On December 11, 2025, Rezolute announced topline results from its Phase 3 sunRIZE study of ersodetug (erso) in congenital hyperinsulinism, which did not meet its primary endpoint of statistically significant reduction in hypoglycemia events compared to placebo, nor the key secondary endpoint of change in average daily percent time in hypoglycemia.12
A 45% reduction in hypoglycemia events was observed at the top dose (10 mg/kg) versus 40% in the placebo arm, but differences were not statistically significant.2
Rezolute shares (NASDAQ:
RZLT) dropped as much as 90% in intraday trading on December 11, 2025, following the announcement.1
The company expressed disappointment and is conducting further evaluation of the results to inform next steps; ersodetug was positioned as their lead asset for hypoglycemia due to hyperinsulinism.12
Hagens Berman launched an investigation into potential misleading statements by Rezolute about ersodetug's efficacy, citing prior assurances in mid-November 2025.1
Sources:
1. https://www.prnewswire.com/news-releases/rezolute-inc-rzlt-shares-tank-90-amid-lead-asset-trial-failure----hagens-berman-investigating-302639771.html
2. https://ir.rezolutebio.com/news/detail/368/rezolute-announces-phase-3-sunrize-study-results-in-congenital-hyperinsulinism