Effect of Tirzepatide and Bimagrumab on Body Composition, Insulin Sensitivity, and Bone in Adults With Obesity

Part of paid clinical trials in Boston, Massachusetts.

Sponsor
Massachusetts General Hospital
Study ID
NCT05933499
Phase
PHASE2
Status
Recruiting
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Conditions

Eligibility Criteria

Sex
ALL
Age
18 Years - N/A
Healthy Volunteers
Not accepted

Interventions

  • Bimagrumab — DRUG
    SQ bimagrumab 300mg qweek
  • Tirzepatide — DRUG
    SQ tirzepatide 15mg qweek
  • Calcium/Vitamin D — DIETARY_SUPPLEMENT
    Elemental calcium 1200 mg + vitamin D3 800 IU PO daily
  • Lifestyle and nutrition counseling — BEHAVIORAL
    Lifestyle and nutrition counseling consistent with current guidelines for weight management

Study Details

In adults with obesity seeking treatment, weight loss would ideally be composed almost exclusively of fat mass. However, loss of muscle mass and bone are unintentional consequences of weight loss, which may have negative effects on health by lessening improvements in glucose and insulin levels, reducing resting metabolic rate, and increasing the risk of falls and fractures. Data in animals and humans suggest that bimagrumab, an investigational new drug for obesity that inhibits the activin type II receptor (ActRII) inhibitor, may help maximize loss of fat mass while maintaining muscle mass when used in combination with a glucagon-like peptide 1 receptor agonist (GLP-1 RA). The investigators hypothesize that in a randomized, placebo-controlled trial of 63 adults with obesity randomized to tirzepatide (GLP-1/GIP RA) + bimagrumab, tirzepatide alone, or bimagrumab alone, the combination of tirzepatide + bimagrumab will result in improvements in muscle, fat, and bone compared to tirzepatide alone or bimagrumab alone when given in addition to a lifestyle intervention for weight loss over 52 weeks.

Key Dates

Start date
Nov 5, 2025
Status verified
Mar 2026
Primary completion
Dec 31, 2028
Completion
Mar 31, 2029

Study Design

Enrollment
63 participants (estimated)
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT

Arms

  • Experimental: Tirzepatide + bimagrumab
  • Active Comparator: Tirzepatide + placebo
  • Active Comparator: Bimagrumab + placebo

Primary Outcome Measure

Change in number of kilograms of lean mass by dual-energy x-ray absorptiometry [ Time Frame: 52 weeks ]

Central Contacts

Locations (1)

FacilityCityStateZIPSite coordinators
Massachusetts General HospitalBostonMassachusetts02114
Melanie Haines, MD
[email protected]
617-726-3870

Find similar trials in Boston, MA

By condition
Obesity / overweight
By specialty
EndocrinologyMetabolic healthWeight loss
By research site
Massachusetts General Hospital· Boston, MA

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