I am being asked why I have moved ocrelizumab and other anti-CD20 therapies into the low-risk categories of DMTs in my latest version of my DMT table.
The reasons I use to justify the change are several-fold.
Anti-CD20 therapies deplete B-cells and only have a small impact on T-cell counts and innate immune cell function. This is important because anti-viral responses don’t seem to be affected to a great extent on ocrelizumab and other anti-CD20 therapies. In the phase three ocrelizumab trial programme apart from seeing a small herpes zoster signal there was no clear viral infection signal. When viral infections occurred they tended to be mild or moderate. The severe infections were bacterial (pneumonia, UTIs and cellulitis).
We are seeing an increasing number of patients who have been treated with anti-CD20 therapies who have had COVID-19 doing well. We have just published a case report in MSARDs of a man with PPMS treated with ocrelizumab who did well (see below). This has to be good news for patients on anti-CD20 therapies.
Ocrelizumab also blunts antibody responses, which may be important in severe COVID-19. This may delay or prevent damage to the COVID-19 lung as some of the damage seems to be mediated by complement activation and microthrombi. The latter is indicative of damage consistent with IgG3 anti-viral responses and IgG antibody-dependent cellular cytotoxicity by macrophages and in some instance neutrophils. Antibody production against the SARS-CoV-2 spike protein may promote cytokine production that activates macrophage to become more destructive. Blunting these antibody responses with an anti-CD20 therapy may actually be beneficial, which is why we are predicting that anti-CD20 treated patients will have a lower risk of getting severe COVID-19.
What about hypogammaglobulinaemia then?
Yes, this does occur with anti-CD20 therapies but occurs at a relatively low level. As SARS-CoV-2 is a new human pathogen and hence we don’t have immunological memory against the virus this makes little difference to the risk of becoming infected with SARS-CoV-2. Hypogammaglobulinaemia may, however, put you at risk of getting secondary bacterial infections. Fortunately, these can be treated with antibiotics.
What about vaccine responses?
Yes, anti-CD20 and other immunosuppressive therapies can blunt antibody responses to some vaccines. And yes, contrary to the dogma patients on anti-CD20 therapies do make antibodies to viruses and vaccines. I assume this happens because we still have B-cells in secondary lymphoid organs and/or there may be CD20 negative B-cells that can takeover antibody production. Please note that the latter is a hypothesis.
Antibody responses to glycoproteins (sugar antigens) are particularly affected by anti-CD20 therapies and this may be important in the context of coronavirus immunity as the spike protein is heavily modified with sugar molecules. However, all these arguments are theoretical; until a vaccine emerges I would focus on getting MS treated. We can cross the vaccine bridge if and when it gets built. I am still of the opinion that the government’s strategy is herd immunity and hence the majority of us will at some point become infected with SARS-CoV-2. Waiting for a vaccine that never arises is going to be difficult for individuals; how long can you realistically self-isolate and/or shield?
We are very keen to do an anti-SARS-CoV-2 seroprevalence study in pwMS to see how many have been exposed to the virus and have not developed COVID-19 and to also look at antibody responses to SARS-CoV-2 in patients on different DMTs. We hypothesise that patients on anti-CD20 therapies will have as good an antibody response to SARS-CoV-2 as patients not on anti-CD20 therapies. This hypothesis refers to qualitative antibody responses, i.e. neutralising or protective antibody responses.
For the reasons above I have not stopped offering patients with active MS anti-CD20 therapies during the pandemic. This refers to both starting and retreatment. Some patients have chosen to delay their treatments until the pandemic is over and others have taken my advice and gone ahead with their treatments; this is their choice. But as I have said before the pandemic won’t be over anytime soon; the tail is likely to extend for 18-24 months and possibly longer. Therefore all the guidelines that have recommended delaying or postponing treatment with depletion therapies, i.e. the anti-CD20s, cladribine, alemtuzumab, mitoxantrone, cyclophosphamide and HSCT will have to be reviewed. We can’t stop treating MS or offering patients less effective options for the next 18-24 months. If we do what will be the consequences?
How many swallows does it take to make a summer? I am aware that one case report is not much, but there are an increasing number of patients being reported on social media who have been treated with an anti-CD20 and have had gotten through COVID-19 without a problem.
I would urge all the national register studies to be please report your data on COVID-19 outcomes in pwMS as soon as possible. We need the data to formalise our treatment guidelines and to help allay the fears of our patients. Please use one of the archive repositories to get your data out to the MS community as soon as possible. Thank you.
Giovanni Novi et al. COVID-19 in a MS Patient Treated With Ocrelizumab: Does Immunosuppression Have a Protective Role? Mult Scler Relat Disord 2020 Apr 15;42:102120.
Background: Coronavirus disease 19 (COVID-19) is a novel disease entity that is spreading throughout the world. It has been speculated that patients with comorbidities and elderly patients could be at high risk for respiratory insufficiency and death. Immunosuppression could expose infected patients to even higher risks of disease complications due to dampened immune response. However, it has been speculated that overactive immune response could drive clinical deterioration and, based on this hypothesis, several immunosuppressants are currently being tested as potential treatment for COVID-19.
Methods: In this paper we report on a patient that has been treated with ocrelizumab (a B-cell depleting monoclonal antibody) for primary progressive multiple sclerosis who developed COVID-19.
Results: Despite complete B cell depletion, patient symptoms abated few days after hospitalization, and he was discharged to home-quarantine. Phone interview follow-up confirmed that, after 14 days, no new symptoms occurred.
Discussion: This report supports the putative role of immunosuppressive therapy in COVID-19 affected patients.