A Phase 2, Multicenter, Randomized, Placebo-controlled, Double-blind Study to Investigate the Safety, Pharmacodynamics, and Preliminary Efficacy of S-606001 as an Add-on to Enzyme Replacement Therapy in Patients With Late-onset Pompe Disease

Key Inclusion Criteria: * Participant must be ≥18 years of age and ≥40 kilograms (kg) of body weight at the time of signing the informed consent. * Participant must have a diagnosis of LOPD based on documentation of 1 of the following: 1. Deficiency of acid alpha-glucosidase (GAA) enzyme 2. GAA genotype * Participant has a %FVC ≥30% and ≤80% in an upright position without mechanical ventilation at screening; or Participant has ≥10% %FVC drop from upright position to supine position and %FVC ≥20% in a supine position. * Participant performs the 6MWT at screening, as determined by the clin…