Prof G do you think disability improvement is a reasonable treatment goal?
NEDADI = no evident disease activity and disability improvement
Two weeks ago one of my patients with PPMS, who we treated with off-label subcutaneous cladribine, came for her annual follow-up appointment. Despite being treated with cladribine over 2 years ago she has unfortunately progressed from EDSS 5.5 to 6.5. Her latest MRI brain did not show any new T2 lesions. She asked why we hadn’t scanned her spinal cord. She is desperate for us to find some disease activity so that she can be retreated or preferably offered ocrelizumab. She has a well-off family member who is prepared to cover the costs of ocrelizumab treatment privately. What should I do?
As you know I don’t support private prescribing in the NHS as it undermines the NHS’ founding principles; free at the point of access and equity. However, it is difficult to say no to private prescribing if a patient insists, particularly as there is now a mechanism to do this under the NHS. I am also first a doctor looking after the individual patient and this takes priority over my duty as an NHS employee and guardian of its socialist healthcare ideals.
I didn’t agree to a private prescription for ocrelizumab. Instead, I batted the problem into the long grass and agreed to bring her via our planned investigation unit for an MRI of the spine and lumbar puncture to measure CSF neurofilament levels. If there are new spinal cord lesions and/or a raised CSF neurofilament level then we could potentially look at an additional course of cladribine, off-label rituximab under the NHS, private ocrelizumab or possible recruitment into a clinical trial. I suspect that the MRI will show no new lesions and the CSF NFL levels will be normal. If this is the case then she has NEDA with worsening disability. I did refer her to my blog post on this issue (EXPLAINING WHY YOU GET WORSE DESPITE BEING NEDA) so she could get some understanding of what was happening to her.
During the consultation, she asked me ‘why a friend’s daughter with very bad MS, who had been treated with alemtuzumab, had made such a remarkable recovery?’ Apparently, this young woman had been rendered partially paraplegic from a spinal relapse and after alemtuzumab had recovered function and was now walking almost ‘normally’ again. My patient wanted to know why there was such a difference between herself, someone with PPMS, and her friend’s daughter a young woman with highly-active RRMS.
You may remember the other day I asked you to guess why I was so impressed with the HSCT-MIST trial. Let me try and explain why.
Should we be changing our expectations of what DMTs can offer pwMS? Are we entering an era when the expectation of disability improvement becomes the norm? I certainly hope so.
The most impressive aspect of the recent HSCT-MIST trial was not the NEDA data or the improved safety of HSCT, which are obviously important, but the disability improvement data. During the first year post-HSCT the mean EDSS scores improved from 3.4 to 2.4 vs. a worsening from 3.3 to 4.0 in those on the basket of licensed DMTs. Is this unique to HSCT? How does this HSCT data compare to other treatment options?
The first DMT to show a convincing impact on disability improvement in a phase 3 controlled trial was with natalizumab in the AFFIRM study; at 2 years the probability of a sustained improvement in disability was 30% for natalizumab-treated patients and 19% for patients who received placebo.
Phillips et al. Sustained improvement in Expanded Disability Status Scale as a new efficacy measure of neurological change in multiple sclerosis: treatment effects with natalizumab in patients with relapsing multiple sclerosis. Mult Scler. 2011 Aug;17(8):970-9.
The next convincing phase 3 result was with alemtuzumab-treated patients in the CARE-MS2 trial; alemtuzumab-treated patients were more than twice as likely as IFN-β-1a-treated patients to experience 3-month confirmed disability improvement (35% vs 19%).
Giovannoni et al. Alemtuzumab improves preexisting disability in active relapsing-remitting MS patients. Neurology. 2016 Nov 8;87(19):1985-1992.
Unfortunately, the latest HSCT trial did not report their disability improvement data as confirmed or sustained disability improvement at 3 months. The main reason for this was methodological in that patients patients on DMTs had a rescue option of being treated with HSCT. However, in the first 12 months, 12/55 (22%) of patients on DMTs compared to 38/55 (69%) who were treated with HSCT had an improvement in their EDSS. Based on the final data set I suspect that in a large proportion of the HSCT patients the improvements were sustained.
Burt et al. Effect of Nonmyeloablative Hematopoietic Stem Cell Transplantation vs Continued Disease-Modifying Therapy on Disease Progression in Patients With Relapsing-Remitting Multiple Sclerosis: A Randomized Clinical Trial. JAMA. 2019 Jan 15;321(2):165-174.
What about the new kids on the block, i.e. ocrelizumab and cladribine? Unfortunately, we don’t have published data on cladribine, but I will try and rectify this and will ask for the analysis to be done. However, the phase 3 pooled OPERA data of ocrelizumab has been published; 21% of ocrelizumab-treated patients had disability improvement confirmed after at least 12 weeks compared to only 16% of IFN-β-1a-treated patients.
Hauser et al. Ocrelizumab versus Interferon Beta-1a in Relapsing Multiple Sclerosis. N Engl J Med. 2017 Jan 19;376(3):221-234.
So the league table for disability improvement of HSCT over alemtuzumab, over natalizumab, followed by ocrelizumab seems to mirror the brain atrophy or end-organ damage data. Are you surprised? I am not. A large driver of disability improvement is reserve capacity, i.e. brain reserve or put simply the size of your brain, which predicts and provides the substrate for recovery. This is another reason why you would want your MS treated early and just maybe you would want to flip the pyramid and go for the DMTs that offer you the best chance of disability improvement.
Hidden in this data may be a clue about the pathogenesis of MS. What differentiates HSCT and alemtuzumab from natalizumab and then from ocrelizumab? Could it be the transient depletion and reconstitution of the T-cell compartment?
Joanne Jones and her colleagues from Cambridge showed that among trial participants with no clinical disease activity immediately before treatment, or any clinical or radiological disease activity on-trial, disability improved after alemtuzumab but not following interferon β-1a. They suggested that this disability improvement after alemtuzumab could not be attributable to its anti-inflammatory effects and suggested that T lymphocytes, reconstituting after alemtuzumab, permit or promote brain repair via the production of growth factors in particular brain-derived neurotrophic factor (BDNF), platelet-derived growth factor (PDGF) and ciliary neurotrophic factor (CNTF). If their hypothesis holds out then this may be another reason why NIRTs (non-selective immune reconstitution therapies) outperform SIRTs (selective immune reconstitution therapies) in going beyond NEDA, i.e NEDADI. And just maybe you need these cells to traffic to the central nervous system to deliver these growth factors.
Jones et al. Improvement in disability after alemtuzumab treatment of multiple sclerosis is associated with neuroprotective autoimmunity. Brain. 2010 Aug;133(Pt 8):2232-47.
Another piece of the puzzle is the positive effect alemtuzumab has on the MRI metric called magnetization transfer ratio or MTR, which is a measure of tissue integrity. In a small study, the mean MTR fell in 18 untreated MSers in normal-appearing grey and white matter. Conversely, mean MTR was stable in 20 alemtuzumab-treated MSers, which suggests alemtuzumab protects against tissue damage. This MTR data mirrors the clinical observations and is congruent with some of the basic science. Wouldn’t it be nice to do an experiment of using natalizumab post-alemtuzumab to see if by blocking T-cell trafficking we blunt the alemtuzumab-associated improvement in disability, i.e. to test whether T-cell trafficking is required to drive repair mechanisms?
Button et al. Magnetization transfer imaging in multiple sclerosis treated with alemtuzumab. Mult Scler. 2013 Feb;19(2):241-4.
So what do I tell my patient? Do I tell her that the reason why she has not improved is that she is older, has more advanced MS and hence less reserve capacity to allow disability improvement? Or that we may not have tackled the root cause of her MS with subcutaneous cladribine? I stuck to the former explanation as the latter is simply a hypothesis that needs more thinking, more debate and some new experiments to establish if the treatment hierarchy in relation to end-organ damage and disability improvement is based on the different modes of action of our DMTs.
Despite the reasons behind these observations we are now entering an era were disability improvement is not an unreasonable expectation for pwMS, provided they are treated early and with high-efficacy DMTs.
How many you have been told about disability improvement on DMTs?
CoI: multiple, please note that I am a co-author on the natalizumab, alemtuzumab and ocrelizumab disability improvement papers.