Effect of Tirzepatide and Bimagrumab on Body Composition, Insulin Sensitivity, and Bone in Adults With Obesity
Massachusetts General Hospital
Summary
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.
Eligibility
- Age range
- 18+ years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * BMI ≥30 kg/m2 or ≥27kg/m2 with at least one weight-related medical condition * Have a history of at least one self-reported unsuccessful behavioral effort to lose body weight * Have an established primary care provider Exclusion Criteria: * Current or prior history of diabetes mellitus based on self-report, use of diabetes medications, HbA1c ≥6.5%, or fasting glucose ≥126 mg/dL * Any single serum transaminase level (i.e., ALT, AST, alk phos) ≥3x the upper limit of normal (ULN) * Serum lipase and/or amylase levels ≥2x ULN * Serum bilirubin level \>1.6 mg/dL * Chronic ki…
Interventions
- DrugBimagrumab
SQ bimagrumab 300mg qweek
- DrugTirzepatide
SQ tirzepatide 15mg qweek
- Dietary SupplementCalcium/Vitamin D
Elemental calcium 1200 mg + vitamin D3 800 IU PO daily
- BehavioralLifestyle and nutrition counseling
Lifestyle and nutrition counseling consistent with current guidelines for weight management
Location
- Massachusetts General HospitalBoston, Massachusetts