A real-world study offers promising insights into the use of cladribine tablets (CladT) in patients with relapsing multiple sclerosis (PwRMS) who previously had suboptimal responses to injectable disease-modifying therapies (iDMTs). The phase 4 CLICK-MS study (NCT03933215), conducted over 24 months, evaluated effectiveness, adherence, satisfaction, and safety outcomes in this patient group.

CLICK-MS included 62 adult participants (mean age 49 years; 79% female) who transitioned from iDMTs—most commonly glatiramer acetate (56.5%) and interferon beta-1a (25.8%)—to CladT. At the end of the observation period, the annualized relapse rate (ARR) dropped from 0.2 to just 0.02, indicating a substantial reduction in relapses. Confidence intervals (95% CI, 0.000, 0.059) suggest strong consistency in this outcome.

Patient-reported outcomes also showed favorable results. Among respondents to the Multiple Sclerosis Treatment Adherence Questionnaire (MS-TAQ), adherence rates were exceptionally high (≥ 97.4%), and treatment satisfaction remained strong across the 2-year period, with average satisfaction scores exceeding 3.9 out of 5.

CladT demonstrated a manageable safety profile. Treatment-emergent adverse events (TEAEs) were reported by 41.9% of participants, with the majority being mild to moderate. The most frequently reported TEAEs were lymphopenia (14.5%), COVID-19 (6.5%), and herpes zoster (6.5%). Serious TEAEs occurred in 2 participants (3.2%). Grade 3 lymphopenia was observed in 1 patient, while no instances of grade 4 lymphopenia were reported.

Overall, 68% of patients completed the full CladT treatment course, while 32.3% discontinued, largely due to pandemic-related challenges.

The CLICK-MS findings reinforce the potential benefits of switching to CladT for PwRMS patients inadequately managed on iDMTs, highlighting its effectiveness, strong patient adherence, high satisfaction, and expected safety profile.

Reference

Katz J, Pace R, Miravalle A, Aldridge J, Chandler A. Real-world effectiveness and safety of cladribine tablets in patients with relapsing multiple sclerosis after suboptimal response to prior injectable therapy. Presented at: CMSC 2025; May 28-31; Phoenix, AZ.