Too soon for B-cell measures?
Commenting for this news organization, Robert J. Fox, MD, staff neurologist at the Mellen Center for MS and vice-chair for research at the Neurological Institute at Cleveland Clinic, Ohio, said the B-cell threshold identified in the study is much higher than what is typically seen in patients who undergo treatment with ocrelizumab, an anti-CD20 B-cell therapy approved in the United States for treating MS.
“Decisions about treatment interval need to balance efficacy in treating MS with safety, including response to vaccines,” said Dr. Fox, who was not involved with the research.
“Given the unknown efficacy of these extended intervals, I don’t think we’re at the point of making management recommendations based upon B-cell counts,” he added.
And yet, Uppsala University Hospital, where the study was conducted, and other centers in Sweden decided to do just that. They suspended administering rituximab to patients with MS until the patients were vaccinated. For patients newly diagnosed with MS, therapy was initiated using another disease-modifying treatment, and for those who were due for a rituximab infusion, that treatment was delayed.
Only one patient experienced a mild MS relapse during the rituximab suspension, and that case went into remission within a week, Dr. Burman reported.
“Ever since the Bar-Or report showing that the humeral response to vaccines is markedly diminished in MS patients treated with anti-CD20 therapies, clinicians have been struggling to balance those safety concerns related to anti-CD20 monoclonal antibody treatments and the clinical benefit of this treatment class,” Dr. Fox said.
“Given the uncharted waters of the COVID pandemic, clinicians made judgments and decisions as best they could, given the paucity of data,” he noted.
“At this point, we don’t know which decisions were right or wrong, but I certainly don’t think we should judge clinicians for making decisions the best they could.”
The study was funded by the Engkvist Foundation, the Marianne and Marcus Wallenberg Foundation, and the Swedish Society for Medical Research. Dr. Burman reported no relevant financial relationships. Dr. Fox has received consulting fees from Genentech/Roche, Biogen, and other companies that promote MS therapies.
A version of this article first appeared on Medscape.com.