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Retatrutide · Phase 3 · Completed

TRIUMPH-4

In TRIUMPH-4, a phase 3 trial of retatrutide in adults with obesity or overweight and knee osteoarthritis, without diabetes (n=445), mean body weight fell 26.4% on 9 mg and 28.7% on 12 mg over 68 weeks, against 2.1% on placebo (efficacy estimand; Eli Lilly topline release, 11 December 2025).

Primara Labs sells some of the compounds covered here. Every figure on this page links to its source and the date it was checked.

Results

TRIUMPH-4: mean percent change in body weight by armTRIUMPH-4 efficacy estimand9 mg-26.4%12 mg-28.7%Placebo-2.1%
Mean percent change in body weight by arm, as each source reports it. Bars from different trials are not a head-to-head comparison: populations, durations and estimands differ.

WOMAC pain fell 4.5 and 4.4 points from a baseline of 6.0 on 9 and 12 mg, against 2.4 on placebo.

Side effects reported

In TRIUMPH-4, discontinuation because of adverse events was 12.2% on 9 mg and 18.2% on 12 mg, against 4.0% on placebo. The most frequently reported adverse events were nausea in 38.1% on 9 mg and 43.2% on 12 mg against 10.7% on placebo, diarrhoea in 34.7% on 9 mg and 33.1% on 12 mg against 13.4% on placebo, constipation in 21.8% on 9 mg and 25.0% on 12 mg against 8.7% on placebo and vomiting in 20.4% on 9 mg and 20.9% on 12 mg against 0.0% on placebo.

Event9 mg12 mgPlacebo
Discontinuation for adverse events12.2%18.2%4.0%
Nausea38.1%43.2%10.7%
Diarrhoea34.7%33.1%13.4%
Constipation21.8%25.0%8.7%
Vomiting20.4%20.9%0.0%
Decreased appetite19.0%18.2%9.4%
Dysesthesia8.8%20.9%0.7%

Design

Trial design and sources

Compound
Retatrutide
Phase
3
Population
Adults with obesity or overweight and knee osteoarthritis, without diabetes
Participants randomised
445
Duration
68 weeks
Primary endpoint
Co-primary: percent change in body weight and change in WOMAC pain score at 68 weeks
Estimand
efficacy
Read out
11 December 2025
  • Eli Lilly topline release, 11 December 2025 open · checked 23 September 2026
  • ClinicalTrials.gov NCT05931367 open · checked 23 September 2026
  • Registry: NCT05931367

Questions

TRIUMPH-4, answered

What did TRIUMPH-4 find?

In TRIUMPH-4, a phase 3 trial of retatrutide in adults with obesity or overweight and knee osteoarthritis, without diabetes (n=445), mean body weight fell 26.4% on 9 mg and 28.7% on 12 mg over 68 weeks, against 2.1% on placebo (efficacy estimand; Eli Lilly topline release, 11 December 2025).

What side effects were reported in TRIUMPH-4?

In TRIUMPH-4, discontinuation because of adverse events was 12.2% on 9 mg and 18.2% on 12 mg, against 4.0% on placebo. The most frequently reported adverse events were nausea in 38.1% on 9 mg and 43.2% on 12 mg against 10.7% on placebo, diarrhoea in 34.7% on 9 mg and 33.1% on 12 mg against 13.4% on placebo, constipation in 21.8% on 9 mg and 25.0% on 12 mg against 8.7% on placebo and vomiting in 20.4% on 9 mg and 20.9% on 12 mg against 0.0% on placebo.