Safety and Efficacy of Fingolimod and Natalizumab in Multiple Sclerosis After the Failure of First-Line Therapy: Single Center Experience Based on the Treatment of Forty-Four Patients

BACKGROUND: In Poland, natalizumab or fingolimod treatment can be delivered as a second-line therapy to those patients with relapsing-remitting multiple sclerosis (RRMS) who demonstrated no response to interferon or glatiramer acetate treatment for a minimum of one year. The objective of this study was to evaluate the impact of second-line therapy on the frequency of relapses, the disability progression, and the occurrence of side effects. MATERIAL/METHODS: Analysis covered 44 RRMS patients switched from first- to second-line therapy. The annualized relapse rate, disability progression (assessed with Expanded Disability Status Scale, EDSS) and MRI results (new or enlarged T2 lesions and new Gd-positive lesions) before and after switching were compared. The occurrence of adverse events was also assessed. RESULTS: The annualized relapse rate for second-line therapy was significantly lower than for first-line therapy (0.35±0.74 vs. 2.13±0.87, p=0.00005). Median of EDSS progression with first-line therapy was significantly higher than that with natalizumab or fingolimod treatment (p=0.00002). The mean number of new or enlarged T2 and Gd+ lesions in MRI after one-year second-line treatment was significantly lower in comparison to lesions in MRI performed at the end of the first-line therapy (for T2: 0.61 vs. 4.56, p=0.0004; for Gd+: 0.13 vs. 1.98, p=0.0009). No significant differences in the clinical data, MRI results, and side effects between fingolimod and natalizumab patients have been observed. CONCLUSIONS: Treatment with natalizumab or fingolimod as a second-line therapy in RRMS patients is safe and effective. Less restrictive criteria for switching should be considered.