Cladribine tablets in people with relapsing multiple sclerosis: A real-world multicentric study from southeast European MS centers.

Background: Cladribine is an oral disease-modifying drug authorized by the European Medicine Agency for the treatment of highly active relapsing multiple sclerosis (MS).

Objectives: To provide real-world evidence of cladribine's effectiveness and safety in people with MS (pwMS).

Methods: A retrospective observational multi-center, multi-national study of pwMS who were started on cladribine tablets in ten centers from five European countries.

Results: We identified 320 pwMS treated with cladribine tablets. The most common comorbidities were arterial hypertension and depression. Three patients had resolved hepatitis B infection, while eight had positive Quantiferon test prior to cladribine commencement. There were six pwMS who had malignant diseases, but all were non-active. During year 1, 91.6% pwMS did not have EDSS worsening, 86.9% were relapse-free and 72.9% did not have MRI activity. During the second year, 90.2% did not experience EDSS worsening, 86.5% were relapse-free and 75.5% did not have MRI activity. NEDA-3 was present in 58.0% pwMS in year 1 and in 54.2% in year 2. In a multivariable logistic regression model age positively predicted NEDA-3 in year 1. The most common adverse events were infections and skin-related adverse events. Lymphopenia was noted in 54.7% of pwMS at month 2 and in 35.0% at month 6. Two pwMS had a newly discovered malignant disease, one breast cancer, and one melanoma, during the first year of treatment.

Conclusion: Our real-world data on the effectiveness and safety of cladribine tablets are comparable to the pivotal study and other real-world data with no new safety signals.