Determining the best window for BNT162b2 mRNA vaccination for SARS-CoV-2 in patients with multiple sclerosis receiving anti-CD20 therapy

Efficacy of Rituximab Outlasts B-Cell Repopulation in Multiple Sclerosis: Time to Rethink Dosing?

BACKGROUND AND OBJECTIVES

Patients with multiple sclerosis (PwMS) receiving extended dosing of rituximab (RTX) have exhibited no return of disease activity, which suggests that maintenance of deep depletion of circulating B cells is not necessary to maintain the efficacy of RTX in MS.

METHODS

This was a prospective monocentric observational study including all consecutive PwMS who started or continued RTX after 2019, when the medical staff decided to extend the dosing interval up to 24 months for all patients. Circulating B-cell subsets were monitored regularly and systematically in case of relapse. The first extended interval was analyzed.

RESULTS

We included 236 PwMS (81% with relapsing-remitting MS; mean [SD] age 43 [12] years; median [range] EDSS score 4 [0-8]; mean relapse rate during the year before RTX start 1.09 [0.99]; 41.5% with MRI activity). The median number of RTX infusions before extension was 4 (1-13). At the time of the analysis, the median delay in dosing was 17 months (8-39); the median proportion of circulating CD19+ B cells was 7% (0-25) of total lymphocytes and that of CD27+ memory B cells was 4% (0-16) of total B cells. The mean annual relapse rate did not differ before and after the extension: 0.03 (0.5) and 0.04 (0.15) (p = 0.51). Similarly, annual relapse rates did not differ before and after extension in patients with EDSS score ≤3 (n = 79) or disease duration ≤5 years (n = 71) at RTX onset. During the "extended dosing" period, MRI demonstrated no lesion accrual in 228 of the 236 patients (97%). Five patients experienced clinical relapse, which was confirmed by MRI. In these patients, the level of B-cell subset reconstitution at the time of the relapse did not differ from that for patients with the same extension window.

DISCUSSION

The efficacy of RTX outlasted substantial reconstitution of circulating B cells in PwMS, which suggests that renewal of the immune system underlies the prolonged effect of RTX in MS. These findings suggest that extended interval dosing of RTX that leads to a significant reconstitution of circulating B cells is safe in PwMS, could reduce the risk of infection, and could improve vaccine efficacy.

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.

B cell repopulation dynamics and drug pharmacokinetics impact SARS-CoV-2 vaccine efficacy in anti-CD20-treated multiple sclerosis patients

BACKGROUND

Recent findings document a blunted humoral response to SARS-CoV-2 vaccination in patients on anti-CD20 treatment. Although most patients develop a cellular response, it is still important to identify predictors of seroconversion in order to optimize vaccine responses.

METHODS

We determined antibody responses after SARS-CoV-2 vaccination in a real-world cohort of multiple sclerosis patients (n = 94) treated with anti-CD20, mainly rituximab, with variable treatment duration (median 2.9; range 0.4-9.6 years) and time from last anti-CD20 infusion to vaccination (median 190; range 60-1032 days).

RESULTS

We find that presence of B cells and/or rituximab in blood predict seroconversion better than time since last infusion. Using multiple logistic regression, presence of >0.5% B cells increased probability for seroconversion with an odds ratio (OR) of 5.0 (CI 1.0-28.1, p = 0.055), while the corresponding OR for ≥ 6 months since last infusion was 1.45 (CI 0.20-10.15, p = 0.705). In contrast, detectable rituximab levels were negatively associated with seroconversion (OR 0.05; CI 0.002-0.392, p = 0.012). Furthermore, naïve and memory IgG⁺ B cells correlated with antibody levels. Although re-treatment with rituximab at four weeks or more after booster depleted spike-specific B cells, it did not noticeably affect the rate of decline in antibody titers. Interferon-γ and/or interleukin-13 T cell responses to the spike S1 domain were observed in most patients, but with no correlation to spike antibody levels.

CONCLUSIONS

These findings are relevant for providing individualized guidance to patients and planning of vaccination schemes, in turn optimizing benefit-risk with anti-CD20.

Persistently reduced humoral and sustained cellular immune response from first to third SARS-CoV-2 mRNA vaccination in anti-CD20-treated multiple sclerosis patients

Objective

To examine humoral and cellular response in multiple sclerosis patients on anti-CD20 therapy after third BNT162b2 mRNA SARS-CoV-2 vaccination.

Methods

A prospective longitudinal study design from first throughout third vaccination in Danish and American MS centers. All participants were treated with ocrelizumab. Antibody (Ab) levels were assessed before and after third vaccination using SARS-CoV-2 IgG II Quant assay (Abbott Laboratories). B- and T-lymphocytes enumeration was done with BD Multitest™6-color TBNK reagent. Spike-specific T-cell responses were measured through PBMC stimulation with spike peptide pools (JPT Peptide Technologies).

Results

We found that 14.0%, 37.7%, and 33.3% were seropositive after first, second and third vaccination.

The median Ab-levels were 74.2 BAU/mL (range: 8.5–2427) after second vaccination, as well as 43.7 BAU/ml (range: 7.8–366.1) and 31.3 BAU/mL (range: 7.9–507.0) before and after third vaccination, respectively.

No difference was found in levels after second and third vaccination (p = 0.1475). Seropositivity dropped to 25.0% of participants before the third vaccination, a relative reduction of 33.3% (p = 0.0020). No difference was found between frequencies of spike reactive CD4⁺and CD8⁺ T-cells after second (0.65 ± 0.08% and 0.95 ± 0.20%, respectively) and third vaccination (0.99 ± 0.22% and 1.3 ± 0.34%, respectively).

Conclusion

In this longitudinal cohort we found no significant increased humoral or cellular response with administration of a third SARS-CoV-2 mRNA vaccination. These findings suggest the need for clinical strategies to include allowance of B cell reconstitution before repeat vaccination and/or provision of pre-exposure prophylactic monoclonal antibodies.