Adjuvant rituximab in the treatment of pemphigus vulgaris: a phase II clinical trial

Review of an Anti-CD20 Monoclonal Antibody for the Treatment of Autoimmune Diseases of the Skin

Biologic therapies targeting B-cells are emerging as an effective strategy to treat a variety of immune-mediated diseases. One of the most studied B-cell-targeted therapies is rituximab, an anti-CD20 monoclonal antibody that exemplifies B-cell depletion therapy and has served as the prototype for other anti-CD20 monoclonal antibodies and the development of biosimilars. While there are multiple studies on the use of rituximab in dermatology, a comprehensive review of rituximab therapy in autoimmune skin conditions is lacking. In this literature review, we summarize indications, treatment efficacy, and safety of rituximab among common autoimmune diseases of the skin: pemphigus vulgaris, cutaneous lupus erythematous, dermatomyositis, systemic sclerosis, thyroid dermopathy, autoimmune pemphigoid diseases, and cutaneous vasculitis diseases. Existing data on rituximab support the approach of rituximab, biosimilars, and newer B-cell-targeting therapies in immune-mediated cutaneous diseases. Overall, rituximab, which targets CD20, provides an effective alternative or concomitant option to traditional immunosuppressants in the management of various autoimmune diseases of the skin. Further studies are necessary to expand the understanding and possible utility of B-cell-targeted therapies among autoimmune skin diseases.

Autoimmune Pemphigus: Latest Advances and Emerging Therapies

Pemphigus represents a group of rare and severe autoimmune intra-epidermal blistering diseases affecting the skin and mucous membranes. These painful and debilitating diseases are driven by the production of autoantibodies that are mainly directed against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1). The search to define underlying triggers for anti-Dsg-antibody production has revealed genetic, environmental, and possible vaccine-driven factors, but our knowledge of the processes underlying disease initiation and pathology remains incomplete. Recent studies point to an important role of T cells in supporting auto-antibody production; yet the involvement of the myeloid compartment remains unexplored. Clinical management of pemphigus is beginning to move away from broad-spectrum immunosuppression and towards B-cell-targeted therapies, which reduce many patients’ symptoms but can have significant side effects. Here, we review the latest developments in our understanding of the predisposing factors/conditions of pemphigus, the underlying pathogenic mechanisms, and new and emerging therapies to treat these devastating diseases.

A review of reported infectious events following rituximab therapy in pemphigus patients

Pemphigus is a rare autoimmune blistering condition that used to be fatal before the introduction of corticosteroid (CS) and immunosuppressive agents. Rituximab is a monoclonal anti-CD-20 antibody that induces the pathologic B-cells apoptosis with significant efficacy in the treatment of pemphigus. The application of rituximab can lead to infectious events. We aim to review the reported infectious events in pemphigus patients who previously received rituximab and classify them based on the causative agents. A thorough search of PubMed was conducted using the keywords "rituximab," "pemphigus," "infection," "viral disease," "viral infection," "complication," "efficacy" and their combinations also applying their equivalent Mesh terms and including the references cited in each study. All studies that mentioned at least one infectious event were included. A total of 77 infectious events in 68 patients were reported in the literature out of which the most reported causative agent was viral but the most fatal one found to be bacterial. Although rituximab therapy has shown promising results in controlling pemphigus patients mainly the refractory cases, given possible fatal outcomes, we believe the medical profile of the patients before initiating the therapy warrants careful examination to search for any risk factors or predisposing conditions.

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.

Skin and sepsis: contribution of dermatology to a rapid diagnosis

In patients who develop sepsis, whether due to primary, secondary or metastatic lesions, the skin is frequently affected. However, there are unresolved aspects regarding the general clinical manifestations in the skin or the prognosis and/or therapeutic implications. The main challenge in the approach to sepsis is its early diagnosis and management. In this review, we address the sepsis-skin relationship and the potential impact of early dermatological intervention on the septic patient through ten basic questions. We found little evidence of the participation of the dermatologist in sepsis alert programs. There are early skin changes that may alert clinicians on a possible sepsis, such as skin mottling or variations in acral skin temperature. In addition, the skin is an accessible and highly cost-effective tissue for etiological studies of some forms of sepsis (e.g., meningococcal purpura) and its involvement defines the prognosis of certain patients (e.g., infective endocarditis).

Treatment of Pemphigus with Rituximab: Real-Life Experience in a Cohort of 117 Patients in Israel

BACKGROUND

A combined regimen of rituximab with corticosteroids for the treatment of pemphigus was effective in a prospective randomized controlled trial.

OBJECTIVE

To assess real-life response to rituximab in patients with pemphigus.

METHODS

A retrospective cohort of patients with pemphigus treated with ≥1 rituximab cycles (1,000 mg on days 0 and 14). The primary outcome was remission rate after 1 cycle. For efficacy analyses, a minimal 6-month follow-up was required. Adverse events were assessed in all patients.

RESULTS

The cohort included 117 patients for safety analysis, 108 for efficacy analysis (median follow-up of 33 months). All but one received concomitant corticosteroids, a third also received adjuvants. Overall, 80/108 patients (74%) achieved remission after the first rituximab cycle at a median of 5.5 months. Relapses occurred in 39 patients (49%) at a median of 18 months. Repeating treatment in relapsed patients increased remission rates to 75 and 88% after the second and third cycles, respectively. Adverse events were similar to those of previous publications. Two elderly patients died of infections attributable to rituximab combined with high-dose corticosteroids.

CONCLUSION

In a large real-life long-term cohort, rituximab with corticosteroids ± adjuvants induced remission in most patients with pemphigus, with relatively favorable safety. Repeating treatment following relapse or remission failure was beneficial.

A Comparative Study to Evaluate the Efficacy and Cost of Rituximab versus Dexamethasone Cyclophosphamide Pulse in Patients of Pemphigus Vulgaris

Introduction:

Rituximab is slowly getting recognized as a promising steroid-sparing agent in the treatment of moderate to severe cases of pemphigus vulgaris (PV). We evaluated and compared the effectiveness, safety, and cost of therapy of rituximab versus dexamethasone cyclophosphamide pulse (DCP) in Indian patients with PV.

Materials and Methods:

It is a retrospective data analysis, from the Immunobullous disease clinic in a tertiary centre of eastern India, of management of PV. In our institute we use either rituximab or DCP for the management of moderate to severe cases of PV, depending on that we retrospectively divided the treated cases of PV in two groups. Patients who were treated with rheumatoid arthritis (RA) protocol of rituximab were considered to be group 1. Patients who were treated with DCP were included in group 2. Response was assessed by pemphigus area, and activity score (PAAS), Dermatology life quality index (DLQI); photographic documentation, and blood parameters were monitored.

Results:

Both groups showed significant improvement in PAAS and DLQI, the improvement was faster and well sustained in the rituximab group. In terms of safety and development of new vesicles, rituximab had a better profile with only 1 patient having adverse effects and none with new vesicles as compared to DCP (3 had adverse effects and 2 developed new vesicles).

Conclusions:

Rituximab offers the advantage of early and prolonged remission, lesser adverse effects, better effectiveness, less risk of relapses, faster improvement of PAAS, and DLQI. Though rituximab is an expensive drug, but on evaluating the cost of whole therapy, it was seen that rituximab infusions are actually cheaper compared to DCP pulse. We suggest, rituximab can be used as the first-line of therapy for pemphigus vulgaris in the Indian context.

Clinical and biological activity of rituximab in the treatment of pemphigus

B-cells are major effector cells in autoimmunity since they differentiate into plasmocytes that produce pathogenic auto-antibody such as anti-desmoglein antibodies in pemphigus patients. Major advances were obtained using whole B-cell depleting therapies including anti-CD20 antibodies in refractory pemphigus patients that lead to rituximab approval in pemphigus patients in EU and USA. This review summarizes the data supporting the efficacy of rituximab in pemphigus and provides an overview of the reported immunological changes underlying its therapeutic action. Short and long-term remission in pemphigus is explained by the removal of autoreactive B-cells involved in the production of pathogenic IgG auto-antibodies and by enhancement of the appearance of regulatory B-cells that could maintain long term immune tolerance.

Pemphigus Vulgaris: Short Time to Relapse in Patients Treated in a Danish Tertiary Referral Center

Pemphigus vulgaris is an autoimmune skin disorder with development of blisters in the skin and mucosa, and it can be a life-threatening disease if not treated. Corticosteroids have been a cornerstone for treating PV, but because of side effects the treatment is combined with other conventional immune modulating drugs and rituximab. The Danish treatment protocol for pemphigus vulgaris is similar to the other Scandinavian countries, and therefore this study is of importance for clinicians in the Scandinavian countries as well as other European countries. We retrospectively identified all patients with Pemphigus vulgaris in our tertiary center over a 7-year period in order to register patient characteristics, treatment, adverse events, comorbidities and the effect of prednisolone dose on remission. In this study 19 patients met the inclusion criteria and remission was seen after a mean of 19.9 weeks, and relapse was seen in 50% after the mean time of 15 weeks. Time to relapse in our study is relatively short compared to studies in which rituximab is used as a first-line drug in treating pemphigus vulgaris.

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.

Rituximab: A Magic Bullet for Pemphigus

INTRODUCTION

Pemphigus, an autoimmune disease, was fatal before the era of corticosteroids. With the advent of steroids, mortality decreased but morbidity was present due to the side effects of high dose steroids. Newer drugs targeted at the molecular level are said to have fewer side effects and improved effectiveness.

AIM

The aim of our study was to assess the effectiveness of one such drug, Rituximab, a biological, in treating pemphigus vulgaris and to identify common adverse events.

MATERIALS AND METHODS

It was an open label prospective interventional study, conducted from September 2013 to May 2015, in the Department of Dermatology, Stanley Medical College, Chennai, Tamil Nadu, India. Twenty patients with pemphigus were included in the study. Ten were refractory to conventional therapy and 10, new cases. Patients who satisfied inclusion and exclusion criteria were included in the study after informed, written consent. Rituximab was administered according to Rheumatoid arthritis protocol. The patients were followed up as out patients after discharge, end points and adverse events were noted.

RESULTS

There were 14 females (70%) and six males (30%). The mean age of the study group was 41.35 years. The mean disease duration was 11.7 months. The mean duration of follow up being 14.25 months. After rituximab, 13 patients remained in remission for varying periods of 3-22 months. The mean duration of complete remission off- treatment with Dexamethasone Cyclophosphamide Pulse (DCP) was 3.6 months; with rituximab it was 8.8 months. Seven (35%) patients relapsed during the study of whom six had received rituximab after being refractory to conventional treatment. Patients who relapsed had higher mean disease duration (21 months) than the remission group (6.384 months). Two patients (10%) developed immediate adverse events. Six patients (30%) developed late adverse events the commonest being reactivation of herpes labialis.

CONCLUSION

Rituximab was effective in treating pemphigus vulgaris, was significantly better than conventional treatment, decreased the need for additional steroids and other immunosuppressants and induced prolonged remission. Rituximab was more effective when given early in the disease process. Further studies may highlight the need for additional cycles of rituximab to maintain sustained remission.

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.

[Pemphigus. Model disease for targeted therapy]

BACKGROUND

Pemphigus is a severe bullous autoimmune dermatosis that represents a clinical challenge despite high-dose immunosuppressive therapy due to the therapy-related comorbidities and the lack of long-term control of disease activity.

OBJECTIVES

Which targeted therapies are currently used in pemphigus and which innovative therapeutic strategies are in clinical development?

MATERIALS AND METHODS

A review of the literature in PubMed was performed under consideration of the current guideline for the treatment of pemphigus as well as of our own results. Discussion of basic findings and results of targeted therapies in autoantibody-mediated autoimmune disorders were taken into account.

RESULTS

Immunapheresis and high-dose intravenous immunoglobulins with the aim of reducing circulating autoantibodies have been successfully used in the treatment of pemphigus. Depletion of autoreactive B-lymphocytes provides the rationale for the use of the monoclonal anti-CD20 antibody rituximab which demonstrated long-term clinical remission of pemphigus in clinical trials. Current developments include the investigation of humanised B-cell depleting antibodies in other B-cell driven autoimmune disorders as well as the identification of new cellular and molecular target structures that are essential in the humoral autoimmune cascade and exert important immune regulatory functions, respectively.

CONCLUSIONS

The well-characterised basic pathogenesis of pemphigus results in targeted therapies. Currently, therapies aiming at rapid reduction of circulating autoantibodies and the depletion of autoreactive B-cells are in clinical use. More cellular and molecular target structures are being investigated in other autoantibody-driven autoimmune disorders and they provide promising candidates for innovative pathogenesis-related therapeutic strategies in pemphigus in the future.

Recurrent venous thrombosis in an adequately anticoagulated patient with pemphigus vulgaris

Background

Several autoimmune skin disorders are characterised by an increased risk of thrombosis, with bollous pemphigoid carrying a higher risk than pemphigus vulgaris (PV). We describe the case of a middle aged gentleman who developed recurrent venous thromboembolism despite adequate oral anticoagulation during very active PV that required escalation of treatment to bring the disease under control.

Case presentation

In May 2014 a 49 year gentleman was admitted for widespread mucocutaneous blistering diagnosed as PV by histology and immunofluorescence. After 6 weeks of treatment with systemic steroids and azathioprine the patient developed pulmonary emboli and started oral anticoagulation with warfarin. In late September, the patient re-presented with a severe flare of PV and a recurrent deep vein thrombosis despite oral anticoagulation within therapeutic range. Warfarin was changed to subcutaneous low molecular heparin in therapeutic dose while treatment for pemphigus was escalated: first azathioprine was switched to mycophenolate mofetil and the steroids dose increased; then due to poor response, intravenous immunoglobulins were given for three courses and finally he received four infusions of Rituximab that induced sustained remission. In April 2015 the dose of mycophenolate was decreased but anticoagulation was continued until the beginning of July 2015 to ensure that decreasing immune suppression did not allow the emergence of another flare with attendant thrombotic risk.

Conclusion

The case highlights the risk of thrombosis and re-thrombosis in aggressive PV and demands further clinical research in this area to assess the need for thromboprophylaxis in aggressive bollous skin disease.

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.

The emerging role of rituximab in autoimmune blistering diseases

Rituximab is a chimeric monoclonal antibody that selectively binds to the CD20 molecule on B cells, resulting in their lysis. In autoimmune blistering diseases, the auto-antibody-producing B cells are destroyed and auto-antibody levels are reduced or eliminated. In the majority of patients, rituximab produces rapid clinical response and early resolution. In part, this accounts for the increased use of rituximab. Rituximab does not distinguish normal from pathologic B cells. Hence, shortly after its use, B-cell levels are zero and remain so for several months. In most patients, the use of systemic corticosteroids and immunosuppressive agents are continued after rituximab therapy, while their dosages are significantly decreased. In the majority of patients rituximab is used according to the protocol used in treating lymphoma patients or patients with rheumatoid arthritis. Approximately 50% of patients experience a relapse, requiring additional therapy. Serious adverse events and fatal outcomes have been reported, although their incidence is less than that observed with conventional therapy. Nonetheless, the causes, i.e. infections and septicemia, are similar. Several gaps exist in our understanding of how to optimally benefit from the use of this valuable biological agent. Future studies need to be targeted in designing and implanting protocols that maximize the benefit of rituximab and result in producing sustained prolonged remissions with minimal adverse events and a high quality of life.

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.