A Study to Investigate the Safety and Efficacy of RO7204239 in Combination With Risdiplam (RO7034067) in Participants With Spinal Muscular Atrophy

Risdiplam works by helping the body produce more survival motor neuron (SMN) protein throughout the body. This means fewer motor neurons - nerve cells that pass impulses from nerves to muscles to cause movement - are lost, which may improve how well muscles work in people with SMA. RO7204239 is an investigational anti-myostatin antibody that is designed to target myostatin. Myostatin plays an important role in the regulation of skeletal muscle size by controlling growth. Inhibiting myostatin may help muscles grow in size and strength. RO7204239 in combination with risdiplam, which is designed to increase the amount of SMN protein throughout the body, has the potential to further improve motor function and clinical outcomes for people living with SMA. This trial will study the safety and efficacy of RO7204239 in combination with risdiplam in patients with spinal muscular atrophy (SMA). The trial has two parts; Part 1 is the dose-finding part in SMA patients that are either ambulant (aged 2-10 years) or non-ambulant (aged 5-10 years) within separate cohorts, and Part 2 is the pivotal part in SMA patients aged 2-25 years that are ambulant.

NCT Number	NCT05115110
Lead Sponsor	Hoffmann-La Roche
Conditions	Spinal Muscular Atrophy (SMA)
Enrollment	259 participants
Start Date	2022-06-02
Primary Completion	2026-10-28 (estimated)
Study Completion	2026-10-28 (estimated)
Updated on ClinicalTrials.gov	2026-06-11