Interferons, Glatiramer Acetate, and Minocycline for Relapsing-Remitting Multiple Sclerosis and Clinically Isolated Syndrome
Authors: CADTH  
Published: June 2024

What Is the Issue?

Multiple sclerosis is a chronic autoimmune disorder that causes damage to central nervous system cells. Relapsing-remitting multiple sclerosis is characterized by relapses (episodes of new or worsening symptoms) followed by periods of partial or complete recovery (remission). A clinically isolated syndrome is the first episode of clinical symptoms and objective findings suggestive of multiple sclerosis. It lasts at least 24 hours and occurs without fever or infection.
Disease-modifying therapies for multiple sclerosis include interferon beta-1a and interferon beta-1b, and glatiramer acetate.
Minocycline is an antibiotic that may have a potential role in treating multiple sclerosis. Understanding its possible benefits and harms in clinically isolated syndrome and relapsing-remitting multiple sclerosis is important to clarify its potential role in these patients.

What Did We Do?

The purpose of this report is to update 2 previous reports we conducted in 2019. We summarize the evidence regarding the clinical effectiveness of glatiramer acetate, interferon beta-1a, and interferon beta-1b for clinically isolated syndrome, as well as minocycline for clinically isolated syndrome and relapsing-remitting multiple sclerosis. Evidence-based guidelines were also summarized.
We searched key resources, including journal citation databases, and conducted a focused internet search for relevant evidence published since 2019. One reviewer screened articles for inclusion based on predefined criteria, critically appraised the included studies, and narratively summarized the findings.

What Did We Find?

We found 1 systematic review that evaluated the safety of interferon beta-1a and glatiramer acetate in patients with clinically isolated syndrome.
Serious adverse events and withdrawals due to adverse events were similar in patients with clinically isolated syndrome who received interferon beta-1a and placebo.
Serious adverse events were similar in patients with clinically isolated syndrome who received glatiramer acetate and placebo. Withdrawals due to adverse events were more common in patients with clinically isolated syndrome who received glatiramer acetate than placebo.
We did not identify any studies that evaluated the clinical effectiveness of interferon beta-1a, interferon beta-1b, glatiramer acetate, or minocycline in patients with clinically isolated syndrome, or minocycline in patients with relapsing-remitting multiple sclerosis published since our previous reports. We did not identify any evidence-based guidelines published since our earlier reports.

What Does This Mean?

It is uncertain if interferon beta-1a, interferon beta-1b, glatiramer acetate, and minocycline are effective treatments for clinically isolated syndrome, or if minocycline is an effective treatment for relapsing-remitting multiple sclerosis due to the lack of evidence identified in this report.
Future studies are needed to understand the clinical effectiveness of interferon beta-1a, interferon beta-1b, glatiramer acetate, and minocycline in patients with clinically isolated syndrome, and minocycline in patients with relapsing-remitting multiple sclerosis.