Tag: free light chains

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.

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