A Study to Assess Efficacy, Safety, Tolerability, Pharmacokinetics (PK) and Pharmacodynamics (PD) of RO7204239 in Combination With Tirzepatide in Participants With Obesity or Overweight With At Least One Weight-related Comorbidity

What Was Tested

The trial (phase 2) is built around Tirzepatide.

The study comprises of a 4-week screening period; a 48-week core treatment period, where all participants will receive tirzepatide as background treatment and will be randomized to one of the 4 treatment arms; a 24-week treatment extension period, where participants will stop treatment with tirzepatide and a 24-week post-treatment follow-up (FU) period.

It had four arms (groups): Placebo + Tirzepatide (active comparator), one (experimental), one (experimental) and one (experimental).

Participants will receive RO7204239 matching placebo via subcutaneous (SC) injection every 4 weeks (Q4W) for the core treatment period of 48 weeks and the treatment extension period of 24 weeks. Participants will also receive tirzepatide, as a background therapy, up-titrated according to the approved tirzepatide prescribing information, SC, every week (QW) during the core treatment period of 48 weeks.

The registry classes the interventions as drug.

Who Took Part

The registry lists 285 actual participants took part.

It was open to people of any sex aged from 18 years with no upper age limit.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: BMI ≥ 30.0 kilograms per square meter (kg/m²) (additional weight-related comorbidities are not required for inclusion). BMI ≥ 27.0 kg/m² and \< 30.0 kg/m² with at least one weight-related comorbidity such as: hypertension, dyslipidemia, obstructive sleep apnea and any cardiovascular disease. History of at least one self-reported unsuccessful dietary or exercise effort to lose body weight. Weight stability: self-reported change in body weight less than 5 kilograms (kg) (11 pounds \[lbs\]) within 3 months prior to screening.

The full record lists 4 inclusion and 15 exclusion criteria; among the exclusions: prior history or diagnosis of dm; presence of non-proliferative diabetic retinopathy requiring acute therapy, proliferative diabetic retinopathy or diabetic macular edema; have obesity induced by other endocrinologic disorders.

How the Study Was Run

Design: randomized, parallel-group and quadruple-blind.

The participants were allocated by chance, so the Tirzepatide group and the comparison group should start out alike.

The Tirzepatide group and the comparison group ran side by side rather than switching.

As a double-blind Tirzepatide study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2025-05-05 with completion listed for 2026-09-03.

It ran at 35 sites in United States (19), Spain (6), United Kingdom (6) and Poland (4).

Its stated primary purpose is treatment.

What Was Measured

Researchers chose this as the main measure: Percent Change From Baseline in Body Weight (time frame: Baseline, Week 48).

It also tracked 25 secondary outcomes, for example Absolute Change From Baseline in Body Weight, Change From Baseline in Body Mass Index (BMI), Change From Baseline in Waist-to-height Ratio, Change From Baseline in Waist Circumference, Change From Baseline in Total Body Fat Mass Measured by Dual-energy X-ray Absorptiometry (DXA) and Change From Baseline in Total Lean Body Mass Measured by DXA.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Tirzepatide in 285 people.

Its status is active not recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Tirzepatide compound page, all human trials.