Safety and Efficacy of REGN2477+REGN1033 in Patients With Sporadic Inclusion Body Myositis

A Phase 2 Randomized, Double-Blind, Placebo-Controlled Study of the Safety and Efficacy of Intravenously Administered REGN2477+REGN1033 in Patients With Sporadic Inclusion Body Myositis

The primary objective of the study is to evaluate the efficacy of REGN2477+REGN1033 in combination on total lean mass, as measured by Dual-energy X-ray absorptiometry (DXA) in patients with sporadic inclusion body myositis (sIBM).

The secondary objectives of the study are:

• To evaluate the efficacy of REGN2477+REGN1033 on the IBM-Functional Rating Scale (IBM-FRS)
• To evaluate the efficacy of REGN2477+REGN1033 on the sIBM Physical Functioning Assessment (sIFA)
• To evaluate the safety and tolerability of REGN2477+REGN1033
• To evaluate the effects of REGN2477+REGN1033 on body composition by DXA, including appendicular lean mass and total fat mass
• To evaluate the efficacy of REGN2477+REGN1033 on measures of muscle performance and physical function
• To evaluate the efficacy of REGN2477+REGN1033 on patient reported outcome measures including the fear of falling, falls and near falls, and health-related quality of life
• To evaluate the pharmacokinetic(s) (PK) profile of REGN2477+REGN1033, including functional REGN2477 and functional REGN1033 concentrations in serum over time
• To evaluate the immunogenicity of REGN2477+REGN1033

Key Inclusion Criteria:

• Men and postmenopausal* women
• Diagnosed with sIBM based on the European Neuromuscular Centre (ENMC) IBM Research Diagnostic Criteria
• Ability to walk ≥150 meters, with or without a walking aid such as cane or walker, in 6 minutes.
• Ability to climb 4 steps of stairs unassisted (may use handrails)
• Willing and able to comply with clinic visits and study-related procedures

Key Exclusion Criteria:

• Other neurological conditions (eg, hemiplegia post stroke, Parkinson's) or musculo-skeletal conditions (eg, severe osteoarthritis) causing mobility impairment
• Mini-Mental State Examination (MMSE) score <24
• Ongoing, chronic, high-dose (>20 mg prednisone equivalent per day), systemic corticosteroid therapy within 6 weeks prior to screening.
• Any condition that precludes adequate intake of energy and protein; malnutrition; presence of an eating disorder.
• Unintentional weight loss of ≥10% in the past 6 months (patient-reported)
• Hospitalization for heart failure in last year or New York Heart Association Class 4
• History of hypertrophic cardiomyopathy
• Any drugs known to influence muscle mass and performance such as anabolic steroids or growth hormone within 6 weeks prior to screening
• Unable to fit on the site's DXA scanner table, within borders for scanning of total lean mass

Note: Other protocol Inclusion/Exclusion criteria apply