Phase 2 Study Evaluating Apitegromab for the Treatment of FSHD

Inclusion Criteria

• Male or female participants, 18 to 60 years of age at the time of informed consent.
• Genetic diagnosis of FSHD Type 1 or FSHD Type 2, confirmed with the appropriate documentation from an accredited laboratory
• Clinical severity score of 1.5 to 3.0 (Ricci score; range 0 to 5), inclusive, at screening
• Baseline 10-meter walk/run test time ≤5 seconds

Exclusion Criteria

• Prior history of a hypersensitivity reaction to a mAb or recombinant protein bearing an Fc domain (eg, a soluble receptor-Fc fusion protein), apitegromab, or excipients of apitegromab
• Treatment with other investigational drugs in a clinical trial within 3 months or 5 half-lives, whichever is longer, before screening
• Previous treatment with apitegromab, or with other anti-myostatin therapies, including activin receptor antagonists
• Current or prior use of anabolic steroids, growth hormones, glucagon-like peptide-1 receptor agonist or other substances with known effects on muscle.
• Use of therapies with potentially significant muscle effects (eg, androgens, insulin-like growth factor, growth hormone, systemic beta-agonist, botulinum toxin, or muscle relaxants or muscle-enhancing supplements) or potentially significant neuromuscular effects (eg, acetylcholinesterase inhibitors) within 60 days before screening
• Use of systemic or corticosteroids within 60 days prior to screening. Inhaled or topical steroids are allowed.
• Pregnant or breastfeeding.
• Contraindications for MRI that may include, but are not limited to, certain implanted electronic devices, cochlear implants, metallic foreign bodies, vascular clips, and metallic implants; or claustrophobia, contrast agent allergies, inability to lie still, or external medical devices that may not be removed.
• History of alcoholism, or illicit drug use (drugs that are illegal and have not been prescribed).
• Taking medications that impede coagulation or platelet aggregation or has a history or active coagulopathy disorder.
• Any acute or comorbid condition interfering with the well-being of the participant within 7 days prior to screening, including active systemic infection, the need for acute treatment, or inpatient observation due to any reason