Prof G's MS Blog Archive

General Disclaimer: Please note that the opinions expressed here are those of Professor Giovannoni and do not necessarily reflect the positions of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust and are not meant to be interpreted as personal clinical advice.

Clash of the Titans: the HILO study

Barts-MS rose-tinted-odometer: ★★★ (I am seeing blue and Spanish yellow today)
Roche blue (#0066CC) & Novartis Spanish Yellow (#F7B516)

Yes, I really do think that intrathecal (within the meninges that cover the brain and spinal cord) or CNS resident B-cells and plasma cells are pathogenic in MS. In other words, the cytokine or chemicals B-cells and plasma cells produce, in particular their antibodies, are what is driving some of the pathologies of smouldering MS. The evidence to support this hypothesis is well rehearsed on this blog and is the reason why we are testing high-dose ocrelizumab (more CNS penetrant) vs. standard-dose ocrelizumab (less CNS penetrant) against each other in two head-2-head studies. It is also the reason we are testing cladribine’s (CLADRIPLAS and CLAD-B) and ixazomib’s (SIZOMUS) effects in intrathecal B and plasma cell markers. Yes, I really do think we need to scrub the CNS clean of B-cells, plasma cells and their products, in particular the oligoclonal IgG bands.

I am therefore proposing a new study; the HIgh-dose versus LOw-dose anti-CD20 study or HILO Study.

In this study, I propose testing high-dose or double-dose ocrelizumab vs. standard or intermediate-dose ocrelizumab vs. low-dose ofatumumab against each other over two years and measure their impact on end-organ damage markers (slowly expanding lesions and brain volume loss) and on CSF markers of B-cell, plasma cell and microglial activity. The latter will include free kappa and lambda immunoglobulin light chains, OCBs, soluble CD14, etc. This will answer at least from a biomarker question whether or not we need CNS penetration of anti-CD20 monoclonal antibodies to target this component of smouldering MS. The following would also answer the question of whether or not you as a person with MS would want to be treated with high-dose or low-dose anti-CD20 therapy?

Would you want to be randomised into this study?

This study would be a clash of the titans; Roche vs. Novartis. Who would win? It really is not that important as Novartis is a major shareholder in Roche and hence when Roche makes a profit so does Novartis. The real winners will be people with MS, the data will allow them to make an informed decision about whether or not they want to go beyond NEIDA (no evident inflammatory disease activity) and be on a treatment that tackles the smouldering B-cell and plasma-cell driven processes within their brains and spinal cords.

SHOULD WE DO THE HILO STUDY?

Smouldering MS – not all bad news

Barts-MS rose-tinted-odometer: ★★★★★ (today’s colour is Delta Red Iron Oxide #9b2f1c)

One of the smouldering MS dogmas that have entered the MS lexicon is that the iron-rimmed slowly expanding MS lesions (SELs) go on enlarging and destroying or shredding the brain tissue around it forever. Another dogma states these SELs don’t respond to current DMTs. The good news is that both of these statements are probably incorrect.

In the recently published longitudinal MRI study below iron rims around lesions gradually diminished with time. However, having these iron rim lesions is not good news in that they are significantly more destructive than non-iron rimmed MS lesions. The question I have is what drives these lesions to form? Knowing the answer to this question will tell us what is causing MS.

The second study below demonstrates that ocrelizumab significantly reduces the expansion of slowly expanding/evolving lesions. This suggests that these lesions may be driven by intrathecal or CNS-derived immunoglobulins. This is why we are doing the high-dose ocrelizumab, SIZOMUS (ixazomib) and CHARIOT-MS (cladribine) studies to see if reducing intrathecal B and plasma cell activity has an impact on smouldering MS.

If the former studies are positive, who would want to go onto a lower-dose anti-CD20 therapy (standard-dose ocrelizumab, ofatumumab, rituximab, ublituximab)? Please note that although these lower dose anti-CD20 therapies are very effective at stopping relapses and focal MRI activity this is not MS. The real MS is smouldering MS and what we see with end-organ damage markers. This is why if I had MS I would choose a DMT that offered the best chance of normalising my brain volume loss and I would volunteer for the SIZOMUS trial.

The good news is that these two studies below show that the so-called chronic active lesions or SELs evolve over many years after their initial formation and that they may be modifiable with DMTs. Let’s celebrate these facts.

Iron-rimmed lesion of SEL expanding over 7 years; image from BRAIN.

Dal-Bianco et al. Long-term evolution of multiple sclerosis iron rim lesions in 7 T MRI. Brain. 2021 Apr 12;144(3):833-847.

Recent data suggest that multiple sclerosis white matter lesions surrounded by a rim of iron containing microglia, termed iron rim lesions, signify patients with more severe disease course and a propensity to develop progressive multiple sclerosis. So far, however, little is known regarding the dynamics of iron rim lesions over long-time follow-up. In a prospective longitudinal cohort study in 33 patients (17 females; 30 relapsing-remitting, three secondary progressive multiple sclerosis; median age 36.6 years (18.6-62.6), we characterized the evolution of iron rim lesions by MRI at 7 T with annual scanning. The longest follow-up was 7 years in a subgroup of eight patients. Median and mean observation periods were 1 (0-7) and 2.9 (±2.6) years, respectively. Images were acquired using a fluid-attenuated inversion recovery sequence fused with iron-sensitive MRI phase data, termed FLAIR-SWI, as well as a magnetization prepared two rapid acquisition gradient echoes, termed MP2RAGE. Volumes and T1 relaxation times of lesions with and without iron rims were assessed by manual segmentation. The pathological substrates of periplaque signal changes outside the iron rims were corroborated by targeted histological analysis on 17 post-mortem cases (10 females; two relapsing-remitting, 13 secondary progressive and two primary progressive multiple sclerosis; median age 66 years (34-88), four of them with available post-mortem 7 T MRI data. We observed 16 nascent iron rim lesions, which mainly formed in relapsing-remitting multiple sclerosis. Iron rim lesion fraction was significantly higher in relapsing-remitting than progressive disease (17.8 versus 7.2%; P < 0.001). In secondary progressive multiple sclerosis only, iron rim lesions showed significantly different volume dynamics (P < 0.034) compared with non-rim lesions, which significantly shrank with time in both relapsing-remitting (P < 0.001) and secondary progressive multiple sclerosis (P < 0.004). The iron rims themselves gradually diminished with time (P < 0.008). Compared with relapsing-remitting multiple sclerosis, iron rim lesions in secondary progressive multiple sclerosis were significantly more destructive than non-iron rim lesions (P < 0.001), reflected by prolonged lesional T1 relaxation times and by progressively increasing changes ascribed to secondary axonal degeneration in the periplaque white matter. Our study for the first time shows that chronic active lesions in multiple sclerosis patients evolve over many years after their initial formation. The dynamics of iron rim lesions thus provide one explanation for progressive brain damage and disability accrual in patients. Their systematic recording might become useful as a tool for predicting disease progression and monitoring treatment in progressive multiple sclerosis.

Ocrelizumab reduces the increase in the volume of SELs compared to placebo; image from BRAIN.

Elliott et al. Chronic white matter lesion activity predicts clinical progression in primary progressive multiple sclerosis. Brain. 2019 Sep 1;142(9):2787-2799.

Chronic active and slowly expanding lesions with smouldering inflammation are neuropathological correlates of progressive multiple sclerosis pathology. T1 hypointense volume and signal intensity on T1-weighted MRI reflect brain tissue damage that may develop within newly formed acute focal inflammatory lesions or in chronic pre-existing lesions without signs of acute inflammation. Using a recently developed method to identify slowly expanding/evolving lesions in vivo from longitudinal conventional T2- and T1-weighted brain MRI scans, we measured the relative amount of chronic lesion activity as measured by change in T1 volume and intensity within slowly expanding/evolving lesions and non-slowly expanding/evolving lesion areas of baseline pre-existing T2 lesions, and assessed the effect of ocrelizumab on this outcome in patients with primary progressive multiple sclerosis participating in the phase III, randomized, placebo-controlled, double-blind ORATORIO study (n = 732, NCT01194570). We also assessed the predictive value of T1-weighted measures of chronic lesion activity for clinical multiple sclerosis progression as reflected by a composite disability measure including the Expanded Disability Status Scale, Timed 25-Foot Walk and 9-Hole Peg Test. We observed in this clinical trial population that most of total brain non-enhancing T1 hypointense lesion volume accumulation was derived from chronic lesion activity within pre-existing T2 lesions rather than new T2 lesion formation. There was a larger decrease in mean normalized T1 signal intensity and greater relative accumulation of T1 hypointense volume in slowly expanding/evolving lesions compared with non-slowly expanding/evolving lesions. Chronic white matter lesion activity measured by longitudinal T1 hypointense lesion volume accumulation in slowly expanding/evolving lesions and in non-slowly expanding/evolving lesion areas of pre-existing lesions predicted subsequent composite disability progression with consistent trends on all components of the composite. In contrast, whole brain volume loss and acute lesion activity measured by longitudinal T1 hypointense lesion volume accumulation in new focal T2 lesions did not predict subsequent composite disability progression in this trial at the population level. Ocrelizumab reduced longitudinal measures of chronic lesion activity such as T1 hypointense lesion volume accumulation and mean normalized T1 signal intensity decrease both within regions of pre-existing T2 lesions identified as slowly expanding/evolving and in non-slowly expanding/evolving lesions. Using conventional brain MRI, T1-weighted intensity-based measures of chronic white matter lesion activity predict clinical progression in primary progressive multiple sclerosis and may qualify as a longitudinal in vivo neuroimaging correlate of smouldering demyelination and axonal loss in chronic active lesions due to CNS-resident inflammation and/or secondary neurodegeneration across the multiple sclerosis disease continuum.

73 tomorrow – some achievement

Barts-MS rose-tinted-odometer: ★★★★★ (Today’s colours are NHS blue & yellow #005EB8 & #FAE100)

Tomorrow the NHS turns 73. If you love the NHS and want to give it and its staff a present please have your COVID-19 vaccine. Barts Health NHS Trust and many other NHS services are running walk-in vaccine centres.

📣Roll-up, roll-up! Or should we say ‘walk-in, walk-in’! 🚶🏽 🚶🏼‍♀️ 🚶🏿‍♀️ 🚶

We’re offering Pfizer vaccine 1st doses on a walk-in basis at our centre on The Street @westfieldstrat, 8:30am–7pm.

2nd doses of the AZ vaccine are available from 8:30am–11am. @NHS_NELCCG @NHSEnglandLDN
— Barts Health (@NHSBartsHealth) July 4, 2021

https://platform.twitter.com/widgets.js

We are now in the long tail of this pandemic and the sooner we all get vaccinated the sooner the curve will flatten and the tail will get shorter.

Thank you.

To HITT or not to HITT?

Barts-MS rose-tinted-odometer: ★★★★★ (Saturday – a red-hot poker day #f54303)

There is little doubt that exercise is good for you and is a form of disease modification. However, there is a big debate about whether high-intensity interval (HIIT) or moderate continuous training (MCT) (aerobic) is best for you. This study below suggests HIIT is best.

Positive changes in cardiorespiratory fitness were larger and the non-response less with HIIT compared to MCT. Younger age and lower starting or baseline fitness predicted a higher absolute improvement following the exercise intervention.

The problem with HIIT and even MCT is that pwMS who are disabled may have difficulty exercising. Saying this, many of my patients who are even wheelchair-bound have found ways to work out using upper limb exercises. What is not addressed is how to get pwMS to start exercising; it is easy to prescribe exercise, but long term adherence with exercise and other lifestyle interventions is very poor.

If you have been successful in maintaining an exercise program can you let your fellow pwMS know your secret? Thanks.

Schlagheck et al. VO2peak Response Heterogeneity in Persons with Multiple Sclerosis: To HIIT or Not to HIIT? Int J Sports Med . 2021 Jul 1. doi: 10.1055/a-1481-8639.

Exercise is described to provoke enhancements of cardiorespiratory fitness in persons with Multiple Sclerosis (pwMS). However, a high inter-individual variability in training responses has been observed. This analysis investigates response heterogeneity in cardiorespiratory fitness following high intensity interval (HIIT) and moderate continuous training (MCT) and analyzes potential predictors of cardiorespiratory training effects in pwMS. 131 pwMS performed HIIT or MCT 3-5x/ week on a cycle ergometer for three weeks. Individual responses were classified. Finally, a multiple linear regression was conducted to examine potential associations between changes of absolute peak oxygen consumption (absolute ∆V̇O2peak/kg), training modality and participant’s characteristics. Results show a time and interaction effect for ∆V̇O2peak/kg. Absolute changes of cardiorespiratory responses were larger and the non-response proportions smaller in HIIT vs. MCT. The model accounting for 8.6% of the variance of ∆V̇O2peak/kg suggests that HIIT, younger age and lower baseline fitness predict a higher absolute ∆V̇O2peak/kg following an exercise intervention. Thus, this work implements a novel approach that investigates potential determinants of cardiorespiratory response heterogeneity within a clinical setting and analyzes a remarkable bigger sample. Further predictors need to be identified to increase the knowledge about response heterogeneity, thereby supporting the development of individualized training recommendations for pwMS.

Hey doc what’s my NFL level?

Barts-MS rose-tinted-odometer: ★★★★★ (it’s a Red & White Wednesday, as in the flag of St George, #cf2e2e)

The reason why rheumatologists are so way ahead of us in treating rheumatoid arthritis (RA) and protecting joints (the RA end-organ) is that they have an inflammatory biomarker that is closely linked to outcome, it is called the C-reactive protein (CRP), which they include as part of their treatment target. They also include a PROM (patient-related outcome measure) as part of the DAS (disease activity score); this not only involves RA patients in their treatment but gives patients with RA a deep understanding of what DMARDs (disease-modifying anti-rheumatic drugs) does to their disease.

In MS we need both a CRP and a PROM to be part of our treatment target. Do you agree?

The CRP allows rheumatologists to rapidly assess if inflammation is under control. The area under the CRP curve correlates with joint damage in the future, therefore, rheumatologists like to flatten the CRP curve. The good news is that MSologists may have the equivalent of the CRP in the form of neurofilament light chain (NFL) levels. It is quite clear that NFL is a biomarker of neuroaxonal damage in patients with active MS. Therefore it is only a matter of time before MSologsists and pwMS will want to flatten NFL curves; i.e. peripheral blood NFL levels (pbNFL) will be part of the treatment target. MS centres with the best average NFL levels in their patients will have the best outcomes.

We know that raised NFL levels are a poor prognostic sign and correlate with future MS disability and brain volume loss (end-organ damage). However, we still have several hurdles to get over before pbNFL enters routine clinical practice, but we are getting there. The other issue is setting normal levels. The great tragedy, or not, of life is that life is an age-dependent neurodegenerative disease and hence pbNFL increases with age. Therefore we are going to have to have age-dependent normative data. The paper below shows just how age-dependent pbNLF levels are.

What about a universal MS PROM? There is a big debate going on at the moment about which PROMs to collect in routine clinical practice and which ones are sensitive and reactive enough to include in an MS-DAS score. The problem for the field is when you put all the MS PROM experts in a room each has their own favourite PROM and it is virtually impossible to get a consensus on which is the best and most practical to use in routine clinical practice. Another problem is that most of the most widely used PROMs in MS are not well-liked by patients; patients feel that these PROMs don’t really capture the impact that MS is having on their lives. So I don’t think the PROM issue will be sorted anytime soon. Therefore, my money is on pbNFL levels and I have little doubt that you will be asking for and tracking your own NFL levels in the near future.

Valentino et al. Serum neurofilament light chain levels in healthy individuals: A proposal of cut-off values for use in multiple sclerosis clinical practice. Mult Scler Relat Disord. 2021 Jun 17;54:103090.

Background: Serum Neurofilament Light (sNFL) is the most promising marker for patient’s monitoring in Multiple Sclerosis (MS). However, operating reference values for use in clinical practice are still lacking. Here, we defined sNFL reference cut-off values in a cohort of healthy controls (HC) and assessed their performance in Multiple Sclerosis (MS) patients, as well as the intra-individual sNFL variability.

Methods: We measured sNFL by single molecule array (Simoa) assay in 79 HC assessing their correlation with age. Changes of sNFL levels were evaluated during a short-term follow-up (median 67 days between consecutive samples) in a subgroup of 27 participants. sNFL were tested in 23 untreated MS patients, at both diagnostic time and start of therapy (median 80 days after), considering disease activity.

Results: Findings confirmed a correlation between sNFL levels and age in HC, thus cut-off values specific for age decades were calculated. sNFL did not vary significantly with time during short-term follow-up (median CV 13%). sNFL levels in MS patients were higher and demonstrated a higher variability between diagnostic time and treatment start (median CV 39%). According to cut-off values, “pathologic” sNFL levels were found in 57% of MS patients at diagnostic time, and in 30% of samples at treatment start. In particular, “pathologic” sNFL levels were found in 80% of samples (16/20) obtained during a phase of disease activity, while a total of 85% of samples (22/26) associated with inactive disease showed sNFL in the normal range.

Conclusion: This study demonstrates an overall intra-individual stability of sNFL values in the short-term in HC and suggests age-dependent reference cut-off values that could be beneficial for sNFL implementation in clinical practice.

Laura’s story

Barts-MS rose-tinted-odometer: ★ (a very Black & Red Monday)

I received an email from Laura, a young woman with very active MS, who had been on natalizumab (Tysabri) for 7 years and had recently seroconverted to being high-index JCV seropositive. She was put onto natalizumab extended interval dosing (EID), i.e an infusion every 8 weeks, to derisk PML and to reduced the number of infusions she required during the COVID-19 pandemic. Before starting her switch therapy she was told she needed to be vaccinated with the COVID-19 vaccine. Her natalizumab was stopped and whilst she was waiting for vaccine immunity to develop she developed natalizumab-rebound. This is her story.

“I’m Laura, a pwMS in the UK and I also work in the MS field. Currently, I’m not able to work due to recent rebound disease of MS, following discontinuation of Tysabri, to switch to another DMT. I believe the decision to delay the new treatment, to try to ensure I made antibodies to the second COVID-19 vaccination, was perhaps the wrong decision to be made on my behalf (I did not have any contribution to the decision, I was informed of the decision).

To risk rebound disease is not a small matter and I would urge conversations around this prior to the switch from Natalizumab (Tysabri) or Fingolimod (Gilenya) and potentially other S1P modulators (siponimod, ozanimod and ponesimod). I was in hospital for several weeks and much more disabled than I usually am; even during a typical relapse. It was a frightening and traumatic experience, and one I thought I would never endure. My mental health has also suffered as a direct result from the rebound relapse. I’m now trying to recover at home, to increase my strength and stamina sufficiently to be able to go back to driving again, working and being a Mum to two autistic boys. Independence.

I do not know of course if I will ever go back to my previous baseline. It saddens me that this was potentially avoidable; that we need to be mindful that rebound disease, by its very definition, is more severe than what has previously been experienced, and although COVID-19 vaccination is of course very important, I would have preferred to reduce my risk of rebound disease as the priority. It is my brain and spine after all. And as we know the more lesions we acquire the less reserve we have for the future. Perhaps rebound disease should be a never event, as when managed carefully it can be avoided.”

Laura’s story is tragic and should never have happened. We know enough about natalizumab rebound to prevent it from happening. It is more likely to occur in patients who have high disease activity and a high level of disability prior to starting natalizumab (see paper below). It also occurs around month 3-4 after the last infusion of natalizumab and probably slightly earlier in patients like Laura on 8-weekly EID when the steady-state levels of natalizumab are likely to lower.

There is also no scientific evidence to suggest pwMS on natalizumab will make lower antibody responses to the COVID-19 vaccine whilst on natalizumab. In our centre, this patient will have been on 6-weekly and not 8-weekly EID. She would have had all her vaccine doses whilst on natalizumab. On the day of her last natalizumab infusion, she would have had an MRI and lumbar puncture to exclude subclinical or asymptomatic PML. Provided these were negative she would have been switched to her next DMT approximately 3-4 weeks later. If for some unforeseen reason a delay was going to occur we would have given her another infusion of natalizumab. In short, we have seen too many catastrophic rebound associated relapses and would want to prevent this from happening; we know how to prevent rebound relapses so why not?

Laura, if you are reading this blog post, thank you for agreeing to allow us to publish your story and I sincerely hope you make a good recovery from your relapse. If anything can be learnt from Laura is that please don’t let vaccine-readiness delay starting a natalizumab-switch therapy.

Laura’s case illustrates my biggest fear during COVID-19 that untreated or undertreated MS is more of a concern than COVID-19. The good news is that we should be getting a definitive answer on whether or not EID is as effective as standard interval dosing (SID) in the near future from the NOVA study (ClinicalTrials.gov Identifier: NCT03689972)

Mustonen et al. Risk factors for reactivation of clinical disease activity in multiple sclerosis after natalizumab cessation. Mult Scler Relat Disord. 2020 Feb;38:101498.

Background: Natalizumab (NTZ) is widely used for highly active relapsing-remitting multiple sclerosis (MS). Inflammatory disease activity often returns after NTZ treatment discontinuation. We aimed to identify predictive factors for such reactivation in a real-life setting.

Methods: We conducted a retrospective survey in four Finnish hospitals. A computer-based search was used to identify all patients who had received NTZ for multiple sclerosis. Patients were included if they had received at least six NTZ infusions, had discontinued treatment for at least three months, and follow-up data was available for at least 12 months after discontinuation. Altogether 89 patients were analyzed with Cox regression model to identify risk factors for reactivation, defined as having a corticosteroid-treated relapse.

Results: At 6 and 12 months after discontinuation of NTZ, a relapse was documented in 27.0% and 35.6% of patients, whereas corticosteroid-treated relapses were documented in 20.2% and 30.3% of patients, respectively. A higher number of relapses during the year prior to the introduction of NTZ was associated with a significantly higher risk for reactivation at 6 months (Hazard Ratio [HR] 1.65, p < 0.001) and at 12 months (HR 1.53, p < 0.001). Expanded Disability Status Scale (EDSS) of 5.5 or higher before NTZ initiation was associated with a higher reactivation risk at 6 months (HR 3.70, p = 0.020). Subsequent disease-modifying drugs (DMDs) failed to prevent reactivation of MS in this cohort. However, when subsequent DMDs were used, a washout time longer than 3 months was associated with a higher reactivation risk at 6 months regardless of whether patients were switched to first-line (HR 7.69, p = 0.019) or second-line therapies (HR 3.94, p = 0.035). Gender, age, time since diagnosis, and the number of NTZ infusions were not associated with an increased risk for reactivation.

Conclusion: High disease activity and a high level of disability prior to NTZ treatment seem to predict disease reactivation after treatment cessation. When switching to subsequent DMDs, the washout time should not exceed 3 months. However, subsequent DMDs failed to prevent the reactivation of MS in this cohort.

Riancho et al. Does Extended Interval Dosing Natalizumab Preserve Effectiveness in Multiple Sclerosis? A 7 Year-Retrospective Observational Study. Front Immunol. 2021 Mar 25;12:614715.

The extended interval dosing (EID) of natalizumab has been suggested to be associated with a reduced risk of progressive multifocal leukoencephalopathy (PML) and short-term preservation of efficacy but its long-term effectiveness remain unknown. We aimed to determine the long-term effectiveness and safety of natalizumab in an EID setting in a cohort of patients with multiple sclerosis (MS) treated for more than 7 years. We conducted an observational retrospective cohort study, including 39 (34 female, 5 male) patients with clinically definite relapsing-MS, initially treated with standard interval dosing (SID) of natalizumab (mean time 54 months [SD29]) who were then switched to EID, every 8 weeks (mean time 76 months [SD13]). The main outcome measures included the following: i) annualized relapse rate (ARR), ii) radiological activity, iii) disability progression, and iv) NEDA-3 no evidence of disease activity index. EID preserved ARR, radiological activity, and prevented disability worsening during follow-up. The proportion of patients maintaining their NEDA-3 status after 24, 48, and 72 months of natalizumab administration in EID was 94%, 73%, and 70%, respectively. Stratified analysis according to history of drug therapy showed that the EID of natalizumab was slightly more effective in naïve patients than in those previously treated with other immunosuppressive drugs. No cases of PML or other severe adverse reactions were reported. In conclusion, long-term therapy with natalizumab in an EID setting following an SID regimen maintained its disease-modifying activity, and was safe and well tolerated for over 7 years. These encouraging observational results need to be confirmed in controlled clinical trials.

Dysbiosis

Barts-MS rose-tinted-odometer: ★★★ (a lilac rose-tinted Sunday; and why not! #C8A2C8)

Dysbiosis refers to abnormalities in the human microbiome that affect disease and life outcomes. In the context of MS, it is claimed that changes in the gut microbiome may not only increase your risk of getting MS but act as a proinflammatory signal to drive MS disease activity and reduce remyelination and recovery. The corollary is that manipulation of your microbiome with antibiotics, faecal transplantation, probiotics and diet can be used to treat MS. Do you agree?

My problem with the field of dysbiosis is how to interpret the data. Many of the hypotheses and claims being explored are plausible, but the lack of vigour and the application of causation theory in regard to some of the claims being made is worrying. More worrying is that some quacks have already jumped on the bandwagon and have started offering faecal transplants and probiotics to treat MS.

There is little doubt that the metagenome, i.e. our genomes and the genomes of the microorganisms that inhabit our bodies, is what life is. For example, without certain bacteria in our gut, we wouldn’t be able to eat certain foodstuffs. The most quoted example is the bacteria Bacteroides plebeius that allows humans to eat and breakdown seaweed; this bacteria is found more commonly in the gut of seaweed eating populations such as the Japanese.

Trying to find the gut bacterium that causes MS or increase the chances of getting MS will be like seeking a needle in ten thousand haystacks. I have been thinking about how we tackle this problem. One way may be to look at populations that had low incidence of MS and then to follow the changes in the gut microbiota longitudinally and see if something shows up in those who develop MS. The problem with this approach is the resources, the time required and the sheer size of the study required.

What is clear is that your microbiome is very plastic and can be changed relatively easily by manipulating your diet; going from a high fibre diet to a low fibre diet or from a high carbohydrate diet to a ketogenic diet changes your microbiome within days. This is very relevant to managing some diseases, for example, ketogenic diets and their presumed effect on the microbiome increases the response rate of some cancers to certain chemotherapy regimens. The question is the metabolic hacking of ketosis or the effect of the diet on the microbiome that is responsible for the treatment effect? I suspect it is both. There is also very compelling data emerging that ketogenic diets are anti-inflammatory, which in addition to their neuroprotective effects, explains why they are being studied in MS and widely adopted by segments of the MS community. Are their other diets with as a compelling scientific rationale? Not to the best of my current knowledge.

In the context of the above, you may be interested in the animal (EAE) study below which shows a small therapeutic effect of the administration of Clostridia, a bacterium that may be beneficial in MS, as a treatment in mice induced to have experimental allergic encephalomyelitis or EAE. The treatment effect is quite modest; I doubt MD would be impressed with the size of the effect. However, the authors conclude “… gut dysbiosis in MS patients could be partially rebalanced by these commensal bacteria and their immunoregulatory properties could have a beneficial effect on MS clinical course”. Really?

The question I have for you is how many of you are using probiotic supplements, diet, etc. to specifically change your microbiomes? How have you heard about these treatments and have you noticed any impact on your MS or MS-related symptoms?

Calvo-Barreiro et al. Selected Clostridia Strains from The Human Microbiota and their Metabolite, Butyrate, Improve Experimental Autoimmune Encephalomyelitis. Neurotherapeutics (2021); Published: 07 April 2021.

Gut microbiome studies in multiple sclerosis (MS) patients are unravelling some consistent but modest patterns of gut dysbiosis. Among these, a significant decrease of Clostridia cluster IV and XIVa has been reported. In the present study, we investigated the therapeutic effect of a previously selected mixture of human gut-derived 17 Clostridia strains, which belong to Clostridia clusters IV, XIVa, and XVIII, on the clinical outcome of experimental autoimmune encephalomyelitis (EAE). The observed clinical improvement was related to lower demyelination and astrocyte reactivity as well as a tendency to lower microglia reactivity/infiltrating macrophages and axonal damage in the central nervous system (CNS), and to an enhanced immunoregulatory response of regulatory T cells in the periphery. Transcriptome studies also highlighted increased antiinflammatory responses related to interferon beta in the periphery and lower immune responses in the CNS. Since Clostridia-treated mice were found to present higher levels of the immunomodulatory short-chain fatty acid (SCFA) butyrate in the serum, we studied if this clinical effect could be reproduced by butyrate administration alone. Further EAE experiments proved its preventive but slight therapeutic impact on CNS autoimmunity. Thus, this smaller therapeutic effect highlighted that the Clostridia-induced clinical effect was not exclusively related to the SCFA and could not be reproduced by butyrate administration alone. Although it is still unknown if these Clostridia strains will have the same effect on MS patients, gut dysbiosis in MS patients could be partially rebalanced by these commensal bacteria and their immunoregulatory properties could have a beneficial effect on MS clinical course.

Do central nervous system anti-CD20 effects matter?

Barts-MS rose-tinted-odometer: ★★★ (gray Friday; overcast and miserable #3a3b3c)

It was not easy writing this blog post; I hope it makes sense. I was asked the other day ‘what defines a low versus a high-dose B-cell depleting anti-CD20 therapy?’.

Unlike with small molecules the dose of monoclonal antibodies is not necessarily about drug/antibody levels, but how much of the target gets inhibited or depleted and then how long these effects last. So when I compare ocrelizumab (600mg intravenously every 6 months) with ofatumumab (20mg subcutaneously every month) is there a difference? Yes and no; it depends on whether or not you take into account the potential CNS effects of these agents.

No in the sense that both of these doses are likely to keep circulating peripheral B-cell numbers very low and seem to have similar effects when it comes to suppression of inflammatory MS activity, i.e. relapses, focal MRI lesions, relapse associated-worsening and possibly even a component of PIRA (progression independent of relapses).

It is clear that ocrelizumab is a higher dose and is having a greater effect on deep tissue B-cells. The half-life of circulating monoclonal antibodies is partially determined by the circulating concentration vs. the quenching effect of the target antigen. The more circulating antibody around, the longer its half-life. The more target antigen around, i.e. CD20+ B-cells, the lower half-life of the antibody because the antigen binds to and removes antibody from the circulation. Following B-cell depletion, the half-life at steady state for ofatumumab is estimated to be approximately 16 days (FDA ofatumumab prescribing information) compared to 26 days for ocrelizumab (FDA ocrelizumab prescribing information).

Other differences supporting the low vs. high dose differences relate to B-cell repopulation kinetics. For ofatumumab B-cell counts reach the lower limit of normal in at least 50% of patients in 24 to 36 weeks after stopping treatment, which equates to a median time to B-cell recovery of ~40 weeks post-treatment discontinuation (FDA ofatumumab prescribing information). For ocrelizumab, the median time for B-cell counts to return to either baseline or the lower limit of normal is 72 weeks (range 27-175 weeks) (FDA ocrelizumab prescribing information).

Based on the above there is little doubt that ocrelizumab is higher-dose than ofatumumab. Is this relevant? I think it may be if part of the mode of action of B-cell depletion therapies is to target B-cells and B-cell follicle-like structures within the CNS of pwMS. The amount of antibody that crosses the blood-brain barrier is roughly 0.5% of what is circulating in the periphery; as steady-state levels are higher with ocrelizumab more of it is likely to cross the blood-brain barrier and affect CNS and meningeal B-cells.

We are only one of many groups that hypothesise that the intrathecal or CNS B-cells, plasma cells and antibodies (oligoclonal bands) are pathogenic in MS and are driving some of the smouldering pathologies we see in MS. This is why we are exploring therapies such as proteasome inhibitors (ixazomib), cladribine, BTK inhibitors and high-dose ocrelizumab to see if we can scrub the CNS clean of OCBs. So yes, based on this hypothesis I think the dose of ofatumumab may be too low to affect intrathecal B-cells. A clue to this is that there was no dose effect, based on body size, on disability progression noted with ofatumumab compared to that seen with ocrelizumab. Why?

Dose-response relationships in biology are often S-shaped. I suspect the intrathecal effects of ofatumumab based on body size is on the flat part of the S-curve. In comparison with the higher body-size based doses of ocrelizumab, the intrathecal/smouldering MS effects are on the linear part of the curve and hence why there is a clear signal (see dosing imaging below). There is a way to investigate this hypothesis involves doing detailed CSF studies comparing what happens within the spinal fluid of patients on ocrelizumab high-dose vs. ocrelizumab standard-dose vs. ofatumumab standard-dose. I hypothesize there will be a clear ladder on the impact on CNS B-cell biology. At the same time, we can ask what is the impact of this anti-CD20 dosing tier is on meningeal B-cell follicle-like structures, slowly expanding lesions, subpial cortical lesions, brain volume loss, CSF NFL levels, etc.?

So yes, I do think ofatumumab is a low-dose anti-CD20 therapy and ocrelizumab is a higher-dose anti-CD20 therapy. This explains why I helped push/nudged Roche-Genentech to design and run their own version of our proposed DoDo (double-dose) ocrelizumab study. The good news is that these high-dose ocrelizumab trials are recruiting rapidly and we should have an answer to some of these questions in the next 3-4 years.

Based on the above I am also against low-dose rituximab dosing in MS. I think we need high-dose CNS-penetrant anti-CD20 therapies; at least initially. Once you have purged the CNS of B-cells and B-cell follicle like structures the dose can probably be reduced.

Please, let me know if this post makes sense? Thanks.

CoI: Please note I sit on the steering committee of Roche-Genentech’s high-dose ocrelizumab programme.

Early cladribine treatment prevents MS

Barts-MS rose-tinted-odometer: ★★★★★★ (6-star bull’s blood red #8a0303)

Yesterday’s post on using cladribine to prevent CIS from converting to MS and whether this is MS prevention or an MS cure generated a robust debate. Good, this was the purpose of the post; i.e. to get you thinking.

As you are aware that as the diagnostic criteria for MS evolve many people diagnosed with CIS in the past actually have MS when the new diagnostic criteria are applied retrospectively. This then allows you to see how well cladribine works in preventing conversion to MS in the small subgroup of subjects who have ‘CIS’ and not MS when they were treated with cladribine.

The subjects who were still CIS after applying the newer McDonald diagnostic criteria showed that cladribine’s treatment effect improved with a reduction in risk of conversion to clinically definite MS by 63% on low-dose cladribine and by 75% on high-dose cladribine compared to placebo. I am not sure the MS community has clocked how effective cladribine really is when used early.

This post-hoc analysis also suggests that people with CIS treated with lower doses of cladribine actually do better than those on higher doses. The dose-effect is pretty clear when you look at the time to next attack or three-month confirmed disability worsening. Have we optimised the dose of cladribine? When you are trying to prevent/cure MS maybe not!

Any predictions? I predict that a proportion of patients with CIS treated early with cladribine may never go on to have a second attack or disability progression and hence are prevented from developing MS or cured of their MS, depending on how you define MS. Anyone taking bets?

Freedman et al. The efficacy of cladribine tablets in CIS patients retrospectively assigned the diagnosis of MS using modern criteria: Results from the ORACLE-MS study. Mult Scler J Exp Transl Clin. 2017 Oct 9;3(4):2055217317732802.

Background: Multiple sclerosis (MS) diagnostic criteria have changed since the ORACLE-MS study was conducted; 223 of 616 patients (36.2%) would have met the diagnosis of MS vs clinically isolated syndrome (CIS) using the newer criteria.

Objective: The objective of this paper is to assess the effect of cladribine tablets in patients with a first clinical demyelinating attack fulfilling newer criteria (McDonald 2010) for MS vs CIS.

Methods: A post hoc analysis for subgroups of patients retrospectively classified as fulfilling or not fulfilling newer criteria at the first clinical demyelinating attack was conducted.

Results: Cladribine tablets 3.5 mg/kg (n = 68) reduced the risk of next attack or three-month confirmed Expanded Disability Status Scale (EDSS) worsening by 74% vs placebo (n = 72); p = 0.0009 in patients meeting newer criteria for MS at baseline. Cladribine tablets 5.25 mg/kg (n = 83) reduced the risk of next attack or three-month confirmed EDSS worsening by 37%, but nominal significance was not reached (p = 0.14). In patients who were still CIS after applying newer criteria, cladribine tablets 3.5 mg/kg (n = 138) reduced the risk of conversion to clinically definite multiple sclerosis (CDMS) by 63% vs placebo (n = 134); p = 0.0003. Cladribine tablets 5.25 mg/kg (n = 121) reduced the risk of conversion by 75% vs placebo (n = 134); p < 0.0001.

Conclusions: Regardless of the criteria used to define CIS or MS, 3.5 mg/kg cladribine tablets are effective in patients with a first clinical demyelinating attack. ClinicalTrials.gov registration: The ORACLE-MS study (NCT00725985).