Long-term Real-world Safety and Efficacy of Cladribine Tablets in Patients with Relapsing-Remitting Multiple...

Although oral cladribine received approval for treating relapsing-remitting multiple sclerosis (RRMS), real-world evidence regarding its long-term effectiveness and safety in the United Arab Emirates (UAE) remains limited.

To evaluate efficacy and safety outcomes of RRMS patients treated with cladribine tablets (CladT) and identify early predictors of response.

This is a multicenter, observational, retrospective study of RRMS patients treated with CladT from four tertiary MS centers in the UAE. Relapses, disability worsening, occurrence of new or enlarging T2-hyperintense magnetic resonance imaging (MRI) lesions and the proportion of patients achieving no-evidence-of-disease-activity-3 (NEDA-3) status were assessed. Safety outcomes included lymphocyte counts, infections and malignancy. The association between baseline characteristics and outcomes was tested to identify potential predictors of response.

A total of 163 MS patients were included, 120 (73.6%) of whom were females. Patients were treated with CladT, with a median (IQR) follow-up of 2.0 (1.0-2.6) years. A total of 121 (74.2%) patients had received another disease-modifying therapy (DMT) before cladribine. By the end of follow-up, the mean annualized relapse rate decreased by 84.4% (p<0.001). Most patients (91.8%) showed no disability progression, 74.1% had no new MRI activity, and 70.5% achieved NEDA-3. The number of relapses prior to CladT was the only predictor of NEDA-3. Safety outcomes included 7 adverse events (2.5%), with no hospitalizations. One patient developed a malignancy (astrocytoma) 1.2 years after treatment initiation.

Our study results confirm the safety and efficacy profiles of CladT reported in Phase 3 clinical trials and other real-world studies.