The emerging role of rituximab in autoimmune blistering diseases

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.

Intralesional injection of biosimilar rituximab in recalcitrant mucocutaneous lesions of patients with pemphigus vulgaris: A pilot study

The efficacy of intravenous rituximab (RTX) in patients with pemphigus have been shown in the previous studies. The study aimed to investigate the effectiveness of intralesional injection of RTX in the healing of pemphigus lesions, with lower doses and probable better safety profile than intravenous RTX. Eleven Pemphigus patients with recalcitrant lesions received two intralesional injections of biosimilar RTX, 5 mg/cm² . During 6 months follow-up, Pemphigus Disease Area Index, the patients' satisfaction, quality of life, the disease activity, the number and size of lesions, the anti-desmoglein (Dsg) 1 and 3 antibodies and the count of CD4+ and CD19+ cells were assessed. All patients were in partial remission on therapy. The absolute count of CD19+ B cells showed a statistically significant decline (P = .006). The percentage of CD4 + T lymphocytes increased 2 weeks after injection and decreased 2 weeks later (P = .01). The average number and size of lesions decreased. The concentration of anti-Dsg 3 antibody decreased insignificantly during the study. The severe pain during the injection was considered as the main complication. At the end of the study, two patients were in complete remission on therapy, and the other nine remained in partial remission on therapy. Few side effects resulting from intralesional injection of RTX and enhanced quality of life of the patients were considered as the valuable achievements of this study. The results showed that although a low dose of RTX leads to a significant decrease of CD19+ B lymphocytes, it did not show parallel clinical effectiveness.

Treatment of pemphigus vulgaris: part 2 - emerging therapies

Introduction: Corticosteroids and immunosuppressive agents have been the mainstay for the treatment of pemphigus vulgaris (PV). While they have benefited patients, they have been associated with the risks of prolonged immune suppression and a high incidence of significant and catastrophic side effects. Relapses are common. Novel agents promising targeted therapies, that may provide better outcomes, are being studied. Areas covered: Recently rituximab with corticosteroids has been recommended as the first-line treatment for PV. A number of known and new therapeutic agents currently investigated are BAFF, P13K, BTK inhibitors along with the use of IVIg and CAR-T therapy. The possible role of these therapeutic targets in the pathophysiology appears to be the rationale for the treatment of this potentially fatal disease. Expert opinion: While there is significant enthusiasm for these therapies, certain concerns and consequences are being under-discussed. None of the current clinical trials in progress are specific for PV, except possibly CAR-T therapy. The major issue(s) that are unclear is whether these therapies would be successful in providing long-term clinical remissions. Will these therapies require additional agents to be effective? Will the benefits be limited in duration? The answers to many questions will determine their final place in the algorithm for the treatment of PV.

Biological therapy of autoimmune blistering diseases

INTRODUCTION

Autoimmune blistering skin diseases are a group of disorders subdivided according to the location of blister formation: intraepidermal blistering in the pemphigus group and subepidermal in the pemphigoid group. These conditions are clinically heterogeneous and are treated with systemic corticosteroids and/or other forms of immunosuppression on the basis of clinical subtype and disease severity. These approaches may not be effective for the induction and maintenance of clinical response or need to be stopped because of intolerable side effects.

AREAS COVERED

Biological therapies can represent a valid alternative strategy in various autoimmune blistering disorders and this review article will address this issue with a special focus on pemphigus vulgaris and bullous pemphigoid. These biological approaches are designed to target B cells, autoantibodies, complement proteins, and several cytokines.

EXPERT OPINION

Innovative strategies for the treatment of autoimmune blistering conditions primarily depend on the use of drugs with a high degree of specificity targeting crucial steps in the immunopathology of these disorders. Novel biological agents offer treatment alternatives to patients with autoimmune blistering conditions by targeting B cells, pathogenic autoantibodies, complement and cytokines.