Rezolute says FDA recommends pre‑BLA meeting after congenital HI trial miss
Agency feedback follows a Phase 3 miss in congenital hyperinsulinism; Rezolute will weigh its filing strategy after tumor HI data.
Adrian Kessler
A request for a pre-BLA meeting is the next regulatory step for Rezolute, Inc. NASDAQRZLT after it said on Oct. 5 that the FDA recommended one before a possible ersodetug filing for congenital hyperinsulinism. The advice followed an FDA review of data from a 63-person Phase 3 trial that missed its primary and key secondary endpoints.
Rezolute has not submitted a biologics license application and gave no date for the proposed meeting in its release. The company said the FDA offered no opinion on whether the antibody could be approved; that question would be addressed during a formal application review. Rezolute warned that the agency could still require another randomized trial.
Rezolute is a drug developer based in Redwood City, California, studying an antibody for recurring low blood sugar caused by hyperinsulinism. The antibody remains investigational while the company tests it in congenital and tumor-related disease.
Shares of Rezolute NASDAQRZLT closed 7.98 per cent higher at US$4.33 on Nasdaq at 4 p.m. EDT on Oct. 5. Rezolute expects the tumor HI study's topline results in the fourth quarter of 2026 and plans to assess its filing strategy after that readout.
Missed Endpoints Set the Filing Burden
The Dec. 11, 2025, sunRIZE readout said the highest ersodetug dose reduced weekly hypoglycemia events measured by finger-stick testing about 45 per cent from baseline, against about 40 per cent on placebo. That difference was not statistically significant, and the company gave no numerical p value or confidence interval in the release.
For the key secondary measure, time in hypoglycemia measured by continuous glucose monitoring fell about 25 per cent on the higher dose while it rose about five per cent on placebo. That comparison also missed statistical significance in the prespecified assessment window.
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The trial enrolled 63 people in three arms: two ersodetug doses, 5 and 10 milligrams per kilogram, and placebo on top of standard care. Treatment lasted 24 weeks. Rezolute reported two serious hypersensitivity reactions leading to early drug discontinuation; excess hair growth was the most commonly reported adverse event among treated participants compared with placebo.
According to Rezolute, the FDA acknowledged at a March 2026 meeting that behaviour can complicate finger-stick measurements in this population and requested continuous-monitoring data. Rezolute submitted datasets and additional analyses in June; its Oct. 5 account says the agency then encouraged a Type B pre-BLA request despite the missed endpoints.
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"We appreciate FDA's thorough review of the extensive body of data generated in sunRIZE and are encouraged by the Agency's recognition that this data will require in-depth evaluation during a formal BLA review," Rezolute chief executive Nevan Charles Elam said in the Oct. 5 release.
Rezolute's Sept. 24 results reported US$107.8 million in cash, cash equivalents and investments in marketable securities as of June 30, 2026. That compares with US$167.9 million at June 30, 2025.
Rescue Products Serve Different Patients
The wider hypoglycemia market includes Xeris Biopharma Holdings, Inc. NASDAQXERS, whose Gvoke HypoPen treats severe low blood sugar in people with diabetes. Amphastar Pharmaceuticals, Inc. NASDAQAMPH markets Baqsimi nasal glucagon for the same acute diabetes setting. Those product pages describe emergency treatment, while Rezolute is testing ersodetug for recurring hypoglycemia in hyperinsulinism.
As a dated sector reference, the iShares Biotechnology ETF NASDAQIBB closed down 0.33 per cent at US$205.29 on Nasdaq at 4 p.m. EDT on Oct. 2. That quote predates Rezolute's Oct. 5 announcement.
Rezolute expects upLIFT topline results in the fourth quarter of 2026. Its Oct. 5 release says that readout will inform its strategy for possible biologics applications in congenital and tumor HI, while the congenital HI pre-BLA meeting remains undated.
