Long-term follow-up of patients with a first clinical demyelinating event (clinically isolated syndrome) who received cladribine tablets in CLASSIC-MS: Findings for the ORACLE-MS cohort

Background: CLASSIC-MS explored long-term outcomes of patients treated with cladribine tablets. Objective: Assess long-term efficacy in patients previously enrolled in ORACLE-MS, a Phase III parent trial. Methods: ORACLE-MS included patients with a first clinical demyelinating event (FCDE or clinically isolated syndrome) who received ⩾1 course of cladribine tablets or placebo. With a median follow-up time of 9.5 years, CLASSIC-MS assessed conversion rates to clinically definite multiple sclerosis (CDMS), time-to-conversion, relapse rates, long-term mobility/disability status and subsequent disease-modifying therapy (DMT) use. Results: Of 227 patients from the ORACLE-MS cohort of 616, 68.7% were exposed to cladribine tablets and 31.3% were never exposed. Of the exposed patients at risk, 51.5% converted to CDMS with a median conversion time of 8.4 (95% confidence interval (CI): 5.4–not estimable) years, versus 80.6%, median time 0.8 (95% CI: 0.3–2.4) years, for never exposed. Exposed patients were less likely to be using a wheelchair or ambulatory device or receive subsequent DMTs, and 53.2% were relapse-free versus 28.2% never exposed. Conclusions: Proportionally, more FCDE patients exposed to cladribine tablets experienced delayed conversion to CDMS and fewer relapses and were less likely to use a wheelchair or ambulatory device than never-exposed patients, at 9.5 years (median).