Checkpoint inhibitor-associated bullous cutaneous immune-related adverse events: a multicentre observational study

[Drug-related exanthema under immunotherapy and targeted oncological therapy]

BACKGROUND

Oncological therapies can cause a variety of mucocutaneous adverse events. Exanthematous adverse events can be challenging in the context of the urgent need for cancer treatment due to their spread, sometimes rapid progression, and mucous membrane or organ involvement.

MATERIALS AND METHODS

This article provides an overview of the most important exanthematic dermatoses as side effects of modern drug-based tumor therapies with diagnostic and therapeutic information for clinicians, taking into account the current literature and guidelines.

RESULTS

Exanthematous adverse events of immune checkpoint inhibitors, EGFR antagonists, kinase inhibitors, bispecific T‑cell engagers, and the CCR4 inhibitor mogamulizumab are reviewed in detail.

CONCLUSIONS

Cutaneous side effects are common across all drug classes and cover a broad spectrum. While some adverse events are specific to one drug class, many exanthemas can occur with both oncological immunotherapies and various targeted therapies. A reliable diagnosis, dose adjustment or discontinuation of the offending agent in consultation with the treating oncologists and appropriate symptomatic therapy are important for correct management. In the case of severe, life-threatening drug reactions, however, permanent discontinuation of the drug is essential.

From Molecular Insights to Clinical Perspectives in Drug-Associated Bullous Pemphigoid

Bullous pemphigoid (BP), the most common autoimmune blistering disease, is characterized by the presence of autoantibodies targeting BP180 and BP230 in the basement membrane zone. This leads to the activation of complement-dependent and independent pathways, resulting in proteolytic cleavage at the dermoepidermal junction and an eosinophilic inflammatory response. While numerous drugs have been associated with BP in the literature, causality and pathogenic mechanisms remain elusive in most cases. Dipeptidyl peptidase 4 inhibitors (DPP4i), in particular, are the most frequently reported drugs related to BP and, therefore, have been extensively investigated. They can potentially trigger BP through the impaired proteolytic degradation of BP180, combined with immune dysregulation. DPP4i-associated BP can be categorized into true drug-induced BP and drug-triggered BP, with the latter resembling classic BP. Antineoplastic immunotherapy is increasingly associated with BP, with both B and T cells involved. Other drugs, including biologics, diuretics and cardiovascular and neuropsychiatric agents, present weaker evidence and poorly understood pathogenic mechanisms. Further research is needed due to the growing incidence of BP and the increasing identification of new potential triggers.

How to recognize and manage skin toxicities associated with immune checkpoint inhibitors: a practical approach

Immune checkpoint inhibitors (ICIs) have revolutionized treatment strategies in the field of oncology. Their favourable outcomes in terms of efficacy and side-effect profile can be thwarted by the development of immune-related adverse events (irAEs). Cutaneous irAEs are relatively common in patients undergoing immunotherapy and include common inflammatory dermatoses (e.g. eczematous, psoriasiform and lichenoid phenotypes), maculopapular eruptions, pruritus and immunobullous disorders. Most of these reactions can be managed without ICIs having to be stopped completely; however, there are some life-threatening toxicities that dermatologists and oncologists should be aware of. In this review, we focus on how to recognize the commonly associated cutaneous irAEs, touching upon rarer reactions and red flags; finally, we provide guidance on their management.

New insights into programmed cell death protein 1 blockade-associated cutaneous immune-related adverse events

Cutaneous side-effects associated with immune checkpoint blockade occur in more than half of patients treated with CTLA-4 and PD-1 inhibitors, and are frequently encountered by dermatologists. The molecular mechanism of cutaneous side-effects is incompletely understood but holds important clues about immune tolerance and the antitumor immune response in the skin. A new landmark study published in Nature suggests a critical functional role for the checkpoint receptor PD-1 in restraining self-reactive T cells, which could help explain how some checkpoint-associated cutaneous side-effects arise.

Pemphigus vulgaris as an immune-related adverse event in recurrent metastatic esophageal squamous cell carcinoma treated with ipilimumab plus nivolumab: a case report and literature review

Ipilimumab plus nivolumab therapy is approved for patients with unresectable advanced esophageal squamous cell carcinoma (ESCC). Although a combination of immune checkpoint inhibitors (ICIs), compared to conventional chemotherapy, can improve overall survival in patients with advanced ESCC, this increases the incidence of immune-related adverse events (irAEs). Here, we describe an ESCC case that developed pemphigus vulgaris (PV), an extremely rare cutaneous irAE, during ipilimumab plus nivolumab treatment. The patient achieved a partial response to treatment. The PV was successfully managed after the cessation of ipilimumab and the use of a topical steroid. We should thus re-treat ESCC with nivolumab monotherapy. In the era of ICIs as standard cancer therapeutics, diagnostic criteria for blistering diseases need to be established to properly manage patients with cutaneous irAEs.

Autoimmune bullous dermatoses in cancer patients treated by immunotherapy: a literature review and Italian multicentric experience

Cutaneous immune-related adverse events are frequently associated with immune checkpoint inhibitors (ICIs) administration in cancer patients. In fact, these monoclonal antibodies bind the cytotoxic T-lymphocyte antigen-4 and programmed cell death-1/ligand 1 leading to a non-specific activation of the immune system against both tumoral cells and self-antigens. The skin is the most frequently affected organ system appearing involved especially by inflammatory manifestations such as maculopapular, lichenoid, psoriatic, and eczematous eruptions. Although less common, ICI-induced autoimmune blistering diseases have also been reported, with an estimated overall incidence of less than 5%. Bullous pemphigoid-like eruption is the predominant phenotype, while lichen planus pemphigoides, pemphigus vulgaris, and mucous membrane pemphigoid have been described anecdotally. Overall, they have a wide range of clinical presentations and often overlap with each other leading to a delayed diagnosis. Achieving adequate control of skin toxicity in these cases often requires immunosuppressive systemic therapies and/or interruption of ICI treatment, presenting a therapeutic challenge in the context of cancer management. In this study, we present a case series from Italy based on a multicenter, retrospective, observational study, which included 45 patients treated with ICIs who developed ICI-induced bullous pemphigoid. In addition, we performed a comprehensive review to identify the cases reported in the literature on ICI-induced autoimmune bullous diseases. Several theories seeking their underlying pathogenesis have been reported and this work aims to better understand what is known so far on this issue.

Cutaneous immune-related adverse events to immune checkpoint inhibitors: from underlying immunological mechanisms to multi-omics prediction

The development of immune checkpoint inhibitors (ICIs) has dramatically altered the landscape of therapy for multiple malignancies, including urothelial carcinoma, non-small cell lung cancer, melanoma and gastric cancer. As part of their anti-tumor properties, ICIs can enhance susceptibility to inflammatory side effects known as immune-related adverse events (irAEs), in which the skin is one of the most commonly and rapidly affected organs. Although numerous questions still remain unanswered, multi-omics technologies have shed light into immunological mechanisms, as well as the correlation between ICI-induced activation of immune systems and the incidence of cirAE (cutaneous irAEs). Therefore, we reviewed integrated biological layers of omics studies combined with clinical data for the prediction biomarkers of cirAEs based on skin pathogenesis. Here, we provide an overview of a spectrum of dermatological irAEs, discuss the pathogenesis of this "off-tumor toxicity" during ICI treatment, and summarize recently investigated biomarkers that may have predictive value for cirAEs via multi-omics approach. Finally, we demonstrate the prognostic significance of cirAEs for immune checkpoint blockades.

Checkpoint inhibitor therapy and psoriasis: a case series

Checkpoint inhibitor therapy (CPI) has significantly improved overall survival in several cancers, including metastatic melanoma and in the adjuvant setting. Cutaneous immune-related adverse events secondary to CPI are commonly observed; however, the development of psoriasis or exacerbation of existing psoriasis has not been widely reported and management can be challenging.

What's new in the pathogeneses and triggering factors of bullous pemphigoid

Bullous pemphigoid (BP) is a subepidermal blistering disease induced by autoantibodies to type XVII collagen (COL17, also called BP180) and BP230. Previous studies using patients' samples and animal disease models elucidated the complement-dependent and complement-independent pathways of blister formation, the pathogenic roles of immune cells (T and B cells, macrophages, mast cells, neutrophils, eosinophils), and the pathogenicity of IgE autoantibodies in BP. This review introduces the recent progress on the mechanism behind the epitope-spreading phenomenon in BP, which is considered to be important to understand the chronic and intractable disease course of BP, and the pathogenicity of anti-BP230 autoantibodies, mainly focusing on studies that used active disease models. To clarify the pathogenesis of BP, the mechanism behind the breakdown of immune tolerance to BP antigens should be investigated. Recent studies using various experimental models have revealed important roles for regulatory T cells in the maintenance of self-tolerance to COL17 and BP230 as well as in the suppression of inflammation triggered by the binding of antibodies to COL17. Notably, physical stresses such as trauma, thermal burns, bone fractures, irradiation and ultraviolet exposure, some pathologic conditions such as neurological diseases and hematological malignancies, and the use of dipeptidyl peptidase-IV inhibitors and immune checkpoint inhibitors have been reported as triggering factors for BP. These factors and certain underlying conditions such as genetic background, regulatory T-cell dysfunction or aging might synergistically affect some individuals and eventually induce BP. Further studies on the breakdown of self-tolerance and on the identification of key molecules that are relevant to blister formation and inflammation may expand our understanding of BP's etiology and may lead to the development of novel therapeutic approaches.