Curing MS

Barts-MS rose-tinted-odometer: ★★★★★

I have been asked many times if we can cure someone who has MS. I have tried to explain what an MS cure may look like many times on this blog and have actually published articles defending the definition. 

I explained in a previous post that you may be cured of your MS, but still, have worsening or progressive disease. The difference between progressive disease, which is due to previous MS damage and ageing is that the former should burn out, i.e. after a period of time, your worsening disability should eventually stop or flat-line. In comparison, MS-induced premature ageing is unlikely to stop. In comparison defining a cure in people who are young, with reserve capacity, who have been treated earlier is a much easier task. 

From a biological perspective you can be cured but still have neurological deficits from previous damage, which need to be targeted with so-called ‘repair’ and ‘neuroregenerative’ therapies. These are separate processes and are independent of a so-called biological cure. 

Based on our current understanding of MS a cure can only really occur in relation to IRTs (immune reconstitution therapies; e.g. alemtuzumab, cladribine & HSCT), i.e. treatments that are given as short courses that address the underlying ‘cause’ of MS. Maintenance treatments that need to be given continuously can’t cure MS, because when you stop the treatment MS disease activity tends to return and in some cases, particularly with anti-trafficking agents (natalizumab and fingolimod), to a greater extent than before, which we call MS rebound.

For arguments sake let’s say we have treated a group of pwMS early in the course of their disease with an IRT and they have gone into long-term remission with no evident disease activity (NEDA). How long should we wait before declaring a victory over their MS; 10, 15, 20 or 25 years? In the past, we have proposed defining a cure as NEDA at 15 years post-treatment as a starting point (see our MSARD Editorial below). Why 15 years? This is the most commonly accepted time-point used for defining benign MS and therefore it is a standard end-point that could potentially be accepted by the wider MS community. However, this may be wishful thinking many in the field are saying that we can’t cure MS, therefore, we should not even be having this discussion. Do you agree? 

The average time to the onset of secondary progressive MS is ~14-15 years so one would expect to see a significant proportion of people manifesting with SPMS in this 15-year timeframe. If we have gotten the autoimmune hypothesis wrong and IRTs don’t work then I would estimate at least a third of treated subjects should have SPMS at 15 years. The problem with 15 years is that it is a long wait if you have MS. Many pwMS want to know ‘now’ if an IRT offers a cure, therefore we need data to convince the naysayers to support the ‘cure hypothesis’. Hopefully, convincing data, such as the HSCT data below, will change their minds and get them to at least offer IRTs to more of their patients.

In the past, I have proposed a deep phenotyping project to look at pwMS who are NEDA-2 post-IRT to see if we can find any evidence of ongoing inflammatory, or neurodegenerative, MS disease activity. I proposed interrogating them in detail and comparing them to a similar cohort of pwMS who are being treated with maintenance DMTs. Deep phenotyping is simply a term that refers to the interrogation of the CNS to see if the IRT has stopped ongoing damage and protected reserve capacity.

The study that has come closest to reaching this 15-year time point is the Canadian myeloablative HSCT cohort (see below). Mark Freedman, the principal investigator, has told me that all of these patients remain NEDA-2 (no relapses or MRI activity) although some have worsened in relation to their disability, which may be a result of previous damage and not ongoing MS disease activity. However, the most impressive observation is that this cohort of patients, who all had very active MS prior to HSCT, has ‘normalised’ their rate of brain volume loss or atrophy after an initial precipitous drop in brain volume due to pseudoatrophy and/or chemotherapy-induced neurotoxicity. Mark Freedman has also said that about a third of these patients, who have had lumbar punctures, have lost their OCBs (personal communication). However, the spinal fluid analyses have all been done quite early after HSCT hence we don’t know how many subjects who have reached 10 years of follow-up or more have persistent OCBs. Wouldn’t this be an interesting fact to know?

When the 10-year lumbar puncture and spinal fluid analysis was done in a group of Polish subjects treated with intravenous cladribine, 50% had lost their spinal fluid oligoclonal IgG bands (OCBs) at 10 years and this group of OCB-negative patients tended to have stable disease compared to those who hadn’t lost their OCBs. This is why we are doing the SIZOMUS (Ixazomib) and the DODO (high-dose ocrelizumab) studies to try and scrub the CNS clean of pathogenic B-cells and plasma cells that may be driving low-grade smouldering MS. Exciting? You bet! These two studies are one of the reasons I get up in the morning, look at myself in the mirror and say nobody can say Barts-MS isn’t doing innovative MS research. 

The question I am now asking myself is switching a definition of a cure to a biological one a better strategy? This is a new line of thinking that has been brewing in my head for the last 12 months or so. If EBV is the cause of MS can we simply put pwMS into remission and clear them of EBV? This is why I want to do the iTeri and similar studies, i.e. to give an IRT and follow it with a drug that prevents EBV reactivation (antiviral) or scrubs B-cells of EBV (EBNA-1 antagonists). 

I am sure many cynics will be saying no not Prof G thinking aloud. Yes, I am thinking aloud. If only a minority of pwMS treated with IRTs go into long-term remission why can we increase the proportion by using the induction-maintenance approach that targets the cause of MS? What do you think?

If you agree with this strategy I am going to need help to get the iTeri concept study funded.  

DEFINING A CURE:

Banwell et al. Editors’ welcome and a working definition for a multiple sclerosis cure. Multiple Sclerosis and Related Disorders. 2013; 2(2):65-67.

…. Defining a cure in MS is a difficult task. How long should we wait before declaring a victory; 15, 20 or 25 years? Oncologists have back-tracked on this issue and instead of a cure they now prefer to use the term NEDD, or no evidence of detectable disease, at a specific time-point knowing full well that a limited number of subjects will relapse and present with recurrent disease after this point. We propose using the term NEDA, or no evident disease-activity, at 15 years as a starting point for defining a cure. Why 15 years? This is the most commonly accepted time-point used for defining benign MS and therefore it is a usual endpoint. In addition, the median time to the onset of secondary progressive MS is ~10-11 years (Kremenchutzky, Rice et al. 2006) and is well within the 15-year time window of our proposed definition of a cure. At present NEDA is defined using a composite of a) no relapses, or b) no EDSS progression, or c) no MRI activity (new or enlarging T2 lesions or no Gd-enhancing lesions) (Havrdova, Galetta et al. 2009; Giovannoni, Cook et al. 2011). This description is currently based on data that is routinely collected in contemporary clinical trials (Havrdova, Galetta et al. 2009; Giovannoni, Cook et al. 2011). The definition of NEDA will evolve with technological innovations and clinical practice, and in the future, it will almost certainly include MSer-related outcomes, grey matter disease activity, an index of brain atrophy and hopefully a CSF biomarker profile…..

References:

Giovannoni, G., S. Cook, et al. (2011). “Sustained disease-activity-free status in patients with relapsing-remitting multiple sclerosis treated with cladribine tablets in the CLARITY study: a post-hoc and subgroup analysis.” Lancet Neurol 10(4): 329-337.

Havrdova, E., S. Galetta, et al. (2009). “Effect of natalizumab on clinical and radiological disease activity in multiple sclerosis: a retrospective analysis of the Natalizumab Safety and Efficacy in Relapsing-Remitting Multiple Sclerosis (AFFIRM) study.” Lancet Neurol 8(3): 254-260

Kremenchutzky, M., G. P. Rice, et al. (2006). “The natural history of multiple sclerosis: a geographically based study 9: observations on the progressive phase of the disease.” Brain 129(Pt 3): 584-594.

THE CURE #1?

Atkins et al. Immunoablation and autologous haemopoietic stem-cell transplantation for aggressive multiple sclerosis: a multicentre single-group phase 2 trial. Lancet. 2016 Aug 6;388(10044):576-85. 

BACKGROUND: Strong immunosuppression, including chemotherapy and immune-depleting antibodies followed by autologous haemopoietic stem-cell transplantation (aHSCT), has been used to treat patients with multiple sclerosis, improving control of relapsing disease. We addressed whether near-complete immunoablation followed by immune cell depleted aHSCT would result in long-term control of multiple sclerosis.

METHODS: We did this phase 2 single-arm trial at three hospitals in Canada. We enrolled patients with multiple sclerosis, aged 18-50 years with poor prognosis, ongoing disease activity, and an Expanded Disability Status Scale of 3.0-6.0. Autologous CD34 selected haemopoietic stem-cell grafts were collected after mobilisation with cyclophosphamide and filgrastim. Immunoablation with busulfan, cyclophosphamide, and rabbit anti-thymocyte globulin was followed by aHSCT. The primary outcome was multiple sclerosis activity-free survival (events were clinical relapse, appearance of a new or Gd-enhancing lesion on MRI, and sustained progression of Expanded Disability Status Scale score). This study was registered at ClinicalTrials.gov, NCT01099930.

FINDINGS: Between diagnosis and aHSCT, 24 patients had 167 clinical relapses over 140 patient-years with 188 Gd-enhancing lesions on 48 pre-aHSCT MRI scans. Median follow-up was 6.7 years (range 3.9-12.7). The primary outcome, multiple sclerosis activity-free survival at 3 years after transplantation was 69.6% (95% CI 46.6-84.2). With up to 13 years of follow-up after aHSCT, no relapses occurred and no GdGd-enhancing lesions or new T2 lesions were seen on 314 MRI sequential scans. The rate of brain atrophy decreased to that expected for healthy controls. One of 24 patients died of transplantation-related complications. 35% of patients had a sustained improvement in their Expanded Disability Status Scale score.

INTERPRETATION: We describe the first treatment to fully halt all detectable CNS inflammatory activity in patients with multiple sclerosis for a prolonged period in the absence of any ongoing disease-modifying drugs. Furthermore, many of the patients had substantial recovery of neurological function despite their disease’s aggressive nature.

THE CURE #2?

Rejdak et al. Cladribine induces long lasting oligoclonal bands disappearance in relapsing multiple sclerosis patients: 10-year observational study. Mult Scler Relat Disord. 2019 Jan;27:117-120. 

Background: There has been long-term interest in cladribine as a drug for the treatment of MS. The current study focused on the effect of cladribine on oligoclonal bands (OCB) expression in the CSF in relapsing-remitting MS (RRMS) patients observed over 10 years.

Methods: 29 treatment-naive subjects with RRMS were prospectively enrolled and received induction therapy with subcutaneous parenteral cladribine (at a cumulative dose of 1.8 mg/kg; divided into 6 courses every 5 weeks given for 4-6 days, depending on patients’ body weight). Selected patients received maintenance doses in the follow-up period.

Results: Isoelectric focusing revealed that 55% of patients did not have OCB in CSF after cladribine treatment as compared to baseline testing when 100% of patients were positive for OCB. There were no significant differences in Expanded Disability Status Scale scores at baseline and at the end of treatment cycle between OCB-positive vs. OCB-negative subgroups. At the last follow-up, OCB-negative patients had lower disability compared to OCB-positive patients (p = 0.03).

Conclusion: Cladribine-induced immune reconstitution leads to long lasting suppression of intrathecal humoral response, which might be an additional mechanism that enhances the therapeutic effect on disease progression in RRMS patients.

Conflicts of Interest

Preventive Neurology

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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. 

Do you want a cure?

MSers want a cure. However, even if we have an MS cure in hand we may not prevent or reverse progressive disease. How can this be?

Focal inflammation damages nerves in two ways. It can shred and destroy nerve fibres as part of the initial inflammatory stage (acute neurodegeneration) or it can damage nerves and leave them functioning, but the resulting damage primes them to die off in the future; I call this delayed neurodegeneration.

The mechanisms that result in delayed neurodegeneration of nerves or smouldering MS are many and include innate immunity (hot microglia), energy deficits (mitochondrial dysfunction), excitotoxicity (calcium overload), free radicals (oxygen and nitrogen radicals), premature ageing, intrathecal plasma cell production of pathogenic autoantibodies, etc.

Clearly, anti-inflammatory drugs that prevent new lesions formation, such as natalizumab, alemtuzumab and ocrelizumab, will not be able to prevent the delayed neurodegeneration from previous inflammatory lesions. What has happened in the past has happened; i.e. the water under the bridge analogy. So if you have relapsing MS and have had a lot of inflammatory activity in the past that have damaged many nerve fibres, even if you go onto a highly effective DMT that renders you NEDA, it is not going to prevent the ongoing loss of nerve fibres that are primed to die off from previous inflammation in the future. This is why did the PROXIMUS trial and are promoting the OXO trial; add-on neuroprotective drug to try and modify the delayed die-off of neurons and axons.

What protects you from entering the clinically-apparent secondary progressive phase of the disease is reserve capacity, i.e. the surviving healthy nerve fibres in nerve pathways keep you functioning normally. I suspect that MSers, who have been treated with highly-effective DMTs and have now become secondary progressive, had a low reserve capacity and a large number of damaged nerve fibres that had been primed to die off in the future. In other words, they were treated with DMTs too late to prevent SPMS. This is why we keep pushing the message ‘early effective treatment’ is the only way to prevent secondary progressive MS.

There are two conclusions to be drawn from these observations; (1) it is best to have your MS treated effectively early in the disease course to maximise your reserve capacity, and (2) we need additional add-on neuroprotective therapies to target the delayed neurodegenerative processes referred to above. The latter includes avoiding or reversing factors that prematurely age the nervous system.

The ageing hypothesis of progressive MS is a major factor that underpins our Brain Health campaign, which targets non-specific factors that have been associated with more rapid progression in MS (smoking, co-morbidities, lack of exercise, infections, etc.).  

So unless you are rendered NEDA early in the course of your disease it may not prevent you from entering the progressive phase of the disease, i.e. it will not be the panacea you want. In addition, our licensed DMTs don’t kill long-lived plasma cells that continue to make intrathecal (within the CNS) antibodies that my drive progressive MS. The exception may be natalizumab. There are several reports of MSers on natalizumab losing their OCBs (oligoclonal bands or antibody bands). It now emerges that plasma cells live in a ‘niche’ or home and that to keep them in the niche they use the VCAM-1-VLA-4 adhesion molecule interaction. Natalizumab disrupts this interaction and hence it is plausible that natalizumab may reduce the life expectancy of intrathecal (inside the CNS) plasma cells. If this proves to be the case natalizumab may still have the edge on the other DMTs in this regard.

To target plasma cells, which are long-lived, we will need add-on therapies. This is high on our list of priorities and we are starting the SIZOMUS trial to test a therapy for myeloma (malignant plasma cells) in MS. Can we scrub the MS brain free of plasma cells?

CoI: multiple

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