Interstitial granulomatous dermatitis and granulomatous arteritis in the setting of PD-1 inhibitor therapy for metastatic melanoma

A scoping review of vasculitis as an immune-related adverse event from checkpoint inhibitor therapy of cancer: Unraveling the complexities at the intersection of immunology and vascular pathology

BACKGROUND/PURPOSE

Vasculitis as an immune-related adverse event (irAE) from checkpoint inhibitor therapy (ICI) to treat cancer is a rare clinical event, and little is known regarding its nosology, clinical manifestations, or response to treatment and outcomes.

METHODS

To address these gaps, we used the Preferred Reporting Items for Systemic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework to further define this complication. Two independent PUBMED searches in September and November of 2022 revealed 127 publications with 37 excluded from title by relevance, 43 excluded by article type, and 23 excluded due to lack of biopsy results, or biopsy negative for vasculitis. Twenty-nine documented cases from 24 publications were included for final analysis. Basic demographics, ICI details, timing of onset of vasculitis symptoms, irAE treatment and outcomes were collected. The vasculitides were classified using 2022 ACR/EULAR Vasculitis Classification Criteria as well as 2012 Revised Chapel-Hill Nomenclature. Adaptations from Naidoo et al. 2023 [1] consensus definitions for irAEs were used and efforts were made to classify steroid-responsive versus unresponsive irAEs.

RESULTS

Of the 29 cases reviewed, the average age of patients was 62.1 ± 11.0, composed of 58.6 % (n = 17) male and 41.3 % (n = 12) female. Prominent cancer types were lung cancer (41.4 %; n = 12), melanoma (41.4 %; n = 12), and renal cancer (10.3 %; n = 3), with majority being stage 4 (75.9 %, n = 22) and stage 3 (10.3 %, n = 3). Only 8 cases met the ACR/EULAR criteria, and by Chapel-Hill Nomenclature, approximately a third were small-vessel vasculitis (31.0 %; n = 9) with n = 4 positive for ANCA. Most biopsies were taken from the skin (37.9 %, n = 11) and kidney (24.1 %, n = 7). Patients were either treated with single (65.5 %, n = 19), dual (17.2 %; n = 5), or sequential (17.2 %; n = 5) ICI regimen which included anti-PD-1 therapy in all but one case, with mean of 8.7 ± 10.5 cycles received. Mean time to onset of symptoms from start of ICI was 7.2 ± 7.8 months, with 55.2 % occurring >3 months since the initial immunotherapy. Vasculitis treatment included glucocorticoids in 96 % of cases and immunotherapy was often discontinued (44.8 %; n = 13). Clinical improvement of irAE was documented in 86.2 % (n = 25). Data were missing in terms of fate of ICI (34.5 %; n = 10) and tumor outcomes (41.4 %; n = 12). Cancer progressed in 20.7 % (n = 6), stable in 34.5 % (n = 10) cases, and 6 patients died of all-causes.

CONCLUSION

Vasculitis as an irAE appears clinically heterogeneous and rare. Among reported cases with adequate documentation, vasculitis is of delayed onset following the initiation of immunotherapy. Outcomes of ICI-vasculitis were generally favorable, responding to glucocorticoids and immunotherapy withdrawal. There is an urgent need for more standardized reporting of rare irAEs such as vasculitis to clarify clinical risks, classification, relationship to immunotherapy and outcomes.

Proof-of-concept study of the caninized anti-canine programmed death 1 antibody in dogs with advanced non-oral malignant melanoma solid tumors

BACKGROUND

The anti-programmed death 1 (PD-1) antibody has led to durable clinical responses in a wide variety of human tumors. We have previously developed the caninized anti-canine PD-1 antibody (ca-4F12-E6) and evaluated its therapeutic properties in dogs with advance-staged oral malignant melanoma (OMM), however, their therapeutic effects on other types of canine tumors remain unclear.

OBJECTIVE

The present clinical study was carried out to evaluate the safety profile and clinical efficacy of ca-4F12-E6 in dogs with advanced solid tumors except for OMM.

METHODS

Thirty-eight dogs with non-OMM solid tumors were enrolled prospectively and treated with ca-4F12-E6 at 3 mg/kg every 2 weeks of each 10-week treatment cycle. Adverse events (AEs) and treatment efficacy were graded based on the criteria established by the Veterinary Cooperative Oncology Group.

RESULTS

One dog was withdrawn, and thirty-seven dogs were evaluated for the safety and efficacy of ca-4F12-E6. Treatment-related AEs of any grade occurred in 13 out of 37 cases (35.1%). Two dogs with sterile nodular panniculitis and one with myasthenia gravis and hypothyroidism were suspected of immune-related AEs. In 30 out of 37 dogs that had target tumor lesions, the overall response and clinical benefit rates were 6.9% and 27.6%, respectively. The median progression-free survival and overall survival time were 70 days and 215 days, respectively.

CONCLUSIONS

The present study demonstrated that ca-4F12-E6 was well-tolerated in non-OMM dogs, with a small number of cases showing objective responses. This provides evidence supporting large-scale clinical trials of anti-PD-1 antibody therapy in dogs.

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.

Rheumatic Manifestations and Diseases From Immune Checkpoint Inhibitors in Cancer Immunotherapy

Immune checkpoint inhibitors (ICIs), which can enhance antitumor immunity and inhibit cancer growth, have revolutionized the treatment of multiple cancers and dramatically decreased mortality. However, treatment with ICIs is directly associated with immune-related adverse events (irAEs) because of inflammation in off-target organs and autoimmunity resulting from non-specific immune activation. These irAEs can cause rheumatic diseases and manifestations such as inflammatory arthritis, polymyalgia rheumatica, myositis, vasculitis, Sicca and Sjogen's syndrome, and systemic lupus erythematosus. Early diagnosis and treatment of these adverse events will improve outcomes and quality of life for cancer patients. The treatment of rheumatic diseases induced by ICIs requires multidisciplinary cooperation among physicians. Furthermore, the underlying mechanisms are not fully understood and it is difficult to predict and evaluate these side effects precisely. In this review, we summarize available studies and findings about rheumatic irAEs, focusing mainly on the clinical manifestations, epidemiology, possible mechanisms, and guiding principles for treating these irAEs.

Immune checkpoint molecule expression is altered in the skin and peripheral blood in vasculitis

Dysfunction of immunoinhibitory signals and persistent T cell activation reportedly play important roles in the development of vasculitis. The skin is one of the most accessible organs, and it is suitable for the characterization of immune cell signatures. However, the inhibitory checkpoint molecules in the skin and their relevance to vasculitis have not been studied. Here, we investigated the profile of immune checkpoint molecules in the skin and peripheral blood of patients with vasculitis and healthy donors. We found that some of the inhibitory checkpoint molecules, including programmed cell death 1 receptor (PD-1), were elevated in T-cells in the blood of patients with systemic and cutaneous vasculitis. In addition, programmed death-ligand 1 (PD-L1) expression was elevated in the skin of patients with cutaneous vasculitis. Histologically, PD-L1 was highly expressed in the vessels in the skin along with CD4⁺ and CD8⁺ T-cell infiltration in patients with cutaneous vasculitis. Notably, plasma soluble PD-L1 levels were increased, and these correlated with C-reactive protein in patients with systemic vasculitis. Our findings suggest that inhibitory checkpoint molecules might be differentially modulated in the skin and peripheral blood of patients with vasculitis, and that the alteration of the PD-L1/PD-1 axis may be associated with the regulation of T-cell activation in vasculitis.

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.

Eosinophilic granulomatosis with polyangiitis: Cutaneous clinical and histopathologic differential diagnosis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, but severe systemic vasculitis that can affect skin and other organ systems. Diagnostic criteria have evolved, and many attempts have been made to classify the vasculitides based on clinical and/or histopathologic features, with an aim to develop standardized criteria. According to the EGPA Consensus Task Force recommendations, EGPA is a syndrome of asthma, eosinophilia, pulmonary infiltrates, and extrapulmonary vasculitis (such as cutaneous involvement with purpura). Histopathologic evidence of vasculitis in EGPA may be associated with eosinophilic infiltration and/or perivascular granulomatous inflammation. We review clinicopathologic criteria of this enigmatic vasculopathy.

Rheumatic Manifestations in Patients Treated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that activate the immune system, aiming at enhancing antitumor immunity. Their clinical efficacy is well-documented, but the side effects associated with their use are still under investigation. These drugs cause several immune-related adverse events (ir-AEs), some of which stand within the field of rheumatology. Herein, we present a literature review performed in an effort to evaluate all publicly available clinical data regarding rheumatic manifestations associated with ICIs. The most common musculoskeletal ir-AEs are inflammatory arthritis, polymyalgia rheumatica and myositis. Non-musculoskeletal rheumatic manifestations are less frequent, with the most prominent being sicca, vasculitides and sarcoidosis. Cases of systemic lupus erythematosus or scleroderma are extremely rare. The majority of musculoskeletal ir-AEs are of mild/moderate severity and can be managed with steroids with no need for ICI discontinuation. In severe cases, more intense immunosuppressive therapy and permanent ICI discontinuation may be employed. Oncologists should periodically screen patients receiving ICIs for new-onset inflammatory musculoskeletal complaints and seek a rheumatology consultation in cases of persisting symptoms.