Humoral immune response and lymphocyte levels after complete vaccination against COVID-19 in a cohort of multiple sclerosis patients treated with cladribine tablets

Humoral immune response after SARS-CoV-2 vaccination in cladribine-treated multiple sclerosis patients

Multiple sclerosis immunomodulatory treatments such as cladribine, which affects both B- and T-lymphocytes, can potentially alter the humoral response to SARS-CoV-2 vaccination. This monocenter retrospective study reports on anti-SARS-CoV-2 IgG antibody response in cladribine treated MS patients and we compare the response in patients vaccinated before and after an 18-week interval after last cladribine dose. Of the 34 patients (5 patients ≤ 18 weeks and 29 patients > 18 weeks after last cladribine dose) that were included, 32 reached seropositivity (94 %). All patients vaccinated < 18 weeks after last cladribine dose reached seropositivity. This study confirms findings of earlier reports that cladribine-treated MS patients show an adequate humoral response after SARS-CoV-2 vaccination, even when vaccinated early (≤18 weeks) after last cladribine dose.

The impact of hybrid immunity on immune responses after SARS-CoV-2 vaccination in persons with multiple sclerosis treated with disease-modifying therapies

BACKGROUND AND PURPOSE

Hybrid immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develops from a combination of natural infection and vaccine-generated immunity. Multiple sclerosis (MS) disease-modifying therapies (DMTs) have the potential to impact humoral and cellular immunity induced by SARS-CoV-2 vaccination and infection. The aims were to compare antibody and T-cell responses after SARS-CoV-2 mRNA vaccination in persons with MS (pwMS) treated with different DMTs and to assess differences between naïvely vaccinated pwMS and pwMS with hybrid immunity vaccinated following a previous SARS-CoV-2 infection.

METHODS

Antibody and T-cell responses were determined in pwMS at baseline and 4 and 12 weeks after the second dose of SARS-CoV-2 vaccination in 143 pwMS with or without previous SARS-CoV-2 infection and 40 healthy controls (HCs). The MS cohort comprised natalizumab (n = 22), dimethylfumarate (n = 23), fingolimod (n = 38), cladribine (n = 30), alemtuzumab (n = 17) and teriflunomide (n = 13) treated pwMS. Immunoglobulin G antibody responses to SARS-CoV-2 antigens were measured using a multiplex bead assay and FluoroSpot was used to assess T-cell responses (interferon γ and interleukin 13).

RESULTS

Humoral and T-cell responses to vaccination were comparable between naïvely vaccinated HCs and pwMS treated with natalizumab, dimethylfumarate, cladribine, alemtuzumab and teriflunomide, but were suppressed in fingolimod-treated pwMS. Both fingolimod-treated pwMS and HCs vaccinated following a previous SARS-CoV-2 infection had higher antibody levels 4 weeks after vaccination compared to naïvely vaccinated individuals. Antibody and interferon γ levels 12 weeks after vaccination were positively correlated with time from last treatment course of cladribine.

CONCLUSION

These findings are of relevance for infection risk mitigation and for vaccination strategies amongst pwMS undergoing DMT.

Cladribine Tablets Mode of Action, Learning from the Pandemic: A Narrative Review

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system, characterized by chronic, inflammatory, demyelinating, and neurodegenerative processes. MS management relies on disease-modifying drugs that suppress/modulate the immune system. Cladribine tablets (CladT) have been approved by different health authorities for patients with various forms of relapsing MS. The drug has been demonstrated to deplete CD4+ and CD8+ T-cells, with a higher effect described in the former, and to decrease total CD19+, CD20+, and naive B-cell counts. COVID-19 is expected to become endemic, suggesting its potential infection risk for immuno-compromised patients, including MS patients treated with disease-modifying drugs. We report here the available data on disease-modifying drug-treated-MS patients and COVID-19 infection and vaccination, with a focus on CladT. MS patients treated with CladT are not at higher risk of developing severe COVID-19. While anti-SARS-CoV-2 vaccination is recommended in all MS patients with guidelines addressing vaccination timing according to the different disease-modifying drugs, no vaccination timing restrictions seem to be necessary for cladribine, based on its mechanism of action and available evidence. Published data suggest that CladT treatment does not impact the production of anti-SARS-CoV-2 antibodies after COVID-19 vaccination, possibly due to its relative sparing effect on naïve B-cells and the rapid B-cell reconstitution following treatment. Slightly lower specific T-cell responses are likely not impacting the risk of breakthrough COVID-19. It could be stated that cladribine's transient effect on innate immune cells likely contributes to maintaining an adequate first line of defense against the SARS-CoV-2 virus.

Multiple sclerosis patients treated with cladribine tablets: expert opinion on practical management after year 4

Multiple sclerosis (MS) is a chronic, progressive neurological disease involving neuroinflammation, neurodegeneration, and demyelination. Cladribine tablets are approved for immune reconstitution therapy in patients with highly active relapsing-remitting MS based on favorable efficacy and tolerability results from the CLARITY study that have been confirmed in long-term extension studies. The approved 4-year dosing regimen foresees a cumulative dose of 3.5 mg/kg administered in two cycles administered 1 year apart, followed by 2 years of observation. Evidence on managing patients beyond year 4 is scarce; therefore, a group of 10 neurologists has assessed the available evidence and formulated an expert opinion on management of the growing population of patients now completing the approved 4-year regimen. We propose five patient categories based on response to treatment during the first 4-year regimen, and corresponding management pathways that envision close monitoring with clinical visits, magnetic resonance imaging (MRI) and/or biomarkers. At the first sign of clinical or radiological disease activity, patients should receive a highly effective disease-modifying therapy, comprising either a full cladribine regimen as described in regulatory documents (cumulative dose 7.0 mg/kg) or a comparably effective treatment. Re-treatment decisions should be based on the intensity and timing of onset of disease activity, clinical and radiological assessments, as well as patient eligibility for treatment and treatment preference.

ECTRIMS/EAN consensus on vaccination in people with multiple sclerosis: Improving immunization strategies in the era of highly active immunotherapeutic drugs

BACKGROUND

With the new highly active drugs available for people with multiple sclerosis (pwMS), vaccination becomes an essential part of the risk management strategy.

OBJECTIVE

To develop a European evidence-based consensus for the vaccination strategy of pwMS who are candidates for disease-modifying therapies (DMTs).

METHODS

This work was conducted by a multidisciplinary working group using formal consensus methodology. Clinical questions (defined as population, interventions, and outcomes) considered all authorized DMTs and vaccines. A systematic literature search was conducted and quality of evidence was defined according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. The recommendations were formulated based on the quality of evidence and the risk-benefit balance.

RESULTS

Seven questions, encompassing vaccine safety, vaccine effectiveness, global vaccination strategy and vaccination in sub-populations (pediatric, pregnant women, elderly and international travelers) were considered. A narrative description of the evidence considering published studies, guidelines, and position statements is presented. A total of 53 recommendations were agreed by the working group after three rounds of consensus.

CONCLUSION

This first European consensus on vaccination in pwMS proposes the best vaccination strategy according to current evidence and expert knowledge, with the goal of homogenizing the immunization practices in pwMS.

Safety, immunogenicity, efficacy, and acceptability of COVID-19 vaccination in people with multiple sclerosis: a narrative review

In the last two years, a new severe acute respiratory syndrome coronavirus (SARS-CoV) infection has spread worldwide leading to the death of millions. Vaccination represents the key factor in the global strategy against this pandemic, but it also poses several problems, especially for vulnerable people such as patients with multiple sclerosis. In this review, we have briefly summarized the main findings of the safety, efficacy, and acceptability of Coronavirus Disease 2019 (COVID-19) vaccination for multiple sclerosis patients. Although the acceptability of COVID-19 vaccines has progressively increased in the last year, a small but significant part of patients with multiple sclerosis still has relevant concerns about vaccination that make them hesitant about receiving the COVID-19 vaccine. Overall, available data suggest that the COVID-19 vaccination is safe and effective in multiple sclerosis patients, even though some pharmacological treatments such as anti-CD20 therapies or sphingosine l-phosphate receptor modulators can reduce the immune response to vaccination. Accordingly, COVID-19 vaccination should be strongly recommended for people with multiple sclerosis and, in patients treated with anti-CD20 therapies and sphingosine l-phosphate receptor modulators, and clinicians should evaluate the appropriate timing for vaccine administration. Further studies are necessary to understand the role of cellular immunity in COVID-19 vaccination and the possible usefulness of booster jabs. On the other hand, it is mandatory to learn more about the reasons why people refuse vaccination. This would help to design a more effective communication campaign aimed at increasing vaccination coverage among vulnerable people.

Expert-Agreed Practical Recommendations on the Use of Cladribine

Cladribine is a disease-modifying selective immune reconstitution oral therapy for adult patients with highly active relapsing multiple sclerosis (RMS). It was approved in the USA in 2019 and in Europe in 2017, thus there are still gaps in existing guidelines for using cladribine tablets in clinical practice. Nine experts with extensive experience in managing patients with multiple sclerosis in Spain identified some of the unanswered questions related to the real-life use of cladribine tablets. They reviewed the available clinical trial data and real-world evidence, including their own experiences of using cladribine, over the course of three virtual meetings held between November 2020 and January 2021. This article gathers their practical recommendations to aid treatment decision-making and optimise the use of cladribine tablets in patients with RMS. The consensus recommendations cover the following areas: candidate patient profiles, switching strategies (to and from cladribine), managing response to cladribine and safety considerations.

Multiple sclerosis disease-modifying therapies and COVID-19 vaccines: a practical review and meta-analysis

Studies among people with multiple sclerosis (pwMS) receiving disease-modifying therapies (DMTs) have provided adequate evidence for an appraisal of COVID-19 vaccination policies among them. To synthesise the available evidence addressing the effect of MS DMTs on COVID-19 vaccines' immunogenicity and effectiveness, following the Cochrane guidelines, we systematically reviewed all observational studies available in MEDLINE, Scopus, Web of Science, MedRxiv and Google Scholar from January 2021 to January 2022 and extracted their relevant data. Immunogenicity data were then synthesised in a quantitative, and other data in a qualitative manner. Evidence from 28 studies suggests extensively lower B-cell responses in sphingosine-1-phosphate receptor modulator (S1PRM) treated and anti-CD20 (aCD20) treated, and lower T-cell responses in interferon-treated, S1PRM-treated and cladribine-treated pwMS-although most T cell evidence currently comprises of low or very low certainty. With every 10-week increase in aCD20-to-vaccine period, a 1.94-fold (95% CI 1.57 to 2.41, p<0.00001) increase in the odds of seroconversion was observed. Furthermore, the evidence points out that B-cell-depleting therapies may accelerate postvaccination humoral waning, and boosters' immunogenicity is predictable with the same factors affecting the initial vaccination cycle. Four real-world studies further indicate that the comparative incidence/severity of breakthrough COVID-19 has been higher among the pwMS treated with S1PRM and aCD20-unlike the ones treated with other DMTs. S1PRM and aCD20 therapies were the only DMTs reducing the real-world effectiveness of COVID-19 vaccination among pwMS. Hence, it could be concluded that optimisation of humoral immunogenicity and ensuring its durability are the necessities of an effective COVID-19 vaccination policy among pwMS who receive DMTs.

Long-term management of multiple sclerosis patients treated with cladribine tablets beyond year 4

INTRODUCTION

Oral cladribine is a highly effective pulsed selective immune reconstitution therapy licensed for relapsing multiple sclerosis (RMS) since 2017. A full treatment course comprises two treatment cycles given 1 year apart, followed by two treatment-free years. The management of cladribine-treated patients beyond year 4 needs to be addressed as patients have now passed the initial 4 years since European Medical Agency approval.

AREAS COVERED

A panel of neurologists and a neuroradiologist experienced in MS treatment/monitoring evaluated clinical trial data and real-world evidence and proposed recommendations for the management of cladribine-treated patients beyond year 4.

EXPERT OPINION

Continuous monitoring of disease activity during the treatment-free period is important. Subsequent management depends on the presence or absence of inflammatory disease activity, determined in the absence of consistent guidelines via practice-driven neurological decision criteria. Persisting or newly occurring inflammatory disease activity is an indication for further treatment, i.e. either re-initiation of cladribine or switching to another highly effective disease-modifying therapy. The decision to retreat or switch should be based on clinical and radiological evaluation considering disease course, treatment history, and safety aspects. In the absence of disease activity, either retreatment can be offered, or the treatment-free period can be extended under structured monitoring.

Immune responses to SARS-CoV-2 vaccination in multiple sclerosis: a systematic review/meta-analysis

INTRODUCTION

Responses to SARS-CoV-2 vaccination in patients with MS (pwMS) varies by disease-modifying therapies (DMTs). We perform a meta-analysis and systematic review of immune response to SARS-CoV-2 vaccines in pwMS.

METHODS

Two independent reviewers searched PubMed, Google Scholar, and Embase from January 1, 2019-December 31, 2021, excluding prior SARS-CoV-2 infections. The meta-analysis of observational studies in epidemiology (MOOSE) guidelines were applied. The data were pooled using a fixed-effects model.

RESULTS

Eight-hundred sixty-four healthy controls and 2203 pwMS from 31 studies were included. Antibodies were detected in 93% healthy controls (HCs), and 77% pwMS, with >93% responses in all DMTs (interferon-beta, glatiramer acetate, cladribine, natalizumab, dimethyl fumarate, alemtuzumab, and teriflunomide) except for 72% sphingosine-1-phosphate modulators (S1PM) and 44% anti-CD20 monoclonal antibodies (mAbs). T-cell responses were detected in most anti-CD20 and decreased in S1PM. Higher antibody response was observed in mRNA vaccines (99.7% HCs) versus non-mRNA vaccines (HCs: 72% inactivated virus; pwMS: 86% vector, 59% inactivated virus). A multivariate logistic regression model to predict vaccine response demonstrated that mRNA versus non-mRNA vaccines had a 3.4 odds ratio (OR) for developing immunity in anti-CD20 (p = 0.0052) and 7.9 OR in pwMS on S1PM or CD20 mAbs (p < 0.0001). Antibody testing timing did not affect antibody detection.

CONCLUSION

Antibody responses are decreased in S1PM and anti-CD20; however, cellular responses were positive in most anti-CD20 with decreased T cell responses in S1PM. mRNA vaccines had increased seroconversion rates compared to non-RNA vaccines. Further investigation in how DMTs affect vaccine immunity are needed.

Longitudinal humoral response in MS patients treated with cladribine tablets after receiving the second and third doses of SARS-CoV-2 mRNA vaccine

BACKGROUND

Multiple sclerosis (MS) patients receive immunomodulatory treatments which can influence their ability to maintain vaccine specific serological response overtime. MS patients treated with cladribine tablets developed a positive serology response following two doses of mRNA COVID-19 vaccine. However, there is only limited data regarding the effect of cladribine tablets on long-term humoral response after the second and the third booster.

METHODS

Serology response to SARS-CoV-2 was tested in healthy controls (HCs) and MS patients treated with cladribine tablets 6 and 9-12 months after the second dose, and 1 and 3-6 months following the third booster-dose of the BTN162b2 mRNA vaccine.

RESULTS

Thirty-five out of 36 MS patients treated with cladribine tablets and 100% (46/46) of HCs had a positive serology response up to 10 months after the second vaccine dose. In addition, all cladribine tablets -treated MS patients (22/22) and HCs (24/24) had a positive robust serology response following the third vaccine with a positive humoral response sustain up to 6 months. One month after the third vaccine dose IgG levels were significantly lower in patients treated with cladribine tablets compared to HCs (15,598+11,313 vs 26,394+11,335, p<0.01). Six-month post second vaccine and 3-6 months post third vaccine there was no difference in IgG levels between the groups (1088.0 ± 1072.0 vs 1153.0 ± 997.1, p = 0.79; 5234+4097 vs 11,198+14,679, p = 0.4).

CONCLUSION AND RELEVANCE

MS patients treated with cladribine tablets have sustained positive vaccine specific serology response following the second and third SARS-CoV-2 vaccine dose.

Multiple sclerosis in the era of COVID-19: disease course, DMTs and SARS-CoV2 vaccinations

PURPOSE OF REVIEW

As of January 21st 2022, over 340 million are confirmed cases of coronavirus disease 2019 (COVID-19), including nearly 5.6 million deaths. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is neurotropic and affects the neural parenchyma through direct viral invasion from the nasal mucosa and postinfectious cytokine storm. Further challenges of SARS-CoV-2 infection are nowadays linked to variants of concern. Multiple sclerosis is an inflammatory and progressive degenerative disorder of the central nervous system commonly affecting young adults and potentially generating irreversible disability. Since the beginning of the SARS-CoV-2 pandemic, people with multiple sclerosis (pwMS) have been considered 'extra' vulnerable because of the immune-mediated nature of the disease, the disability status, and the immunomodulatory therapies potentially increasing the risk for viral infection. Today multiple sclerosis neurologists are faced with several challenges in the management of pwMS to both prevent SARS-CoV-2 infection and protection from disease worsening. We aimed to highlight today's most relevant facts about the complex management of pwMS in the COVID-19 era.

RECENT FINDINGS

The incidence of COVID-19 among pwMS does not differ from the general population. The prognosis of COVID-19 among pwMS is driven by older age, male sex, nonambulatory status, comorbidity as in the general population, as well as by corticosteroid treatment and B-cell depleting agents which decrease seropositivity from SARS-CoV-2 infection and immune responses to SARS-CoV-2 vaccination.

SUMMARY

Disease modifying treatments (DMTs) should be regularly continued in relation to SARS-CoV-2 vaccination, but an ad hoc timing is required with B-cell depleting agents. SARS-CoV-2 vaccination is recommended in pwMS with willingness improving through health education programs. Multiple sclerosis does not seem to worsen after SARS-Cov2 vaccination but COVID-19 may enhance disease activity.

Real-world evidence for cladribine tablets in multiple sclerosis: further insights into efficacy and safety

Cladribine (CLAD) is a purine nucleoside analog approved in tablet form to treat highly active multiple sclerosis (MS). CLAD tablets are the first oral therapy with an infrequent dosing schedule, administered in two annual treatment courses, each divided into two treatment cycles comprising 4–5 days of treatment. The efficacy and safety of CLAD tablets have been verified in randomized controlled clinical trials. Clinical observational studies are performed in more representative populations and over more extended periods, and thus provide valuable complementary insights. Here, we summarize the available evidence for CLAD tablets from post-marketing trials, including two observational, four long-term extensions, and two comparative studies. The patients in the post-marketing setting differed from the cohort recruited in the pivotal phase III trials regarding demographics and MS-related disability. The limited number of studies with small cohorts corroborate the disease-modifying capacity of oral CLAD and report on a durable benefit after active treatment periods. Skin-related adverse events were common in the studies focusing on safety aspects. In addition, single cases of CLAD-associated autoimmune events have been reported. Lastly, CLAD tablets appear safe regarding COVID-19 concerns, and patients mount a robust humoral immune response to SARS-CoV‑2 vaccination. We conclude that the current real-world evidence for CLAD tablets as immune reconstitution therapy for treatment of MS is based on a small number of studies and a population distinct from the cohorts randomized in the pivotal phase III trials. Further research should advance the understanding of long-term disease control after active treatment periods and the mitigation of adverse events.