Rituximab in refractory cutaneous polyarteritis

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.

Biologic drugs in the treatment of polyarteritis nodosa and deficit of adenosine deaminase 2: A narrative review

Polyarteritis nodosa (PAN) is a medium vessels vasculitis variously involving different organs and systems, sometimes with an aggressive course, leading to death or disability in a significant number of cases. First-line treatment usually relies on steroids and classical immunosuppressants, but a growing number of case reports and small case series shows the potential role of biologic drugs, mostly anti-tumor necrosis factor (TNF)-α agents, in inducing and maintaining remission in patients affected by PAN. Similarly, the recently described autoinflammatory disease named deficit of adenosine deaminase 2 (DADA2), considered by several experts as a more precocious and aggressive variant of PAN, seems to respond to a prompt treatment with TNF-α inhibitors. The aim of this review is to collect all existing evidences about the use of biologic drugs in PAN and DADA2. Fifty-one articles published during the last 15 years were retrieved, including 58 and 76 patients affected by PAN and DADA2, respectively, and treated with biologic drugs. The majority of subjects was treated with TNF-α inhibitors, whose effectiveness was reported in the treatment of such difficult-to-manage diseases, particularly in DADA2. Among the other biologic drugs, Tocilizumab was successfully employed in some subjects affected by PAN who did not respond to TNF-α inhibitors, while Rituximab did not give substantial benefits neither in PAN nor in DADA2. Only few data exist about the role of Janus-kinase inhibitors and anti-IL1 agents. This study provides the first comprehensive assessment of biologic agents in both PAN and DADA2, with encouraging results especially in the context of TNF-α inhibitors. Nevertheless, due to the lack of prospective, randomized, case control studies, further efforts should be made in order to fully elucidate the role of these drugs in such rare and life-threatening conditions.

Unmet Needs in the Pathogenesis and Treatment of Vasculitides

Despite the progress in the last years on the field of vasculitides, there are several unmet needs regarding classification, disease activity assessment, predictors of flares and complications, and type of treatment for the different forms. The 1990 American College of Rheumatology (ACR) classification criteria currently used to define giant cell arteritis and Takayasu arteritis were designed to discriminate between different types of vasculitides but not to differentiate vasculitis from other disorders. Recently, efforts have been made to overcome the shortcomings of the ACR criteria. The lack of an accepted definition of disease activity in large-vessel vasculitides presents a major challenge in creating useful and valid outcome tools for the assessment of disease course. Identification of predictors of flares can aid in optimizing therapeutic strategies, minimizing disease flares, and reducing treatment-related side effects. It is furthermore important to recognize and characterize the risk factor that might predict the manifestations associated with poor outcome and prognosis. Two RCTs have evidenced the efficacy of tocilizumab in addition to glucocorticoids (GCs) in the treatment of giant cell arteritis (GCA). However, the role of tocilizumab or other biological agents without GCs needs to be investigated. Recent observational studies have suggested that rituximab is also effective in patients with eosinophilic granulomatosis with polyangiitis and in antineutrophil cytoplasmic antibodies (ANCA)-negative patients with granulomatosis with polyangiitis and microscopic polyangiitis. Rituximab or anti-TNF alfa may represent a possible alternative therapy in case of refractory or difficult to treat polyarteritis nodosa (PAN) patients. The new International Criteria for Behçet's Disease have shown a better sensitivity and a better accuracy compared to the older International Study Group on Behçet's Disease criteria. The EULAR recommendations for the management of Behçet's disease (BD) have been recently updated. However, the treatment of refractory disease is still a real challenge.