Delaying the inevitable: Are disease modifying drugs for progressive MS worthwhile?

Area of Science:

• Neuroscience
• Immunology
• Clinical Pharmacology

Background:

• Progressive multiple sclerosis (MS) is a debilitating neurological condition.
• Ocrelizumab and siponimod are approved treatments for progressive MS, demonstrating short-term efficacy in reducing disability.
• Traditional efficacy metrics like hazard ratios are difficult for patients to interpret.

Purpose of the Study:

• To evaluate the long-term clinical benefit of ocrelizumab and siponimod in progressive MS.
• To translate hazard ratio data into a more patient-understandable metric: average postponement of disability.

Main Methods:

• Analysis of pivotal trial data for ocrelizumab and siponimod.
• Calculation of average postponement of disability based on 3-month confirmed disability progression endpoints.
• Assessment of treatment effect over time to identify potential plateaus in efficacy.

Main Results:

• Ocrelizumab and siponimod showed hazard ratios between 0.76-0.79 for disability progression.
• After two years, average postponement of disability was 16 days/year for ocrelizumab and 19 days/year for siponimod.
• The average postponement of disability reached a plateau, indicating diminishing returns with continued treatment.

Conclusions:

• While ocrelizumab and siponimod demonstrate statistically significant short-term benefits in progressive MS, the clinical impact is modest.
• The average postponement of disability suggests a limited and short-lived effect, questioning the long-term value of these treatments.
• Further research into more impactful treatments for progressive MS is warranted.