PO134 Personalised dosing of cladribine to treat multiple sclerosis

Background Evidence suggests cladribine is an effective, safe and convenient disease modifying therapy (DMT) for people with multiple sclerosis (pwMS). Objective To report our clinical experience using cladribine in pwMS using a dosing scheme adapted to individual total lymphocyte count (TLC) thereby addressing a key safety concern raised in the rejection of oral cladribine by the European Medicines Agency in 2011. Methods Subcutaneous cladribine 10 mg/day was administered on up to seven days in five weeks to pwMS who had clinical and/or MRI disease activity. The number of injections was adjusted to individual TLC to avoid depletion below 0.5 × 10* 9/L (WHO Grade 3 or 4). Efficacy and safety were assessed. Results Forty-nine pwMS (31 women and 18 men, aged 44 years (SD=9 )) were followed up for a mean of 6 months after their first cladribine injection. Median EDSS at baseline was 5 (1–8, n=46). No serious treatment-related adverse event was observed, and neither any clinical disease activity. TLC dropped to between 0.5 and 1 × 10* 9/L while other white cells remained within normal range. Conclusion Cladribine was well tolerated and led to controlled TLC depletion leaving other cell lines largely unaffected. So far no new disease activity has been detected. Follow-up continues.