“Dawson’s fingers” is the name for the lesions around the ventricle-based brain veins of patients with multiple sclerosis. The condition is thought to be the result of inflammation or mechanical damage by blood pressure around long axis of medular veins.
Dawson’s fingers spread along, and from, large periventricular collecting veins, and are attributed to perivenular inflammation.
Lesions far away from these veins are known as Steiner’s splashes.
Sometimes experimental autoimmune encephalomyelitis has been triggered in humans by accident or medical mistake. The damage in these cases fulfils all the pathological diagnostic criteria of MS and can therefore be classified as MS in its own right. The lesions were classified as pattern II in the Lucchinetti system. This case of human EAE also showed Dawson fingers.
Results presented at the 32nd Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) provided additional details from a 60-month, phase III clinical trial of the experimental oral therapy siponimod (BAF312, Novartis Pharmaceuticals AG) involving 1,651 people with secondary progressive MS.
The trial met its primary endpoint of reducing the risk of disability progression compared with inactive placebo. Those on active treatment had a 21% reduced risk of disability progression compared to those on placebo. Secondary endpoints suggested that those on active therapy had 23.4% lower average change in brain volume and reduced lesion volume.
The therapy was generally well tolerated and similar to adverse events reported for similar compounds.
Background: Siponimod (BAF312) is an experimental immune system-modulating therapy that was designed to be a more selective sphingosine 1-phosphate receptor modulator than Gilenya® (fingolimod, Novartis International AG). Gilenya, was approved in 2010 for adults with relapsing forms of MS to reduce the frequency of clinical relapses and to delay the accumulation of physical disability. Siponimod previously demonstrated safety and efficacy on MRI scans in a phase II study in people with relapsing-remitting MS (The Lancet Neurology, 2013 Aug;12(8):756-67). Siponimod is thought to act by retaining certain white blood cells in the body’s lymph nodes, keeping them out of circulation and from entering the central nervous system. Siponimod also distributes effectively to the central nervous system (brain and spinal cord) where it may have direct anti-inflammatory or other effects.
The Study: Participants were randomly assigned to take siponimod or placebo capsules daily for up to 60 months. The primary endpoint of the study was reducing the risk of disability progression, as measured by the EDSS scale at three months. Secondary endpoints included reducing the risk of disability progression as measured by the EDSS at six months versus placebo, the risk of worsening mobility as measured by the timed 25-foot walk test, disease activity as observed on MRI scans, relapse rate, and safety/ tolerability.
Results: Results were presented at the 32nd Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) on September 17, 2016. The trial met its primary endpoint of reducing the risk of disability progression compared with inactive placebo. Those on active treatment had a 21% reduced risk of disability progression (confirmed at 3 months) compared to those on placebo. Secondary endpoints suggested that those on active therapy had at 26% reduced risk of disability progression (confirmed at 6 months), a 23.4% lower average change in brain volume, and reduced MRI-detected brain lesion volume. There was no significant difference seen between groups in the timed 25-foot walk. Relapse rates were significantly lower in those taking siponimod.
Safety: The therapy was generally well tolerated and similar to adverse events reported for similar compounds. Serious adverse events occurred in 16.7% of participants. The serious adverse events reported to be more likely for those taking siponimod included nervous system disorders and infections.
Comment: “These results suggest a modest benefit for people with secondary progressive MS, which is a positive step forward in the global effort to speed solutions for people living with this chronic form of the disease,” said Timothy Coetzee, PhD, Chief Advocacy, Services and Research Officer at the National MS Society. “We look forward to learning additional details about its potential benefit and safety.”
Researchers have developed an antibody with potential therapeutic effects against multiple sclerosis. The discovery opens up a new strategy for controlling the disease.
For the cells of the immune system circulating in the bloodstream to reach the central nervous system, they must penetrate the blood-brain barrier and blood-spinal cord barrier. During previous work, the authors studied a factor involved in opening the blood-brain barrier, the NMDA receptor. They found that blocking the interaction of this receptor with tPA has beneficial effects linked with maintaining the integrity of the barrier.
Scientists at the Institut National de la Santé et de la Recherche Médicale, in France, developed a monoclonal antibody (Glunomab) directed against the specific site on the NMDA receptor to which tPA binds. In cellular models of the human blood-brain and blood-spinal cord barriers, the use of this antibody prevented opening of the barrier under inflammatory conditions, limiting the entry of lymphocytes. The team then tested the therapeutic effects of the antibody in an experimental mouse model of MS. After intravenous injection of Glunomab, the progression of partial or total paralysis of the limbs – as assessed by a clinical score – was blocked. In these treated mice, this effect was linked with reduced infiltration of lymphocytes into the nervous tissue, and reduced demyelination.
Results of mouse model studies sometimes do not translate to humans and may be years away from being a marketable treatment. However, the authors argue that by preventing myelin destruction by the cells of the immune system, this strategy might represent a promising therapy for the control of MS.
The study was published in the journal Brain.
“These results suggest that aggressive MS may be stopped with an effective but risky procedure, for a subset of people,” said Dr. Bruce Bebo, Executive Vice President, Research, at the National MS Society. “Additional research by investigators around the world is focusing on figuring out who might benefit from this procedure and how to reduce its risks, which can include death.”
Background: An experimental procedure that has been explored for several years in MS is called “autologous hematopoietic (blood cell-producing) stem cell transplantation” – or HSCT. This procedure has been used in attempts to “reboot” the immune system, which launches attacks on the brain and spinal cord in people with MS.
In HSCT, the stem cells (derived from a person’s own bone marrow or blood) are stored, and the rest of the individual’s immune cells are depleted by chemotherapy. Then the stored stem cells are reintroduced by infusion into the vein. The new stem cells migrate to the bone marrow and over time produce new blood cells, including immune cells. The goal of this currently experimental procedure is to establish a new immune system that no longer recognizes myelin and other nervous system tissue as dangerous. In theory, this should stop the attacks that lead to tissue damage and disability.
There are a number of laboratories around the world testing variations of HSCT for the treatment of autoimmune diseases, including MS. Preliminary findings suggest this is a promising, but potentially risky strategy for the treatment of MS.
The Study: Drs. Harold Atkins, Mark Freedman and team at the Ottawa Hospital, University of Ottawa and other institutions in Canada conducted a Phase 2 trial of HSCT that involved 24 people with aggressive relapsing-remitting MS whose disease was not controlled with available therapies. No control group was used which would have enabled comparison against the results found in the treatment group. The procedure used by this group included complete destruction of bone marrow cells and an additional step that enriched the transplanted cells for stem cells.
Results – Safety: One of the participants died of transplantation-related complications that caused liver failure and another required intensive hospital care for liver complications. The treatment regimen was modified over the course of the study to reduce toxicity, but all participants still developed fevers, which were frequently associated with infections.
Results – Effectiveness: Three years after the procedure, 70% of the participants remained free of disease activity, meaning they had no relapses, no new MRI-detected inflammatory brain lesions, and no signs of progression. The remaining 30% experienced progression of disability. In addition, for the entire follow-up period ranging from 4 to 13 years after the procedure, of the 23 survivors:
The results were published online on June 9, 2016 in The Lancet. Major funding for the study came from the MS Society of Canada and its affiliated Multiple Sclerosis Scientific Research Foundation.
Next Steps: Rigorous clinical trials of stem cell therapies are needed to determine their safety and effectiveness in people with MS. Trials of this and other stem cell therapy approaches are taking place in Canada, the United States, Europe and elsewhere. To help explore the potential of stem cell therapy, in November 2015, the International Conference on Cell-Based Therapy for Multiple Sclerosis was convened in Lisbon, Portugal under the auspices of the International Advisory Committee on Clinical Trials in MS (a group jointly sponsored by the National MS Society and the European Committee for Treatment and Research in Multiple Sclerosis). Seventy leading researchers and clinicians conferred on clinical trials needed to provide answers about which types of cells, which route of delivery, and which types and stages of disease, would be the most promising approach for treating MS. Read more about this meeting
Researchers at the University of British Columbia have uncovered a rare gene mutation that appears to dramatically increase the risk, in some individuals, of developing a severe form of progressive multiple sclerosis. While the cause of MS is not known, scientists believe several different factors, including susceptibility genes, may interact to trigger the disease. The gene was discovered in two unrelated families that had multiple members with MS. The researchers also determined that the gene (NR1H3) contains instructions for a protein called LXRA, which is thought to be a control switch for genes involved in many functions, including some that help control inflammation and integrity of nerve-insulating myelin in the brain and spinal cord. This type of discovery can provide crucial clues to biological pathways that underlie MS, and may lead to new approaches for stopping MS and restoring function. The study, by Drs. Carles Vilariño-Güell, Weihong Song, A. Dessa Sadovnick and others, was funded in part by the MS Society of Canada and appeared in the journal Neuron on June 1, 2016.
Background: Mitoxantrone is a powerful immune-suppressing therapy. Prior to its approval for use in MS, it was used only to treat certain forms of cancer. It acts in MS by suppressing the activity of immune T cells, B cells, and macrophages that are thought to lead the attack on nerve-insulating myelin. The U.S. Food and Drug Administration approved mitoxantrone for reducing neurologic disability and/or the frequency of relapses in people with secondary progressive MS or worsening relapsing-remitting MS. The total lifetime dose is limited to avoid possible heart damage. Acute myeloid leukemia has been previously reported in people treated with mitoxantrone for MS or cancer.
The Study: Investigators identified 677 people with MS seen at the University of Würzburg MS center between January 1994 and December 2007 who had received mitoxantrone. They were able to follow up with 676 of these patients.
The results show that 37 people developed cancer after taking mitoxantrone, including nine cases of breast cancer, seven cases of colorectal cancer, and four cases of acute myeloid leukemia. The rate of acute myeloid leukemia was 10 times that seen in the general population in Germany. The rate of colorectal cancer was three times that seen in the general population in Germany. The rate of breast and other cancers was not increased over that seen in the general population in Germany. Older age at treatment was associated with increased risk of cancer, but not prior use of other immunosuppressive treatments, or duration of treatment with mitoxantrone.
The team (led by Dr. Mathias Buttmann, University of Würzburg, Germany) has published results in Neurology (published early online, May 11, 2016).
Comment: The authors state that if the findings are confirmed, “posttreatment colonoscopy might improve the risk-benefit ratio of this highly active immunosuppressive drug,” since if found early enough, colorectal cancer is curable. They also note that mitoxantrone is currently the only MS therapy approved for treating secondary progressive MS, and that the overall rate of cancers may still justify the use of mitoxantrone in people who are severely affected with MS and where there are no better treatment options available.
Background: In MS, the immune system attacks and destroys myelin, the fatty substance that surrounds and protects the nerve fibers, and the nerve fibers can also be damaged. Current therapies are largely aimed at dampening the immune attacks. However, a therapy that repairs damage to myelin and nerve fibers is also necessary.
A team at the University of California, San Francisco led by National MS Society-funded Harry Weaver Neuroscience Scholar Jonah Chan, PhD, invented a new micropillar technology to rapidly identify compounds that stimulate the regrowth of myelin. The team initiated a screen using this technology, testing a library of 1000 drugs already approved by the FDA for other conditions for their ability to promote the development of myelin-making cells and wrapping of myelin around the micropillars. Clemastine, an oral antihistamine used to treat allergy symptoms, was identified through this process. Dr. Chan was the first recipient of the Barancik Prize for Innovation in MS Research for this pioneering work.
The Clinical Trial: Ari Green, MD, led the team conducting the clinical trial. They administered oral clemastine or inactive placebo twice daily to 50 people with MS and optic nerve damage for 150 days. For the first three months of the study, people were given either clemastine or a placebo, and for the second two months, those initially given clemastine received the placebo and vice-versa. Tests were performed before and after treatment that measured visual evoked potentials. Visual evoked potentials measure transmission of electric signals along optic nerve pathways in response to stimulation. Delays in this transmission occur when the myelin is damaged and if these delays are reduced, it is an indication that myelin repair is occurring along the nerve pathways. (Participants had significant delays in transmission in at least one eye.)
Delays in visual evoked potential were reduced by 1.9 milliseconds per eye, a statistically significant result. The results hinted at a reduction in vision impairment as well, but it did not reach statistical significance. Fatigue increased mildly in participants taking clemastine.
Clemastine is an over-the-counter allergy medication. Doses in this trial exceeded the maximum recommended for over-the-counter use. Also, clemastine affects a range of targets in the body, and involves the risk for side effects, particularly at increased dosages.
Dr. Green cautions that more research with larger numbers of people is needed before doctors can recommend clemastine as a treatment for people with MS. This team is planning an additional trial to further determine the safety and effectiveness of clemastine, as well as studies to identify compounds that may enhance myelin repair and cause fewer side effects.
Drs. Green and Chan both received Society funding to launch their early careers as independent researchers focused on MS, including Harry Weaver Neuroscience Scholar Awards.
Comment: “This preliminary report is exciting, and we look forward to seeing the full results of this clinical trial of clemastine presented and then published,” says Bruce Bebo, PhD, Executive Vice President, Research at the National MS Society. “Finding a way to repair nervous system damage to restore function to people with MS is a very high research priority.”
The 2016 Annual Meeting of the American Academy of Neurology will take place in Vancouver, BC, Canada, April 15-21. The National MS Society will be providing reports summarizing studies. Anyone can get a preview of the technical summaries, or abstracts, of presentations to be given at the meeting at this link, free of charge.
• The results from two recently published laboratory studies suggest that high levels of salt shift the balance of the immune system toward inflammation, and that salt alters the function of several types of immune cells pertinent to MS.
• These two studies, which were both published in the Journal of Clinical Investigation, were led by Dr. David Hafler (Yale University) and Dr. Dominik Müller (Max-Delbruck Center, Berlin, Germany).
• Dr. Hafler is funded by the National MS Society to study the impact of high salt on the immune system, and the Yale team is also conducting a pilot clinical trial to explore the impact of high- and low-salt diets on MS disease activity.
Background: Eating high levels of salt, which is part of the typical Western diet, has been linked to heart disease, chronic inflammation, and cancer. Recent lab reports have also suggested that dietary salt can speed the development of the immune attack in an MS-like disease in mice, and that the mouse disease responds differently to salt depending on the gender and genetic makeup of the mice. One small study in people found a possible link between dietary salt levels and relapses in people with MS, but this study suggested a link, which is not the same as establishing an actual cause. So far, laboratory findings related to the effects of salt have been stronger than the few studies that have been reported in people. Understanding whether high dietary salt is a risk factor for developing MS or for worsening disease activity is an active area of research.
The Studies: Two studies recently published in the Journal of Clinical Investigation suggest that high dietary salt affects two types of immune cells in a way that increases inflammation, a state that is generally considered harmful in MS. A study by National MS Society-supported researchers at Yale University and Harvard Medical School led by David Hafler, MD, investigated the effects of high salt on regulatory immune cells called “Tregs.” Tregs normally suppress immune responses by other immune cells, but in people with MS Tregs have been shown to be less able to perform this helpful function to turn off attacks. The team showed in mice and in cells in lab dishes that high salt blocks the ability of Tregs to suppress potentially harmful immune cells, and shifts Tregs toward activity that increases inflammation.
The other study, by an international team led by Dominik N. Müller at the Max-Delbruck Center in Berlin, Germany, investigated immune cells called “macrophages.” This study showed that high salt blocks the activation of a subset of macrophages, reducing their ability to suppress inflammatory cells and creating an imbalance in the immune system. In mouse models, high salt diets also delayed wound healing.
Comment: Taken together, these laboratory studies add new evidence that high levels of dietary salt may increase inflammation and autoimmunity, and decrease the ability of regulatory cells and processes to limit harmful immune cell activity. More studies are needed to determine the possible role of a high-salt diet in the risk of developing MS and whether reducing salt intake may be helpful for reducing disease activity in people with MS. Dr. Hafler is funded by the National MS Society to study the impact of high salt on the immune system, and the Yale team is also conducting a pilot clinical trial to explore the impact of high- and low-salt diets on MS disease activity.