Sex differences in outcomes of disease-modifying treatments for multiple sclerosis: A systematic review

Background: Multiple sclerosis (MS) is a chronic immune mediated demyelinating disease of the central nervous system that exhibits sexual dimorphism and may benefit from sex-specific treatment. To investigate a potential influence of sex on immunomodulatory therapeutic effects in patients with MS, we performed a comprehensive analysis of published studies examining sex differences in the effects of disease-modifying treatments (DMTs) for MS. Methods: PubMed, Cochrane Library, and Web of Science databases were searched for clinical studies involving patients with MS who were undergoing DMTs. Studies were included if they investigated sex differences in DMT outcomes. Results: Fourteen studies with 11,425 participants were included; 11 of these studies were randomized controlled trials, and 3 were cohort studies. Although the studies did occasionally show sex-specific differences for some clinical outcomes in patients with MS who received DMTs, the limitation of subgroup analysis design made it difficult to draw conclusions on the direction or the extent of the sex-based effect. Conclusion: No clear sex-based differences in response to DMTs have been documented to date. More studies will be needed to better elucidate the presence of sex differences on the DMT effects.