Effect of switching from daily injections of 20mg glatiramer acetate to 40mg three times a week on gray and white matter pathology in subjects with relapsing multiple sclerosis over 33 months (P2.398)

Objective: To investigate the effect of switching from daily injections of 20mg glatiramer acetate (GA) (20mg/daily) to GA 40mg three times a week (40mg × 3/weekly) on gray matter (GM) and white matter (WM) pathology, as measured by changes in diffusion-tensor imaging (DTI) in patients with relapsing multiple sclerosis (MS). Background: The effect of switching from GA 20mg/daily to GA 40mg 3/weekly on GM and WM pathology in MS patients is unknown. Design/Methods: This was an observational, single-blinded, cross-over, 33-months longitudinal, study that included 150 relapsing MS patients who were on treatment with GA 20mg/daily for 17 months (pre-index to index period), prior to switching to GA 40mg × 3/weekly because of convenience of application (index period), and then were followed for another 16 months while being on GA 40mg × 3/weekly (index to post-index period). DTI derived changes of mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA) were measured within patients between pre-index to index, index to post-index and pre-index to post-index period in the thalamus, normal appearing (NA) WM and NAGM. Results: No significant within-group differences were found in DTI measures between pre-index to index, index to post-index or pre-index to post-index period in the DTI analyses (p>0.05). 88% of the patients remained on treatment with GA 40mg × 3/weekly at post-index with low annualized relapse rate (0.2) and stable disability status (median Expanded Disability Status Scale score 3.0 at pre-index and 3.0 at post-index). No serious adverse events were detected over the follow-up. Conclusions: Over 33 months, relapsing MS patients treated with GA remained stable in their DTI GM and WM, and clinical outcomes. No differences in DTI GM and WM measures were detected after switching from GA 20m/daily to GA 40mg 3/weekly. Study Supported by: The study was funded by an investigator initiated grant from Teva Pharmaceuticals. Disclosure: Dr. Hagemeier has nothing to disclose. Dr. Weinstock-Guttman has received personal compensation for activities with Biogen, Teva Pharmaceuticals, EMD Serono, Genzyme&Sanofi, Novartis and Genentech as a speaker and consultant. Dr. Weinstock-Guttman has received research support from Biogen, Teva Pharmaceuticals, EMD Serono, Genzyme & Sanofi, Novartis, Genentech. Dr. Bergsland has nothing to disclose. Dr. Ramasamy has nothing to disclose. Dr. Durfee has nothing to disclose. Dr. Cherneva has nothing to disclose. Dr. Carl has nothing to disclose. Dr. Carl has nothing to disclose. Dr. Kolb has received personal compensation for activities with Teva, Acorda, Biogen, and Novartis. Dr. Hojnacki has received personal compensation for activities with Biogen Idec, Teva Neuorscience, Genzyme, Genentech, and EMD Serono as a speaker. Dr. Zivadinov has received personal compensation for activities with EMD Serono, Genzyme, Novartis, for speaking and consultant fees. Dr. Zivadinov has received personal compensation in an editorial capacity for BioMed Research International, BMC Medicine, BMC Neurology, Clinical CNS Drugs, Conf Pap Neurosci, Journal of Alzheimer9s Disease, Vein and Lymphatics, and Word J Surg Proc. Dr. Zivadinov has received research support from Biogen Idec, Claret Medical, Genzyme, Intekrin-Coherus, Novartis, and Teva Pharmaceuticals.