Chronic immune-related adverse events arising from immune checkpoint inhibitors: an update

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment, improving outcomes for many patients. However, toxicities termed immune-related adverse events (irAEs) are limitations of these revolutionary treatments. These irAEs may resolve with treatment or ICI cessation (acute) or persist many months beyond therapy cessation (chronic). Acute irAEs were the first to be recognized and are thus more well studied. However, chronic irAEs have been highlighted in recent years and are becoming a topic of more intensive investigation. These chronic irAEs have been noted to affect many different organ systems, including endocrine, rheumatologic, gastrointestinal, dermatologic, neurologic, and cardiovascular systems. In this review, we discuss current knowledge surrounding the frequency, time course, and risk factors associated with chronic irAEs affecting various organ systems, treatment approaches, and future directions.

Quality of Life Impact in Patients with Cutaneous Toxicities Caused by Epidermal Growth Factor Receptor Inhibitors and Immunotherapy

BACKGROUND

Novel oncologic therapies, including epidermal growth factor receptor inhibitors (EGFR-Is) and immune checkpoint inhibitors (ICIs), are associated with a new spectrum of adverse reactions, with prominent cutaneous toxicities. The impact of cutaneous adverse events (cAEs) on patients' quality of life (QoL) represents an unmet clinical need.

OBJECTIVES

The aims of this study were (1) to assess whether cutaneous toxicities directed therapies are effective in reducing the QoL burden via the submission of 2 patient reported outcome measures (PROMs); (2) to investigate whether class of oncologic therapy, type of cAE and toxicity severity differently impact on patients' QoL.

METHODS

A prospective observational study was conducted at the Dermatology department of the Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy, from October 2018 to October 2019. Patients aged ≥18 years, under therapy with EGFR-Is or ICIs and experiencing a treatment-related cAE were eligible for the study. Dermatology Life Quality Index (DLQI) and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 version 3.0 (EORTC QLQ-C30) were administered to patients at first clinical visit (T0), at 1-month (T1), and at 3-month (T2) dermatological follow-up.

RESULTS

Sixty cAEs of 51 patients have been recorded. A significant difference in the mean score for both DLQI and EORTC QLQ-C30 was found along the 3-months dermatological follow-up (p < 0.0001). A similar QoL improvement was reported for PROMs stratified by class of therapy and toxicity severity (p < 0.0001). No difference was reported for patients with pyogenic granuloma-like lesions and psoriasiform eruption as per DLQI. Class of therapy and toxicity severity did not differently impact on patients' QoL at selected timepoints; we reported a higher EORTC QLQ-C30 score at T2 for patients developing psoriasiform eruption compared to other types of cAEs.

CONCLUSIONS

Early patients' referral to dermatologists and tailored management could result in better QoL.

Updates in toxicities associated with immune checkpoint inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have become a pillar of treatment for numerous cancers with increasing use in combination with other ICIs and in earlier stages of disease treatment. Although effective, ICI use is accompanied by a milieu of potentially bothersome or even life-threatening toxicities known as immune-related adverse events (irAEs), necessitating careful monitoring and early intervention.

AREAS COVERED

In this review, we provide an overview of recent advances surrounding toxicity pathophysiology and treatment in the context of relevant organ systems. An emphasis on current treatments by toxicity, as well as updates on steroid-refractory toxicities, chronic toxicities, and biomarkers will be a focus of this update on the current understanding of irAEs.

EXPERT OPINION

ICI toxicities are a major limitation on the deployment of multi-agent ICI regimens and are thus a major priority to understand, treat, and prevent. Recent developments have led to greater understanding of the pathophysiology of these events, which may lead to improved prevention or mitigation strategies. Further, early studies have also suggested steroid-sparing approaches that may be useful. Ultimately, preventing and managing irAEs will be a key goal toward successful ICI treatment across a broader range of patients with cancer.

Cutaneous Adverse Events of Systemic Melanoma Treatments: A Retrospective Single-Center Analysis

Recent progress in the treatment of advanced melanoma has led to the improved survival of affected patients. However, novel treatments also lead to considerable and distinct skin toxicity. To further characterize cutaneous adverse events (AE) of systemic treatments, we conducted a single-center retrospective study of biopsy-proven cutaneous adverse events of melanoma treatment over a period of 10 years at the University Hospital of Zurich, Switzerland. In 102 identified patients, 135 individual skin AEs developed. Immune checkpoint blockade (ICB) was causal for 81 skin AEs, and 54 were related to targeted therapies (TT). Recorded types of skin AEs included lichenoid, maculopapular, acneiform, urticarial, panniculitis, folliculitis, psoriasiform, granulomatous, eczematous, and others. The incidence of skin AEs was higher with TT (18.54%) than with ICB (9.64%, p = 0.0029). Most AEs were low-grade, although 19.21% of AEs were common terminology criteria for adverse events (CTCAE) Grades 3 or 4. A large spectrum of skin AEs was documented during treatment of advanced melanoma, and distinct phenotypes were observed, depending on treatment classes. AEs occurred earlier during treatment with TT than with ICB, and distinct types of skin AEs were associated with respective treatment classes. This study comprehensively describes skin AEs occurring during systemic treatment for melanoma at a single center.

Immunotherapy for keratinocyte cancers. Part II: Identification and management of cutaneous side effects of immunotherapy treatments

Keratinocytic cancers (KCs), specifically cutaneous squamous cell and basal cell carcinomas, can respond to topical, intralesional, or systemic immunotherapies, but cutaneous adverse events (CAEs) may occur. Understanding these risks, early recognition of these CAEs, and effective treatment may enable patients to continue their anticancer immunotherapies without dose impact. Immune checkpoint inhibitor-related CAEs after KCs can have multiple clinical presentations, with specific observed types including psoriasis and bullous pemphigoid. Cutaneous toxicities can require biopsies to confirm the diagnosis, especially in patients who are not responsive to topical or oral steroids, since the selection of biologic drugs depends on accurate diagnosis. Different types of CAEs from immune checkpoint inhibitors have been associated with different oncologic outcomes in various primary cancer types, and this remains to be determined for KC patients. CAE characterization and management after immune checkpoint inhibitors in KC patients is a rapidly growing field that needs specific and prospective studies.

Incidence and factors associated with cutaneous immune-related adverse events to immune check point inhibitors: An ambispective cohort study

Background

Although immune checkpoint inhibitors (ICIs) have become the frontline treatment option for patients with various advanced cancers due to improved survival, they can be associated with a spectrum of cutaneous immune-related adverse events (cirAEs). However, little is known regarding the occurrence and patterns of cirAE-related ICI therapy in patients of different races other than white populations. Therefore, we investigated the incidence and associated factors of cirAEs among cancer patients in northern Thailand.

Methods

A referral-center-based ambispective cohort study was conducted from January 1, 2017, to March 31, 2021. Based on a linked database and merged patient-level data, adult patients with pathologically confirmed cancer who were diagnosed and received ICI therapy regardless of cancer type and followed up through August 31, 2021, were included. All cirAE-related ICI therapy was based on clinical evaluation and ascertainment by a board-certified dermatologist. The incidence of cirAE-related ICI therapy with confidence intervals (CIs) across cancer- and ICI therapy-specific groups was estimated. Factors associated with cirAEs were evaluated using multivariable modified Poisson regression to estimate risk ratios (RRs) and 95% CIs.

Results

The study included 112 patients (67 men [59.8%]; mean age, 65.0 [range, 31.0-88.0] years), who were mainly diagnosed with lung cancer (56.3%), followed by liver cancer (19.6%). The overall incidence of cirAE-related ICI therapy was 32.1% (95% CI, 24.1-41.4); however, there was no substantial difference in sex, cancer type, or individual ICI therapy. The two identified prognostic risk factors of cirAE-related ICI therapy were age >75 years (adjusted RR, 2.13; 95% CI, 1.09-4.15; P=0.027) and pre-existing chronic kidney disease stages 3-4 (adjusted RR, 3.52; 95% CI, 2.33-5.31; P<0.001).

Conclusions

The incidence of cirAE-related ICI therapy among Thai cancer patients was comparable to that in white populations. Early identification, particularly in elderly patients and those with CKD, should be implemented in clinical practice to help optimize therapeutic decision-making and patient health outcomes.

Diagnostic accuracy of general dermatologists and supportive oncodermatologists for biopsied cutaneous immune-related adverse events

PURPOSE

Supportive oncodermatology has been shown to improve several aspects of care for patients with cancer, but research showing improved diagnostic accuracy as a benefit of supportive oncodermatology is largely lacking. We thus aimed to evaluate different dermatologist groups' diagnostic accuracy for heterogenous cutaneous toxicities, using cutaneous immune-related adverse events (cirAEs) from immune checkpoint inhibitors (ICIs) as a test model.

METHODS

Billing/requisition codes were used to identify patients who initiated programmed death-1/ligand-1 (PD-1/PD-L1) ICIs between 2010 and 2019 at Dana-Farber Cancer Institute/Brigham and Women's Hospital/Massachusetts General Hospital and underwent a subsequent skin biopsy. For each biopsied cirAE, pre-biopsy clinical diagnoses and post-biopsy clinico-pathologic diagnoses were retrospectively obtained from the medical record. Each biopsy-ordering dermatology provider was categorized as a general dermatologist or supportive oncodermatologist on the basis of providing clinical care within a cancer-center or attending on a hospital/clinic service dedicated to anti-cancer drug-related skin toxicities.

RESULTS

Of 4,183 patients who initiated anti-PD-1/PD-L1 therapy between 2010 and 2019, 101 (2.4%) patients collectively had 104 biopsied cirAEs. In more than one-third of all reviewed biopsied cirAEs (n = 39, 37.5%), histopathology results frequently led to revision of the pre-biopsy clinical diagnosis. The rate of initial cirAE misclassification amongst supportive oncodermatologists was significantly lower than that amongst general dermatologists (18/66, 27.3% vs. 21/38, 55.3%; Fischer's-exact-test p = 0.006).

CONCLUSION

Experienced supportive oncodermatologists may benefit patient care through increased diagnostic accuracy for skin toxicities from ICIs. Collectively, these results underscore that both skin biopsy from any dermatology provider and oncodermatology referral (where available) are valuable resources that should be integrated into supportive cancer care.

Challenging Dermatologic Considerations Associated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have emerged as a new paradigm in oncologic care for many malignancies. However, nonspecific immune activation has led to "collateral damage" in the form of immune-related adverse events, with skin being a commonly affected organ. Cutaneous immune-related adverse events include a wide spectrum of clinical presentations and challenging considerations, often necessitating dermatology referral to support diagnosis and management, particularly for atypical presentations or more severe, cutaneous immune-related adverse events that may require specialized dermatologic evaluations including biopsy and histopathology. Close collaborations between oncologists and dermatologists may optimize clinical decision making in the following challenging management settings: non-steroidal therapies for corticosteroid-refractory, cutaneous immune-related adverse events, immune checkpoint inhibitor rechallenge, balancing cutaneous immune-related adverse events and treatments, and immune checkpoint inhibitors in patients with pre-existing autoimmune disease, skin conditions, and organ transplants. These complex clinical decisions that often lack rigorous data should be made in close collaboration with dermatologists to minimize unnecessary morbidity and mortality. This article provides a review of approaches to challenging dermatologic considerations associated with immune checkpoint inhibitor therapies.

Immune-checkpoint inhibitors: long-term implications of toxicity

The development of immune-checkpoint inhibitors (ICIs) has heralded a new era in cancer treatment, enabling the possibility of long-term survival in patients with metastatic disease, and providing new therapeutic indications in earlier-stage settings. As such, characterizing the long-term implications of receiving ICIs has grown in importance. An abundance of evidence exists describing the acute clinical toxicities of these agents, although chronic effects have not been as well catalogued. Nonetheless, emerging evidence indicates that persistent toxicities might be more common than initially suggested. While generally low-grade, these chronic sequelae can affect the endocrine, rheumatological, pulmonary, neurological and other organ systems. Fatal toxicities also comprise a diverse set of clinical manifestations and can occur in 0.4-1.2% of patients. This risk is a particularly relevant consideration in light of the possibility of long-term survival. Finally, the effects of immune-checkpoint blockade on a diverse range of immune processes, including atherosclerosis, heart failure, neuroinflammation, obesity and hypertension, have not been characterized but remain an important area of research with potential relevance to cancer survivors. In this Review, we describe the current evidence for chronic immune toxicities and the long-term implications of these effects for patients receiving ICIs.

Dermatologic immune-related adverse events: The toxicity spectrum and recommendations for management

Immune checkpoint inhibitors are a new class of oncologic drugs that act via the inhibition of checkpoints, thereby unlocking the immune system to attack cancer cells. Their emergence has radically changed the concept of therapy in oncologic patients. However, despite their overall favorable profile, their use has been associated with specific toxicities that may potentially affect treatment. The so-called immune-related adverse events (irAEs) mostly correspond to dysimmune reactions that can affect nearly every organ system, in theory, notably with the development of colitis, hepatitis, pneumonitis, or thyroiditis. Dermatologic irAEs are also among the most common, reaching a rate of approximately 40%. They are characterized by a wide phenotypic range, including mainly eczematous or lichenoid rashes, psoriasis, or autoimmune bullous disorders. Pruritus may accompany the aforementioned rashes or develop as an isolated symptom without the presence of skin changes. Depigmentation and hair/nail changes can be also observed in association with immune checkpoint inhibitor treatment. In the current article, we present an overview of the clinical spectrum of irAEs and provide tips for early recognition and management of dermatologic irAEs. We highlight the role that dermatologists can play in relieving patients and allowing for oncologic treatment to be maintained and administered more safely.