COVID-19 in cladribine-treated relapsing-remitting multiple sclerosis patients: a monocentric experience

A multi-centre longitudinal study analysing multiple sclerosis disease-modifying therapy prescribing patterns during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic raised concern amongst clinicians that disease-modifying therapies (DMT), particularly anti-CD20 monoclonal antibodies (mAb) and fingolimod, could worsen COVID-19 in people with multiple sclerosis (pwMS). This study aimed to examine DMT prescribing trends pre- and post-pandemic onset.

METHODS

A multi-centre longitudinal study with 8,771 participants from MSBase was conducted. Two time periods were defined: pre-pandemic (March 11 2018-March 10 2020) and post-pandemic onset (March 11 2020-11 March 2022). The association between time and prescribing trends was analysed using multivariable mixed-effects logistic regression. DMT initiation refers to first initiation of any DMT, whilst DMT switches indicate changing regimen within 6 months of last use.

RESULTS

Post-pandemic onset, there was a significant increase in DMT initiation/switching to natalizumab and cladribine [(Natalizumab-initiation: OR 1.72, 95% CI 1.39-2.13; switching: OR 1.66, 95% CI 1.40-1.98), (Cladribine-initiation: OR 1.43, 95% CI 1.09-1.87; switching: OR 1.67, 95% CI 1.41-1.98)]. Anti-CD20mAb initiation/switching decreased in the year of the pandemic, but recovered in the second year, such that overall odds increased slightly post-pandemic (initiation: OR 1.26, 95% CI 1.06-1.49; Switching: OR 1.15, 95% CI 1.02-1.29. Initiation/switching of fingolimod, interferon-beta, and alemtuzumab significantly decreased [(Fingolimod-initiation: OR 0.55, 95% CI 0.41-0.73; switching: OR 0.49, 95% CI 0.41-0.58), (Interferon-gamma-initiation: OR 0.48, 95% CI 0.41-0.57; switching: OR 0.78, 95% CI 0.62-0.99), (Alemtuzumab-initiation: OR 0.27, 95% CI 0.15-0.48; switching: OR 0.27, 95% CI 0.17-0.44)].

CONCLUSIONS

Post-pandemic onset, clinicians preferentially prescribed natalizumab and cladribine over anti-CD20 mAbs and fingolimod, likely to preserve efficacy but reduce perceived immunosuppressive risks. This could have implications for disease progression in pwMS. Our findings highlight the significance of equitable DMT access globally, and the importance of evidence-based decision-making in global health challenges.

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.

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

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

Vaccination Opportunities in Multiple Sclerosis Patients Treated with Cladribine Tablets

COVID 19 pandemic and mass vaccination campaigns have revealed the situation of the most vulnerable patients. In this work, we focused our attention to patients who have Multiple Sclerosis (MS), particularly in treatment with cladribine tablets, trying to understand if and when it is possible to administer the vaccine successfully. In light of the novel topic, we studied the existing literature and analysed experiences with previous vaccinations, such as influenza and VZV, as well as data from countries where vaccination campaigns had already begun. Overall, we have taken into account the mechanism of action, the pharmacokinetic/pharmacodynamic of cladribine, and the changes in the immune system after its administration, together with the preliminary data about the humoral response to influenza, VZV, and SARS-CoV-2 vaccinations in cladribine treated patients. In conclusion, data showed that the use of cladribine tablets seems to permit flexibility regarding vaccination timing and we suggest that vaccination in those patients should be safe and effective. The current COVID 19 pandemic has re-ignited the interest in vaccines and vaccination procedures. The importance of including fragile individuals has increased as a result of mass vaccination. Millions of patients with multiple sclerosis (MS) around the world are debating whether they can safely receive their vaccine shot with the same efficacy despite receiving immune-modulating or immune-suppressive treatments. In the absence of conclusive empirical data, we will review and discuss the available evidence and the reasonable conclusions for one specific treatment, namely cladribine tablets (Mavenclad).

Multiple Sclerosis Patients and Disease Modifying Therapies: Impact on Immune Responses against COVID-19 and SARS-CoV-2 Vaccination

This article reviews the literature on SARS-CoV-2 pandemic and multiple sclerosis (MS). The first part of the paper focuses on the current data on immunopathology of SARS-CoV-2 and leading vaccines produced against COVID-19 infection. In the second part of the article, we discuss the effect of Disease Modifying Therapies (DMTs) on COVID-19 infection severity or SARS-CoV-2 vaccination in MS patients plus safety profile of different vaccine platforms in MS patients.

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.

HUMORAL RESPONSE TO SARS-CoV-2 AND COVID-19 VACCINES IN PATIENTS WITH MULTIPLE SCLEROSIS TREATED WITH IMMUNE RECONSTITUTION THERAPIES

Background

It has been generally accepted that people with MS (PwMS) should be vaccinated against COVID-19. The aim of our investigation was to evaluate the humoral response to natural SARS-CoV-2 infection and to two COVID-19 vaccines (BNT162b2 Pfizer-BioNTech and Beijing/Sinopharm BBIBP-CorV) in our cohort of PwMS under high efficacy disease modifying therapies (DMTs), cladribine and alemtuzumab.

Methods

Twenty two PwMS treated at the Clinic of Neurology, in Belgrade, who developed COVID-19 and/or were vaccinated against SARS-CoV-2, during treatment with cladribine and alemtuzumab, were included. Out of 18 patients treated with cladribine, 11 developed COVID-19, and 11 were vaccinated against SARS-CoV-2 (four with mRNA vaccine, 7 with Sinopharm). Four MS patients under alemtuzumab were vaccinated against SARS-CoV-2; three with mRNA, and one with Sinopharm vaccine. SARS-Cov-2 IgG response was measured using ELISA anti-spike protein-based serology (INEP, Belgrade, Serbia).

Results

All 7 patients under cladribine treatment who suffered from COVID-19, developed IgG antibodies, 2.0-5.5 months after last symptoms. All four (100%) patients under cladribine who were vaccinated with Pfizer-BioNTech vaccine, and three out of seven (42.9%) vaccinated with Sinopharm, developed antibodies. All 4 patients under alemtuzumab developed antibodies after vaccination. In all cases, seroprotection occurred, irrespective of timing of vaccination and absolute lymphocyte count.

Conclusion

Our findings in a small number of highly active PwMS in whom, lymphodepleting, immune reconstitution therapies, were applied in order to successfully manage MS, indicate that in a number of these patients it was possible to develop at the same time seroprotection in these patients after COVID-19 vaccination in these complex circumstances.

Multiple Sclerosis, Disease-Modifying Therapies and COVID-19: A Systematic Review on Immune Response and Vaccination Recommendations

Understanding the risks of COVID-19 in patients with Multiple Sclerosis (MS) receiving disease-modifying therapies (DMTs) and their immune reactions is vital to analyze vaccine response dynamics. A systematic review on COVID-19 course and outcomes in patients receiving different DMTs was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Emerging data on SARS-CoV-2 vaccines was used to elaborate recommendations. Data from 4417 patients suggest that MS per se do not portend a higher risk of severe COVID-19. As for the general population, advanced age, comorbidities, and higher disability significantly impact COVID-19 outcomes. Most DMTs have a negligible influence on COVID-19 incidence and outcome, while for those causing severe lymphopenia and hypogammaglobulinemia, such as anti-CD20 therapies, there might be a tendency of increased hospitalization, worse outcomes and a higher risk of re-infection. Blunted immune responses have been reported for many DMTs, with vaccination implications. Clinical evidence does not support an increased risk of MS relapse or vaccination failure, but vaccination timing needs to be individually tailored. For cladribine and alemtuzumab, it is recommended to wait 3-6 months after the last cycle until vaccination. For the general anti-CD20 therapies, vaccination must be deferred toward the end of the cycle and the next dose administered at least 4-6 weeks after completing vaccination. Serological status after vaccination is highly encouraged. Growing clinical evidence and continuous surveillance are extremely important to continue guiding future treatment strategies and vaccination protocols.

The Significance of COVID-19 Immunological Status in Severe Neurological Complications and Multiple Sclerosis-A Literature Review

SARS-CoV-2/Coronavirus 2019 (COVID-19) is responsible for the pandemic, which started in December 2019. In addition to the typical respiratory symptoms, this virus also causes other severe complications, including neurological ones. In diagnostics, serological and polymerase chain reaction tests are useful not only in detecting past infections but can also predict the response to vaccination. It is now believed that an immune mechanism rather than direct viral neuroinvasion is responsible for neurological symptoms. For this reason, it is important to assess the presence of antibodies not only in the serum but also in the cerebrospinal fluid (CSF), especially in the case of neuro-COVID. A particular group of patients are people with multiple sclerosis (MS) whose disease-modifying drugs weaken the immune system and lead to an unpredictable serological response to SARS-CoV-2 infection. Based on available data, the article summarizes the current serological information concerning COVID-19 in CSF in patients with severe neurological complications and in those with MS.

COVID-19 in patients with multiple sclerosis treated with cladribine tablets: An update

Background

We previously summarized outcomes for 46 cladribine tablets (CladT)-treated patients with multiple sclerosis (MS) and confirmed or suspected COVID-19, as reported to the Merck KGaA Global Patient Safety Database. This report updates on these findings, to 15 January 2021, for a total of 272 reported cases of COVID-19 among CladT recipients.

Methods

Case definitions: confirmed (COVID-19 diagnostic test was positive); suspected (no confirmatory test performed/reported). Cases fulfilling the criteria of hospitalized, medically significant, or fatal were designated as serious and outcomes were classified per usual pharmacovigilance practice.

Results

The evaluable cohort comprised 261 patients (confirmed COVID-19, n=160; suspected, n=101); an additional 11 patients had symptoms compatible with COVID-19 but were not evaluated further given their negative diagnostic tests. Median time to onset of COVID-19 from the most recent preceding CladT treatment course was 162 days (n=139). Outcomes were: recovered/recovering, n=133 (51%); not recovered/not resolved, n=19 (7%); died, n=1 (0.4%); and not reported/missing/pending, n=108 (41%). Of the total cohort, 40 (15%) experienced serious COVID-19.

Conclusion

Our results suggest that CladT-treated patients with MS are generally not at greater risk of serious disease and/or a severe outcome with COVID-19 compared with the general population and other patients with MS who acquired COVID-19.