A Study of CK-2127107 in Patients With Spinal Muscular Atrophy

CY 5021 is a Phase 2, double-blind, randomized, placebo-controlled, multiple dose study of reldesemtiv in 2 sequential ascending dose cohorts of patients with SMA. Patients will be randomized 2:1 to receive reldesemtiv or placebo twice daily for 8 weeks. Patients randomized to reldesemtiv in Cohort 1 will receive a dose of 150 mg twice daily and patients randomized to reldesemtiv in Cohort 2 will receive 450 mg twice daily. Within each cohort, randomization will be stratified by ambulatory status (ambulatory versus non ambulatory). The primary objective of the study is to determine the PD effects of reldesemtiv on measures of pulmonary function, respiratory function, muscle strength, and motor function. Other PD measures include changes in the timed up and go (TUG) test, a 6-minute walk test (6MWT), and patient and investigator global assessments. Secondary objectives include the safety of multiple doses of reldesemtiv and an evaluation of the pharmacokinetics of reldesemtiv.