Rezolute's ersodetug shows strong interim data in tumour HI trial
Rezolute has reported that seven of the eight participants enrolled in its upLIFT Phase 3 study of ersodetug in tumour hyperinsulinism (HI) have met the primary endpoint criterion, with all seven achieving complete discontinuation of intravenous glucose requirements during the pivotal treatment phase.
The Redwood City-based company shared the update alongside full-year fiscal 2026 financial results, having reported interim data from the eight-participant study in June 2026. The eighth participant withdrew consent prior to completing the treatment phase; the individual, who had Stage 4 metastatic colon cancer and a poor ECOG performance status, elected to transition to hospice care and died one week later due to cancer progression. Rezolute is counting that person as a non-responder for the purposes of the primary endpoint assessment. Topline results from upLIFT, which is enrolling up to 16 participants at hospital sites, are expected before the end of calendar 2026.
Congenital HI under regulatory review
Ersodetug's path in congenital HI remains less certain. The Phase 3 sunRIZE study did not meet its primary endpoint, and the FDA is conducting an independent review of additional data submitted by the company in June 2026. That supplementary package included source datasets, summary results from pre-specified and post-hoc analyses, and continuous glucose monitoring-based glucose outcomes from the pivotal portion of the study.
Rezolute confirmed the open-label extension of sunRIZE is continuing, with a high participation rate and a notable reduction in background standard-of-care therapy use, which the company regards as evidence of improved glycaemic control. The company says it will await FDA feedback and reserves the right to request a formal meeting under a regulatory timeline if required. There is a material risk, flagged in the company's forward-looking statements, that the agency could determine a new randomised controlled trial is the only viable path forward for the congenital HI indication, which would significantly delay and complicate ersodetug's commercial trajectory.
Ersodetug is a fully human monoclonal antibody that binds allosterically to the insulin receptor, reducing over-activation by insulin and related substances including IGF-2. The mechanism operates downstream of pancreatic insulin secretion, which the company argues positions the drug to treat refractory hypoglycaemia across all forms of HI.
Financial position and spending trends
Rezolute ended fiscal year 2026 on 30 June with $107.8 million in cash, equivalents and marketable securities, down from $167.9 million a year earlier. Full-year net loss widened modestly to $77.6 million from $74.4 million in fiscal 2025.
R&D expenses fell to $53.8 million for the full year from $61.5 million, largely reflecting reduced manufacturing costs for ersodetug. General and administrative expenses rose sharply, to $29.2 million from $18.4 million, driven by increased share-based compensation and higher professional fees as the company prepares for a potential ersodetug commercial launch.
Market context
The ultra-rare hyperinsulinism space has historically attracted limited competition given the small patient populations involved, but it has drawn increasing interest from specialist rare-disease developers. Diazoxide, the current standard of care for congenital HI, fails or is poorly tolerated in a meaningful proportion of patients, which underpins the unmet need that ersodetug is designed to address. For tumour HI specifically, where treatment options are even more limited, the upLIFT interim data carry particular significance: if the topline readout confirms the trend, Rezolute would be well positioned to seek accelerated or priority regulatory review given the absence of approved therapies in the indication. Cash runway will be a focus for investors, with the $107.8 million balance needing to sustain commercial readiness activities alongside ongoing clinical work.