Bullous pemphigoid, an autoantibody-mediated disease, is a novel immune-related adverse event in patients treated with anti-programmed cell death 1 antibodies

Oral and cutaneous immune-related adverse events in cancer patients: Prevalence and overall survival

OBJECTIVES

To assess the prevalence of cutaneous and oral immune-related adverse events (irAEs) in cancer patients, risk factors for its development, and overall survival (OS).

MATERIALS AND METHODS

This retrospective observational study which included 748 medical records of cancer patients who received immune checkpoint inhibitors (ICIs). Demographic and clinicopathological characteristics were collected and analyzed.

RESULTS

Most patients were male (59.4%), with stage IV cancer (65%) and received pembrolizumab (46.7%). Four hundred fourteen (55.34%) patients developed cutaneous lesions, 84 (11.2%) developed oral mucosal lesions, and 70 (9.3%) developed xerostomia. The median time for irAEs development was 11 weeks for cutaneous and oral mucosal lesions, and 21.5 weeks for xerostomia. Patients who received PD-1 + CTLA-4 had a higher risk for developing cutaneous irAEs (p = 0.001), while those who underwent ICI and concurrent chemotherapy had a higher risk (p = 0.008) for developing oral mucosal lesions. Patients who presented oral and cutaneous irAEs had better OS than those who did not present (p = 0.0001).

CONCLUSION

Cutaneous effects affected more than half of the patients, while oral effects and xerostomia were found in around 11% and 9% of patients, respectively. Concurrent chemotherapy and PD-1 + CTLA-4 were more associated with oral and cutaneous irAEs, respectively. Patients who developed such irAEs had better overall survival.

Targeting PD-L1 in cholangiocarcinoma using nanovesicle-based immunotherapy

This study demonstrates the potential of using biological nanoparticles to deliver RNA therapeutics targeting programmed death-ligand 1 (PD-L1) as a treatment strategy for cholangiocarcinoma (CCA). RNA therapeutics offer prospects for intracellular immune modulation, but effective clinical translation requires appropriate delivery strategies. Milk-derived nanovesicles were decorated with epithelial cellular adhesion molecule (EpCAM) aptamers and used to deliver PD-L1 small interfering RNA (siRNA) or Cas9 ribonucleoproteins directly to CCA cells. In vitro, nanovesicle treatments reduced PD-L1 expression in CCA cells while increasing degranulation, cytokine release, and tumor cell cytotoxicity when tumor cells were co-cultured with T cells or natural killer cells. Similarly, immunomodulation was observed in multicellular spheroids that mimicked the tumor microenvironment. Combining targeted therapeutic vesicles loaded with siRNA to PD-L1 with gemcitabine effectively reduced tumor burden in an immunocompetent mouse CCA model compared with controls. This proof-of-concept study demonstrates the potential of engineered targeted nanovesicle platforms for delivering therapeutic RNA cargoes to tumors, as well as their use in generating effective targeted immunomodulatory therapies for difficult-to-treat cancers such as CCA.

A Review of Bullous Dermatologic Adverse Events Associated with Anti-Cancer Therapy

The rapid evolution of anti-cancer therapy (including chemotherapy, targeted therapy, and immunotherapy) in recent years has led to a more favorable efficacy and safety profile for a growing cancer population, and the improvement of overall survival and reduction of morbidity for many cancers. Anti-cancer therapy improves outcomes for cancer patients; however, many classes of anti-cancer therapy have been implicated in the induction of bullous dermatologic adverse events (DAE), leading to reduced patient quality of life and in some cases discontinuation of life-prolonging or palliative therapy. Timely and effective management of adverse events is critical for reducing treatment interruptions and preserving an anti-tumor effect. Bullous DAE may be limited to the skin or have systemic involvement with greater risk of morbidity and mortality. We present the epidemiology, diagnosis, pathogenesis, and management of bullous DAE secondary to anti-cancer therapies to enable clinicians to optimize management for these patients.

Analysis of the clinical characteristics of pembrolizumab-induced bullous pemphigoid

Background

Pembrolizumab, a programmed cell death protein 1 checkpoint inhibitor, is a novel drug used to treat a variety of advanced malignancies. However, it can also result in many immune-related adverse events, with cutaneous toxicities being the most frequent. Regarding pembrolizumab-induced skin adverse reactions, bullous pemphigoid (BP) has the worst effects on quality of life. Recently, there have been more and more reports of BP incidents resulting from pembrolizumab therapy in patients with cancer. This study aimed to define the clinical characteristics, diagnosis and management of pembrolizumab-induced BP and identify potential differences between classical BP and pembrolizumab-induced BP.

Methods

Case reports, case series, and case analyses of pembrolizumab-induced BP up to 10 December 2022 were collected for retrospective analysis.

Results

Our study included 47 patients (33 males and 14 females) from 40 studies. The median age was 72 years (range 42-86 years). The median time to cutaneous toxicity was 4 months (range 0.7-28 months), and the median time to bullae formation was 7.35 months (range 0.7-32 months). The most common clinical features were tense bullae and blisters (85.11%), pruritus (72.34%), and erythema (63.83%) on the limbs and trunk. In 20 of the 22 cases tested, the serum anti-BP180 autoantibodies were positive. However, in 10 cases (91.90%, 10/11) the circulating autoantibodies of anti-BP230 were negative. 40 patients had skin biopsies and the skin biopsy revealed subepidermal bullae or blister eosinophil infiltration in 75.00% of patients with pembrolizumab-induced BP, 10.00% of patients with lymphocyte infiltration and 20.00% of patients with neutrophil infiltration. There were 20 patients (50%) with eosinophilic infiltration around the superficial dermis vessels, 8 patients (20.00%) with lymphocyte infiltration around the superficial dermis vessels, and 4 patients (10.00%) with neutrophil infiltration around the superficial dermis vessels. Direct immunofluorescence detected linear immunoglobulin G (IgG) IgG and/or complement C3 along the dermo-epidermal junction in 36 patients (94.74%) with BP. IgG positivity was detected by indirect immunofluorescence in 81.82% of patients with BP. All patients were in complete remission (95.65%,44/46) or partial remission (4.35%, 2/46) of BP, whereas 9/46 patients had a relapse or refractory. The majority of patients achieved BP remission after discontinuation of pembrolizumab with a combination of topically and systemically administered steroid treatments, or other medications. The median duration of BP remission was 2 months (range 0.3-15 months).

Conclusion

A thorough diagnosis of pembrolizumab-induced BP should be made using clinical signs, biochemical markers, histopathological and immunopathological tests. Pembrolizumab-induced BP had similar clinical characteristics to classic BP. Temporary or permanent discontinuation of pembrolizumab therapy may be required in patients with perbolizumab-induced BP depending on the severity of BP and the response to medication. Pembrolizumab-induced BP may be effectively treated using topical and systemic steroid treatments in combination with other medications (e.g., doxycycline, niacinamide, dapsone, rituximab, intravenous immunoglobulins, dupilumab, cyclophosphamide, methotrexate, mycophenolate mofetil, and infliximab). Clinicians should provide better management to patients with BP receiving pembrolizumab to prevent progression and ensure continuous cancer treatment.

A Retrospective, Single-Institution Experience of Bullous Pemphigoid as an Adverse Effect of Immune Checkpoint Inhibitors

Simple Summary

This article investigates the cutaneous adverse immune effects induced by immune checkpoint inhibitors. These drugs target proteins expressed on cancer cells that aid in the avoidance of immune system detection and destruction. Immune checkpoint inhibitors inadvertently cause other immune-mediated adverse effects. Cutaneous toxicities are the commonest adverse effect from immunotherapy; furthermore, they are usually developed early in the course of treatment. A rare and severe cutaneous adverse event is Bullous Pemphigoid. This article investigates the average and median onset of these drug toxicities, as well as treatments. We found these side effects to be negatively skewed, indicating most cases occur several months into treatment.

Abstract

Immune checkpoint inhibitors are a class of cancer treatment drugs that stimulate the immune system’s ability to fight tumor cells. These drugs are monoclonal antibodies targeting im-mune-inhibiting proteins on cancer cells, such as CTLA-4 and PD-1/PD-L1. Immune checkpoint inhibitors cause many immune-related adverse events. Cutaneous toxicities are of the most common adverse effects and occur with a range of severity. Bullous Pemphigoid is a rare adverse event with a high impact on quality of life that may occur after immune checkpoint inhibitor treatment. In this article, we investigate current research on immune checkpoint inhibitors, cutaneous adverse events, and common presentations and treatments, with a specific focus on Bullous Pemphigoid, its characteristics, onset timing, and treatment. Significant findings include a negative skew in the onset of presentation. Furthermore, we describe exclusive cases.

Hemidesmosomal Reactivity and Treatment Recommendations in Immune Checkpoint Inhibitor-Induced Bullous Pemphigoid—A Retrospective, Monocentric Study

Immune checkpoint inhibitors (ICI) induce T-cell-mediated antitumour responses. While ICI were initially successfully applied in metastasized melanoma, they are now approved for several tumour entities. Numerous autoimmune disorders have been reported to occur as adverse events of the treatment, among them bullous pemphigoid (BP), with less than 1% of the patients experiencing ICI-induced BP. This number is higher than the estimated prevalence of autoimmune bullous diseases in the general population of Germany, which lies around 0.05%. We here describe our cohort of eight patients, who developed a bullous pemphigoid under or shortly after ICI treatment. Half of them had a severe subtype (as shown by BPDAI >57) and showed a median onset of ICI-BP after 10 months of ICI initiation. Six patients had a palmar and/or plantar involvement, while oral involvement occurred in one case. All patients had linear epidermal IgG depositions in split skin in the indirect immunofluorescence. In four out of five biopsies available for direct immunofluorescence, linear IgG and C3 depositions were detected at the basement membrane, while one patient showed linear IgM staining. Moderate to high levels of FLBP180 autoantibodies were found in seven of eight cases. The disease can still be active after ICI discontinuation, while rituximab might be required for remission. Finally, four tumour samples were stained histochemically for collagen XVII (BP180), but no enhanced expression was found.

Association of Bullous Pemphigoid With Immune Checkpoint Inhibitor Therapy in Patients With Cancer: A Systematic Review

Importance

There is limited information on immune checkpoint inhibitor-induced bullous pemphigoid (ICI-BP) in patients with cancer, with most existing studies being case reports or small case series from a single institution. Prior review attempts have not approached the literature in a systematic manner and have focused only on ICI-BP secondary to anti-programmed cell death 1 (PD-1) or programmed cell death ligand 1 (PD-L1) therapy. The current knowledge base of all aspects of ICI-BP is limited.

Objective

To characterize the risk factors, clinical presentation, diagnostic findings, treatments, and outcomes of ICI-BP in patients with cancer as reported in the current literature.

Evidence Review

A systematic review was performed using PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Articles reporting data on individual patients who met preestablished inclusion criteria were selected, and a predefined set of data was abstracted. When possible, study results were quantitatively combined.

Findings

In total, 70 studies reporting data on 127 individual patients undergoing ICI therapy for cancer (median [IQR] age, 71 [64-77] years; 27 women [21.3%]) were included. In pooled analyses, patients ranged in age from 35 to 90 years. Immune checkpoint inhibitor-induced bullous pemphigoid often occurred during the course of anti-PD-1, PD-L1, or cytotoxic T lymphocyte-associated antigen 4 therapy but was also found to develop up to several months after treatment cessation. Prodromal symptoms, such as pruritus or nonspecific skin eruptions, were found in approximately half of the patient population. Histopathologic or serologic testing, when undertaken, was a helpful adjunct in establishing diagnosis. Treatment with immunotherapy was discontinued after ICI-BP development in most patients. The most common treatments were systemic and topical corticosteroids. Steroid-sparing therapies, such as antibiotics and other systemic immunomodulators, were also used as adjuvant treatment modalities. Biologic and targeted agents, used predominantly in cases refractory to treatment with corticosteroids, were associated with marked symptomatic improvement in most patients.

Conclusions and Relevance

The results of this systematic review suggest that ICI-BP often poses a therapeutic challenge for patients with cancer who are receiving immunotherapy. Further research on the early recognition, diagnosis, and use of targeted treatment modalities will be essential in developing more personalized treatment options for affected patients while minimizing morbidity and mortality.

Bullous Pemphigoid in Patients Receiving Immune-Checkpoint Inhibitors and Psoriatic Patients—Focus on Clinical and Histopathological Variation

Background: The most common autoimmune blistering disease, bullous pemphigoid (BP), shows an increased prevalence in psoriatic patients and oncologic patients undergoing immune-checkpoint blockade (ICB). Even though the same autoantigens (BP180/BP230) are detectable, it remains obscure whether clinical or histopathological differences exist between these different groups of BP patients. In this study, we strived to analyze this matter based on own data and previously published reports. Methods: We performed an institutional chart review from 2010–2020 to identify BP patients with psoriasis (n = 6) or underlying ICB (n = 4) and matched them with idiopathic cases of BP (n = 33). We compared clinical characteristics, subtypes, and dermatopathological determinants (e.g., tissue eosinophilia/neutrophilia, papillary edema, lymphocytic infiltration) among the groups. Results: ICB-associated BP affects men more often and might show mucosal involvement more frequently. We found no statistically significant dermatopathological differences among the groups. Conclusions: Clinicians should be aware of an increased risk of BP in patients with psoriasis and oncologic patients receiving ICB; atypical pruritic skin lesions should prompt a workup including a skin biopsy for histopathology and direct immunofluorescence in these patients. Larger studies might be necessary to detect slight dermatopathological variation.

Oral Immune-Related Adverse Events Caused by Immune Checkpoint Inhibitors: Salivary Gland Dysfunction and Mucosal Diseases

Conventional chemotherapy and targeted therapies have limited efficacy against advanced head and neck squamous cell carcinoma (HNSCC). The immune checkpoint inhibitors (ICIs) such as antibodies against CTLA-4, PD-1, and PD-L1 interrupt the co-inhibitory pathway of T cells and enhance the ability of CD8+ T cells to destroy tumors. Even in advanced HNSCC patients with recurrent diseases and distant metastasis, ICI therapy shows efficiency and become an effective alternative to conventional chemotherapy. However, as this therapy releases the immune tolerance state, cytotoxic CD8+ T cells can also attack organs and tissues expressing self-antigens that cross-react with tumor antigens and induce immune-related adverse events (irAEs). When patients with HNSCC are treated with ICIs, autoimmune diseases occur in multiple organs including the skin, digestive tract, endocrine system, liver, and respiratory tract. Treatment of various malignancies, including HNSCC, with ICIs may result in the appearance of oral irAEs. In the oral cavity, an oral lichenoid reaction (OLR) and pemphigoid develop. Sicca syndrome also occurs in association with ICIs, affecting the salivary glands to induce xerostomia. It is necessary to elucidate the pathogenic mechanisms of these intractable diseases that are not seen with conventional therapy. Early diagnosis and appropriate approaches to irAEs are needed for efficient treatment of advanced HNSCC by ICIs.

[What should specialist in internal medicine be aware of in patients treated with biologics? : Infections and autoimmune phenomena]

Biologics that influence the immune system play a crucial role in the treatment of autoimmune and malignant diseases. Overall these drugs have revolutionized treatment as they demonstrate high efficacy and a relatively low amount of side effects. This leads to longer treatment of patients with a high quality of life. Side effects, especially longer-term side effects, become ever more important as patients are simultaneously seen by different physicians due to comorbidities. Infections, mainly of the upper airway or urogenital tract, represent the main side effect of immunosuppressive biologics, but atypical infections by fungi or mycobacteria may also occur. Biologics that enhance the immune response such as checkpoint inhibitors lead to autoimmune phenomena necessitating the interruption of treatment or immunosuppressive treatment.

Management of Cutaneous Immune-Related Adverse Events in Patients With Cancer Treated With Immune Checkpoint Inhibitors: A Systematic Review

Importance

There exists a paucity of literature that summarizes the effective management of cutaneous immune-related adverse events (cirAEs) in patients with cancer who are receiving immune checkpoint inhibitors (ICIs). Most published articles are small case series from a single institution. To our knowledge, the spectrum of possible treatments has not been systematically reviewed to highlight the breadth of options when caring for patients with cirAEs.

Objective

To further characterize the development of subtypes of cirAEs in patients with cancer treated with ICIs and provide recommendations on optimal treatment regimens based on the current literature.

Evidence Review

A search was performed in PubMed, Embase European, Web of Science, and Google Scholar on June 26, 2020, according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, limited to the years 2010 to 2020. Articles that met predetermined inclusion criteria (published between January 1, 2010, and June 1, 2020; written in the English language; and original articles, brief reports, case reports, and research letters that reported primarily on cirAE management) were selected, and data were abstracted. Articles that met the scope of the review were also added from reference lists. When possible, the results of studies that addressed a similar question were combined quantitatively.

Findings

In total, 138 studies (87 from the aforementioned literature search and 51 additional studies pulled from the reference lists of included articles) were included that reported on 879 cirAEs. The subtypes of cirAEs included maculopapular, pruritus, lichenoid, immunobullous, psoriasiform, granulomatous, erythema multiforme or Stevens Johnson Syndrome, drug rash with eosinophilia and systemic symptoms, connective tissue disease, hair, oral, and miscellaneous. Treatments for cirAEs included a combination of topical corticosteroids, systemic corticosteroids, steroid-sparing agents, and discontinuation or cessation of immunotherapy.

Conclusions and Relevance

This systematic review found that treatment with ICIs was associated with many types of skin toxic effects, each with unique treatment options beyond current published guidelines. Further research into key differences between subtypes is critical to improve the care provided to patients with cancer.

A tumor extracellular pH-sensitive PD-L1 binding peptide nanoparticle for chemo-immunotherapy of cancer

Chemo-immunotherapy is a promising model for the combination treatment of cancer. Many solid tumors overexpress programmed cell death ligand (PD-L1) for immune suppression. In this study, a PD-L1 binding peptide conjugate (DCS) nanoparticle with tumor extracellular pH-responsiveness was developed for efficient chemo-immunotherapy of colon cancer. A hydrophilic D-type polypeptide (D-PPA) and two hydrophobic stearyl chains were linked with a pH-sensitive linker to obtain amphiphilic DCS, which could self-assemble into nanoparticles (NPs). Anticancer agent doxorubicin (DOX) was loaded to obtain DOX@DCS NPs, which could accumulate at the tumor site by enhanced permeability and retention effect and release D-PPA at tumor extracellular pH. The release of D-PPA could not only lead to instability and aggregation of NPs for enhanced tumor retention but also block PD-1/PD-L1 to avoid immune escape and elicit enhanced immune response. In addition, DOX could induce immunogenic cell death (ICD) of cancer cells and promote anti-tumor immune response with the combination of PD-1/PD-L1 blocking. DOX@DCS showed efficient inhibition of CT26 tumors and induced immune response both in vitro and in vivo. Overall, our study reported a facile yet robust nanosystem based on an immune blocking peptide and a chemotherapeutic ICD inducer for efficient chemo-immunotherapy of cancer.

A Late Dermatologic Presentation of Bullous Pemphigoid Induced by Anti-PD-1 Therapy and Associated with Unexplained Neurological Disorder

Immunotherapy has become the standard of care for various cancer types. The widespread use of immune checkpoints inhibitors confronts us with a whole range of novel immune-related adverse events. Skin toxicity is one of the most frequent adverse events. In this article, we report a case of anti-PD-1 induced late bullous pemphigoid (BP) with mucosal erosions and associated with a troublesome neurological disorder of undetermined origin in a patient with metastatic melanoma. Skin biopsy was essential to make the diagnosis and rapid initiation of systemic prednisolone played a role in favorable clinical outcome of BP. We will discuss the difficulty of early diagnosis of BP, its unusual association with neurological disorders, and the specific management of this particular dermatological entity.

Discovery of a novel, potent and selective small-molecule inhibitor of PD-1/PD-L1 interaction with robust in vivo anti-tumour efficacy

BACKGROUND AND PURPOSE

PD-1/PD-L1 antibodies have achieved great success in clinical treatment. However, monoclonal antibody drugs also have challenges, such as high manufacturing costs, poor diffusion, low oral bioavailability and limited penetration into tumour tissue. The development of small-molecule inhibitors of PD-1/PD-L1 interaction represents a promising perspective to overcome the above challenges in cancer immunotherapy.

EXPERIMENTAL APPROACH

We explored structural activity relationships and used biochemical assays to generate a lead compound (ZE132). CD8+ T-cells killing assay and Ifng expression assay were used to verify the in vitro cellular activity of ZE132. Off-target study was performed to verify the selectivity. Syngeneic mouse models were used to verify the in vivo activity of ZE132 in tumour immune microenvironment (TIME). We also performed pharmacokinetics profiling in mice and The Cancer Genome Atlas database analysis.

KEY RESULTS

ZE132 can effectively inhibit the PD-1/PD-L1 interactions in vitro, and it has a potent affinity to PD-L1. ZE132 shows robust anti-tumour effects in vivo, better than anti-PD-1 antibody. In the analysis of TIME, we found that ZE132 treatment promotes cytotoxic T-cell tumour infiltration and induces IL-2 expression. In addition, ZE132 elicits strong inhibitory effects on the mRNA expression of TGF-β, which may serve as a potential biomarker to predict responsiveness to PD-1/PD-L1 immunotherapies.

CONCLUSION AND IMPLICATIONS

We identified a new lead compound ZE132 targeting PD-1/PD-L1 interactions, not only showing favourable drug-like properties in vitro and in vivo but also showing the advantage of overcoming the barrier of TIME compared to anti-PD-1 antibody.

Oral Manifestations in Melanoma Patients Treated with Target or Immunomodulatory Therapies

BACKGROUND

BRAF (v-raf murine sarcoma viral oncogene homolog B1) and MEK (mitogen activated protein kinase) inhibitors, as well as immunotherapy against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1), have shown good results in improving the disease-free survival of patients with metastatic melanoma (MM). The aim of this review is to summarize the main oral adverse events (oAEs) occurring in patients undergoing target or immunotherapy. We proposed two separate sections: oAEs during the treatment with (1) target therapies with BRAF and MEK inhibitors and tyrosine kinase inhibitors (gingival hyperplasia, pigmentation disorders, squamo-proliferative lesions) and (2) immunotherapies with CTLA-4 or PD1 inhibitors (lichenoid reactions, immuno-bullous reactions, xerostomia and other reactions). Adverse events frequently include oAEs, although these are often misdiagnosed and under-reported. Indeed, the oral cavity is not routinely evaluated during clinical practice. The symptomatology related to oAEs is significant since it may represent the first manifestation of a severe systemic reaction, possibly leading to difficulties in nutrition with a consequent impact on patients' quality of life. A careful examination of the oral cavity is recommended during the evaluation of oncologic patients in order to promptly detect the onset of new manifestations.

Recent advances in the development of protein-protein interactions modulators: mechanisms and clinical trials

Protein-protein interactions (PPIs) have pivotal roles in life processes. The studies showed that aberrant PPIs are associated with various diseases, including cancer, infectious diseases, and neurodegenerative diseases. Therefore, targeting PPIs is a direction in treating diseases and an essential strategy for the development of new drugs. In the past few decades, the modulation of PPIs has been recognized as one of the most challenging drug discovery tasks. In recent years, some PPIs modulators have entered clinical studies, some of which been approved for marketing, indicating that the modulators targeting PPIs have broad prospects. Here, we summarize the recent advances in PPIs modulators, including small molecules, peptides, and antibodies, hoping to provide some guidance to the design of novel drugs targeting PPIs in the future.

Bullous pemphigoid in elderly woman affected by non-small cell lung cancer treated with pembrolizumab: A case report and review of literature

INTRODUCTION

Immunotherapy has changed the management of patients with various types of malignancies (melanoma, renal, lung, and bladder cancers) but immune checkpoint inhibitors may be associated with several adverse events. Up to 20% of patients treated with immune checkpoint inhibitors may develop dermatological immune-related adverse events, mostly rashes and pruritus but rarely even bullous pemphigoid.

CASE REPORT

We report a case of an elderly patient with advanced non-small cell lung cancer in therapy with pembrolizumab, 200 mg/body every three weeks. After 26 cycles of therapy, the patient developed widespread itching and then after 28 cycles she developed strained blisters filled with serous fluids on predominantly erythematous skin with suspicious of bullous pemphigoid.Management and outcome: Skin biopsy confirms bullous pemphigoid, so we decided to permanently discontinue therapy with pembrolizumab and the patient is currently on therapy with doxycycline, nicotinamide, and clobetasol propionate with good regression of symptoms and cutaneous lesions.

DISCUSSION

In the literature, the first case of bullous pemphigoid induced by pembrolizumab has been described in 2015. On Pubmed, from 2015 to date, we have found 19 cases of bullous pemphigoid during pembrolizumab therapy but only three of them are related to non-small cell lung cancer, adding our patient we reach a total of 20 cases. It could be interesting to investigate if there is a specific relationship between the appearance of itching and the development of bullous pemphigoid.

Cutaneous Immune-Related Adverse Events (irAEs) to Immune Checkpoint Inhibitors: A Dermatology Perspective on Management [Formula: see text]

Immune checkpoint inhibitors have proven to be efficacious for a broad spectrum of solid organ malignancies. These monoclonal antibodies lead to cytotoxic T-cell activation and subsequent elimination of cancer cells. However, they can also lead to immune intolerance and immune-related adverse event (irAEs) that are new and specific to these therapies. Cutaneous irAEs are the most common, arising in up to 34% of patients on PD-1 inhibitors and 43% to 45% on CTLA-4 inhibitors. The most common skin manifestations include maculopapular eruption, pruritus, and vitiligo-like lesions. A grading system has been proposed, which guides management of cutaneous manifestations based on the percent body surface area (BSA) involved. Cutaneous irAEs may prompt clinicians to reduce drug doses, add systemic steroids to the regiment, and/or discontinue lifesaving immunotherapy. Thus, the goal is for early identification and concurrent management to minimize treatment interruptions. We emphasize here that the severity of the reaction should not be graded based on BSA involvement alone, but rather on the nature of the primary cutaneous pathology. For instance, maculopapular eruptions rarely affect <30% BSA and can often be managed conservatively with skin-directed therapies, while Stevens-Johnson syndrome (SJS) affecting even 5% BSA should be managed aggressively and the immunotherapy should be discontinued at once. There is limited literature available on the management of the cutaneous irAEs and most studies present anecdotal evidence. We review the management strategies and provide recommendations for psoriatic, immunobullous, maculopapular, lichenoid, acantholytic eruptions, vitiligo, alopecias, vasculitides, SJS/toxic epidermal necrolysis, and other related skin toxicities.

Fixed drug eruptions, bullous drug eruptions, and lichenoid drug eruptions

Drug reactions are among the most common reasons for inpatient dermatology consultation. These reactions are important to identify because discontinuation of the offending agent may lead to disease remission. With the rising use of immunomodulatory and targeted therapeutics in cancer care and the increased incidence in associated reactions to these drugs, the need for accurate identification and treatment of such eruptions has led to the development of the "oncodermatology" subspecialty of dermatology. Immunobullous drug reactions are a dermatologic urgency, with patients often losing a significant proportion of their epithelial barrier; early diagnosis is critical in these cases to prevent complications and worsening disease. Lichenoid drug reactions have myriad causes and can take several months to occur, often leading to difficulties identifying the offending drug. Fixed drug eruptions can often mimic other systemic eruptions, such as immunobullous disease and Stevens-Johnson syndrome, and must be differentiated from them for effective therapy to be initiated. We review the clinical features, pathogenesis, and treatment of immunobullous, fixed, and lichenoid drug reactions with attention to key clinical features and differential diagnosis.

Small Molecular Immune Modulators as Anticancer Agents

After decades of intense effort, immune checkpoint inhibitors have been conclusively demonstrated to be effective in cancer treatments and thus are revolutionizing the concepts in the treatment of cancers. Immuno-oncology has arrived and will play a key role in cancer treatment in the foreseeable future. However, efforts to find novel methods to improve the immune response to cancer have not ceased. Small-molecule approaches offer inherent advantages over biologic immunotherapies since they can cross cell membranes, penetrate into tumor tissue and tumor microenvironment more easily, and are amenable to be finely controlled than biological agents, which may help reduce immune-related adverse events seen with biologic therapies and provide more flexibility for the combination use with other therapies and superior clinical benefit. On the one hand, small-molecule therapies can modulate the immune response to cancer by restoring the antitumor immunity, promoting more effective cytotoxic lymphocyte responses, and regulating tumor microenvironment, either directly or epigenetically. On the other hand, the combination of different mechanisms of small molecules with antibodies and other biologics demonstrated admirable synergistic effect in clinical settings for cancer treatment and may expand antibodies' usefulness for broader clinical applications. This chapter provides an overview of small-molecule immunotherapeutic approaches either as monotherapy or in combination for the treatment of cancer.

Cutaneous adverse reactions to anti-PD-1 treatment-A systematic review

The use of the humanized monoclonal anti-programmed cell death 1 antibodies pembrolizumab and nivolumab as potent anticancer therapies is rapidly increasing. However, since their approval, numerous cases of cutaneous reactions have been reported. Cutaneous adverse reactions to these agents have yet to be fully characterized and range from nonspecific eruptions to recognizable skin manifestations, which may be localized and vary from mild to life threatening. This systematic review article provides an overview of the various adverse cutaneous reactions to pembrolizumab and nivolumab therapy and offers suggestions for their management.

Cutaneous Adverse Events of Anti-PD-1 Therapy and BRAF Inhibitors

OPINION STATEMENT

The treatment of advanced melanoma has undergone a dramatic transformation over the last decade with the advent of targeted and immunomodulatory therapies. This transition from cytotoxic chemotherapy has yielded improvements in both survival and quality of life; yet despite their therapeutic advantages, these treatments have been associated with a diverse range of cutaneous adverse events (AEs). These range from relatively benign eczematous conditions to more severe inflammatory and bullous disorders, and can include induction of second malignancies. AEs can result in serious morbidity and risk of mortality if not recognised and managed early. As a consequence of their novelty, and rapid uptake, these agents have been subject to intense scrutiny and there is a general understanding that cutaneous AEs should be anticipated in treatment plans. Dermatologists should be integrated into management teams to assist in the development of treatment protocols for anticipated common AEs and to provide expert management of more severe, rare or unusual AEs. Our experience has shown a reduction in treatment interruptions, more rapid recognition of unusual AEs and improved management pathways for patients suffering cutaneous AEs.

Adverse effects of immune-checkpoint inhibitors: epidemiology, management and surveillance

Immune-checkpoint inhibitors (ICIs), including anti-cytotoxic T lymphocyte antigen 4 (CTLA-4), anti-programmed cell death 1 (PD-1) and anti-programmed cell death 1 ligand 1 (PD-L1) antibodies, are arguably the most important development in cancer therapy over the past decade. The indications for these agents continue to expand across malignancies and disease settings, thus reshaping many of the previous standard-of-care approaches and bringing new hope to patients. One of the costs of these advances is the emergence of a new spectrum of immune-related adverse events (irAEs), which are often distinctly different from the classical chemotherapy-related toxicities. Owing to the growing use of ICIs in oncology, clinicians will increasingly be confronted with common but also rare irAEs; hence, awareness needs to be raised regarding the clinical presentation, diagnosis and management of these toxicities. In this Review, we provide an overview of the various types of irAEs that have emerged to date. We discuss the epidemiology of these events and their kinetics, risk factors, subtypes and pathophysiology, as well as new insights regarding screening and surveillance strategies. We also highlight the most important aspects of the management of irAEs.

Melanoma and Vitiligo: In Good Company

Cutaneous melanoma represents the most aggressive form of skin cancer, whereas vitiligo is an autoimmune disorder that leads to progressive destruction of skin melanocytes. However, vitiligo has been associated with cutaneous melanoma since the 1970s. Most of the antigens recognized by the immune system are expressed by both melanoma cells and normal melanocytes, explaining why the autoimmune response against melanocytes that led to vitiligo could be also present in melanoma patients. Leukoderma has been also observed as a side effect of melanoma immunotherapy and has always been associated with a favorable prognosis. In this review, we discuss several characteristics of the immune system responses shared by melanoma and vitiligo patients, as well as the significance of occurrence of leukoderma during immunotherapy, with special attention to check-point inhibitors.

Bullous Pemphigoid-like Skin Lesions and Overt Eosinophilia in a Patient With Melanoma Treated With Nivolumab: Case Report and Review of the Literature

The widespread use of immune checkpoint inhibitors has shed light to several unusual immune-related adverse effects of the drugs. Severe cutaneous adverse reactions are generally rare with anti-PD1 agents. We present in this paper the case of a 48-year-old patient with melanoma who developed bullous pemphigoid-like skin lesions along with fever, arthralgia and overt eosinophilia following adjuvant treatment with nivolumab. The condition was successfully treated with corticosteroids and a rechallenge with another anti-PD1 agent did not lead to recurrence of the skin lesions. We also reviewed the literature on the epidemiologic, clinical, and histopathologic characteristics of bullous pemphigoid as well as on the treatment and prognosis of this dermatologic condition in patients with melanoma or other malignancies under treatment with immune checkpoint inhibitors.

Cutaneous lupus associated with pembrolizumab therapy for advanced melanoma: a report of three cases

Checkpoint blockade immunotherapy has revolutionized the treatment of advanced melanoma, with impressive survival benefits attained through upregulation of the anticancer immune response. Blockade of regulatory checkpoint molecules can, however, also result in aberrant immune activation leading to undesirable inflammation and autoimmunity. Although many genetic determinants have been described in patients with primary autoimmune diseases, it is uncertain whether patients developing autoimmune skin disease as an adverse effect of anti-PD-1 therapy share the same genetic risks. Furthermore, it is also unclear whether treatment with these agents can result in the unveiling of underlying 'silent' autoimmunity resulting in chronic inflammatory disease. We report three cases of cutaneous lupus associated with pembrolizumab therapy for advanced melanoma. One patient had a previous diagnosis of histologically proven discoid lupus erythematosus, well-controlled without treatment for over 2 years, which flared on first exposure to pembrolizumab. The remaining two patients had no previous history of autoimmune disease; both developed cutaneous eruptions, histologically and immunohistologically, in keeping with subacute cutaneous lupus following treatment with pembrolizumab. Our report bolsters what is currently an exceedingly small body of evidence documenting the development of cutaneous lupus in the setting of pembrolizumab therapy. Our third case specifically documents an otherwise unreported severe reflare of previously diagnosed, quiescent discoid lupus erythematosus in the setting of pembrolizumab, vividly highlighting the potential for autoimmune and specifically, lupus reactivation in the setting of anti-PD-1 therapy.

Delayed immune-related events (DIRE) after discontinuation of immunotherapy: diagnostic hazard of autoimmunity at a distance

BACKGROUND

The risk of delayed autoimmunity occurring months or years after discontinuation of immunotherapy is frequently asserted in the literature. However, specific cases were rarely described until 2018, when a wave of reports surfaced. With expanding I-O indications in the adjuvant/neoadjuvant curative setting, growing numbers of patients will receive limited courses of immunotherapy before entering routine surveillance. In this context, under-recognition of DIRE could pose a growing clinical hazard.

METHODS

The aim of this study was to characterize DIRE through identification of existing reports of delayed post-treatment irAE in cancer patients treated with immunotherapy. We performed a PubMed literature review from 2008 through 2018 to determine the median data safety reporting window from existing I-O clinical trials, which we then applied to define the DIRE cutoff, and collated all qualifying reports over the same time span. DIRE was defined as new immune-related adverse events (irAE) manifesting ≥90 days after discontinuation of immunotherapy.

RESULTS

Median duration of I-O clinical trials data safety reporting was 90 days (82% ≤ 90 days). DIRE cutoff was thus set as ≥90 days post-immunotherapy. We identified 23 qualifying cases; 21 by literature review and 2 from our institution. Median off-treatment interval to DIRE was 6 months (range: 3 to 28). Median cumulative immunotherapy exposure was 4 doses (range: 3 to 42). Involvement included endocrine, neurologic, GI, pulmonary, cardiac, rheumatologic and dermatologic irAE.

CONCLUSIONS

As immunotherapy indications expand into the curative setting, often with brief exposure and potentially sequenced with multimodality treatments, it will be necessary to recognize an emerging diagnostic complex, which we have termed delayed immune-related events (DIRE). Clinical vigilance has the potential to reduce morbidity from diagnostic delay, as irAE are generally manageable with prompt initiation of treatment - or from misdiagnosis - as misattribution can lead to unnecessary or harmful interventions as we describe. DIRE should therefore figure prominently in the differential diagnosis of patients presenting with illnesses of unclear etiology, irrespective of intervening treatments or interval post-immunotherapy, both of which can confound diagnosis. Increased recognition will rest on delineation of DIRE as a clinical diagnostic entity.

Anti-programmed cell death-1 therapy-associated bullous disorders: a systematic review of the literature

Bullous disorders are rare adverse events associated with anti-programmed cell death-1 (anti-PD1) therapy. This paper presents two new cases of bullous disorders under anti-PD1 therapy and systematically reviewed the literature to foster a better understanding of the presentation and pathogenesis of bullous disorders under anti-PD1. A systematic review of the literature was completed using MEDLINE, Embase, PubMed and LILACS databases. We identified 29 cases of bullous disorders under anti-PD1 therapy, including our two new cases. This includes 18 cases of bullous pemphigoid (BP), five cases of toxic epidermal necrolysis (TEN)/Stevens-Johnson syndrome (SJS) spectrum, one case of erythema multiforme (EM), four cases of bullous lichenoid reactions and one case of vesiculobullous eczema. In BP, blistering occurred by a median of 23 weeks after anti-PD1 therapy initiation and is often preceded by a prodrome, which lasts for a median of 9.5 weeks. Limbs and trunk were the most frequently involved body sites. Most cases (76%) achieved remission. In TEN/SJS/EM, blistering was usually preceded by a prodrome of interface dermatitis that lasted for a median of 1.5 weeks. Most cases (80%) died from either TEN/SJS or disease progression. Bullous disorders under anti-PD1 may be classified clinically as BP, SJS/TEN/EM, bullous lichenoid reactions and vesiculobullous eczema and histologically by intraepidermal splitting and subepidermal splitting. BP is usually preceded by a pruritic eruption and has a relatively good prognosis. SJS/TEN is usually preceded by a maculopapular eruption and has a very poor prognosis.

Cutaneous Side Effects of Targeted Therapy and Immunotherapy for Advanced Melanoma

Melanoma is one of the most fatal cancers, and its incidence is increasing worldwide. Thanks to the better understanding of the molecular mechanisms involved in the pathogenesis of melanoma, recently new targeted agents have been developed. In this article, we review the current state of knowledge of clinical presentation, mechanisms, and management of the most common cutaneous side effects observed during treatment with targeted and immunological therapies approved for advanced melanoma. We include discussion of BRAF/MEK inhibitors and immune-checkpoint inhibitors, notably CTLA-4 and PD-1 inhibitors.

Clinical management of cutaneous adverse events in patients on targeted anticancer therapies and immunotherapies: a national consensus statement by the Spanish Academy of Dermatology and Venereology and the Spanish Society of Medical Oncology

Progress in the understanding of many tumors has enabled the development of new therapies, such as those targeted at specific molecules involved in cell growth (targeted therapies) or intended to modulate the immune system (immunotherapy). However, along with the clinical benefit provided by these new treatments, new adverse effects have also appeared. Dermatological toxicities such as papulopustular eruptions, xerosis, and pruritus are common with EGFR inhibitors. Other adverse effects have also been described with PDGFR, BCR-ABL, and MAPK tyrosine kinase inhibitors, antiangiogenic drugs, and inhibitors at immune checkpoints such as CTLA-4 and PD-1/PD-L1. Onset of these adverse effects often causes dose reductions and/or delays in administering the prescribed therapy, which can affect patient survival and quality of life. It is, therefore, important to prevent the occurrence of these adverse effects, or to treat unavoidable ones as soon as possible. This requires cooperation between medical oncologists and dermatologists. This article reviews the various dermatological toxicities associated with targeted therapies and immunotherapies, along with their diagnosis and therapeutic management.

Bullous pemphigoid associated with ipilimumab therapy for advanced metastatic melanoma

Immunotherapy is now being routinely used in the management of many cancers. It is therefore vital that all clinicians are aware of the diverse array of cutaneous manifestations that can result from their use, which can vary from mild to life threatening.

A Case of Nivolumab-Induced Bullous Pemphigoid: Review of Dermatologic Toxicity Associated with Programmed Cell Death Protein-1/Programmed Death Ligand-1 Inhibitors and Recommendations for Diagnosis and Management

Immunotherapy has emerged as a highly effective treatment for numerous cancers. Use of checkpoint inhibitors against various molecules including programmed cell death protein-1 (PD-1), programmed death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 have become widespread in clinical practice. Compared with conventional chemotherapy, immunotherapy is associated with a unique set of immune reactions known collectively as immune-related adverse events (irAEs). Of known irAEs, cutaneous toxicity is among the most frequently observed in patients treated with immunotherapy. Although often mild, dermatologic toxicity can occasionally be high grade and potentially life-threatening. In this article, we report a case of PD-1 inhibitor-induced bullous pemphigoid-a serious adverse event that has been increasingly observed with use of PD-1/PD-L1 inhibitors. We will also review diagnosis and management of low-grade cutaneous irAEs and bullous disease with checkpoint inhibitors.

KEY POINTS

PD-1/PD-L1 inhibitor-induced bullous pemphigoid (BP) is a rare but potentially serious dermatologic toxicity associated with checkpoint inhibitorsIn patients with pruritus or rash that is refractory to topical steroids, physicians should have a greater index of suspicion for higher-grade cutaneous immune-related adverse events.There is no standardized treatment algorithm for management of PD-1/PD-L1 inhibitor-induced BP, but patients frequently require topical and systemic steroids.

Mucous Membrane Pemphigoid, Bullous Pemphigoid, and Anti-programmed Death-1/ Programmed Death-Ligand 1: A Case Report of an Elderly Woman With Mucous Membrane Pemphigoid Developing After Pembrolizumab Therapy for Metastatic Melanoma and Review of the Literature

An 83-year-old patient developed erosions and a blister of the gingival mucous membrane, 6 months after discontinuation of the anti-programmed death-1 (anti PD-1) pembrolizumab therapy administered for 10 months for a metastatic melanoma. A diagnosis of mild mucous membrane pemphigoid (MMP) was made. Complete remission of MMP was rapidly obtained with minimal therapy (doxycycline). MMP remained in complete remission after a 3-month follow-up since discontinuation of the doxycycline therapy and no evidence of relapse of the melanoma was observed after a 14-month follow-up since discontinuation of the pembrolizumab therapy. The widespread use of anti PD-1 and anti-programmed death-ligand-1 (PD-L1) in several malignancies reveals new adverse events. MMP describes a group of chronic, inflammatory, mucous membrane-predominant, subepithelial auto-immune blistering diseases. It is clinically distinct from bullous pemphigoid another autoimmune blistering disease but shares some immunological similarities with it. Twenty-nine cases of bullous pemphigoid associated with anti PD-1/PD-L1 have been reported in the literature and one of MMP. Here, we described the case of a MMP developed after pembrolizumab and discussed the accountability of anti PD-1/PD-L1 in our case and the previous reported bullous pemphigoid and MMP cases using the Begaud system scoring.

Bullous Pemphigoid as an Adverse Reaction to Pembrolizumab: Two Case Reports

Checkpoint inhibitors are novel and promising treatment options for different types of cancer. Programmed cell death 1 (PD-1) inhibitors, such as pembrolizumab, have been shown to significantly raise the survival rates of disseminated malignant melanoma (MM). Autoimmune adverse reactions are very common in checkpoint inhibitors. We present 2 cases of bullous pemphigoid, as adverse reactions to pembrolizumab-treated MM.

Cutaneous toxicities of new treatments for melanoma

New drugs against advanced melanoma have emerged during last decade. Target therapy and immunotherapy have changed the management of patients with metastatic disease. Along with its generalized use, drug toxicities have appeared and the skin is the target organ of a significant part of them. This revision summarizes the most common side effects and consensus management to improve the compliance of therapies and patients' quality of life. Among the BRAF inhibitors, main cutaneous side effects are photosensitivity, plantar hyperkeratosis, and the appearance of verrucal keratosis or squamous cell carcinoma. Special attention must be paid to the development of new primary melanomas or changes on nevi during BRAF inhibitor therapy. The most common cutaneous side effects of immunotherapy are rash, pruritus, and vitiligo. It remains controversial the possible role of these toxicities as markers of response to therapy.

A review of bullous pemphigoid associated with PD-1 and PD-L1 inhibitors

BACKGROUND

Dermatologic toxicity represents a substantial portion of all immune-related adverse events (irAEs) associated with PD-1/PD-L1 inhibitors. Bullous pemphigoid (BP) is a rare cutaneous side effect of these medications, which can initially be clinically indistinguishable from other, low-grade cutaneous toxicity.

OBJECTIVE

To better characterize the clinical features of BP associated with PD-1/PD-L1 inhibitors, evaluate the efficacy of various treatment regimens, determine the frequency of prodromal pruritus, and assess whether immunological diagnostic studies for BP are warranted in patients treated with checkpoint inhibitors who develop intractable pruritus.

METHODS

A comprehensive review of the English-language medical literature was performed using key terms. Papers published on any date and from all origins were considered. Fourteen publications, containing 21 patient cases, were selected independently by two reviewers and deemed relevant to the present publication.

RESULTS

Pruritus was a prominent feature of the majority (12/21) of cases and preceded or occurred concurrently with BP development. Bullae developed within 6-8 months of initiation of PD-1/PD-L1 inhibitors; however, a smaller subset of patients did not develop bullae for 1-1.5 years following initiation of therapy. Mean time to pruritus was similar for pembrolizumab and nivolumab at 19 and 21 weeks, respectively. Development of BP required discontinuation of immunotherapy in 76% (16/21) of cases.

CONCLUSION

Prodromal or "non-bullous" variants of BP must be considered in patients treated with checkpoint inhibitors who develop protracted or worsening pruritus. Early diagnostic immunological evaluation of the skin may lead to improved patient outcomes by facilitating timely initiation of treatment and prevent disruptions in cancer therapy.

A case report of bullous pemphigoid associated with a melanoma and review of the literature

The association of bullous pemphigoid with melanoma remains controversial and poorly understood. Recent studies report the presence of the bullous pemphigoid antigen, BP180, in melanoma cells, yet not normal melanocytes, suggesting an underlying mechanism for cases of melanoma-associated bullous pemphigoid. We report on an 88-year-old woman who showed a temporal relationship between the development of bullous pemphigoid and melanoma. The patient did not receive programmed death ligand 1 inhibitor therapy and improved rapidly following complete excision of her melanoma, with clobetasol, doxycycline, and niacinamide. We review the literature on the relationship between bullous pemphigoid and melanoma, and propose a mechanism underlying a melanoma-associated bullous pemphigoid.

Lupus-like cutaneous reaction following pembrolizumab: An immune-related adverse event associated with anti-PD-1 therapy

PD-1 (programmed cell death-1) inhibitors, used to treat metastatic melanoma and other malignancies, are associated with development of immune-related adverse events in the skin. Such reactions include morbilliform eruptions, vitiligo, alopecia areata and bullous pemphigoid. In this report, we describe a patient who developed a lupus-like cutaneous reaction in the setting of pembrolizumab therapy for metastatic melanoma, adding to the spectrum of reactions which may be observed in association with PD-1 inhibitor therapy.

Management of the cutaneous adverse effects of antimelanoma therapy

The advent of targeted therapy and immunotherapy has revolutionized the management of advanced melanoma. However, these novel therapies are associated with adverse effects (AEs), of which cutaneous toxicities are the most frequently observed. These cutaneous AEs can exert significant morbidity and impact on patient quality of life, hence the recognition and management of AEs is fundamental in preventing interruption or cessation of survival-prolonging treatments. Additionally, knowledge of these AEs are necessary in order for healthcare professionals to counsel patients when starting treatment and in the initiation of AE prophylaxis. The incidence and clinical presentation of the cutaneous toxicities of novel melanoma therapies will be discussed, and treatment guidelines provided.

Cutaneous Eruptions in Patients Receiving Immune Checkpoint Blockade: Clinicopathologic Analysis of the Nonlichenoid Histologic Pattern

Cutaneous eruptions are among the most common immune-related adverse events (irAEs) associated with anti-programmed cell death protein 1/programmed cell death ligand 1 therapy, and are often clinically and histologically characterized as lichenoid. Nonlichenoid patterns may also occur and are likely to be encountered by surgical pathologists, given the increasing clinical use of these agents. The purpose of this study is to describe the histopathologic features of nonlichenoid cutaneous irAEs from patients receiving anti-programmed cell death protein 1/programmed cell death ligand 1 therapies for a variety of underlying advanced malignancies. Sixteen patients with 17 biopsied eruptions were included from 2 academic institutions with extensive experience administering and monitoring responses to immune checkpoint blockade as well as treating the potential side effects. Eruptions occurred a median of 10 days (range, 1 d to 11.4 mo) after treatment initiation. Nearly half of specimens demonstrated either a psoriasiform/spongiotic or an urticarial-type reaction pattern on histologic review. Patterns consistent with Grover disease, bullous pemphigoid, and granulomatous dermatitis were also observed. Nearly two-thirds of patients required systemic corticosteroids for treatment of the cutaneous irAE, and 19% of patients discontinued immunotherapy due to their skin eruptions. 75% of patients showed an objective antitumor response. The diverse array of nonlichenoid cutaneous irAE presented here should reflect and inform the scope of histologic patterns encountered by the practicing surgical pathologist. Such eruptions are seen in patients with a variety of underlying tumor types, many of whom ultimately demonstrate a favorable response to immune checkpoint blockade.