ersodetug (RZ358) - (sunRIZE)

Sept. 9, 2026: Rezolute, Inc. (NASDAQ: RZLT) said FDA is still reviewing additional analyses from the Phase 3 sunRIZE study of ersodetug in congenital hyperinsulinism (HI), with no set timeline for feedback on a potential regulatory path forward. SunRIZE previously missed its primary and key secondary endpoints; in December 2025, the company said reductions in hypoglycemia versus placebo were not statistically significant. After a March 2026 Type B meeting, FDA requested more data, and in June 2026 Rezolute submitted source and analysis datasets plus pre-specified, post-hoc, and sensitivity analyses focused on CGM-based outcomes. The company said these showed consistent glycemic improvements versus placebo at both dose levels, including 50%+ reductions in average daily percent time in hypoglycemia and average weekly hypoglycemia events.

The sunRIZE open-label extension is ongoing, with high retention and cumulative treatment duration of roughly nine months to over two years; Rezolute said ongoing monitoring and reduced use of background standard-of-care therapies may indicate longer-term benefit.

Separately, enrollment continues in the Phase 3 upLIFT study of ersodetug in tumor HI, with topline results still expected before the end of 2026.