Early Intensive Versus Escalation Approach: Ten-Year Impact on Disability in Relapsing Multiple Sclerosis

Objective: To evaluate the long-term impact of early intensive treatment (EIT) versus escalation (ESC) strategies using high-efficacy disease-modifying therapies (HE-DMTs) on disability progression in relapsing multiple sclerosis (RMS). Methods: This observational study included 4878 RMS patients from the Italian Multiple Sclerosis Register. Eligible participants initiated their first disease-modifying therapy (DMT) within 3 years of disease onset and had ≥ 5 years of follow-up with at least three Expanded Disability Status Scale (EDSS) evaluations. Patients were categorized into the EIT group if they started with HE-DMTs and into the ESC group if HE-DMTs were initiated after ≥ 1 year of moderate-efficacy therapy. Propensity score matching was performed to balance baseline characteristics. Outcomes included disability trajectories assessed using linear mixed models for repeated measures and risks of confirmed disability accrual (CDA), progression independent of relapse activity (PIRA), and relapse-associated worsening (RAW) evaluated using Cox proportional hazards models. Results: Post-matching analysis of 908 pairs revealed significantly slower disability progression in the EIT group compared to the ESC group. At 10 years, the delta-EDSS difference between groups was -0.63 (95% CI: -0.83 to -0.43; p < 0.0001). ESC was associated with higher risks of CDA (HR 1.36, 95% CI: 1.20-1.54; p < 0.0001), PIRA (HR 1.22, 95% CI: 1.05-1.40; p = 0.0074), and RAW (HR 1.55, 95% CI: 1.17-2.05; p = 0.0021). Interpretation: EIT significantly reduces long-term disability progression in RMS compared to ESC. These findings underscore the potential of EIT to optimize long-term outcomes in RMS patients.