Rituximab in the treatment of pemphigus vulgaris

Comparison of the Clinical Efficacy of Rituximab Infusion and Dexamethasone-Cyclophosphamide Pulse Therapy and Their Effect on Serum Th1, Th2, and Th17 Cytokines in Pemphigus Vulgaris-A Prospective, Nonrandomized, Comparative Pilot Study

Background

Rituximab infusion and dexamethasone-cyclophosphamide pulse (DCP) are the two most popular regimens used in pemphigus vulgaris (PV) in India.

Objective

The present study compared the clinical efficacy of rituximab and DCP in Indian PV patients and their effects on serum Th1,2, and 17 cytokine levels.

Materials and Methods

A total of 37 patients received DCP (Group A, n = 22) or rituximab (Group B, rheumatoid arthritis protocol (n = 15)) as per patients' preference. They were monitored for clinical response, adverse events (AEs), changes in serum anti-desmoglein-1,3 antibody titers and Th1,2 and 17 cytokine levels at baseline and weeks 20 and 52.

Results

The proportion of patients attaining disease control, remission, and relapse in groups A and B were 82% and 93%; 73% and 93%; and 27% and 50%, respectively, after a median duration of 2 months each for disease control; 4 and 4.5 months for remission; and 5 and 7 months for relapse post remission. The musculoskeletal AEs were the highest in the two groups. Significant and comparable decreases in anti-dsg1 and 3 titers from baseline to weeks 20 and 52 were observed in both groups. Th1 and Th17 cytokine levels decreased, while Th2 cytokines increased post-treatment in both groups. However, no correlation was found between change in body surface area of involvement by PV and anti-dsg titers and cytokine levels before and after therapy in both groups.

Conclusion

Comparable clinical efficacy between DCP and rituximab was observed.

A Comprehensive Review on the Efficacy of Anti-CD20 Therapies in Pemphigus Treatment

Pemphigus, an autoimmune blistering disorder, poses significant therapeutic challenges due to dysregulated B cells and the involvement of CD20. This review assesses the efficacy of anti-CD20 therapies, including rituximab, ofatumumab, ocrelizumab, and obinutuzumab, in pemphigus treatment. Mechanisms of action, clinical studies, and safety profiles were analyzed, revealing diverse impacts on disease severity. B cell depletion emerged as a pivotal factor, disrupting the autoimmune process and reducing pathogenic antibodies. Varied efficacy and safety profiles among agents underscore the need for personalized treatment strategies guided by biomarkers. Challenges such as resistance and long-term safety concerns necessitate continued research and vigilance. In clinical practice, insights from this review inform nuanced, tailored approaches for improved pemphigus management. The dynamic landscape of emerging therapies and personalized medicine emphasizes the need for ongoing research and strategic clinical decision-making. This review is a foundation for future investigations, providing insights for clinicians and researchers in optimizing pemphigus treatment.

Rituximab in Pemphigus Vulgaris: A Review of Monoclonal Antibody Therapy in Dermatology

Pemphigus vulgaris (PV) is a rare autoimmune blistering disorder that primarily affects the skin and mucous membranes. Conventional treatments for PV, such as corticosteroids and immunosuppressive agents, have limitations in terms of efficacy and long-term safety. Monoclonal antibody therapy, specifically rituximab, has emerged as a promising therapeutic approach in the management of PV. This review article provides a comprehensive overview of rituximab in the treatment of PV, with a focus on its efficacy, safety profile, and immunological mechanisms of action. The article begins with an introduction to PV and the significance of monoclonal antibody therapy in dermatology. It then explores the clinical presentation and underlying immune-mediated mechanisms of PV, highlighting the autoimmune nature of the disease. The rationale for using monoclonal antibody therapy, particularly rituximab, in PV is discussed, emphasizing the limitations of conventional treatments and the concept of targeted therapy. The review delves into the efficacy and safety of rituximab based on clinical studies, evaluating disease remission rates, duration, and relapse rates. Furthermore, the immunological effects of rituximab, including B-cell depletion and modulation of the immune response, are explored in detail. Comparisons between rituximab and conventional treatment modalities in PV are made, assessing clinical outcomes, safety profiles, and long-term efficacy. Challenges and considerations in rituximab therapy are discussed, including factors influencing its efficacy, optimal dosing, treatment duration, and the need for maintenance therapy.

Early rituximab treatment is associated with increased and sustained remission in pemphigus patients: a retrospective cohort of 99 patients

OBJECTIVES

Rituximab is the front-line therapy for pemphigus disease. Although very effective, relapse rates are high. We assessed factors associated with disease remission and early relapse following the first rituximab cycle.

MATERIAL AND METHODS

A single center, retrospective cohort study of patients with pemphigus treated with rituximab (1000 mg days 0,14) at the Autoimmune Bullous Disease Clinic of the Division of Dermatology in Rabin Medical Center, Israel, between January 1, 1995 and March 31, 2020.

RESULTS

The cohort included 99 patients with a median follow-up of 37 months (range 12-155). After a single rituximab cycle, 74 patients (75%) achieved remission. Increased time to rituximab was associated with decreased remission rates (OR, 0.98 per month; 95%CI, 0.97-0.998). Of patients in remission with sufficient follow-up, 15/69 (22%) experienced an early relapse (≤12 months from remission). Prolonged time to rituximab and increased baseline disease severity, were associated with early relapse (OR, 1.02 per month; 95%CI, 1.001-1.04; OR, 1.04 per point; 95%CI, 1.01-1.08, accordingly).

CONCLUSIONS

Initiating rituximab early following diagnosis is recommended. Maintenance rituximab infusions, especially for patients with severe baseline disease, should be further investigated.

Real world evidence: Patients with refractory pemphigus treated with Rituximab

BACKGROUND

Pemphigus is a group of autoimmune blistering diseases, potentially life-threatening. Rituximab received FDA approval in June 2018 for the treatment of moderate to severe pemphigus vulgaris.

OBJECTIVES

To evaluate the efficacy and safety of rituximab in patients with pemphigus, resistant to previous therapies or unable to receive classic immunosuppressive treatment due to serious adverse events or comorbidities.

MATERIALS AND METHODS

Twenty-five patients (9 men, 16 women), mean age 49.4 ± 15.9 years (range 21-74 years), mean disease duration 4 ± 2.7 years (range 0.25-10 years) were included in the study: 19 patients with pemphigus vulgaris and 6 with pemphigus foliaceous. The efficacy of rituximab was evaluated according to the control of disease, retention of remission, disease severity, previous treatments and adverse reactions. During COVID-19 pandemic patients are monitored closely through tele-dermatology.

RESULTS

Twenty-three out of 25 patients had great improvement, 2 out of 25 ceased therapy due to adverse events (arthralgias and dyspnea). Sixteen out of 23 received additional course after 8 months (range 5-60 months). More aged patients presented more frequently adverse events and underwent additional courses (p = 0.002). Rituximab was found superior to classic immunosuppressive treatment in terms of efficacy and safety, with larger periods of remission and lower doses of corticosteroids and immunosuppressants. No major adverse events were noticed.

CONCLUSIONS

Rituximab is a very effective treatment of pemphigus and, remarkably, superior to classic immunosuppressive treatment.

The evolving role of rituximab in the treatment of pemphigus vulgaris: a comprehensive state-of-the-art review

INTRODUCTION

Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease. Systemic corticosteroids (CS), while life-saving, have several serious side effects. To improve treatment and prognosis, recently rituximab (RTX), a chimeric monoclonal antibody against CD20 molecule on B cells, has become popular. This Expert Opinion discusses clinical and scientifically relevant aspects of RTX treating PV.

AREA COVERED

This presentation describes the mechanism of action, clinical efficacy, safety, adverse events, protocols used, and clinical outcomes. Concerns for infection, reactivation of latent or previous infections, and high relapse rate are discussed.

EXPERT OPINION

Use of RTX in PV is still a work in progress. There are many unanswered questions. FDA did not provide a protocol or guidelines. Whenever RTX is used, systemic corticosteroids are simultaneously used, albeit for a shorter duration and lower dose. Used in these doses for these durations they can cause immunosuppression. Would it be more appropriate if instead of 'First Line Therapy' it would be more advisable to use the term 'First Adjunctive Immunosuppressive Agent'?

Rituximab in practice: Clinical evaluation of patients with pemphigus after rituximab administration

Pemphigus Vulgaris (PV) is a rare autoimmune blistering disease, which mainly causes mucosal and/or cutaneous lesions. In June 2018, FDA approved Rituximab (RTX)-a B-cell depleting agent-for the management of patients with moderate-to-severe pemphigus. Although the majority of patients respond well to this drug, some do not reach complete remission with a single cycle of RTX. In this review, following an overview of RTX and its clinical outcomes, we have focused on the possible outcomes after RTX therapy in patients with PV. The response is defined into four main categories; complete responders, partial responders, nonresponders, and paradoxical reactions, based on three possibilities of reaching the consolidation phase after 3 months, reaching remission until 6 months, and the ability of corticosteroid tapering in 6 months after RTX administration. Concerning the safety of RTX, three categories of infusion reactions, short and long-term side effects are discussed. Additionally, we have suggested approaches for the evaluation of clinical and serological responses at different critical time-points, including 1, 2, 3, and 6 months after RTX administration. Finally, available markers to predict the response to RTX and research gaps in the field of RTX therapy have been summarized.

Modified Rheumatoid Arthritis Protocol for Rituximab in Pemphigus: A Retrospective Case Series

Background: Rituximab, an anticluster of differentation 20 antibody, has been shown in open series studies to be effective in treating pemphigus. In the literature, lymphoma (dose of 375mg/m², four-week infusion) and rheumatoid arthritis (two infusions of 1,000mg each, 15 days apart) are two protocols extensively used for rituximab treatment in pemphigus. Objective: We investigated whether a modified rheumatoid arthritis protocol, in which the patient received a single treatment course ranging from 2 to 5 infusions of 1,000mg of rituximab during an interval of four weeks is safe and effective in pemphigus management. Methods: Patients with pemphigus were treated with a single treatment course ranging from 2 to 5 infusions of 1,000mg of rituximab during an interval of four weeks. Clinical consensus late endpoints and desmoglein 1 and desmoglein 3 indices were monitored. Results: We enrolled 32 patients in the study: four with pemphigus foliaceus (PF) and 28 with pemphigus vulgaris (PV). The follow-up period was 98.22±20.65 weeks (range: 40-140 weeks). All 32 patients responded to therapy. Nineteen patients achieved complete remission during a median period of 46 weeks (8 on minimal therapy, 11 off therapy). Thirteen patients achieved partial remission during a median period of 46 weeks (8 on minimal therapy, 5 off therapy). Relapses were seen in five (15.63%) patients between 72 and 96 weeks (median: 96 weeks) after the start of therapy. The antidesmoglein index correlated well with clinical improvement in PV or PF. Conclusion: Modified rheumatic arthritis protocol for rituximab was shown to be effective and safe in treating patients with pemphigus.

[Use of rituximab in maintenance treatment of pemphigus: A retrospective series]

INTRODUCTION

Rituximab (RTX), currently recommended as first-line treatment in moderate to severe pemphigus vulgaris (PV) and superficial pemphigus (PS) along with initial systemic steroids, may also be used as second-line or subsequent treatment, and this therapeutic strategy was investigated in a real-life monocentre retrospective survey.

MATERIAL AND METHODS

All patients treated between January 2010 and March 2018 with RTX as second-line or subsequent treatment for moderate to severe PV or PS and followed for at least one year were included. The main objective was to evaluate rates and times of complete clinical remission (CCR) after a first course of RTX. The secondary objectives consisted mainly of treatment safety, and frequency and time to relapse after the initial CCR.

RESULTS

The 24 patients selected received on average 2 cycles of RTX (i.e. 24 initial cycles and 24 additional cycles in all) over a mean follow-up period of 45 months. 18/24 (75%) patients achieved initial CCR within a mean 7.7 months. Despite at least one relapse in 13/18 initially responding patients regardless of relapse time, 59% (14/24) and 33% (8/24) were either in CCR and off treatment, or in partial remission, whether treated or untreated, according to the latest patient news, with an overall response rate of 92%. Safety was fair in these fragile patients.

DISCUSSION AND CONCLUSION

This survey of the practical use of RTX confirms its interest in moderate to severe pemphigus as a second-line or subsequent treatment, a situation that probably remains relevant even if this molecule is increasingly used as first-line therapy.

Post-rituximab immunoglobulin M (IgM) hypogammaglobulinemia

Rituximab is a B cell depleting monoclonal antibody that targets the B cell-specific cell surface antigen CD20 and is currently used to treat several autoimmune diseases. The elimination of mature CD20-positive B lymphocytes committed to differentiate into autoantibody-producing plasma cells is considered to be the major effect of rituximab, that makes it a beneficial biological agent in treating autoimmune diseases. Hypogammaglobulinemia has been reported after rituximab therapy in patients with lymphoma and rheumatoid arthritis. Similar data are scarce for other autoimmune diseases. Low immunoglobulin G (IgG) or hypogammaglobulinemia has attracted the most attention because of its significant role in protective immunity. However, the incidence and clinical implications of low immunoglobulin M (IgM) or hypogammaglobulinemia have not been studied in detail. This review will focus on the frequency and the clinical concerns of low IgM levels that result as a consequence of the administration of rituximab. The etiopathogenic mechanisms underlying post-rituximab IgM hypogammaglobulinemia and its implications are presented. The long-term consequences, if any, are not known or documented. Multiple factors may be involved in whether IgG or IgM decreases secondary to rituximab therapy. It is possible that the autoimmune disease itself may be one of the important factors. The dose, frequency and number of infusions appear to be important variables. Post-rituximab therapy immunoglobulin levels return to normal. During this process. IgM levels take a longer time to return to normal levels when compared to IgG or other immunoglobulins. IgM deficiency persists after B cell repopulation to normal levels has occurred. Laboratory animals and humans deficient in IgM can have multiple infections. Specific pharmacologic agents or biologic therapy that address and resolve IgM deficiency are currently unavailable. If the clinical situation so warrants, then prophylactic antibiotics may be indicated and perhaps helpful. Research in this iatrogenic phenomenon will provide a better understanding of not only the biology of IgM, but also the factor(s) that control its production and regulation, besides its influence if any, on rituximab therapy.

Updates on diagnosis and management of autoimmune blistering diseases

Over the last several decades, advances in the understanding of the pathogenesis of autoimmune blistering diseases has resulted in significant improvements in diagnosis and management. These improvements include new diagnostic assays and therapies targeted at specific disease mediators. Furthermore, the abundance of new therapies in clinic trials for autoimmune blistering diseases will translate to an enhanced therapeutic armamentarium for clinicians. The aim of this article is to review new developments in the understanding of autoimmune blistering diseases and to summarize advancements in their diagnosis and management.

Pemphigus and mucous membrane pemphigoid: An update from diagnosis to therapy

Pemphigus diseases (PDs) and mucous membrane pemphigoid (MMP) are a group of immune-mediated mucocutaneous disorders clinically characterized by the formation of blisters, erosions and ulcers. The skin and mucous membranes are predominantly affected, with the oropharyngeal mucosa as the initially involved site. Ocular involvement is also a frequent feature of these diseases. Because of the considerable overlap in their clinical presentations, the diagnosis of PDs vs. MMP can be challenging. A recognition of their specific immunological and histopathologic features is crucial in the differential diagnosis. Treatment modalities include systemically administered corticosteroids, steroid-sparing immunosuppressive agents, and biologic therapies (rituximab, intravenous immunoglobulins, and anti-tumor necrosis factor agents). Topical, oral, conjunctival, or intralesional corticosteroids as well as anti-inflammatory drugs and antibiotics are prescribed as needed.

Emerging treatment options for the management of pemphigus vulgaris

Pemphigus vulgaris (PV) is a life-threatening disease belonging to the pemphigus group of autoimmune intra-epidermal bullous diseases of the skin and mucosae. The therapeutic management of PV remains challenging and, in some cases, conventional therapy is not adequate to induce clinical remission. The cornerstone of PV treatment remains systemic corticosteroids. Although very effective, long-term corticosteroid administration is characterized by substantial adverse effects. Corticosteroid-sparing adjuvant therapies have been employed in the treatment of PV, aiming to reduce the necessary cumulative dose of corticosteroids. Specifically, immunosuppressive agents such as azathioprine and mycophenolate mofetil are widely used in PV. More recently, high-dose intravenous immunoglobulins, immunoadsorption, and rituximab have been established as additional successful therapeutic options. This review covers both conventional and emerging therapies in PV. In addition, it sheds light on potential future treatment strategies for this disease.

Pemphigus trigger factors: special focus on pemphigus vulgaris and pemphigus foliaceus

Pemphigus is a general term for a rare group of autoimmune diseases which result in the formation of blisters on the skin and oral cavity. Although there is no way to prevent autoimmune diseases, some factors may trigger pemphigus initiation in susceptible individuals or be exacerbated in affected patients. Recognition of these triggers, based on the latest studies and experiences is essential and should be updated every few years. In this study, several triggers, including different drugs and treatments, diseases, vaccines, genetic factors, nutrients, micronutrients, pregnancy, stress, and various other triggers have been discussed. Some possible triggers, such as blood antigens and the effect of seasons have also been discussed briefly. Moreover, some protective factors against pemphigus have been reviewed. Considering the molecular mechanism of pemphigus and immune response alteration during this disease, some possible triggers have been suggested and discussed. Although those triggers may be a real threat, more studies are needed to support these hypotheses.

Shifting Focus in the Therapeutics of Immunobullous Disease

Therapeutics of autoimmune bullous disease has seen a major shift of focus from more global immunosuppression to targeted immunotherapy. Anti CD 20 monoclonal antibody Rituximab revolutionized the therapeutics of autoimmune bullous disease particularly pemphigus. Though it is still being practiced off-label, evidences in the form of RCT and meta analysis are now available. Other novel anti CD 20 monoclonal antibodies like ofatumumab, veltuzumab, and ocrelizumab, tositumomab or obinutuzumab/GA101 may add to the therapeutic options in coming days. Beyond anti CD 20 monoclonal antibodies other options that show promise at least in select scenario are omalizumab, TNF inhibitors plasmapheresis and intravenous immunoglobulin. The present article will discuss the role of rituximab and other newer therapeutics in the treatment of autoimmune blistering disease, especially pemphigus and suggests their positions in the therapeutic ladder.

Management of pemphigus vulgaris: challenges and solutions

The main objective in the treatment of pemphigus vulgaris is to control the disease, prevent relapses, and avoid adverse events associated with the prolonged use of steroids and immunosuppressive agents. Systemic corticosteroids remain the gold standard treatment for pemphigus vulgaris. Azathioprine and mycophenolate mofetil are the first line of steroid-sparing treatment. Rituximab is extremely effective in recalcitrant pemphigus, when other treatments fail to control the disease. The European Dermatology Forum recommends tapering prednisolone by 25% every 2 weeks after the consolidation phase, and a 5 mg reduction every 4 weeks when the dose is reduced to <20 mg. If the patient relapses, options include increasing steroids back to the previous dose, adding an immunosuppressant if using steroid monotherapy, or replacing a first-line immunosuppressant by another if already on combination therapy.

Cost and Resource Use of Pemphigus and Pemphigoid Disorders Pre- and Post-Rituximab

Background

Rituximab (RTX) is increasingly used for the treatment of pemphigus and pemphigoid disorders. The high cost of RTX frequently limits its use and access.

Objective

To determine the health system resources and costs associated with RTX treatment of pemphigus and pemphigoid.

Methods

Health system resources and costs attributed to a convenience sample of 89 patients with either pemphigus or pemphigoid were identified, quantified, and valued 6 months prior to and following RTX initiation between May 2006 and August 2012. Overall cohort costs and costs per patient were calculated (2013 Can$).

Results

The overall cohort cost for 6 months pre-RTX was $3.8 million and for 6 months post-RTX was $2.6 million. The average cost per patient decreased from $42,231 to $29,423 (30.3% decrease). The main cost driver was intravenous immunoglobulin.

Conclusions

Our findings suggest that RTX is effective in reducing health system resources and the costs associated with the treatment of pemphigus and pemphigoid.

Immune-mediated diseases: what can be found in the oral cavity?

Immune-mediated diseases frequently affect oral mucosa, which may often be the first site of clinical manifestation. In this review, we describe the most important oral lesions related to inflammatory disorders and present their management and novel therapies. The review is based on an open PubMed literature search from 1980 to 2012 with relevant keywords. Pemphigus vulgaris, oral lichen planus, cicatricial pemphigoid, erythema multiforme, Stevens-Johnson syndrome, systemic lupus erythematosus, Sjögren's syndrome, and linear IgA dermatosis are the immune-mediated diseases with oral manifestations discussed. Etiology is unknown in most of these diseases, but recently some of them have been found to share common genes. Modern treatment of these diseases is based on drugs that interfere along the pathogenic mechanisms instead of the still commonly used palliative measures. However, the immunomodulatory drugs may also cause oral side effects, complicating the clinical picture. Therefore, consulting dental or oral medicine specialists can be necessary in some cases with various immune-mediated diseases.

Biologics in dermatology: an integrated review

The advent of biologics in dermatologic treatment armentarium has added refreshing dimensions, for it is a major breakthrough. Several agents are now available for use. It is therefore imperative to succinctly comprehend their pharmacokinetics for their apt use. A concerted endeavor has been made to delve on this subject. The major groups of biologics have been covered and include: Drugs acting against TNF-α, Alefacept, Ustekinumab, Rituximab, IVIG and Omalizumab. The relevant pharmacokinetic characteristics have been detailed. Their respective label (approved) and off-label (unapproved) indications have been defined, highlighting their dosage protocol, availability and mode of administration. The evidence level of each indication has also been discussed to apprise the clinician of their current and prospective uses. Individual anti-TNF drugs are not identical in their actions and often one is superior to the other in a particular disease. Hence, the section on anti-TNF agents mentions the literature on each drug separately, and not as a group. The limitations for their use have also been clearly brought out.

Rituximab

Rituximab (Rituxan^®, MabThera^®, and Genentech/Roche) is a chimeric murine/human monoclonal IgG1k antibody directed against the CD20 antigen located at the surface of normal and malignant B lymphocytes.

Plakophilin-1 protects keratinocytes from pemphigus vulgaris IgG by forming calcium-independent desmosomes

Plakophilin-1 (PKP-1) is an armadillo family protein critical for desmosomal adhesion and epidermal integrity. In the autoimmune skin-blistering disease pemphigus vulgaris (PV), autoantibodies (IgG) target the desmosomal cadherin desmoglein 3 (Dsg3) and compromise keratinocyte cell-cell adhesion. Here, we report that enhanced expression of PKP-1 protects keratinocytes from PV IgG-induced loss of cell-cell adhesion. PKP-1 prevents loss of Dsg3 and other desmosomal proteins from cell-cell borders and prevents alterations in desmosome ultrastructure in keratinocytes treated with PV IgG. Using a series of Dsg3 chimeras and deletion constructs, we find that PKP-1 clusters Dsg3 with the desmosomal plaque protein desmoplakin in a manner dependent on the plakoglobin-binding domain of the Dsg3 tail. Furthermore, PKP-1 expression transforms desmosome adhesion from a calcium-dependent to a calcium-independent and hyperadhesive state. These results demonstrate that manipulating the expression of a single desmosomal plaque protein can block the pathogenic effects of PV IgG on keratinocyte adhesion.

p38 MAPK Signaling in Pemphigus: Implications for Skin Autoimmunity

p38 mitogen activated protein kinase (p38 MAPK) signaling plays a major role in the modulation of immune-mediated inflammatory responses and therefore has been linked with several autoimmune diseases. The extent of the involvement of p38 MAPK in the pathogenesis of autoimmune blistering diseases has started to emerge, but whether it pays a critical role is a matter of debate. The activity of p38 MAPK has been studied in great detail during the loss of keratinocyte cell-cell adhesions and the development of pemphigus vulgaris (PV) and pemphigus foliaceus (PF). These diseases are characterised by autoantibodies targeting desmogleins (Dsg). Whether autoantibody-antigen interactions can trigger signaling pathways (such as p38 MAPK) that are tightly linked to the secretion of inflammatory mediators which may perpetuate inflammation and tissue damage in pemphigus remains unclear. Yet, the ability of p38 MAPK inhibitors to block activation of the proapoptotic proteinase caspase-3 suggests that the induction of apoptosis may be a consequence of p38 MAPK activation during acantholysis in PV. This review discusses the current evidence for the role of p38 MAPK in the pathogenesis of pemphigus. We will also present data relating to the targeting of these cascades as a means of therapeutic intervention.