Mitigating alemtuzumab-associated autoimmunity in MS: A "whack-a-mole" B-cell depletion strategy

Impact of High-Efficacy Therapies for Multiple Sclerosis on B Cells

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative autoimmune disorder of the central nervous system characterized by demyelination and neurodegeneration. Traditionally considered a T-cell-mediated disease, the crucial role of B lymphocytes in its pathogenesis, through different mechanisms contributing to inflammation and autoreactivity, is increasingly recognized. The risk of long-term disability in MS patients can be reduced by an early treatment initiation, in particular with high-efficacy therapies. The aim of this review is to provide an overview of the mechanisms of action of high-efficacy therapies for MS, with a focus on their impact on B cells and how this contributes to the drugs' efficacy and safety profiles. Anti-CD20 monoclonal antibodies, Alemtuzumab, Cladribine and sequestering therapies encompassing Natalizumab and S1P receptors modulators will be discussed and emerging therapies, including Bruton's Tyrosine Kinase inhibitors, will be presented.

Alemtuzumab and thrombotic thrombocytopenic purpura: Analysis of an international surveillance database and systematic literature review

OBJECTIVES

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy associated with severe deficiency in ADAMTS13. ADAMTS13 deficiency may be secondary to absent or dysfunctional protein production due to mutations in the ADAMTS13 gene (congenital TTP) or autoantibody-mediated clearance and/or inhibition (immune-mediated TTP). This autoimmunity may, albeit rarely, occur secondary to certain medications (eg, ticlopidine). Recent case reports have implicated alemtuzumab (LETRADA), a monoclonal antibody that selectively inhibits CD52, as a cause of secondary TTP. We aimed to characterize all reports of TTP potentially associated with alemtuzumab.

METHODS

We performed a cross-sectional analysis of the United States Food and Drug Administration's Adverse Event Reporting System (FAERS) database as of 21 November 2024 and systematically reviewed the literature as of 03 September 2024 for all reported cases of secondary TTP potentially associated with alemtuzumab. Patient demographics, therapy indications, associated medications, and outcomes were abstracted.

RESULTS

We identified 49 reports of TTP possibly related to alemtuzumab administration since 01 January 2001 in the FAERS database, 9 of which resulted in death. Most patients (n = 31) were receiving alemtuzumab for multiple sclerosis (MS), while 8 reports were in patients undergoing hematopoietic stem cell transplantation. We identified two additional cases in the literature review in patients receiving alemtuzumab for MS.

CONCLUSIONS

In conjunction with studies of the United Kingdom's and European Union's pharmacovigilance databases, these results support the current package insert for alemtuzumab in which TTP is listed as a "warning and precaution". Increased awareness of this possible side effect, and prolonged monitoring, is warranted.

Autologous haematopoietic stem cell transplantation for treatment of multiple sclerosis and neuromyelitis optica spectrum disorder - recommendations from ECTRIMS and the EBMT

Autologous haematopoietic stem cell transplantation (AHSCT) is a treatment option for relapsing forms of multiple sclerosis (MS) that are refractory to disease-modifying therapy (DMT). AHSCT after failure of high-efficacy DMT in aggressive forms of relapsing-remitting MS is a generally accepted indication, yet the optimal placement of this approach in the treatment sequence is not universally agreed upon. Uncertainties also remain with respect to other indications, such as in rapidly evolving, severe, treatment-naive MS, progressive MS, and neuromyelitis optica spectrum disorder (NMOSD). Furthermore, treatment and monitoring protocols, rehabilitation and other supportive care before and after AHSCT need to be optimized. To address these issues, we convened a European Committee for Treatment and Research in Multiple Sclerosis Focused Workshop in partnership with the European Society for Blood and Marrow Transplantation Autoimmune Diseases Working Party, in which evidence and key questions were presented and discussed by experts in these diseases and in AHSCT. Based on the workshop output and subsequent written interactions, this Consensus Statement provides practical guidance and recommendations on the use of AHSCT in MS and NMOSD. Recommendations are based on the available evidence, or on consensus when evidence was insufficient. We summarize the key evidence, report the final recommendations, and identify areas for further research.

The role of alemtuzumab in the development of secondary autoimmunity in multiple Sclerosis: a systematic review

BACKGROUND

Secondary autoimmune disease (SAID) in the context of alemtuzumab treatment is one of the main safety concerns that may arise following administration in people with multiple sclerosis (pwMS). Contributing factors underlying this adverse event are not well understood. The purpose of this systematic review was to appraise the literature investigating the role of alemtuzumab in the development of SAID in pwMS following treatment and identify potential biomarkers/ risk factors that may be predictive of onset of this manifestation.

METHODS

Relevant publications were retrieved from PubMed, Embase, and Web of Science using a three-pronged search strategy containing the following keywords: "multiple sclerosis"; "alemtuzumab"; and "autoimmunity". Studies that fulfilled the specified eligibility criteria and investigated SAID development after alemtuzumab in pwMS were included in the final analysis.

RESULTS

19 papers were included in the final review. Approximately, 47.92% of pwMS treated with alemtuzumab experienced SAID. A variety of biomarkers and risk factors were noted in the development of SAID, with a focus on immunological changes, including: increased homeostatic proliferation and T cell cycling, along with consistently elevated baseline serum IL-21 levels and thyroid autoantibodies. There was no significant association between known human leukocyte antigen (HLA) risk alleles, lymphocyte profile or dynamics and SAID development.

CONCLUSIONS

While the mechanism underlying SAID following alemtuzumab is not fully understood, potential biomarkers and risk factors that may assist in elucidating mechanisms underlying this phenomenon have been documented in several independent studies. Following immunodepletion from alemtuzumab, an IL-21 driven increase in homeostatic proliferation and T cell cycling may disrupt tolerance mechanisms leading to an increase in the propensity toward alemtuzumab-induced autoimmunity. Further research is necessary to clarify the physiological changes after alemtuzumab therapy that trigger SAID in pwMS.

Ocrelizumab in MS patients with persistence of disease activity after alemtuzumab: A multi-center Italian study

BACKGROUND

The reason why some multiple sclerosis (MS) patients show disease activity after alemtuzumab (ALM) is still unclear, but ocrelizumab (OCR) could represent an interesting sequential therapeutic approach.

OBJECTIVES

To investigate safety and efficacy of OCR in MS patients with disease activity after two ALM courses.

METHODS

Observational retrospective multi-centers Italian cohort study.

RESULTS

Seventy-two subjects were included. Mean follow-up (FU) was 2.4 (±1) years. Forty-five patients (62.5%) experienced at least one adverse event (AE), with infections accounting for 96.7% of cases. A reduction in total lymphocytes was observed between OCR start and 6 months FU, driven by BCD19+ lymphocytes depletion (p < 0.001). Immunoglobulin M (IgM) levels decreased between OCR start and 6 months FU (p < 0.001). At 2-year FU, relapse, magnetic resonance imaging (MRI) activity and disability worsening-free survival were 92.1%, 90.8%, and 89.2%. The evidence of inflammatory activity between the two ALM courses was associated with higher risk of relapse, MRI activity, and NEDA-3 status loss in relapsing-remitting multiple sclerosis (RRMS; p = 0.02, p = 0.05, p = 0.01, respectively).

CONCLUSIONS

OCR after two ALM courses seemed to be safe and effective. Early IgM hypogammaglobulinemia occurred in a high proportion of patients. The evidence of inflammatory activity between ALM courses seemed to increase the risk of MS re-activation on OCR treatment.

Thyroid autoimmunity following alemtuzumab treatment in multiple sclerosis patients: a prospective study

Autoimmune thyroid disease (AITD) is the most common adverse effect in alemtuzumab (ALZ) treated relapsing-remitting (RR) multiple sclerosis (MS) patients. The objective of this prospective study was to analyze the occurrence, timing of onset, clinical course, and laboratory characteristics of AITD post-ALZ. We evaluated 35 RRMS patients treated with ALZ at a single academic MS center; clinical and laboratory data were collected before ALZ initiation and thereafter quarterly on follow-up with a median of 43.5 months. Seventeen out of 31 patients (54.8%) with no prior history of thyroid dysfunction developed AITD with a mean onset of 19.4 months ± 10.2 (SD) after the first ALZ cycle; Graves' disease (GD) (n = 9); hypothyroidism with positive stimulating thyrotropin receptor antibodies (TRAb) (n = 1); Hashimoto thyroiditis (HT) (n = 6); HT with hypothyroidism (n = 1). Interestingly, seven of nine (77.7%) GD patients showed a fluctuating course. Three out of four patients with preexisting thyroid disease remained stable, whereas one with prior HT and hypothyroidism developed fluctuating GD. All patients with GD commenced antithyroid drugs (ATDs); five continued on "block and replace" treatment; one required radioactive iodine, and one total thyroidectomy. Our analysis showed earlier onset of ALZ-induced AITD in comparison to most other ALZ cohorts; overall, these patients required complex therapeutic approaches of the AITD. We observed a higher rate of fluctuating GD, with earlier onset and lower remission rate than previously reported, which in the majority of patients required prolonged "block and replace" therapy in the minimum dose of each therapeutic agent or more definitive interventions.

Alemtuzumab-Related Lymphocyte Subset Dynamics and Disease Activity or Autoimmune Adverse Events: Real-World Evidence

BACKGROUND AND OBJECTIVES

alemtuzumab is a monoclonal anti-CD52 antibody acting on B and T cells in highly active multiple sclerosis (MS). We analyzed changes in lymphocyte subsets after alemtuzumab administration in relation to disease activity and autoimmune adverse events.

METHODS

lymphocyte subset counts were assessed longitudinally using linear mixed models. Subset counts at baseline and during follow-up were correlated with relapse rate, adverse events, or magnetic resonance (MRI) activity.

RESULTS

we recruited 150 patients followed for a median of 2.7 years (IQR: 1.9-3.7). Total lymphocytes, CD4, CD8, and CD20 significantly decreased in all patients over 2 years (p < 0.001). Previous treatment with fingolimod increased the risk of disease activity and adverse events (p = 0.029). We found a higher probability of disease reactivation in males and in patients with over three active lesions at baseline. Higher EDSS scores at baseline and longer disease duration predicted the switch to other treatments after alemtuzumab.

DISCUSSION AND CONCLUSIONS

Our real-world study supports data from clinical trials in which lymphocyte subsets were not useful for predicting disease activity or autoimmune disease during treatment. The early use of an induction therapy such as alemtuzumab in patients with a lower EDSS score and short history of disease could mitigate the risk of treatment failure.

Changes in John Cunningham Virus Index in Multiple Sclerosis Patients Treated with Different Disease-Modifying Therapies

BACKGROUND

Progressive Multifocal Leukoencephalopathy (PML) is an opportunistic infection caused by John Cunningham virus (JCV) reactivation, potentially associated with natalizumab (NTZ) treatment for Multiple Sclerosis (MS). The anti-JCV antibodies titre (JCV index) increases during NTZ treatment; however, the effects of other disease-modifying therapies (DMTs) on the JCV index have not been fully explored.

OBJECTIVE

The aim of the study was to evaluate changes in the JCV index during treatment with several DMTs.

METHODS

This longitudinal study evaluated the JCV index before starting DMT (T0) and during treatment with DMT (T1).

RESULTS

A total of 260 participants (65.4 % females, mean age 43 ± 11.3 ) were enrolled: 68 (26.2 %) treated with fingolimod (FTY), 65 (25 %) rituximab or ocrelizumab (RTX/OCR), 37 (14.2 %) dimethyl-fumarate (DMF), 29 (11.2 %) cladribine (CLD), 23 (8.8 %) teriflunomide (TFM), 20 (7.7 %) interferon or glatiramer acetate (IFN/GA), and 18 (6.9 %) alemtuzumab (ALM). At T1, the percentage of patients with JCV index <0.90 was found to be significantly increased in the ALM group (16.7 % versus 66.7 %, p = 0.05), while the percentage of patients with JCV index >1.51 was found to be significantly reduced in the RTX/OCR group (51.6 % versus 37.5 %, p = 0.04). In the FTY group, a significant reduction in the percentage of patients with JCV index <0.90 was also found (23.5 % versus 1.4 %, p = 0.0006). The mean JCV index was reduced in the RTX/OCR and ALM groups, while a significant increase was observed in the FTY group.

CONCLUSION

DMTs with a T and/or B depleting mechanism of action induced a significant reduction in the JCV index. These results may suggest new possible sequencing strategies potentially maximizing disease control while reducing the PML risk.

Monoclonal Antibodies in the Treatment of Relapsing Multiple Sclerosis: an Overview with Emphasis on Pregnancy, Vaccination, and Risk Management

Monoclonal antibodies have become a mainstay in the treatment of patients with relapsing multiple sclerosis (RMS) and provide some benefit to patients with primary progressive MS. They are highly precise by specifically targeting molecules displayed on cells involved in distinct immune mechanisms of MS pathophysiology. They not only differ in the target antigen they recognize but also by the mode of action that generates their therapeutic effect. Natalizumab, an [Formula: see text]4[Formula: see text]1 integrin antagonist, works via binding to cell surface receptors, blocking the interaction with their ligands and, in that way, preventing the migration of leukocytes across the blood-brain barrier. On the other hand, the anti-CD52 monoclonal antibody alemtuzumab and the anti-CD20 monoclonal antibodies rituximab, ocrelizumab, ofatumumab, and ublituximab work via eliminating selected pathogenic cell populations. However, potential adverse effects may be serious and can necessitate treatment discontinuation. Most importantly, those are the risk for (opportunistic) infections, but also secondary autoimmune diseases or malignancies. Monoclonal antibodies also carry the risk of infusion/injection-related reactions, primarily in early phases of treatment. By careful patient selection and monitoring during therapy, the occurrence of these potentially serious adverse effects can be minimized. Monoclonal antibodies are characterized by a relatively long pharmacologic half-life and pharmacodynamic effects, which provides advantages such as permitting infrequent dosing, but also creates disadvantages regarding vaccination and family planning. This review presents an overview of currently available monoclonal antibodies for the treatment of RMS, including their mechanism of action, efficacy and safety profile. Furthermore, we provide practical recommendations for risk management, vaccination, and family planning.

MS: Rituximab verhindert sekundäre Autoimmunität nach Alemtuzumab- Therapie

Alemtuzumab ist ein monoklonaler Antikörper und zerstört maligne B- und T-Lymphozyten durch Bindung an das Glykoprotein CD52. Obgleich der Wirkstoff mit Erfolg zur Therapie der Multiplen Sklerose (MS) eingesetzt wird, zählt sekundäre Autoimmunität zu den häufigsten Nebenwirkungen. Meltzer und Team wollten wissen, ob eine Gabe niedrig dosiertem Rituximab diesen Nebeneffekt abmildern könnte, und präsentieren die Ergebnisse ihrer Pilotstudie.

OUP accepted manuscript

Alemtuzumab is a monoclonal antibody that causes rapid depletion of CD52-expressing immune cells. It has proven to be highly efficacious in active relapsing–remitting multiple sclerosis; however, the high risk of secondary autoimmune disorders has greatly complicated its use. Thus, deeper insight into the pathophysiology of secondary autoimmunity and potential biomarkers is urgently needed. The most critical time points in the decision-making process for alemtuzumab therapy are before or at Month 12, where the ability to identify secondary autoimmunity risk would be instrumental. Therefore, we investigated components of blood and CSF of up to 106 multiple sclerosis patients before and after alemtuzumab treatment focusing on those critical time points.

Consistent with previous reports, deep flow cytometric immune-cell profiling (n = 30) demonstrated major effects on adaptive rather than innate immunity, which favoured regulatory immune cell subsets within the repopulation. The longitudinally studied CSF compartment (n = 18) mainly mirrored the immunological effects observed in the periphery. Alemtuzumab-induced changes including increased numbers of naïve CD4⁺ T cells and B cells as well as a clonal renewal of CD4⁺ T- and B-cell repertoires were partly reminiscent of haematopoietic stem cell transplantation; in contrast, thymopoiesis was reduced and clonal renewal of T-cell repertoires after alemtuzumab was incomplete. Stratification for secondary autoimmunity did not show clear immununological cellular or proteomic traits or signatures associated with secondary autoimmunity. However, a restricted T-cell repertoire with hyperexpanded T-cell clones at baseline, which persisted and demonstrated further expansion at Month 12 by homeostatic proliferation, identified patients developing secondary autoimmune disorders (n = 7 without secondary autoimmunity versus n = 5 with secondary autoimmunity). Those processes were followed by an expansion of memory B-cell clones irrespective of persistence, which we detected shortly after the diagnosis of secondary autoimmune disease.

In conclusion, our data demonstrate that (i) peripheral immunological alterations following alemtuzumab are mirrored by longitudinal changes in the CSF; (ii) incomplete T-cell repertoire renewal and reduced thymopoiesis contribute to a proautoimmune state after alemtuzumab; (iii) proteomics and surface immunological phenotyping do not identify patients at risk for secondary autoimmune disorders; (iv) homeostatic proliferation with disparate dynamics of clonal T- and B-cell expansions are associated with secondary autoimmunity; and (v) hyperexpanded T-cell clones at baseline and Month 12 may be used as a biomarker for the risk of alemtuzumab-induced autoimmunity.

Using Monoclonal Antibody Therapies for Multiple Sclerosis: A Review

Monoclonal antibody therapies have secured an important role in the therapeutic landscape for the treatment of both relapsing and progressive forms of multiple sclerosis due to their potent efficacy, convenient dosing schedules, and well-defined side effect profiles. Each therapy has unique risks and benefits associated with its specific mechanism of action which ultimately guides clinical decision-making for individual patients. This review will summarize the mechanisms of action, evidence leading to their approval, and clinically relevant considerations for each of the current monoclonal antibody therapies approved for the treatment of multiple sclerosis.

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.

A real-world cohort analysis of alemtuzumab outcomes in relapsing multiple sclerosis

Multiple sclerosis (MS) is a chronic and progressive neurological disease characterized by recurrent episodes of inflammatory demyelination of the brain and spinal cord. Alemtuzumab has been previously shown in large phase III trials to be an effective therapy in reducing MS clinical flares as well as new radiological activity and atrophy rates. The purpose of this study was to examine real-world effectiveness and safety data from a large cohort of people treated with alemtuzumab at an academic medical center, including those who failed B-cell depletion therapy. Over an average of 2.6 years follow-up, there were small but significant improvements in neurological disability scores, and a 61% rate of the composite "No Evidence of Disease Activity" (NEDA-3) outcome at 2-year follow-up. There were no substantial safety issues encountered in our review; rates of adverse events were similar or below those reported in Phase III trials. We compare and contrast our results to other available real-world data using alemtuzumab in multiple sclerosis.