Preliminary Comparison of Baseline Cognition and Correlations with PROs of FTY Versus GA in MS Patients in a Longitudinal Observational Study

Background: Stable relapsing MS patients who are long-term users of FTY and GA have few if any signs of inflammation. However, their brain atrophy rates are unknown. Measures of brain atrophy, cognition, PROs and their interrelationships may provide insight into subclinical disease progression and whether it differs between disease modifying therapies.

Objectives: Compare baseline cognitive characteristics and describe correlations between Neuro-QoL scales and cognitive tests in a cohort of stable relapsing multiple sclerosis (MS) patients on fingolimod (FTY) or glatiramer acetate (GA) enrolled in a prospective 2-year study examining brain volume, cognition and patient reported outcomes (PROs).

Methods: Relapsing MS patients aged 18-60 years on FTY or GA for >2 years were identified and will be followed for 2 years with a baseline and subsequent annual visits including MRI, cognitive testing, and the NeuroQoL. In this analysis, baseline performance was compared on measures of attention/processing speed, executive function, and memory on the following tests: Paced Auditory Serial Addition Test (PASAT), Symbol Digital Modalities Test (SDMT), Verbal Fluency (VF), California Verbal Learning Test-II (CVLT-II), Brief Visuospatial Memory Test-Revised (BVMT-R). An analysis of baseline cognitive characteristics by treatment arm, and correlations between Neuro-QoL scales and cognitive tests for all currently enrolled patients is presented.

Results: For this analysis, 45/60 planned FTY and 25/60 planned GA patients had completed a baseline visit. No group differences were found for demographic or disease characteristics (disease duration, EDSS, or normalized brain volume). Similarly, no group differences were found on the cognitive measures (all p>0.05). For all patients, PASAT, SDMT, and VF correlated with NeuroQoL general cognition and executive function scales (all p<0.05). Correlations between CVLT-II and BVMT-R and the NeuroQoL general cognition scale approached significance (p=0.06). The NeuroQoL fatigue scale was negatively correlated with VF (p=0.01).

Conclusions: Preliminary analysis suggests that stable long-term users of FTY and GA are comparable on measures of cognition. Performance on all objective cognitive measures was correlated with subjective self-report of cognitive concerns. This comparison will help determine whether future differences over the 2 year study period can be attributed to type of therapy or other group differences.