Dalfampridine is an effective treatment option for improving information processing in multiple sclerosis (MS), according to a study published in Neurology.

This double-blind, randomized, placebo-controlled trial included 120 participants (74 women, 46 men, mean age 48). The participants were randomly assigned with a 2:1 ratio to receive either dalfampridine 10 mg or placebo twice daily for 12 weeks. Patients with MS below the 10th percentile of the reference value on the Symbol Digit Modalities Test (SDMT) were included in the trial. For the purposes of determining efficacy, participants underwent a comprehensive neuropsychological evaluation at the time of screening, at the end of the 12-week treatment, and after a 4-week follow-up.

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The primary end point of the study was improvement in SDMT score. Investigators reported that the dalfampridine group showed an increase of SDMT scores vs placebo group (mean change 9.9 [95% CI, 8.5-11.4] vs mean change 5.2 [95% CI, 2.8-7.6]; P =.0018). This trend, however, was not maintained in the 4-week follow-up. A greater proportion of patients were reported to have an improvement in SDMT score of least 20% in the treated (86.1%) vs the placebo (60.3%) group.

Secondary end points were considered to be an improvement in other cognitive tests of the Rao Brief Repeatable Battery of Neuropsychological Tests. Data showed dalfampridine had a positive effect on information processing speed and working memory and found a beneficial effect of the drug in Paced Auditory Serial Addition Test.

Tertiary outcomes such as the 25 feet walking test and Modified Fatigue Impact Scale was considered to evaluate the effect of fatigue in terms of physical, cognitive, and psychosocial functioning. Investigators found no improvement in the lower limb function and statistically insignificant improvement in the 25 feet walking test for the treated group. However, dalfampridine was reported to have a positive effect on fatigue and a significant benefit on cognitive subscale.

Short study duration (12 weeks) and moderate sample size may have limited the findings of this study. Regarding insignificant findings of the 25 feet walking test, investigators believe the “lack of statistical significance is probably due to the study design, which was powered to detect cognitive changes rather than motor improvement.”

The investigators concluded that this study provides Class I evidence in demonstrating the “effectiveness of dalfampridine in improving [information processing speed] in patients with MS with impairment in the SDMT and confirms that the safety profile of the drug is in line with published data.”

Disclosure: This clinical trial was supported by Biogen. Please see the original reference for a full list of authors’ disclosures.

Reference

De Giglio L, De Luca F, Gurreri F, et al. Effect of dalfampridine on information processing speed impairment in multiple sclerosis [published online July 22, 2019]. Neurology. doi: 10.1212/WNL.0000000000007970