#AANAM – Mavenclad, for RRMS, Lowers Long-term Need for Other DMTs

Editor’s note: The Multiple Sclerosis News Today team is providing in-depth coverage of the 2021 Virtual AAN Annual Meeting, April 17–22. Go here to read the latest stories from the conference.

A majority of the relapsing-remitting multiple sclerosis (RRMS) patients given Mavenclad (cladribine) tablets in the CLARITY Phase 3 trial did not need further disease-modifying therapy (DMT) for at least four years after their last trial dose, a recent analysis found.

This held even with more than half of the patients (58.1%) experiencing multiple sclerosis (MS) reactivation in that period of time.

These findings are from the ongoing CLASSIC-MS Phase 4 trial (NCT03961204), which is evaluating the long-term outcomes of Mavenclad use among people who previously participated in the CLARITY study (NCT00213135), with or without then enrolling in the CLARITY extension trial (NCT00641537).

Gavin Giovannoni, PhD, a professor of neurology at Barts and The London School of Medicine and Dentistry, presented the results on behalf of the CLASSIC-MS Steering Committee at the recent American Academy of Neurology meeting.

His poster was titled, “CLASSIC-MS: Long-term Efficacy and Real-World Treatment Patterns for Patients with Relapsing Multiple Sclerosis who Received Cladribine Tablets in Phase III Parent Trials.”

Mavenclad, developed by EMD Serono (Merck KGaA outside of the U.S. and Canada), is approved for treating active and relapsing forms of MS. It works by reducing the number of the circulating immune cells that drive inflammation and nerve degeneration in MS patients.

The CLARITY trial showed that a 3.5 mg/kg dose of Mavenclad significantly reduced the risk of disease progression at six months by 47%, with effects being even more pronounced in a subgroup with high relapse activity plus disease activity (an 82% reduction).

These benefits were sustained for long periods, with nearly half of the extension study patients who were randomized to switch from Mavenclad to a placebo achieving no evidence of disease activity (NEDA-3) in that study’s third and fourth year.

CLASSIC-MS was designed to investigate long-term outcomes in RRMS patients who participated in CLARITY, regardless of whether they also took part in the extension trial. A total of 93 people enrolled, including 79 who participated in the CLARITY extension; of these people, 61% were women, and their mean age was 57.

At the time of entry into CLASSIC-MS, patients had received their last dose in either of the CLARITY trials a median of 10.4 years earlier, and had experienced minimal disease progression — an increase in Expanded Disability Status Scale (EDSS) scores from 3.05 at the time of CLARITY entry to 4.06. Nearly all (93.5%) had taken Mavenclad in those trials.

Researchers looked for long-term responders based on two distinct definitions. The first covered 82.8% of these patients, and was defined as not needing a further DMT until at least four years after their last Mavenclad dose. The second definition applied to long-term responders with no evidence of MS reactivation for four years after that same last dose — covering 36.6% of these patients.

Of note, about 19.4% of patients met both definitions, meaning they had no evidence of MS reactivation and required no additional DMT treatment.

Among those given further treatment, 21.5% received one DMT, 7.5% two DMTs, and 2.2% used three. Most of those taking further DMTs (75.9%) first received them via injection. Other treatments included antibody and investigational therapies.

“In conclusion, our interim data from a small sample of CLASSIC-MS … suggests sustained efficacy of [Mavenclad] tablets,” Giovannoni said.

“Over the median 10.4 years of follow-up since the last dose in the parent study there was minimal increase in disability [and] the majority [of patients] did not receive further disease modifying therapy for at least four years after the last dose in the parent study,” he concluded.

In another poster, “Treatment Satisfaction in Patients with Highly-active Relapsing Multiple Sclerosis Treated with Cladribine Tablets: CLARIFY-MS Study Interim Analysis,” researchers presented interim data from another real-world Phase 4 trial, demonstrating that patients are generally satisfied with Mavenclad tablet treatment after six months, and experience few serious side effects.

The CLARIFY-MS trial (NCT03369665) is investigating changes in quality of live among people with highly active and relapsing MS given Mavenclad for a period of two years. A total of 482 people have been enrolled.

“Patients were highly satisfied with convenience and side effect profile of [Mavenclad] tablets and, at six months, patients were generally satisfied with the treatment. There were few adverse events in the first six months of the study,” said Bruno Brochet, a professor at the University of Bordeaux, in France, who presented the findings.