TRIUMPH Program · Updated June 2026 · TRIUMPH-4 Data Reported
Retatrutide TRIUMPH Trials 2026: Phase 3 Status & Latest Readouts
Status of the four Phase 3 TRIUMPH trials evaluating retatrutide (LY3437943) across different obesity populations. NCT IDs, primary completion dates, expected readouts, and FDA submission projections. TRIUMPH-4 reported 28.7% weight loss at 68 weeks in December 2025 — the highest result ever recorded for a once-weekly injectable in a Phase 3 trial.
⚠ Investigational drug — not FDA-approved
Retatrutide is currently in Phase 3 clinical trials. It is not available by prescription and not approved for human use outside of clinical trials. This page is educational only.
🔎 Data Verification Note
NCT IDs and completion dates below are sourced from ClinicalTrials.gov and Eli Lilly investor disclosures as of June 2026. Items marked [verify] should be confirmed at clinicaltrials.gov for the most current status.
Phase 3 · Active, Not Recruiting
TRIUMPH-1
Retatrutide in Adults with Obesity or Overweight (with OSA and OA subsets)
NCT ID
NCT05929066
Primary Completion
April 2026
Enrollment
~2,300 participants
Primary Endpoint
% body weight change at Week 80
Population: Adults with obesity or overweight, without type 2 diabetes. Includes nested subsets for participants with knee osteoarthritis (GOA1) and obstructive sleep apnea (GSA1).
Design: 80-week randomized, double-blind, placebo-controlled basket trial; optional 24-week extension for ~500 participants. Master protocol J1I-MC-GZBJ.
Significance: Primary weight-management readout in non-diabetic obesity — the indication most relevant to the Wegovy/Zepbound market.
Phase 3 · Active, Not Recruiting
TRIUMPH-2
Retatrutide in Adults with Type 2 Diabetes Who Have Obesity or Overweight
NCT ID
NCT05929079
Primary Completion
Est. 2026–2027
Enrollment
18,558 participants
Primary Endpoints
HbA1c + weight loss
Population: Adults with type 2 diabetes and obesity or overweight. Includes an OSA subset (GSA2).
Design: 89-week randomized, double-blind, placebo-controlled study. Master protocol J1I-MC-GZBK.
Significance: The T2D readout that will determine whether retatrutide can compete with tirzepatide (Mounjaro) and semaglutide (Ozempic) in diabetes — historically a larger reimbursement market than obesity.
Phase 3 · Active, Not Recruiting
TRIUMPH-3
Retatrutide in Adults with Obesity and Established Cardiovascular Disease
NCT ID
Primary Completion
Est. 2028–2029
Population
Obesity + CVD
Primary Endpoint
% body weight change
Population: Adults with obesity and established cardiovascular disease — the same patient profile that semaglutide's SELECT trial used to win a cardiovascular risk-reduction label.
Significance: If TRIUMPH-3 shows MACE reduction, retatrutide could earn the same CV indication that drove Medicare coverage expansion for Wegovy in 2024.
Phase 3 · Primary Data Reported
TRIUMPH-4
Retatrutide in Adults with Obesity or Overweight and Knee Osteoarthritis
NCT ID
Readout
December 2025
Key Result
28.7% weight loss (12 mg, 68 wk)
Primary Endpoints
Weight + OA pain
Population: Adults with obesity or overweight and knee osteoarthritis.
Key result (Dec 2025): 28.7% mean body-weight loss at 68 weeks on 12 mg (26.6% placebo-adjusted), plus a 75% reduction in knee-OA pain scores — the highest weight-loss figure ever reported for a once-weekly injectable in a Phase 3 trial.
Safety signal to watch: Dysesthesia (abnormal skin sensation) reported in 8.8% of 9 mg patients and 20.9% of 12 mg patients vs ~0% on placebo. GI events typical for the class (nausea 43%, vomiting 21%, diarrhea 33%). Discontinuation: 12.2% (9 mg) and 18.2% (12 mg) vs 4% (placebo).
Note: Top-line data from Eli Lilly press release; full peer-reviewed publication pending. Source: Clinical Trials Arena, December 2025.
FDA Submission and Approval Timeline
| Milestone | Projected Date | Confidence | Notes |
|---|---|---|---|
| TRIUMPH-1/2/4 data completion | 2026–2027 | Medium | Based on enrollment rates and trial durations |
| NDA Submission to FDA | Q1–Q2 2027 | Analyst consensus | Pending TRIUMPH-1/2 readouts; not Lilly-confirmed |
| FDA Standard Review (~12 months) | 12 months from NDA | Standard process | Priority review may reduce to 6 months if granted |
| Potential FDA Approval | 2027–2028 | Analyst estimate | Not confirmed by FDA or Lilly; dependent on all milestones above |
How to Follow This Trial Program
- ClinicalTrials.gov retatrutide search — official trial registrations and updates
- Eli Lilly Investor Relations — quarterly earnings calls include pipeline updates
- Obesity Society meeting abstracts — key efficacy data typically presented at annual meetings before peer-reviewed publication
- NEJM, Lancet, and JAMA — Phase 3 primary publications expected 2026–2028
Sources and Verification
- ClinicalTrials.gov search for "retatrutide": https://clinicaltrials.gov/search?term=retatrutide
- Jastreboff AM, et al. "Triple–Hormone-Receptor Agonist Retatrutide for Obesity." NEJM 2023. https://www.nejm.org/doi/full/10.1056/NEJMoa2301972
- Eli Lilly pipeline disclosures: https://investor.lilly.com/pipeline
- TRIUMPH-4 top-line readout (December 2025): Clinical Trials Arena; ClinicalTrials.gov: NCT05931367. Primary peer-reviewed publication pending
- TRIUMPH program design overview: Jastreboff AM et al. Obesity (Silver Spring), 2025. PubMed 41090431
Frequently Asked Questions
How do I find an actively recruiting retatrutide trial?
ClinicalTrials.gov is the authoritative source — search NCT identifiers tagged 'retatrutide' or 'LY3437943'. Most TRIUMPH program trials are coordinated through major academic medical centers and contract research organization sites.
Am I eligible for a retatrutide trial?
Eligibility depends on the specific trial. Common inclusion criteria include BMI thresholds (typically ≥30, or ≥27 with comorbidities), age range (usually 18–75), and absence of contraindicated medical conditions (history of medullary thyroid cancer, MEN-2, pancreatitis, severe gastroparesis).
Will trial participants get the drug after the trial ends?
Open-label extension phases sometimes provide continued access through approval. Sponsor compassionate use programs may also be available post-trial. This is trial-specific and should be confirmed during the consent process.
Does it cost money to be in a clinical trial?
No. Phase 3 industry-sponsored trials cover all study-related costs and typically reimburse travel and time. Standard medical care costs not related to the trial remain the participant's responsibility.
What happens if I withdraw from a trial?
Participants can withdraw at any time without penalty. The sponsor provides standard-of-care transition support. Withdrawing does not affect access to other medications or future trial participation.