Background: Disease-modifying therapies (DMTs) can reduce the risk of disability worsening in patients with relapsing forms of multiple sclerosis (RMS). High-efficacy DMTs can lead to confirmed or sustained disability improvement (CDI and SDI). Objective and Methods: Post hoc analyses of data from the TRANSFORMS, FREEDOMS, and FREEDOMS II trials and their extensions assessed the effects of fingolimod (0.5–1.25 mg/day) on stabilizing or improving disability over ⩽8 years in participants with RMS. CDI and SDI rates were compared between participants initially randomized to fingolimod, interferon (IFNβ-1a), or placebo. Results: At 8 years’ follow-up in TRANSFORMS, 35.1% (95% confidence interval [CI], 28.2%–43.1%) of assessed participants in the IFNβ-1a–fingolimod switch group and 41.9% (36.6%–47.6%) on continuous fingolimod experienced CDI; disability did not worsen in approximately 70%. Similar results were seen in the combined FREEDOMS population. Proportionally fewer TRANSFORMS participants achieved SDI in the IFNβ-1a–fingolimod switch group than on continuous fingolimod (5.4% [3.0%–9.5%] vs 14.2% [10.8%–18.4%], p = 0.01). Conclusion: CDI and SDI are outcomes of interest for clinical trials and for long-term follow-up of participants with RMS. Monitoring CDI and SDI in addition to disability worsening may facilitate understanding of the therapeutic benefit of RMS treatments.
More than 10 multiple sclerosis-modifying drugs (MSMDs) are widely used now. Novel MSMDs should be investigated in strict accordance with the evidence-based medicine principles governing clinical trials (of both original drugs and their analogues) that prove the high efficiency, safety, and tolerability of new drugs versus the already existing ones. Russia has gained extensive experience in conducting such studies using the well-known drugs as a comparison group. The efficiency and safety of new therapy should be evaluated according to the international criteria on the basis of a sufficient number of patients during a long-term follow-up. When combining the drugs, their efficiency and the risk of adverse effects can vary. The published results of a small study of the combined drug Leucovir (Belarus) do not meet these requirements, and the possibility of using this drug to treat multiple sclerosis can be discussed only after adequate phases II and III clinical trials.
Disability improvement as a clinically relevant outcome in clinical trials of relapsing forms of multiple sclerosis