In patients with multiple sclerosis (MS), early initiation of high-efficacy disease-modifying therapies (heDMTs) has a beneficial impact on cognitive processing speed, which might prove especially valuable in newly diagnosed individuals with high white matter lesion load damage — known to be the subgroup of patients who are more prone to the development of cognitive dysfunction. These are the findings of a study published in the journal Multiple Sclerosis and Related Disorders.
The current study is an ongoing, prospective, longitudinal analysis conducted at the University Hospital “12 de Octubre” and the University Hospital “Ramón y Cajal,” both of which are located in Madrid, Spain.
Recognizing that the possible influence of timing of heDMTs on processing speed is sorely lacking in the current literature, the researchers sought to evaluate the extent to which early commencement of heDMTs is associated with improved evolution of processing speed, compared with either moderate-efficacy DMTs (meDMTs) or delayed initiation of heDMTs. A total of 695 patients with MS who had received an assessment of their processing speed at 12 months of follow-up, as measured with the iPad®-based Processing Speed Test (PST), were enrolled in the current study.
Overall, 210 of the 695 patients evaluated had received a prescription for a heDMT at some point and were classified in tertiles based on the proportion of their disease duration that they had been treated with this type of medication. According to the tertiles and time to receiving first heDMT from disease onset, patients were divided into the early heDMT group (n=97) or the delayed heDMT group (n=113).
Per multivariable analysis, each year of delay in initiating a DMT was associated with a significantly increased likelihood of cognitive worsening at 12 months (odds ratio [OR], 1.0323; 95% CI, 1.014-1.062; P <.05). Further, participants treated with meDMTs were at a significantly higher risk for cognitive worsening compared with participants treated with early heDMTs (OR, 2.57; 95% CI, 1.02-6.17).
Linear mixed model analysis of the between-group differences in adjusted mean change in PST Z-score from baseline showed the score to be significantly better in those with the longest percentage of their disease duration treated with heDMT (ie, the highest tertile), compared with those in the lowest tertile (difference of 0.37; 95% CI, 0.02-0.92; P =.036) and those in the medium tertile (difference, 0.39; 95% CI, 0.06-0.31; P =.037).
Study limitations included its observational, nonrandomized design without a propensity score approach. Additionally, since the longitudinal follow-up time of the study is short, the results merit confirmation in studies with longer follow-up periods.
The researchers concluded that “randomized trials are needed to delineate more accurately the rationale of this cognitive-based treatment approach” in patients with MS.
Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Labiano-FontcubertaA, Costa-Frossard L, Sainz de la Maza S, Rodríguez-JorgeF, Chico-GarcíaJL, MonrealE. The effect of timing of high-efficacy therapy on processing speed performance in multiple sclerosis. Mult Scler Relat Disord. Published online June 10, 2022. doi:10.1016/j.msard.2022.103959