Rezolute, Inc.

Summary of Key Additional Data Presented

Figure 1: Consistent and Clinically Relevant Glycemic Improvements in Ersodetug Treatment Groups Compared to Placebo Across Time & Multiple CGM Outcomes (LS-Mean [95% CI] Percent Change from Baseline; FAS Population)

The Company is also assessing the longer-term efficacy and safety of ersodetug in a real-world setting in an ongoing OLE phase of the study, including the roll-over of placebo participants. Following the conclusion of the randomized and placebo-controlled phase of sunRIZE, all 59 study completers elected to enter the OLE, as previously reported by the Company. Reflecting no change since last reported, 57 participants continue to attend regular study visits at sunRIZE study centers to receive ersodetug in the OLE, now representing a cumulative ersodetug exposure duration in the study ranging from approximately 6 to 24 months. Preliminary OLE observations demonstrate continued glycemic benefit, including a clinically significant change in glycemic control in the rolled-over placebo participants compared to the controlled period of the study. These glycemic benefits have enabled a concurrent significant overall reduction in background SOC therapies (e.g. diazoxide, somatostatin analogs, and/or regular tube feeds), with a significant number of patients now receiving ersodetug as monotherapy.

Notably, a summary of these same CGM-based study outcomes and preliminary observations from the OLE phase of the study were recently discussed with the U.S. Food and Drug Administration (FDA) as part of the Company’s Type B meeting held on March 17, 2026. The meeting resulted in the agency acknowledging challenges associated with the study primary endpoint (events by finger-stick self-monitored blood glucose [SMBG]), and concluded with the agency requesting that the Company submit the broader study data for the agency’s comprehensive evaluation to inform next steps for the program.

“We are pleased to highlight that deeper analyses of the sunRIZE outcomes and ongoing observations from the extension phase of the study consistently indicate evidence of target engagement, drug activity, and the potential for meaningful therapeutic benefit from ersodetug,” said Brian Roberts, M.D., Chief Medical Officer of Rezolute. “These results underscore our confidence in the potential of ersodetug to transform the HI treatment landscape and embolden our mission to achieve alignment with FDA on an acceptable path to approval in this indication, so that we can keep delivering ersodetug to patients and families living with congenital HI.”

The Company’s full data presentation from PES can be found on the Publications and Presentations page of the Rezolute website here.