Rezolute has made its pitch to challenge Zealand Pharma for the congenital hyperinsulinism (CHI) space. The biotech linked its candidate to a 75% reduction in severe low blood sugar events in children, emboldening it to raise $130 million to support a push into phase 3.
CHI, a rare disease driven by abnormally high levels of insulin, causes frequent episodes of low blood sugar that are associated with symptoms such as lethargy and irritability in the near term and severe complications including seizures and intellectual disability as repeated hypoglycemic episodes occur. To improve outcomes, Rezolute took the negative allosteric modulator of insulin RZ358 into clinical trials.
Rezolute now has early evidence that its antibody may work. The phase 2b enrolled 23 children with an average age of 6.5 years. Investigators put the participants in one of four dose cohorts and gave them a 30-minute intravenous infusion every other week for an eight-week treatment period.
The number of severe hypoglycemic events across all four cohorts fell 71%. Limiting the analysis to the anticipated therapeutic doses improved the size of the change to 75%. The arms excluded from that analysis—the low dose and titrated cohort—found no effect on severe hypoglycemic events but falls were seen at the 6-mg/kg and 9-mg/kg doses.
Those two arms performed best against other measures of efficacy and underpinned significant findings in the pooled analyses. Across all four cohorts, the time in hypoglycemia, as measured by continuous glucose monitors, fell by 56% over the course of the study. The time in severe hypoglycemia fell by 63%.
On the safety front, Rezolute said “there were no adverse drug reactions, study discontinuations or occurrences of clinically significant hyperglycemia,” adding that “the observed blood levels of RZ358 were well below levels that were safely tested in long term toxicology studies in non-human primates.”
The results come from a small, open-label clinical trial, but Rezolute was sufficiently encouraged to look forward to phase 3. Investors have bought into Rezolute’s plans, participating in a $130 million offering that tees the biotech up to advance into a registrational trial that will show whether RZ358 is a genuine challenger for the CHI market.
Zealand posted the first phase 3 data on dasiglucagon in CHI late in 2020, revealing that adding the drug to standard of care failed to improve the rate of low blood sugar. However, Zealand took heart from an exploratory analysis and continued development, putting it on track to deliver phase 3 data in neonates aged up to 12 months this quarter. Zealand already sells dasiglucagon, branded Zegalogue, as a diabetic rescue medication.
A small band of other companies are going after the same opportunity. Eiger BioPharmaceuticals is at a similar point to Rezolute, having taken its GLP-1 antagonist avexitide to the cusp of phase 3, and Xinvento recently emerged as a new challenger that is affiliated with biotech executives including Ed Kaye, John Maraganore, David Meeker.