Treatment of Refractory Pemphigus with the Anti-CD20 Monoclonal Antibody (Rituximab)

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.

Current biologics in treatment of pemphigus foliaceus: a systematic review

Background

Pemphigus foliaceus (PF) differs from pemphigus vulgaris (PV) in that it affects only the skin and mucous membranes are not involved. Pemphigus is commonly treated with systemic corticosteroids and immunosuppressive agents (ISAs). More recently, biologics have been used. The current literature on biologic therapy often combines treatment of PF with PV, hence it is often difficult for clinicians to isolate the treatment of PF from PV. The purpose of this review was to provide information regarding the use of current biological therapy, specifically in PF.

Materials and methods

A search of PubMed, Embase, and other databases was conducted using keywords pemphigus foliaceus (PF), rituximab (RTX), intravenous immunoglobulin (IVIg), and biologics. Forty-one studies were included in this review, which produced 105 patients with PF, treated with RTX, IVIg, or a combination of both. Eighty-five patients were treated with RTX, eight patients with IVIg, and 12 received both RTX and IVIg.

Results

Most patients in this review had PF that was nonresponsive to conventional immunosuppressive therapies (CIST), and had significant side effects from their use. RTX treatment resulted in complete remission (CR) in 63.2%, a relapse rate of 39.5%, an infection rate of 19.7%, and a mortality rate of 3.9%. Relapse was greater in the lymphoma (LP) protocol than the rheumatoid arthritis (RA) protocol (p<0.0001). IVIg led to CR in 62.5% of patients, with no relapses or infections. Patients receiving both biologics experienced better outcomes when RTX was first administered, then followed by IVIg. Follow-up durations for patients receiving RTX, IVIg, and both were 22.1, 24.8, and 35.7 months, respectively.

Discussion

In pemphigus foliaceus patients nonresponsive to conventional immunosuppressive therapy or in those with significant side effects from CIST, RTX and IVIg appear to be useful agents. Profile of clinical response, as well as relapse, infection, and mortality rates in PF patients treated with RTX were similar to those observed in PV patients. The data suggests that protocols specific for PF may produce better outcomes, less adverse effects, and improved quality of life.

Pemphigus vulgaris with refractory gingival ulcerations, successfully treated with rituximab-A case report

A patient presented with ulcerations of the buccal mucosae, palate and gingiva. A gingival biopsy confirmed the diagnosis as pemphigus vulgaris. Despite medication with systemic corticosteroids and mycophenolate mofetil, desquamative gingivitis persisted. Adjunct treatment with rituximab was therefore introduced. Regular follow-ups revealed no inflammatory gingival changes even 6 years later.

Long-term experience with rituximab therapy for treatment-resistant moderate-to-severe pemphigus

BACKGROUND

Rituximab appears to be effective for treating pemphigus, although there are limited long-term data.

METHODS

This retrospective single-center study evaluated patients with conventional treatment-resistant pemphigus who received rituximab during September 2010-December 2019. The first rituximab cycle was based on the rheumatoid arthritis protocol in all patients except one patient, and additional single doses (500 mg or 1000 mg) were administered after clinical and/or serological relapse. The consensus definitions were used for complete remission off therapy, complete remission on minimal therapy, and clinical relapse. Serological relapse was defined as a progressive ≥2-fold increase in anti-desmoglein titers (vs. previous the measurement).

RESULTS

The study included 52 patients with pemphigus vulgaris and 1 patient with pemphigus foliaceus. The mean number of infusions was 5 and the average follow-up after the first infusion was 56 months. The average time to clinical and/or serological relapse was 12 months. Complete remission was achieved in 84.9% of patients, including after the first rituximab cycle in 25 patients (47.1%). Two patients died during the follow-up period.

CONCLUSION

Additional rituximab cycles may help achieve and prolong remission in patients with moderate-to-severe pemphigus resistant to conventional therapies. However, prospective trials are needed to identify the optimal dosing protocol.

B-cell targeted therapies in pemphigus

Pemphigus is a rare autoimmune disease of the skin, characterized by autoantibodies targeting adhesion proteins of the epidermis, in particular desmoglein 3 and desmoglein 1, that cause the loss of cell-cell adhesion and the formation of intraepidermal blisters. Given that these autoantibodies are both necessary and sufficient for pemphigus to occur, the goal of pemphigus therapy is the elimination of autoreactive B-cells responsible for autoantibody production. Rituximab, an anti-CD20 monoclonal antibody, was the first targeted B-cell therapy approved for use in pemphigus and is now considered the frontline therapy for new onset disease. One limitation of this treatment is that it targets both autoreactive and non -autoreactive B-cells, which accounts for the increased risk of serious infections in treated patients. In addition, most rituximab-treated patients experience disease relapse, highlighting the need of new therapeutic options. This review provides a concise overview of rituximab use in pemphigus and discusses new B-cell and antibody-directed therapies undergoing investigation in clinical studies.

New onset pemphigus foliaceus during pregnancy: A rare case

Pemphigus is a rare autoimmune disease during pregnancy. Among the different pemphigus types, pemphigus foliaceus (PF) is even rarer than pemphigus vulgaris. We present a case of PF in a 36-year-old female patient who presented with PF onset during pregnancy in the form of a disseminated, erythematosquamous rash. A diagnosis was made on the basis of histologic, immunofluorescence, and enzyme-linked immunosorbent assay results. A complete remission was recorded a month after steroid treatment initiation. The patient delivered a premature (33 weeks) but otherwise healthy baby girl. Only three cases of PF have been reported in two retrospective studies found in the English-language bibliography. Although pemphigus during pregnancy is a rare disease and treatment guidelines have not yet been elucidated, the management of these cases is individually evaluated. In all cases, the primary goal should be the control of the maternal disease along with the safety of the fetus.

Rituximab in pemphigus

Pemphigus is a severe autoimmune blistering disease mediated by pathogenic anti-desmoglein antibodies leading to an inter keratinocyte disjunction. Rituximab is a monoclonal antibody that binds to the CD-20 antigen of B lymphocytes, which causes B-cell depletion and a subsequent reduction in pathogenic autoantibodies. Its therapeutic role in pemphigus has been progressively growing with increasing evidence of successful outcomes. Rituximab was initially off-labeled used as an alternative in patients with recalcitrant or relapsing pemphigus and in patients with contraindications to systemic corticosteroids. Recently, a large randomized clinical trial has shown that first-line use of rituximab combined with short-term prednisone regimen was both more effective and potentially safer than a standard regimen of high doses of corticosteroids in patients with moderate to severe pemphigus.

Management of Pemphigus Vulgaris

INTRODUCTION

Pemphigus vulgaris (PV) is a chronic, autoimmune, vesiculobullous disease. As a result of the relative rarity of PV, published randomized controlled trials (RCTs) are limited, which makes it difficult to evaluate the efficacy of different treatment regimens in this disease. This also precludes conduct of a meta-analysis.

METHODS

English-language publications describing treatment outcomes of patients with PV were identified by searches of electronic databases through May 2015, and additionally by review of the bibliography of these publications. A total of 89 papers, which included 21 case reports, 47 case series, 8 RCTs, and 13 observational studies, were identified. The findings from these publications, including information on disease course and prognosis, medications used, treatment responses, and side effects, are summarized in the tables and text of this review.

RESULTS

Prior to availability of corticosteroid therapy, PV had a high fatality rate. Early publications from the 1970s reported high-dose, prolonged corticosteroid use and significant associated side effects. Later reports described use of corticosteroids along with steroid-sparing adjuvants, which allows a reduction in the total dose of corticosteroids and a reduction in observed mortality and morbidity. For the majority of patients in these reports, a long-term course on medications lasting about 5-10 years was observed; however, subgroups of patients requiring shorter courses or needing longer-term therapy have also been described. Early diagnosis of PV and early initiation of treatment were prognostic factors. In recent publications, commonly used initial regimens include corticosteroids in combination with mycophenolate or azathioprine; whereas, for patients with inadequate response to these regimens, adjuvants such as intravenous immunoglobulin (IVIg) or rituximab are used.

CONCLUSION

The review findings emphasize the importance of early diagnosis, early initiation of treatment, and use of steroid-sparing adjuvants to allow a reduced total dose and duration on corticosteroids. Also highlighted is the need for more RCTs.

Rituximab therapy improves recalcitrant Pemphigus vulgaris

Pemphigus is a severe life-threatening blistering disease associated with autoantibodies against cell adhesion proteins desmogleins 1 and 3. Patients with severe pemphigus commonly show high rates of relapse after conventional immunosuppressive therapy. The newly developed drug Rituximab showed impressing promises in the treatment of refractory pemphigus vulgaris (PV). In the present study the efficacy of a single course rituximab therapy in the treatment of PV was investigated. Eighteen patients with severe recalcitrant PV were recruited to this study. Pemphigus disease activity index (PDAI), anti-desmoglein 1 and anti-desmoglein 3 antibody titers, and percent of CD20 positive cells were measured at baseline, 10 ± 1, and 22 ± 2 weeks after rituximab therapy. Rituximab was given intravenously at dose 375 mg/m(2) once weekly for 4 weeks. Rituximab therapy caused a dramatic reduction in the PDAI, accompanied by decreases in anti-desmoglein 1 and anti-desmoglein 3 antibody titers over the follow-up course. The B-cell population decreased at the first follow-up, but returned to its baseline levels at the second follow-up. Rituximab therapy decreased the dose of immunosuppressive drugs required to control the disease. It seems that the rituximab may be effective and safe for treatment of refractory PV.

Vitamin D and skeletal health in autoimmune bullous skin diseases: a case control study

Background

The presence of hypovitaminosis D in patients with autoimmune bullous skin diseases, such as pemphigus vulgaris (PV) and bullous pemphigoid (BP), is debated. In a previous study we found an increased prevalence of vertebral fractures (VFx) and hypovitaminosis D in PV and BP patients. The present study extends the sample size of the previous one, for investigating the 25-hydroxyvitamin D (25OHVitD) levels in relation with the skeletal health and disease intensity in these patients.

Methods

The previous study was performed in 13 PV and 15 BP patients and 28 controls. Data from 39 additional patients (22 PV and 17 BP) were now added. Eventually, we studied 67 patients (35 PV, 32 BP, 51 females), aged 64.7 ± 16.9 years and 67 age- gender- and body mass index-matched controls. In all subjects, serum 25OHVitD, calcium and alkaline phosphatase (ALP) levels were measured, bone mineral density (BMD) was evaluated by Dual-energy X-ray. Absorptiometry at lumbar spine (LS) and femoral neck (FN) and the presence of VFx were ascertained by visual assessment from spinal radiographs. In patients, the disease intensity was evaluated by the autoimmune bullous skin disorder intensity score (ABSIS).

Results

As compared with controls, both PV and BP patients showed lower 25OHVitD (22.2 ± 11.1 vs 13.9 ± 8.3 ng/mL, p < 0.001 and 22.4 ± 14.9 vs 9.5 ± 7.7 ng/mL, p < 0.0001, respectively) and higher prevalence of severe hypovitaminosis D (22.9 vs 48.6%, p < 0.02 and 31.1 vs 75.0%, p < 0.0001, respectively) and VFx (28.6 vs 57.1%, p = 0.03 and 34.4 vs 62.5%, P = 0.02, respectively). In both PV and BP patients, LS and FN BMD did not differ from controls. In the whole patients’ group, ABSIS score was inversely associated with 25OHVitD levels (R = −0.36, p < 0.005), regardless of age (β = −3.2, P = 0.009).

Conclusions

PV and BP patients have an increased prevalence of hypovitaminosis D and VFx. The extended study shows, for the first time, that the 25OHVitD levels are inversely associated with disease intensity and that VFx occur in spite of a not reduced BMD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-015-0230-0) contains supplementary material, which is available to authorized users.

Refractory pemphigus foliaceus and Behçet's disease successfully treated with tocilizumab

Pemphigus foliaceus (PF) and Behçet's disease (BD) are immune-mediated conditions which are usually treated with corticosteroids, immunosuppressants, and, when refractory, with biologic agents. In both diseases, interleukin (IL)-6 serum levels are increased driving the immune-mediated inflammatory process. Tocilizumab is a humanized monoclonal antibody, targeting IL6-receptor, used in the treatment of rheumatoid arthritis. Besides the current indication, it has been recently administered to patients with refractory immune inflammatory diseases as an off-label treatment. Here, we report the case of a woman affected with PF and BD, who did not respond to corticosteroids, immunosuppressants, and biologic agents including adalimumab, anakinra, and infliximab. A complete, long-lasting, clinical, and serological remission was achieved only with tocilizumab. To the best of our knowledge, the association between PF and BD has never been reported. Moreover, only two cases of BD and no cases of PF treated with tocilizumab have been described to date. A literature review on the use of biologic agents on patients with PF and BD was also carried out.

Rituximab in the treatment of pemphigus vulgaris

INTRODUCTION

Rituximab is increasingly used in patients with pemphigus vulgaris (PV) who are nonresponders to conventional therapy.

METHODS

A PubMed search was conducted using the words pemphigus vulgaris and rituximab therapy from papers published between 2000 and 2012. Two protocols were used. In the lymphoma protocol, patients received four weekly infusions of rituximab (dose 375 mg/m(2)). The rheumatoid arthritis (RA) protocol consisted of two infusions of 1,000 mg each 15 days apart. The variables recorded from each study included clinical remission off or on therapy, relapse rate, incidence of serious adverse events, concomitant therapies, duration of follow-up, and when available, levels of B cells and autoantibodies.

RESULTS

Forty-two studies were found, which reported 272 patients; 180 were treated by the lymphoma protocol and 92 by the RA protocol. Both protocols were effective in treating recalcitrant PV. The lymphoma protocol had a lower response rate, relapse rate and serious infections, but higher mortality, and there were nonresponders. The RA protocol produced a higher response rate, relapse rate, number of infections, but lower mortality rate, and lacked nonresponders. The cumulative follow-up for patients treated with the lymphoma protocol was 15.44 months (range 1-41) and 21.04 months (range 8.35-29) for the RA protocol. A major concern in both protocols was the high infection rates, some of which were fatal. A different protocol using a combination of rituximab with intravenous immunoglobulin in a defined manner with a definitive endpoint, used in a limited cohort of patients, showed promising results.

CONCLUSION

Neither protocol produced a sustained clinical remission and both required continued systemic therapy. Before initiation of treatment, physicians should have a specific goal and endpoint and be aware of its potential side effects and lack of information on its long-term effects. Patients should be carefully monitored during and after therapy.

Successful treatment of pemphigus with biweekly 1-g infusions of rituximab: a retrospective study of 47 patients

BACKGROUND

Rituximab is increasingly being appreciated as a remarkably effective treatment for pemphigus, mostly concomitantly with other immunosuppressive medications. The majority of studies have used a single cycle of rituximab with the same dosage as approved for the treatment of lymphomas, ie, 375 mg/m(2) weekly × 4 weeks. Rituximab is also approved for the treatment of rheumatoid arthritis, with a different dosing regimen: 1000 mg × 2, days 1 and 15.

OBJECTIVE

We aimed to assess the clinical response of patients with pemphigus to a single cycle of rituximab at the dosage used in rheumatoid arthritis. We also evaluated the response to repeated cycles of rituximab.

METHODS

A total of 47 patients with pemphigus who were treated with rituximab at a dosage of 1000 mg × 2, days 1 and 15, most with concurrent immunosuppressive medications, were retrospectively studied.

RESULTS

Remission rates after the first treatment cycle reached 76%. Repeating the treatment further increased the remission rates to 91%. There was a 22% relapse rate at a median time of 8 months, but 75% of relapsing patients achieved remission again with additional cycles. The side-effect profile was similar to previous reports, except for an immediate postinfusion pemphigus exacerbation in 4 patients.

LIMITATIONS

This was a retrospective study with a limited follow-up period.

CONCLUSION

The rheumatoid arthritis dosage of rituximab was efficacious and well tolerated in patients with pemphigus. Patients who fail to achieve remission after 1 cycle or patients who relapse seem to benefit from repeated rituximab cycles.

Relevance of rituximab therapy in pemphigus vulgaris: analysis of current data and the immunologic basis for its observed responses

Treatment of pemphigus vulgaris (PV) patients with rituximab therapy has not been critically evaluated. This article will provide in significant detail the available data to date, in order to provide a clinical and immunologic basis for clinicians to decide how best to treat recalcitrant PV patients with rituximab. PV is an autoimmune blistering disorder that affects the skin and mucous membranes. The immunopathology is well characterized, including the target antigens. PV patients have traditionally been treated with systemic corticosteroids and adjuvant immunosuppressive therapies. Clinical remission has been achieved in roughly 30% of patients. However, many patients experience severe side effects from this immunosuppression, including death. B-cell depletion therapy with rituximab therapy has been used to treat several autoimmune diseases including PV. In this article, we examined the data on 153 patients with PV who have been treated with rituximab. Our focus is on the clinical response of the patients with emphasis on adjuvant therapies, dosing regimens, potential adverse events and mechanism of action related to B-cell modulation during therapy. Importantly, the use of rituximab has increased clinical remission rates to 65% including many patients who were able to discontinue all systemic medications. Finally, an expert commentary is provided, which includes suggestions for optimizing current therapy and recommends the future direction of the field. The authors strongly endorse the use of rituximab in treatment of PV patients, particularly those nonresponsive to or who develop serious side effects to conventional therapy. Proper monitoring of patients including peripheral B-cell counts and overt signs of infection are warranted, given the potential for prolonged B-cell depletion.

Rituximab therapy of recalcitrant bullous dermatoses

BACKGROUND

Rituximab is a monoclonal antibody directed against CD20 cell surface antigen of B-lymphocytes. Recent studies have demonstrated effectivity in recalcitrant bullous pemphigoid. The data available on other types of autoimmune bullous disease is more scant.

MAIN OBSERVATION

Here we report on the successful adjuvant use of rituximab in mucous membrane pemphigoid and pemphigus vulgaris in two patients with the most refractory course of disease. Both patients achieved a good clinical response.

CONCLUSIONS

Rituximab is a third line treatment of patients with pemphigus vulgaris and mucous membrane pemphigoid. In contrast to bullous pemphigoid, other bullous diseases do not always respond to a monotherapy with this monoclonal antibody. Nevertheless, biological therapy seems to work faster than established treatment in such cases. Risks and benefits of the treatment are discussed.

[Successful treatment of pemphigus foliaceus with rituximab. Report of 3 cases]

Treatment of autoimmune bullous diseases, especially of the pemphigus diseases, regularly requires the use of immunosuppressive drugs, often with insufficient clinical benefit but considerable side effects. A variety of autoimmune diseases (such as rheumatoid arthritis, lupus erythematosus, pemphigus vulgaris) have been successfully treated with rituximab, a chimeric monoclonal antibody against CD20, leading to a transient depletion of B cells. We report on three patients with pemphigus foliaceus who responded to rituximab after failing multiple other immunosuppressive therapies. We also examine the controversial issue of continuation therapy with rituximab in detail.

Current status on B-cell depletion therapy in autoimmune diseases other than rheumatoid arthritis

Since the approval of the chimeric anti-CD20 antibody rituximab for the treatment of adults with severe-to-moderate rheumatoid arthritis after an inadequate response to TNF blockade, B-cell depletion therapy has been used for the treatment of a broad range of refractory autoimmune disorders. Based on current experiences and a literature search, a systematic review and evaluation of the current status of B-cell depletion therapy in autoimmune diseases other than rheumatoid arthritis, including rheumatic, nephrologic, dermatologic and neurologic autoimmune entities, was performed by an international group of experts based at several academic centres. Although important questions remain about the value and place of B-cell depletion in autoimmune diseases other than RA, preliminary data indicate the value of this therapeutic approach in otherwise refractory patients. However, given the lack of robust data from large randomised controlled trials, anti-CD20 therapy should be considered on an individual basis in otherwise refractory patients and its use based on a risk/benefit net calculation.

Herpes Simplex Virus Infection and Pemphigus

Pemphigus is a group of autoimmune blistering diseases of skin and/or mucous membranes caused by the presence of antibodies against adhesion molecules on the cell surface of keratinocytes. In genetically predisposed patients, several factors, including drugs, physical agents, neoplasms, hormones, and viruses, notably herpes simplex virus (HSV), have been hypothesized to trigger or exacerbate the disorder. To clarify whether HSV infection represents an aetiopathogenetic factor for pemphigus or a consequence of the immunosuppressive treatment, skin and/or mucosal swabs from 35 patients with pemphigus vulgaris or pemphigus foliaceus were tested for HSV by polymerase chain reaction. Twenty-three of these patients were newly diagnosed, while the remaining 12 had had a previous diagnosis and were under treatment with low-dosage oral corticosteroids. Repeat swabs were taken two weeks after starting intensive immunosuppressive therapy in 8 HSV-negative patients. All skin swabs (n = 27) resulted negative for both HSV-1/2, while oral swabs (n = 30) were positive for HSV-1 in 5 out of the 12 patients who were being treated with oral corticosteroids, but in none (n = 19) of the non-treated group (p = 0.0067, χ2 test). Five out of the 8 patients with repeat swabs became positive for HSV-1, prompting us to start antiviral therapy. In conclusion, HSV is unlikely to be a triggering factor for pemphigus, but its presence in pemphigus lesions seems to be a frequent and early complication of immunosuppression.