Cladribine tablets in highly-active relapsing multiple sclerosis real-world effectiveness in UK clinical practice (CAMELOT-MS)

<h3>Introduction</h3> Real-world evidence increasingly informs treatment choice in multiple sclerosis (MS). Cladribine tablets (CladT) received EU marketing authorisation in August 2017 in high-disease activity relapsing- remitting MS (HDA-RRMS) <h3>Objectives/Aims</h3> Understand effectiveness and safety of CladT in UK real-world setting up to 5 years after CladT initiation. <h3>Methods</h3> Phase 4 observational multi-centre study for patients who initiated CladT monotherapy for HDA- RRMS. <h3>Results</h3> 116 patients were enrolled, 40 (34.5%) were disease modifying therapies (DMT) naïve. Annualised relapse rate (ARR) during pre-treatment (-1–0 years) was 0.595 (95% CI: 0.470; 0.753). A declining ARR trend was observed after CladT initiation with an ARR of 0.101 (95% CI: 0.052; 0.194) during 0–1 years, 0.052 (95% CI: 0.023; 0.115) for 1–2 years and: 0.063 (95% CI: 0.024; 0.169) for 4–5 years. Relapse-free rate after CladT initiation was 0.75 (95% CI:0.58; 0.86) at 5 years. Only TEAEs of special interest were reported. Serious TEAE was reported in 1 (0.9%) patient; no TEAEs led to death. CladT-related TEAEs were lymphopenia (33/116, 28.4%), herpes zoster (4/116,3.4%), onychomycosis and oral herpes (1/116, 0.9% each). <h3>Conclusion</h3> Overall ARR showed a declining trend over 5 years after CladT initiation, together with a tolerable safety profile. <h3>Disclosure</h3> This study was sponsored by Merck (CrossRef Funder ID: 10.13039/100009945; NCT04997148). All authors disclosures available on request.