MULTIPLE SCLEROSIS: The effectiveness of anti-CD20 therapies in question

MS is characterized by an attack by the immune system on myelin, the white, fatty substance that insulates and protects nerves. Around 10 to 15% of affected patients have the primary progressive form.characterized by a progressive and constant worsening of symptoms.

The research is investigating the effectiveness in postponing disability of rituximab and ocrelizumab, anti-CD20 infusion therapies that target a protein called CD20 found on certain white blood cells, or B lymphocytes. Eliminating These cells in the bloodstream reduce inflammation and damage that can occur to myelin.

• Ocrelizumab is approved by the US Food and Drug Administration (FDA) for primary progressive MS and for patients experiencing relapses, but rituximab is not.
• Rituximab is approved by the FDA for other diseases such as rheumatoid arthritis and prescribed off-label for MS.

Lead author Dr Laure Michel of the University of Rennes emphasizes the great need for treatments that slow progression to more severe disability but adds: “While anti-CD20 therapies are widely prescribed, in part because few alternative options exist, our study suggests that they may not slow the worsening of disability in patients with primary progressive MS.” .

The study demonstrated this with 1,184 participants suffering from primary progressive MS, aged on average 56 years old, who had been naïve to MS treatments for at least 2 years. During the 4-year follow-up, 295 people were treated with rituximab, 131 with ocrelizumab and 728 received no medication. The participants’ level of disability was measured on a scale with scores ranging from 0 (absence of symptoms) to 10 (death due to MS). At baseline, participants had a score of 6.5 or less. Time to progression to disability was calculated for each participant. Finally, the analysis notes:

• an absence of difference in the time to progression towards the following disability between the 2 treatment groups, and the controls exempt from treatment.

While MS medications are not only expensive but can cause side effects, these data suggest that

continuously evaluate the patient’s response to treatment

to verify that the benefits outweigh the risks.

Larger and longer (longitudinal) research is planned to confirm these initial data.