ABSTRACT
Introduction: As a high-efficacy multiple sclerosis (MS) treatment, cladribine necessitates empirical data from diverse populations. Objective(s): To study the efficacy and safety data of cladribine treatment in a real-world setting. Method(s): Patients from eight MS clinics in Turkey were involved in the study. We retrieved the demographic, clinical, MRI, safety, laboratory, COVID-19, and pregnancy records of patients with at least six months of follow-up on cladribine treatment. Result(s): Our study included 210 MS patients (52 males, 158 females;193 relapsing and 17 relapsing-progressive MS). The mean age at MS disease onset was 27.6 years (+/-8.5). Before cladribine treatment, 56.7% of patients used first-line, and 41.9% used both first and second-line therapies. During a mean follow-up period of 13.0 months (+/-4.7) following cladribine treatment, 5.7% of patients experienced a relapse. The shortest duration of relapse following cladribine administration was one week, and the longest duration was 15.3 months. Interestingly, 50% of the relapses occurred within the first three months. Among relapsing patients, five switched from fingolimod, two from dimethylfumarate, and one from ocrelizumab and interferon-beta. The mean annualized relapse rate was 0.41 (+/-0.41) in the two years preceding cladribine and 0.11 (+/-0.55) one year following treatment. At baseline, the mean EDSS score was 2.47 (+/-1.63), and 51.9% of patients ranked below EDSS 3. EDSS progression was observed in 7.6% of patients following cladribine treatment. On cladribine, eight patients (9.4%) exhibited radiological progression. There was no difference in NEDA status between patients switching from first or second-line therapy (p=0.43). COVID was observed in 73 patients, 54 of them had a mild disease course, six had a moderate disease course, and one had a severe disease course. There have been no COVID-related fatalities. There were five pregnancies documented, three of which are currently ongoing. One of the pregnancies ended with healthy childbirth, while the other was terminated in the first trimester with a miscarriage. Conclusion(s): Despite the relatively short duration of follow-up, our study demonstrates that cladribine is effective in providing NEDA. Moreover, switching from fingolimod to cladribine may increase the likelihood of early relapse.