To study change of disability  in patients with highly-active relapsing remitting multiple sclerosis (RRMS) treated with cladribine or ocrelizumab.

Highly active MS patients have a higher risk of early progression.

This is prospective study including RRMS who were treated with cladribine or ocrelizumab and have one year follow up. Expanded disability status scale (EDSS) at initiation of treatment and at the end of observational period were reported. Confirmed disability progression (CDP) on EDSS defined as increase on the EDSS of at least 1.5 points for baseline EDSS of 0, an increase on the EDSS of at least 1 point for baseline EDSS between 1 and 5, or an increase of at least 0.5 point for a baseline EDSS at least 5.5. Improved disability was defined as any decrease in EDSS score 1 or more if baseline EDSS was 1–4.5 or 0.5 or more if EDSS was 5.0 or more.

Among 200 patients with highly-active MS, 72 patients received cladribine tablets and 128 received ocrelizumab infusions. Most of this cohort are females 139 (69.5%) with mean age 34.62 ±9.80 and mean disease duration 7.30 ±5.97. EDSS was stable among most of patients who received cladribine 56 (77.8%) and those who received ocrelizumab 105 (82%); P<0.466.CPD was similar among patients under cladribine 5(6.9%) and those under ocrelizumab 9 (7%) ; P<0.983. Improvement of disability was higher among cladribine group 11 (15.3%) compared to ocrelizumab group 14 (10.9%); P<0.466. The mean EDSS score before cladribine was 1.63±1.30, whereas the mean EDSS before Ocrevus was 1.80±1.31. EDSS score remained stable under both cladribine 1.56±1.40 and under ocrelizumab1.78±1.24. Patients reported mild adverse events in similar ratios under both cladribine and ocrelizumab (19.4%, 18% respectively, p>0.850).

Both cladribine and ocrelizumab resulted similar in terms of EDSS stability and safety profile.