A Phase 3 interventional study of RZ358 (5 mg/kg) + SOC (Standard-of-Care) or Placebo + SOC and RZ358 (10 mg/kg) or Placebo + SOC in Congenital Hyperinsulinism, sponsored by Rezolute. Active, not recruiting at 18 sites in 13 countries. Open to participants aged 3 Months to 45 Years. Per ClinicalTrials.gov, last updated 2026-01-08.
Sponsored by Rezolute · Phase 3, Interventional, and Treatment
The Phase 3 pivotal study is designed to evaluate the efficacy and safety of RZ358 for the treatment of congenital hyperinsulinism (HI) as add-on to standard-of-care (SOC) therapy compared to SOC alone over 24 weeks and to evaluate the longer-term safety and efficacy of RZ358 during a subsequent open-label extension (OLE) period.
Congenital hyperinsulinism (HI) is the most common cause of recurrent hypoglycemia in neonates and infants with an incidence of approximately 1 in 25,000 to 1 in 50,000 live births in the general population, and as high as 1 in 2,500 in certain populations with substantial consanguinity. Despite improved recognition, there is no satisfactory treatment or cure for congenital HI. Current medical therapies for congenital HI are directed at reducing or eliminating insulin production and/or secretion from the beta-cell. These current medications, however, achieve suboptimal glycemic control and/or have undesirable side effects. A therapy which safely and effectively attenuates the activity of insulin would address an important unmet need for these and other conditions associated with HI. This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled (SOC alone), parallel-arm, efficacy, and safety study of RZ358 in participants with congenital HI who have not achieved adequate hypoglycemia control with reasonable attempts at using usual SOC medical therapy. The study will randomize approximately 48 participants (≥1 year to ≤45 years of age) in a 1:1 ratio into 2 dosing arms (5 or 10 mg/kg with) and further randomize participants within each dosing level in a 2:1 ratio to receive RZ358 as add-on to SOC or placebo as add-on to SOC. An additional open-label (OL) arm will be conducted in parallel for participants who are ≥3 months to \<1 year old (n=8), Upon completion of the pivotal treatment period (24-weeks), participants may roll-over to the OLE period at the discretion of the investigator and Sponsor.
38 studies on the registry are indexed under Congenital Hyperinsulinism; 6 are open to participants now.
This study's planned enrollment of 56 is above the median of 17 across 30 interventional studies indexed under Congenital Hyperinsulinism.
Browse Congenital Hyperinsulinism studies →Rezolute is the lead sponsor of 5 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
At screening, aged ≥ 3 months and ≤ 45 years old.
An established clinical diagnosis of congenital HI (hyperinsulinism), with or without identification of a known monogenic variant by genetic testing.
Participant has failed to achieve adequate glycemic control with appropriate and reasonable trials of locally accepted and available Standard of Care (SOC) medical therapies (e.g., diazoxide and somatostatin analogs (SSAs)) per the judgment of the investigator.
Experiencing ≥ 3 hypoglycemia events per week by screening Self-Monitoring Blood Glucose (SMBG) and average daily percent time with hypoglycemia of ≥ 8% of the monitored screening Continuous Glucose Monitor (CGM) time.
Exclusion Criteria:
(ALT), aspartate aminotransaminase (AST), total (TB), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) ≥ 1.5 × the for the age-specific reference range, regardless of assessed significance.
(BMI) ≥ 35 kg/m2 for participants aged 18 years and above, or BMI ≥ 99% (percentile) per Centers for Disease Control and Prevention growth charts for participants > 12 and \< 18 years of age (no BMI exclusion for participants ≤ 12 years of age).
A known clinical diagnosis of diabetes or pre-diabetes, or a history of insulin dependency within 3 months of screening.
Average daily percent time with hyperglycemia ≥ 5% of the monitored screening continuous glucose monitoring (CGM) time.
Known allergy or sensitivity to RZ358 or any component of the drug.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants ≥1 year old who receive SOC therapy and 5 mg/kg of RZ358 or placebo
Drug: RZ358 (5 mg/kg) + SOC (Standard-of-Care) or Placebo + SOC
Participants ≥1 year old who receive SOC therapy and 10 mg/kg of RZ358 or placebo
Drug: RZ358 (10 mg/kg) or Placebo + SOC
Infant participants from ≥3 months to \<1 year old who receive SOC therapy + RZ358 starting at 5 mg/kg and increasing to 10 mg/kg of RZ358, as needed, per the protocol schedule
Drug: RZ358 (5-10 mg/kg) + SOC
Participants ≥1 year old who receive SOC therapy and 5 mg/kg of RZ358 or placebo
Participants ≥1 year old who receive SOC therapy and 10 mg/kg of RZ358 or placebo
Drug page: Ersodetug
Infant participants from ≥3 months to \<1 year old who receive SOC therapy + RZ358 starting at 5 mg/kg and increasing to 10 mg/kg of RZ358, as needed, per the protocol schedule
Glycemic efficacy: Target glucose control
Change in average weekly hypoglycemia events from baseline by point-of-care Self-Monitoring Blood Glucose (SMBG)
Time frame: 24 weeks
Glycemic efficacy: Occurrence of hypoglycemia
Change in average daily percent time in hypoglycemia from baseline by Continuous Glucose Monitor (CGM)
Time frame: 24 weeks
Safety Assessments: safety and tolerability of RZ358 in patients with congenital hyperinsulinism
Treatment emergent Adverse Events (AEs) and Serious Adverse Events (SAEs) captured per Common Terminology Criteria for Adverse Events (CTCAE) guidelines and coadded per Medical Dictionary for Regulatory Activities (MedDRA) will be summarized by system organ class, preferred term, and analyzed by number and percentage of events by treatment groups. Hepatic ultrasound: evaluated for significant structural changes (e.g. peliosis Hepatitis) Immunogenicity assessments: Blood samples for anti-drug antibody to RZ358 will be evaluated based on the titer, and potential neutralization effects. Hyperglycemia events: Will be evaluated by SMBG at thresholds of \>250 mg/dL and \>300 mg/dL and summarized by the treatment groups.
Time frame: 24 weeks, plus up to two years of Open-Label Extension (OLE) period
Safety Assessments: safety and tolerability of RZ358 in patients with congenital hyperinsulinism, Laboratory tests evaluated for significant changes from baseline by treated groups
Laboratory parameters: ALT (U/L), AST (U/L), and ALP (U/L) will be evaluated for any significant changes from baseline (\>3x ULN) by treatment groups. Vital Signs: blood pressure (mm of Hg), heart rate (beats/minute), and respiration (rate/minute) will be evaluated for any significant changes from baseline by treatment groups. ECG: heart rate (beats/minute), PR (milliseconds), QTcF intervals (milliseconds) will be evaluated for any significant changes from baseline by treatment groups.
Time frame: Time Frame: 24 weeks, plus up to two years of Open-Label Extension (OLE) period
Other Glycemic efficacy: Self-Monitoring Blood Glucose (SMBG)
Proportion of participants experiencing no potentially serious hypoglycemia events by SMBG.
Time frame: 24 weeks
Other Glycemic efficacy: Self-Monitoring Blood Glucose (SMBG) Weekly Assessment
Change in average weekly incidence of potentially serious hypoglycemia events by Self-Monitoring Blood Glucose (SMBG).
Time frame: 24 weeks
Other Glycemic efficacy: Continuous Glucose Monitor (CGM) Daily Assessment
Change in average daily percent time with potentially serious hypoglycemia by Continuous Glucose Monitor (CGM).
Time frame: 24 weeks
Other Glycemic efficacy: Continuous Glucose Monitor (CGM) Overnight Assessment
Change in average 8-hour overnight percent time with hypoglycemia by CGM. Change in average daily duration (min) with hypoglycemia by CGM. Proportion of participants achieving \<4% average daily time in by CGM
Time frame: 24 weeks
Plan to share: No
No publications or documents are linked to this record.
Ran from Jan 2024 to primary completion in Nov 2025, 22 months.
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This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Ersodetug
Rezolute