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

Introduction: Cladribine is an effective immunomodulatory treatment used for relapsing forms of multiple sclerosis (MS).

Objectives: To 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.

Methods: We 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).

Results: Among 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.

Conclusions: In 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.