Perspectives on Psoriasiform Adverse Events from Immune Checkpoint Inhibitors: Lessons Learned from Our Practice

Dermatologic toxicities related to cancer immunotherapy

Immunotherapy has revolutionized cancer treatment, offering significant survival superiority for advanced malignancies. However, immunotherapy is associated with various immune-related adverse events, one of the most common of them being dermatologic toxicities. Previous studies have reported dermatologic adverse events in almost half of the cancer patients undergoing immunotherapy. The spectrum of dermatologic toxicities ranges from mild, self-limiting reactions to severe, life-threatening conditions, and includes maculopapular rash, pruritus, vitiligo-like depigmentation, psoriasiform eruption, lichenoid eruption, bullae, photosensitivity, hair loss, nail changes, Stevens-Johnson syndrome, and toxic epidermal necrolysis. The management strategies are based on personalized treatment plans, multidisciplinary approaches, and timely therapeutic interventions aimed at addressing dermatologic toxicities while preserving immunotherapy efficacy. Based on the latest findings, this paper offers a novel perspective and provides an evidence-based review of the pathogenesis, manifestations, incidence, grading, clinical management, and prognostic significance of these toxicities, underlining the importance of balancing the efficacy of immunotherapy with timely and proactive management of their dermatological toxicities to enhance patient outcomes and quality of life.

Immune Checkpoint Inhibitor-Associated Cutaneous Adverse Events: Mechanisms of Occurrence

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs' unique molecular action that is mainly mediated by the activation of cytotoxic CD4+/CD8+ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs.

Cytokine release syndrome induced by anti-programmed death-1 treatment in a psoriasis patient: A dark side of immune checkpoint inhibitors

In recent years, cancer immunotherapy has introduced novel treatments, such as monoclonal antibodies, which have facilitated targeted therapies against tumor cells. Programmed death-1 (PD-1) is an immune checkpoint expressed in T cells that regulates the immune system's activity to prevent over-activation and tissue damage caused by inflammation. However, PD-1 is also expressed in tumor cells and functions as an immune evasion mechanism, making it a therapeutic target to enhance the immune response and eliminate tumor cells. Consequently, immune checkpoint inhibitors (ICIs) have emerged as an option for certain tumor types. Nevertheless, blocking immune checkpoints can lead to immune-related adverse events (irAEs), such as psoriasis and cytokine release syndrome (CRS), as exemplified in the clinical case presented by Zhou et al involving a patient with advanced gastric cancer who received sintilimab, a monoclonal antibody targeting PD-1. Subsequently, the patient experienced exacerbation of psoriasis and CRS. The objective of this editorial article is to elucidate potential immunologic mechanisms that may contribute to the development of CRS and psoriasis in patients receiving ICIs. It is crucial to acknowledge that while ICIs offer superior safety and efficacy compared to conventional therapies, they can also manifest irAEs affecting the skin, gastrointestinal tract, or respiratory system. In severe cases, these irAEs can lead to life-threatening complications such as circulatory shock or multiorgan failure. Consequently, it is recommended that patients receiving ICIs undergo regular monitoring to identify and manage these adverse events effectively.