Importance  With multiple and increasingly effective therapies for relapsing forms of multiple sclerosis (MS), disease-free status or no evidence of disease activity (NEDA) has become a treatment goal and a new outcome measure. However, the persistence of NEDA over time and its predictive power for long-term prognosis are unknown.
Objective  To investigate NEDA during 7 years as measured by relapses, disability progression, and yearly magnetic resonance imaging (MRI).
Design, Setting, and Participants  Patients were selected from the 2200-patient Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB) cohort study. Patients were required to have an initial diagnosis of clinically isolated syndrome or relapsing-remitting MS and a minimum of 7 years of prospective follow-up that included yearly brain MRI and biannual clinical visits (n = 219). Patients were analyzed independent of disease-modifying therapy. Patients were classified as having early (recent-onset) MS if they were 5 years or less from their first MS symptom at enrollment or otherwise considered to have established MS (>5 years from onset).
Main Outcomes and Measures  NEDA was defined as a composite that consisted of absence of relapses, no sustained Expanded Disability Status Scale score progression, and no new or enlarging T2 or T1 gadolinium-enhancing lesions on annual MRI. Relapses, progression, and MRI changes were also investigated as individual outcomes.
Results  A total of 99 of 215 patients (46.0%) had NEDA for clinical and MRI measures at 1 year, but only 17 of 216 (7.9%) maintained NEDA status after 7 years. No differences were found in NEDA status between patients with early vs established MS. A dissociation was found between clinical and MRI disease activity. Each year, 30.6% (64 of 209) to 42.9% (93 of 217) of the cohort had evidence of either clinical or MRI disease activity but not both. NEDA at 2 years had a positive predictive value of 78.3% for no progression (Expanded Disability Status Scale score change ≤0.5) at 7 years. Only minor improvement was found in the positive predictive values with additional follow-up of 1 to 3 years.
Conclusions and Relevance  NEDA is difficult to sustain long term even with treatment. NEDA status at 2 years may be optimal in terms of prognostic value in the longer term. Our results provide a basis for investigating NEDA as an outcome measure and treatment goal and for evaluating the effect of new MS drugs on NEDA.

See other data on this, by clicking here and using the tabs found near to the top of the page