PD-1 maintains CD8 T cell tolerance towards cutaneous neoantigens.

The peripheral T cell repertoire of healthy individuals contains self-reactive T cells1,2. Checkpoint receptors such as PD-1 are thought to enable the induction of peripheral tolerance by deletion or anergy of self-reactive CD8 T cells3-10. However, this model is challenged by the high frequency of immune-related adverse events in patients with cancer who have been treated with checkpoint inhibitors11. Here we developed a mouse model in which skin-specific expression of T cell antigens in the epidermis caused local infiltration of antigen-specific CD8 T cells with an effector gene-expression profile. In this setting, PD-1 enabled the maintenance of skin tolerance by preventing tissue-infiltrating antigen-specific effector CD8 T cells from (1) acquiring a fully functional, pathogenic differentiation state, (2) secreting significant amounts of effector molecules, and (3) gaining access to epidermal antigen-expressing cells. In the absence of PD-1, epidermal antigen-expressing cells were eliminated by antigen-specific CD8 T cells, resulting in local pathology. Transcriptomic analysis of skin biopsies from two patients with cutaneous lichenoid immune-related adverse events showed the presence of clonally expanded effector CD8 T cells in both lesional and non-lesional skin. Thus, our data support a model of peripheral T cell tolerance in which PD-1 allows antigen-specific effector CD8 T cells to co-exist with antigen-expressing cells in tissues without immunopathology.

Multi-center retrospective review of vitiligo-like lesions in breast cancer patients treated with cyclin-dependent kinase 4 and 6 inhibitors.

PURPOSE: Cutaneous adverse effects from cyclin-dependent 4 and 6 kinase inhibitors (CDK4/6i) used in metastatic breast cancer are prevalent and well described. Vitiligo-like lesions have been reported and are rare. They can negatively impact patients' quality of life and may be associated with survival benefits. We describe the clinical characteristics of vitiligo-like lesions in an international cohort of patients treated with CDK4/6i to help improve recognition and management. METHODS: Retrospective review of patients diagnosed with vitiligo-like lesions from CDK4/6i from five academic institutions in the USA and Europe was performed. Ten patients were included in the study. RESULTS: Median age of our patients was 55 (range 37-86). Median progression-free survival was 24 months in 5 patients. The median time to rash was 10 months. Sun-exposed areas such as the arms and face were the most affected areas. Multiple skin-directed therapies such as topicals, laser, and phototherapy were trialed with minor success. Mild repigmentation was seen in one patient treated with ruxolitinib cream. CDK4/6 treatment was discontinued due to the vitiligo-like lesions in one patient. CONCLUSION: Clinical characteristics are similar to previously reported findings in case reports and series. We add topical ruxolitinib as a potential treatment option for these patients and include data regarding progression-free survival that should continue to be collected. No definitive conclusions can be made regarding survival benefits from our cohort. Clinicians should refer these patients to dermatologists to aid with management.

INDIVIDUAL ARTICLE: USCOM Algorithm for the Prevention and Management of Cutaneous Immunotherapy-Related Adverse Events.

BACKGROUND: In 2023, nearly 2 million patients will be diagnosed with cancer in the United States and at least 40% will be eligible for treatment with an immune checkpoint inhibitor (ICI). Cutaneous immune related adverse events (cirAEs) from ICIs are common and include pruritus as well as maculopapular, eczematous, bullous, lichenoid, and psoriasiform reactions. All clinicians interfacing with cancer patients must expedite proper evaluation and diagnosis, treatment, and/or consultation that supports the need for evidence-directed guidelines. MATERIALS AND METHODS: A panel of advisors was selected, and a systematic literature review generated foundational evidence to develop a treatment algorithm for cirAEs via a modified Delphi process. Iterations of the algorithm were performed until the group met consensus. RESULTS: An algorithm that tailors the management of cirAEs was developed based on the CTCAE v.5 grading of skin disorders. Representative clinical images and suggested diagnostic measures, supplement the algorithm. CONCLUSION: Recognition and treatment of cirAEs guided through a multidisciplinary, physician-developed algorithm will limit disruption of immunotherapy, optimize quality of life, and enhance overall outcomes in patients treated with ICIs. J Drugs Dermatol. 2023;22:11(Suppl 1):s3-10.

Topical cholesterol/lovastatin for the treatment of porokeratosis: A pathogenesis-directed therapy.

BACKGROUND: Porokeratosis is associated with mevalonate pathway gene mutations. Therapeutic options are few and often limited in efficacy. We hypothesized that topical therapy that aims to replenish cholesterol, an essential mevalonate pathway end-product, and block the accumulation of mevalonate pathway toxic metabolites could alleviate porokeratosis. OBJECTIVE: To study the efficacy of topical cholesterol/lovastatin in different variants of porokeratosis. METHODS: We enrolled a series of 5 porokeratosis patients,1 with disseminated superficial actinic porokeratosis, 2 with porokeratosis palmaris et plantaris disseminata, and 2 with linear porokeratosis. Patients were genotyped before initiation of therapy. Patients then applied topical cholesterol/lovastatin twice daily to a unilaterally defined treatment area for up to 3 months. The response was evaluated and patients photographed at every visit. RESULTS: Three patients had MVD mutations, and 2 patients had PMVK mutations. Treatment with topical cholesterol/lovastatin (but not cholesterol alone) resulted in near complete clearance of disseminated superficial actinic porokeratosis lesions after 4 weeks of therapy and moderate improvement of porokeratosis palmaris et plantaris disseminata lesions and linear porokeratosis lesions. There were no adverse events. LIMITATIONS: Case series design with a small number of patients. CONCLUSION: Topical cholesterol/lovastatin is an effective and well-tolerated therapy for porokeratosis that underscores the utility of a pathogenesis-based therapy that replaces deficient end products and prevents accumulation of potentially toxic precursors.

Inflammatory eruptions associated with immune checkpoint inhibitor therapy: A single-institution retrospective analysis with stratification of reactions by toxicity and implications for management.

BACKGROUND: There is increasing recognition of distinct inflammatory eruptions associated with checkpoint inhibitors. A better understanding of their severity, therapeutic response, and impact on cancer treatment is needed. OBJECTIVE: To analyze the different rashes associated with immunotherapy referred to our institution's oncodermatology clinic and inpatient consultative service and to evaluate their therapeutic response and impact on immunotherapy. METHODS: We retrospectively reviewed the medical records of patients referred to the oncodermatology clinic or inpatient dermatology service during 2016-2018 at Yale-New Haven Hospital for eruptions that developed during immunotherapy. RESULTS: In total, 98 patients (51 men, 47 women) treated with checkpoint inhibitors developed 103 inflammatory eruptions, with a range of mean latency of 0.2-17.7 months. A minority of patients (25/103; 24.3%) required immunotherapy interruption; most of these cases involved immunobullous (7/8; 87.5%), lichenoid (8/26; 30.8%), maculopapular (6/18; 33.3%), and Stevens-Johnson syndrome-like (2/2, 100%) reactions. Only 3 of 16 (18.8%) patients who had their immunotherapy interrupted had a grade 2 or 3 flare on rechallenge. Most reactions (93/103; 90.3%) responded to dermatologic therapy or immunotherapy interruption. LIMITATIONS: This was a retrospective study from a single tertiary care center. CONCLUSION: A variety of inflammatory reactions might occur from immunotherapy with differing degrees of severity. While most rashes responded to topical treatment, immunobullous and exfoliative presentations frequently interrupted immunotherapy. Increased awareness and early recognition could reduce the need for unnecessary immunotherapy interruption.

Bullous disorders associated with anti-PD-1 and anti-PD-L1 therapy: A retrospective analysis evaluating the clinical and histopathologic features, frequency, and impact on cancer therapy.

BACKGROUND: Bullous disorders associated with anti-programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) therapy are increasingly reported and may pose distinct therapeutic challenges. Their frequency and impact on cancer therapy are not well established. OBJECTIVE: To evaluate the clinical and histopathologic findings, frequency, and impact on cancer therapy of bullous eruptions due to anti-PD-1/PD-L1 therapy. METHODS: We retrospectively reviewed the medical records of patients evaluated by the oncodermatology clinic and consultative service of Yale New Haven Hospital from 2016 to 2018. RESULTS: We identified 9 of 853 patients who developed bullous eruptions (∼1%) that were treated with an-PD-1/PD-L1 therapy at our institution during the study period: 7 presented with bullous pemphigoid, 1 presented with bullous lichenoid dermatitis, and 1 presented with linear IgA bullous dermatosis in the context of vancomycin therapy. In all, 8 patients required systemic steroids, 5 required maintenance therapy, and 8 required interruption of immunotherapy. All 9 patients had an initial positive tumor response or stable disease, but 4 went on to develop disease progression. LIMITATIONS: This was a retrospective study from a single tertiary care center. CONCLUSIONS: Bullous disorders developed in approximately 1% of patients treated with anti-PD-1/PD-L1 therapy at our institution and frequently resulted in interruption of immune therapy and management with systemic corticosteroids and occasionally steroid-sparing agents.

Recurrent Coxsackievirus Infection in a Patient with Lamellar Ichthyosis.

We describe a case of coxsackievirus (CV) A6 infection in a patient with lamellar ichthyosis followed by subsequent CV A8 infection within the same year. Atypical cutaneous features characterized the infection. This observation, combined with the rapidity with which reinfection occurred, suggests that the natural history of CV infection may be altered in patients with underlying ichthyoses.

The Use of Biologic Agents for the Treatment of Cutaneous Immune-Related Adverse Events from Immune Checkpoint Inhibitors: A Review of Reported Cases.

Cutaneous immune-related adverse events encompass a spectrum of dermatological manifestations, including lichenoid reactions, psoriasiform eruptions, eczematous dermatitis, immunobullous disorders, granulomatous reactions, pruritus, vitiligo, and severe cutaneous adverse reactions such as Stevens-Johnson syndrome. The conventional approach to treating high-grade or refractory cutaneous immune-related adverse events has involved high-dose systemic corticosteroids. However, their use is limited owing to the potential disruption of antitumor responses and associated complications. To address this, corticosteroid-sparing targeted immunomodulators have been explored as therapeutic alternatives. Biologic agents, commonly employed for non-cutaneous immune-related adverse events such as colitis, are increasingly recognized for their efficacy in treating various patterns of cutaneous immune-related adverse events, including psoriasiform, immunobullous, and Stevens-Johnson syndrome-like reactions. This review consolidates findings from the English-language literature, highlighting the use of biologic agents in managing diverse cutaneous immune-related adverse event patterns, also encompassing maculopapular, eczematous, and lichenoid eruptions, pruritus, and transient acantholytic dermatosis (Grover disease). Despite the established efficacy of these agents, further research is necessary to explore their long-term effects on antitumor responses.

The Impact of Dermatologic Adverse Events on the Quality of Life of Oncology Patients: A Review of the Literature.

Dermatologic adverse events resulting from oncologic therapy are common and negatively impact patients' quality of life. Dermatologic adverse events include toxicity of the skin, oral mucosa, nails, and hair and are seen with cytotoxic chemotherapy, targeted therapy, immunotherapy, and radiation therapy, with distinct patterns of dermatologic adverse events by drug class. Here, we review the literature on the impact of dermatologic adverse events on quality of life. Studies on quality of life in patients with cancer have relied on scales such as the Dermatologic Life Quality Index and Skindex to demonstrate the association between dermatologic adverse events and declining quality of life. This relationship is likely due to a variety of factors, including physical discomfort, changes to body image, decreased self-esteem, and an effect on social interactions. Addressing such quality-of-life concerns for patients with cancer is critical, not only for patients' well-being but also because decreased satisfaction with treatment can lead to discontinuation of treatment or dose reduction. Prophylactic treatment and early management of dermatologic adverse events by experienced dermatologists can alleviate the negative effects on quality of life and allow continuation of life-prolonging treatment.

Immune Checkpoint Inhibitor-Induced Psoriasis: Diagnosis, Management, and a Review of Cases.

Immune checkpoint inhibitors (ICIs) are effective antitumor agents but are associated with immune-related adverse events. ICI-induced psoriasis commonly presents in patients with a history of psoriasis but may occur de novo, and it has a significant physical and psychosocial impact. ICI-induced and non-ICI-induced psoriasis are likely mediated by similar cytokines, and similar treatments are employed. Topical treatment often suffices, and when needed, several systemic treatments appear to be effective without impacting antitumor response. Development of psoriasis may indicate a superior response to ICIs. Thus, recognition and management of ICI-induced psoriasis is essential to avoid ICI interruption and maximize therapeutic potential.