Cladribine treatment for highly active multiple sclerosis: Real-world clinical outcomes for years 3 and 4

Abstract

IntroductionCladribine is an effective immunomodulatory treatment used for relapsing forms of multiple sclerosis (MS). ObjectivesTo describe the clinical outcomes and rates of no evidence of disease activity (NEDA) in patients with highly-active disease treated with 2 years cumulative dose of cladribine, for years 3 and 4. MethodsWe used the Sheba Multiple Sclerosis computerized data registry to retrospectively evaluate year-3 and year-4 clinical outcomes and NEDA-2 rates in highly active RRMS patients who completed the 2-dose 2-year cladribine treatment protocol (3.5 mg/kg cumulative dose over 2 years). The first week of treatment in year 1 was considered as baseline. Data analyses were performed using Python (version 3.0) and SAS® (version 9.4 SAS Institute, Cary, NC). ResultsAmong 128 patients with highly-active MS that received cladribine treatment, 61 patients, 43 females, were studied for year-3 clinical outcomes, and 35 patients, 23 females, also for year-4. At the initiation of cladribine treatment, the mean ± SD age was 39.6 ± 10.74 years (45.9% of the patients were between 18 and 40 years), disease duration 12.7 ± 9.08 years, Expanded Disability Status Scale (EDSS) 3.7 ± 1.86 (54% had EDSS score > 3.0), and the annual relapse rate was 1.6 ± 0.9. The annual relapse rate decreased to 0.36 in year-3 and was 0.17 in year-4; 68.9% (42/61) of the patients were relapse-free in year-3, and 82.9% (29/35) were relapse-free in year-4. Disability at year-3 was 3.1 ± 2.07; 83.6% (51/61) of the patients remained neurologically stable (33, 54.1%) or improved (18, 29.5%). In year-4, EDSS was 3.2 ± 1.91, and 85.7% (30/35) of the patients remained stable (20, 57.1%) or improved (10, 28.6%). NEDA-2 was achieved for 59.0% (36/61) of patients in year-3, and for 74.3% (26/35) in year-4 of cladribine treatment. ConclusionsIn the real-world cladribine proved to be clinically effective in year-3 and year-4 of treatment in the majority of highly active RRMS patients.