Apitegromab Shows Promise in Enhancing Motor Function in Spinal Muscular Atrophy Patients

Recent research published in the Lancet Neurology highlights the potential of apitegromab, a monoclonal antibody that inhibits myostatin activation, in improving motor function among patients with nonambulatory type 2 or type 3 spinal muscular atrophy (SMA). SMA is a genetic disorder characterized by progressive muscle weakness and degeneration, affecting motor skills and mobility.

In a phase 3 clinical trial conducted at 48 hospitals, researchers evaluated the safety and effectiveness of apitegromab in young patients aged 2 to 21 years who were already receiving standard treatments like nusinersen or risdiplam. The study enrolled 188 patients, with 128 receiving apitegromab and 60 receiving a placebo, administered every four weeks.

Results demonstrated that children aged 2 to 12 years treated with apitegromab experienced a significant improvement in motor function, measured by the Hammersmith Functional Motor Scale-Expanded (HFMSE), with a mean increase of 1.8 points from baseline over 12 months compared to placebo. The 20 mg/kg dosage showed a mean difference of 1.4 points, indicating a positive trend toward motor skill enhancement. Notably, the drug was well tolerated, with adverse events comparable to those seen in the placebo group, aligning with the typical safety profile for SMA therapies.

Dr. Thomas O. Crawford of Johns Hopkins Medicine and his colleagues concluded that apitegromab is effective in improving motor capabilities and is generally safe for patients with nonambulatory SMA. These findings support the potential use of muscle-targeting therapies to mitigate motor impairment in SMA patients. For more detailed information, refer to the full study in "The Lancet Neurology".

source: https://medicalxpress.com/news/2025-08-apitegromab-motor-function-spinal-muscular.html