Safety and efficacy of cladribine tablets in patients with relapsing-remitting multiple sclerosis: Results from the randomized extension trial of the CLARITY study

Treatment With Cladribine Selects IFNγ+IL17+ T Cells in RRMS Patients - An In Vitro Study

Background

Multiple sclerosis (MS) is an incurable autoimmune disease mediated by a heterogeneous T cell population (CD3+CD161+CXCR3−CCR6+IFNγ−IL17+, CD3+CXCR3+CCR6+IFNγ+IL17+, and CD3+CXCR3+IFNγ+IL17− phenotypes) that infiltrates the central nervous system, eliciting local inflammation, demyelination and neurodegeneration. Cladribine is a lymphocyte-depleting deoxyadenosine analogue recently introduced for MS therapy as a Disease Modifying Drug (DMD). Our aim was to establish a method for the early identification and prediction of cladribine responsiveness among MS patients.

Methods

An experimental model was designed to study the cytotoxic and immunomodulatory effect of cladribine. T cell subsets of naïve relapsing-remitting MS (RRMS) patients were analyzed ex vivo and in vitro comparatively to healthy controls (HC). Surviving cells were stimulated with rh-interleukin-2 for up to 14days. Cell proliferation and immunophenotype changes were analyzed after maximal (phorbol myristate acetate/ionomycin/monensin) and physiological T-cell receptor (CD3/CD28) activation, using multiparametric flow cytometry and xMAP technology.

Results

Ex vivo CD161+Th17 cells were increased in RRMS patients. Ex vivo to in vitro phenotype shifts included: decreased CD3+CCR6+ and CD3+CD161+ in all subjects and increased CD3+CXCR3+ in RRMS patients only; Th17.1 showed increased proliferation vs Th17 in all subjects; CD3+IL17+ and CD3+IFNγ+IL17+ continued to proliferate till day 14, CD3+IFNγ+ only till day 7. Regarding cladribine exposure: RRMS CD3+ cells were more resistant compared to HC; treated CD3+ cells proliferated continuously for up to 14 days, while untreated cells only up to 7 days; both HC/RRMS CD3+CXCR3+ populations increased from baseline till day 14; in RRMS patients vs HC, IL17 secretion from cladribine-treated cells increased significantly, in line with the observed proliferation of CD3+IL17+ and CD3+IFNγ+IL17+ cells; in both HC/RRMS, cladribine led to a significant increase in CD3+IFNγ+ cells at day 7 only, having no further effect at day14. IFNγ and IL17 secreted in culture media decreased significantly from ex vivo to in vitro.

Conclusions

CD3+ subtypes showed different responsiveness due to selectivity of cladribine action, in most patients leading to in vitro survival/proliferation of lymphocyte subsets known as pathogenic in MS. This in vitro experimental model is a promising tool for the prediction of individual responsiveness of MS patients to cladribine and other DMDs.

Immunomodulatory Effects Associated with Cladribine Treatment

Cladribine is a synthetic deoxyadenosine analogue with demonstrated efficacy in patients with relapsing-remitting multiple sclerosis (MS). The main mechanism of action described for cladribine is the induction of a cytotoxic effect on lymphocytes, leading to a long-term depletion of peripheral T and B cells. Besides lymphocyte toxicity, the mode of action may include immunomodulatory mechanisms affecting other cells of the immune system. In order to induce its beneficial effects, cladribine is phosphorylated inside the cell by deoxycytidine kinase (DCK) to its active form. However, the mechanism of action of cladribine may also include immunomodulatory pathways independent of DCK activation. This in vitro study was designed to explore the impact of cladribine on peripheral blood mononuclear cells (PBMC) subsets, and to assess whether the immunomodulatory mechanisms induced by cladribine depend on the activation of the molecule. To this end, we obtained PBMCs from healthy donors and MS patients and performed proliferation, apoptosis and activation assays with clinically relevant concentrations of cladribine in DCK-dependent and -independent conditions. We also evaluated the effect of cladribine on myeloid lineage-derived cells, monocytes and dendritic cells (DCs). Cladribine decreased proliferation and increased apoptosis of lymphocyte subsets after prodrug activation via DCK. In contrast, cladribine induced a decrease in immune cell activation through both DCK-dependent and -independent pathways (not requiring prodrug activation). Regarding monocytes and DCs, cladribine induced cytotoxicity and impaired the activation of classical monocytes, but had no effect on DC maturation. Taken together, these data indicate that cladribine, in addition to its cytotoxic function, can mediate immunomodulation in different immune cell populations, by regulating their proliferation, maturation and activation.

Expert opinion on COVID-19 vaccination and the use of cladribine tablets in clinical practice

BACKGROUND

Gaps in current evidence and guidance leave clinicians with unanswered questions on the use of cladribine tablets for the treatment of multiple sclerosis (MS) in the era of the COVID-19 pandemic, in particular relating to COVID-19 vaccination.

OBJECTIVE

We describe a consensus-based program led by international MS experts with the aim of supplementing current guidelines and treatment labels by providing timely recommendations relating to COVID-19 vaccination and the use of cladribine tablets in clinical practice.

METHODS

A steering committee (SC) of 10 international MS experts identified 7 clinical questions to answer concerning the use of cladribine tablets and COVID-19 vaccination, which addressed issues relating to patient selection, timing and efficacy, and safety. Clinical recommendations to address each question were drafted using available evidence combined with expert opinion from the SC. An extended faculty of 28 MS experts, representing 19 countries, in addition to the 10 SC members, voted on the recommendations. Consensus on recommendations was achieved when ⩾75% of respondents expressed an agreement score of 7-9, on a 9-point scale.

RESULTS

Consensus was achieved on all 13 recommendations. Clinical recommendations are provided on whether all patients with MS receiving cladribine tablets should be vaccinated against COVID-19, and whether they should be prioritized; the timing of vaccination around dosing of cladribine tablets (i.e. before and after a treatment course); and the safety of COVID-19 vaccination for these patients.

CONCLUSION

These expert recommendations provide timely guidance on COVID-19 vaccination in patients receiving cladribine tablets, which is relevant to everyday clinical practice.

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.

A Model-Based Economic Evaluation of Cladribine Versus Alemtuzumab, Ocrelizumab and Natalizumab for the Treatment of Relapsing-Remitting Multiple Sclerosis with High Disease Activity in Chile

PURPOSE

The aim of this study was to evaluate the cost effectiveness of cladribine compared with alemtuzumab, natalizumab, and ocrelizumab for the treatment of highly active multiple sclerosis (HAD-MS) from the perspective of the Chilean health care public sector.

MATERIALS AND METHODS

A Markov model was used to compare costs and quality-adjusted life-years (QALYs) over a 45-year time horizon using a 3% discount rate for costs and outcomes. Natural history of the disease was modeled in terms of progression of disability according to the Expanded Disability Status Scale (EDSS). A network meta-analysis was used as a source of comparative effectiveness for disability progression and annual relapse rates. Differences in costs and outcomes were modeled for only 10 years due to high temporal uncertainty. Ocrelizumab was assumed to have the same efficacy as cladribine due to lack of data. Direct costs were taken from national tariffs and expressed in 2019 US dollars. Utilities for EDSS health states were obtained from the literature. Second-order uncertainty was characterized through deterministic and probabilistic sensitivity analysis.

FINDINGS

Compared with natalizumab (the current strategy covered in Chile), cladribine is associated with incremental costs and QALYs of US$70,989 and 1.875, respectively (incremental cost-effectiveness ratio [ICER] $37,861). Ocrelizumab was extendedly dominated by cladribine and natalizumab, and alemtuzumab was dominated by cladribine. A scenario analysis of a 10% discount did not modify the results substantially, but showed a decrease in the ICER of cladribine versus natalizumab (ICER $29,833/QALY).

IMPLICATIONS

Cladribine is a new oral alternative to treat patients with HAD-MS that is expected to produce higher QALYs than all evaluated alternatives. In the context of a conservative analysis, cladribine cannot be considered cost effective for the Chilean health care public sector using a 1 GDP per capita threshold. However, under reasonable discount scenarios, cladribine becomes an attractive alternative for the health system.

Secondary Immunodeficiency and Risk of Infection Following Immune Therapies in Neurology

Secondary immunodeficiencies (SIDs) are acquired conditions that may occur as sequelae of immune therapy. In recent years a number of disease-modifying therapies (DMTs) has been approved for multiple sclerosis and related disorders such as neuromyelitis optica spectrum disorders, some of which are frequently also used in- or off-label to treat conditions such as chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis, myositis, and encephalitis. In this review, we focus on currently available immune therapeutics in neurology to explore their specific modes of action that might contribute to SID, with particular emphasis on their potential to induce secondary antibody deficiency. Considering evidence from clinical trials as well as long-term observational studies related to the patients' immune status and risks of severe infections, we delineate long-term anti-CD20 therapy, with the greatest data availability for rituximab, as a major risk factor for the development of SID, particularly through secondary antibody deficiency. Alemtuzumab and cladribine have relevant effects on circulating B-cell counts; however, evidence for SID mediated by antibody deficiency appears limited and urgently warrants further systematic evaluation. To date, there has been no evidence suggesting that treatment with fingolimod, dimethyl fumarate, or natalizumab leads to antibody deficiency. Risk factors predisposing to development of SID include duration of therapy, increasing age, and pre-existing low immunoglobulin (Ig) levels. Prevention strategies of SID comprise awareness of risk factors, individualized treatment protocols, and vaccination concepts. Immune supplementation employing Ig replacement therapy might reduce morbidity and mortality associated with SIDs in neurological conditions. In light of the broad range of existing and emerging therapies, the potential for SID warrants urgent consideration among neurologists and other healthcare professionals.

Pre-Existing Humoral Immunological Memory Is Retained in Patients with Multiple Sclerosis Receiving Cladribine Therapy

Cladribine (CLAD) is a lymphodepleting agent approved for active relapsing multiple sclerosis (MS). The impact of CLAD on the adaptive humoral immune system has not sufficiently been studied. This study aimed to assess the influence of CLAD treatment on specific antibody titers to common pathogens. We included 18 MS patients treated with CLAD. Serum IgG antibody levels to measles, mumps, rubella, hepatitis B and varicella zoster virus (VZV), as well as diphtheria and tetanus toxins, were measured prior to the initiation of treatment and at 12 and 24 months after first CLAD administration. Moreover, specimens were longitudinally analyzed regarding absolute blood concentrations of IgG and main lymphocyte subsets. No reduction in antibody levels against measles, mumps, rubella, VZV, hepatitis B, diphtheria toxin and tetanus toxin associated with CLAD treatment was observed. Loss of seroprotection occurred in <1%. We found no significant impact of CLAD on absolute serum IgG levels. Absolute lymphocyte counts were significantly reduced at the end of each treatment year (p < 0.00001 and p < 0.000001). This study suggests that CLAD does not interfere with the pre-existing humoral immunologic memory in terms of pathogen-specific antibody titers.

Efficacy of Cladribine Tablets as a Treatment for People With Multiple Sclerosis: Protocol for the CLOBAS Study (Cladribine, a Multicenter, Long-term Efficacy and Biomarker Australian Study)

Background

Cladribine tablets (marketed as Mavenclad) are a new oral therapy, which has recently been listed on the pharmaceutical benefits scheme in Australia for the treatment of relapsing multiple sclerosis (MS). The current dosing schedule is for 2 courses given a year apart, which has been shown to be effective for treatment of MS for up to 4 years in 75% of patients (based on annualized relapse rate). However, the reinitiation of therapy after year 4 has not been studied.

Objective

This study aims to evaluate the safety and efficacy of cladribine tablets over a 6-year period, according to no evidence of disease activity 3.

Methods

This will be a multicenter, 6-year, phase IV, low interventional, observational study that incorporates clinical, hematological, biochemical, epigenetic, radiological and cognitive biomarkers of disease. Participants considered for treatment with cladribine as part of their routine clinical care will be consented to take part in the study. They will be monitored at regular intervals during the initial course of medication administration in years 1 and 2. After year 3, patients will have the option of redosing, if clinically indicated, or to switch to another disease-modifying therapy. Throughout the duration of the study, we will assess blood-based biomarkers including lymphocyte subsets, serum neurofilament light chain, DNA methylation, and RNA analysis as well as magnetic resonance imaging findings (brain volume and/or lesion load) and cognitive performance.

Results

This study has been approved by the Hunter New England Local Health District Human Research Ethics Committee. Recruitment began in March of 2019 and was completed by June 2021.

Conclusions

This will be the first long-term efficacy trial of cladribine, which offers reinitiation of therapy in the 3rd year, based on disease activity, after the initial 2 courses. We expect that this study will indicate whether any of the assessed biomarkers can be used to predict treatment efficacy or the need for future reinitiation of cladribine in people with MS.

Trial Registration

This study is registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619000257167) with Universal Trial Number (U1111-1228-2165).

International Registered Report Identifier (IRRID)

DERR1-10.2196/24969

Durability of no evidence of disease activity-3 (NEDA-3) in patients receiving cladribine tablets: The CLARITY extension study

Background:

No evidence of disease activity (NEDA-3) is a patient-centric outcome increasingly used as the goal of multiple sclerosis treatment.

Objective:

Determine treatment durability of cladribine tablets beyond 2 years considering the variable bridging interval of 0.1–116.0 weeks between CLARITY and CLARITY Extension.

Methods:

Between CLARITY and CLARITY Extension, patients transitioned from cladribine tablets 3.5 mg/kg to placebo (CP3.5 group, n = 98) or continued further treatment with cladribine tablets 3.5 mg/kg (CC7.0 group, n = 186). Treatment assignment was randomized and blinded in both CLARITY and CLARITY Extension.

Results:

The 2-year NEDA-3 in CLARITY Extension (encompassing both years of CLARITY Extension) was 29.6% in the CP3.5 group and 32.8% in the CC7.0 group. There was no evidence that treatment effect differed with varying bridging intervals. For patients in the CP3.5 group with a bridging interval of ⩽48 weeks, 1 year NEDA-3 (the first year of CLARITY Extension) was 44.4% (28/63) compared with 31.4% (11/35) in patients with a bridging interval of >48 weeks.

Conclusion:

Treatment with cladribine tablets in CLARITY, followed by either placebo or cladribine tablets in CLARITY Extension, produced sustained benefits for NEDA-3 and its constituent elements for a follow up period up to 6 years from CLARITY baseline.

Headache in multiple sclerosis - pharmacological aspects

For decades, headache was not considered a typical symptom of multiple sclerosis (MS) and was construed as a "red flag" for important differential diagnoses such as cerebral vasculitis. Meanwhile, several studies have demonstrated an increased prevalence of headache in MS compared to the general population. This is due to the heterogeneity of headache genesis with frequent occurrence of both primary and secondary headaches in MS. On the one hand, MS and migraine are often comorbid. On the other hand, secondary headaches occur frequently, especially in the course of MS relapses. These are often migraine-like headaches caused by inflammation, which can improve as a result of MS-specific therapy. Headaches are particularly common in the early stages of chronic inflammatory CNS disease, where inflammatory activity is greatest. In addition, headache can also occur as a side effect of disease-modifying drugs (DMDs). Headache can occur with most DMDs and is most frequently described with interferon-beta therapy. The aim of this work is to present the prevalence of headache and describe the heterogeneity of possible causes of headache in MS. In addition, important therapeutic aspects in the treatment of MS patients in general will be presented as well as different approaches to the treatment of headache in MS depending on the etiological classification.

Treatment options in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

There are few diseases with as many therapeutic advances in recent years as in multiple sclerosis. Nine different drug classes with more than a dozen approved therapies are now available. Similarly, there have been unimaginable advances in understanding neuromyelitis optica (now neuromyelitis optica spectrum disorder [NMOSD]) over the past 15 years. Building on the knowledge gained, the first therapies have been approved in recent years. In this review, we aim to present all therapies approved for the treatment of MS or NMOSD. The different forms of application, different approval criteria and most important side effects will be presented. This work is intended for physicians who are interested in MS and NMOSD therapies and want to get a first overview and does not replace the respective guidelines of the regulatory authorities.

[Pharmacoeconomic aspects of using cladribine (in tablets) for treatment of adult patients with remitting multiple sclerosis]

OBJECTIVE

To conduct a pharmacoeconomic analysis of using cladribine (in tablets) as a second-line treatment option for adult patients with highly active remitting multiple sclerosis in Russia.

MATERIAL AND METHODS

Current treatment practice of highly active multiple sclerosis (natalizumab, fingolimod, alemtuzumab, ocrelizumab) was considered as a comparator for cladribine (in tablets). Clinical and economic study was conducted using the «cost minimization» method. For budget impact analysis cost of using cladribine (in tablets) was compared to the cost of using current treatment practice.

RESULTS

Cladribine in tablets is a cost-saving alternative for treatment of patients with highly active multiple sclerosis compared to the current treatment practice. Within a 4-year period direct medical costs reduction is 2 million RUB (50.1%) per person.

CONCLUSION

In case of switching the patients, who are currently provided with other disease modifying drugs, to cladribine, in 4 years health budget will save up to 6284 million RUB (50.1%).

Long-Term Disease Stability Assessed by the Expanded Disability Status Scale in Patients Treated with Cladribine Tablets 3.5 mg/kg for Relapsing Multiple Sclerosis: An Exploratory Post Hoc Analysis of the CLARITY and CLARITY Extension Studies

INTRODUCTION

In the Cladribine Tablets Treating Multiple Sclerosis Orally (CLARITY) study, cladribine tablets significantly reduced relapse rates and improved findings on magnetic resonance imaging versus placebo in patients with relapsing multiple sclerosis. In the CLARITY Extension study, treatment with cladribine tablets for 2 years followed by placebo for 2 years produced similar clinical benefits to 4 years of cladribine tablets. The objective of this exploratory post hoc analysis was to evaluate long-term disease stability (assessed by the Expanded Disability Status Scale [EDSS] score) after treatment with cladribine tablets.

METHODS

Patients enrolled into CLARITY Extension who were previously randomized to cladribine tablets 3.5 mg/kg in the CLARITY study were included in this post hoc analysis. Two treatment groups were investigated-patients randomized to cladribine tablets 3.5 mg/kg in CLARITY and thereafter randomized to placebo in CLARITY Extension (the CP3.5 group) or to cladribine tablets 3.5 mg/kg in CLARITY Extension (the CC7 group). In each treatment group, EDSS scores at 6-month intervals, EDSS score improvement/worsening each year, and time to 3- and 6-month confirmed EDSS progression were assessed from CLARITY baseline over 5 years of follow-up (including a variable bridging interval between studies). All analyses are descriptive, and no statistical comparisons were performed for between-treatment group differences.

RESULTS

The median (95% confidence interval [CI]) EDSS score for patients in the CP3.5 group at 5 years was 2.5 (2.0-3.5) compared with 3.0 (2.5-3.5) at baseline. In the CC7 group, median EDSS score (95% CI) at 5 years was 2.0 (2.0-3.0) compared with 2.5 (2.5-3.0) at baseline. During year 5 for the CP3.5 group, and based on changes in minimum score each year, EDSS score stability was observed in 53.9% of patients, improvement in 21.3%, and worsening in 24.7%. In the CC7 group, EDSS score remained stable in 66.1%, improved in 18.1%, and worsened in 15.8% of patients. Over 70% of patients in both treatment groups did not show 3- or 6-month confirmed EDSS progression at 5 years from CLARITY baseline.

CONCLUSIONS

These findings confirm long-term beneficial effects on disability afforded by either the recommended dose of cladribine tablets over 4 years (cumulative dose, 3.5 mg/kg) or a higher cumulative dose.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00213135 (CLARITY); NCT00641537 (CLARITY Extension).

Approach to optic neuritis: An update

Over the past few years, there has been remarkable development in the area of optic neuritis. The discovery of new antibodies has improved our understanding of the pathology of the disease. Antiaquaporin4 antibodies and antimyelin oligodendrocytes antibodies are now considered as distinct entities of optic neuritis with their specific clinical presentation, neuroimaging characteristics, treatment options, and course of the disease. Similarly, there has been a substantial change in the treatment of optic neuritis which was earlier limited to steroids and interferons. The development of new immunosuppressant drugs and monoclonal antibodies has reduced the relapses and improved the prognosis of optic neuritis as well as an associated systemic disease. This review article tends to provide an update on the approach and management of optic neuritis.

The Development of Cladribine Tablets for the Treatment of Multiple Sclerosis: A Comprehensive Review

Cladribine is a purine nucleoside analog initially developed in the 1970s as a treatment for various blood cancers. Due to the molecule’s ability to preferentially reduce T and B lymphocytes, it has been developed into an oral formulation for the treatment of multiple sclerosis (MS). The unique proposed mechanism of action of cladribine allows for the therapy to be delivered orally over two treatment-week cycles per year, one cycle at the beginning of the first month and one cycle at the beginning of the second month of years 1 and 2, with the potential for no further cladribine treatment required in years 3 and 4. This review summarizes the clinical development program for cladribine tablets in patients with MS, including the efficacy endpoints and results from the 2-year phase III CLARITY study in patients with relapsing–remitting MS (RRMS), the 2-year CLARITY EXTENSION study, and the phase III ORACLE-MS study in patients with a first clinical demyelinating event at risk for developing MS. Efficacy results from the phase II ONWARD study, in which cladribine tablets were administered as an add-on to interferon-β therapy in patients with RRMS, are also summarized. A review of all safety data, including lymphopenia, infections, and malignancies, is provided based on data from all trials in patients with MS, including the initial parenteral formulation studies. Based on these data, cladribine tablets administered at 3.5 mg/kg over 2 years have been approved across the globe for various forms of relapsing MS.

Economic Evaluation of Cladribine Tablets in Patients With High Disease Activity-Relapsing-Remitting Multiple Sclerosis in the Kingdom of Saudi Arabia

OBJECTIVE

Cladribine tablets are the first short-course oral treatment approved for high disease activity relapsing-remitting multiple sclerosis (HDA-RRMS) across various countries. This analysis assessed the cost-effectiveness of introducing cladribine tablets as a treatment option for patients with high disease activity compared with other HDA-RRMS therapies in the Kingdom of Saudi Arabia (KSA).

METHODS

The cost-effectiveness model was adapted from the KSA payer's perspective. Data for the model's adaptation were retrieved from the literature and validated by key opinion leaders. The comparators considered in the model were alemtuzumab, dimethyl fumarate, fingolimod, interferon beta-1a (subcutaneous and intramuscular) and beta-1b, natalizumab, and teriflunomide. A sensitivity analysis was also performed to assess the robustness of the analysis.

RESULTS

The cost-effectiveness results showed cladribine tablets as the dominant strategy (ie, less costly and more effective) versus all the comparators. The incremental cost and quality-adjusted life-years gained were largely driven by drug acquisition cost and delayed expanded disability status scale progression, respectively. Cladribine tablets showed an 81% to 100% probability of being cost-effective at a threshold of Saudi Riyal 225 326 per quality-adjusted life-years gained against different comparators.

CONCLUSIONS

Cladribine tablets are a dominant treatment option for patients with HDA-RRMS from the payer perspective in the KSA.

Treatment-emergent adverse events occurring early in the treatment course of cladribine tablets in two phase 3 trials in multiple sclerosis

Background

Treatment-emergent adverse events (TEAEs) that occur close to treatment initiation may negatively affect overall tolerability and adherence. It is important to develop a clear understanding of potential early TEAEs after initiating treatment with cladribine tablets.

Objective

To identify TEAEs that begin early in the course of treatment in patients enrolled in CLARITY and ORACLE-MS studies.

Methods

This post hoc analysis of CLARITY and ORACLE-MS safety populations assessed the incidence of TEAEs, serious TEAEs, drug-related TEAEs, and TEAEs leading to discontinuation in patients receiving cladribine tablets or placebo within 2, 6, and 12 weeks after treatment initiation.

Results

By Week 12, 61.3% of patients treated with cladribine tablets 3.5 mg/kg and 55.2% treated with placebo experienced a TEAE. More patients receiving cladribine tablets versus placebo experienced a drug-related TEAE by Week 12 (34.7% vs. 23.2%). The most common TEAEs reported with cladribine tablets were: headache (7.2%), lymphopenia (6.8%), and nausea (6.0%). Patients receiving cladribine tablets and placebo reported similar proportions of serious TEAEs (2.2% vs. 1.7%) and TEAEs leading to treatment discontinuation (1.6% vs. 1.4%).

Conclusion

Cladribine tablets were well tolerated during the first 12 weeks as evidenced by a low incidence of TEAEs leading to treatment discontinuation.

Pregnancy Outcomes During the Clinical Development Program of Cladribine in Multiple Sclerosis: An Integrated Analysis of Safety

Introduction

Although use of contraception was pre-specified during cladribine clinical trials for multiple sclerosis, some pregnancies did occur.

Objective

This analysis reports on pregnancy outcomes in the cladribine clinical development program.

Methods

Pregnancy outcomes in female patients (direct pregnancies) and those arising from partner pregnancies (i.e., female partners of male study participants with multiple sclerosis) were evaluated from an integrated safety analysis of ten studies of cladribine in multiple sclerosis (nine clinical trials and a long-term safety registry), with patients treated with cladribine tablets, parenteral cladribine, or placebo (all-exposed cohort; 1976 patients received cladribine and 802 received placebo). Pregnancies that occurred during the ‘at-risk’ period for cladribine (during treatment or within 6 months thereafter) are reported as a separate group.

Results

In the all-exposed cohort, 70 direct pregnancies occurred among 62 female patients (cladribine, n = 49; placebo, n = 21). Pregnancy outcomes were: live births (cladribine, n = 19 [38.8%]; placebo, n = 9 [42.9%]), elective terminations (cladribine, n = 14 [28.6%]; placebo, n = 4 [19.0%]), spontaneous abortions (cladribine, n = 11 [22.4%]; placebo, n = 5 [23.8%]), and therapeutic terminations (cladribine, n = 5 [10.2%]; placebo, n = 2 [9.5%]); in the remaining placebo recipient, the pregnancy outcome was unknown. There were two reports of congenital malformations (cladribine, n = 1; placebo, n = 1), both of which occurred with pregnancies arising > 2 years after exposure to the last dose of study medication. Sixteen direct pregnancies occurred during the ‘at-risk’ period for cladribine; outcomes for these were: live births, n = 3 (18.8%); elective terminations, n = 10 (62.5%); spontaneous abortions, n = 2 (12.5%); and therapeutic terminations, n = 1 (6.2%). Corresponding findings for direct pregnancies among placebo recipients were (n = 11): live births, n = 5 (45.5%); elective terminations, n = 2 (18.2%); spontaneous abortions, n = 3 (27.3%); and unknown, n = 1 (9.1%). No cases of congenital malformation were reported for pregnancies during the ‘at-risk’ period. There were an additional nine partner pregnancies in female partners of cladribine-treated male patients, all of which resulted in live births; of these, two pregnancies occurred within the ‘at-risk’ period for cladribine.

Conclusions

While limited by the small number of pregnancies and related data from the cladribine clinical development program, highlighting the need for further study, the observations made in the present analysis were generally consistent with epidemiological data on pregnancy outcomes for the general population or women with multiple sclerosis. There were no congenital malformations in pregnancies that occurred during cladribine treatment or within 6 months after the last dose. As the data available for cladribine-exposed pregnancies in patients with multiple sclerosis are limited, a non-interventional post-authorization safety study has been initiated to obtain more information on this subject.

Clinical Trial Registration

CLARITY: NCT00213135; CLARITY Extension: NCT00641537; ORACLE MS: NCT00725985; ONWARD: NCT00436826; PREMIERE: NCT01013350.

The Disease-Modifying Therapies of Relapsing-Remitting Multiple Sclerosis and Liver Injury: A Narrative Review

In this narrative review, we analyze pre-registration and post-marketing data concerning hepatotoxicity of all disease-modifying therapies (DMTs) available for the treatment of relapsing-remitting multiple sclerosis, including beta interferon, glatiramer acetate, fingolimod, teriflunomide, dimethyl fumarate, cladribine, natalizumab, alemtuzumab, and ocrelizumab. We review the proposed causal mechanisms described in the literature and we also address issues like use of DMTs in patients with viral hepatitis or liver cirrhosis. Most data emerged in the post-marketing phase by reports to national pharmacovigilance agencies and published case reports or case series. Serious liver adverse events are rare, but exact incidence is largely unknown, as are predictive factors. Unfortunately, none of the DMTs currently available for the treatment of multiple sclerosis is free of potential hepatic toxic effects. Cases of acute liver failure have been reported for beta-interferon, fingolimod, natalizumab, alemtuzumab, and ocrelizumab by different mechanisms (idiosyncratic reaction, autoimmune hepatitis, or viral reactivation). Patients with multiple sclerosis should be informed about possible hepatic side effects of their treatment. Most cases of liver injury are idiosyncratic and unpredictable. The specific monitoring schedule for each DMT has been reviewed and the clinician should be ready to recognize clinical symptoms suggestive for liver injury. Not all DMTs are indicated in cirrhotic patients. For some DMTs, screening for hepatitis B virus and hepatitis C virus is required before starting treatment and a monitoring or antiviral prophylaxis schedule has been established. Beta interferon, glatiramer acetate, natalizumab, and alemtuzumab are relatively contraindicated in autoimmune hepatitis due to the risk of disease exacerbation.

Autoimmune glomerulonephritis in a multiple sclerosis patient after cladribine treatment

BACKGROUND

Oral cladribine is an approved disease-modifying drug for the treatment of relapsing multiple sclerosis. In controlled clinical trials as well as in post marketing safety assessments, autoimmune conditions have not yet been reported as a specific side effect of cladribine.

OBJECTIVE AND RESULTS

Here, we report a case of anti-glomerular basement membrane antibody-mediated glomerulonephritis that occurred shortly after the fourth cladribine treatment cycle.

CONCLUSION

Neurologists should be attentive to the development of secondary autoimmunity in cladribine-treated patients.

Oral pulsed therapy of relapsing multiple sclerosis with cladribine tablets - expert opinion on issues in clinical practice

BACKGROUND

Oral cladribine is the first oral pulsed therapy licensed for relapsing multiple sclerosis (RMS). Three years after the introduction into the European market, we evaluated practical aspects in the use of cladribine tablets, incorporating the experience gained in routine clinical practice and real-world studies.

METHODS

Based on a structured review process, a panel of nine neurologists experienced in MS therapy discussed salient statements regarding the use of cladribine tables. For each statement the level of evidence was determined according to the levels of evidence recommended by the Centre for Evidence-Based Medicine, Oxford. The strength of each expert statement was then evaluated by means of a linear scale from 1 (very strong rejection) to 9 (very strong approval). Votes were collected by a formalized blinded process. Consent was considered to be reached if at least 75% of the experts agreed on a particular statement (i.e. voted for 7-9 points on the linear scale).

RESULTS

. Statements include efficacy in early RMS, risk of side effects and infections, vaccination, pregnancy, and monitoring requirements.

CONCLUSION

The consented recommendations summarize the practical experience inthe use of cladribine tablets in a real-world setting. These may provide guidance for unanswered questions arising with the introduction of new treatments such as cladribine tablets.

Update on treatment in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. In recent years, many disease-modifying therapies (DMT) have been approved for MS treatment. For this reason, a profound knowledge of the characteristics and indications of the available compounds is required to tailor the therapeutic strategy to the individual patient characteristics. This should include the mechanism of action and pharmacokinetic of the drug, the safety and efficacy profile provided by clinical trials, as well as the understanding of possible side effects. Moreover, the evolving knowledge of the disease is paving the way to new and innovative therapeutic approaches, as well as the development of new biomarkers to monitor the therapeutic response and to guide the clinician's therapeutic choices. In this review we provide a comprehensive overview on currently approved therapies in MS and the emerging evidence-based strategies to adopt for initiating, monitoring, and eventually adapting a therapeutic regimen with DMT.

Effectiveness and safety of cladribine in MS: Real-world experience from two tertiary centres

Background:

Oral cladribine has been approved for the treatment of relapsing multiple sclerosis (MS) yet real-world evidence regarding its effectiveness and safety remains scarce.

Objective:

To evaluate efficacy and safety outcomes of MS patients following induction of cladribine.

Methods:

We evaluated our prospective cohort of cladribine-treated MS patients from two tertiary centres in Germany. Relapses, disability worsening and occurrence of new or enlarging T2-hyperintense magnetic resonance imaging (MRI) lesions were assessed as well as lymphocyte counts and herpes virus infections.

Results:

Among 270 patients treated with cladribine, we observed a profound reduction of both relapses and new or enlarging MRI lesions. Treatment appeared more efficacious, especially in patients without previous therapy or following platform substances. Patients switching from natalizumab were prone to re-emerging disease activity. Among patients following dimethyl fumarate pre-treatment, severe lymphopenia was common and associated with increased rates of herpes virus manifestations.

Conclusion:

Overall, we observed an efficacy and safety profile of cladribine consistent with data from the phase 3 clinical trial. However, patients switching from natalizumab experienced suboptimal disease control beyond rebound activity following cessation of natalizumab. Furthermore, dimethyl fumarate pre-treatment was associated with a profound risk of developing severe lymphopenia and subsequent herpes virus infections.

Analysis of frequency and severity of relapses in multiple sclerosis patients treated with cladribine tablets or placebo: The CLARITY and CLARITY Extension studies

Background:

In the CLARITY (CLAdRIbine Tablets treating multiple sclerosis orallY) study of patients with relapsing-remitting multiple sclerosis, treatment with cladribine tablets 3.5 mg/kg (CladT) significantly reduced the annualised relapse rate (ARR) versus placebo; this effect was sustained in CLARITY Extension, without further treatment.

Objective:

To assess the frequency and severity of relapses in patients treated with CladT versus placebo in CLARITY over 2 years and evaluate the durability of effect in patients who received no further treatment for 2 years in CLARITY Extension.

Methods:

In this post hoc analysis, ARRs were calculated for qualifying and all relapses, and qualifying and all severe relapses (i.e. requiring steroid treatment or leading to hospitalisation) in patients treated with CladT (n = 433) and placebo (n = 437) in CLARITY, and those from the CladT group who received placebo in CLARITY Extension (n = 98).

Results:

At Month 6, Year 1 and Year 2, patients receiving CladT had a significantly lower risk of qualifying or all relapses (all p < 0.0001), and qualifying or all severe relapses (all p < 0.005), compared with placebo. This effect was sustained in CLARITY Extension without further treatment.

Conclusion:

The results show durable efficacy of cladribine tablets 3.5 mg/kg for reducing frequency and severity of relapses in patients with relapsing-remitting multiple sclerosis.

CLARITY: NCT00213135; CLARITY Extension: NCT00641537

JC Virus Seroprevalence and JCVAb Index in Polish Multiple Sclerosis Patients Treated with Immunomodulating or Immunosuppressive Therapies

The use of a highly-effective treatment for multiple sclerosis (MS) is associated with a severe risk of developing complications, such as progressive multifocal leukoencephalopathy (PML) caused by the John Cunningham virus (JCV). The aim of this study was to evaluate the correlation between anti-JCV Ab seroprevalence, anti-JCV AI, demographic and clinical factors as well as the type of therapy used in the Polish MS population. This is a multicentre, prospective and cross-sectional study involving 1405 MS patients. The seroprevalence of anti-JCV Ab and anti-JCV AI levels as well as AI categories were analysed with the use of a second-generation two-step ELISA test (STRATIFY JCV DxSelect). The overall prevalence of anti-JCV Ab was 65.8%. It was shown that seroprevalence increases with the patient's age. The seroprevalence was significantly associated with the treatment type, and the highest values (76%) were obtained from immunosuppressant-treated patients. Overall, 63.3% of seropositive patients had an antibody index (AI) level of >1.5. In the seropositive patient group, the mean AI level amounted to 2.09. Similarly to the seroprevalence, AI levels correlated with the patient's age; AI level for patients above 40 years old and from subsequent age quintiles plateaued, amounting to at least 1.55. Patients treated with immunosuppressants and immunomodulatory drugs obtained the highest (1.67) and lowest (1.35) AI levels, respectively. Of the immunosuppressants used, the highest mean AI levels were observed in mitoxantrone and cladribine groups, amounting to 1.75 and 1.69, respectively. In patients treated with immunomodulatory drugs, the lowest AI levels were observed in the dimethyl fumarate (DMF) group (1.11). The seroprevalence rate in the Polish MS population is one of the highest in Europe. The majority of seropositive patients had an anti-JCV Ab level qualifying them for a high-risk category. The highest mean AI levels are observed in patients receiving immunosuppressants, especially mitoxantrone and cladribine. Patients receiving immunomodulatory drugs have lower AI levels compared to treatment-naïve subjects, especially when treated with DMF. Further studies, especially longitudinal studies, are required to determine the impact of MS drugs on the seroprevalence of anti-JCV Ab and AI levels.

The development and impact of cladribine on lymphoid and myeloid cells in multiple sclerosis

Cladribine is an approved selective immune reconstitution therapy for relapsing-remitting MS (RRMS). It was first developed and used to treat various forms of cancer, particularly leukemia via parenteral administration. The oral tablet version of cladribine was later developed to treat RRMS, an autoimmune disorder of the central nervous system (CNS) with periods of relapse and remission. Cladribine is found to selectively deplete adaptive immune cell types, and its role on innate immune cells is largely unknown. Among the lymphocyte populations and subtypes, the magnitude and kinetics of depletion by cladribine vary substantially. The current consensus on the selective cytotoxic effect of cladribine is that it is dependent on the deoxycytidine kinase (DCK) to 5'nucleotidase (5-NT) ratio of the immune cell type. Nonetheless, there are some discrepancies that cannot be fully elucidated by the DCK:5-NT ratio paradigm. This review aims to delineate the development and pharmacological properties of cladribine, and elucidate its influence on lymphoid and myeloid cells in MS.

A real-world single-centre analysis of alemtuzumab and cladribine for multiple sclerosis

BACKGROUND

Highly active MS may warrant higher efficacy treatments for disease control. However, these often confer more risk and have not been compared in head-to-head clinical trials, making relative efficacy and safety difficult to interpret. Alemtuzumab and cladribine are two high-efficacy treatments given as discrete courses separated by one year, followed by a durable response that potentially does not require ongoing treatment. Before the approval of oral cladribine, our centre had been treating patients with a bioequivalent intravenous (IV) regimen since 2010. The objective of this study is to report the safety and efficacy data of alemtuzumab and cladribine in a real-world, single centre setting.

METHODS

We retrospectively reviewed all patients treated with alemtuzumab or cladribine at the Ottawa Hospital MS Clinic with 2 or more years of follow-up. Information on baseline demographic variables, previous treatment, and prior disease activity was collected. Outcomes investigated were "no evidence of disease activity" (NEDA) and its constituents: new clinical relapse, new MRI activity, and Expanded Disability Status Scale (EDSS) progression; as well as any adverse events or treatment discontinuation. We performed univariate and multiple logistic regression to determine differences in 2-year NEDA and time-to-event analyses with Cox regression models to determine factors associated with each outcome through the study period.

RESULTS

Forty-six patients were treated with alemtuzumab and 65 with cladribine of whom 51 (78%) received the intravenous regimen, followed for a total of 420.1 person-years. The cladribine group was older (p=.0002), with higher baseline EDSS (p=.0015), and more likely secondary progressive (p<.0001). Alemtuzumab had a higher rate of 2-year NEDA than cladribine (OR 4.78, 95%CI: 1.57-14.50, p=.006), but beyond 2 years the difference was not statistically significant (HR 0.50, 95%CI: 0.25-1. 30, p=.061). More prior treatments were associated with lower likelihood of retaining NEDA (HR 1.26, 95%CI: 1.03-1.54, p=.027). Alemtuzumab had more infusion reactions (80% vs. 17%, p<.0001), shingles (22% vs. 2%, p=.005), and secondary autoimmunity (52% vs. 3%, p<.0001) than cladribine, but there was no difference in grade 3 or higher adverse events (21.7% vs. 18.5%, p=1.0).

CONCLUSION

In our cohort alemtuzumab and cladribine achieved similar rates of NEDA in long-term follow-up, with overall less adverse events with cladribine. Patient registries would allow more robust comparisons, detection of adverse events, and assessment of a durable response.

Skin Reactions in Patients With Multiple Sclerosis Receiving Cladribine Treatment

Objective

To report 77 patients with multiple sclerosis (MS) who developed skin-related adverse events (AEs) following treatment with cladribine.

Methods

We evaluated our prospective bicentric cladribine cohort. Cladribine-treated patients with a skin AE were identified.

Results

Two hundred thirty-nine cladribine-treated patients with MS were evaluated. Seventy-seven patients (32%) showed at least 1 skin AE at median 1 month after cladribine initiation (range: 1–12). Within first 3 months following last cladribine exposition, hair thinning (n = 28, 12%), skin rash (n = 20; 8%), mucositis (n = 13, 5%), and pruritus (n = 6, 3%) were observed. Furthermore, 35 patients (15%) developed herpes virus infections (time since last cladribine exposition: median 83 [range: 10–305]). In 15 patients, herpes zoster infection was severe (CTCAE grade ≥ 3) and required hospitalization. Delayed skin AEs (≥3 months after a cladribine treatment cycle) involved 1 case of leukocytoclastic vasculitis and 2 cases of alopecia areata. Finally, 2 patients presented with in total 3 isolated precancerous lesions (1 leukoplakia simplex and 2 actinic keratosis) and 1 patient developed a squamous cell carcinoma.

Conclusion

Skin AEs are common in patients with MS treated with cladribine. Until risk management plans have been adjusted to include these phenomena, clinicians should perform a thorough clinical follow-up and in suspicious cases seek early interdisciplinary support. In light of the observed delayed skin reactions, we further emphasize the necessity of careful clinical surveillance of cladribine-treated patients for yet undescribed secondary autoimmune events.

Classification of Evidence

This study provides Class IV evidence that skin-related AEs are frequent in patients with MS following cladribine in a real-world setting.

CLICK-MS and MASTER-2 Phase IV trial design: cladribine tablets in suboptimally controlled relapsing multiple sclerosis

Cladribine tablets 10 mg (3.5 mg/kg cumulative dose over 2 years) are approved for the treatment of relapsing forms of multiple sclerosis (MS), including relapsing-remitting MS and active secondary progressive MS. However, real-world data on cladribine tablets are limited. CLICK-MS and MASTER-2 are single arm, observational, 30-month, Phase IV studies in the US evaluating the effectiveness and safety of cladribine tablets 3.5 mg/kg in patients with relapsing-remitting MS or active secondary progressive MS who had suboptimal response to prior injectable (CLICK-MS), or infusion/oral (MASTER-2) disease-modifying therapy. The primary end point is 24-month annualized relapse rate. Key secondary end points include patient-reported outcomes on quality of life measures, treatment adherence and adverse events. Studies began in 2019 and are expected to be completed in 2023. Trial registration number • CLICK-MS: NCT03933215 (ClinicalTrials.gov) Full title; CLadribine tablets: observational evaluation of effectIveness and patient-reported outcomes in suboptimally Controlled patients previously taKing injectable disease-modifying drugs for relapsing forms of Multiple Sclerosis • MASTER-2: NCT03933202 (ClinicalTrials.gov) Full title; Cladribine tablets: observational evaluation of effectiveness and patient-reported outcomes in suboptiMAlly controlled patientS previously Taking oral or infusion disEase-modifying dRugs for relapsing forms of multiple sclerosis.

Exit Strategies in Natalizumab-Treated RRMS at High Risk of Progressive Multifocal Leukoencephalopathy: a Multicentre Comparison Study

The main aim of the study is to evaluate the efficacy and safety profile of ocrelizumab (OCR), rituximab (RTX), and cladribine (CLA), employed as natalizumab (NTZ) exit strategies in relapsing-remitting multiple sclerosis (RRMS) patients at high-risk for progressive multifocal leukoencephalopathy (PML). This is a multicentre, retrospective, real-world study on consecutive RRMS patients from eleven tertiary Italian MS centres, who switched from NTZ to OCR, RTX, and CLA from January 1st, 2019, to December 31st, 2019. The primary study outcomes were the annualized relapse rate (ARR) and magnetic resonance imaging (MRI) outcome. Treatment effects were estimated by the inverse probability treatment weighting (IPTW), based on propensity-score (PS) approach. Additional endpoint included confirmed disability progression (CDP) as measured by Expanded Disability Status Scale and adverse events (AEs). Patients satisfying predefined inclusion and exclusion criteria were 120; 64 switched to OCR, 36 to RTX, and 20 to CLA. Patients from the 3 groups did not show differences for baseline characteristics, also after post hoc analysis. The IPTW PS-adjusted models revealed that patients on OCR had a lower risk for ARR than patients on CLA (ExpBOCR 0.485, CI 95% 0.264-0.893, p = 0.020). This result was confirmed also for 12-month MRI activity (ExpBOCR 0.248 CI 95% 0.065-0.948, p = 0.042). No differences were found in other pairwise comparisons (OCR vs RTX and RTX vs CLA) for the investigated outcomes. AEs were similar among the 3 groups. Anti-CD20 drugs were revealed to be effective and safe options as NTZ exit strategies. All investigated DMTs showed a good safety profile.

Assessing and mitigating risk of infection in patients with multiple sclerosis on disease modifying treatment

Introduction: The important development that the multiple sclerosis (MS) treatment field has experienced in the last years comes along with the need of dealing with new adverse events such as the increase risk of infections. In the shared therapeutic decision-making process, the MS expert neurologist should also balance the risks of specific infections under each particular treatment and be familiar with new mitigation strategies.Areas covered: In this review, the authors provide an up-to-date review of the infection risk associated with MS treatments with a specific focus on risk mitigating strategies. The search was conducted using Pubmed® database (2000 - present) to identify publications that reported infection rates and infection complications for each treatment (interferon beta, glatiramer acetate, teriflunomide, dimethyl fumarate, fingolimod, cladribine, natalizumab, alemtuzumab, rituximab, and ocrelizumab).Expert opinion: Since the emergence of the first natalizumab-related PML case, the arrival of new MS therapies has come hand in hand with new infectious complications. MS-specialist neurologist has to face new challenges regarding the management of immunosuppression-related infectious complications. The implementation of patient-centered management focus on preventive and mitigating strategies with a multidisciplinary approach should be seen in the future as a marker of excellence of MS management.

Real-world effectiveness of cladribine for Australian patients with multiple sclerosis: An MSBase registry substudy

BACKGROUND/OBJECTIVE

Observational clinical data from cladribine-treated patients with relapsing forms of multiple sclerosis (MS) were recorded in the Australian MS registry powered by the MSBase registry platform (5-year follow-up) and analysed to complement information from the pivotal cladribine clinical trials in MS.

METHODS

A cohort of 90 cladribine-treated patients with follow-up data reported by treating physicians and recorded in the Australian MSBase registry (database lock February 2016) were examined. Clinical data included Expanded Disability Status Scale (EDSS) scores, relapses and other disease-modifying drugs (DMDs) administered before and after cladribine treatment.

RESULTS

Mean age on starting cladribine was 47 years; mean age at MS onset was 34 years, and median baseline EDSS score was 5.25. Disability trajectories in patients with sufficient follow-up suggested an overall increasing trend prior to cladribine treatment which was reduced during the 2-year post-treatment. Approximately 80% of patients were EDSS progression-free, 65% remained relapse-free after 2 years and median time to next DMD was 1.7 years.

CONCLUSION

These observational data suggest a disease-modifying effect in this cohort of relapsing MS patients characterised by older and more disabled patients. Since these data represent a single-arm cohort, clinical trials and larger comparative post-marketing studies are needed to validate and extend these findings.

Prevention and management of adverse effects of disease modifying treatments in multiple sclerosis

PURPOSE OF REVIEW

To summarize the currently known side effects of the approved therapies of multiple sclerosis and to suggest monitoring procedures.

RECENT FINDINGS

The progress in the treatment of multiple sclerosis with new very effective therapies is accompanied by a number of side effects. Some of these have already been described in the approval studies, but some only after approval in a real world situation. The reason for this is the short duration of the clinical studies, the very heterogeneous patient profile in the real world setting with a number of comorbidities, pretherapies, and wider age range. The side effects may occur during application of therapies or afterwards during the course of the treatment. The side effects may range from mild infections, mild laboratory abnormalities, secondary autoimmune diseases to life-threatening side effects such as progressive multifocal leukoencephalopathy.

SUMMARY

It has to be pointed out that these side effects are not to be considered as final and neurologists should be vigilant against new unknown side effects. The doctor should be aware of these undesirable effects, should weigh the benefits of the therapies against the risks, but at the same time she/he should keep in mind that multiple sclerosis can be a very disabling disease if not treated properly.

Multiple Sclerosis and SARS-CoV-2 Vaccination: Considerations for Immune-Depleting Therapies

Several concerns have been raised about the use of immunodepleting agents including alemtuzumab, cladribine and CD20-depleting antibodies in people with multiple sclerosis (pwMS) during the coronavirus disease (COVID) 2019 pandemic. As the end of the pandemic is not yet in sight, vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) may be an elegant strategy to overcome the potential hazards associated with initiating and continuing treatment with immune-depleting agents. In this review, we summarize the immunological effects of immune-depleting therapy and underlying considerations for the hitherto existing recommendations that suggest a restricted use of immune-deleting therapies during the pandemic. Moreover, we critically discuss open questions regarding vaccination in general and against SARS-CoV-2 in pwMS.

Cladribine tablets versus other disease-modifying oral drugs in achieving no evidence of disease activity (NEDA) in multiple sclerosis-A systematic review and network meta-analysis

INTRODUCTION

Assuming full control of the relapsing-remitting multiple sclerosis (RRMS) is the main target for practitioners. Disease control could be defined as no clinical relapse, absence of 3-month confirmed disability progression expressed on the Expanded Disability Status Scale (EDSS), as well as no disease activity on magnetic resonance imaging (MRI). NEDA-3 (no evidence of disease activity) is a composite endpoint used primarily in clinical trials, comprising these 3 measurements of disease activity. The aim of this study is to compare cladribine tablets (CT) with oral disease-modifying drugs (DMDs) - fingolimod (FTY), dimethyl fumarate (DMF), and teriflunomide (TERI) - with regard to NEDA-3 and its clinical (relapse and disability progression) and MRI (no new T1 Gd+ lesions or no new T2 lesions or no enlargement of existing lesions) components occurrence during a 24-month follow-up.

METHODS

In June 2018, a systematic review of MEDLINE, Embase and Cochrane database was performed. Due to the lack of head-to-head trials directly comparing cladribine tablets to oral drugs of interest, an indirect network meta-analysis (NMA) was applied, with placebo as a common comparator. NMA was performed with Bayesian approach and Markov chain Monte Carlo (MCMC) method for estimating posterior distributions. Additional data used in the analysis were taken from conference abstracts or post hoc analyses of pooled data from the clinical studies.

RESULTS

Six randomised clinical trials (RCTs) presenting NEDA, with active treatment compared to placebo, were included in the NMA: CLARITY (CT), FREEDOMS and FREEDOMS II (FTY), CONFIRM and DEFINE (DMF) and TEMSO (TERI). The rate of NEDA-3 was significantly higher in cladribine tablets vs DMF: OR (odds ratio)=1.76 (95% CrI [credible intervals]: 1.02-3.03) and TERI: OR=2.78 (95% CrI: 1.60-4.83), but not vs FTY. For the MRI NEDA results were as follows - cladribine tablets vs DMF: OR=1.87 (95% CrI: 1.18-2.97); cladribine tablets vs TERI: OR=6.59 (95% CrI: 4.32-10.09); cladribine tablets vs FTY: OR=1.58 (95% CrI: 1.10-2.29). The comparison of clinical NEDA did not reach significance vs either DMF or TERI and evaluation vs FTY was not possible because of lack of data.

CONCLUSIONS

Cladribine in the form of tablets was significantly more effective in achieving NEDA-3 than DMF and TERI, but there was no significant difference vs FTY. Cladribine tablets was more effective than all oral comparators considering the MRI NEDA. For clinical NEDA, the superiority vs DMF and vs TERI was not confirmed, and vs FTY evaluation was not possible.

Safety of Newer Disease Modifying Therapies in Multiple Sclerosis

In the past decade, the therapeutic arsenal for multiple sclerosis has expanded greatly. Newer more potent disease modifying therapies (DMTs) with varying mechanisms of actions are increasingly used early in the disease course. These newer DMTs include oral therapies (teriflunomide, dimethyl fumarate, fingolimod, siponimod, ozanimod, and cladribine) and infusion therapies (natalizumab, alemtuzumab, and ocrelizumab), and are associated with better control of disease activity and long-term outcomes in patients with MS compared to older injectable therapies (interferon beta and glatiramer acetate). However, they are associated with safety concerns and subsequent monitoring requirements. Adverse events are initially observed in phase 2 and 3 clinical trials, and further long-term data are collected in phase 3 extension studies, case series, and post-marketing reports, which highlight the need to periodically re-evaluate and adjust monitoring strategies to optimize treatment safety in an individualized approach.

Subgroup analysis of clinical and MRI outcomes in participants with a first clinical demyelinating event at risk of multiple sclerosis in the ORACLE-MS study

BACKGROUND

In the Phase 3, 96-week ORACLE-MS study, cladribine 10 mg tablets (3.5 mg/kg or 5.25 mg/kg cumulative dose over 2 years) significantly reduced the rate of conversion to clinically definite multiple sclerosis (CDMS) per the Poser criteria (henceforth referred to as CDMS), multiple sclerosis (MS) per the 2005 McDonald criteria, and the number of new or persisting T1 gadolinium-enhancing (Gd+), new or enlarging T2, and combined unique active (CUA) lesions versus placebo in participants with a first clinical demyelinating event (FCDE). Patient demographic and disease characteristics may be predictors of disease progression. The current study analyzed the effect of cladribine tablets in subgroups of participants in the ORACLE-MS study by baseline demographics and disease characteristics.

METHODS

This analysis retrospectively examined data collected from 616 participants enrolled in the ORACLE-MS study (placebo, n=206; cladribine tablets 3.5 mg/kg, n=206; cladribine tablets 5.25 mg/kg, n=204). Five subgroups were predetermined by baseline demographics, including sex, age (<30 or ≥30 years), classification of FCDE, and lesion characteristics, including absence or presence of T1 Gd+ lesions and number of T2 lesions (<9 or ≥9). Selected endpoints of the ORACLE-MS study were re-analyzed for these subgroups. The primary and main secondary endpoints were time to conversion to CDMS and MS (2005 McDonald criteria), respectively. Secondary magnetic resonance imaging (MRI) endpoints included cumulative T1 Gd+ and new or enlarging T2 lesions. Cox proportional hazards models were used to evaluate time to conversion to CDMS and MS (2005 McDonald criteria). This analysis focused primarily on the results for the cladribine tablets 3.5 mg/kg group because this dosage is approved for relapsing forms of MS.

RESULTS

In the overall intent-to-treat (ITT) population, cladribine tablets 3.5 mg/kg significantly reduced the risk of conversion to CDMS (hazard ratio [HR]=0.326; P<0.0001) and MS (2005 McDonald criteria; HR=0.485; P<0.0001) versus placebo. Similar effects of cladribine tablets on risk of conversion were observed in post hoc analyses of subgroups defined by various baseline characteristics. In both the ITT population and across subgroups, cladribine tablets 3.5 mg/kg reduced the numbers of cumulative T1 Gd+ (range of rate ratios: 0.106-0.399), new or enlarging T2 (range of rate ratios: 0.178-0.485), and CUA (range of rate ratios: 0.154-0.384) lesions versus placebo (all nominal P<0.03). Multivariate Cox proportional hazards models revealed that age (HR=0.577, nominal P<0.0001), FCDE classification (HR=0.738, nominal P=0.0043), presence of T1 Gd+ lesions (HR=0.554, nominal P<0.0001), and number of T2 lesions (HR=0.417, nominal P<0.0001) at baseline were factors associated with risk of conversion to MS (2005 McDonald criteria), whereas no baseline factors examined were associated with risk of conversion to CDMS.

CONCLUSION

In this post hoc analysis of the ORACLE-MS study, cladribine tablets reduced the risk of conversion to multiple sclerosis and lesion burden in participants with an FCDE in the overall ITT population and multiple subgroups defined by baseline demographics and lesion characteristics.

Cladribine inhibits secretion of pro-inflammatory cytokines and phagocytosis in human monocyte-derived M1 macrophages in-vitro

Cladribine (Cd) is a purine nucleoside analogue which in an oral formulation is approved for treatment of patients with multiple sclerosis (MS). It is known to mediate the effect through a short-term selective reduction of lymphocytes with minimal effect on the innate immune system. However, a few studies have emerged, that also demonstrate a beneficial immunomodulatory effect of cladribine on monocyte-derived cells. As cladribine crosses the blood-brain barrier this effect could have clinical meaningful impact in the treatment of MS, where recruitment of innate cells such as M1 macrophages play a role in plaque development. Here, we investigated the in-vitro effect on monocyte differentiation into M1 and M2 macrophages and dendritic cells as well as the effect on activation of M1 macrophages. In our experiments, cladribine in therapeutic relevant in-vitro concentrations, did not lead to apoptosis in differentiated M1, M2 macrophages or DCs and did not interfere with the phenotype of these differentiated cells. In M1 macrophages, cladribine reduced the secretion of IL-6 and TNF-α observed after activation with LPS. Similar, cladribine reduced the phagocytic capacity of LPS activated M1 macrophages but did not affect unactivated cells. We conclude, that such reduction of inflammatory potential as well as reduced M1 phagocytic activity, e.g. within an MS plaque, could be an additional clinical meaningful effect of cladribine in the treatment of MS while at the same time it would leave M1 macrophages intact for the protection against infections.

Ozanimod to Treat Relapsing Forms of Multiple Sclerosis: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators.

Severe lymphopenia after subcutaneous cladribine in a patient with multiple sclerosis: To vaccinate or not?

OBJECTIVE

To describe a fatal case of influenza A pneumonia in a patient with severe lymphopenia after receiving subcutaneous cladribine to treat her multiple sclerosis (MS).

METHODS

Case report.

RESULTS

A 53-year-old woman developed fatal influenza pneumonia associated with grade 4 lymphopenia two months after receiving a total dose of 60mg subcutaneous cladribine. Despite treatment with oseltamivir, her condition deteriorated and the patient passed away after developing respiratory failure.

CONCLUSION

Cladribine-related lymphopenia is usually mild to moderate, however severe lymphopenia may occur. People with MS, especially those who are immunosuppressed, should be offered the inactivated influenza vaccine annually.

Retinal cotton wool spot associated with cladribine therapy for multiple sclerosis

Cladribine has been shown to lower relapse rates and decrease disease progression in patients with relapsing forms of multiple sclerosis (MS). Reported adverse effects with use of cladribine include lymphopenia, neutropenia, and infections. Ocular complications have not previously been described with cladribine. We report the case of a patient developing visual symptoms and a large retinal cotton wool spot in association with initiation of cladribine therapy.

Urinary tract infections and multiple sclerosis: Recommendations from the French Multiple Sclerosis Society

OBJECTIVES

Establish recommendations for the management of UTIs in MS patients.

BACKGROUND

Urinary tract infections (UTIs) are common during multiple sclerosis (MS) and are one of the most common comorbidities potentially responsible for deaths from urinary sepsis.

METHODS

The recommendations attempt to answer three main questions about UTIs and MS. The French Group for Recommendations in MS (France4MS) did a systematic review of articles from PubMed and universities databases (01/1980-12/2019). The RAND/UCLA appropriateness method, which has been developed to synthesize the scientific literature and expert opinions on health care topics, was used for reaching a formal agreement. 26 MS experts worked on the full-text review and a group of 70 multidisciplinary health care specialists validated the final evaluation of summarized evidences.

RESULTS

UTIs are not associated with an increased risk of relapse and permanent worsening of disability. Only febrile UTIs worsen transient disability through the Uhthoff phenomenon. Some immunosuppressive treatments increase the risk of UTIs in MS patients and require special attention especially in case of hypogammaglobulinemia. Experts recommend to treat UTIs in patients with MS, according to recommendations of the general population. Prevention of recurrent UTIs requires stabilization of the neurogenic bladder. In some cases, weekly oral cycling antibiotics can be proposed after specialist advice. Asymptomatic bacteriuria should not be screened for or treated systematically except in special cases (pregnancy and invasive urological procedures).

CONCLUSION

Physicians and patients should be aware of the updated recommendations for UTis and MS.

Medicinal Chemistry of Multiple Sclerosis: Focus on Cladribine

BACKGROUND

In the recent years, many novel Disease-Modifying Drugs (DMD) have been introduced to the market in the treatment of multiple sclerosis.

OBJECTIVES

To provide the reader with an up to date, compact review on the pharmacokinetic properties, mechanism of action, and clinical attributes of one of the most recently approved drugs in the therapy of multiple sclerosis, cladribine.

CONCLUSION

Cladribine tablets proved to be a highly efficient treatment choice for Relapsing- Remitting Multiple Sclerosis (RRMS), especially for patients with high disease activity. It is the first DMD for MS with a complex mechanism of action, by inhibiting the adenosine-deaminase enzyme it increases the intracellular levels of deoxyadenosine triphosphate, which with relative selectivity depletes both T- and B-cells lines simultaneously. However long term follow-up safety and effectiveness data are still missing, and clear treatment protocols are lacking beyond the first two treatment years cladribine should prove to be a valuable addition to the therapeutic palette of RRMS, and potentially for Clinically Isolated Syndrome (CIS) as well.

Long-term peripheral immune cell profiling reveals further targets of oral cladribine in MS

OBJECTIVES

To expand the knowledge about the immunological consequences of cladribine (CLAD), a pulsed immune reconstitution therapy approved for active multiple sclerosis (MS), beyond the known short-term effects on peripheral immune cell subsets.

METHODS

In this study, we characterized depletion and restitution kinetics as well as cytokine profiles of peripheral immune cell subsets in 18 patients with MS following treatment with oral CLAD. The methods involved blood collection prior to CLAD and every three months over a period of 24 months, and extensive characterization of various immune cells subsets by multiparametric flow cytometry.

RESULTS

We found a selectivity of CLAD towards central memory T cells and memory B cells and detected a hyper-repopulation of maturing B cells. Counts of classical (-65%) and various nonclassical TH17 cells (-84% to -87%) were markedly reduced 24 months after treatment start, and were comparable with depletion rates of class-switched memory B-cell phenotypes (-87% to -95%). The nadir of TH cells was more pronounced in the second treatment year. We observed a proportional surge of CD20 T-cell subsets and an expansion of regulatory T, B and NK cells. Natural killer T cells (NKT) were only depleted in year two and did not recover.

INTERPRETATION

Peripheral immune cell profiling revealed more differentiated insights into the immunological effects of CLAD. While some immune cell subsets expanded, we also observed additive depleting effects after the second treatment course. Further studies are required to elucidate whether these changes are paramount for the consistent and prolonged disease-modifying effect of CLAD.

The risk of infection in patients with multiple sclerosis treated with disease-modifying therapies: A Delphi consensus statement

The risk of infection associated with immunomodulatory or immunosuppressive disease-modifying drugs (DMDs) in patients with multiple sclerosis (MS) has been increasingly addressed in recent scientific literature. A modified Delphi consensus process was conducted to develop clinically relevant, evidence-based recommendations to assist physicians with decision-making in relation to the risks of a wide range of infections associated with different DMDs in patients with MS. The current consensus statements, developed by a panel of experts (neurologists, infectious disease specialists, a gynaecologist and a neuroradiologist), address the risk of iatrogenic infections (opportunistic infections, including herpes and cryptococcal infections, candidiasis and listeria; progressive multifocal leukoencephalopathy; human papillomavirus and urinary tract infections; respiratory tract infections and tuberculosis; hepatitis and gastrointestinal infections) in patients with MS treated with different DMDs, as well as prevention strategies and surveillance strategies for the early identification of infections. In the discussion, more recent data emerged in the literature were taken into consideration. Recommended risk reduction and management strategies for infections include screening at diagnosis and before starting a new DMD, prophylaxis where appropriate, monitoring and early diagnosis.

[Comparison of the clinical benefits of second-line drugs modifying the course of multiple sclerosis]

This review aims at describing clinical benefits and characteristics of the main highly effective disease modifying drugs (DMD) for multiple sclerosis (MS): alemtuzumab, cladribine tablets, ocrelizumab, natalizumab, fingolimod based on the efficacy and safety. The authors highlight that all MS DMDs have certain benefits and features that shall be considered in prescribing pharmacotherapy. Cladribine in tablets are comparable by the efficacy to other modern highly effective second-line drugs, have a high level of evidence and a favorable safety profile, as well as the most preferred benefit/risk ratio among other MS DMDs indicated for the treatment of highly active MS, which offers an advantage to the drug. The use of cladribine in tablets will contribute to further study of the efficacy and safety of this highly efficient drug for MS treatment.

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.