A Phase 1 Single- and Multiple-Ascending Dose Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of SRK-439 in Healthy Adults

Key Inclusion Criteria: 1. Male or female participants, ≥18 to ≤55 years of age, at the time of informed consent 2. BMI of ≥18 kg/m2 to ≤35 kg/m2 (inclusive) at screening Exclusion Criteria: 1. Previous treatment with SRK-439 or apitegromab, or with other anti-myostatin therapies, including ACTR antagonists. 2. History of immunosuppressive, chemotherapeutic, or radiation treatment within 12 months prior to screening. 3. Current or prior use of anabolic steroids, growth hormones, or other substances with known effects on muscle. 4. Use of therapies with potentially significant muscle effects…