P91: Cutaneous adverse events of immune check point inhibitors nivolumab, pembrolizumab and atezolizumab: a multicentric study

Vaishnavi Gowda Aster Medcity, Kochi, India The most important expedient in oncology has been the advent of immune checkpoint targeting agents, which are monoclonal antibodies, causing activation of the immune system and generating durable antitumour response in a wide array of advanced solid organ malignancies. However, this nonspecific enhancement of the immune system can lead to immunological intolerance and increase the risk of adverse events (AEs), known as immune-related adverse events (irAEs), which are often dose limiting and can lead to discontinuation of therapy. As per the Western literature, cutaneous irAEs occur in more than half the patients undergoing treatment. However, their occurrence is relatively rare in an Indian set-up. Our aim was to analyse the most prevalent AEs with the immune checkpoint inhibitors (CPIs) nivolumab, pembrolizumab and atezolizumab, to determine the proportion of patients demonstrating these AEs and to classify the AEs as per the Common Terminology Criteria for Adverse Events (CTCAE). All patients attending the oncology outpatient departments at two centres, treated with these agents during the period of June 2019 to June 2021 were included following ethical clearance. A total of 54 patients were included in our study: 46% received pembrolizumab, 39% received nivolumab and 15% received atezolizumab. Sixteen per cent received combination therapy with another immunotherapeutic or cytotoxic agent. Pruritus was noted in 78% of patients, followed by eczema in 18%, folliculitis and pustular eruptions in 18%, cellulitis in 7% and scrotal swelling with erosions in 4% of patients. Severe irAEs noted in four patients were of immunobullous, alteration of melanocytes, inflammatory and drug rash aetiologies. A single case of bullous pemphigoid (grade 3 rash) was noted in a 68-year-old receiving pembrolizumab for hepatocellular carcinoma. Vitiligo was noted after four cycles of pembrolizumab for malignant melanoma. Follicular lichen planus was noted in a patient on nivolumab for Hodgkin’s lymphoma, following the fifth cycle. Stevens–Johnson syndrome was noted following one cycle of pembrolizumab for adenocarcinoma of lung. Improved survival outcomes were noted with lichenoid, vitiligo and immunobullous eruptions. No increased frequency in irAEs was noted as the CPI doses were escalated or combined with other immunotherapeutic agents. With the emerging interest in CPIs conferring durable disease control in advanced malignancies, we profiled the incidence and spectrum of cutaneous AEs of these agents and their associations with clinical improvement in a cohort of 54 patients. Although the frequency of irAEs is mainly dependent on the agents used, the genetic constitution of the individual also plays an important role. This may be the reason for a smaller incidence of AEs in Indian patients. Here, at two of the largest centres of CPI administration, we report a decreased incidence of irAEs and cutaneous manifestations of CPIs in India.