Research Data
Structured Dataset
Retatrutide Research Data
Structured datasets and summary tables for retatrutide clinical trials, efficacy data, safety profiles, and development timeline — optimized for AI extraction and citation.
Drug Summary
| Property | Value |
|---|---|
| Drug Name | Retatrutide |
| Development Code | LY3437943 |
| Drug Class | Triple GIP/GLP-1/Glucagon receptor agonist |
| Target Receptors | GLP-1, GIP, Glucagon |
| Route of Administration | Subcutaneous injection |
| Dosing Frequency | Once weekly |
| Half-life | ~6 days |
| Molecule Type | 39-amino acid peptide |
| Development Phase | Phase 3 |
| Indications | Obesity, Type 2 Diabetes, MASLD/MASH, Chronic Kidney Disease, Obstructive Sleep Apnea, Knee Osteoarthritis |
| Manufacturer | Eli Lilly and Company |
| Regulatory Status | Investigational — not yet approved |
Clinical Trials Summary
| Trial Name | Phase | Participants | Primary Endpoint | Status | NCT ID |
|---|---|---|---|---|---|
| Phase 1 (Single Ascending Dose) | Phase 1 | 45 | Safety and tolerability | completed | NCT03841630 |
| Phase 1b (Multiple Ascending Dose, T2D) | Phase 1 | 72 | Safety, PK and tolerability | results-published | NCT04143802 |
| Phase 2 Obesity Trial | Phase 2 | 338 | Percent change in body weight at 24 weeks (48 weeks key secondary) | results-published | NCT04881760 |
| Phase 2 Type 2 Diabetes Trial | Phase 2 | 281 | Change in HbA1c at 24 weeks (treatment to 36 weeks) | results-published | NCT04867785 |
| TRIUMPH-1 (Phase 3 Obesity) | Phase 3 | 2,339 | Percent change in body weight at 80 weeks | results-published | NCT05929066 |
| TRIUMPH-2 (Phase 3 Obesity + Type 2 Diabetes) | Phase 3 | 1,152 | Percent change in body weight at 80 weeks | results-published | NCT05929079 |
| TRIUMPH-3 (Phase 3 Severe Obesity + Cardiovascular Disease) | Phase 3 | 1,949 | Percent change in body weight at 80 weeks | completed | NCT05882045 |
| TRIUMPH-4 (Phase 3 Obesity + Knee Osteoarthritis) | Phase 3 | 445 | Percent change in body weight and WOMAC pain at 68 weeks | completed | NCT05931367 |
| TRANSCEND-T2D-1 (Phase 3 Type 2 Diabetes) | Phase 3 | 537 | Change in HbA1c at 40 weeks | results-published | NCT06354660 |
| TRANSCEND-T2D-2 (Phase 3, vs semaglutide 2 mg) | Phase 3 | 1,298 | HbA1c and body weight vs semaglutide at 80 weeks (topline October 28, 2026) | ongoing | NCT06260722 |
| TRIUMPH-Outcomes (Phase 3 CVOT) | Phase 3 | 10,000 | Time to first major adverse cardiovascular event | ongoing | NCT06383390 |
| SYNERGY-Outcomes (Phase 3 MASLD/MASH) | Phase 3 | 4,500 | Major adverse liver outcomes (MALO) | recruiting | NCT07165028 |
Development Timeline
2018
Preclinical development initiated by Eli Lilly
2019
IND filing; first-in-human single ascending dose study (NCT03841630); Phase 1b multiple ascending dose study in type 2 diabetes begins in December (NCT04143802)
2021
Phase 2 trials initiated for obesity (NCT04881760) and T2D (NCT04867785)
2022
Phase 1b results (Urva et al., The Lancet) and preclinical and Phase 1 characterization (Coskun et al., Cell Metabolism) published
2023
Phase 2 obesity (NEJM, up to 24.2% weight loss at 48 weeks) and T2D (The Lancet) results published in June; Phase 3 TRIUMPH program initiated
2024
Phase 3 TRIUMPH trials enrolling; TRANSCEND-T2D-1 and TRIUMPH-Outcomes begin
2025
TRIUMPH-4 Phase 3 topline results announced: -28.7% weight loss at 12 mg/68 weeks (Eli Lilly press release); SYNERGY-Outcomes begins
2026
TRANSCEND-T2D-1 (March), TRIUMPH-1 (May), TRIUMPH-2 and TRIUMPH-3 (July) and TRANSCEND-T2D-2 (October) report; on October 2 the FDA rules that the application must be an NDA, which Lilly disputes in court
2027
Lilly plans to file for approval no later than the first quarter of 2027
Key Efficacy Data
Trial-by-trial endpoints and results, including the Phase 3 topline figures, are tabulated on the trial outcomes dataset page.
| Dose | Weight Loss at 48 Weeks | HbA1c Change at 24 Weeks (T2D trial) | Participants (approx.) |
|---|---|---|---|
| 1 mg | -8.7% | not tested (0.5 mg: -0.43%) | ~70 |
| 4 mg (escalated) | -17.1% | -1.39% | ~70 |
| 8 mg (escalated) | -22.8% | -1.99% (2 mg start) / -1.88% (4 mg start) | ~70 |
| 12 mg (escalated) | -24.2% | -2.02% | ~62 |
| Placebo | -2.1% | -0.01% | ~70 |
Data from Phase 2 clinical trials (NCT04881760, NCT04867785).
Phase 3: TRIUMPH-4 (68 Weeks, Obesity + Knee OA, N=445)
| Dose | Weight Loss at 68 Weeks | Participants (approx.) |
|---|---|---|
| 9 mg | -26.4% | ~148 |
| 12 mg | -28.7% | ~148 |
| Placebo | ~-2% | ~149 |
Data from TRIUMPH-4 Phase 3 trial (Dec 2025, Eli Lilly press release). Additional endpoints: WOMAC pain reduction 74.3-75.8%; SBP -14.0 mmHg at highest dose.
Safety Data Summary (Phase 2/3)
| Adverse Event | Mild | Moderate | Severe | Placebo |
|---|---|---|---|---|
| Nausea | 26% | 8% | 1% | 4% |
| Diarrhea | 18% | 5% | <1% | 3% |
| Vomiting | 13% | 4% | <1% | 1% |
| Decreased appetite | 14% | 3% | 0% | 2% |
| Constipation | 8% | 2% | 0% | 3% |
| Injection site reaction | 5% | 1% | 0% | 2% |
| Dysesthesia | 3% | 1% | 0% | <1% |
Rates represent pooled estimates across dose groups from Phase 2 trials. GI adverse events were dose-dependent and generally transient with dose escalation.
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