Rezolute, Inc. (NASDAQ:RZLT), a clinical-stage biotechnology company developing treatments for rare metabolic diseases, announced that its ongoing Phase 3 upLIFT study of ersodetug in patients with tumor hyperinsulinism has met its primary efficacy endpoint, based on preliminary data evaluated on November 5, 2026.
The open-label study is assessing ersodetug in patients experiencing uncontrolled hypoglycemia associated with insulin-secreting or non-islet cell tumors.
The primary endpoint measures the proportion of participants achieving at least a 50% reduction in glucose infusion rate (GIR), an indicator of their dependence on intravenous glucose to manage low blood sugar.
Phase 3 Study Results
Of the 16 participants enrolled in the study, 13 have met the primary responder criterion, including 12 who were able to discontinue intravenous glucose completely.
The study’s statistical success threshold requires at least nine responders among the 16 enrolled participants, equivalent to approximately 56%, to ensure that the lower bound of the 95% confidence interval exceeds 30%.
Three participants remain in the pivotal treatment period, including two who have not yet met the responder criterion.
One participant previously discontinued treatment to enter home hospice care and subsequently died from cancer progression. The participant has been classified as a non-responder in the primary endpoint analysis.
Rezolute expects to report the completed study results, including the formal statistical analysis, by mid-December 2026.
Safety and Patient Population
The study enrolled 12 patients with insulin-secreting malignant islet cell tumors, known as insulinomas, and four patients with non-islet cell tumors.
According to Rezolute, ersodetug has been well tolerated during both the pivotal treatment and extension phases, with no drug-related safety findings identified to date.
The upLIFT study administers ersodetug at 9 mg/kg weekly for eight weeks alongside standard treatment. Participants may subsequently enter a long-term extension phase with less frequent dosing.
Additional study measures include complete discontinuation of intravenous glucose, time to hospital discharge, frequency and duration of hypoglycemic episodes, and patient-reported quality of life.
Regulatory Development Plans
Rezolute said it intends to discuss the development of ersodetug with the US Food and Drug Administration during the first quarter of 2027.
The company is pursuing potential regulatory approval pathways for the treatment of both tumor hyperinsulinism and congenital hyperinsulinism.
“We believe that we are well positioned to advance both congenital HI and tumor HI into the approval process next year and we look forward to discussions with FDA in the first quarter of 2027,” said Nevan Charles Elam, founder and chief executive officer of Rezolute.
About Ersodetug
Ersodetug is an investigational monoclonal antibody designed to reduce excessive activation of the insulin receptor by insulin and related substances, including insulin-like growth factor 2 (IGF-2).
The treatment is being developed to address refractory hypoglycemia associated with different forms of hyperinsulinism, including congenital and tumor-related conditions.
Tumor hyperinsulinism can arise from insulin-producing tumors or other malignancies that release substances capable of activating insulin receptors, resulting in recurrent episodes of low blood glucose.
Ersodetug has not received regulatory approval, and its safety and efficacy remain under clinical evaluation.