Tag Archives: autologous

Detail, DMTsDetail, Treatment strategy

What are the attributes of the specific DMTs?

Multiple sclerosis (MS) treatment has evolved rapidly, with 11 classes of disease-modifying therapy (DMT) now available in the UK. I will summarise them briefly and explain how they fit within a treatment paradigm for effective and safe use.

Maintenance therapies versus immune reconstitution: what’s the difference?

There is a divide between the two main treatment philosophies: maintenance ̶ escalation versus immune reconstitution therapies (IRTs).

An IRT is given as a short course – a one-off treatment in the case of autologous haematopoietic stem cell transplantation (AHSCT) or intermittently for alemtuzumab, cladribine or mitoxantrone. IRTs are not given continuously, and additional courses are given only if inflammatory activity recurs. IRTs can induce long-term remission and, in some cases, potentially a cure.

Maintenance therapies, by comparison, are given continuously without an interruption in dosing (‘continuous’ administration may be daily, one or more times weekly, monthly or even once every few months). Although maintenance therapies can induce long-term remission, they cannot, by definition, result in a cure. The recurrence or continuation of inflammatory activity indicates a suboptimal response to treatment and typically requires a treatment switch. Ideally, this switch should be an escalation to a more effective class of DMT.

An article in our list of key questions, entitled How do I want my MS to be treated?, provides a more detailed comparison of maintenance and IRT therapies, including frequency of administration, efficacy, risks, use in pregnancy, vaccine response and potential for a cure.

The DMTs currently licensed in the UK (in August 2024) are listed in the table under the relevant category.

table format updated 180625 SS

Disease-modifying therapies for MS licensed in the UK. *Please note, Bonspri is available in other markets but not the UK.

How effective are the different DMTs?

The measures used to assess the effectiveness of a DMT include its ability to reduce or prevent relapses, focal inflammatory activity (that is, new or enlarging lesions) on magnetic resonance imaging (MRI), and disability progression. Additional factors that can help to assess the relative efficacy of DMTs include the proportion of clinical trial subjects who experience improvement in disability and the impact of the treatment on brain volume loss.

The MS-Selfie InfoCards are an easy-to-use resource to help people with MS compare the key features of each DMT. They contain bite-sized information designed to aid treatment choices and an overview of the key aspects of each DMT.

Efficacy of the licensed DMTs for MS can be visualised as pyramid, with the moderately effective treatments at the bottom and the more effective approaches at the top. What determines the most appropriate DMT efficacy level for an individual depends on several factors, such as baseline prognostic profile, family planning requirements, local or national treatment guidelines, socioeconomic factors, consideration of any co-existing illnesses, cognitive impairment, risk aversion and lifestyle issues.

Pyramid format updated 180625 SS

UK licensed DMTs for MS, in ascending order of efficacy.
HSCT/AHSCT, haematopoietic stem cell transplantation/autologous haematopoietic stem cell transplantation.

What is the goal of treatment? Introducing NEIDA as a target

In the past, we used no evident disease activity (NEDA) as a treatment target. ‘Disease activity’ included progression or disease worsening independent of relapse activity (termed smouldering MS). Although some of the more effective DMTs may modify this stage of the disease, many neurologists feel uncomfortable switching or stopping a DMT based simply on smouldering MS disease activity. 

Relapses and ongoing focal MRI activity are associated with a worse short-term to intermediate-term prognosis. These observations have led to the increasing adoption of ‘no evident inflammatory disease activity’ (NEIDA) as a new treatment target. For more information about treatment targets, please see the article in our key questions, Do I understand the concepts of treat-2-target and NEDA?

Many healthcare professionals (HCPs) remain sceptical of using NEIDA as a treatment target, fearing that this could lead to more people with MS being on ‘riskier’ high-efficacy therapies. However, achieving long-term remission, or NEIDA, is a well-established treatment target in other autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease. People with MS treated-to-target of NEIDA from the outset do better than those whose treatment is escalated following breakthrough disease (at a clinical or subclinical/MRI level)1. I would, therefore, strongly encourage people with MS and their HCPs to adopt NEIDA as an initial treatment target.

Flipping the pyramid

The effectiveness, or relative effectiveness, of individual DMTs becomes less critical in the context of a treatment target of NEIDA. Choosing a DMT with a lower efficacy rate simply means that a greater proportion of treated people with MS will need to be switched to higher efficacy therapies over time to achieve NEIDA. We refer to the latter of these three approaches – starting with high-efficacy treatment – as flipping the pyramid. In recent trials of alemtuzumab, ocrelizumab, ofatumumab and ublituximab, people with MS randomised to 2 years of lower efficacy DMTs (interferon-beta-1a or teriflunomide) had poorer outcomes than those receiving highly active therapy from the outset. Real-world data from registries also support this; groups of people with MS with delayed access to high-efficacy DMTs did worse than those who received high-efficacy treatments early.1,2

Horizontal versus vertical switching

If we consider the conventional step care paradigm, people with MS who switch horizontally from interferon-beta to glatiramer acetate, or vice-versa (i.e. from one moderate efficacy DMT to another moderate efficacy DMT) do less well than those who switch vertically to fingolimod, a highly effective DMT. Similarly, people with MS escalating to natalizumab, a very high-efficacy DMT, do better than those being escalated to the less effective, but still high-efficacy, DMT fingolimod. 

Continuous and intermittent immunosuppression

Another useful way of classifying DMTs is whether they are immunosuppressive, that is, they reduce the activation, or effectiveness, of the immune system. Drug regulators stipulate that a drug may be classified as immunosuppressive if it (1) causes significant lymphopaenia (low lymphocyte count) or leukopenia (low white blood cell count), (2) is associated with opportunistic infections, (3) reduces the antibody and immune response to vaccines and (4) increases the risk of secondary malignancies.

The duration and intensity of immunosuppression further determine the risks. For example, short-term or intermittent immunosuppression associated with IRTs front-loads the risks, which are substantially lower once the immune system has reconstituted itself. In comparison, long-term continuous or persistent immunosuppression, which occurs with some of the maintenance DMTs, accumulates problems over time, particularly opportunistic infections and secondary malignancies. You can read more detail on this topic in the key question How immunosuppressed am I? The following table summarises the main attributes of intermittent and persistent immunosuppression.

How immunosuppressed are you table updated format 180625 SS

The main characteristics of continuous (persistent) and short-term (intermittent) immunosuppression. Modified from Giovannoni, Curr Opin Neurol.2
AHSCT, autologous haematopoietic stem cell transplantation; PML, progressive multifocal leukoencephalopathy.

Adverse effects, monitoring and risk reduction

The complications associated with immunosuppression vary from DMT to DMT. Each individual drug summary in the DMTs section of MS-Selfie contains detailed information about the main adverse events, key monitoring requirements, use (or contraindication) during pregnancy and breastfeeding, and response to vaccines. The MS-Selfie InfoCards provide bite-sized summaries of several practical aspects, including side effects, to enable easy comparison of any treatments you are considering; some of this information is collated below for easy reference.

Short-term versus long-term adverse effects

Each drug has been given scores from 1 to 10 based on published analyses of its short-term and long-term side effects. Short-term refers to side effects that emerge when a treatment is started and decrease in severity or disappear within days or weeks. A well-known example of short-term side effects on starting interferon-beta is flu-like symptoms that typically abate within 4 ̶ 8 weeks.

A long-term side effect persists for months or doesn’t disappear on continuing the DMT. Examples include intermittent but persistent flushing after taking dimethyl fumarate, or low B lymphocyte counts with anti-CD20 therapies that may lead to low antibody or immunoglobulin levels (hypogammaglobulinaemia).

A low score denotes few or rare side effects; a high score denotes many or frequent side effects. The score does not correlate to a percentage. More information can be found in each drug summary and the manufacturer’s Summary of Product Characteristics.

Scores for short-term and long-term side effects assigned to the individual DMTs summarised in the MS-Selfie InfoCards, based on a published network meta-analysis.3
Alem, alemtuzumab; GA, glatiramer acetate; HSCT, haematopoietic stem cell transplantation; IFN-beta; interferon-beta; Nat, natalizumab.

Monitoring and risk reduction

Numerous tests are carried out at the start of treatment, and ongoing monitoring is required for many factors, to reduce the risk from adverse events. The key question, How can I reduce my chances of adverse events on specific DMTs?, explains what needs to be done at the start of DMT administration (baseline) and during subsequent monitoring. The specifics vary from DMT to DMT; please refer to the individual summaries for details such as baseline tests, follow-up, infection prevention, cancer risk, pregnancy, breastfeeding and vaccination. It is important to remember that all licensed MS DMTs have had a thorough risk ̶ benefit assessment, and their benefits are considered to outweigh the potential risks.

Administration and other practical considerations

Routes and frequency of administration

The MS-Selfie InfoCards contain a symbol for each DMT, showing how it is administered. Some DMTs are available in more than one formulation (e.g. tablets and injection). The frequency of administration varies greatly from DMT to DMT; please consult the relevant summary in the DMTs section and discuss your preferences and priorities with your MS HCP.

The route of administration for each drug in the MS-Selfie InfoCards is clearly identified by the relevant symbol. (If a DMT is available in more than one formulation, there is a separate card for each delivery route.)

Number of clinic visits

It may be important for you to consider the frequency of clinic visits. This will depend on factors such as the delivery route of your DMT, the monitoring requirements of the drug regulators and the risk of specific side effects. The table below summarises the assessments from the MS-Selfie InfoCards. This is another factor to consider in discussions with your MS HCPs about the most appropriate DMT for you.

Conclusions

People with MS must understand the objectives of MS treatments and the different treatment strategies currently available to achieve these objectives. Although the MS therapeutic landscape is complex and hence may seem overwhelming, framing the choices using a relatively simple construct should help each individual to make informed decisions about managing their MS. MS-Selfie aims to guide you in the process of deciding on the most appropriate therapeutic strategy and specific DMT for treating your disease.

References

  1. Rotstein D, et al. Association of No Evidence of Disease Activity with no long-term disability progression in multiple sclerosis: a systematic review and meta-analysis. Neurology 2022;99:e209̶ ̶ 20.
  2. Giovannoni G. Disease-modifying treatments for early and advanced multiple sclerosis: a new treatment paradigm. Curr Opin Neurol 2018;31:233 ̶ 43.
  3. Samjoo IA, et al. Efficacy classification of modern therapies in multiple sclerosis. J Comp Eff Res 2021;10:495–507.
Pregnancy and childbirth, Women's health

Planning for pregnancy

This article discusses the effects of MS on fertility, decisions about starting or stopping a DMT, the use and safety of oral contraceptives and the possible impact of in vitro fertilisation on MS disease course.

Does MS affect my fertility?

No, MS does not affect fertility. Women and men with MS are as fertile as people without MS. However, MS does not protect women and men from other causes of infertility. Fertility treatment may impact MS (see below). Please be aware that mitoxantrone, AHSCT (autologous haemopoietic stem cell treatment) and other chemotherapy treatments, such as cyclophosphamide used off-label to treat MS, may be toxic to ovarian and testicular function and require egg and sperm banking before treatment.

Should I go onto a DMT and get my MS under control before starting a family or first start my family?

In general, I recommend that women with active MS delay pregnancy until their disease is under control, optimise their general health and prepare properly for becoming a parent. There is no point in having active MS, not starting a DMT and having a catastrophic relapse in the period during which you are trying to fall pregnant.

However, a desire to start or extend your family should not change the way you want your MS managed. Early effective treatment, treating to a target of NEIDA, potentially flipping the pyramid, preventing end-organ damage and the holistic management of MS are all compatible with pregnancy. There are no rules for implementing this strategy in pregnancy because all decisions should be personalised. For example, a woman with rapidly evolving severe MS may choose natalizumab and stay on it throughout pregnancy and while breastfeeding because her MS was so active and potentially devastating. Another woman who is young, risk adverse and with a very good prognosis may choose to delay starting a DMT until she has had a child. Yet another woman, diagnosed at 40, may not want to delay falling pregnant and may opt for a DMT that is safe during pregnancy.

It is up to the person with MS, their partner and sometimes their extended family to make the final decisions about how to manage their MS during pregnancy. The healthcare professional (HCP) is there to provide information and guidance in this process.

Are oral contraceptives safe in people with MS?

To my knowledge, contraceptives are safe and effective in women with MS. The same contraindications and relative contraindications to specific contraceptives apply to women with MS as to the general population. Hormonal contraceptives are associated with an increased risk of thrombosis; women with MS who are immobile thus have a higher risk of deep vein thrombosis than those who are mobile.

Which contraceptive would you recommend?

MS should not be the deciding factor around the choice of contraceptive unless the degree of MS-related disability makes managing menstrual hygiene difficult. In this case, contraceptives that suppress menstruation have advantages, for example, continuous hormonal contraceptives or the progestin-tipped intrauterine contraceptive device (Mirena).

Inclusion criteria for participation in specific drug trials sometimes mandate double contraception, for example, a hormonal contraceptive and a barrier method. This is to try and avoid accidental pregnancies while taking an investigational compound without a safety track record in humans.

How long before I fall pregnant must I stop my DMT?

It depends on which DMT you are taking. Only the DMTs that are teratogenic or potentially teratogenic (i.e., may cause foetal malformations) need to be stopped before you fall pregnant. It is essential to allow sufficient time for these agents to be eliminated from the body.

Teriflunomide

Teriflunomide has the potential to cause birth defects; therefore, patients must have effective contraception whilst on this treatment. It has a very long half-life because it is reabsorbed in the intestine and is eliminated slowly from the plasma. Without an accelerated elimination procedure, it takes up to 8 months to reach plasma concentrations of less than 0.02 mg/l, which are considered safe. Remarkably, due to individual variations in teriflunomide clearance, it may take up to 2 years to fall to acceptable levels. An accelerated elimination procedure with cholestyramine or activated charcoal can be used at any time after the discontinuation of teriflunomide.

Teriflunomide accelerated elimination procedure

After stopping treatment with teriflunomide:

• Cholestyramine 8 g is administered three times daily for 11 days, or cholestyramine 4 g three times a day can be used if cholestyramine 8 g three times a day is not well tolerated.

• Alternatively, 50 g of activated powdered charcoal is administered every 12 hours for 11 days.

Following either of the accelerated elimination procedures, it is recommended to verify elimination by checking teriflunomide blood levels and allow a waiting period of 1.5 months between the first occurrence of a plasma concentration below 0.02 mg/l and planned fertilisation.

S1P modulators

S1P modulators are contraindicated during pregnancy, owing to the risk to the foetus. Before starting treatment in women of childbearing potential, we do a urine pregnancy test. Women taking an S1P modulator must use effective contraception during treatment and then continue for:

  • 2 months after stopping treatment with fingolimod (Gilenya)
  • 10 days after stopping treatment with siponimod (Mayzent)
  • 3 months after stopping treatment with ozanimod (Zeposia)
  • 7 days after stopping treatment with ponesimod (Ponvory).

Stopping the S1P modulators brings the potential for rebound disease activity, so most neurologists now prefer to transition women on one of these therapies to another class of DMT that is considered safer in pregnancy.

Safer options

Safer options during pregnancy include an injectable (interferon-beta or glatiramer acetate), a fumarate, an anti-CD20 therapy, natalizumab or an immune reconstitution therapy (cladribine or alemtuzumab). I cover some of the issues related to anti-CD20 therapies in the MS-Selfie case study ‘Wait to fall pregnant or start a DMT now?’.

The good news is that several DMT options are now available to women with MS wanting to fall pregnant.

Can I have IVF, and what will IVF do to my MS?

There is no reason why a person with MS cannot have IVF (in vitro fertilisation). However, there appears to be a slightly increased risk of relapse after IVF and egg harvesting. Whether this is due to stopping DMTs before undergoing IVF or due to the drugs used to stimulate ovulation is unknown. Studies reporting an increase in disease activity after IVF are more likely to be published than studies not showing such an increase so that publication bias may affect the findings. I recommend viewing IVF as a planned pregnancy and giving women with MS the option of receiving a DMT that is relatively safe in pregnancy or treating their MS with immune reconstitution therapy before IVF.

References

Krysko KM et al. Treatment of women with multiple sclerosis planning pregnancy. Curr Treat Options Neurol 2021;23:11.

Other articles in this series on Pregnancy and childbirth:
Managing MS during pregnancy
Preparing to give birth
Breastfeeding if you are on a DMT
Concerns about parenting

DMTs, Treatment strategy

How immunosuppressed am I?

Do you understand the difference between short-term intermittent and long-term continuous immunosuppression? Here we address another of the key questions to consider before deciding on a specific disease-modifying therapy (DMT).

Key points

  • Immunosuppressive disease-modifying therapies (DMTs) reduce the immune system’s effectiveness.
  • It is important to weigh up the benefits and risks of short-term versus continuous immunosuppression.
  • Non-selective DMTs suppress the adaptive and innate immune systems; selective DMTs do not affect the innate immune system and are thus associated with a low risk of bacterial infections.
  • The implications of immunosuppression need to be considered within the context of other health and lifestyle factors.

Which DMTs cause immunosuppression?

A useful way of thinking about DMTs is based on whether they are immunosuppressive. Broadly speaking, an immunosuppressive is any DMT that reduces the immune system’s activation or effectiveness. 

From a regulatory perspective, for a drug to be classified as immunosuppressive, it should: 

  • cause significant lymphopaenia or leukopenia (reduced white cell counts)
  • be associated with opportunistic infections (infections that don’t occur in people with a normal, healthy immune system)
  • reduce antibody and/or T-cell responses to vaccines 
  • increase the risk of secondary malignancies. 

Based on the above criteria, the interferon-beta preparations and glatiramer acetate are immunomodulatory rather than immunosuppressive. Teriflunomide is also an immunomodulatory therapy with the potential, albeit small, to cause immunosuppression. In real life, however, very few people with MS treated with teriflunomide develop significant lymphopaenia or leukopenia; if they do, we tend to stop the drug. The other licensed DMTs are immunosuppressive to a greater or lesser degree. 

Short-term versus continuous immunosuppression

The duration and intensity of immunosuppression further determine the risks. Short-term or intermittent immunosuppression associated with an immune reconstitution therapy (IRT) front-loads the risks, which decrease substantially once the immune system has reconstituted itself. In comparison, long-term continuous or persistent immunosuppression, which occurs with most maintenance DMTs, accumulates problems over time, particularly opportunistic infections and secondary malignancies.

Live vaccines are, in general, contraindicated in patients on continuous immunosuppressive therapies. However, someone with MS on an IRT who has reconstituted their immune system can tolerate and respond to live vaccines. The benefits of administering live vaccines always need to be balanced against the risks of the vaccine.

How immunosuppressed are you table updated format 180625 SS

The main characteristics of continuous persistent and short-term (intermittent) immunosuppression. Modified from Giovannoni, Curr Opin Neurol.1
AHSCT, autologous haematopoietic stem cell transplantation; PML, progressive multifocal leukoencephalopathy.

Selective versus non-selective immunosuppression

Immunosuppression that accompanies DMTs may be selective or non-selective. Non-selective therapies deplete and/or suppress both the adaptive immune system (T cells and B cells) and the innate immune system (monocytes, neutrophils and natural killer [NK] cells). Alemtuzumab, AHSCT (autologous haematopoietic stem cell transplantation) and mitoxantrone are non-selective and are therefore associated with acute bacterial infections such as listeriosis, nocardiosis and cytomegalovirus reactivation. In comparison, anti-CD20 agents (ocrelizumab and ofatumumab) and cladribine are selective, do not affect the innate immune system and are therefore associated with a low risk of acute bacterial infections. 

How immunosuppressed are you_MET vs IRT_2 Dec 2024

Classification of disease-modifying therapies for relapsing forms of MS. Modified from Giovannoni, Curr Opin Neurol.1
AHSCT, autologous haematopoietic stem cell transplantation.

Other considerations

Please note that the implications of immunosuppression are not black and white but interact with other factors such as:

These factors have been highlighted during the COVID-19 pandemic, particularly in relation to the risk of severe COVID-19 and the variations in vaccine responses among people with MS (including waning of the immune response).

It is important to realise that we can derisk (reduce the risk of) some complications associated with long-term immunosuppression and the use of DMTs. Please see the post entitled How can I reduce my chances of adverse events on specific DMTs?

References

  1. Giovannoni G. Disease-modifying treatments for early and advanced multiple sclerosis: a new treatment paradigm. Curr Opin Neurol 2018;31:233 ̶ 43.
DMTs, Treatment strategy

How do I want my MS to be treated?

What is the difference between a maintenance ̶ escalation DMT and an immune reconstitution therapy (IRT)? Why is it important to understand the distinction?

Key points

  • Maintenance–escalation and immune reconstitution therapy (IRT) are two approaches to MS treatment currently favoured.
  • IRT is a one-off, short course which acts on immune system cells in three stages: reduction, repopulation and reconstitution.
  • Maintenance–escalation is given continuously without interruption. If it does not work well, the treatment is changed to a more effective DMT (known as ‘escalation’).
  • Additional future approaches are likely to include induction ̶ maintenance and/or combination therapy.

If I had MS, how would I want to be treated? This is a difficult question, and one that many of my patients ask me. The answer depends on your life stage, what risks you are prepared to take, personal factors such as family planning considerations and the extent of your understanding of MS and how we approach its treatment.

Currently, there are two main philosophies regarding the treatment of MS with DMTs: maintenance/escalation versus immune reconstitution therapies (IRTs). 

What is an immune reconstitution therapy?

By definition, an IRT is given as a short course, i.e. as a one-off treatment in the case of autologous haematopoietic stem cell transplantation (AHSCT) or intermittently in the case of alemtuzumab, cladribine or mitoxantrone. IRTs are not given continuously, and additional courses of the therapy are given only if there is a recurrence of MS inflammatory activity. IRTs can induce long-term remission and, arguably, in some cases a potential cure.

IRTs have three phases to their mode of action, which I refer to as the ‘three Rs’.

  1. Reduction, or depletion, when we try to kill the autoimmune cells that cause MS.
  2. Repopulation, when the immune system recovers from stem cell transplantation and, hopefully, the autoimmune cells don’t return.
  3. Reconstitution, when the immune system is recovered and fully competent. The recovered immune system following treatment with an IRT is different from what was there before. Some people like to think of an IRT as a reboot of the immune system, but without MS.
Slide1

The three Rs of immune reconstitution therapy: reduction, repopulation and reconstitution. From Giovannoni, Curr Opin Neurol.1 

What is an MS ’cure’?

One attempt at a definition describes an MS cure as no evidence of disease activity (NEDA) 15 years after the administration of an IRT. I justify using 15 years because it is the time-point most accepted for defining ‘benign MS‘ and is also beyond the average time to onset of secondary progressive MS in natural history studies.

What is a maintenance therapy?

A maintenance therapy is given continuously without an interruption in dosing. Although maintenance therapies can induce long-term remission (i.e. NEDA), they cannot result in a cure. The recurrence or continuation of inflammatory disease activity with maintenance therapies is an indication of a suboptimal response to treatment and typically results in a treatment switch. Ideally, this switch should be to a more effective class of DMTs – hence the term ‘escalation’. 

What would I recommend?

I can’t choose for you. The debate is complex and depends on many factors. One important consideration is vaccine readiness: will I be able to mount an adequate immune response to a vaccine? IRTs have the advantage that they allow reconstitution of the immune system; once it recovers, vaccine responses are restored, and even live vaccines can be given.

The table below highlights key differentiators. Further, detailed information about most of the products listed in the Table can be accessed through the DMT comparison tool available at ClinicSpeak or via the Multiple Sclerosis Trust MS Decisions aid.

Similarities and differences between maintenance treatments and immune reconstitution therapies. Registered trade names (UK market) of the generic drugs listed are shown in brackets. *How to define a ‘cure’ in MS is controversial. Modified from Giovannoni, Curr Opin Neurol.1
DMT, disease-modifying therapy; HSCT, haematopoietic stem cell transplant; IRT, immune reconstitution therapy.

The future

I envisage two more treatment strategies emerging.

  • One approach is induction ̶ maintenance therapy, using an IRT followed by an immunomodulatory therapy rather than an immunosuppressive DMT (which is a safer option) the aim is to keep MS in long-term remission. This approach is used in oncology, where the cancer is hit hard with induction chemotherapy and then kept at bay with a well-tolerated maintenance therapy (e.g. antihormonal therapies in breast cancer).
  • Another approach is combination maintenance therapy; the aim would be to combine an anti-inflammatory therapy with, say, neuroprotective therapies to target smouldering MS.

The diagram below illustrates the scheduling of the four approaches discussed in this section. You may like to try out the DMT comparison tool to find out how some of the drugs listed in the comparison Table above align with your personal life choices and priorities.

Slide5

Four approaches discussed in this section. The white panels illustrate the two approaches currently available; the shaded panels illustrate two strategies that may emerge in the future. Modified from Giovannoni, Curr Opin Neurol.1

References

  1. Giovannoni G. Disease-modifying treatments for early and advanced multiple sclerosis: a new treatment paradigm. Curr Opin Neurol 2018;31:233 ̶ 43.