Tag: coronavirus

#MSCOVID19: CATCH-22

Barts-MS rose-tinted-odometer: ★

I know it sounds like a cliche but Catch-22 would definitely be on my list of most impressionable books I read as a teenager.  I liked it because of its dark satirical humour, it was written in the third-person and it taught me how absurd war actually is. Catch-22 (and the Great Gatsby) also taught me if you love a book you should never watch the movie; the screenwriters, actors and directors can never do your imaginary characters justice. 

The book has become so influential that ‘Catch-22’ has become a noun and refers to a dilemma or difficult circumstance from which there is no escape because of mutually conflicting or dependent conditions. 

Although I am meant to be at home recovering from injuries I am doing some emails. Over the last few days, I have received numerous emails from patients and neurologists asking for advice about COVID-19/SARS-CoV-2  vaccines and DMTs and what am I telling my patients. One patient tells me that her neurologist referred her the excellent MS Society webpage for advice, but the site then referred her back to her neurologist for definitive advice. A Catch-22?

Some US neurologists have picked-up that my advice and position on vaccines and vaccine readiness has changed since I first started talking about this issue on the blog. They are correct, my position has changed. I always took the position that we should continue to manage MS the way we managed it before COVID-19 with certain caveats* around the risk of being exposed to SARS-CoV-2 and whether or not individuals could self-isolate or not, and that we should cross the vaccine bridge when it arrives. Now that the vaccines are arriving and the ambitious national roll-out suggests the whole country will be vaccinated within the next 6 months, advice has to be given and given quite quickly. 

In my opinion, all the COVID-19 vaccines that the UK Government has purchased can be used in people with MS regardless of whether or not they are on a DMT. This advice is based on the fact that the MHRA and other regulatory bodies have licensed or will license these vaccines because of their safety and efficacy profile in the general population. 

Importantly none of these vaccines is likely to be a ‘live viral vaccine’. There is some confusion around the Oxford-AstraZeneca vaccine that does use a chimpanzee adenovirus vector to deliver the immunogen to our cells so that the immunogen can be expressed. The virus in this vaccine is able to infect cells and express its relevant proteins, but because some of its genes for replication have been mutated it cannot replicate itself and cause ongoing infection. I am not sure how this vaccine will be classified by the MHRA or other regulatory authorities, but in my opinion, it is likely to be safe to use in pwMS. 

I say these vaccines are likely to be safe in pwMS. However, none of the COVID-19 vaccines has specifically been tested in pwMS so we have to extrapolate data from the general population data. There may be something we don’t know about having MS that predisposes pwMS to some rare complications. However, based on other vaccines that have been used in MS this is very unlikely. 

It is clear that being on some immunosuppressive DMTs may reduce your chances of responding adequately to the vaccine and hence being fully immune to infection from wild-type SARS-CoV-2. Until we do detailed immunological studies in pwMS on each DMT we won’t be able to answer specific questions about each DMT with certainty. 

Interferon-beta , glatiramer acetate and immune reconstitution therapies

In general being on interferon-beta and glatiramer acetate, immunomodulatory DMTs, are unlikely to interfere with vaccine responses. Similarly, if you have had one of the immune reconstruction therapies, such as alemtuzumab, cladribine, mitoxantrone or HSCT in the past and have reconstituted your peripheral immune system you should respond to the vaccines. If on the other hand, you have not had completely reconstitution of your immune system you may still consider having the vaccine, but the immune response may be blunted. Waiting for immune reconstitution or having the vaccine now will be a trade-off between wanting to protect yourself now or waiting months when the pandemic may be almost over. Please note vaccination is not only about you, but slowing and preventing transmission of the virus in the general population, which is a factor you may want to consider. This may relevant, for example, if you want to see unvaccinated vulnerable relatives or if you want to travel to parts of the world with a delayed vaccination programme.  

Fumarates, teriflumide and natalizumab

If you are fumarates (DMF,  diroximel fumarate), teriflunomide or natalizumab, based on other vaccine studies, COVID-19 vaccine responses are likely to be reasonably preserved. Therefore there is no need to stop these DMTs or delay getting a vaccine if you are on these treatments. 

S1P modulators

For the so-called S1P modulators (fingolimod, siponimod, ozanimod and ponesimod) vaccine responses are likely to be blunted, but whether or not the blunted responses will be sufficient to prevent SARS-CoV-2 infection is a moot point.  However, I would not recommend stopping these treatments to have a vaccine as these therapies are associated with MS rebound activity. My advice would be that if you are on these therapies to go ahead with the vaccine when it is offered to you. 

Anti-CD20 therapies

When I initially wrote about vaccine hesitancy I suggested that pwMS on an anti-CD20 therapy (rituximab, ocrelizumab, ofatumumab) may have to delay their next infusion or miss one or two infusions to allow B-cell reconstitution before they have a coronavirus vaccine. Since making this statement more immunological data has emerged and there really is no definitive evidence to support this position. 

Yes, I agree that in general people on anti-CD20 therapies have blunted antibody responses to wild-type SARS-CoV-2 infection and to other vaccines including vaccines with containing new antigens that the immune system has not seen before. However, this doesn’t mean these people haven’t developed immunity to the infection or vaccine that is long-lasting. For one the vast majority of pwMS on an anti-CD20 therapy who get COVID-19 make an uneventful recovery. Why? Almost certainly this recovery is due to cellular and not humoral (antibody) immunity and this immunity won’t vanish and is likely to persist longterm. 

Even normal people who have had COVID-19 and who lose their antibody responses still have detectable cellular immunity. My interpretation of this data is that pwMS who are on an anti-CD20 therapy should simply go ahead and have the coronavirus vaccine when it is offered to them and not to worry about whether or not they mount an antibody response. 

I am aware that some pwMS are planning to delay their next infusion regardless of what I or their HCP says. The question I ask is for how long? One, two, three or more months? Some pwMS plan to wait for peripheral B-cell reconstitution that can take months to years to occur and even then there is no consensus of what normal B-cell reconstitution looks like. You need to weigh the lack of evidence that delaying your next anti-CD20 therapy or waiting for B-cell reconstitution will make any difference to your vaccine response against the time-sensitive nature of the vaccine to protect you during the high-risk period of the pandemic. If you wait too long and the pandemic is over the benefits of the vaccine will be reduced. 

The only evidence base we have at the moment is the recently published VELOCE study that delayed vaccination until 12 weeks after an initial course of ocrelizumab. This study showed blunted, but not absent, antibody responses to recall and new vaccines. Based on this study if you have just had a recent course of ocrelizumab you may want to delay getting the COVID-19 vaccine for 12 weeks after the last infusion. However, as 12 weeks is a long time to wait in the current climate I have been recommending at least 4 weeks; a pragmatic compromise.

In my opinion, it is more important for pwMS on anti-CD20 therapies to be vaccinated than to not be vaccinated. This is because vaccination policy is really about population, or subpopulation, health and stopping the spread of the virus and protecting the individual is a secondary aim. 

MS relapses

Will the COVID-19 vaccines trigger MS relapses? This hypothesis is based on extrapolating data on two non-peer-reviewed cases of CNS demyelination in the Oxford-AstraZenca (Ox-AZ) trial and several cases of transverse myelitis in patients who have had COVID-19. One case on in the Ox-AZ trial, who received the vaccine, had an initial attack or relapse and was subsequently diagnosed as having MS; i.e. I assume because they had pre-existing lesions and were now shown to have a second attack or new lesions consistent with dissemination in time. The other case had an episode of vaccine-related transverse myelitis (TM), which is relatively common with vaccines in general. Please note that vaccine-related TM is not MS. The only vaccine that has been reported to potentially trigger MS relapse is the live yellow-fever vaccine and this is based on one report that has subsequently not been replicated. Therefore, there is no current evidence that coronavirus infection or coronavirus vaccines trigger MS relapses. In my opinion, there is no reason to avoid the COVID-19 vaccine based on this hypothesis. Clearly, my opinion may change if new data emerges to the contrary.

Summary

If you have not had COVID-19 having a vaccine will offer you the opportunity of preventing getting COVID-19 or at least if you do get it, of having milder disease. All the licensed vaccines, which have been shown to be safe in the general population are likely to be safe in pwMS. Although some people on immunosuppressive therapies, in particular, S1P modulators and anti-CD20 therapies, may have blunted antibody vaccine responses these may still be sufficient to protect you against infection or at least severe COVID-19. There is no evidence that stopping or delaying treatment, in the hope of boosting vaccine responses will work and may result in you missing out on being protected when your risk of infection is highest. Please be aware that stopping some DMTs, in particular, natalizumab and S1P modulators, is associated with a rebound of disease activity and is not recommended. Hopefully, the pharmaceutical industry and the wider MS community will collect data and do specific studies to answer the many questions we have around vaccination and vaccine responses in pwMS on specific DMTs. 

* The caveats refer to alemtuzumab and HSCT, which affect both innate (monocytes and/or neutrophils) and adaptive (particularly cytotoxic CD8+ T lymphocytes), which are required for fighting SARS-CoV-2. My advice for the other DMTs has not to self-isolate, but to simply stick to the current government guidelines in relation to social distancing and personal hygiene. 

Bar-Or et al. Effect of ocrelizumab on vaccine responses in patients with multiple sclerosis: The VELOCE study. Neurology October 06, 2020; 95 (14) 

Objective: The phase IIIb VELOCE study (NCT02545868) assessed responses to selected vaccines in ocrelizumab (OCR)-treated patients with relapsing multiple sclerosis.

Methods: Patients were randomized 2:1 into Group OCR (n=68; OCR 600mg); or Control (n=34;interferon-β or no disease-modifying therapy). All received tetanus toxoid (TT)-containing vaccine, Pneumovax® (23-PPV) and keyhole limpet hemocyanin (KLH). Group OCR was subdivided into OCR1 (n=33) and OCR2 (n=35) at randomization. OCR1 received Prevnar® (13-PCV) 4 weeks after 23-PPV; OCR2 and Control received influenza vaccine. Vaccinations started 12 weeks after OCR initiation (Group OCR) or on Day 1 (Control).

Results: Positive response rate to TT vaccine at 8 weeks was 23.9% in OCR vs 54.5% in Control. Positive response rate to ≥5 serotypes in 23-PPV at 4 weeks was 71.6% in OCR and 100% in Control. Prevnar® did not enhance response to pneumococcal serotypes in common with Pneumovax®. Humoral response to KLH was decreased in OCR vs Control. Seroprotection rates at 4 weeks against five influenza strains ranged from 55.6–80.0% in OCR2 and 75.0–97.0% in Control.

Conclusion: Peripherally B-cell depleted OCR recipients mounted attenuated humoral responses to clinically relevant vaccines and the neoantigen, KLH, suggesting use of standard non-live vaccines while on OCR treatment remains a consideration. For seasonal influenza vaccines, it is recommended to vaccinate patients on OCR, as a potentially protective humoral response, even if attenuated, can be expected. Classification of evidence This study provides Class II evidence confirming that the humoral response to non-live vaccines in patients with RMS following ocrelizumab treatment is attenuated compared with untreated or interferon-β–treated patients, though can still be expected to be protective.

Twitter: @gavinGiovannoni                                   Medium: @gavin_24211

#MSCOVID19: good news

Barts-MS rose-tinted-odometer: ★★★★★

The late late-breaking session at the MSVirtual2020 meeting, which covered COVID-19 has already received a lot of air-time on social media. The big-data alliance confirmed the Italian data, i.e. that people with MS (pwMS) on anti-CD20 are at higher risk of getting COVID-19 and severe COVID-19 (hospitalisation, intensive care admission and/or ventilation) compared to pwMS on dimethyl fumarate. Importantly there was no mortality signal, i.e. pwMS on anti-CD20 don’t appear to be at higher risk of dying from COVID-19 and its complications. This is very good news! 

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However, the Big-Data alliance couldn’t confirm what the Italians have shown that treatment duration on an anti-CD20 is a risk factor. A clue to the latter is the observation that the COVID-19 risk was higher with rituximab compared to ocrelizumab in the Big-Data alliances graphs. As it is likely that rituximab-treated pwMS have been on treatment longer than ocrelizumab-treated patients would support this. Ocrelizumab has only recently been licensed and hence most people on ocrelizumab are likely to have been on it for a shorter period of time compared to rituximab-treated patients. 

Is all this good news? Yes, very good news. 

It clearly shows that people on anti-CD20 therapy have the ability to mount a robust immune response and recover from coronavirus infections, despite having a reduced B-cell and antibody response. This means that innate immunity and adaptive cellular immune responses are all that is required to recover from coronavirus and other viral infections. It will be important to study how robust the T-cell memory responses are post-COVID-19 in these patients as this will have implications for studying vaccine response when vaccines arise. What this means is that even if pwMS on an anti-CD20 don’t make an antibody response to a SARS-CoV-2 vaccine they may still have protective cellular immunity. This will also be good news. I sincerely hope Roche-Genentech and Novartis are planning to study vaccine responses in ocrelizumab- and ofatumumab-treated patients when the vaccines arrive. 

The observation that the longer you have been on an anti-CD20 the greater your chances of getting COVID-19 and severe COVID-19 implies the risk may be related to hypogammaglobulinaemia and blunting of past cross-reactive immunity from being exposed to other circulating community-acquired coronaviruses. I illustrate this in the following slide. In short pwMS on anti-CD20 therapy are shifted to the right and are less likely to have asymptomatic infections and more likely to have severe infections. 

This cross-reactive immunity to other coronaviruses may be the silver lining to the ominous grey clouds that have been hanging over us for months. It seems that between 40-60% of people in the general population have T-cell responses to SARS-CoV-2 without a history of having had COVID-19 and without an anti-SARS-CoV-2 antibody response. It now seems that these cellular memory responses protect these individuals from getting COVID-19. If this proves to be the case then herd immunity might be much higher than we realise and this could explain why the second surge in places like London and New York are much lower than other places that had smaller peaks during the initial wave of COVID0-19. 

If this background cross-reactive coronavirus immunity hypothesis, backed by the observations we see in pwMS on anti-CD20 therapy, turns out to be true we may have already reached herd immunity in London and are not far off it in other areas of the country. New models by Gomes and colleagues, at the University of Strathclyde, and Lourenco and colleagues, at the University of Oxford, suggest herd immunity may occur at levels of exposure of 20% or lower. If this is the case then we will see it first in London. So please watch the London COVID-19 numbers if they stay low this will be very good news. 

Gomes et al. Individual variation in susceptibility or exposure to SARS-CoV-2 lowers the herd immunity threshold. MedRxIV doi: https://doi.org/10.1101/2020.04.27.20081893

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads, the susceptible subpopulation is depleted causing the incidence of new cases to decline. Variation in individual susceptibility or exposure to infection exacerbates this effect. Individuals that are more susceptible or more exposed tend to be infected earlier, depleting the susceptible subpopulation of those who are at higher risk of infection. This selective depletion of susceptibles intensifies the deceleration in incidence. Eventually, susceptible numbers become low enough to prevent epidemic growth or, in other words, the herd immunity threshold (HIT) is reached. Although estimates vary, simple calculations suggest that herd immunity to SARS-CoV-2 requires 60-70% of the population to be immune. By fitting epidemiological models that allow for heterogeneity to SARS-CoV-2 outbreaks across the globe, we show that variation in susceptibility or exposure to infection reduces these estimates. Accurate measurements of heterogeneity are therefore of paramount importance in controlling the COVID-19 pandemic.

Lourenco et al. The impact of host resistance on cumulative mortality and the threshold of herd immunity for SARS-CoV-2. MedRxIV doi: https://doi.org/10.1101/2020.07.15.20154294

It is widely believed that the herd immunity threshold (HIT) required to prevent a resurgence of SARS-CoV-2 is in excess of 50% for any epidemiological setting. Here, we demonstrate that HIT may be greatly reduced if a fraction of the population is unable to transmit the virus due to innate resistance or cross-protection from exposure to seasonal coronaviruses. The drop in HIT is proportional to the fraction of the population resistant only when that fraction is effectively segregated from the general population; however, when mixing is random, the drop in HIT is more precipitous. Significant reductions in expected mortality can also be observed in settings where a fraction of the population is resistant to infection. These results help to explain the large degree of regional variation observed in seroprevalence and cumulative deaths and suggest that sufficient herd-immunity may already be in place to substantially mitigate a potential second wave.

CoI: multiple

Twitter: @gavinGiovannoni  Medium: @gavin_24211

#MSCOVID19: the new lepers?

Barts-MS rose-tinted-odometer: ★★★

Early this week my wife came down with a cold. Did she have coronavirus was the immediate question? She asked me for advice and I said she had better get herself swabbed and in the interim we should isolate ourselves. All she had was a mild headache (sinus-type), runny nose, sneezing and a sore throat. She did not have a temperature and only developed a mild cough after a few days. Her nasopharyngeal swab for coronavirus done via the post took almost 72 hours to come back and was fortunately negative. 

Interestingly despite a blocked and runny nose, she did not develop loss of smell or her taste; I tested it with coffee, chocolate and some fine white wine. Although loss-of-taste (ageusia) and smell (anosmia) occur in about 40-60% of subjects with COVID-19 it is really not specific enough to exclude coronavirus infection so don’t rely on it. In addition, it may not occur until several days into the infection, prior to which you could be highly infectious and spreading the virus.

Fortunately, my wife is now much better. I suspect she had rhinovirus infection, a common cause of rhinitis or the ‘common cold’, which is now circulating as it normally does this time of year.

In response to the emerging rhinovirus problem, the BBC and most of the newspapers have run articles or special features to highlight the differences between COVID-19, influenzae and the common cold. If you look at this list of symptoms below it is simply not possible to differentiate mild infections from each virus apart. Surely, it is not about diagnosing which infection you have but making sure you don’t act as a source of coronavirus and spread the infection. 

Therefore everyone with symptoms suggestive of an upper respiratory tract infection, including the common cold, should really consider themselves infected with coronavirus until proved otherwise. This means they need to get themselves swabbed and tested. Therein lies the problem. The UK at the moment does not have enough testing capacity outside of the NHS Trust’s to deal with this emerging problem. Hence anyone with a cold will probably have to self-isolate including their immediate contacts.  

The other thing is the new ‘COVID-19 leper syndrome’. Even if you go outdoors or travel, for example, to work, with a blocked nose and cold-like symptoms people will treat you like a leper and run a mile. This has been happening already before the rhinovirus problem; if anyone sneezes or coughs on the underground they immediately attract dirty looks and space clears around them as if they are radioactive. 

Things are only going to get worse the further we move into Autumn and Winter. In addition, young children are back in school and they are hothouses for acquiring and spreading viruses. The perfect storm is having two highly infectious viruses, which cause overlapping symptoms, circulating at the same time when we are trying to get society moving again. I can only imagine the chaos this going to cause in schools, universities and the workplace. The only solution is for the government to massively increase testing capacity ideally with the emerging point-of-care diagnostics, which can provide an answer within 60-90 minutes whether or not you have COVID-19. 

It is clear to me that an effective coronavirus vaccine can’t come soon enough. 

CoI: multiple

Twitter: @gavinGiovannoni Medium: @gavin_24211

#MSCOVID19: getting ready for the vaccine

Informing patients about their potential coronavirus risks associated with anti-CD20 therapy is complicated and resulting in our patients being given different advice depending on who they see. The reason for this is that we don’t have the direct evidence to be able to dissect out why people on anti-CD20 therapy are at higher risk of COVID-19 and at higher risk of being admitted to hospital with severe COVID-19. 

I doubt this increased risk relates to increased exposure to the coronavirus. Why should someone on ocrelizumab who attends their healthcare facility be at increased risk of acquiring SARS-CoV-2 infection compared to someone for example on natalizumab who attends for their infusion every 4-6 weeks? 

The clue to the increased risk is in the detail of the data. It is apparent that the longer you have been on an anti-CD20 therapy the greater your risk; the risk of COVID-19 is particularly high if you have been on an anti-CD20 therapy for more than 3 years. This means that it must be due to prior exposures, i.e. exposures before the COVID-19 pandemic started.  

In the general population, it is now clear that some people have T-cells and antibodies that cross-react with SARS-CoV-2 and that these protect these people from developing COVID-19 or severe COVID-19. These cross-reactive immune responses are likely to have developed in response to infection or exposure to other circulating coronaviruses; the viruses that cause the common cold. 

My theory is that if you are on an anti-CD20 therapy with no B-cells and a poorly functioning antibody response and you get the common cold your immune system will not be able to make these protective cross-reactive anti-coronavirus antibodies. This would then reduce your chances of being protected from getting COVID-19 or getting only mild COVID-19 when you are infected with SARS-CoV-2. 

I have tried to illustrate this in the following slide showing that people on long-term anti-CD20 therapies are more likely to get symptomatic SARS-CoV-2 infection, i.e. COVID-19, and when they do get COVID-19 it is likely to be more severe. Severity in this context is requiring hospitalisation and potential intensive care and ventilation. 

What does this mean for you? It means that if you are about to start ocrelizumab, rituximab or ofatumumab then your chances of getting COVID-19 are unlikely to be different to another DMT, with the exception of interferon-beta that lowers your risk because of its antiviral effects. 

If you happen to be on ocrelizumab, rituximab or ofatumumab already there is little you can do, because these agents are not rapidly reversible and even if you stop the treatment and allow your B-cell compartment to reconstitute you are unlikely to develop the cross-reactive immunity from common coronaviruses. However, by stopping your anti-CD20 and allowing your B-cells to reconstitute you will be allowing your immune system to prepare itself for a coronavirus vaccine in the future.

At the beginning of the pandemic, I was a bit cynical about the chances of a successful coronavirus vaccine emerging, but the preliminary phase 2 results of several vaccines and the immunological insights above have made me much more optimistic that we will have an effective coronavirus vaccine quite soon. When I say soon I suspect we will have one ready for general consumption early next year. In all likelihood, one of the first vaccines will be the Oxford-AstraZeneca vaccine that happens to involve a live virus, which itself will have implications for some of the MS DMTs. 

If my predictions are correct the MS community may need to start getting vaccine ready or they can simply rely on herd immunity. With anti-CD20 therapy, this needs to be planned ahead and patients will need to miss one, two or possibly three infusions depending on their body size and individual B-cell reconstitution kinetics in order to prepare their immune systems for the vaccine. 

Some critics of this strategy are saying that patients on an anti-CD20 therapy will still make T-cell responses to the vaccine that will in all likelihood protect them. Yes, this may be the case, but then how do you explain the above observations that people on anti-CD20 therapy are at increased risk of COVID-19 and severe COVID-19? I would interpret this as them having blunted T-cell responses to cross-reactive common coronaviruses. If this is the case pwMS on an anti-CD20 will have blunted T-cell response to the vaccine. In support of the latter is the observation that several pwMS on ocrelizumab who have had swab-positive COVID-19 have failed to make an antibody response to the virus. Please remember that good quality antibody responses are T-cell dependent. These observations are telling me that in all likelihood being on anti-CD20 therapy will prevent you from developing protective immunity to coronavirus from a vaccine.

Clearly getting more detailed population-level COVID-19 data in people with MS is very important. This is why we are trying to crowdfund our study to identify people who have antibodies to SARS-CoV-2. We will be able to use this resource to do nested immunological studies on pwMS on different DMTs to understand the cross-reactive immunology at both the T and B cell level to coronaviruses in general and test the hypotheses above. It will also allow us to study vaccine responses if and when the vaccines arrive. 

If you are prepared to help with a small donation it would be much appreciated. Thank you.

JustGiving

CoI: multiple

#COVIDMS DMT use during the COVID-19 epidemic needs to be more pragmatic

I saw several patients in clinic yesterday and had to speak to many on the phone about what to do about the next course of ocrelizumab and cladribine. It got me thinking.

According to the Italian society of neurology or SIN (Società Italiana di Neurologia) recommendations on the management of patients with MS during the COVID-19 epidemic we should stop dosing. However, the SIN guidelines don’t address the temporal sequence of the COVID-19 epidemic and how the epidemic may evolve.  The SIN guidelines provide relatively straightforward, and I would argue arbitrary, advice on how to manage patients with MS in the short-term, but they don’t address how to manage these patients in the intermediate or long-term and in particular patients with highly active MS. If the public health measures flatten the peak of the epidemic, but extend its tail, the problem of community-acquired COVID-19 infection may be with us for many months and potentially years. Do we stop using these treatments for years?

Over the last few days, I have asked myself are the SIN guidelines compatible with the best interests of our patients or do they represent a knee jerk response to an undefined problem that may not be a problem at all? 

I had a discussion about the COVID-19 epidemic with our renal transplant team who informed me that they are not taking any specific action about the levels of immunosuppression they are providing their transplant patients during the epidemic. Apart from informing their transplant patients to improve their hand and home hygiene, to avoid high-risk travel and unnecessary contacts, to self-isolate if necessary and to reduce contact with the hospital and other medical institutions as much as possible, because they are more likely to be sources of COVID-19. It is business as usual. Nor are they halting their transplant programme. Their argument is that transplanted kidneys and other transplanted organs are too precious not to protect them with relevant immunosuppressive drugs. Why would we not have the same attitude about the brains and spinal cords of our patients with active multiple sclerosis?

I would argue that solid-organ transplant patients are significantly more immunocompromised than pwMS on a DMT. Most transplant patients are on triple immunotherapy, compared to pwMS who are on monotherapy and even then the level of immunosuppression is generally low on MS DMTs. Hence, the mortality risk to an individual on a DMT, who is unfortunate to be infected with COVID-19, maybe actually quite low.  Another hypothesis being considered is that moderate immunosuppression may prevent severe complications associated with COVID-19 infection. The severe pulmonary complications of COVID-19 infection appear to be consistent with ARDS (acute respiratory distress syndrome) caused by an over-exuberant immune response to the virus. As a result of this, several exploratory trials are currently being undertaken in China using immunosuppressants to try and dampen the immune response to the virus. Interestingly, fingolimod the S1P modulator, a licensed DMT for MS, is currently being tested as a treatment for COVID-19 associated ARDS. 

Then there is the virology to take into account. COVID-19 is a new human pathogen, that is likely to have recently crossed species.  COVID-19 will eventually become endemic and hence pose a seasonal risk to patients on immunosuppressive therapies. As it is a small RNA virus with low fidelity it is likely to mutate rapidly making a one-off vaccine only a partial solution. Vaccines take time to be developed, tested and introduced at a population level. Delaying treatment, de-escalating therapy by switching to immunomodulatory DMT, or interrupting dosing of DMTs to wait for a vaccine will delay the adequate treatment of MS. We, therefore, need a pragmatic response to how we manage the potential threat of COVID-19 in individuals with MS. If patients have active MS they need to be treated and managed based on the clinical evidence at hand and hence may need to be treated with higher efficacy DMTs. This will need to be done in the context of appropriate behavioural modifications to prevent exposure to the virus. 

The potential risks posed by each DMT differ and, rather than imposing a blanket rule, decisions regarding treatment should be individualised. For some patients having their MS treated and controlled may be more important than the potential risk of being exposed to and acquiring a severe COVID-19 infection. 

Based on the immunological principles that antiviral responses are mainly driven by T-cells, in particular CD8+ cytotoxic T-lymphocytes, and natural-killer cells and less so, at least initially, by B-cells. Based on these principles there is a hierarchy of immunosuppression of the DMTs. The highest risk will be the immune reconstitution therapies during the depletion phase of the treatment, i.e. HSCT, alemtuzumab (Lemtrada), mitoxantrone (Novantrone) and possibly cladribine (Mavenclad). However, post-immune reconstitution once the total lymphocyte counts have returned to normal the risk of severe viral infections are probably no higher than what would occur in the background population and would be associated with age and other comorbidities. Please note immune reconstitution takes months to years, so if the patient’s last course of treatment was in the last 12-24 months they may still be immunocompromised. As a rough guide if the total lymphocyte count is above 0.8 x 109/L or 800/mm3 they should be able to deal with viral infections reasonably well provided they have not other comorbidities and are relatively young. 

Of the IRTs, cladribine (Mavenclad) should be classed as being of intermediate risk, because it is a relatively poor T-cell depleting agent. T-cells are only depleted post-cladribine by an average of 50% with the CD4+ population being more sensitive than the CD8+ population. In the Phase 3 CLARITY study, viral infections were uncommon post-cladribine and apart from herpes zoster, infections were only slightly more common in cladribine-treated subjects compared to placebo-treated subjects. When viral infections occurred post-cladribine they tended to be mild or moderate in severity. Therefore I think cladribine should be classified as relatively low-risk DMT.

Similarly, anti-CD20 therapies such as ocrelizumab have a minor impact on T-cell counts and are not associated with severe viral infections. In the Phase 3 relapsing-remitting and primary progressive trials infections were more slightly more frequent on ocrelizumab compared to comparator arms (interferon-beta-1a or placebo). Most of these infections were mild and moderate with the severe infections being bacterial in nature (pneumonia, urinary tract infections and cellulitis). Similar to cladribine there was a small risk of herpetic infections, which were mild to moderate and manageable with antiviral agents. I, therefore, feel that anti-CD20 therapies are relatively safe based on their profiles defined in phase 3 trials and we should continue to use them in patients that need them.

Another issue is neutralizing anti-drug antibodies. If you interrupt dosing of ocrelizumab, say after the first course, you may prevent high-zone tolerance from kicking in, i.e. the immunological mechanism that results in the immune system tolerizing itself to foreign proteins. This means that not continuing ocrelizumab therapy may increase the chance of a particular patient developing NABs and being a poor responder to the drug when it is recommenced.

Clearly any decision to start a DMT during the COVID-19 epidemic will need to be taken carefully and will depend on the state of the COVID-19 epidemic, not only in the particular country concerned, but in the specific area, the patient lives and is being treated in. For example, aggressive public health steps to contain the spread of the virus locally may make it relatively safe for a patient to start an immunosuppressive therapy. My concern is that the COVID-19 epidemic may trigger a large number of neurologists and patients to reconsider their treatment strategy and choice of initial DMT and to opt for less effective immunomodulatory DMTs. A change in treatment strategy driven by COVID-19 needs to be carefully considered. The COVID-19 epidemic in all likelihood will be short-lived and it would be unfair to patients treated during the epidemic to be disadvantaged in the long term regarding the management of their MS. We have spent an extraordinary amount of time and effort to activate the MS community; to get across the principle that ‘time is brain’, to treat MS proactively to a target of no evident disease activity (NEDA) and more recently to flip the pyramid and use higher efficacy treatments first line. These treatment principles are evidence-based and should not be thrown out in the context of a potential but yet undefined risk to our patients that in my opinion is being overemphasised; please remember we have no data on COVID-19 infection in patients with MS on DMTs. 

Is there anything we learn from renal transplant physicians? Yes, with the possible exceptions of alemtuzumab, HSCT and mitoxantrone, which cause quite potent short-term immunosuppression, I think it should be business, or decision-making, as usual taking into account the caveats above with a major emphasis on reducing the risk of our patients acquiring the infection in the first place. 

Groupthink and knee jerk responses are not necessarily in the best interests of our patients. So after discussing the evidence with many of my patients yesterday, we are cautiously going to continue ocrelizumab and cladribine dosing. In other words, personalised decision-making and a pragmatic approach are required. What is decided for one patient may not necessarily be right for another patient; do you agree with me? 

Disclaimer: Please note this post, as with all of my blog posts, represents my personal opinions and not the views of my colleagues at Barts-MS.

CoI: multiple

#COVIDMS Will COVID-19 mutate?

Human coronaviruses are predominantly associated with respiratory tract infections. This group of viruses includes viruses that cause severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and now the COVID-19 pandemic.

One human coronavirus HCoV-OC43 is generally associated with mild upper respiratory tract infections, although it has been shown to have neuroinvasive properties. Studies in mice have shown that HCoV-OC43 can infect neurons and cause encephalitis and has also been shown to cause persistent infections in human neural-cell lines.

There are case reports that have identified HCoV-OC43 RNA in the cerebrospinal fluid or brain of children with acute disseminated encephalomyelitis and acute encephalomyelitis (see below).

Why are these observations important? They are important because it suggests that coronaviruses are potentially neurotropic and hence can infect the central nervous system. As coronaviruses are RNA viruses they have low fidelity, i.e. their reproduction results in many variants or mutations. The so-called wild-type strain tends to mutate very rapidly and hence may produce neurotropic strains quite quickly. The latter is particularly important in the context of natalizumab and potentially fingolimod and other S1P modulators.

As natalizumab blocks immune surveillance of the CNS, a person on natalizumab who develops a COVID-19 encephalitis would be in danger of major complications of the infection and possibly succumbing to the infection. The latter is analogous to PML, which is also viral encephalitis, and herpes-simplex and varicella -zoster encephalitis and CMV retinitis that have all been described in people with MS on natalizumab. 

The reason why these complications happen on natalizumab is that natalizumab blocks trafficking of anti-viral lymphocytes into the central nervous system and so if a virus gets into the CNS it will cause damage unchecked by the immune system. The EMA’s summary of product characteristics (SmPC) for natalizumab is very clear on this issue:

Infections including other opportunistic infections 

TYSABRI increases the risk of developing encephalitis and meningitis caused by herpes simplex and varicella zoster viruses. Serious, life-threatening, and sometimes fatal cases have been reported in the postmarketing setting in multiple sclerosis patients receiving TYSABRI (see section 4.8). If herpes encephalitis or meningitis occurs, the medicinal product should be discontinued, and appropriate treatment for herpes encephalitis or meningitis should be administered. Acute retinal necrosis (ARN) is a rare fulminant viral infection of the retina caused by the family of herpes viruses (e.g. varicella zoster). ARN has been observed in patients being administered TYSABRI and can be potentially blinding. Patients presenting with eye symptoms such as decreased visual acuity, redness and painful eye should be referred for retinal screening for ARN. Following clinical diagnosis of ARN, discontinuation of TYSBABRI should be considered in these patients. Prescribers should be aware of the possibility that other opportunistic infections may occur during TYSABRI therapy and should include them in the differential diagnosis of infections that occur in TYSABRI-treated patients. If an opportunistic infection is suspected, dosing with TYSABRI is to be suspended until such infections can be excluded through further evaluations.

What to do about this knowledge in the current COVID-19 pandemic is very difficult. Professor Julian Gold, an HIV and infectious disease consultant in our group, is adamant that we need to relay this information to our patients and let them make the decision if they want to stop natalizumab or fingolimod. However, as stopping these agents can result in rebound MS disease activity it would be advisable for these patients to switch to an alternative or safer DMT, i.e. interferon-beta, glatiramer acetate or teriflunomide. Professor Gold favours interferon-beta or teriflunomide as they have been shown to have antiviral effects. 

As there is no consensus on this I am doing a survey via the MS Academy to find out what the wider MS community of HCPs feels about this and other issues. Just maybe the wisdom of the crowd will be better than an individual or small group opinion. 

In the event of widespread COVID-19 epidemic, the logistics of derisking natalizumab and fingolimod is this way may not be feasible. A better way of managing this problem is reverse quarantine, i.e. at-risk patients stay on natalizumab or fingolimod and self-isolate at home to prevent themselves from becoming infected with the virus. 

The other issue I have already raised is when a vaccine emerges for COVID-19 pwMS may want to be on a DMTs that allows to receive the vaccine and mount a good response to the vaccine. Some DMTs blunt the vaccine responses.

I hope you appreciate that formulating advice when there is no evidence base is not easy. At the moment whilst the epidemic has yet to show its true extent in the UK I would advise MS patients on natalizumab or fingolimod to continue with treatment for now but to be extra-vigilant about hygiene measures. This advice may change or it may need to be personalised.

Finally, as soon as the ABN and MS Academy produce consensus guidelines I will post them on the blog. The problem about consensus is that it is often a compromise and in the absence of data may not be the best advice.

Yeh et al. Detection of Coronavirus in the Central Nervous System of a Child With Acute Disseminated Encephalomyelitis. Pediatrics January 2004, 113 (1) e73-e76.

We present a case in which human coronavirus was detected in the cerebrospinal fluid of a child presumed to have acute disseminated encephalomyelitis. In murine models, coronavirus has been found to cause a chronic demyelinating condition that resembles multiple sclerosis. Additionally, there is in vitro evidence of human coronavirus’s ability to infect neural cells. This case report provides additional support for the hypothesis that coronavirus may be an important etiologic factor in the pathogenesis of demyelinating disease in humans.

Morfopoulou et al. Human Coronavirus OC43 Associated with Fatal Encephalitis. N Engl J Med 2016; 375:497-498.

Excerpts:

….. Here we report the use of deep sequencing of a brain biopsy sample obtained from an 11-month-old boy with severe combined immunodeficiency who had symptoms of viral encephalitis with negative results on conventional diagnostic polymerase-chain-reaction (PCR) assay. 

….. The boy underwent unconditioned cord-blood transplantation, which resulted in T-cell engraftment. Nonetheless, his condition continued to deteriorate, and he died 1.5 months after receiving the transplant. RNA sequencing of a brain biopsy sample obtained 2 months after the onset of symptoms showed the presence of human coronavirus OC43 (HCoV-OC43), which was subsequently confirmed on real-time PCR (threshold cycle, 24) and brain immunohistochemical analysis. 

CoI: multiple

N.B. MOUSEDOC HERE So AS YOU KNOW THERE ARE ALREADY MUTATIONS IN THIS VIRUS THE ORIGINAL S VARIANTAND THE L VARIANT

#COVIDMS The Italians step-up to take action over COVID-19

As you are aware Northern Italy is one of the European epicentres of the coronavirus / COVID-19 pandemic. To address the concerns of MS healthcare professionals the Milan group have produced guidelines for managing DMTs in their patients. Fortunately, we have a large number of Italians in our group (‘The Blizard Little Italy’) who, with Dr Saul Reyes (ECTRIMS Fellow), helped translated the guidelines for us.

Italian recommendations on the management of MS patients during the COVID-19 epidemics

These are recommendations made by Neurologists and Infectious diseases specialists whilst we have no evidence-based data at present. 

Treatment of MS patients

Given the lack of knowledge or data on the COVID-19 disease course in MS patients receiving DMTs, at present there is no recommendation to stop the different DMTs and therefore expose MS patients to the risk of MS exacerbations. We, therefore, recommend continuing the current DMT specifically with: 

1. First-line DMTs (Beta-interferons, Glatiramer acetate, Teriflunomide or Dimethyl fumarate). These DMTs can be prescribed as usual.

2. Fingolimod. 

3. Natalizumab.
 
For ‘lymphodepleting’ DMTs: Any decisions about these DMTS should be made based on individual circumstances. 

Temporarily delay the start of lymphodepleting DMTs such as Ocrelizumab, Alemtuzumab, Rituximab or Cladribine. 

Temporarily delay (between 6 and 12 months depending on the DMT) re-dosing of Alemtuzumab, Ocrelizumab and Cladribine. This decision should be made based on individual factors such as disease severity and disease activity.

For anti-CD2O DMTs it is recommended to delay next dose even beyond 6 months if CD19+ and CD20+ lymphocyte counts are severely decreased at the time the next dose is due. 

Some special considerations: for patients who have already received the first dose of the first cycle, it is recommended to give the second dose (i.e. complete the first cycle) and ‘extra precautions’ should be taken. 

Patients with confirmed COVID-19 infection: Withheld any first or second-line DMT until clinical resolution and/or approval to continue treatment by an infectious diseases specialist (given the potential antiviral activity of beta-interferons documented in the literature, for patients receiving treatment with beta-interferons the decision about continuing treatment resides on the treating neurologist). 

Symptoms of potential COVID-19 infection: fever, dry cough and asthenia. 

What to do in the event of COVID-19 symptoms?
Instruct your patients no to attend A&E services to avoid overcrowding them and further spreading of the virus. Instruct your patients to call the local emergency number, describe their symptoms and wait for instructions. 

Evaluate the temporary withdrawal of current DMT based on the guideline provided above.  

Recommendations for MS patients and healthcare professionals at MS centres:

If possible, avoid crowded places such as cinemas, theatres, schools, etc. 

In high risk, areas restrict access to MS centres to MS patients only. 

For patients on immunosuppressive infusion therapies, the use of protective surgical-grade masks is recommended. 

If travelling long distances or using public transport is absolutely necessary, it is recommended the use of protective masks and hand sanitizing (particularly for patients on Fingolimod, Alemtuzumab, Ocrelizumab, Cladribine or Rituximab).

If possible, work from home. 

Good personal hygiene is always important, specifically, it is recommended to wash your hands frequently. These recommendations are provided as a guideline only, please always refer to your local government advice.

These recommendations are likely to change depending on the evolution of the epidemics. 

CoI: multiple

#COVIDMS COVID-19 and DMTs

The coronavirus/COVID-19 pandemic is getting people with MS (pwMS) who are on a DMT to rightly question whether or not their immune systems are competent to deal with a COVID-19 infection. Unless you are on interferon-beta, glatiramer acetate or teriflunomide, the so-called immunomodulatory therapies, your immune systems are likely to be compromised and hence you are at risk of getting more severe COVID-19 infection or secondary complications of an infection. 

Based on the immunological principles that antiviral responses are mainly driven by T-cells and natural-killer cells and less so, at least initially, by B-cells there is a hierarchy of immunosuppression on the DMTs. At the top of the list must be the immune reconstitution therapies during the depletion phase fo the treatment, i.e. HSCT, alemtuzumab [Lemtrada] and cladribine [Mavenclad]. For the maintenance treatments, I would rank them in descending order as being natalizumab [Tysabri], S1P modulators (fingolimod [Gilenya] / siponimod [Mazent] / ozanimod / ponisemod), anti-CD20 (ocrelizumab [Ocrevus] / rituximab / ofatumumab / ublituximab) and in the rear the fumaric acid esters (DMF [Tecfidera] / diroximel fumarate [Vumerity]). With the fumaric acid esters, this low ranking will not apply applies if your lymphocyte counts are low, i.e. generally lower than 0.8×109/L or 800/mm3. 

I have put natalizumab at the top of the list as we don’t know how neurotropic this virus is. If it is neurotropic, i.e. has the ability to infect the brain natalizumab is risky. Natalizumab creates a compartment that is protected from the immune system and hence puts people at risk of COVID-19 encephalitis.

Because of the coronavirus/COVID-19 pandemic should I stop my DMT? No, you should not. My advice is for you to discuss this with your HCP. There are many factors that need to be taken into account, in particular, the risk of you being exposed to COVID-19 in your country. The risk can be mitigated by hygiene measures and avoiding high-risk travel and places and contacts that may expose you to the virus. The latter strategy will become more difficult as the pandemic spreads and more people in the general population become infected and shed the virus. 

Just stopping MS DMTs, particularly natalizumab and S1P modulators, could result in MS rebound disease activity that is potentially serious. 

Because of the coronavirus/COVID-19 pandemic should I delay further infusions with natalizumab and ocrelizumab? No, you should not make this decision yourself. My advice is for you to discuss this with your HCP. If you are going to stop natalizumab you need to transition yourself onto another DMT. Ocrelizumab and the other anti-CD20 therapies are slightly different in that their treatment effect takes many months and possibly years to wear off so you have more time to think.

As I am about to start cladribine, fingolimod, siponimod, alemtuzumab, natalizumab or ocrelizumab, should I delay treatment? This will need to be discussed with your HCP and the advice will depend on the state of the COVID-19 epidemic in your country or area. For example, if you live in Milan the advice is not to start these treatments. I suspect the COVID-19 epidemic may trigger a large number of pwMS who have yet to start treatment to reconsider their choice of DMT, based on the potential risks of getting a more severe infection on immunosuppressive therapies.

I have been treated with an IRT several years ago am I at risk of infection with coronavirus/COVID-19? Yes, you are. The risk of becoming infected will be no different from that in the general population. 

The advantage of the so-called IRTs (HSCT, alemtuzumab and cladribine) is that they allow immune reconstitution, which refers to the restoring of your immune system to a state of competency after a cycle, or cycles, of depletion. Immune competence in the context of an IRT refers to the ability of the immune system to respond to infections, in particular opportunistic infections, mount an antibody response to vaccines and tumour surveillance. This has been best shown in the context of hematopoietic stem cell transplantation (HSCT) but is likely to be the case for alemtuzumab and cladribine. Please note reconstitution takes years, so if your last course was in the last 12-24 months you may still be immunocompromised. You can get a rough idea of the state of your immune system by looking at your total lymphocyte count, ideally, you want this to be above 1.0 x 109/L or 1000/mm3. 

Should I switch my DMT to interferon-beta, glatiramer acetate of teriflunomide? This may seem like a logical thing to do, but it is seldom that simple. Most pwMS are on a higher efficacy DMT because they have failed these treatments in the past. Therefore de-escalating your therapy to a previous DMT you have failed may result in your MS getting worse. 

Teriflunomide is an interesting option because it has been shown to have broad antiviral activity and hence has the potential to protect pwMS against COVID-19 infection and its complications. I would propose Sanofi-Genzyme doing urgent studies to test this hypothesis. The Coronavirus pandemic will take months to years to play out and knowing that teriflunomide has anti-coronavirus activity will be useful information for the MS community. 

In summary, there are no easy answers. The pandemic is evolving at a rapid rate and country-specific information will emerge depending on the state of the epidemic in each country. At the same time, there are many anti-viral studies been run and there is a race on to develop a vaccine. My money would be on a DNA-vaccine winning the race, because of the ease of production of these sorts of vaccines. But as always there will be regulatory hurdles to overcome and hence any vaccine studies will be months away.  So don’t rely on there being a vaccine or effective anti-viral drug anytime soon.

Hill-Cawthorne et al. Long Term Lymphocyte Reconstitution After Alemtuzumab Treatment of Multiple Sclerosis. J Neurol Neurosurg Psychiatry, 83 (3), 298-304 Mar 2012.

Background: Alemtuzumab is a lymphocyte depleting monoclonal antibody that has demonstrated superior efficacy over interferon β-1a for relapsing-remitting multiple sclerosis (MS), and is currently under investigation in phase 3 trials. One unresolved issue is the duration and significance of the lymphopenia induced. The long term effects on lymphocyte reconstitution of a single course, and the consequences that this has on disability, morbidity, mortality and autoimmunity, were examined.

Methods: The lymphocyte reconstitution (n=36; 384 person-years) and crude safety data (n=37; 447 person years) are reported for the first patients with progressive MS to receive alemtuzumab (1991-1997). Reconstitution time was expressed as a geometric mean or, when a non-negligible number of individuals failed to recover, as a median using survival analysis.

Results: Geometric mean recovery time (GMRT) of total lymphocyte counts to the lower limit of the normal range (LLN; ≥1.0×10(9) cells/l) was 12.7 months (95% CI 8.8 to 18.2 months). For B cells, GMRT to LLN (≥0.1×10(9)/l) was 7.1 months (95% CI 5.3 to 9.5); median recovery times for CD8 (LLN ≥0.2×10(9) cells/l) and CD4 lymphocytes (LLN ≥0.4×10(9) cells/l) were 20 months and 35 months, respectively. However, CD8 and CD4 counts recovered to baseline levels in only 30% and 21% of patients, respectively. No infective safety concerns arose during 447 person-years of follow-up.

Conclusions: Lymphocyte counts recovered to LLN after a single course of alemtuzumab in approximately 8 months (B cells) and 3 years (T cell subsets), but usually did not recover to baseline values. However, this long-lasting lymphopenia in patients with a previously normal immune system was not associated with an increased risk of serious opportunistic infection.

CoI: multiple

#COVIDMS COVID-19 pandemic changes the rules

I am at an MS meeting in Frankfurt and was speaking to an Italian neurologist about the COVID-19 or coronavirus pandemic and he informs me that in Milan, the epicentre of the Italian outbreak, they have stopped dosing their MS patients with ocrelizumab, alemtuzumab and cladribine until the epidemic has passed.

Interestingly, they are not stopping fingolimod, which leaves a whole cohort of pwMS at high risk of complications from COVID-19 if they get infected. As I have said in a previous post that the risk of complications from COVID-19 is likely to be higher on natalizumab as well; natalizumab blocks trafficking of lymphocytes into the CNS and gut. These compartments may allow the virus to escape the immune system and cause damage or prolong the infection.

In my post from two days ago, I added a postscript that predicted the Italian response to the virus, i.e. once COVID-19 becomes established in the community and person-to-person spread becomes more common and the source of infection(s) can’t be traced, which is happening in Italy, the public health advice will change. In this situation reverse quarantine becomes necessary, i.e. high-risk individuals need to take extra precautions, potentially self-isolating themselves so as not expose themselves to the virus. Not dosing certain DMTs, and stopping other DMTs, is part of this containment strategy.

Please note this is not necessary in the UK as all the cases have been linked to a clearly identifiable source.

John Hopkins CSSE

John Hopkins has put together a very useful website to track the pandemic in real-time. You may want to refer to this for up to date information on what is happening in your country.

The reality of the situation is a known unknown; it is only a matter of time before someone with MS, who is immunosuppressed, will be infected and succumb to the infection. It is the MS community’s responsibility to try and prevent this from happening.

CoI: multiple

#COVIDMS Coronavirus creates an opportunity for teriflunomide

Should I switch to teriflunomide? 

Please don’t panic! The coronavirus or COVID-19 pandemic is a problem but needs a calm and considered public health approach, which is happening in the UK. At the moment the general public, including pwMS, are overreacting.

Another patient emailed me yesterday to inform me they are going to stop their ocrelizumab and asked what the consequences will be. In the short-term very little, but if you decide to stop ocrelizumab it may provide an opportunity to test a hypothesis.

The treatment effect of ocrelizumab lasts many months and probably years after stopping the treatment. In the phase 2 ocrelizumab extension study, the group of patients who had been treated with ocrelizumab had no disease activity 18 months later. The latter is what underpins one of our proposed treatment arms in the ADIOS study and suggests that anti-CD20 could be used in a similar way to IRTs (immune reconstitution therapies), i.e. alemtuzumab, cladribine and HSCT. 

What about safety? B-cells and b-cell responses don’t return immediately after stopping ocrelizumab. They take about 6-12 months to reconstitute. The B-cells that return are not memory B-cells, but initially naive cells that later mature with memory B-cells taking several years to reappear. The bigger issue is circulating immunoglobulin levels. With time as more patients develop hypogammaglobulinaemia on anti-CD20 therapies, the serious infection risk will go up. This is clearly seen in the Swedish rituximab data (see below), which shows that by 6 years approximately 50% of rituximab-treated patients have had a serious infection. This will almost certainly occur with ocrelizumab and ofatumumab and the other emerging anti-CD20 therapies. 

Figure from Luna et al. 2019

Therefore stopping ocrelizumab, rituximab, ofatumumab or another anti-CD20 is not going to reverse your immune defects overnight; it will take months and possibly years to have a fully functional and reactive B-cell and plasma cell repertoire. Some argue that you can reverse these defects with immunoglobulin replacement therapy. Yes and no! Yes, in terms of broad-spectrum population-type immunity, but no in terms of antibodies against new infectious agents such as COVID-19. For the latter to be covered you would need immunoglobulin from COVID-19 exposed survivors. I suspect Chinese medical entrepreneurs will be working on this strategy already. Organism-specific, in this case, COVI-19 specific, hyperimmune globulin therapy is a well-trodden path and may yet prove to be an effective treatment strategy in managing high-risk COVID-19 infected patients as an emergency.

The latter may be relevant in the context of COVID-19 as the pandemic will play out over months to years. Similarly, if a COVID-19 vaccine is developed you may want to be in a position to maximise your benefit from any future vaccine by not being on an anti-CD20 or other immunosuppressive therapy.

What should you do if you want to derisk your immunosuppression, increase your vaccine responsiveness and keep your MS in remission? This is where the immunomodulators will see a resurgence, in particular teriflunomide. I have hypothesised in the past that teriflunomide is the ideal maintenance therapy post-induction with an anti-CD20; I called this the iTeri study. My grant application for the iTeri study was rejected by Genzyme-Sanofi; I suspect because the patent-life of teriflunomide was too short to make this study worthwhile. However, the iTeri data may emerge spontaneously from real-life data as a result of the COVID-19 pandemic. Let’s say 5,000-10,000 pwMS derisk their treatment from an anti-CD20 onto teriflunomide the data will emerge from registers on how good teriflunomide in keeping these people in remission. 

Please be aware that I have always referred to teriflunomide as the dark horse DMT; COVID-19 may prove to be the stimulus that allows teriflunomide to run free outside its small paddock.

Gustavo Luna et al.  Infection Risks Among Patients With Multiple Sclerosis Treated With Fingolimod, Natalizumab, Rituximab, and Injectable Therapies. JAMA Neurol 2019; Oct 17 (online)

Importance: Although highly effective disease-modifying therapies for multiple sclerosis (MS) have been associated with an increased risk of infections vs injectable therapies interferon beta and glatiramer acetate (GA), the magnitude of potential risk increase is not well established in real-world populations. Even less is known about infection risk associated with rituximab, which is extensively used off-label to treat MS in Sweden.

Objective: To examine the risk of serious infections associated with disease-modifying treatments for MS.

Design, setting, and participants: This nationwide register-based cohort study was conducted in Sweden from January 1, 2011, to December 31, 2017. National registers with prospective data collection from the public health care system were used. All Swedish patients with relapsing-remitting MS whose data were recorded in the Swedish MS register as initiating treatment with rituximab, natalizumab, fingolimod, or interferon beta and GA and an age-matched and sex-matched general population comparator cohort were included.

Exposures: Treatment with rituximab, natalizumab, fingolimod, and interferon-beta and GA.

Main outcomes and measures: Serious infections were defined as all infections resulting in hospitalization. Additional outcomes included outpatient treatment with antibiotic or herpes antiviral medications. Adjusted hazard ratios (HRs) were estimated in Cox regressions.

Results: A total of 6421 patients (3260 taking rituximab, 1588 taking natalizumab, 1535 taking fingolimod, and 2217 taking interferon beta/GA) were included, plus a comparator cohort of 42 645 individuals. Among 6421 patients with 8600 treatment episodes, the mean (SD) age at treatment start ranged from 35.0 (10.1) years to 40.4 (10.6) years; 6186 patients were female. The crude rate of infections was higher in patients with MS taking interferon beta and GA than the general population (incidence rate, 8.9 [95% CI, 6.4-12.1] vs 5.2 [95% CI, 4.8-5.5] per 1000 person-years), and higher still in patients taking fingolimod (incidence rate, 14.3 [95% CI, 10.8-18.5] per 1000 person-years), natalizumab (incidence rate, 11.4 [95% CI, 8.3-15.3] per 1000 person-years), and rituximab (incidence rate, 19.7 [95% CI, 16.4-23.5] per 1000 person-years). After confounder adjustment, the rate remained significantly higher for rituximab (HR, 1.70 [95% CI, 1.11-2.61]) but not fingolimod (HR, 1.30 [95% CI, 0.84-2.03]) or natalizumab (HR, 1.12 [95% CI, 0.71-1.77]) compared with interferon beta and GA. In contrast, use of herpes antiviral drugs during rituximab treatment was similar to that of interferon beta and GA and lower than that of natalizumab (HR, 1.82 [1.34-2.46]) and fingolimod (HR, 1.71 [95% CI, 1.27-2.32]).

Conclusions and relevance: Patients with MS are at a generally increased risk of infections, and this differs by treatment. The rate of infections was lowest with interferon beta and GA; among newer treatments, off-label use of rituximab was associated with the highest rate of serious infections. The different risk profiles should inform the risk-benefit assessments of these treatments.

CoI: multiple

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