Oral Cladribine Promotes Remyelination in Some Patients With Multiple Sclerosis

Oral cladribine increases the odds of remyelination in some patients with multiple sclerosis (MS), according to study results presented at the 40th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), held in Copenhagen, Denmark, from September 18 to 20, 2024.

Previous studies have shown that oral cladribine may be beneficial in myelin repair in MS. Therefore, in an open-label study, researchers assessed remyelination of MS lesions following treatment with oral cladribine, as well as the effect of controlled inflammatory activity on remyelination capacity.

The researchers collected data on myelin content and changes in lesions at baseline and during treatment with oral cladribine. All participants underwent a brain magnetic resonance imaging (MRI), clinical evaluations, and peripheral lymphocyte immunophenotyping.

No Evidence of Disease Activity-3 (NEDA-3) was defined as lack of relapses, MRI activity, and disability progression. A q-Space myelin map was used to classify lesions as remyelinating or demyelinating.

A total of 10 patients (median age, 24.1) with highly active relapsing-remitting MS (RRMS) were included in the analysis. Patients had an average disease duration of 13.8 months and Expanded Disability Status Scale (EDSS) score of 2.5, with 2 relapses in the previous year. Lesion load was 77 at baseline.

Of a total of 812 MS lesions, 156 (19.2%) were observed to have remyelinated during the 2-year study period.

Using the q-Space myelin map, the researchers noted that the proportions of remyelinating and demyelinating lesions were inversely correlated (r, -0.729; P =.017).

Among those who achieved NEDA-3 at the start of treatment vs other participants, 220 (27.1%) vs 98 (12.0%) lesions, respectively, were remyelinated (P <.001). Based on these findings, NEDA-3 was noted to be the strongest clinical variable predictive of remyelination (P =.007). Other predictors of remyelination included lesion location, contrast enhancement, and myelin content at baseline (P <.020). Higher frequencies of regulatory T cells until 1 year were also found to predict remyelination (P <.010).

“In patients treated with oral cladribine, achieving NEDA-3 from the start of therapy, and presenting a higher proportion of regulatory T cells during the first year increase the odds of remyelination,” the researchers concluded.