ersodetug in congenital hyperinsulinism failed to meet the primary efficacy endpoint, triggering a catastrophic market reaction and an immediate share‑price collapse. The highest‑dose cohort showed non‑significant improvements versus placebo and two patients experienced serious hypersensitivity reactions that prompted discontinuation. Management said it will consult the FDA to define next steps while conducting an in‑depth analysis of the data. The failure places the company’s commercialization plans and near‑term valuation under severe stress.