Multicentre Observational Study of Treatment Satisfaction with Cladribine Tablets in the Management of Relapsing Multiple Sclerosis in the Arabian Gulf: The CLUE Study

Introduction: Inconvenient administration and side effects of some disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) can deter adherence. We evaluated treatment satisfaction with cladribine tablets (CladT) for RMS in the Arabian Gulf. Methods: This was a non-interventional, multicentre, prospective observational study in non-pregnant/lactating adults (aged ≥ 18 years) with RMS eligible for 1st treatment with CladT (EU labelling). The primary outcome was overall treatment satisfaction at 6 months (Treatment Satisfaction Questionnaire for Medication [TSQM]-14, v. 1.4), Global Satisfaction subscale. Secondary endpoints were TSQM-14 scores for convenience, satisfaction with side effects and satisfaction with effectiveness. Patients provided written informed consent. Results: Of 63 patients screened, 58 received CladT and 55 completed the study. Mean age was 33 ± 9 years; mean weight 73 ± 17 kg; 31% male/69% female; mostly from the United Arab Emirates (52%) or Kuwait (30%). All had RMS (mean 0.9 ± 1.1 relapses in the past year), mean Expanded Disability Status Scale (EDSS) 1.4 ± 1.2; 36% were DMT-naïve. Mean [95% CI] score was high for overall treatment satisfaction (77.8 [73.0–82.6]), ease of use (87.4 [83.7–91.0]), tolerability (94.2 [91.0–97.3]) and effectiveness (76.2 [71.6–80.7]). Scores were similar irrespective of DMT history, age, gender, relapse history or EDSS. No relapses or serious treatment-emergent adverse events (TEAE) occurred. Two severe TEAE occurred (fatigue, headache) and 16% reported lymphopenia (two cases of grade 3 lymphopenia). Absolute lymphocyte counts at baseline and 6 months were 2.2 ± 0.8 × 109/L and 1.3 ± 0.3 × 109/L, respectively. Conclusions: Treatment satisfaction, ease of use, tolerability and patient-perceived effectiveness for CladT were high, irrespective of baseline demographics, disease characteristics and prior treatment.