Disease stabilization with pembrolizumab for metastatic acral melanoma in the setting of autoimmune bullous pemphigoid

Cutaneous Side Effects of Modern Targeted Therapy and Immunotherapy in Patients with Dermatological Malignancies

The advent of immunotherapy and targeted therapies in treating dermatological malignancies has dramatically changed the landscape of dermato-oncology in recent years. Their superior efficacy compared to previous therapeutic options, such as chemotherapy, has resulted in their use in treating devastating malignancies, such as melanoma or unresectable/metastatic basal cell and squamous cell carcinoma. Skin toxicity is a critical safety consideration, among other adverse reactions, that can occur under treatment with these agents. This article aims to summarize the cutaneous side effects of immune checkpoint inhibitors and targeted dermato-oncological therapies. Although the skin side effects of these agents are primarily mild, they can occasionally affect the decision for treatment continuation and the quality of life of the affected patients. Therefore, physicians must be acquainted with the specific cutaneous toxicity profile of such treatments to mitigate their impact on the patients and optimize the overall outcome of dermato-oncological therapy.

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.

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.

Immunotherapy Use in Patients With Lung Cancer and Comorbidities

Immune checkpoint inhibitor (ICI) therapy is now in widespread clinical use for the treatment of lung cancer. Although patients with autoimmune disease and other comorbidities were excluded from initial clinical trials, emerging real-world experience suggests that these promising treatments may be administered safely to individuals with inactive low-risk autoimmune disease such as rheumatoid arthritis or psoriasis, mild to moderate renal and hepatic dysfunction, and certain chronic viral infections. Considerations for ICI in autoimmune disease populations include exacerbations of the underlying autoimmune disease, increased risk of ICI-induced immune-related adverse events, and potential for compromised efficacy if patients are receiving chronic immunosuppression. Immune checkpoint inhibitor use in higher-risk autoimmune conditions, such as myasthenia gravis or multiple sclerosis, requires careful evaluation on a case-by-case basis. Immune checkpoint inhibitor use in individuals with solid organ transplant carries a substantial risk of organ rejection. Ongoing research into the prediction of ICI efficacy and toxicity may help in patient selection, treatment, and monitoring.

The safety and efficacy of immune-checkpoint inhibitors in patients with cancer and pre-existing autoimmune diseases

Objective: This study aims at investigating the safety and efficacy of immune-checkpoint inhibitors (ICIs) in patients with cancer and pre-existing autoimmune disease (AID). Materials & methods: PubMed, Embase and Cochrane Library were searched for relevant studies. The primary end points of the study were immunotoxicity and cancer response. Results: At the early use of ICIs, compared with those with active AID, grade 3-4 AID flare occurred more frequently in patients with inactive AID after treatment with ICIs; and the incidence of grade 3-4 immunotoxic effects was significantly lower in patients undergoing immunosuppressive therapy than those without corresponding treatment. In addition, patients with worsening AID generally obtained a better objective response than those without a flare. Conclusion: This study demonstrates that the toxic effects induced by immunotherapy are generally manageable in patients with cancer and pre-existing AID, some of whom even achieve satisfactory antitumor effects in clinical practice.

Melanoma is associated with an increased risk of bullous pemphigoid: a large population-based longitudinal study

The association between bullous pemphigoid (BP) and melanoma is yet to be investigated. We aimed to assess assess the bidirectional association between BP and melanoma and to delineate the epidemiological features of patients with both diagnoses. A population-based cohort study was performed comparing BP patients (n = 3924) with age-, sex- and ethnicity-matched control subjects (n = 19,280) with regard to incident cases of melanoma. A case-control design was additionally adopted to estimate the risk of BP in individuals with a preexisting diagnosis of melanoma. The prevalence of preexisting melanoma was higher in patients with BP than in control subjects (1.5% vs. 1.0%, respectively; P = 0.004). A history of melanoma confers a 50% increase in the risk of subsequent BP (OR 1.53; 95% CI 1.14-2.06). This risk was higher among males (OR 1.66; 95% CI 1.09-2.54) and individuals older than 80 years (OR 1.63; 95% CI 1.11-2.38), and persisted after adjustment for multiple putative confounders including PD-1/PDL-1 antagonists (adjusted OR 1.53; 95% CI 1.14-2.06). Conversely, the risk of melanoma among patients with BP was slightly elevated, but did not reach the level of statistical significance (adjusted HR 1.13; 95% CI 0.73-1.74). Patients with a dual diagnosis of BP and melanoma were older at the onset of BP and had lower body mass index. A history of melanoma is associated with a 50% increase in the incidence of subsequent BP. Physicians managing patients with both conditions should be aware of this association. Further research is warranted to reveal the underlying mechanism of these findings.

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.

Efficacy and Toxicity of Immune -Checkpoint Inhibitors in Patients With Preexisting Autoimmune Disorders

Immunotherapy is an important armamentarium for cancer treatment nowadays. Apart from their significant effectiveness in controlling disease they also generate potential severe immune related adverse effects. Preexistence of immune related conditions may eventually predispose to the development of more severe complication and extreme caution have been taken in treating these patients. We performed a literature review searching for case reports and case series in order to offer evidence-based data for clinical management of these patients. Preexisting serological-only immune abnormalities or presence of a predisposing genetic background does not seem to confer significant risk but existing data is scarce. Most patients with preexistent autoimmune diseases can probably treated with checkpoint inhibitors as they seem to have at least the same response rate as the general cancer population. Under treatment, a significant part of them (at least 30%) can experience a flare of their baseline disease which can sometime be severe. Life-threatening cases seems rare and disease flare can be generally managed with steroids. The volume of available data is more important for rheumatologic diseases than for inflammatory bowel diseases were more caution should be observed. However, it has to be kept in mind that new immune related adverse effects (IrAE) are seen with a similar frequency as the flare of the baseline disease. Both flare-up's and newly developed IrAE are generally manageable with a careful clinical follow-up and prompt therapy.

Cutaneous adverse events: a predictor of tumour response under anti-PD-1 therapy for metastatic melanoma, a cohort analysis of 189 patients

INTRODUCTION

Cutaneous adverse events (AEs) are the most prevalent toxicity under checkpoint inhibitors in clinical trials. In 'real-life' conditions of use, skin toxicities under anti-PD-1 have not been described to date in a large cohort. The objective of this study was to determine the clinical features of skin toxicities in patients with advanced melanoma receiving anti-PD-1 therapy under 'real-life' conditions of use. Secondary objectives were to evaluate the characteristics of patients with skin toxicities and to analyse associated extra-cutaneous toxicities, progression-free survival (PFS) and overall survival (OS).

PATIENTS AND METHODS

Advanced melanoma patients treated with nivolumab or pembrolizumab between August 2014 and October 2017 were included. Patients lost to follow-up or receiving anti-PD-1 as part of a clinical trial were excluded.

RESULTS

One hundred and eighty-nine patients with metastatic melanoma (with 109 men (57.7%) were included. Cutaneous AE occurred in 39 patients (20.6%). The three most prevalent cutaneous AEs were skin eruption (macular-papular or eczematous) (n = 18, 9.5%), vitiligo (n = 16; 8.5%) and isolated pruritus (n = 5, 2.6%). Grade 3-4 skin toxicity was diagnosed in five patients (2.6%). Atopy (28.2% vs. 12.0%; P = 0.024), hypereosinophilia (20.5% vs. 8.7%; P = 0.046), thyroiditis (17.9% vs. 4.7%; P = 0.011) and renal toxicity (15.4% vs. 4%; P = 0.019) were significantly associated with cutaneous AE. Patients with skin eruption (log-rank = 0.001), vitiligo (log-rank = 0.001) and any type of cutaneous AE (log-rank < 0.001) had a better overall survival.

CONCLUSIONS

Cutaneous AEs are frequent and often manageable toxicity and were a predictor of tumour response in melanoma patients under anti-PD-1 therapy in this cohort.

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.

Immune checkpoint inhibitors in special populations. A focus on advanced lung cancer patients

Immune checkpoint inhibitors (ICIs), including those targeting programmed cell death 1 (PD-1), its ligand 1 (PD-L1), or cytotoxic T-lymphocyte antigen 4 (CTLA-4) have become the standard treatment for several malignancies, including lung cancer. However, some patient populations have been routinely excluded from clinical trials or are underrepresented in these studies, as is the case of elderly patients or patients with poor performance status, brain metastases, solid organ transplant, autoimmune diseases, chronic viral infections (such as human immunodeficiency virus or chronic viral hepatitis B and C), or organ dysfunction. Thus, the safety and efficacy of ICIs in these special populations is still unclear, despite regulatory approval of these agents. This review analyzes and summarizes the available information on the efficacy and safety of ICIs in these special populations, focusing on patients with lung cancer.

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.

To treat or not to treat: Patient exclusion in immune oncology clinical trials due to preexisting autoimmune disease

Newly developed immune checkpoint inhibitors (ICIs) demonstrate impressive clinical activity. However, they can also cause life-threatening side effects. The efficacy and toxicity associated with ICIs both derive from unregulated, enhanced immune activation. Health care providers have been hesitant to prescribe these medications to patients who have preexisting autoimmune disease (AD) because of concerns that this may exacerbate their underlying immune condition. These patients have also been excluded from ongoing ICI clinical trials. However, new data suggest that the potential benefits of ICI treatment may outweigh the potential risks for this patient group as long as physicians also provide sufficient monitoring for AD exacerbations or other side effects. Therefore, it may be appropriate to include patients with advanced malignancies and preexisting AD in ICI clinical trials when no other effective cancer treatment options exist. Overall, physicians should avoid excluding patients from ICI therapy unnecessarily when the potential benefits outweigh the potential risks.

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.

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 Adverse Events of Immune Checkpoint Inhibitors: A Summarized Overview

Background:

The introduction of Immune Checkpoint Inhibitors in the recent years has resulted in high response rates and extended survival in patients with metastatic/advanced malignancies. Their mechanism of action is the indirect activation of cytotoxic T-cells through the blockade of inhibitory receptors of immunomodulatory pathways, such as cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein-1 (PD-1) and its ligand (PD-L1). Despite their impressive therapeutic results, they can also induce immune-related toxicity, affecting various organs, including the skin.

Objective:

To provide an updated summarized overview of the most common immune-mediated cutaneous side effects and their management.

Method:

English articles derived from the databases PubMed and SCOPUS and published between 2009 and 2018, were analyzed for this narrative review.

Results:

The most common adverse cutaneous reactions include maculopapular rash, lichenoid reactions, vitiligo and pruritus, with severity Grade 1 or 2. Less frequent but eventually life-threatening skin side effects, including Stevens-Johnson syndrome, Drug Reaction with Eosinophilia and Systemic Symptoms and Toxic Epidermal necrolysis, have also been reported.

Conclusion:

Basic knowledge of the Immune-Checkpoint-Inhibitors-induced skin toxicity is necessary in order to recognize these treatment-related complications. The most frequent skin side effects, such as maculopapular rash, vitiligo and pruritus, tend to subside under symptomatic treatment so that permanent discontinuation of therapy is not commonly necessary. In the case of life-threatening side effects, apart from the necessary symptomatic treatment, the immunotherapy should be permanently stopped. Information concerning the management of ICIs-mediated skin toxicity can be obtained from the literature as well as from the Summary of Product Characteristics of each agent.

Peptide-based and small synthetic molecule inhibitors on PD-1/PD-L1 pathway: A new choice for immunotherapy?

Blockade the interaction of the programmed cell death protein 1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1) can prevent immune evasion of tumor cells and significantly prolong the survival of cancer patients. Currently marketed drugs targeting PD-1/PD-L1 pathway are all monoclonal antibodies (mAbs) that have achieved great success in clinical trials. With the constantly emerging problems of antibody drugs, small molecule inhibitors have attracted the attention of pharmaceutical chemists due to their controllable pharmacological and pharmacokinetic properties, which make them potential alternatives or supplements to mAbs to regulate PD-1/PD-L1 pathway. However, the insufficient target structure information hinders the development of small molecule inhibitors. Since the publication of human-PD-1/human-PD-L1 (hPD-1/hPD-L1) crystal structure, more and more cocrystal structures of mAbs, cyclopeptides and small molecules with PD-1 and PD-L1 have been resolved. These complexes provide a valuable starting point for the rational design of peptide-based and small synthetic molecule inhibitors. Here we reviewed the non-antibody inhibitors that have been published so far and analyzed their structure-activity relationships (SAR). We also summarized the cocrystal structures with hot spots identified, with the aim to provide reference for future drug discovery.

Immune-checkpoint inhibitors to treat cancers in specific immunocompromised populations: a critical review

INTRODUCTION

Because of their efficacy against numerous cancers, immune-checkpoint inhibitors (ICIs), anti-cytotoxic T-lymphocyte antigen-4, and anti-programmed cell death monoclonal antibodies are being used ever more often in oncology. However, some patients were excluded from clinical trials because of their comorbidities despite their potentially higher cancer frequencies, as is the case for immunocompromised patients. Areas covered: We analyzed reported preclinical and clinical information and evaluated the risk/benefit ratio for four immunocompromised populations: people living with human immunodeficiency virus (PLHs), solid-organ transplant recipients, recipients of hematopoietic stem-cell allografts, and patients with autoimmune diseases. Expert commentary: Information available in the literature is fragmentary and scarce, making it difficult to evaluate the risk/benefit ratio. It can, nonetheless, be noted that ICI use in PLHs seems possible. For solid-organ transplant recipients, the risk for the graft seems elevated. For the other two populations, it is difficult to conclude at this time.

Dermatologic Reactions to Immune Checkpoint Inhibitors : Skin Toxicities and Immunotherapy

The development of immune checkpoint inhibitors [monoclonal antibodies targeting cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1) or programmed death ligand 1 (PD-L1)] represents a major breakthrough in cancer therapy. Although they present a favorable risk/benefit ratio, immune checkpoint blockade therapies have a very specific safety profile. Due to their unique mechanism of action, they entail a new spectrum of adverse events that are mostly immune related [immune-related adverse events (irAEs)], notably mediated by the triggering of cytotoxic CD4+/CD8+ T cell activation. Cutaneous toxicities appear to be one of the most prevalent irAEs, both with anti-PD-1 and anti-CTLA-4 agents or with the newly developed anti-PD-L1 agents, which corresponds to a class effect. They are observed in more than one-third of the treated patients, mainly in the form of a maculopapular rash (eczema-like spongiotic dermatitis) and pruritus. A wide range of other dermatologic manifestations can also occur, including lichenoid reactions, psoriasis, acneiform rashes, vitiligo-like lesions, autoimmune skin diseases (e.g., bullous pemphigoid, dermatomyositis, alopecia areata), sarcoidosis or nail and oral mucosal changes. In addition, the use of anti-CTLA-4 and anti-PD-1 therapies in combination is associated with the development of more frequent, more severe and earlier cutaneous irAEs compared to single agents. In most cases, these dysimmune dermatologic adverse events remain self-limiting and readily manageable. Early recognition and adequate management, however, are critical to prevent exacerbation of the lesions, to limit treatment interruption and to minimize quality of life impairment. This review describes the variable clinical and histopathologic aspects of dermatologic irAEs induced by immune checkpoint inhibitors. Appropriate treatment and counseling are also proposed, with a step-by-step approach for optimized management by both practicing oncologists and dermatologists.

[Dermatologic toxicities of immune checkpoint inhibitors]

The development of immune checkpoint inhibitors (monoclonal antibodies targeting PD-1/PD-L1 or CTLA-4) represents a significant advance in the treatment of multiple cancers. Given their particular mechanism of action, which involves triggering CD4+/CD8+ T-cell activation and proliferation, they are associated with a specific safety profile. Their adverse events are primarily immune-related, and can affect practically all organs. In this context, dermatological toxicity is the most common, though it mostly remains mild to moderate and does not require discontinuation of treatment. More than a third of patients are faced with cutaneous adverse events, usually in the form of a maculopapular rash, pruritus or vitiligo (only in patients treated for melanoma). Much more specific dermatologic disorders, however, may occur such as lichenoid reactions, induced psoriasis, sarcoidosis, auto-immune diseases (bullous pemphigoid, dermatomyositis, alopecia areata), acne-like rash, xerostomia, etc. Rigorous dermatological evaluation is thus mandatory in the case of atypical, persistent/recurrent or severe lesions. In this article, we review the incidence and spectrum of dermatologic adverse events reported with immune checkpoint inhibitors. Finally, a management algorithm is proposed.

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.

Clinical features, predictive correlates, and pathophysiology of immune-related adverse events in immune checkpoint inhibitor treatments in cancer: a short review

Identification and characterization of T-cell regulatory mechanisms, or checkpoints, have led to a wave of drug development aimed at inhibiting these targets to "remove the brakes" of the immune system. This class of anticancer therapeutics, termed immune checkpoint inhibitors (ICIs), has harnessed the potential of the body's own immune system to recognize cancerous cells and selectively eliminate them, in some cases with alarming success. This new breakthrough, however, has not been without its drawbacks. Immune-related adverse events (irAEs) are adverse events encountered during treatment with ICIs that are thought to be mediated through the patient's immune system which can manifest with a variety of symptoms which often resemble autoimmunity. These events range widely in presentation and severity and are reported frequently. Here, we will discuss a large selection of case reports in order to inform the clinician, laboratorian, and researcher of the scope of organ systems affected, the severity of the conditions being encountered, and the responses of these events to treatment, as well as explore the use of ICIs in the setting of preexisting autoimmunity. We will also consider the ability to detect autoantibodies before and during irAEs as well as the correlations that irAEs have with clinical outcomes. Finally, we will conclude by exploring the possibility that two distinct pathways may be contributing to the phenomenon of irAEs within this class of drugs, and the role that this might play in future research and clinical practice.

Pembrolizumab use for the treatment of advanced melanoma

INTRODUCTION

Until recently, overall long term survival in patients with stage IV melanoma was lower than 10%. However, the treatment of melanoma has evolved rapidly over the last few years, with the advent of inhibitors of BRAF and MEK and of immunotherapeutic agents including ipilimumab, nivolumab, and pembrolizumab. Areas covered: This is a comprehensive review of the literature on the role of pembrolizumab in melanoma. Pembrolizumab is a Programmed Death Receptor 1 (PD-1) directed monoclonal antibody which is approved by FDA and EMA for the treatment of patients with metastatic melanoma. Expert opinion: Phase II and III trials demonstrated that pembrolizumab is superior to ipilimumab in previously untreated patients and to chemotherapy in ipilimumab pre-treated patients. Unfortunately, prospectively validated predictive markers are lacking. Immune-related adverse events are particularly interesting and should be managed per the published guidelines. There are still many issues that remain unresolved including: when to stop treatment, biomarkers for choosing a single agent or combination therapy, the optimal schedule of ipilimumab in combination with anti-PD1 monoclonal antibodies, optimal management of adverse events, the role of immunotherapy in specific populations, the optimal sequence of immunotherapy and the BRAF/MEK inhibitor combination in patients.

A multi-hit hypothesis of bullous pemphigoid and associated neurological disease: Is HLA-DQB1*03:01, a potential link between immune privileged antigen exposure and epitope spreading?

Bullous pemphigoid (BP) is the most common autoimmune blistering disease and is linked to IgG recognition of 2 hemidesmosomal antigens, that is, BP230 (BP antigen 1) and BP180 (BP antigen 2, collagen XVII). The association of BP with other systemic diseases, particularly neurocognitive diseases, provides a potential clue in the underlying pathogenesis of BP. The role of HLA-DQB1*03:01 binding to the immunogenic portion of BP180 provides a potential mechanism by which exposure to neuronal collagen BP180 may lead to cutaneous disease. In our proposed multi-hit hypothesis, patients with underlying neuronal disease are exposed to previously sequestered self-antigen, most importantly BP180. Patients with the HLA-DQB1*03:01 allele show an increased T-cell avidity to several epitopes of BP180, particularly the BP180-NC16a domain. Thus, they have a genetic susceptibility to developing BP upon exposure to the target antigen. In a patient with dysregulation of Th1/Th2 balance, anergy is lost and T-cells are subsequently primed resulting in the development of functional autoimmunity against the BP180-NC16a domain leading to clinically overt disease.

Opportunistic autoimmunity secondary to cancer immunotherapy (OASI): An emerging challenge

With "checkpoint inhibitors" targeting PD1/PD-1-ligands or CTLA-4/CD28 pathways, immunotherapy has profoundly modified therapeutic strategies in oncology. First approved in refractory metastatic neoplasms (melanoma and lung adenocarcinoma), it is now being tested broadly in other cancers and/or as adjuvant treatment. For a significant proportion of patients, immunotherapy is responsible for "immunological" events, identified as Immune-Related Adverse Events (irAEs). Owing to the increasing number of prescriptions, identification and management of specific immunological side effects is crucial and requires close collaboration between oncologists and internists and/or other organ specialists. Within irAEs, we propose to individualize the induced autoimmunity by the term "Opportunistic Autoimmunity Secondary to Cancer Immunotherapy" (OASI). The aims of this article are (1) to present the different available checkpoint inhibitors and the OASIs reported with these treatments and (2) to propose practical recommendations for diagnosis, pre-therapeutic assessment and management of OASIs. The need for predictive biomarkers of OASIs occurrence will also be discussed.