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

Advances in immunotherapy for mucosal melanoma: harnessing immune checkpoint inhibitors for improved treatment outcomes

Mucosal melanoma (MM) poses a significant clinical challenge due to its aggressive nature and limited treatment options. In recent years, immunotherapy has emerged as a promising strategy for MM, with a particular focus on immune checkpoint inhibitors such as PD-1 and CTLA-4 inhibitors. These inhibitors have demonstrated substantial efficacy by harnessing the body's immune response against tumors. Moreover, adoptive cell transfer (ACT), anti-angiogenic therapy, and combination therapies have garnered attention for their potential in MM treatment. ACT involves modifying T cells to target melanoma cells, showing promising antitumor activity. Anti-angiogenic therapy aims to impede tumor growth by inhibiting angiogenesis, while combination therapies, including immune checkpoint inhibitors and targeted therapies, offer a multifaceted approach to overcome treatment resistance. This comprehensive review explores the advancements in immunotherapy for MM, highlighting the role of diverse therapeutic modalities in enhancing treatment outcomes and addressing the challenges posed by this aggressive malignancy.

Oral Toxicities Associated with Immune Checkpoint Inhibitors: Meta-Analyses of Clinical Trials

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment; however, their oral toxicity profile is not well elucidated. This review aimed to investigate the prevalence of oral toxicities including xerostomia, mucositis/stomatitis, dysgeusia, dysphagia, oral/oropharyngeal pain, oral infections, angular cheilitis, osteonecrosis, osteomyelitis, and oral mucosal reactions with ICIs. A review protocol was registered with PROSPERO (ID: CRD42023391674). A systematic search of ClinicalTrials.gov was conducted as of April 10, 2022. Studies were selected, assessed, and data extracted using PRISMA guidelines. Oral toxicity data were extracted from study arms using a single immunotherapy drug. Meta-analyses were conducted to summarize prevalence of oral toxicities using random-effects models. Of 750 screened records, 95 trials were included in the meta-analysis with published results. Time between study completion and first publication on ClinicalTrials.gov was 1 to 146 months (mean = 20.3, SD = 18.4). Weighted pooled prevalence was 5% (95% CI: 4-6%) for xerostomia, 3% (95% CI: 3-4%) for mucositis/stomatitis, 3% (95% CI: 2-3%) for dysgeusia, 2% (95% CI: 1-2%) for dysphagia, 3% (95% CI: 2-4%) for oropharyngeal/oral pain, 2% (95% CI: 1-3%) for oral candidiasis, and 2% (95% CI: 0-4%) for angular cheilitis. Subgroup differences based on ICI drugs were minimal. No trials reported lichenoid or pemphigoid mucosal reactions. Meta-analysis results revealed low prevalence of oral toxicities with ICIs; however, data reporting was limited and inconsistent. Limitations of study dataset reveal a significant need for systematic collection of oral morbidity data as well as improved consistency and compliance of reporting results on ClinicalTrials.gov.

Ocular Inflammatory Complications of Treatment for Metastatic Melanoma

PURPOSE

To characterize various ocular inflammatory complications arising from metastatic cutaneous melanoma therapies and their management.

METHODS

Retrospective case series of patients who were referred to a tertiary uveitis practice for ophthalmic exam All patients received targeted metastatic cutaneous melanoma treatment, including BRAF/MEK inhibitors and various immunotherapies.

RESULTS

109 patients were identified, with 43 (39.4%) having 65 definitive instances of OIAE. Sixteen different OIAE were identified. Ipilimumab monotherapy and ipilimumab/nivolumab combination therapy were most commonly associated. Anterior uveitis was the most common OIAE (18/65, 27.7%). Thirty patients (69.8%) were managed with observation or topical steroid therapy. Only 4 patients required further therapies for OIAE, with one patient not attaining resolution.

CONCLUSIONS AND RELEVANCE

While a broad range of OIAE was identified, most were not vision-threatening and did not require discontinuation of the associated therapy.

Immune checkpoint inhibitor-induced cutaneous toxicities: a review of histopathologic and clinical features

Immune checkpoint inhibitors (ICIs) represent an emerging treatment option for a variety of cancer types. Through inhibition of programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1), and/or cytotoxic lymphocyte-associated antigen-4 (CTLA-4), ICIs activate the host's immune system causing a heightened anti-tumor response. However, off-target effects of ICIs can result in numerous different immune-related cutaneous adverse events (irCAEs). Beyond impacting quality of life, irCAEs can lead to dose limitations or discontinuation of anti-cancer therapies. Correct diagnosis is necessary for expedient and appropriate management. Skin biopsies are often performed to increase diagnostic accuracy and guide clinical management. An extensive literature review was performed using the PubMed database to identify the reported clinical and histopathologic features of irCAEs. This comprehensive review primarily details the histopathologic features of various irCAEs reported to date. Clinical presentation and immunopathogenesis are also discussed in relation to histopathology.

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.

[Immunopathogenesis of mucous membrane pemphigoid]

A detailed understanding of the immunopathogenesis of mucous membrane pemphigoid (MMP) is of particular importance in view of the mostly difficult diagnostics and treatment of this blistering autoimmune dermatosis. A still unknown disturbance of the body's own immune tolerance leads to the formation of autoreactive cells. As the disease progresses these produce autoantibodies which are directed against structural proteins in the basement membrane zone (BMZ). After they bind to the target antigen, complement factors are deposited along the BMZ and inflammatory cells invade the underlying tissue and produce the characteristic subepithelial blistering. This inflammatory response is associated with fibrosis and scarring in many affected tissues. Most phases of MMP pathogenesis are poorly understood; however, the last few years have shed more light on this processes. These advances are mostly the result of animal and cell culture models. Typical clinical and immunopathological characteristics of MMP, such as oral, conjunctival and skin lesions, are reflected, for example, in an antibody transfer-induced mouse model for anti-laminin 332 MMP in adult mice. Dapsone, as first-line treatment for MMP patients, significantly reduced the severity of these symptoms, and fibrosis in the skin and mucous membranes was also found histologically, which makes the model well-suited for testing new therapeutic approaches for MMP patients and might be of help for further elucidation of the immunopathogenesis of MMP.

Cutaneous manifestations associated with immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block key mediators of tumor-mediated immune evasion. The frequency of its use has increased rapidly and has extended to numerous cancers. ICIs target immune checkpoint molecules, such as programmed cell death protein 1 (PD-1), PD ligand 1 (PD-L1), and T cell activation, including cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). However, ICI-driven alterations in the immune system can induce various immune-related adverse events (irAEs) that affect multiple organs. Among these, cutaneous irAEs are the most common and often the first to develop. Skin manifestations are characterized by a wide range of phenotypes, including maculopapular rash, psoriasiform eruption, lichen planus-like eruption, pruritus, vitiligo-like depigmentation, bullous diseases, alopecia, and Stevens-Johnson syndrome/toxic epidermal necrolysis. In terms of pathogenesis, the mechanism of cutaneous irAEs remains unclear. Still, several hypotheses have been proposed, including activation of T cells against common antigens in normal tissues and tumor cells, increased release of proinflammatory cytokines associated with immune-related effects in specific tissues/organs, association with specific human leukocyte antigen variants and organ-specific irAEs, and acceleration of concurrent medication-induced drug eruptions. Based on recent literature, this review provides an overview of each ICI-induced skin manifestation and epidemiology and focuses on the mechanisms underlying cutaneous irAEs.

Laryngeal Mucous Membrane Pemphigoid as an Immune-related Adverse Effect of Pembrolizumab Treatment

Pembrolizumab is an immune checkpoint inhibitor (ICI) approved for multiple indications in a variety of malignancies. Although generally well tolerated, the potential for significant adverse effects, specifically immune related adverse effects (irAEs) needs to be taken into consideration. Several cases of bullous pemphigoid have been reported as a cutaneous adverse effect of ICIs since 2015, and there are recent reports of mucous membrane pemphigoid (MMP). We present the case of an 84-year-old male with metastatic urothelial carcinoma on treatment with pembrolizumab, who developed laryngeal mucous membrane pemphigoid as an irAE. The diagnosis was based on patient's clinical history and serologic testing, and supported by symptomatic improvement after ICI discontinuation and immunosuppression. Pembrolizumab-induced MMP is a newly described and infrequent irAE, requiring early suspicion and close monitoring for its diagnosis and management.

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

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.

Immune checkpoint inhibitors in cancer therapy: Review of orofacial adverse events and role of the oral healthcare provider

Immune checkpoint inhibitors (ICIs) are a revolutionary class of antineoplastic therapy that restore anti-tumor immunity. Consequences of this enhanced immune response include a multitude of immune related adverse events (irAEs) that can affect any body system, including the mouth. Orofacial irAEs reproduce features of numerous immune-mediated conditions, including oral lichen planus, mucous membrane pemphigoid, and Sjögren syndrome, among others. The aim of this review is to summarize known orofacial irAEs and to familiarize oral healthcare providers with how to identify and manage these toxicities as part of the care team for patients treated with ICIs.

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.

Adverse cutaneous toxicities by PD-1/PD-L1 immune checkpoint inhibitors: Pathogenesis, Treatment, and Surveillance

Introduction-The therapeutic use of humanized monoclonal programmed cell death 1 (PD-1) (pembrolizumab, and nivolumab) and programmed cell death ligand-1 (PD-L1) (atezolizumab, avelumab, durvalumab) immune checkpoint inhibitors (ICPi) as potent anticancer therapies is rapidly increasing. The mechanism of signaling of anti-PD-1/PD-L1 involves triggering cytotoxic CD4+/CD8 + T cell activation and subsequent abolition of cancer cells which induces specific immunologic adverse events that are specific to these therapies. These drugs can cause numerous cutaneous reactions and are characterized as the most frequent immune-related adverse events (irAEs). Majority of cutaneous irAEs range from nonspecific eruptions to detectible skin manifestations, which may be self-limiting and present acceptable skin toxicity profiles, while some may produce life-threatening complications.Objective-.This review aims to illuminate the associated cutaneous irAEs related to drugs used in oncology along with the relevant mechanism(s) and management.Areas covered-Literature was searched using various databases including Pub-Med, Google Scholar, and Medline. The search mainly involved research articles, retrospective studies, case reports, and clinicopathological findings. With this review article, an overview of the cutaneous irAEs with anti-PD-1/PD-L1 therapy, as well as suggestions, have been provided, so that their recognition at early stages could help in better management and would prevent treatment discontinuation.Article highlightsCutaneous adverse effects are the most prevalent immune-related adverse events induced by anti-PD-1/PD-L1 immune-checkpoint antibodies.Cutaneous toxicities mainly manifest in the form of maculopapular rash and pruritus.More specific cutaneous complications can also occur, including vitiligo, worsened psoriasis, lichenoid dermatitis, mucosal involvement (e.g., oral lichenoid reaction), dermatomyositis, lupus erythematosus.Cutaneous manifestations can be life-threatening including Stevens-Johnson syndrome/toxic epidermal necrolysis (TEN).Dermatologic toxicities are usually mild, readily manageable, and rarely result in significant morbidity.Adequate management of the cutaneous adverse event and recognition in early stages could lead to the prevention of worsening of the lesions and limit treatment disruption.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapeutic agents, including immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death protein ligand 1 (PD-L1), have revolutionized cancer treatment. The first immune checkpoint inhibitor (ICI) ipilimumab, an anti-CTLA-4, was approved in 2011. Since then, the US Food and Drug Administration (FDA) has approved more than half a dozen immune checkpoint inhibitors to treat various malignancies. These agents are part of a broader class of chemotherapy agents termed immunotherapy, which selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. While the effects of traditional chemotherapy are well known, the toxicity profile of emerging immune therapies is not fully elucidated. They have been associated with atypical side effects labeled collectively as immune-related adverse events (irAEs).

Bullous pemphigoid in diabetic patients treated by gliptins: the other side of the coin

Bullous pemphigoid (BP) is the most common autoimmune bullous skin disease that affects primarily patients older than 60 years. The majority of BP cases are spontaneous, but BP can also be triggered by certain drugs’ exposures. Since 2011, a growing number of observations has been reporting cases of BP in Type 2 diabetic patients. These forms have been linked to the use of a new category of anti-diabetic drugs called dipeptidyl peptidase inhibitors (DPP-4i) or gliptins, but to date, the exact pathophysiological mechanisms underlying this association are not completely elucidated. Although conventional and gliptin-associated BP are thought to share similar clinical and histopathological features, our thorough review of the most recent literature, shows that these 2 forms are quite distinct: DPP-4-i-associated BP seems to appear at an earlier age than spontaneous BP, it may manifest either as a noninflammatory or inflammatory phenotype, while the conventional form presents with a typical inflammatory phenotype. Additionally, an important distinctive histological feature was recently shown in Gliptin-associated BP: these forms may present a less significant eosinophils infiltrate in the upper dermis of peri-blister lesions compared to the skin of patients with spontaneous BP, and this seems a specific feature of the clinically non-inflammatory forms. In accordance with previous literature, we found that the direct immunofluorescence (DIF) gives identical findings in both DPP-4i-associated and conventional forms of BP which is an IgG and complement C3 deposition as a linear band at the dermal–epidermal junction in perilesional skin. Indirect immunofluorescence shows the presence of IgG circulating autoantibodies in the patient's serum which titer does not differ between spontaneous and DPP-4i-associated BP, while the specificity of these autoantibodies, may be different in spontaneous, induced non-inflammatory and induced inflammatory forms, epitope spreading phenomenon seems to play a role in determining these specificities. Further research, based on integrated epidemiological, clinical, histo-immunological and pharmacogenomic approaches, may give more insight into these forms of BP. This combined approach will allow to better define BP endotypes and to unveil the mechanism of spontaneous or drug-induced breakage of the immunotolerance to skin self-antigens.

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.

European guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part I

This guideline on mucous membrane pemphigoid (MMP) has been elaborated by the Task Force for Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology (EADV) with a contribution of physicians from all relevant disciplines and patient organizations. It is a S3 consensus-based guideline encompassing a systematic review of the literature until June 2019 in the MEDLINE and EMBASE databases. This first part covers methodology, the clinical definition of MMP, epidemiology, MMP subtypes, immunopathological characteristics, disease assessment and outcome scores. MMP describes a group of autoimmune skin and mucous membrane blistering diseases, characterized by a chronic course and by predominant involvement of the mucous membranes, such as the oral, ocular, nasal, nasopharyngeal, anogenital, laryngeal and oesophageal mucosa. MMP patients may present with mono- or multisite involvement. Patients' autoantibodies have been shown to be predominantly directed against BP180 (also called BPAG2, type XVII collagen), BP230, laminin 332 and type VII collagen, components of junctional adhesion complexes promoting epithelial stromal attachment in stratified epithelia. Various disease assessment scores are available, including the Mucous Membrane Pemphigoid Disease Area Index (MMPDAI), the Autoimmune Bullous Skin disorder Intensity Score (ABSIS), the 'Cicatrising Conjunctivitis Assessment Tool' and the Oral Disease Severity Score (ODSS). Patient-reported outcome measurements (PROMs), including DLQI, ABQOL and TABQOL, can be used for assessment of quality of life to evaluate the effectiveness of therapeutic interventions and monitor disease course.

Cutaneous adverse events caused by immune checkpoint inhibitors

IMPORTANCE

Immune checkpoint inhibitors (ICIs) have emerged as active therapies for a variety of cancers. Cutaneous toxicities are common immune-related adverse events and patients will often be referred to dermatologists for evaluation.

OBSERVATIONS

Cutaneous adverse events to ICIs can have a variety of clinical presentations. Among the more common are eczematous, morbilliform, and lichenoid dermatoses, as well as vitiligo and pruritus. Less common adverse events include psoriasiform dermatoses, bullous disorders, and severe cutaneous adverse reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms. Because of the immunologic mechanism of ICIs, there are also a variety of rheumatologic adverse reactions with cutaneous manifestations, such as scleroderma, dermatomyositis, cutaneous lupus erythematosus, and various vasculitides. These cutaneous reactions often respond to topical or systemic steroids, although specific toxicities may have alternative treatments available.

CONCLUSIONS AND RELEVANCE

As they become more widely prescribed, dermatologists will see an increasing number of patients with cutaneous adverse events caused by ICI therapies. Accurately diagnosing and treating these toxicities is paramount to achieving the most favorable outcomes for patients.

Oral manifestations of immune-related adverse events in cancer patients treated with immune checkpoint inhibitors

Immunotherapy with immune checkpoint inhibitors (ICIs) has transformed cancer treatment over the past decade, improving survival rates in numerous advanced cancers. Immune-related adverse events (irAEs) are common and can affect any organ system, with many of these toxicities being well-characterized with clear grading criteria and management approaches. There has been less emphasis on oral manifestations of irAEs. This review provides an overview of oral manifestations of irAEs, including mucosal and salivary gland toxicities, and proposes a grading system and management guidelines. irAEs are common treatment-related toxicities in patients treated with ICIs. Oral irAEs can range from asymptomatic white reticulations to life-threatening mucocutaneous reactions requiring aggressive management with corticosteroids and/or permanent discontinuation of ICIs. Oral healthcare providers should be prepared to identify and manage oral irAEs in collaboration with oncologists and other specialists.

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.

Coexistence of oral mucous membrane pemphigoid and lichenoid drug reaction: a case of toripalimab-triggered and pembrolizumab-aggravated oral adverse events

Toripalimab and pembrolizumab belong to anti-programmed death receptor-1 monoclonal antibodies for the treatment of various cancers. Anti-programmed death receptor-1 therapy can cause mucocutaneous adverse events. Here, we report the first case, to our knowledge, of oral mucous membrane pemphigoid and lichenoid reaction triggered by toripalimab and aggravated by switching to pembrolizumab. Mucous membrane pemphigoid was a definite diagnosis, whereas lichenoid reaction was a clinical diagnosis without pathologic evidence. Although discontinuation of the culprit drugs achieved clinical resolution in most reported cases, multiple studies demonstrated statistically significant associations between the development of dermatologic adverse events and superior clinical outcomes. Thus, more studies are needed to find satisfactory measures in terms of both cancer control and avoidance of severe adverse events.

Clinical profile of cutaneous adverse events of immune checkpoint inhibitors in a single tertiary center

Programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors have demonstrated their efficacy in the treatment of various malignancies. Despite their benefits, their immunomodulatory activities can cause unpredictable cutaneous adverse events (CAE). This study aimed to identify characteristics of CAE in patients treated with PD-1/PD-L1 inhibitors through the medical records, photographs, and pathology reports. Fifty CAE occurred in 47 (2.75%) of 1711 patients treated with PD-1/PD-L1 inhibitors. Pruritic, psoriasiform, urticarial, and acneiform eruptions were the four most common types. Melanoma patients showed CAE more frequently than other malignancies. Acneiform eruption occurred more often at ages under 60 years. Urticarial eruption appeared earlier, while keratoacanthoma appeared later after immunotherapy. The overall survival times were not significantly different between the two groups with and without CAE by Kaplan-Meier analysis (p = 0.055). Studies on CAE may provide more information to understand these drugs and to help manage the patients.

Efficacy and safety of tetracyclines for pemphigoid: a systematic review and meta-analysis

The aim of this review was to evaluate the efficacy and safety of tetracyclines for treatment of pemphigoid. We searched PubMed, EMBASE, Ovid, Web of Science, and the Cochrane Library for studies involving pemphigoid patients treated with tetracyclines published in English before 29 February 2020. References of included studies were also screened to widen the scope of the literature search. Data regarding predefined clinical outcomes of 341 patients from 77 studies were extracted and analyzed. A meta-analysis was conducted on the basis of 4 studies including 2 randomized controlled trials and 2 comparative studies. The patients had a mean age of 74.60 ± 13.18 years, 45.4% were males, and 54.6% were females. There were 185 patients with mild-to-moderate and 143 patients with severe disease. The average initial doses were 1.62 ± 0.39 g/day for tetracycline, 0.20 ± 0.01 g/day for doxycycline, and 0.11 ± 0.05 g/day for minocycline. The average time on tetracyclines was 3.74 ± 5.99 months, and 261 (81.3%) patients reported partial or complete remission. Relapses occurred in 72 (28.3%) cases. Adverse effects were experienced by 130 (41.9%) patients. The pooled ORs for short-term effectiveness, relapse, adverse effects, and 1-year survival in patients treated with oral tetracyclines vs. systemic corticosteroids were 0.40 (95% CI, 0.22-0.76), 0.69 (95% CI, 0.44-1.10), 0.47 (95% CI, 0.27-0.82) and 2.02 (95% CI, 1.16-3.50), respectively. Compared to doxycycline and minocycline, tetracycline was significantly associated with better treatment outcomes and fewer adverse effects (p < 0.05). This review revealed tetracyclines' efficacy and safety in pemphigoid treatment and may offer support for clinical use of tetracyclines in pemphigoid.

Oral side effects of immune checkpoint inhibitor therapy (ICIT): An analysis of 4683 patients receiving ICIT for malignancies at Massachusetts General Hospital, Brigham & Women's Hospital, and the Dana-Farber Cancer Institute, 2011 to 2019

BACKGROUND

Immune checkpoint inhibitors (ICIs) are increasingly accepted as a treatment option for several cancers. Although various systemic immune-related adverse events (irAEs) have been characterized, the effect of ICIs on the oral cavity and contiguous structures is still poorly understood.

METHODS

Electronic medical records of 4683 patients in the Mass General Brigham Registered Patient Data Registry who received ICI therapy (ICIT) between December 2011 and September 2019 were reviewed. Reports of oral conditions were categorized into oral mucosal disorders, xerostomia, and dysgeusia. After applying exclusion criteria, demographic characteristics and clinical features were summarized for the patients who had oral irAEs.

RESULTS

In total, 317 patients developed oral conditions that were associated with ICIT (incidence, 6.8%; 317 of 4683 patients). These conditions included xerostomia (68.5%), oral mucosal disorders (33.4%), and dysgeusia (24.0%). In patients with oral irAEs, respiratory cancer (28.4%) was the most common primary cancer, followed by melanoma (26.2%), and head and neck cancer (14.8%). Oral mucosal disorders developed after the initiation of ICIT between 2 and 851 days (between 1 and 1332 days in patients with xerostomia and between 1 and 1455 days in patients with dysgeusia). Of all oral irAEs, 50.9% developed within 3 months, and 85.5% developed within 12 months.

CONCLUSIONS

Oral side effects appear to be more common among patients who receive ICIT than has been previously reported. Concomitant cytotoxic regimens may exacerbate the risk of oral adverse events, perhaps representing the sum of the effects of different, but simultaneous or sequential, pathogenic mechanisms. Additional studies are warranted to better characterize oral irAEs and their biologic basis.

What's the Price? Toxicities of Targeted Therapies in Breast Cancer Care

Agents with mechanisms novel to breast cancer care have been approved to treat breast cancer. These agents include drugs that target cyclin-dependent kinases, phosphoinositide 3-kinase PI3KCA gene mutations, PARP, checkpoint regulation, and novel antibody-drug conjugates. However, these novel approaches bring a risk of toxicities quite different from those of conventional cytotoxic chemotherapy. Here, we review these agents and discuss related adverse events, with particular attention to endocrine, pulmonary, and dermatologic toxicities. Endocrine toxicities associated with novel cancer therapies for breast cancer are distinct and often present with symptoms related to the specific hormonal deficiencies and rarely hormonal excess. Given the complex and sometimes irreversible nature of these toxicities, once recognized, transdisciplinary management with an endocrinologist experienced with managing drug-related toxicities is encouraged. Drug-related pneumonitis is a serious concern with new targeted therapies. Presentation may not be easily distinguished, and a multidisciplinary team approach can optimize patient care. Heightened awareness is crucial for early detection and treatment. Management should follow recommendations provided by the National Cancer Institute Common Terminology Criteria for Adverse Events and agent-specific guidelines. Cutaneous toxicities from anticancer therapies represent a common and often poorly characterized challenge for patients with breast cancer. Although our understanding of dermatologic effects from novel therapies continues to improve, the breadth of toxicities spans all dermatologic conditions. Targeted therapies offer effective and often novel therapeutic strategies for patients with breast cancer but also bring new adverse event profiles. In this era, it will be important both to closely follow monitoring recommendations and to remain vigilant for emerging toxicities.

New patterns of cutaneous drug eruptions

Cutaneous adverse drug reactions produce a significant clinical, financial, and psychological burden on our healthcare industry. The importance of considering a drug reaction in the cause of any dermatitis is underscored by the diversity of clinical manifestations and the prolific rate of drug discovery and approval. We present an update on the variety of drug reactions encountered in the inpatient and outpatient setting. Immunomodulatory drugs used in oncology will be reviewed separately as their clinical manifestations cross many reaction patters and morphologies.

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.

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.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapy agents, such as immune checkpoint inhibitors, have shown remarkable promise in the treatment of various malignancies. These drugs selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. Due to the novelty of these therapeutic agents, their toxicity profile is less well understood.Meta-analysis results reveal that the overall prevalence of oral mucositis, stomatitis, and xerostomia is lower with checkpoint inhibitors compared to conventional chemotherapy, and head and neck radiation therapy. However, the widespread use of immunotherapy reveals new oral mucosal barrier adverse events, including bullous pemphigoid, mucous membrane pemphigoid, and lichenoid mucositis. Audiovestibular dysfunction can occur from autoimmune-mediated pathways of immunotherapy (adoptive cell) with limited treatment options. Such auditory complications can lead to speech recognition deficits and sensorineural hearing loss. Ocular toxicities are among the most common adverse events resulting from the use of these agents. The majority of ocular immune-related adverse events (irAEs) are mild, low-grade, non-sight threatening, such as blurred vision, conjunctivitis, and ocular surface disease. Serious and sight-threatening events, including corneal perforation, optic neuropathy, and retinal vascular occlusion, can occur but are infrequent. In this chapter, we review the current evidence on the clinical manifestations of oral, audiovestibular, and ocular immune-related adverse events (i.e., irAEs).

Paraneoplastic Pemphigus Revealed by Anti-programmed Death-1 Pembrolizumab Therapy for Cutaneous Squamous Cell Carcinoma Complicating Hidradenitis Suppurativa

A 64-year-old patient developed a widespread autoimmune mucocutaneous blistering disease 3 weeks after the initiation of the anti-programmed death-1 (anti-PD-1) pembrolizumab therapy administered for a locally advanced cutaneous squamous cell carcinoma (SCC) of the buttocks arising from hidradenitis suppurativa. A diagnosis of paraneoplastic pemphigus (PNP) was made based on the presence of a suprabasal acantholysis associated with intercellular deposits of immunoglobulin G and C3 on basement membrane zone. Analysis of the patient's sera was positive on monkey bladder and detected circulating antibodies against desmoglein 3 and desmoplakin I prior to the initiation of pembrolizumab. At that time, the patient had few localized blisters limited to the peri-tumoral skin of the buttocks with acantholysis but without in vivo immune deposits. Pembrolizumab therapy was discontinued and a complete remission of PNP was obtained using oral steroids. Reintroduction of pembrolizumab resulted in flare of PNP. Given the close temporal relation between pembrolizumab initiation and the subsequent clinical expression of a widespread PNP, the patient was diagnosed with pre-existing subclinical PNP exacerbated by PD-1 inhibitor. The extreme rarity of PNP in the setting of cutaneous SCC and the effects of challenge, dechallenge, and rechallenge of pembrolizumab argue in favor of a checkpoint inhibitor related adverse effect. Our case is the first PNP associated with anti-PD-1 therapy and serological follow-up suggest that one infusion of pembrolizumab is sufficient to allow clinical expression of underlying pemphigus auto-immunity.

Genetics and Omics Analysis of Autoimmune Skin Blistering Diseases

Autoimmune blistering diseases (AIBDs) of the skin are characterized by autoantibodies against different intra-/extracellular structures within the epidermis and at the basement membrane zone (BMZ). Binding of the antibodies to their target antigen leads to inflammation at the respective binding site and degradation of these structures, resulting in the separation of the affected skin layers. Clinically, blistering, erythema and lesions of the skin and/or mucous membranes can be observed. Based on the localization of the autoantigen, AIBDs can be divided into pemphigus (intra-epidermal blistering diseases) and pemphigoid diseases (sub-epidermal blistering diseases), respectively. Although autoantigens have been extensively characterized, the underlying causes that trigger the diseases are still poorly understood. Besides the environment, genetic factors seem to play an important role in a predisposition to AIBDs. Here, we review currently known genetic and immunological mechanisms that contribute to the pathogenesis of AIBDs. Among the most commonly encountered genetic predispositions for AIBDs are the HLA gene region, and deleterious mutations of key genes for the immune system. Particularly, HLA class II genes such as the HLA-DR and HLA-DQ alleles have been shown to be prevalent in patients. This has prompted further epidemiological studies as well as unbiased Omics approaches on the transcriptome, microbiome, and proteome level to elucidate common and individual genetic risk factors as well as the molecular pathways that lead to the pathogenesis of AIBDs.

Management of Adverse Events in Cancer Patients Treated With PD-1/PD-L1 Blockade: Focus on Asian Populations

The interaction between programmed cell death protein 1 (PD-1) and its ligand programmed death-ligand 1 (PD-L1) induces exhaustions of cytotoxic lymphocytes in the tumor microenvironment, which facilitates tumor immune evasion. PD-1/PD-L1 blockade therapy, which prevents the receptors and ligands from binding to each other, disrupts the T-cell exhaustion signaling, thereby increasing antitumor immunity. Inspiringly, it has revolutionized the treatment of many different types of cancers including non-small-cell lung carcinoma, melanoma, lymphoma, and so on. However, with the intention of generating an antitumor immune response, PD-1/PD-L1 blockade may also lead to a spectrum of side effects. The profile of adverse events (AEs) of PD-1/PD-L1 blockade is not exactly the same with other immune checkpoint blockades, such as blockade of cytotoxic T-lymphocyte-associated protein 4. Although cutaneous, gastrointestinal, and pulmonary systems are common victims, AEs of PD-1/PD-L1 blockade might occur in any other organ system of the human body. These toxicities can be life-threatening if not managed promptly, and proper treatment intervention is imperative for optimal control and prevention of severe damage. Currently, clinical practice for the management of AEs in PD-1/PD-L1 blockade remains sporadic and variable. The majority of initial clinical trials were carried out in Caucasians. The trials of multiple races usually included a small portion of Asian participants, and results were calculated and interpreted for the entire included subjects without any race-specific conclusions. Therefore, the information on PD-1/PD-L1 blockade in Asians is far from systematic or comprehensive. Recently, as the results of clinical trials of anti-PD-1/PD-L1 agents in Asian populations have been gradually released, we summarized current evidence with a specific focus on the Asian population, hoping to outline strategies and offer guidance on the management of AEs in cancer patients treated with PD-1/PD-L1 blockade in the Asian world.

Dipeptidyl Peptidase-4 Inhibitor-Associated Bullous Pemphigoid

Bullous pemphigoid (BP) is an organ-specific autoantibody-mediated blistering skin disease that mainly affects the elderly. Typical clinical features include the widespread blisters, often preceded by and/or associated with itchy urticarial or eczema-like lesions. BP patients have circulating autoantibodies against BP180 and/or the plakin family protein BP230 both of which are components of hemidesmosomes in basal keratinocytes. Most BP autoantibodies particularly target the epitopes within the non-collagenous NC16A domain of BP180. Clinical findings and murine models of BP have provided evidence of a pathogenic role of anti-NC16A autoantibodies. However, it is largely unknown what triggers the breakage of immunotolerance against BP180 in elderly individuals. The incidence of BP has been increased over the past two decades in several countries. Aside from aging populations, the factors behind this phenomenon are still not fully understood. Neurodegenerative diseases such as multiple sclerosis, Parkinson's disease, and certain dementias are independent risk factors for BP. Recently several case reports have described BP in patients with diabetes mellitus (DM) patients who have been treated with dipeptidyl peptidase-4 inhibitors (DPP-4i or gliptins), which are a widely used class of anti-DM drugs. The association between the use of DPP-4is, particularly vildagliptin, and BP risk has been confirmed by several epidemiological studies. Evidence suggests that cases of gliptin-associated BP in Japan display certain features that set them apart from cases of “regular” BP. These include a “non-inflammatory” phenotype, targeting by antibodies of different immunodominant BP180 epitopes, and a specific association with the human leukocyte antigen (HLA) types. However, recent studies in European populations have found no major differences between the clinical and immunological characteristics of gliptin-associated BP and “regular” BP. The DPP-4 protein (also known as CD26) is ubiquitously expressed and has multiple functions in various cell types. The different effects of the inhibition of DPP-4/CD26 activity include, for example, tissue modeling and regulation of inflammatory cells such as T lymphocytes. Although the pathomechanism of gliptin-associated BP is currently largely unknown, investigation of the unique effect of gliptins in the induction of BP may provide a novel route to better understanding of how immunotolerance against BP180 breaks down in BP.

Disproportionality analysis of bullous pemphigoid adverse events with PD-1 inhibitors in the FDA adverse event reporting system

Objectives: Bullous pemphigoid, an autoimmune dermatological disease, may be associated with the use of a relatively new anti-cancer drug class, PD-1 inhibitors, which includes pembrolizumab and nivolumab. This paper analyzes the signals between PD-1 inhibitors and bullous pemphigoid based upon the reported real-world data. Methods: A pharmacovigilance analysis was performed on the publicly available Adverse Event Reporting System database of Food and Drug Administration. Disproportionality ratios were used to examine a signal between PD-1 inhibitors and bullous pemphigoid. A heat map was generated to depict the signal between PD -1 inhibitor use and skin toxicity adverse events. Results: The analysis indicated that there is a significant signal (PRR = 13.82 [95% CI: 9.99-19.11], Chi-squared with Yates' correction = 420.48) between pembrolizumab use and bullous pemphigoid and that there is a significant signal (PRR = 13.19 [95% CI: 10.57-16.46], Chi-squared with Yates' correction = 869.71) between nivolumab use and bullous pemphigoid. The signals remained statistically significant after stratifying for sex and age for both pembrolizumab and nivolumab. The signal is supported by 35 case reports in which there was evidence of PD-1 inhibitor use and a pemphigoid adverse event. Conclusion: When prescribing PD-1 inhibitors, physicians should monitor closely for symptoms of bullous pemphigoid.

Skin Barrier and Autoimmunity-Mechanisms and Novel Therapeutic Approaches for Autoimmune Blistering Diseases of the Skin

One of the most important functions of the skin besides regulating internal body temperature includes formation of the barrier between the organism and the external environment, hence protecting against pathogen invasion, chemical and physical assaults and unregulated loss of water and solutes. Disruption of the protective barrier is observed clinically in blisters and erosions of the skin that form in autoimmune blistering diseases where the body produces autoantibodies against structural proteins of the epidermis or the epidermal-dermal junction. Although there is no cure for autoimmune skin blistering diseases, immune suppressive therapies currently available offer opportunities for disease management. In cases where no treatment is sought, these disorders can lead to life threatening complications and current research efforts have focused on developing therapies that target autoantibodies which contribute to disease symptoms. This review will outline the involvement of the skin barrier in main skin-specific autoimmune blistering diseases by describing the mechanisms underpinning skin autoimmunity and review current progress in development of novel therapeutic approaches targeting the underlying causes of autoimmune skin blistering diseases.