Tag: plasma cells

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? 

Conflicts of Interest

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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. 

Goalposts

We need to keep pushing the envelope and moving the goalposts in terms of our treatment targets in MS. 

As MS advances innate immune activation with microglial and astrocyte activation occurs. However, the latter may be adaptive in response to damage and hence a good thing, which is why I am sceptical about treatments aimed at targeting these cells in advanced MS. 

In comparison, B-cells and plasma cells are a different story. These cells are part of the adaptive immune system and are likely producing pathogenic, or damaging, antibodies. B cells and plasma cells set-up shop in the brain and spinal cords of MSers and churn out these heat-seeking missiles that are likely to be responsible for smouldering MS; i.e. the cortical lesions and the slowly expanding lesions or (SELs), which cause disease worsening even in those MSers who are NEDA (no relapses or no new or enhancing MRI lesions). The problem we have is that our current DMTs don’t appear to target these cells with the possible exception of cladribine that is a small molecule and gets into the brain and spinal cords of MSers.  Konrad Rejdak and colleagues in Poland have shown that about 50% of cladribine treated MSers lose their oligoclonal IgG bands (OCBs) from their CSF and that the patients who lose their OCBs tend to be stable compared to those who don’t lose their OCBs. We need to replicate these findings and supports our hypothesis to target CNS-resident plasma cells in MS.

Please note spinal fluid OCBs and immunoglobulin free light chains are at the bottom of our treat-2-target pyramid. This is our new goalposts.

This is why we are starting two studies in parallel, and want to start more studies with additional agents, to see if we can get rid of OCBs in MSers.

Our first study will look at oral cladribine’s effect on B-cell and plasma cell activity within the brain and spinal cords of MSers. Does cladribine reduce OCBs and immunoglobulin production? This study is called the “Oral Cladribine B-cell study” or CLAD B.

The following are the inclusions criteria for CLAD B:

  1. Patients with RRMS who are being treated with oral cladribine at Barts Health NHS Trust
  2. Patients must be willing and able to undergo lumbar punctures
  3. Patients who are OCB positive in their CSF (from previous diagnostic lumbar puncture) 

In our second study, we are testing a myeloma drug called Ixazomib in MS. Ixazomib is a second-generation proteasome inhibitor that works against malignant plasma cells. This study is called “Safety of targeting plasma cells in Multiple Sclerosis: A phase 1b randomised, double-blind, placebo-controlled trial” or SIZOMUS.

The following are the SIZOMUS inclusion criteria:

Each participant must meet all of the following inclusion criteria to be enrolled in the SIZOMUS study:

  1. Male and female patients 18 to 65 years old at screening.
  2. Must have a diagnosis of MS, and:
    1. Patients with RRMS must be on DMT
    2. Patients with progressive MS must not be on DMT
  3. Participants with RRMS must be on stable DMT (i.e. must not have had a relapse within 1 month prior to the screening visit)
  4. OCB positive CSF either from a previous CSF analysis or from the screening CSF analysis
  5. Patients must be willing and able to undergo lumbar punctures
  6. Agree to use of effective contraception

For those interested in proteasome inhibitors there is an emerging evidence base of them working in autoimmune diseases in general, in particular with the 1st-generation drug called Bortezomib. 

Do you think we are crazy? We have been working on getting these trials off the ground for over 3 years and the ideas, and hypotheses, underpinning these trials goes back more than 15 years. I originally wanted to do a thalidomide trial, targeting plasma cells, way back in 1997. However, I was advised against it by Professor W. Ian McDonald who thought it would be too risky. 

If you live in London, or the home counties, and are interested in participating in these trials, and you think you are eligible, let your HCP know and they can contact us.

Baker et al. Plasma cell and B cell-targeted treatments for use in advanced multiple sclerosis. Mult Scler Relat Disord. 2019 Jun 26;35:19-25

There is increasing evidence that agents that target peripheral B cells and in some instances plasma cells can exhibit marked effects on relapsing multiple sclerosis. In addition, B cells, including plasma cells, within the central nervous system compartment are likely to play an important role in disease progression in both relapsing and progressive MS. However, current B cell-targeting antibodies may not inhibit these, because of poor penetration into the central nervous system and often oligoclonal bands of immunoglobulin persist within the cerebrospinal fluid despite immunotherapy. Through targeting B cells and plasma cells in the CNS, it may be possible to obtain additional benefit above simple peripheral depletion of B cells. As such there are a number of inhibitors of B cell function and B cell depleting agents that have been developed for myeloma and B cell leukaemia and lymphoma, which could potentially be used off-label or as an experimental treatment for advanced (progressive) MS.

CoI: multiple

Beyond the B-cell

Do we have the right cell target in MS? Yes and no; we need a multicellular approach.

Recently the attention in MS has been on the B-cell as if it was the holy grail of MS treatments. It is not.

In several posts, over the last few weeks, I have made the case that the B-cell is important, probably as an antigen presenting cell, but it is not the ‘be all and end all’ of MS treatments. It is clear that rebound post-natalizumab is driven my B-cells and the positive data on the first BTK inhibitor would indicate that the B-cells are working via the B-cell receptor on antigen presentation. If only we knew what these antigens were we would have a much better handle on the cause of MS.

I know this science stuff is hard, but it is important. At the end of the day, the nut and bolts of MS must be molecular; molecules mean treatment targets and potentially more focused and hopefully better and safer treatments in the future.

I have stressed that simply targeting B-cells in both the periphery and central nervous system will not be enough to effectively treat MS in the long-term. When we look at end-organ damage markers in pwMS who are on B-cell therapies they have ongoing brain volume loss, albeit at a lower rate, and enlarging lesions (T1 black holes), which are both indicative of ongoing smouldering MS. So what do we need to do? I have provided circumstantial evidence that NIRTs (non-selective immune reconstitution therapies) have a slight edge on the B-cell therapies and this may be because they are also targeting T-cells. The latter, however, comes at a price of greater adverse events in relation to immunosuppression. The proportion of MSers on NIRTs who experience disability improvement seems higher when compared to the anti-B cell agents, which indicates that NIRTs are doing something else over and above their effect on the B-cell compartment. However, based on their overall safety profile it is unlikely that the NIRTs (alemtuzumab & HSCT) will be a therapeutic strategy that the wider MS community will adopt with vigour. Although from comments on this blog there is an informed group of MSers who feel hard done by because their HCPs won’t offer them the option of using NIRTs first-line, i.e. very early in the course of their disease when they have the most to gain from these therapies.

Is there anything else we can do to improve on the profile of B-cell therapies to make them better? Yes, I think there is. Targeting the plasma cell,in addition to the B-cell. Data on plasma cells goes back decades and surprisingly the plasma cell has never been a major therapeutic target in MS. John Prineas, one of my MS heroes, has always stressed the importance of the plasma cell in MS. His paper below from 1978 documents just how enriched the brains of MSers are with this population of cells. What is often not stressed is that the biology of plasma cells is so so different to the B-cell, which opens up new therapeutic targets that are quite different to those in the T and B cell compartments. More on this topic another time.

You are aware of the recent publication showing that about 55% of Polish MSers treated with intravenous cladribine lost their oligoclonal bands 10 or more years after treatment and if they did lose their OCBs they tended to have lower EDSS scores. We have known for years that MSers, with either relapse-onset or primary progressive diseases, who don’t have OCBs do better. There is also evidence from biomarker and pathology studies that the OCBs may be driving several of the disease processes that have been linked to advanced or progressive MS, i.e. microglial activation and grey matter pathology. Based on these observations, we hypothesise that OCBs are very likely to be pathogenic in MS, which is why we are embarking a research programme to try and target the plasma cells within the CNS of MSers. Do you think we are crazy?

To get a handle on the plasma cell we are going to have to study what happens in the spinal fluid. There are simply too many plasma cells in the periphery which will drown out any signal from the CNS. To participate in the studies we are planning we will have to perform serial, annual, lumbar punctures or spinal taps to see if our add-on therapy is killing and/or reducing the number of plasma cells in your brain and spinal cords. The good news is that we have de-risked the lumbar puncture with the use of atraumatic needles and screening. I never thought I would be saying this but most of our patients don’t mind having LPs, particularly when they understand the reason behind the LP.  CSF neurofilament levels are now part of our prognostic profile of MSers at baseline and we are increasingly using them to assess response, or lack of response, to treatment. So if you want to be treated and treated-2-target beyond NEDA, and beyond the B-cell, then having an LP is important.

We hope our proposed plasma cells studies will lead to a mindset that goes beyond the B-cell to target some of the mechanisms that are responsible for smouldering MS.

Prineas & Wright. Macrophages, lymphocytes, and plasma cells in the perivascular compartment in chronic multiple sclerosis. Lab Invest. 1978 Apr;38(4):409-21.

Perivascular cells in CNS tissue from six multiple sclerosis (MS) patients and a patient with motor neuron disease were examined by light and electron microscopy. Lymph node tissue from one MS patient was also examined. CNS perivascular macrophages in both MA and motor neuron disease were found to closely resemble free macrophages elsewhere in the body except that they often contained unusually large primary lysosomes. Cytoplasmic inclusions consisting of membrane-bound stacks of curved linear profiles, presumed to be a product of myelin degradation, were constantly observed in microglia in MS plaques but were rarely observed in perivascular macrophages in the same area. Unidentified cylindrical bodies were observed within cysternae of rough endoplasmic reticulum in some lymph node cells. Quantitative studies of the perivascular cell population in one MS case revealed, in histologically normal white matter 260 lymphocytes and 178 plasma cells per cubic millimeter of fresh tissue. Typical chronic plaque tissue without obvious inflammatory cell cuffing contained 1772 plasma cells per cubic millimeter of fresh tissue. No plasma cells were observed in the CNS in motor neuron disease. The results of this study suggest that perivascular macrophages in the CNS represent a specialized population of monocyte-derived free macrophages, that these cells differ functionally from microglial cells, and that the digestion of myelin breakdown products in MS requires the participation of both cell types. The results also suggest that in some chronic MS cases there is a large, permanent population of CNS plasma cells that persists, like the elevated cerebrospinal fluid IgG level in this disease, for the life of the patient, that these cells, rather than inflammatory cells in fresh lesions, are the major source of this raised IgG, and that the existence of such a population of cells may indicate the continuing expression of antigens in chronic MS lesions in the absence of fresh lesion formation.

Beyond NEDA

Prof G are we being lulled into a false sense of security by being told that we have no evident disease activity (NEDA)?

A patient of mine, who I have been looking after now for over 11 years, asked me in clinic a few weeks ago why despite being NEDA for 6 years, on a highly effective maintenance DMT (fingolimod), has she gone from being able to run 5-10 km to needing a stick and barely managing to walk from the Whitechapel Underground Station to my clinic (~200m), without having to stop and rest?

What this patient doesn’t know, despite no new visible T2 lesions, is that she has developed obvious, to the naked eye, progressive brain atrophy.  This particular patient prompted me to write a few blog posts to try and explain what is happening to her brain. Before reading the remainder of this post you may want to read the following posts:

An important question in relation to this patient is why do some DMTs have such a profound impact on end-organ damage markers, in particular, brain volume loss and others do not? Not all DMTs are made equal when it comes to preventing, or slowing down, brain volume loss.

At the top of the league table are alemtuzumab and HSCT (~0.2-0.25% loss per annum). Both these treatments are NIRTs (non-selective immune reconstitution therapies). Natalizumab is next with an annual brain volume loss in region of 0.25-0.30% per annum. Ocrelizumab (anti-CD20) comes fourth with a rate of brain volume loss of ~0.30-0.35% per annum. Fingolimod 5th at ~0.4% per annum. Cladribine has a rate of loss of brain volume of ~0.55% per annum with the other runs after that.

For me, the disappointment are the anti-B cell therapies, ocrelizumab and cladribine. Despite these DMTs being very effective at switching off new focal inflammatory lesions (relapses and new T2 and Gd-enhancing lesions) their impact on end-organ damage is only moderate. These observations have convinced me more than ever that focal inflammation is not MS, but simply the immune system’s response to what is causing MS. The latter hypothesis is what I have been presenting as part of my ‘Field Hypothesis’ for several years on this blog.

What these observations are telling me is that peripheral B-cells are a very important part of the immune response to the cause of MS, but they are not necessarily involved in driving the true pathology, which is causing the progressive brain volume loss. The caveat to this is that anti-CD20 therapies and cladribine may not be eliminating the B-cells and plasma cells within the CNS, which is why we need add-on treatments to try and scrub the brain free of these cells to see if the brain atrophy rate ‘normalises’. This is why we are starting a safety study this year of an add-on myeloma drug to target the CNS B-cell and plasma cell response to test this hypothesis.

What does this mean for the average person with MS? Firstly, you may not want to dismiss alemtuzumab and HSCT as a treatment option. These NIRTS differ from anti-CD20 therapies and cladribine in that they target both B and T cells. We may need to target both these cells types to really get on top of MS. I am aware of the appeal of anti-CD20 therapies and cladribine; they are safer and easier to use because of less monitoring, however, this may come at a cost in the long-term. The SIRTs (selective IRTs) may not be as good as the NEDA data suggests. Please remember that once you have lost brain you can’t get it back.

The tradeoff with alemtuzumab and HSCT is the frontloading of risk to get the greatest efficacy over time. Choosing a DMT on a rung or two down on the therapeutic ladder gives you better short-term safety and makes the lives of your MS team easier, because of less monitoring, but at a potential long-term cost to your brain and spinal cord.  This is why to make an informed decision about which DMT you choose is a very complicated process and subject to subtle and often hidden effects of cognitive biases. The one bias I am very aware of is the ‘Gambler’s Dilemma’, be careful not to be lulled into a false sense of security by your beliefs; most gamblers lose.

Over the last few years you may have seen a theme developing in my thinking as we move the goalposts in terms of our treatment target beyond NEDA-3 to target end-organ damage, i.e. brain volume loss, T1 black holes, the slowly expanding lesions (SELs), neurofilament levels, cognition, sickness behaviour, OCBs, etc. Our treatment aim should be to ‘Maximise Brain Health’ across your life and not just the next decade. Please stop and think!

When I was preparing this post I dropped Prof. Doug Arnold an email about the impact of alemtuzumab and HSCT on the slowly expanding lesion or SEL. Unfortunately, these analyses have not been done despite good trial data sets being available for analysis. He said it was a resource issue; i.e. a euphemism for money and permission to do the analyses. For me, these questions are the most important ones to answer in 2019. Wouldn’t you want to know if alemtuzumab and HSCT were able to switch off those destructive SELs in your brain? Knowing this may impact your decision to go for the most effective DMTs; frontloading risk to maximise outcomes in the long term.

What should I advise my patient; to stay on fingolimod or to escalate to a more effective DMT?

The following articles are the important ones for you to read or at least be aware of:

Article 1

Lee et al. Brain atrophy after bone marrow transplantation for treatment of multiple sclerosis. Mult Scler. 2017 Mar;23(3):420-431.

BACKGROUND:  A cohort of patients with poor-prognosis multiple sclerosis (MS) underwent chemotherapy-based immune ablation followed by immune reconstitution with an autologous hematopoietic stem cell transplant (IA/aHSCT). This eliminated new focal inflammatory activity, but resulted in early acceleration of brain atrophy.

OBJECTIVE: We modeled the time course of whole-brain volume in 19 patients to identify the baseline predictors of atrophy and to estimate the average rate of atrophy after IA/aHSCT.

METHODS: Percentage whole-brain volume changes were calculated between the baseline and follow-up magnetic resonance imaging (MRI; mean duration: 5 years). A mixed-effects model was applied using two predictors: total busulfan dose and baseline volume of T1-weighted white-matter lesions.

RESULTS: Treatment was followed by accelerated whole-brain volume loss averaging 3.3%. Both the busulfan dose and the baseline lesion volume were significant predictors. The atrophy slowed progressively over approximately 2.5 years. There was no evidence that resolution of edema contributed to volume loss. The mean rate of long-term atrophy was -0.23% per year, consistent with the rate expected from normal aging.

CONCLUSION: Following IA/aHSCT, MS patients showed accelerated whole-brain atrophy that was likely associated with treatment-related toxicity and degeneration of “committed” tissues. Atrophy eventually slowed to that expected from normal aging, suggesting that stopping inflammatory activity in MS can reduce secondary degeneration and atrophy.

Article 2

Arnold et al. Superior MRI outcomes with alemtuzumab compared with subcutaneous interferon β-1a in MS. Neurology. 2016 Oct 4;87(14):1464-1472.Neurology. 2016 Oct 4;87(14):1464-1472.

OBJECTIVE: To describe detailed MRI results from 2 head-to-head phase III trials, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis Study I (CARE-MS I; NCT00530348) and Study II (CARE-MS II; NCT00548405), of alemtuzumab vs subcutaneous interferon β-1a (SC IFN-β-1a) in patients with active relapsing-remitting multiple sclerosis (RRMS).

METHODS: The impact of alemtuzumab 12 mg vs SC IFN-β-1a 44 μg on MRI measures was evaluated in patients with RRMS who were treatment-naive (CARE-MS I) or who had an inadequate response, defined as at least one relapse, to prior therapy (CARE-MS II).

RESULTS: Both treatments prevented T2-hyperintense lesion volume increases from baseline. Alemtuzumab was more effective than SC IFN-β-1a on most lesion-based endpoints in both studies (p < 0.05), including decreased risk of new/enlarging T2 lesions over 2 years and gadolinium-enhancing lesions at year 2. Reduced risk of new T1 lesions (p < 0.0001) and gadolinium-enhancing lesion conversion to T1-hypointense black holes (p = 0.0078) were observed with alemtuzumab vs SC IFN-β-1a in CARE-MS II. Alemtuzumab slowed brain volume loss over 2 years in CARE-MS I (p < 0.0001) and II (p = 0.012) vs SC IFN-β-1a.

CONCLUSIONS: Alemtuzumab demonstrated greater efficacy than SC IFN-β-1a on MRI endpoints in active RRMS. The superiority of alemtuzumab was more prominent during the second year of both studies. These findings complement the superior clinical efficacy of alemtuzumab over SC IFN-β-1a in RRMS.

CLINICALTRIALSGOV IDENTIFIER: NCT00530348 and NCT00548405.

CLASSIFICATION OF EVIDENCE: The results reported here provide Class I evidence that, for patients with active RRMS, alemtuzumab is superior to SC IFN-β-1a on multiple MRI endpoints.

Article 3

Vavasour et al. A 24-month advanced magnetic resonance imaging study of multiple sclerosis patients treated with alemtuzumab. Mult Scler. 2018 Apr 1:1352458518770085. doi: 10.1177/1352458518770085.

BACKGROUND: Tissue damage in both multiple sclerosis (MS) lesions and normal-appearing white matter (NAWM) are important contributors to disability and progression. Specific aspects of MS pathology can be measured using advanced imaging. Alemtuzumab is a humanised monoclonal antibody targeting CD52 developed for MS treatment.

OBJECTIVE: To investigate changes over 2 years of advanced magnetic resonance (MR) metrics in lesions and NAWM of MS patients treated with alemtuzumab.

METHODS: A total of 42 relapsing-remitting alemtuzumab-treated MS subjects were scanned for 2 years at 3 T. T1 relaxation, T2relaxation, diffusion tensor, MR spectroscopy and volumetric sequences were performed. Mean T1 and myelin water fraction (MWF) were determined for stable lesions, new lesions and NAWM. Fractional anisotropy was calculated for the corpus callosum (CC) and N-acetylaspartate (NAA) concentration was determined from a large NAWM voxel. Brain parenchymal fraction (BPF), cortical thickness and CC area were also calculated.

RESULTS: No change in any MR measurement was found in lesions or NAWM over 24 months. BPF, cortical thickness and CC area all showed decreases in the first year followed by stability in the second year.

CONCLUSION: Advanced MR biomarkers of myelin (MWF) and neuron/axons (NAA) show no change in NAWM over 24 months in alemtuzumab-treated MS participants.

CoI: multiple