Introduction
The evolution of immune checkpoint inhibitors as an effective anticancer
treatment constitutes one of the greatest and successful approaches in
the world of anticancer therapy 1. They are widely
used in the treatment of various cancers such as metastatic melanoma,
non-small cell lung cancer (NSCLC), renal cell carcinoma (RCCs), and
urothelial cancer (UC)They are also employed in other types of
malignancy such as head and neck squamous cell carcinomas (HNSCC),
breast cancer, colorectal cancer, follicular lymphoma, ovarian cancer,
pancreatic cancer, gastric cancer, sarcoma, colorectal cancer,
metastatic merkel cell carcinoma (MCC), prostate cancer, and
hematological malignancies1. Immune checkpoint
inhibitors are of two types: drugs that target PD-1/PD-L1 proteins and
drugs which target cytotoxic T lymphocyte-associated antigen 4 (CTLA-4)
protein. Drugs that act against PD-1 protein are known as PD-1
inhibitors; these are pembrolizumab, nivolumab, cemiplimab while drugs
that act against PD-L1 protein are atezolizumab, avelumab, and
durvalumab2. PD-1/PD-L1 inhibitors exhibit various
immune-related adverse events, particularly due to the misguided
stimulation of the immune system. Various organ-specific adverse effects
related to anti-PD-1/PD-L1 therapy include gastrointestinal, endocrine,
cardio, ocular, renal, and skin as well as adverse events attributed to
systemic inflammation 3. Since their approval by the
US Food and Drug and Administration (2014) and European Medicines Agency
(2015), several cases of cutaneous adverse reactions were reported. The
most frequent immune-related adverse events (irAEs) are related to
cutaneous (dermatological) toxicities (Figure1). The characteristic of
these irAEs ranges from non-specific eruptions to recognizable skin
appearances, which may present acceptable to mild to life-threatening
skin toxicities 4. Most of the cutaneous adverse
reactions occurring with PD-1/PD-L1 inhibitors are usually mild to
moderate in nature and readily manageable with proper supportive care,
and usually resolved following their withdrawal from the drug regime.
Thus, it is essential to establish a strong surveillance system to
monitor the proper safety and toxicity profile of the potential
PD-1/PD-L1 inhibitors. Early recognition is the key in the management
and prevention of cutaneous irAEs, which may limit treatment
interruption and can improve quality of life. The objective of this
article is to evaluate the rate of cutaneous adverse reactions
consistent with anti-PD-1 and anti-PD-L1 drugs and their associated
control management.