Phase 1/2a: RN3161 alone and with tirzepatide for safety, how the drug works in the body, and effects on weight in adults with overweight or obesity
A Randomized, Double-Blind, Placebo-Controlled Phase 1/2a Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and Effect on Body Weight of RN3161 as Monotherapy and in Combination With Tirzepatide in Adults With Overweight and Obesity
This trial will test RN3161 by itself in healthy volunteers and RN3161 with tirzepatide in adults with overweight or obesity to see if it is safe and changes body weight.
Quick facts
| Phase | Phase1; Phase2 |
|---|---|
| Study type | Interventional |
| Enrollment | 104 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | Ikaria Bioscience Pty Ltd Industry-sponsored |
| Locations | 1 site (Melbourne, Victoria) |
| Trial ID | NCT07245771 on ClinicalTrials.gov |
What this trial studies
This phase 1/2a trial tests RN3161 as a single agent and in combination with tirzepatide to characterize safety, tolerability, pharmacokinetics, pharmacodynamics, and effects on body weight. RN3161 will be given alone to healthy volunteers and given with tirzepatide to adults meeting prespecified BMI ranges (with Asian ancestry thresholds applied where specified), and placebo control arms are included. Participants will undergo clinical monitoring and serial blood sampling to measure drug levels, biological activity, adverse events, and changes in body weight over the dosing period. Early phase portions emphasize safety and PK/PD, while the phase 2a portion looks for preliminary signals of weight change and combination tolerability.
Who should consider this trial
Good fit: Adults with overweight or obesity who meet the trial BMI ranges (including lower thresholds for participants of Asian ancestry) and stable weight are eligible, and a separate cohort of healthy volunteers will be enrolled for RN3161 monotherapy.
Not a fit: People with diabetes (excluded here), uncontrolled cardiovascular or other serious medical conditions, or those unable to attend the Melbourne site are unlikely to be eligible or to benefit from participation.
Why it matters
Potential benefit: If successful, the combination could offer greater or complementary weight loss benefits compared with current options and expand treatment choices for people with overweight or obesity.
How similar studies have performed: Tirzepatide has produced substantial weight loss in other clinical programs, but RN3161 is a novel agent and combining it with tirzepatide is exploratory with limited prior human data.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * BMI: Obesity: BMI ≥ 30 kg/m² for participants with no Asian ancestry and ≥ 27.5 kg/m² for participants with Asian ancestry that has been stable (± 5%) for the previous 3 months (based on participant self-report or available medical records), with or without a weight-related comorbidity (excluding diabetes) Overweight: BMI 27 to \<30 kg/m² for participants with no Asian ancestry and 23.0 to \<27.5 kg/m² for participants with Asian ancestry that has been stable (± 5%) for the previous 3 months (based on participant self-report or available medical records), with at least 1 weight-related comorbidity (excluding diabetes) Weight-related comorbidities include a diagnosis of the following: * Hypertension: seated BP ≤ 140/90 mm Hg; receiving ≤ 2 stable (≥ 4 weeks) agents limited to ACE inhibitors, angiotensin receptor blockers, calcium channel blockers, or thiazide ≤ 25 mg, or untreated * Dyslipidemia: stable use of lipid-lowering agents for dyslipidemia (LDL-C \< 150 mg/dL, triglycerides \< 300 mg/dL) * Osteoarthritis Exclusion Criteria: * self-reported or documented weight gain or loss \>5% within 3 months prior to screening * use of GLP1R agonists within 6 months of screening * intolerance to GLP-1 medications in the past * use of non-GLP1R medications for weight loss within 3 months of screening * HbA1c \>6.5% * diagnosis of significant liver disease * history of malignancy or anaphylaxis * use of any siRNA agent in the prior 12 months
Where this trial is running
Melbourne, Victoria
- Nucleus Network Pty Ltd — Melbourne, Victoria, Australia (Recruiting)
Study contacts
- Principal investigator: Philip Ryan, MD — Nucleus Network Pty Ltd.
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.