Researchers from the Rocky Mountain MS Center at University of Colorado and New York University are conducting a study to investigate the immune response to the COVID vaccine in multiple sclerosis patients treated with ocrelizumab (Ocrevus).
We recently sat down with the MS Center’s Dr. Amanda Piquet, lead investigator on the study, for some more information.
What is the purpose of this new study?
The purpose of this study is to understand and learn about the immune response to COVID-19 vaccination in patients with multiple sclerosis who are on ocrelizumab (Ocrevus).
Why is this study important?
Since the emergence of the novel SARS-CoV-2 virus that causes COVID-19, we have continued to learn more about it. The duration and nature of immunity generated in response to COVID-19 infection or vaccination is unknown. The immune response is less clear for patients with an autoimmune disease such as MS, and is even less clear for MS patients on an immunosuppressive disease modifying therapy such as Ocrevus.
Are there prior studies that help inform us about this issue?
The VELOCE study evaluated people on ocrelizumab who were fully B cell depleted and looked at antibody responses to known vaccines, including tetanus, pneumococcal and influenza vaccinations. As part of the study, researchers also introduced a neo-antigen (or antigen protein) called KLH. This was unique because you need to have your native B cells recognize that protein and then mount an immune response.
Many patients have probably been exposed to influenza, have been infected with various strands of influenza, or received the influenza vaccine before and after starting ocrelizumab. That virus would serve as an antigen that your immune system has seen before in the past at the time of vaccination with flu. What is unique about SARS-CoV-2 is that it is a novel virus with no prior exposure to the immune system in the past. So, you can almost think of the COVID-19 vaccination as a unique antigen (if you have not had COVID-19 infection) that your immune system has never seen before. The VELOCE study did show that the antibody response was worrisome – patients treated with ocrelizumab had an 11 fold lower antibody response after the KLH administration compared with control participants at 12 weeks. It’s important to note that this study was following only IgG antibody levels to measure immune response. We know that there are other important immune response factors beyond IgG antibody levels, including your neutralizing antibodies and your T cell response. Therefore, an essential part of this new study is that we will examine the vaccine response by following all of these factors: IgG antibody levels, T cell response, and neutralizing antibodies.
How will this study be conducted?
As part of this study, patients will get their ocrelizumab as they normally would through standard of care. We would need to see patients prior to their COVID-19 vaccination to collect pre-vaccination blood. Patients would then need to be vaccinated with either Pfizer or Moderna vaccines as we are studying mRNA vaccine response. After patients get vaccinated, there would be 4 subsequent patient visits – at 4 weeks, 12 weeks, 24 weeks, and 52 weeks – for blood work to measure patients’ immune responses to the vaccine.
This study will be conducted in a partnership between University of Colorado at Anschutz Medical Campus and New York University. It will include 60 patients total, approximately 30 patients in Colorado and 30 patients in New York State.
What are the potential implications of the study findings?
This study is a starting point which is going to launch into additional studies. Those studies will look at key questions, including: Is the timing of ocrelizumab what’s important? Are there booster strategies that could be helpful? What are the best immune response measures to follow – IgG antibody, neutralizing antibodies, or T cell response? Though it is a small study, it will provide important preliminary data to help inform clinicians about what to expect when vaccinating patients on ocrelizumab.