A recent study has discovered that individuals with primary progressive multiple sclerosis (MS) experience no significant difference in the duration before their disability worsens, whether they are using specific medications or not. This research appears in the online edition of Neurology®, the official journal of the American Academy of Neurology, dated September 25, 2024.
In MS, the immune system erroneously targets myelin, the protective fatty layer surrounding nerves. Those affected by primary progressive MS undergo a gradual deterioration in their symptoms. This type of MS affects approximately 10 to 15% of the patients.
The study focused on two anti-CD20 infusion therapies: rituximab and ocrelizumab. Both target a protein known as CD20 found on certain white blood cells, specifically B-cells. The elimination of these B-cells from circulation is thought to lessen inflammation and mitigate damage to the myelin. While ocrelizumab has been authorized by the U.S. Food and Drug Administration (FDA) for both primary progressive MS and for relapse cases, rituximab is not approved for MS; it is FDA-approved for treating other conditions like rheumatoid arthritis and is used off-label for MS treatment.
“MS is a debilitating condition, so effective treatments that can slow the progression of disability are urgently needed,” remarked the study’s author, Laure Michel, MD, PhD, from Rennes University in France. “Anti-CD20 therapies are commonly prescribed due to the limited treatment options available. However, our study indicates that they may not effectively hinder the worsening of disability in patients with primary progressive MS.”
The research included 1,184 individuals with primary progressive MS, averaging 56 years in age, all of whom had not been on MS medications for the two years preceding the study. Among the participants, 295 received rituximab, 131 were treated with ocrelizumab, while 728 remained untreated. The participants were monitored for an average of four years.
The researchers assessed disability using a scale ranging from zero, indicating no symptoms, to 10, which signifies death due to MS. At the study’s outset, all participants had scores of 6.5 or lower.
They determined the time it took for participants to reach their first verified instance of disability progression. For those starting with scores below 5.5, a progression of one point was accounted as worsening disability, while for those with scores of 5.5 or higher, an increase of 0.5 points indicated disability progression.
After considering potential differences between the treated and untreated groups, researchers concluded that there was no significant difference in the time to progress to the next disability level, whether individuals were taking medications or not.
“MS treatments can be costly and may carry the chance of side effects,” noted Michel. “Our findings suggest that ongoing evaluations of MS therapies are necessary to ascertain whether the benefits justify the risks for patients with primary progressive MS.”
It is important to note that this study had certain limitations, including its retrospective nature and not assessing participants in real time. Additionally, among those who received treatment, a larger proportion took rituximab compared to ocrelizumab. Further research with larger participant groups is required to validate these findings.
This research was funded by the France National Research Agency, the French MS registry, and the Eugène Devic EDMUS Foundation.
