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CompletedNCT06445075EMBRAZEUpdated Jan 23, 2026

Efficacy and Safety of Apitegromab for the Treatment of Adults Who Are Overweight or Obese

A Phase 2 interventional study of Apitegromab and Placebo in Overweight and Obesity, sponsored by Scholar Rock, Inc.. Completed at 7 sites in United States. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-23.

Sponsored by Scholar Rock, Inc. · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
102
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

A phase 2 study to evaluate the effects of apitegromab as an adjunctive therapy to GLP-1 receptor agonist therapy in subjects with overweight or obesity

Read the detailed description

This phase 2 randomized, double-blind, placebo-controlled, multicenter study assessed the safety, efficacy, and pharmacokinetics (PK) of apitegromab when used as an adjunctive therapy to GLP-1 receptor agonist therapy in subjects with overweight and obesity and without diabetes. Each subject received tirzepatide throughout the treatment period. In addition, all subjects were randomized 1:1 to receive either apitegromab or placebo during the treatment period.

02

Conditions studied

  • Overweight and Obesity

Keywords

  • Overweight
  • Obesity
03

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Able to comprehend the informed consent process and provide written informed consent prior to study enrollment and the conduct of any study-related assessments to study enrollment and the conduct of any study-related assessments
  • Male or female, age ≥ 18 and ≤ 65 years at the time of informed consent
  • Stable body weight (±5 kg) within 90 days of Screening
  • At Screening, a BMI of:

    1. ≥30.0 kg/m2 to ≤45.0 kg/m2 or
    2. ≥27.0 kg/m2 to \<30.0 kg/m2 with the presence of 1 or more weight-related comorbid condition(s). Note: See exclusion criteria for specific organ class disease parameters

Exclusion criteria

Exclusion Criteria:

  • History of or active cardiovascular, neurovascular, peripheral vascular, pulmonary, hepatic, pancreatic, neuromuscular, and/or psychiatric disease
  • Active malignancy, other than local subcutaneous squamous cell and basal cell carcinomas
  • History of immunosuppressive, chemotherapeutic, or radiation treatment within 12 months prior to Screening
  • History of Type 1 diabetes or active Type 2 diabetes (T2D). If there was a history of T2D and it resolved, then the resolution must have occurred >12 months prior to Screening. Prediabetes managed with nonpharmacologic approaches (exercise and diet) is not an exclusion
04

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
102 participants (actual)

Study arms

  • Experimental
    Cohort 1

    Apitegromab + incretin mimetic

    Drug: Apitegromab · Drug: Tirzepatide

  • Placebo comparator
    Cohort 2

    Placebo + incretin mimetic

    Drug: Placebo · Drug: Tirzepatide

Interventions

  • DrugApitegromab

    Apitegromab (SRK-015) is a fully human anti-proMyostatin monoclonal antibody (mAb) that specifically binds to human pro/latent myostatin, inhibiting myostatin activation. Apitegromab was administered every 4 weeks by intravenous (IV) infusion.

    Also known as: SRK-015

  • DrugPlacebo

    Same appearance and composition as apitegromab drug product but does not contain the active ingredient. Placebo was administered every 4 weeks by intravenous (IV) infusion.

  • DrugTirzepatide

    Glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist. Tirzepatide was administered every week by subcutaneous injection.

    Also known as: ZEPBOUND

05

What researchers measure

Primary outcomes

  1. Change from Baseline in total Lean Body Mass (kg) at 24 weeks

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

Secondary outcomes

  1. Change from Baseline in body weight

    Total body weight was assessed via a calibrated scale

    Time frame: Baseline and 24 weeks

  2. Change from Baseline in percent lean body mass (%)

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

  3. Change from Baseline in fat body mass (kg and %)

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

  4. Change from Baseline in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and trunk fat body mass (kg and %)

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

  5. Percent (%) of weight loss from baseline due to fat body mass loss

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

  6. Percent (%) of weight loss from baseline due to lean body mass loss

    Dual-energy X-ray absorptiometry was used to evaluate body composition

    Time frame: Baseline and 24 weeks

  7. Concentration of apitegromab in circulation over time

    Blood samples were assessed for circulating concentration of apitegromab

    Time frame: Baseline up to 40 weeks

  8. Concentration of latent myostatin in circulation over time

    Blood samples were assessed for circulating concentration of latent myostatin

    Time frame: Baseline up to 24 weeks

  9. Treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)

    Incidence and severity of TEAEs and SAEs

    Time frame: Baseline up to 40 weeks

  10. Presence of anti-drug antibodies (ADA) against apitegromab over time

    Measured in serum blood samples

    Time frame: Baseline up to 40 weeks

Other outcomes

  1. Change from Baseline in HbA1c

    Blood samples were assessed for HbA1c (glycated hemoglobin)

    Time frame: Baseline up to 32 weeks

  2. Change from baseline in fasting serum triglycerides

    Blood samples were assessed for fasting serum triglycerides

    Time frame: Baseline up to 32 weeks

  3. Change from baseline in total cholesterol

    Blood samples were assessed for total cholesterol

    Time frame: Baseline up to 32 weeks

  4. Change from baseline in low-density lipoprotein cholesterol (LDL-C)

    Blood samples were assessed for low-density lipoprotein cholesterol (LDL-C)

    Time frame: Baseline up to 32 weeks

06

Study locations

7 sites
  • ProSciento CRU
    Chula Vista, California 91911, United States
  • AdventHealth Translational Research Institute
    Orlando, Florida 32804, United States
  • Great Lakes Clinical Trials, LLC d/b/a Flourish Research
    Chicago, Illinois 60640, United States
  • Tandem Clinical Research GI, LLC
    Marrero, Louisiana 70072, United States
  • Alliance for Multispecialty Research, LLC
    Norman, Oklahoma 73069, United States
  • Apex Mobile Clinical Research
    Bellaire, Texas 77401, United States
  • Clinical Trials of Texas, LLC dba Flourish Research
    San Antonio, Texas 78229, United States
07

References and documents

Publications

  • Pratley RE, Denham DS, Trivedi R, Watkins E, Connery L, Barnes J, Yu D, Hong J, Simard C, Umans K, Liu L, Tirucherai GS, Marantz JL. Apitegromab for lean mass preservation during tirzepatide-induced weight loss: a randomized, double-blind, placebo-controlled phase 2 trial. Nat Med. 2026 Jun 8. doi: 10.1038/s41591-026-04440-4. Online ahead of print. PubMed 42260100 ↗

Individual participant data

Plan to share: Yes

08

Registry details

Key details

Study ID
NCT06445075
Lead sponsor
Scholar Rock, Inc.
Responsible party
Sponsor
First posted
Jun 6, 2024
Start date
May 21, 2024
Primary completion
Mar 4, 2025
Completion
Jun 17, 2025
Last update
Jan 23, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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