SURMOUNT-J

Study record

Population

Japanese adults without diabetes: BMI ≥27 with at least two qualifying obesity-related disorders, or BMI ≥35 with at least one. Of 267 randomized participants, 225 remained in the modified intention-to-treat population after one site was excluded: 73/77/75 in the 10 mg/15 mg/placebo groups. Do not treat all 267 as the analyzed cohort.

Read source · Abstract-level extractionPrimary abstract — Methods and Findings

Formulation

Single-use injection pens for tirzepatide and matching placebo; this is not a compounded-vial study.

Read source · Study protocolProtocol synopsis, printed page 17

Route

Once-weekly subcutaneous administration in each study arm.

Read source · Study protocolProtocol synopsis, printed page 17

Dose & frequency

Tirzepatide started at 2.5 mg weekly, with 2.5 mg increases every four weeks to 10 or 15 mg; placebo followed matching steps. This is the assigned trial regimen, not a personal starting dose or cycling plan.

Read source · Study protocolProtocol synopsis, printed page 17

Study design

Randomized, blinded placebo comparison with lifestyle modification. The efficacy estimand excludes data after treatment discontinuation; continuous weight change uses MMRM adjusted for baseline weight, health disorders and sex. It estimates continued-treatment efficacy, not weight change after stopping.

Read source · Study protocolSAP sections 1.1.2.1 and 4.3.2.1, printed pages 15 and 22–23

Duration

72-week treatment period, including escalation, followed by four weeks off drug for safety follow-up.

Read source · Study protocolProtocol study design, section 4.1

Reported findings

At week 72, registry mean weight changes were −17.8%, −22.7% and −1.7% for 10 mg, 15 mg and placebo; posted evaluable denominators were 59/65/66. The ≥5% weight-loss endpoint instead used 71/76/75, with 94.37%/96.05%/20% responders. Both exclude the identified site. Do not substitute randomized denominators or confuse within-arm changes with placebo-adjusted differences.

Read source · Registry resultsCoprimary registry outcomes — MMRM description, populations, denominators and estimates

Adverse events

Registry serious-event counts were 8/73, 5/77 and 5/75 for 10 mg, 15 mg and placebo; no deaths were reported in these groups. These are all-cause observations, not treatment-attributed events. Complete nonserious-event and withdrawal reconciliation with the publication remains pending.

Inspect extraction gap · Registry resultsRegistry adverse events — group totals

Monitoring

Planned assessments included physical examination, vital signs, ECGs, laboratory tests, and depression/suicidality screening with PHQ-9 and C-SSRS. Clinically significant abnormal laboratory values during treatment or four weeks after the last dose were to be repeated until resolved, back to baseline or no longer clinically significant. These are trial procedures, not evidence that the drug caused the conditions being monitored. The trial also prescribed dietary counseling and at least 150 minutes of activity weekly; detailed meal and appetite measurements required additional participant agreement.

Read source · Study protocolProtocol sections 8.2.1–8.2.5, printed pages 79–83; sections 5.3.1–5.3.3 pp60–61 and 8.1.2.9.5 pp76–77