Clinical Scorecard: Retatrutide for Obesity, Knee Osteoarthritis Pain, and Obstructive Sleep Apnea

At a Glance

Key Highlights

• At week 80, mean weight decreased by 17.6%, 23.7%, and 25% with retatrutide 4 mg, 9 mg, and 12 mg, respectively, versus 3.9% with placebo.
• In participants with knee osteoarthritis, mean pain scores decreased by 3.5 points with 9 mg and 3.6 points with 12 mg, versus 1.9 points with placebo.
• In participants with obstructive sleep apnea, mean apnea-hypopnea index decreased by 34.3 events per hour with 9 mg and 31.7 with 12 mg, versus 9.9 with placebo.
• Retatrutide improved several cardiometabolic measures, including systolic blood pressure, triglycerides, and non-HDL cholesterol at the 12-mg dose.
• Gastrointestinal adverse events were most frequent, particularly during dose escalation; adverse-event-related discontinuation was 11.1% with 12 mg versus 4.6% with placebo.

Guideline-Based Recommendations

Diagnosis

• The trial defined eligibility as BMI of at least 30, or BMI 27 to less than 30 with at least one obesity-related complication.
• Knee osteoarthritis pain was assessed using the WOMAC pain subscale; obstructive sleep apnea severity was assessed using the apnea-hypopnea index.

Management

• The study evaluated once-weekly subcutaneous retatrutide at 4-mg, 9-mg, and 12-mg doses for 80 weeks; it did not provide a clinical practice guideline or establish a preferred dose.
• The protocol permitted dose reductions for gastrointestinal adverse events, inadequate food or fluid intake, low BMI, or excessive weight loss.

Monitoring & Follow-up

• The trial reported gastrointestinal events, dysesthesia, injection-site reactions, hypotension, and urinary tract infections; hypotension was more common among participants taking antihypertensive medications.
• The study assessed body weight, knee pain, sleep apnea severity, cardiometabolic measures, and physical functioning.

Risks

• Nausea, diarrhea, constipation, and vomiting were more frequent with retatrutide than placebo; most gastrointestinal events were mild or moderate and transient.
• Serious adverse events occurred in 7.7% to 10.5% of retatrutide recipients and 5.5% of placebo recipients.
• The trial was not powered to assess cardiovascular safety; the authors noted that longer-term studies are needed to evaluate cardiovascular outcomes.

Patient & Prescribing Data

The trial enrolled 2,339 adults without diabetes with obesity or overweight plus an obesity-related complication. Mean baseline BMI was 40; 77.4% had BMI of at least 35.

At week 80, mean weight loss was 17.6% with 4 mg, 23.7% with 9 mg, and 25% with 12 mg, versus 3.9% with placebo. Adverse-event-related discontinuation increased with dose: 4.1%, 6.5%, and 11.1%, respectively, versus 4.6% with placebo.

Clinical Best Practices

• Interpret the findings in light of the trial population: only 2% of participants had baseline BMI below 30.
• Consider that the trial had no active comparator, so it did not directly compare retatrutide with established obesity medications.
• The authors stated that the findings raise questions about whether the maximum tolerated dose is always necessary; the trial did not establish a dose-selection recommendation.
• The study was funded by Eli Lilly, which conducted trial monitoring and data collection and analysis; several authors were Eli Lilly employees.

Related Resources & Content

• New England Journal of Medicine — TRIUMPH-1 trial (as cited in the source article)