Natalizumab in Anti-JC Virus Seronegative Patients with Early Relapsing-Remitting Multiple Sclerosis: Interim Results from the STRIVE Study

Background: Earlier use of highly effective multiple sclerosis (MS) therapies has been shown to significantly improve clinical outcomes.

Objectives: STRIVE was designed to determine the proportion of anti-JC virus antibody-negative patients with relapsing-remitting multiple sclerosis initiating natalizumab early in their disease course who demonstrated no evidence of disease activity (NEDA), defined as no Expanded Disability Status Scale (EDSS) progression, no relapses, no Gd+ lesions, and no new or enlarging T2-hyperintense lesions, at months 12 and 24.

Methods: STRIVE is a multicenter, observational, open-label, single-arm study. Continuous variables were analyzed with summary statistics. Categorical variables were analyzed with frequency distributions. P-values and odds ratios were obtained from logistic regression models adjusting for baseline EDSS score (≤2 vs >2), age group (<40 vs ≥ 40), number of relapses 1 year prior to natalizumab infusion, baseline T2 lesion volume, baseline Gd+ lesions, and MS disease duration, as applicable.

Results: The prespecified year 1 analysis consists of the intent-to-treat population of 209 patients. Baseline characteristics confirm that the study population was an early MS population with a mean (SD) time since diagnosis of 1.6 (0.8) years. At baseline, the mean (SD) EDSS score was 2.0 (1.1), with a range of 0-4. Approximately half (50.2%) of the patients had not received prior disease modifying therapies. A preliminary 1-year analysis performed on 174 patients shows that 96 patients (57.5%) had NEDA at year 1 (95% CI: 50.1%, 64.8%). A full analysis of baseline characteristics predicting NEDA will be presented. In addition to overall NEDA, an analysis of clinical NEDA (no EDSS progression and no relapses) will be presented. The effects of natalizumab across subgroups of patients with ≥1 relapse 1 year prior to the first natalizumab infusion, high vs low T2 lesion volume at baseline, age <40 vs ≥ 40, presence or absence of Gd+ lesions, and disease duration ≤2 years vs >2 years, as well as the cumulative probability of EDSS improvement (including only patients with baseline EDSS score ≥2), will be presented. Preliminary 1-year analyses indicate that the serious adverse events profile is consistent with the well-established safety profile of natalizumab. Key safety data will be described.

Conclusions: In MS patients treated early in their disease course, a large proportion can attain NEDA with natalizumab treatment.