Merck has announced results from a five-year multiple sclerosis (MS) real-world data study, in which 75% of patients showed no disability progression at five years post treatment with Mavenclad (cladribine tablets).

The data further characterise the long-term efficacy and safety profile of the drug based on patients treated in CLARITY and then placebo in CLARITY Extension, with at least one post-baseline Expanded Disability Status Scale (EDSS) measurement.

Results were presented from a retrospective analysis of real-world follow-up data from an Italian MS registry, consisting of patients with clinically isolated syndrome or relapsing forms of MS who received at least one course of Mavenclad in the original clinical trial programme.

At five years after receiving the last dose of the treatment, nearly two-thirds of patients (64%) had no disability progression and more than half of the patients (57%) were free of relapse.

Professor Gavin Giovannoni, a lead investigator in the CLARITY studies, said the findings show "that Mavenclad continues to display sustained efficacy in a majority of patients at five years after starting treatment and that these results are consistent with data we are seeing from real-world experience.”

He continued, “As a neurologist, this is important for me to see, as it shows that findings from the clinical development programme of Mavenclad will be borne out in clinical practice.”

The drug is a short-course oral therapy that selectively and periodically targets lymphocytes thought to be integral to the pathological process of relapsing MS, and was granted marketing authorisation by the European Commission 2017. Since then it has been approved in 69 countries, including Canada, Australia and the US.