Impact of Siponimod on Clinical and Radiological Parameters of Secondary Progressive Multiple Sclerosis: A Real-World Prospective Study.

Background and purpose: Secondary progressive multiple sclerosis (SPMS) presents with a challenging clinical phenotype, and siponimod has a potential to treat the active clinical phenotype of this disease. This single-center longitudinal study aimed to determine the therapeutic effects of siponimod in patients with active SPMS over 12 months.

Methods: The clinical and radiological parameters of 50 patients with active SPMS treated using siponimod were assessed at baseline and after a 1-year follow-up period using the annual relapse rate (ARR), the Expanded Disability Status Scale (EDSS), the occurrence of gadolinium-enhanced lesion (GdE+), the Modified Fatigue Impact Scale (MFIS), and the Symbol Digit Modalities Test. The urine bladder postvoid residual (PVR) volume was also measured in a subcohort of 39 participants. Participants with an EDSS score ≥5.0 at baseline were finally assessed separately in prespecified subgroup analyses.

Results: There were significant reductions in ARR (p<0.001), GdE+ (p<0.001), and MFIS score (p=0.001) during the follow-up period. The progression of physical and cognitive disabilities remained stable (p>0.05). The PVR-volume analysis revealed a significant decrease in urine bladder PVR volume (p<0.001). These observations were consistent for the subgroup with EDSS score ≥5.0.

Conclusions: Siponimod demonstrated efficacy in reducing ARR, GdE+, fatigue levels, and PVR volume, while maintaining stability in the cognitive and physical disability statuses of patients with SPMS. Similar findings were documented in the subgroup with EDSS score ≥5.0.