CG20
Cognitive Evolution in Tysabri (natalizumab) Treated Multiple Sclerosis Patients
Cognitive dysfunction affects 40-60% of MS patients and progresses over time.
Natalizumab has shown to be superior to placebo in preserving cognitive function for the first two
years of therapy.
Objectives:
The objectives are to understand the impact of natalizumab on cognition beyond
two years of therapy and investigate whether baseline characteristics are predictive of clinical
response.
Methods:
This is a single-center, 24-month, observational study. Sixty-three patients treated with
natalizumab were assessed prior to monthly infusions using the Cogstate battery and SDMT. The
Beck depression questionnaire was also administered at baseline and every 4th month prior to
infusion. Patient demographics, MS treatment history, EDSS, MSSS, and natalizumab treatment
duration were collected at baseline. Patients with cognitive impairment from other causes were
excluded. A linear mixed model was conducted with time on natalizumab (4 years, n=12) as a
between-subjects factor, time point as a within-subjects factor, and age, EDSS, type of MS and
number of prior drug treatments as covariates. The current data are from the 12-month interim
analysis.
Results:
Irrespective of time on natalizumab, significant improvements were observed in executive
function (p< .0001), verbal memory (p< .0001), and working memory (p< .0001), whereas
processing speed (p=.19) and attention (p=.15) remained unchanged. Only one patient had clinically
meaningful decline, defined as a decline of 1 or more standard deviations over three consecutive
months on two or more Cogstate tests.
Conclusions:
Interim analysis suggests that natalizumab can preserve cognitive function and the
ability to learn beyond two years of continuous therapy.