An Overview of High-Efficacy Drugs for Multiple Sclerosis: Gulf Region Expert Opinion

Practical Recommendations from the Gulf Region on the Therapeutic Use of Cladribine Tablets for the Management of Relapsing Multiple Sclerosis: Impact of the Latest Real-World Evidence on Clinical Practice

Cladribine tablets (CladT), like alemtuzumab, acts as an immune reconstitution therapy. However, CladT is administered orally (alemtuzumab is given by infusion) and without the potential for serious side effects that limit the therapeutic use of alemtuzumab in multiple sclerosis (MS). Treatment with CladT, given initially as short courses of treatment 1 year apart, provides years of freedom from MS disease activity in responders to treatment. The appearance of mild or moderate MS disease activity after the initial 2 years of treatment may prompt careful follow-up or a further course of CladT, depending on the nature of the activity and individual circumstances. The appearance of severe MS disease activity requires a switch to an alternative high-efficacy disease-modifying treatment (DMT). The accumulating data from CladT-treated people with MS in real-world studies, including those with follow-up durations extending for years beyond the initial treatment, have demonstrated long-term freedom from MS disease activity in a good proportion of patients. This clinical experience has also confirmed that treatment with CladT is generally safe and well tolerated. The best time to prescribe a high-efficacy DMT is the subject of debate, with evidence that earlier versus later use of such agents may provide more effective long-term protection from disability progression. High-efficacy DMTs have traditionally been reserved for use in people with MS and high disease activity on presentation or breakthrough disease on one or more DMTs, as per the current product labels. The latest evidence from real-world studies suggests that CladT is effective and safe in DMT-naïve patients, including those with shorter disease duration.

Holistic, Long-Term Management of People with Relapsing Multiple Sclerosis with Cladribine Tablets: Expert Opinion from France

Cladribine tablets (CladT) has been available for therapeutic use in France since March 2021 for the management of highly active relapsing multiple sclerosis (RMS). This high-efficacy disease-modifying therapy (DMT) acts as an immune reconstitution therapy. In contrast to most high-efficacy DMTs, which act via continuous immunosuppression, two short courses of oral treatment with CladT at the beginning of years 1 and 2 of treatment provide long-term control of MS disease activity in responders to treatment, without the need for any further pharmacological treatment for several years. Although the labelling for CladT does not provide guidance beyond the initial treatment courses, real-world data on the therapeutic use of CladT from registries of previous clinical trial participants and patients treated in routine practice indicate that MS disease activity is controlled for a period of years beyond this time for a substantial proportion of patients. Moreover, this clinical experience has provided useful information on how to initiate and manage treatment with CladT. In this article we, a group of expert neurologists from France, provide recommendations on the initiation of CladT in DMT-naïve patients, how to switch from existing DMTs to CladT for patients with continuing MS disease activity, how to manage patients during the first 2 years of treatment and finally, how to manage patients with or without MS disease activity in years 3, 4 and beyond after initiating treatment with CladT. We believe that optimisation of the use of CladT beyond its initial courses of treatment will maximise the benefits of this treatment, especially early in the course of MS when suppression of focal inflammation in the CNS is a clinical priority to limit MS disease progression.

Narrative Review on the Use of Cladribine Tablets as Exit Therapy for Stable Elderly Patients with Multiple Sclerosis

The number of ageing people with relapsing multiple sclerosis (RMS) is increasing. The efficacy of disease-modifying therapies (DMTs) for RMS declines with age. Also, older persons with MS may be more susceptible to infections, hospitalisations and malignancy. Aging people with MS have higher rates of comorbidities versus aged-matched controls, increasing the individual risk of disability. We review the therapeutic properties of cladribine tablets (CladT) in ageing people with RMS, with regard to their utility for allowing these individuals to cease continuous administration of a DMT (i.e. to act as an "exit therapy"). CladT is thought to be an immune reconstitution therapy, in that two short courses of oral treatment 1 year apart provide suppression of MS disease activity in responders that far outlasts the duration of treatment and post-treatment reductions in lymphocyte counts. Post hoc analyses, long-term follow-up of populations with RMS in randomised trials, and real-world evidence suggest that the efficacy of CladT is probably independent of age, although more data in the elderly are still needed. No clear adverse signals for lymphopenia or other adverse safety signals have emerged with increasing age, although immunosenescence in the setting of age-related "inflammaging" may predispose elderly patients to a higher risk of infections. Updating vaccination status is recommended, especially against pneumococci and herpes zoster for older patients, to minimise the risk of these infections. CladT may be a useful alternative treatment for ageing people with MS who often bear a burden of multiple comorbidities and polypharmacy and who are more exposed to the adverse effects of continuous immunosuppressive therapy.

Substantial and comparable suppression of disease activity following early initiation of cladribine tablets, ocrelizumab or alemtuzumab as first pharmacologic treatment for relapsing multiple sclerosis: A real world study

BACKGROUND

We describe the efficacy and safety of recent high efficacy disease DMTs in DMT-naive patients with highly active RMS.

METHODS

This was a retrospective, cross sectional study from the Kuwait national MS registry. Patients with RMS who received alemtuzumab, cladribine tablets or ocrelizumab as their first DMT for RMS, with ≥2 year of follow up were included. The primary endpoint was the change in relapse rate from treatment initiation to 1 year; changes in disability (Expanded Disability Status Scale [EDSS]), radiologic activity, the proportion with no evidence of disease activity-3 (NEDA-3), and the frequency of adverse events were secondary endpoints.

RESULTS

Among 123 RRMS patients, 59 received ocrelizumab, 32 received cladribine tablets and 32 received alemtuzumab. About two-thirds (65%) were women. Substantial and similar (p>0.05) reductions occurred at the end of follow-up in annual relapse rate (by 93.2% for ocrelizumab, 87.5% for cladribine tablets, and 90.6% for alemtuzumab). The proportion with new T2 of gadolinium-enhancing MRI lesions across the three groups was reduced from 85-100% to 7-13%. Rates of confirmed disability progression were low (ocrelizumab 6.9%, cladribine tablets 3.1%, alemtuzumab 0%; p=0.280); disability was reduced in 15%, 22% and 38%, respectively. NEDA-3 was observed in 89.8%, 87.5%, and 84.4, respectively (p=0.784). No new or unexpected safety issues occurred.

CONCLUSION

Ocrelizumab, cladribine tablets and alemtuzumab reduced relapse rates and MRI activity, and prevented disease progression, when are initiated early in DMT-naive RMS patients. These data support the early use of high-efficacy DMTs for people with highly active RMS.

Expert Narrative Review of the Safety of Cladribine Tablets for the Management of Relapsing Multiple Sclerosis

Cladribine tablets (CladT) is a highly active oral disease-modifying therapy (DMT) for the management of relapsing multiple sclerosis (RMS). CladT acts as an immune reconstitution therapy, in that two short courses of treatment 1 year apart have been shown to suppress disease activity for a prolonged period in most patients, without need for continued DMT. Each course of CladT induces a profound reduction in B lymphocytes that recovers over months, and serious lymphopenia (Grade 3-4) is uncommon. Smaller reductions in levels of T lymphocytes occur slightly later: on average, these remain within the normal range and repopulate progressively. A larger effect occurs on CD8 vs. CD4 cells. Reactivation of latent or opportunistic infections (e.g. varicella zoster, tuberculosis) is mostly associated with very low lymphocyte counts (< 200/mm3). Screening and managing pre-existing infections, vaccinating non-exposed patients and delaying the 2nd year of treatment with CladT to allow lymphocytes to recover to > 800/mm3 (if necessary) are important for avoiding infections and higher-grade lymphopenia. There was no demonstrable or apparent effect of CladT on the efficacy of vaccinations, including against Covid-19. Adverse events consistent with drug-induced liver injury (DILI) represent a rare but potentially serious complication of CladT therapy in spontaneous adverse event reporting; patients should be screened for liver dysfunction before starting treatment. Ongoing hepatic monitoring is not required, but CladT must be withdrawn if signs and symptoms of DILI develop. There was a numerical imbalance for malignancies when comparing cladribine to placebo in the clinical programme, particularly in short-term data, but recent evidence shows that the risk of malignancy with CladT is similar to the background rate in the general population and to that with other DMTs. Overall, CladT is well tolerated with a favorable safety profile appropriate for the management of RMS.

Multicentre Observational Study of Treatment Satisfaction with Cladribine Tablets in the Management of Relapsing Multiple Sclerosis in the Arabian Gulf: The CLUE Study

INTRODUCTION

Inconvenient administration and side effects of some disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) can deter adherence. We evaluated treatment satisfaction with cladribine tablets (CladT) for RMS in the Arabian Gulf.

METHODS

This was a non-interventional, multicentre, prospective observational study in non-pregnant/lactating adults (aged ≥ 18 years) with RMS eligible for 1st treatment with CladT (EU labelling). The primary outcome was overall treatment satisfaction at 6 months (Treatment Satisfaction Questionnaire for Medication [TSQM]-14, v. 1.4), Global Satisfaction subscale. Secondary endpoints were TSQM-14 scores for convenience, satisfaction with side effects and satisfaction with effectiveness. Patients provided written informed consent.

RESULTS

Of 63 patients screened, 58 received CladT and 55 completed the study. Mean age was 33 ± 9 years; mean weight 73 ± 17 kg; 31% male/69% female; mostly from the United Arab Emirates (52%) or Kuwait (30%). All had RMS (mean 0.9 ± 1.1 relapses in the past year), mean Expanded Disability Status Scale (EDSS) 1.4 ± 1.2; 36% were DMT-naïve. Mean [95% CI] score was high for overall treatment satisfaction (77.8 [73.0-82.6]), ease of use (87.4 [83.7-91.0]), tolerability (94.2 [91.0-97.3]) and effectiveness (76.2 [71.6-80.7]). Scores were similar irrespective of DMT history, age, gender, relapse history or EDSS. No relapses or serious treatment-emergent adverse events (TEAE) occurred. Two severe TEAE occurred (fatigue, headache) and 16% reported lymphopenia (two cases of grade 3 lymphopenia). Absolute lymphocyte counts at baseline and 6 months were 2.2 ± 0.8 × 109/L and 1.3 ± 0.3 × 109/L, respectively.

CONCLUSIONS

Treatment satisfaction, ease of use, tolerability and patient-perceived effectiveness for CladT were high, irrespective of baseline demographics, disease characteristics and prior treatment.

The Place of Immune Reconstitution Therapy in the Management of Relapsing Multiple Sclerosis in France: An Expert Consensus

The treatment strategy in relapsing multiple sclerosis (RMS) is a complex decision requiring individualization of treatment sequences to maximize clinical outcomes. Current local and international guidelines do not provide specific recommendation on the use of immune reconstitution therapy (IRT) as alternative to continuous immunosuppression in the management of RMS. The objective of the program was to provide consensus-based expert opinion on the optimal use of IRT in the management of RMS. A Delphi method was performed from May 2022 to July 2022. Nineteen clinical assertions were developed by a scientific committee and sent to 14 French clinical experts in MS alongside published literature. Two consecutive reproducible anonymous votes were conducted. Consensus on recommendations was achieved when more than 75% of the respondents agreed or disagreed with the clinical assertions. After the second round, consensus was achieved amongst 16 out of 19 propositions: 13 clinical assertions had a 100% consensus, 3 clinical assertions a consensus above 75% and 3 without consensus. Expert-agreed consensus is provided on topics related to the benefit of the early use of IRT from immunological and clinical perspectives, profiles of patients who may benefit most from the IRT strategy (e.g. patients with family planning, patient preference and lifestyle requirements). These French expert consensuses provide up-to-date relevant guidance on the use of IRT in clinical practice. The current program reflects status of knowledge in 2022 and should be updated in timely manner when further clinical data in IRT become available.

Comparing switch to ocrelizumab, cladribine or natalizumab after fingolimod treatment cessation in multiple sclerosis

BACKGROUND

To compare the effectiveness and treatment persistence of ocrelizumab, cladribine and natalizumab in patients with relapsing-remitting multiple sclerosis switching from fingolimod.

METHODS

Using data from MSBase registry, this multicentre cohort study included subjects who had used fingolimod for ≥6 months and then switched to ocrelizumab, cladribine or natalizumab within 3 months after fingolimod discontinuation. We analysed relapse and disability outcomes after balancing covariates using an inverse-probability-treatment-weighting method. Propensity scores for the three treatments were obtained using multinomial-logistic regression. Due to the smaller number of cladribine users, comparisons of disability outcomes were limited to natalizumab and ocrelizumab.

RESULTS

Overall, 1045 patients switched to ocrelizumab (n=445), cladribine (n=76) or natalizumab (n=524) after fingolimod. The annualised relapse rate (ARR) for ocrelizumab was 0.07, natalizumab 0.11 and cladribine 0.25. Compared with natalizumab, the ARR ratio (95% confidence interval [CI]) was 0.67 (0.47 to 0.96) for ocrelizumab and 2.31 (1.30 to 4.10) for cladribine; the hazard ratio (95% CI) for time to first relapse was 0.57 (0.40 to 0.83) for ocrelizumab and 1.18 (0.47 to 2.93) for cladribine. Ocrelizumab users had an 89% lower discontinuation rate (95% CI, 0.07 to 0.20) than natalizumab, but also a 51% lower probability of confirmed disability improvement (95% CI, 0.32 to 0.73). There was no difference in disability accumulation.

CONCLUSION

After fingolimod cessation, ocrelizumab and natalizumab were more effective in reducing relapses than cladribine. Due to the low ARRs in all three treatment groups, additional observation time is required to determine if statistical difference in ARRs results in long-term disability differences.

Position of Cladribine Tablets in the Management of Relapsing-Remitting Multiple Sclerosis: An Expert Narrative Review From the United Arab Emirates

The use of immune reconstitution therapies (IRT) in patients with relapsing-remitting multiple sclerosis (RRMS) is associated with a prolonged period of freedom from relapses in the absence of continuously applied therapy. Cladribine tablets is a disease-modifying treatment (DMT) indicated for highly active relapsing multiple sclerosis (MS) as defined by clinical or imaging features. Treatment with cladribine tablets is effective and well tolerated in patients with active MS disease and have a low burden of monitoring during and following treatment. In this article, an expert group of specialist neurologists involved in the care of patients with MS in the United Arab Emirates provides their consensus recommendations for the practical use of cladribine tablets according to the presenting phenotype of patients with RRMS. The IRT approach may be especially useful for patients with highly active MS insufficiently responsive to treatment with a first-line DMT, those who are likely to adhere poorly to a continuous therapeutic regimen, treatment-naïve patients with high disease activity at first presentation, or patients planning a family who are prepared to wait until at least 6 months after the end of treatment. Information available to date does not suggest an adverse interaction between cladribine tablets and COVID-19 infection. Data are unavailable at this time regarding the efficacy of COVID-19 vaccination in patients treated with cladribine tablets. Robust immunological responses to COVID-19 infection or to other vaccines have been observed in patients receiving this treatment, and treatment with cladribine tablets per se should not represent a barrier to this vaccination.

Altered expression of microRNAs and B lymphocytes during Natalizumab therapy in multiple sclerosis

MicroRNAs (miRNAs) are a family of non-translated small ribonucleic acids (RNAs) measuring 21–25 nucleotides in length that play various roles in multiple sclerosis (MS). By regulating gene expression via either mediating translational repression or cleavage of the target RNA, miRNAs can alter the expression of transcripts in different cells, such as B lymphocytes, also known as B cells. They are crucial in the pathogenesis of MS; however, they have not been extensively studied during the treatment of some drugs such as natalizumab (NTZ). NTZ is a humanized immunoglobulin G4 antibody antagonist for integrin alpha 4 (α4) used in the treatment of MS. The drug reduces the homing of lymphocytes to inflammation sites. Integrin α4 expression on the cell surface of B cells is related to MS severity, indicating a critical component in the pathogenesis of the disease. NTZ plays an important role in modifying the gene expression in B cells and the levels of miRNAs in the treatment of MS. In this review, we have described changes in gene expression in B cells and the levels of miRNAs during NTZ therapy in MS and its relapse. Studies using the experimental autoimmune encephalomyelitis (EAE) model and those involving patients with MS have described changes in the levels of microRNAs in the regulation of proteins affected by specific miRNAs, gene expression in B cells, and certain functions of B cells as well as their subpopulations. Therefore, there is a possibility that some miRNAs could be studied at different stages of MS during NTZ treatment, and these specific miRNAs can be tested as markers of therapeutic response to this drug in future studies. Physiopathology, gene expression in B cells and their subpopulations can help understand this complex puzzle involving miRNAs and the therapeutic response of patients with MS.

Efficacy of cladribine tablets in high disease activity patients with relapsing multiple sclerosis: post hoc analysis of subgroups with and without prior disease-modifying drug treatment

BACKGROUND

Relapsing-remitting multiple sclerosis (RRMS) patients with high disease activity (HDA) experience more severe disease than those without HDA. This analysis describes the efficacy of cladribine tablets 3.5 mg/kg in HDA patient subgroups that were either treated with disease-modifying drugs (DMDs) prior to study entry or were treatment naïve.

METHODS

Post hoc analysis of the 96 week Cladribine Tablets Treating Multiple Sclerosis Orally (CLARITY) study compared cladribine tablets 3.5 mg/kg to placebo in subgroups of patients meeting the high relapse activity plus disease activity on treatment definition of HDA. Patients were categorized into either prior DMD treatment or DMD treatment-naïve subgroups. Endpoints included annualized relapse rate (ARR), time to first relapse, time to disability progression and magnetic resonance imaging (MRI) outcomes. No inferential statistical analyses were conducted between subgroups.

RESULTS

The DMD-naïve cohort (n = 187) was larger than the prior-DMD cohort (n = 102). In both the DMD-naïve and prior-DMD cohorts, cladribine tablets were associated with a reduction in ARR (rate ratio [RR]: 0.26; 95% confidence interval [CI]: 0.16-0.42; p < .0001 and RR: 0.55; 95% CI: 0.32-0.95; p = .0324, respectively). In both subgroups, cladribine tablets increased the time to relapse versus placebo (hazard ratio [HR]: 0.36; 95% CI: 0.21-0.62; p = .0002 for DMD-naïve cohort and HR: 0.50; 95% CI: 0.24-1.02; p = .0557 for prior-DMD cohort). Significant differences were observed for all assessed disability and MRI outcomes independently of previous treatment.

CONCLUSION

Post hoc evidence suggests consistent treatment benefits of cladribine tablets 3.5 mg/kg during the 96 week CLARITY study among HDA-RRMS patients who were either previously treated with DMDs or were treatment naïve.

Family Planning for People with Multiple Sclerosis in Saudi Arabia: an Expert Consensus

More than half of all patients with multiple sclerosis (MS) in the Kingdom of Saudi Arabia (KSA) are women of childbearing age. Raising a family is an important life goal for women in our region of the world. However, fears and misconceptions about the clinical course of relapsing-remitting MS (RRMS) and the effects of disease-modifying drugs (DMDs) on the foetus have led many women to reduce their expectations of raising a family, sometimes even to the point of avoiding pregnancy altogether. The increase in the number of DMDs available to manage RRMS and recent studies on their effects in pregnancy have broadened management options for these women. Interferon beta now has an indication in Europe for use during pregnancy (according to clinical need) and can be used during breastfeeding. Glatiramer acetate is a further possible option for women with lower levels of RRMS disease activity who are, or about to become, pregnant; natalizumab may be used up to 30 weeks in patients with higher levels of disease activity. Where possible, physicians need to support and encourage women to pursue their dream of a fulfilling family life, supported where necessary by active interventions for RRMS that are increasingly evidence based.

Recent advances and remaining questions of autologous hematopoietic stem cell transplantation in multiple sclerosis

The judicious use of autologous hematopoietic stem cell transplantation (AHSCT) for MS requires understanding the potential benefits, identifying the most appropriate patient, and acknowledging the risks and differences between different protocols. Recently, AHSCT for MS is occurring more frequently, with a better safety profile than earlier studies. This review assesses recently published studies to determine the advances that have been made and remaining questions that future studies are poised to answer. We included studies from January 2016 to November 2020 with 20 or more patients. The benefits of AHSCT, including "no evidence of disease activity", functional and patient-reported outcomes, novel biomarkers such as brain atrophy or neurofilament light chain, and cost-effectiveness were assessed. The patient selection, treatment protocols, and safety outcomes differ between reports. The overall efficacy of AHSCT is better than standard treatments. Younger patients with highly active disease have greater chance for improvement, while patients who have comorbidities, failed more treatments, and are transitioning to a more progressive phase may not respond as well to AHSCT. The safety profiles for all AHSCT protocols is improving, however the durability of treatment response may not be the same for all protocols. The goal of AHSCT is to stop disease activity, avoid worsening disability, and obviate the need for further disease-modifying treatment, while improving patient quality of life and minimizing treatment-related risk. Results from currently enrolling randomized controlled trials, as well as ongoing registries, will provide more evidence for the safe and appropriate use of AHSCT.

Disease-Modifying Drugs and Family Planning in People with Multiple Sclerosis: A Consensus Narrative Review from the Gulf Region

Most disease-modifying drugs (DMDs) are contraindicated in pregnancy. Management of MS is especially challenging for pregnant patients, as withdrawal of DMDs leave the patient at risk of increased disease activity. We, a group of experts in MS care from countries in the Arab Gulf, present our consensus recommendations on the management of MS in these patients. Where possible, a patient planning pregnancy can be switched to a DMD considered safe in this setting. Interferon β now can be used during pregnancy, where there is a clinical need to maintain treatment, in addition to glatiramer acetate. Natalizumab (usually to 30 weeks' gestation for patients with high disease activity at high risk of relapse and disability progression) may also be continued into pregnancy. Cladribine tablets and alemtuzumab have been hypothesised to act as immune reconstitution therapies (IRTs). These drugs provide a period of prolonged freedom from relapses for many patients, but the patient must be prepared to wait for up to 20 months from initiation of therapy before becoming pregnant. If a patient becomes pregnant while taking fingolimod, and requires continued DMD treatment, a switch to interferon β or natalizumab after a variable washout period may be prescribed, depending on the level of disease activity. Women who wish to breastfeed should be encouraged to do so, and interferon β may also be used during breastfeeding. There is a lack of data regarding the safety of using other DMDs during breastfeeding.

The use of alemtuzumab in patients with relapsing-remitting multiple sclerosis: the Gulf perspective

Over the past decade, the development of high-efficacy disease-modifying therapies (DMTs) has been responsible for more effective management of relapsing-remitting multiple sclerosis (RRMS). However, the gaps in optimal care for this complex disease remain. Alemtuzumab (Lemtrada®) is a highly efficacious DMT that shows better patient outcomes and therapeutic benefits, but its use is under-recognized in the Gulf region. Experts in the care of multiple sclerosis shared their opinions based on study data and daily clinical experience in identifying the appropriate patient profile suitable for alemtuzumab's therapeutic benefits. Age, disease activity and severity, disability status, physician experience, and economic condition are some of the key indicators for alemtuzumab use.

Cladribine Tablets and Relapsing-Remitting Multiple Sclerosis: A Pragmatic, Narrative Review of What Physicians Need to Know

Immune reconstitution therapy (IRT) is an emerging management concept for multiple sclerosis, whereby a short course of treatment provides long-lasting suppression of disease activity. "Cladribine tablets 10 mg" refers to a total cumulative dose of cladribine given over 2 years (henceforth referred to as cladribine tablets 3.5 mg/kg); it is a relatively new treatment option that is hypothesised to act as an IRT acting preferentially on the adaptive immune system. A randomised, 2-year, placebo-controlled trial (CLARITY) showed that treatment with cladribine tablets reduced indices of disease activity (relapses, lesions on magnetic resonance images, disability progression) and that this effect outlasted the pharmacologic effect of the treatment on the immune system (mainly a reduction in circulating B and T cells, with little effect on components of the innate immune system such as monocytes). CLARITY Extension, a 2-year extension to this trial, demonstrated durable efficacy, also in patients who received the standard 2-year course of cladribine tablets 3.5 mg/kg and were re-randomised to placebo for a further 2 years. Relative risk reductions for relapse rate with cladribine tablets 3.5 mg/kg were similar for patients with or without prior high disease activity. Reductions in disability progression with cladribine tablets 3.5 mg/kg were higher in patients with prior high relapse rates with or without prior treatment non-response. In this review, we describe the therapeutic profile of cladribine tablets 3.5 mg/kg and provide practical information on initiating this treatment option in the most appropriate patients.

Expert consensus from the Arabian Gulf on selecting disease-modifying treatment for people with multiple sclerosis according to disease activity

Recent research has expanded our understanding of the natural history and clinical course of multiple sclerosis (MS) in the Arabian Gulf region. In addition, the number of available therapies for MS has increased greatly in recent years, which complicates considerably the design of therapeutic regimens. We, an expert group of physicians practising in Arabian Gulf countries, present pragmatic consensus recommendations for the use of disease-modifying therapy, according to the level of MS disease activity, according to objective criteria, and prior treatment (if any) received by a given patient.

Gene Therapy Approaches in an Autoimmune Demyelinating Disease: Multiple Sclerosis

Multiple Sclerosis (MS) is the most common autoimmune demyelinating disease of the Central Nervous System (CNS). It is a multifactorial disease which develops in an immune-mediated way under the influences of both genetic and environmental factors. Demyelination is observed in the brain and spinal cord leading to neuro-axonal damage in patients with MS. Due to the infiltration of different immune cells such as T-cells, B-cells, monocytes and macrophages, focal lesions are observed in MS. Currently available medications treating MS are mainly based on two strategies; i) to ease specific symptoms or ii) to reduce disease progression. However, these medications tend to induce different adverse effects with limited therapeutic efficacy due to the protective function of the blood-brain barrier. Therefore, researchers have been working for the last four decades to discover better solutions by introducing gene therapy approaches in treating MS generally by following three strategies, i) prevention of specific symptoms, ii) halt or reverse disease progression and iii) heal CNS damage by promoting remyelination and axonal repair. In last two decades, there have been some remarkable successes of gene therapy approaches on the experimental mice model of MS - experimental autoimmune encephalomyelitis (EAE) which suggests that it is not far that the gene therapy approaches would start in human subjects ensuring the highest levels of safety and efficacy. In this review, we summarised the gene therapy approaches attempted in different animal models towards treating MS.