Rituximab: applications in dermatology

Off-Label Uses of Rituximab in Dermatology

Purpose of Review

Rituximab has transformed the treatment of B-cell malignancies and rheumatoid arthritis in the past 2 decades. More recently, this anti-CD20 monoclonal antibody has seen increasing usage in the field of dermatology. This review highlights the evidence supporting its use in several important dermatologic conditions.

Recent Findings

Key recent findings include the 2018 FDA approval of rituximab for the treatment of moderate-to-severe pemphigus.

Summary

Data from randomized controlled trials have demonstrated the efficacy of rituximab in pemphigus, ANCA-associated vasculitis, and cryoglobulinemic vasculitis. More limited data suggests its use in recalcitrant cases of diseases such as pemphigoid, epidermolysis bullosa acquisita, and dermatomyositis. There is scarce evidence and mixed results for rituximab when studied in cutaneous polyarteritis nodosa and cutaneous lupus erythematosus.

Bullous systemic lupus erythematosus in females

Bullous systemic lupus erythematosus (BSLE) is a rare blistering presentation of systemic lupus erythematosus, typically affecting women with the highest incidence in those of African descent. The key pathogenic insult includes the formation of autoantibodies against type VII collagen, which weaken the basement membrane zone and lead to the formation of subepidermal blisters. The acute vesiculobullous eruptions in BSLE generally tend to affect photo-distributed areas, although they can arise unrelated to sun exposure (eg, mucous membranes, axillae). The bullae can arise from erythematous macules, inflammatory plaques, or previously normal skin. Their appearance can range from small, grouped vesicles reminiscent of lesions in dermatitis herpetiformis to large, tense blisters, similar to bullous pemphigoid. Internal organ involvement occurs in up to 90% of those affected. This mostly includes lupus nephritis (classes III–V, lifetime prevalence of up to 90%), arthralgias/arthritis, and cytopenias, while serositis and neuropsychiatric involvement are rare. First-line management with dapsone should be considered in mild disease with stable underlying systemic lupus erythematosus. As discussed in this review, the off-label use of rituximab (an anti-CD20 B-cell depleting agent) has been shown to be safe and effective in several refractory cases of BSLE unresponsive to dapsone, glucocorticoids, or steroid-sparing immunosuppressants.

Biologics in Dermatology: Off-Label Indications

Skin and subcutaneous diseases affect millions of people worldwide, causing significant morbidity. Biologics are becoming increasingly useful for the treatment of many skin diseases, particularly as alternatives for patients who have failed to tolerate or respond to conventional systemic therapies. Biological therapies provide a targeted approach to treatment through interaction with specific components of the underlying immune and inflammatory disease processes. Advances in the understanding of disease pathophysiology for inflammatory skin diseases and in drug development have ushered in biologic therapies in dermatology. Biologic therapies are molecules that target specific proteins implicated in immune-mediated disease. This review article highlights the increasing evidence base for biologics in dermatology for off-label use.

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.

Future therapies for pemphigus vulgaris: Rituximab and beyond

The conventional treatment for patients with pemphigus vulgaris (PV) centers on global immunosuppression, such as the use of steroids and other immunosuppressive drugs, to decrease titers of antidesmoglein autoantibodies responsible for the acantholytic blisters. Global immunosuppressants, however, cause serious side effects. The emergence of anti-CD20 biologic medications, such as rituximab, as an adjunct to conventional therapy has shifted the focus to targeted destruction of autoimmune B cells. Next-generation biologic medications with improved modes of delivery, pharmacology, and side effect profiles are constantly being developed, adding to the diversity of options for PV treatment. We review promising monoclonal antibodies, including veltuzumab, obinutuzumab (GA-101), ofatumumab, ocaratuzumab (AME-133v), PRO131921, and belimumab.

Novel applications of Rituximab in dermatological disorders

Rituximab is a monoclonal therapeutic anti-CD20 antibody that has been approved for use in lymphoma and rheumatoid arthritis. Over the past decade several reports based on case series and observational studies have recorded the benefits of rituximab in particular groups of dermatological patients. Off-label use of rituximab in many dermatological indications is not uncommon in many countries in the world. This article reviews the available data that may be of use to the practicing dermatologist. Because of its potential complications, paucity of clinical data, and cost considerations, rituximab is favoured only when standard systemic therapies fail or corticosteroids are absolutely contraindicated. Further research is required in this field.

B cells: the old new players in reproductive immunology

Reproductive immunology research has long focused on T cell responses to paternal antigens and tolerance mechanisms supporting fetal well-being. The participation of B cells herein was not widely studied. Because of the fascinating immunological uniqueness of pregnancy, it is however to be expected that such pleiotropic cells play a considerable role. In fact, on the one hand B cells contribute toward pregnancy tolerance by secreting the immunomodulatory cytokine IL-10 but on the other hand can seriously harm pregnancy because of their capacity of producing autoantibodies. As for protective B cells, new evidences in mouse models arise suggesting that IL-10 producing B cells, the so-called B10 cells, help in maintaining tolerance toward semi-allogenic fetal antigens. They may be also important to fight danger signals at the fetal-maternal interface as, e.g., in the case of infections with the aim to restore the disrupted fetal tolerance. In human pregnancies, IL-10 producing B cells increase with pregnancy onset but not in the case of spontaneous abortions. In vitro, they are able to suppress TNF-α production by T cells from pregnant individuals. Their generation and functionality will be discussed throughout this review article. B cells can be deleterious to pregnancy as well. Aberrant B cell compartment is associated with obstetric pathologies. In particular, the capacity of B2 cells to produce specific autoantibodies or of B-1a B cells to secrete natural autoantibodies that can turn autoreactive will be discussed herein.

Off-label use of rituximab in dermatology: pemphigus treatment

Since its approval in 1997 by the FDA (United States Food and Drug Administration), rituximab has been used for certain B-cell lymphomas and treatment-resistant rheumatoid arthritis. Nevertheless, over the past 14 years, many case reports have demonstrated the efficacy of off-label rituximab in several dermatological inflammatory conditions. This study describes two cases of pemphigus vulgaris and two cases of pemphigus foliaceous that were treated with rituximab at 375 mg/m2 once a week for 4 weeks, and that responded well to treatment.

Rituximab for the treatment of lupus erythematosus panniculitis

Lupus erythematosus panniculitis (LEP) or lupus profundus (LP) is a clinical variant of lupus eryhematosus that involves the deep dermis and the subcutaneous fat and is associated with tender subcutaneous nodules or plaques, with occasional ulceration, atrophy, and scarring. The management of this entity can be difficult because of the lack of response to conventional treatments, such as systemic steroids and antimalarials. The two patients of this study presented LP refractory to several therapies that demonstrated a remarkable improve to the infusion of the anti-CD20 monoclonal antibody, rituximab at a dosage of 375 mg/m²/week. After the first infusion, painful lesions had resolved without the appearance of new lesions. Rituximab may be an effective treatment for patients with LP when other therapies are ineffective. To date, there is only one case report of LEP treated with rituximab in the literature.

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.

Treatment-resistant elephantiasic thyroid dermopathy responding to rituximab and plasmapheresis

A 44-year-old woman was diagnosed with Graves' disease in 1995 and over the following 12 months developed thyroid dermopathy (pretibial myxoedema). Despite being trialled on multiple recognized therapies over the course of 11 years, the patient's dermopathy progressively worsened. She developed ocular proptosis, elephantiasic thyroid dermopathy and acropachy in both hands. In mid 2006, the patient was started on rituximab and plasmapheresis, with rapid response. The patient's condition stabilized and in October 2009 at the age of 58 years she was able to cease therapy.

[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.

Refractory subacute cutaneous lupus erythematosus successfully treated with rituximab

A 48-year-old woman presented with pruritic, scaly, annular plaques over her upper back and chest that were clinically, serologically and histologically characteristic of subacute cutaneous lupus erythematosus (SCLE). She failed to respond to conventional treatment, which included high-dose hydroxychloroquine, methotrexate, prednisolone, chloroquine, acitretin, thalidomide, dapsone and azathioprine. Subsequently treated with intravenous rituximab 375 mg/m(2) weekly for 4 weeks, she remained on adjuvant oral hydrochloroquine 600 mg daily and topical clobetasol propionate 0.05% ointment as required. Clearing of annular plaques was noted 8 weeks after the initial course of rituximab. By 12 weeks there were no new lesions and only post-inflammatory hyperpigmentation remained. Both hyper- and hypopigmentation, which is more common, are consistent with SCLE lesion regression. Skin lesions recurred 11 months later; however, no further lesions occurred after re-introduction of rituximab therapy. The treatment was well tolerated. A maintenance regimen of rituximab, 375 mg/m(2) every 8 weeks for 2 years, was commenced 3 months after completing the second course of treatment, with ongoing disease remission. Rituximab appears to have activity in refractory SCLE and clinical trials are required to further assess this potential therapy.