Subgroup analysis of clinical and MRI outcomes in participants with a first clinical demyelinating event at risk of multiple sclerosis in the ORACLE-MS study

•Cladribine tablets reduce the risk of conversion to multiple sclerosis•Cladribine tablets reduce multiple sclerosis lesion burden on MRI•Age, number of MRI lesions, and multifocal onset are linked to MS disease recurrence•Benefits of cladribine tablets are observed in subgroups by disease characteristics•Benefits of cladribine tablets are observed in subgroups by age and sex In the Phase 3, 96-week ORACLE-MS study, cladribine 10 mg tablets (3.5 mg/kg or 5.25 mg/kg cumulative dose over 2 years) significantly reduced the rate of conversion to clinically definite multiple sclerosis (CDMS) per the Poser criteria (henceforth referred to as CDMS), multiple sclerosis (MS) per the 2005 McDonald criteria, and the number of new or persisting T1 gadolinium-enhancing (Gd+), new or enlarging T2, and combined unique active (CUA) lesions versus placebo in participants with a first clinical demyelinating event (FCDE). Patient demographic and disease characteristics may be predictors of disease progression. The current study analyzed the effect of cladribine tablets in subgroups of participants in the ORACLE-MS study by baseline demographics and disease characteristics. This analysis retrospectively examined data collected from 616 participants enrolled in the ORACLE-MS study (placebo, n=206; cladribine tablets 3.5 mg/kg, n=206; cladribine tablets 5.25 mg/kg, n=204). Five subgroups were predetermined by baseline demographics, including sex, age (