Substantial and comparable suppression of disease activity following early initiation of cladribine tablets, ocrelizumab or natalizumab as first pharmacologic treatment for relapsing multiple sclerosis: a real world study

Background We describe the efficacy and safety of recent high efficacy disease DMTs in DMT-naive patients with highly active RMS. Methods This was a retrospective, cross sectional study from the Kuwait national MS registry. Patients with RMS who received alemtuzumab, cladribine tablets or ocrelizumab as their first DMT for RMS, with ≥2 year of follow up were included. The primary endpoint was the change in relapse rate from treatment initiation to 1 year; changes in disability (Expanded Disability Status Scale [EDSS]), radiologic activity, the proportion with no evidence of disease activity-3 (NEDA-3), and the frequency of adverse events were secondary endpoints. Results Among 123 RRMS patients, 59 received ocrelizumab, 32 received cladribine tablets and 32 received alemtuzumab. About two-thirds (65%) were women. Substantial and similar (p>0.05) reductions occurred at the end of follow-up in annual relapse rate (by 93.2% for ocrelizumab, 87.5% for cladribine tablets, and 90.6% for alemtuzumab). The proportion with new T2 of gadolinium-enhancing MRI lesions across the three groups was reduced from 85–100% to 7–13%. Rates of confirmed disability progression were low (ocrelizumab 6.9%, cladribine tablets 3.1%, alemtuzumab 0%; p=0.280); disability was reduced in 15%, 22% and 38%, respectively. NEDA-3 was observed in 89.8%, 87.5%, and 84.4, respectively (p=0.784). No new or unexpected safety issues occurred. Conclusion Ocrelizumab, cladribine tablets and alemtuzumab reduced relapse rates and MRI activity, and prevented disease progression, when are initiated early in DMT-naive RMS patients. These data support the early use of high-efficacy DMTs for people with highly active RMS.