What’s New in MS Research – September 2023

Reviewed by MSAA Chief Medical Officer Barry A. Hendin, MD

This edition of “What’s New in MS Research” opens with a pair of “firsts:” the first listing of multiple sclerosis (MS) therapies on the World Health Organization’s List of Essential Medicines and the first United States Food and Drug Administration (FDA) approval of a biosimilar therapy for the long-term treatment of MS.

Those developments reflect an increasing awareness among public health officials internationally and in the United States that it is critical for people with MS to have access to the therapies that can make a real difference in their lives.

The other items in this iteration of “What’s New in MS Research” highlight the many avenues of inquiry researchers are pursuing to develop, assess, and optimally employ disease-modifying therapies (DMTs), other MS-focused treatments, and additional interventions to promote the overall health and well-being of people living with multiple sclerosis.

For first time, MS therapies included on WHO list of essential medicines

The World Health Organization (WHO) in July 2023 added three disease-modifying therapies (DMTs) for multiple sclerosis to its list of “Essential Medicines,” marking the first time that MS treatments have been included on the roster. 1

The DMTs added to the list are Mavenclad® (cladribine); glatiramer acetate, which is marketed as Copaxone® and in a generic formulation; and rituximab, which is marketed in the United States as Rituxan®. While Rituxan has many FDA-approved uses in cancer and other conditions, it is not approved in the United States for the treatment of MS.

The WHO said that it chose those medications for its list because all three have been shown to delay or prevent progression of MS and because they have different routes of administration, prices, and roles in treating the disease. Mavenclad is provided as tablets taken by mouth, while glatiramer acetate is given by injection, and rituximab is administered by intravenous infusion. In a press release, the organization explained that adding MS therapies to its list “is aimed at facilitating improved access to treatment for people living with MS around the world. The decision to support off-label use of ritixumab is supported by strong evidence of its efficacy and safety for this indication.”

The MS Coalition (MSC), a network of nine member organizations that include MSAA, applauds the WHO’s inclusion of MS disease-modifying treatments (DMTs) on the Essential Medicines List (EML) as part of its commitment to brain health. As the MSC notes, “This decision is an important step to increasing worldwide access to life-changing medications. Affordable access to DMTs is essential for all people with MS and aligns with the Coalition’s mission to improve the quality of life for those affected by MS. While there are far more DMTs available in some parts of the world, the inclusion of these DMTs on the EML list represents a giant step forward towards equitable access around the world.”

In addition, MSAA would like to recognize the MS International Federation (MSIF) for their vital role in advocating for this urgently needed inclusion of MS disease-modifying treatments (DMTs) on the WHO Essential Medicines List. Headquartered in London, the MSIF is a unique global network of 48 MS organizations as well as members of the MS community – including people with MS, volunteers, and staff in many countries. In collaboration with other health groups, the MSIF applied for the inclusion of MS medications in December 2022, following several years of work toward this goal by experts from around the world.

Beyond the specific therapies the WHO chose to place on the list, this first-ever inclusion of DMTs represents an important precedent for MS medications as a whole and recognition of the need to provide people with MS with ready access to therapies.

In another first, the FDA approves a biosimilar for relapsing forms of MS

In August 2023 the Food and Drug Administration (FDA) approved Tyruko® (natalizumab-sztn), making that medication the first biosimilar to be approved for the long-term treatment of MS.2

Marketed by Sandoz, Tyruko is a biosimilar to Tysabri® (natalizumab), a disease-modifying therapy for MS that was approved in 2004 and is given via IV infusion every four weeks. The advantages of having generic, biologic, and biosimilar products available often include greater accessibility to the medication, potential savings, and continued product development through competition.

According to the FDA, “Biological products include medications for treating many serious illnesses and chronic health conditions, including MS. A biosimilar is a biological product that is highly similar to, and has no clinically meaningful differences from, a biological product already approved by the FDA (also called the reference product). This means patients can expect the same safety and effectiveness from the biosimilar as they would the reference product.”

As with Tysabri, Tyruko is approved to treat relapsing forms of MS, which include clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), and active secondary-progressive MS (SPMS). Because it is a biosimilar, Tyruko is given at the same dosage and via the same administration as Tysabri, while also carrying the same benefits and risks.

Tysabri’s benefits – when compared to placebo over a two-year period – include a 67% decrease in the number of relapses, a 92% reduction in lesions, and a reduction in disability progression (42% reduction over three months and 54% reduction over six months). Common side effects include headache and fatigue, infections such as upper respiratory tract infection (URTI) and urinary tract infection (UTI), as well as infusion reactions.

Tysabri is a monoclonal antibody that acts against a molecule involved in the activation and function of lymphocytes, which are immune system cells produced to fight infection and disease. It also acts against the passage of lymphocytes into the central nervous system (CNS). Tysabri increases the risk of progressive multifocal leukoencephalopathy (PML), a rare but potentially fatal brain infection caused by the JC virus. Given that natalizumab products increase the risk of PML, all such medications are required to have dedicated Risk Evaluation and Mitigation Strategy (REMS) programs.

Phase I study looks at ANK-700, an experimental “inverse vaccine” for MS

With MS, the immune system becomes misdirected and attacks the myelin and the nerves of the central nervous system (CNS). Following successful results in a study of mouse models with experimental autoimmune encephalitis (EAE), an induced illness that causes MS-like symptoms and damage, ANK-700 is currently being tested in humans for safety. This experimental treatment is often referred to as an “inverse vaccine,” which means that rather than train the immune system to attack specific targets such as those that cause infection, ANK-700 is designed to train the immune system to be tolerant of specific targets: in this case, the body’s own myelin.

With regard to the mouse models, researchers found that both for those with a relapsing form of EAE or a progressive form, a research candidate with the same type of “inverse vaccine” design was able to stop the immune system’s attack on myelin. The nerves of the treated mice were able to regain function and the MS-like symptoms were reversed.

According to an article published online by Multiple Sclerosis News Today, “Scientists previously discovered immune tolerance against a target could be achieved by tagging the target with a sugar molecule called N-acetylgalactosamine or pGal. This molecule prompts the target to be taken up by regulatory immune cells that activate tolerance processes in other immune cells.”3

A press release from the University of Chicago’s Pritzker School of Molecular Engineering (PME) explains that this new type of vaccine developed by their researchers “has shown in the lab setting that it can completely reverse autoimmune diseases like multiple sclerosis and type 1 diabetes — all without shutting down the rest of the immune system.”4

Readers should note that initially, many experimental treatments for MS show positive results in animal studies, but only a small fraction of these treatments advance to human studies and ultimately show both safety and efficacy. While ANK-700 still has a long road of studies ahead to see how it may affect disease activity in individuals with MS, these types of experimental treatments are exciting to hear about and provide much hope for the future. This study was funded by ANK-700’s developer, Anokion, and details were published on September 7, 2023 in Nature Biomedical Engineering.5

Ibudilast shows favorable effect on measure linked to disability progression in progressive MS

The anti-inflammatory medication ibudilast preserved the integrity of brain tissue in people with progressive forms of MS in a Phase II clinical trial, researchers reported.6

Ibudilast is an oral medication used to treat asthma in Japan and South Korea. The biopharmaceutical company MediciNova is evaluating the therapy for potential roles in progressive forms of MS, amyotrophic lateral sclerosis (ALS), and other conditions.

Researchers analyzed data from the SPRINT-MS trial to evaluate the impact of ibudilast on tissue integrity and volume in the thalamus, a small, grey matter structure of the brain that relays motor and sensory signals to other regions of the brain.

In the trial, 255 people with progressive MS were assigned in a random fashion to receive either ibudilast or placebo. Investigators then used magnetic resonance imaging (MRI) to assess the thalamic magnetization transfer ratio (MTR), which is a measure of tissue integrity and demyelination, and thalamic volume (TV) over 96 weeks.

Relative to placebo, ibudilast had a more favorable impact on thalamic MTR. Noting that thalamic MTR is associated with confirmed disability progression, the researchers said that this finding suggested “a clinically relevant effect on thalamic tissue integrity.” However, ibudilast was not shown to have an effect on thalamic volume, which the investigators said suggested “that thalamic atrophy is more closely associated with global inflammatory activity than local tissue integrity.”

The findings follow publication of the SPRINT-MS trial’s main results in The New England Journal of Medicine in 2018.7 The study found that, relative to placebo, ibudilast cut the rate of brain atrophy – the trial’s primary endpoint – roughly in half over 96 weeks. This latest analysis builds on that welcome news and provides further hope that the years ahead will see an expansion of the treatment choices available for people with primary-progressive and secondary-progressive MS.

Encouraging news on OCREVUS® for people with primary-progressive MS

In 2017, Ocrevus® (ocrelizumab) became the first disease-modifying therapy approved by the Food and Drug Administration (FDA) for the treatment of primary-progressive multiple sclerosis (PPMS). The FDA’s approval was based on the results of the Phase III ORATORIO trial, which found that people with PPMS who received Ocrevus had lower rates of disease progression than study participants who received placebo.8

The approval represented a great advance for people with PPMS (while several investigational medications currently are being evaluated in PPMS, Ocrevus remains the only FDA-approved therapy for the condition). However, ORATORIO limited its assessment of Ocrevus in people with PPMS to those who were 18 to 55 years of age, who had an Expanded Disability Status Scale (EDSS) score of 3.0 to 6.5, and who met other requirements. Because of those criteria, patients and clinicians have not had data on the efficacy and safety of the medication in people older or younger than the study population or in those with an EDSS score lower or higher than the range included in the trial. (The EDSS runs from 0 to 10, with a higher score indicating greater disability.)

A group of Italian researchers recently helped fill in that evidence gap by conducting a retrospective study that compared outcomes in people with PPMS who did, and did not, meet the age and EDSS criteria used in ORATORIO.9 The study focused on 589 people who were treated with Ocrevus between May 2017 and June 2022. Of the total, 149 met the ORATORIO criteria and 440 did not.

The researchers found that people in both groups had a similar probability of experiencing clinical progression over time. For example, the cumulative probability of clinical worsening by two points or more on the EDSS scale over 12 months was 3.4% in both groups. Over 24 months, that probability was 5.4% in the ORATORIO group and 5.0% in the non-ORATORIO group. Interestingly, no significant differences in 12-month and 24-month clinically worsening were noted based on baseline EDSS score. People aged 56 to 65 years fared similarly to those aged 18 to 55 in terms of clinical status, but those aged 66 years and older were more likely than the ORATORIO group to experience clinical worsening over one or two years. Of course, this finding could reflect the interplay between the MS disease process and aging. Meanwhile, having had PPMS for more than 10 to 15 years did not appear to limit the impact of Ocrevus.

One of the key strategies in the fight against MS has been to determine the effectiveness and safety profile of a medication in a specific group of people and then explore whether that therapy also has a role in treating a broader population. This study by Italian researchers is both a classic example of that strategy succeeding and heartening news to many people living with PPMS.

The researchers studied 35 patients to explore how unmet needs, quality of life, and depression in older people with MS and in people with advanced MS differed from those of younger people with MS who were fully independent. Twenty-one people participating in the study were aged 64 or younger and did not require assistance with daily activities. These people served as the control group against which older people and those with an Expanded Disability Status Scale score of 7 or higher, indicating advanced MS, were compared.

While researchers noted that the better mental QoL among older people with MS relative to younger people was surprising, they did not offer potential explanations for the finding. They did say, however, that they plan to conduct future studies to look deeper into these results and to better understand the needs of older people with MS and people with advanced MS.

Aubagio® cuts risk of first demyelinating event in people with radiologically isolated syndrome

People with radiologically isolated syndrome (RIS) who took the disease-modifying therapy Aubagio® (teriflunomide) saw their risk for a first clinical demyelinating event reduced by 72% relative to people with RIS who received placebo in a 96-week study.10

The phase III randomized clinical trial was conducted from September 2017 to October 2019 at MS referral centers in France, Switzerland, and Turkey. The study involved 89 people, all of whom met the criteria for RIS, which the study’s authors noted is the earliest detectable preclinical phase of MS.

A person is classified as having RIS when magnetic resonance imaging (MRI) scans find white matter abnormalities consistent with MS in the brain or spinal cord even though the person has no clinical signs or symptoms of the disease. RIS often is identified when a person has an MRI for another reason, such as to evaluate the brain after a car accident or fall. Epidemiological studies indicate that as many as half of people with RIS will go on to be diagnosed with clinically definite MS over the following 10 years.

The study’s participants had an average age of 37.8 years. Seventy-one percent were female. Forty-five of the participants received 14 mg daily of Aubagio while the other 44 participants received a placebo. Nine people in each group stopped participating in the study for reasons that included adverse events, withdrawal of consent, lack of follow-up information, and pregnancy.

Researchers found that the unadjusted risk for a first clinical event in people receiving Aubagio was 63% lower than the risk for people in the placebo group. After adjusting for differences in the two groups in accord with standard statistical protocols, the people receiving Aubagio had a 72% lower risk relative to the placebo group.

The safety profile of Aubagio in the study was consistent with that seen in earlier studies of the oral DMT, which is approved by the FDA for treatment of relapsing forms of MS.

Learning that an MRI scan obtained for an unrelated reason shows evidence of a potential precursor to MS is disturbing enough, but the anxiety can be compounded by the fact that there currently is no FDA-approved therapy for RIS. This study, and others evaluating different DMTs for their potential use in RIS, provides hope that people diagnosed with the syndrome may have effective, evidence-based treatment options in the future.

Multi-protein blood test offers insights into MS disease activity

Clinicians may one day be able to use a multi-protein blood test to assess disease activity in a person with MS, including determining the likelihood of active inflammation in central nervous system lesions.

A team of researchers recently reported on their assessment of the MS Disease Activity (MSDA) test, which analyzes 18 proteins found in the blood.11 The researchers drew on blood samples, imaging results, and clinical data from 426 people with MS to develop an algorithm and establish performance specifications for the test.

The researchers then evaluated the test and its algorithm in a separate group of 188 people with MS. As part of that process, they compared the MSDA with the single-protein biomarker that they found to have the highest performance for different disease activity endpoints. Blood levels of that protein, neurofilament light chain (NfL), have been shown in a number of studies to help predict disease course in MS. (See related item below, “Predicting non-relapsing progression following anti-CD20 therapy for MS.”)

In “testing the test,” the investigators found that MSDA scores aligned well with overall disease activity and the presence of gadolinium-enhancing lesions on magnetic resonance imaging. (Gadolinium enhancement typically signifies inflammatory activity within an MS lesion.) For example, the odds of having one or more gadolinium-enhancing with a moderate/high disease activity (DA) score were 4.49 times those of a low DA score, the investigators reported. Further, the odds of having two or more such lesions with a high DA score were 21 times those of a low/moderate score. The researchers noted that the MSDA outperformed NfL in terms of identifying active versus stable MS as defined by a mix of imaging and clinical evidence.

The investigators wrote, “With the successful clinical validation of the MSDA Test, we envision several potential uses in the future, including a routine surveillance test to better monitor disease activity and progression (e.g., distinguish inflammation from silent disease progression), especially in patients considered to have stable disease, and to track new/worsening symptoms, as well as an evaluation test of treatment response, or in consideration of alternative treatment options.”

The MSDA is not yet available for use in clinical practice. The researchers noted that it would be valuable to further evaluate the test in a larger population and in a real-world setting. There also will be regulatory requirements to address, and payers must agree to provide reimbursement for the test. Nonetheless, the ability to draw on multiple proteins in the blood to assess various aspects of MS disease activity represents a major advance in the effort to evaluate and manage multiple sclerosis in a comprehensive manner.

Predicting non-relapsing progression following anti-CD20 therapy for MS

No news is not always good news when it comes to MS. That’s because disease progression can occur even in the absence of an obvious relapse or less-dramatic evidence of clinical worsening, making it difficult for clinicians and patients to know if a therapy is working or if a new approach may be warranted.

Now, however, researchers analyzing data from studies that led to the FDA’s approval of Ocrevus® (ocrelizumab) for relapsing and progressive forms of MS have found that blood levels of neurofilament light chain (NfL) can help predict non-relapsing progression following treatment with that therapy, which targets the CD20 protein on the surface of B cells.12

NfL is a protein found in axons, the segment of a neuron that carries electrical impulses away from the main portion of the nerve cell, facilitating transmission of those impulses from one neuron to another. When axons coated with myelin are injured, they release NfL into the cerebrospinal fluid. From there, the protein enters the blood stream. Most research on NfL has examined its role as a marker of acute events, such as relapses. In this study, however, investigators wanted to see whether NfL levels also could provide insights into more-subtle changes in MS course. They explained, “We used ocrelizumab’s ability to robustly suppress acute disease activity as an opportunity to assess the utility of NfL for monitoring risk for relapse-independent clinical progression following treatment initiation.”

The researchers analyzed baseline and subsequent blood levels of NfL in 1,421 people with relapsing MS and in 596 people with primary-progressive MS, evaluating more than 11,800 blood samples and following patients for as long as nine years.

And what did they find? Researchers found that long-term disability progression can still occur in the absence of observable disease activity, i.e., a relapse or clinical worsening, and elevated blood levels of NfL may predict the risk of such progression. In this study, after administration of Ocrevus, which suppressed relapse activity, patients who had persistently elevated levels of serum NfL at Week 24 and Week 48 were at increased risk of long-term disability progression. Researchers said this heightened risk was seen in both people with relapsing MS and those with primary-progressive MS.

The investigators concluded, “Suppression of relapsing biology with high-efficacy immunotherapy provides a window into the relationship between NfL levels and future non-relapsing progression.” This window can offer an important perspective not only on the management of individual patients but also into strategies for drug development.

Study shows no link between vaccination and hospitalization for MS flare-ups

People with MS who received one of several different types of vaccines were no more likely to be hospitalized for an MS flare-up in the 60 days after they were vaccinated than they were in the 60 days – or longer – before vaccination.

That was the main finding of a French study that examined records on more than 100,000 people with MS to investigate the common – but not scientifically supported – concern that vaccination may trigger MS flare-ups.13

Researchers analyzed an average of 8.8 years’ worth of data on the study subjects, 71.8% of whom were female. The people included in the analysis had an average age of 43.9 years. Roughly two-thirds had been diagnosed with MS for at least two years. Seventy percent had used at least one disease-modifying therapy.

Vaccines analyzed in the study included those for influenza, pneumococcal diseases, and diphtheria, tetanus, poliomyelitis, pertussis, and Haemophilus influenzae (the DTPPHi vaccine). All of the vaccines were inactivated, meaning that they did not contain live viral or bacterial material. Vaccines against COVID-19 were not included in the analysis because the period studied ran from January 2007 to December 2017, ending roughly two years before the coronavirus outbreak.

Of the 106,523 people studied, 35,265 – or one-third – were hospitalized for an MS flare-up on at least one occasion over the average 8+ years for which data was available on them. The adjusted odds ratio (aOR) of being hospitalized for an MS flare-up in the 60 days after receiving any one of the vaccines studied was 1.00. This means that a person was no more and no less likely to be hospitalized for an MS flare-up in the 60 days after vaccination than in the comparable period prior to vaccination. (By comparison, an aOR of 1.5 would represent a 50% increase in likelihood of hospitalization and a 2.0 aOR would represent a doubling of risk.)

Turning to specific vaccines, the aOR was 0.95 for the DTPPHi vaccine, 0.98 for the influenza vaccine, and 1.20 for the pneumococcal vaccine, which acts against the bacterium Streptococcus pneumoniae, and which can help prevent some cases of pneumonia, meningitis, and sepsis.

The investigators explained that, to their knowledge, their study is the most extensive research conducted to date on the risk of being hospitalized for an MS flare-up following vaccination. They added that examining this topic is essential because infections are known to increase the risk of MS flare-ups and to exacerbate symptoms, making it imperative that people with MS take steps – such as vaccination – to avoid infection. Further, they noted that “a possible association between vaccination and the onset of MS is the source of a decade-long debate,” adding that the inconclusive evidence and ongoing debate over that separate question “has spurred doubts and potentially detrimental vaccination hesitancy” among people who already have MS.

The researchers added that the strengths of their study included the large number of people in the analysis and the long follow-up period. Despite its size, however, the researchers noted that, “The study cannot completely rule out the existence of a small risk, particularly in the case of the pneumococcal vaccine.” They added, “considering the number of vaccine subtypes available, further studies are needed to confirm these observed results.”

While offering those important caveats, the researchers summed up their findings by noting, “We did not observe an association between the risk of hospitalization for an MS flare-up and vaccination, considered overall or individually, regardless of the age group studied.”

Guidelines from medical societies and multiple sclerosis advocacy organizations identify administration of inactivated vaccines as a key means of protecting the health of people with MS. The guidelines note that an individual should not receive a specific vaccine if he or she has a contraindication to it, and caution against giving vaccines while a person is experiencing an active flare-up of their MS.

With “flu” season fast approaching and an uptick in COVID-19 cases, it is important for people with MS to talk with their clinicians about which vaccines may be appropriate for them and about the risks and benefits associated with each vaccine. This large study hopefully will help to inform that discussion and provide some reassurance in terms of vaccination risk, which, of course, must be balanced against the risk that comes from not being vaccinated.

Pinpointing a way to relieve fatigue in MS? Study shows short-term benefits of acupuncture

Four weeks of acupuncture significantly relieved fatigue in an international study of 60 people with relapsing-remitting MS.14

All of the study participants reported fatigue, were not experiencing an MS exacerbation during the trial, and were given the medication amantadine. (In the United States, amantadine is approved by the FDA to prevent and treat influenza, to treat Parkinson’s disease and related conditions, and to treat movement problems that occur as side effects of certain medications. In other countries it also is used to treat MS-related fatigue, and some clinicians in the U.S. prescribe it “off-label” for that purpose.)

The study subjects were randomized into two groups of 30 people each. People in the first group received acupuncture treatment two to three times a week for a total of 10 sessions over four weeks. They also received 100 mg of amantadine daily, as well as whichever disease-modifying therapy (DMT) they were taking, if any. People in the other group took daily amantadine plus any DMT that had been prescribed for them. The study’s primary endpoint was change from baseline in the Fatigue Severity Score (FSS). The secondary endpoint was change from baseline in the Multiple Sclerosis Quality of Life 54 (MSQOL-54) questionnaire score.

Both groups saw their fatigue reduced over the course of the four-week study, but people in the acupuncture group had a greater reduction in fatigue than their counterparts in the control group. They also had greater improvement in their quality of life, including in both physical and mental status, than those in the control group. All of those differences were statistically significant. No adverse events were reported in either group.

In keeping with the adage that “everything old is new again,” the ancient practice of acupuncture – administered by properly trained and licensed personnel – may offer new hope to the estimated two-thirds of people with MS who experience fatigue.

Cannabinoid-based mouth spray relieves MS spasticity in two trials

People experiencing MS-related spasticity who made daily use of an oral spray containing cannabinoids experienced significant improvement in several measures of spasticity over 12 weeks, according to researchers.15

Those investigators analyzed results of two trials of nabiximols, a spray developed as a treatment for MS spasticity that is approved for use in European Union countries and elsewhere in the world, but which is not approved by the Food and Drug Administration for use in the United States. Nabiximols is a botanical mixture that contains delta-9-tetrahydrocannibinol (THC) and cannabidiol (CBD) from cannabis plants, as well as other non-cannabinoid ingredients.

Measures examined included patients’ daily self-reported scores from 0 to 10 on the Spasticity Numeric Rating Scale (NRS), patients’ daily spasm counts, and clinicians’ assessment of their patients’ spasticity using the modified Ashworth scale (MAS).

Both studies had an initial stage, Part A, in which all patients received nabiximols. Those who had a 20% or greater improvement in their Spasticity NRS score in Part A went on to the second stage, Part B, in which half of the people received nabiximols and half did not. Researchers use this two-step approach so they can first identify people who respond to a medication and then go on to study the impact of the medication relative to placebo only in a population of known responders. This can yield more valuable information on a medication than studying the therapy in a larger population in which the percentages of responders and non-responders are unknown at the outset.

In the first study, 124 people were randomly selected to use nabiximols, plus whatever other spasticity medicines or therapies they were receiving, while 117 people were randomized to receive placebo plus their current treatments, if any. The second study was limited to people who had not obtained adequate relief from two prior anti-spasticity medications and who were on current treatment for the condition. In that study, 53 people were randomized to receive nabiximols and 53 were assigned to the placebo group.

In Part B of both studies, participants receiving nabiximols had more favorable changes from baseline in their daily Spasticity NRS scores than their counterparts in the placebo group. Further, patients receiving nabiximols in the first study had a 19% greater reduction in daily spasms than people on placebo, while that difference stood at 35% in the second study. People receiving nabiximols also had better results in terms of change in spasticity as measured by the modified Ashworth scale, with the greatest benefits seen in the leg muscles.

The researchers reported that nabiximols were generally well tolerated by people in both studies. Urinary tract infections were the most frequently reported adverse events, affecting 7% of people receiving nabiximols in the first study. Other issues reported included vertigo, fatigue, nausea, dry mouth, dizziness, and sleepiness, with each condition affecting less than 10% of people receiving nabiximols There were six serious adverse events in the nabiximols group in the first study, while one person in that study’s placebo arm had a serious adverse event. In the second study, one patient in each group had a serious adverse event. In the first study, 7% of people in the nabiximols group stopped participating in the trial due to adverse events; none of the patients in the second study withdrew from the trial because of side effects.

Research has shown that a majority of people with MS are affected by spasticity. Many of those people report receiving insufficient relief from currently available therapies. This analysis of two studies suggests that another approach, not currently available, may someday help address a significant unmet need for people in America living with MS-related muscle spasms and stiffness.


  1. World Health Organization. WHO endorses landmark public health decisions on essential medicines for multiple sclerosis. July 26, 2023. Available at https://www.who.int/news/item/26-07-2023-who-endorses-landmark-public-health-decisions-on-essential-medicines-for-multiple-sclerosis. Accessed September 15, 2023.
  2. U.S. Food and Drug Administration (FDA). FDA approves first biosimilar to treat multiple sclerosis. August 24, 2023. Available at https://www.fda.gov/news-events/press-announcements/fda-approves-first-biosimilar-treat-multiple-sclerosis. Accessed September 15, 2023.
  3. Tremain, A.C., Wallace, R.P., Lorentz, K.M. et al. Synthetically glycosylated antigens for the antigen-specific suppression of established immune responses. Nat. Biomed. Eng 7, 1142–1155 (2023). [found at Synthetically glycosylated antigens for the antigen-specific suppression of established immune responses | Nature Biomedical Engineering]
  4. Wexler, M. ‘Inverse vaccine’ approach lowers disease in MS mouse model: ANK-700 is being tested in early MS clinical trials. Multiple Sclerosis News Today. September 14, 2023. Accessed online September 22, 2023 at MS disease activity in mice lowered with ‘inverse vaccine’ technique | Multiple Sclerosis News Today
  5. Williams, SCP. “Inverse vaccine” shows potential to treat multiple sclerosis and other autoimmune diseases. University of Chicago’s Pritzker School of Molecular Engineering (PME) News. September 11, 2023. Accessed online September 22, 2023 at  “Inverse vaccine” shows potential to treat multiple sclerosis and other autoimmune diseases | Pritzker School of Molecular Engineering | The University of Chicago (uchicago.edu)
  6. Nakamura K, Zheng Y, Ontandea D, et al. Effect of ibudilast on thalamic magnetization transfer ratio and volume in progressive multiple sclerosis. Mult Scler J. 2023;29(10). doi.org/10.1177/13524585231187289.
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  12. Bar-Or A, Thanei G-A, Harp C. Blood neurofilament light levels predict non-relapsing progression following anti-CD20 therapy in relapsing and primary progressive multiple sclerosis: findings from the ocrelizumab randomised, double-blind phase 3 clinical trials. EBioMedicine. 2023 Jul;93:104662. doi: 10.1016/j.ebiom.2023.104662.
  13. Grimaldi L, Papeix C, Hamon Y, et al. Vaccines and the risk of hospitalization for multiple sclerosis flare-ups. JAMA Neurol. Published online September 5, 2023. doi:10.1001/jamaneurol.2023.2968.
  14. Khodaie F, Moghadasi AN, Kazemi AH, Zhao B. Effectiveness of acupuncture for fatigue in patients with relapsing-remitting multiple sclerosis: a randomized controlled trial. Acupunct Med. 2023;41(4):199-205.
  15. Nicholas J, Lublin F, Klineova S, et al. Efficacy of nabiximols oromucosal spray on spasticity in people with multiple sclerosis: Treatment effects on Spasticity Numeric Rating Scale, muscle spasm count, and spastic muscle tone in two randomized clinical trials. Mult Scler Relat Disord. 2023;75.104745. doi.org/10.1016/j.msard.2023.104745.

For More Information

For general information or to speak with a trained Client Services Specialist, please call MSAA’s Helpline at (800) 532-7667, extension 154. Questions to MSAA’s Client Services department may also be emailed to MSquestions@mymsaa.org.

Written by Tom Garry, Medical Writer
Reviewed by Dr. Barry Hendin, MSAA Chief Medical Officer
Edited by Susan Wells Courtney, MSAA Senior Writer