Disability Progression in Multiple Sclerosis Patients Treated with Natalizumab in the Long-term STRATA Study (P3.163)

OBJECTIVE:To assess rates of disease progression in patients with relapsing-remitting multiple sclerosis (MS) on long-term natalizumab therapy. BACKGROUND:The Safety of TYSABRI ® Re-dosing and Treatment (STRATA) study is a single-arm, open-label, multinational study of natalizumab treatment in patients with relapsing MS who completed the randomized AFFIRM, SENTINEL, and GLANCE trials and their open-label extensions (the “feeder studies”). DESIGN/METHODS:Analyses included patients with 蠅2 postbaseline Expanded Disability Status Scale (EDSS) assessments. The proportions of patients with confirmed progression to an EDSS score of 蠅4.0 or 蠅6.0, sustained for at least 6 months, were evaluated. Patients who had already reached the milestone at STRATA baseline were excluded. Proportions were estimated using the Kaplan-Meier (KM) method. RESULTS:Of the 1094 patients enrolled in STRATA, 300 had an EDSS score 蠅4.0 (32% of patients originally randomized to placebo and 25% of those originally randomized to natalizumab) and 109 had an EDSS score 蠅6.0 (13% of patients originally randomized to placebo and 8% of those originally randomized to natalizumab) at STRATA baseline. Excluding the 300 patients with an EDSS score 蠅4.0 at STRATA baseline, 56 of 617 patients with 蠅2 postbaseline assessments reached a confirmed EDSS score 蠅4.0 by the 6-year time point in STRATA (estimated KM proportion, 12%). Similarly, of 770 assessed, 37 reached a confirmed EDSS score 蠅6.0 (estimated KM proportion, 6%). Sensitivity analyses will also be presented. The adverse event profile of natalizumab remained unchanged. CONCLUSIONS:With long-term natalizumab treatment in STRATA, rates of disease progression were low. The majority of patients with an EDSS score 蠅4.0 or 蠅6.0 at the 6-year time point in STRATA had reached this score prior to enrollment in STRATA. The safety profile of natalizumab treatment in STRATA is consistent with postmarketing experience. Study Supported by:Biogen Idec Inc. Disclosure: Dr. Goodman has received personal compensation for activities with Acorda Therapeutics, Biogen Idec, Genzyme-Sanofi, GW, Mylan, Novartis, and Teva Neuroscience as a consultant. Dr. Goodman has received research support from Acorda Therapeutics, Avanir, Biogen Idec, EMD Serono, Genzyme-Sanofi, Novartis, Ono, Roche, Sun, Takeda, and Teva Neuroscience. Dr. Kappos has received personal compensation for activities with the University Hospital Basel. Dr. Kappos has received research support from the Swiss MS Society, Swiss National Research Foundation, the European Union, Gianni Rubatto Foundation, Novartis, and Roche Diagnostics Corp. Dr. Lublin has received personal compensation for activities with Biogen Idec, EMD Serono, Inc., Novartis, Teva Neuroscience, Actelion, Sanofi-Aventis Pharmaceuticals, Inc., Acorda Therapeutis, Questcor, Roche, Genentech, Inc., Celgene, Johnson & Johnson, Revalesio, Coronado Bioscience, Genzyme Corporation, MedImmune, Bristol-Myers Squibb Company, Xenoport, Receptos, Forward Pharma, and Osmotica. Dr. Lublin has received personal compensation in an editorial capacity for Multiple Sclerosis and Related Diseases. Dr. Lublin has received research support from Acorda Therapeutics, Inc., Biogen Idec, Novartis, Teva Neuroscience, Genzyme Corporation, Sanofi-Aventis Pharmaceuticals, Inc., Celgene, National Institutes of Health, and the National Multiple Sclerosis Society. Dr. Belachew has received personal compensation for activities with Biogen Idec as an employee. Dr. Belachew holds stock and/or stock options in Biogen Idec, which sponsored research in which Dr. Belachew was involved as an investigator. Dr. Chirieac has received personal compensation for activities with Biogen Idec as an employee. Dr. Forrestal has received personal compensation for activities with Biogen Idec as an employee. Dr. Duda has received personal compensation for activities with Biogen Idec as an employee.