- Preclinical data show that SRK-439 increased lean mass and lowered fat mass gain in mice receiving metformin
- Data support that Scholar Rock’s unique approach to selective myostatin inhibition could improve body composition in people living with obesity and on an existing background treatment
- Scholar Rock’s industry-leading anti-myostatin portfolio includes SRK-439 and apitegromab, the first investigational anti-myostatin therapy to show improved motor function in Spinal Muscular Atrophy (SMA) in a Phase 3 trial
- Obesity program progressing with Phase 2 EMBRAZE trial on track for readout in Q2 2025
CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Scholar Rock (NASDAQ: SRRK), a late-stage biopharmaceutical company focused on advancing innovative treatments for spinal muscular atrophy (SMA), cardiometabolic disorders, and other serious diseases where protein growth factors play a fundamental role, today announced new preclinical data that support the potential of SRK-439, a highly selective investigational antimyostatin antibody, to increase lean mass and lower fat mass gain when taken with metformin. These data will be presented by Melissa Fulham, Ph.D., of Scholar Rock, at the ObesityWeek conference in San Antonio, Texas on November 5.
“These new data build upon a robust body of evidence demonstrating the potential of selective myostatin inhibition as an important therapeutic approach,” said Jay Backstrom, M.D., MPH, President and Chief Executive Officer at Scholar Rock. “These latest SRK-439 data support our hypothesis that a highly selective approach to targeting myostatin inhibition could have positive effects on body composition in people living with obesity and associated comorbidities like diabetes, and also underscore the value within Scholar Rock’s platform. We are looking forward to providing more updates on the exciting advancements in our cardiometabolic program, including our Phase 2 EMBRAZE trial topline data in the second quarter of 2025.”
Preclinical study design
The research study tested a murine equivalent of SRK-439 in a diet-induced obesity (DIO) mouse model. All mice were given a high-fat diet, followed by either metformin (50 mg/kg daily) or control (water) for four weeks. Following that four-week period, mice in metformin and control groups were given either an IgG control antibody (10 mg/kg weekly) or SRK-439 (10 mg/kg weekly for younger mice and 3 mg/kg weekly for older mice) for another four weeks. To assess whether effects were persistent across age ranges, this study design was repeated in two age groups: both young (10-week-old) and mature (22-week-old) DIO mice.
Quantitative nuclear magnetic resonance (qNMR) was used to analyze change in lean mass at baseline, after four weeks of metformin treatment, and every two weeks following treatment with SRK-439 or IgG control.
Changes in body composition in the presence or absence of metformin
The group that received SRK-439 on the background of metformin showed a significant increase in lean mass versus the group receiving metformin alone, and this result was consistent across age groups. Key findings supporting the potential for SRK-439 in advancing healthier weight management include:
- Young animals treated with SRK-439 and metformin demonstrated a 2-fold increase in lean mass over the duration of the study compared to the lean mass increase in the metformin group and in IgG controls (31.6% increase from baseline vs. 15.1%, p