Study of Safety, Tolerability, and Pharmacokinetics of REGN2477 Alone and in Combination With REGN1033 in Healthy Postmenopausal Women and Healthy Adult Men

A Randomized, Double-Blind, Placebo-Controlled, Ascending Dose Study to Assess the Safety, Tolerability, and Pharmacodynamic Effects of REGN2477 Alone and in Combination With REGN1033 in Healthy Postmenopausal Women and Healthy Adult Men

The primary objective is to assess the safety and tolerability of REGN2477 alone and combined with REGN1033.

The secondary objectives are to:

• Assess the effect of REGN2477 alone, REGN1033 alone, and REGN2477 + REGN1033 in combination on thigh muscle volume
• Assess the effects of REGN2477 alone, REGN1033 alone, and REGN2477 + REGN1033 in combination on total and regional body composition
• Evaluate the Pharmacokinetic (PK) profile of REGN2477 and REGN1033
• Assess immunogenicity of REGN2477 or REGN1033
• Assess REGN2477 or REGN1033 target engagement

Key Inclusion Criteria:

• Postmenopausal women age 45 to 70 years and age 35 to 60 years inclusive for men not intending to father children
• BMI between 18 to 32 kg/m2, inclusive
• Willing and able to maintain current diet, supplements and physical activity level throughout the study
• Provides signed informed consent

Key Exclusion Criteria:

• Significant illness or history of significant illness
• Contraindication to MRI
• History of human immunodeficiency virus (HIV); hepatitis B or hepatitis C virus (HCV)
• History of immobilization, major surgical procedure, fracture, or major trauma within 9 months prior to screening
• History of significant gynecological disorders or malignancies; history of breast malignancies (uterine fibroids or dysfunctional uterine bleeding is acceptable)
• Inconsistent vigorous physical activity (on fewer than 5 days per week), such as intermittent weight lifting
• History of hypersensitivity reactions to tetracycline antibiotics (includes doxycycline), vaccines, or biologics
• Use of agents that alter muscle mass that have not been at a stable dose for 3 months prior to screening (includes protein supplements), or use of any weight altering or anabolic steroid drugs (includes drugs for obesity, diuretics, testosterone)
• Participants treated with a biologic therapy or biologic immunotherapy in the previous 12 weeks prior to screening and during the study

Note: Other protocol Inclusion/Exclusion criteria apply.