The study of immune-related adverse events in a community-based centre.

Abstract

2642 Background: The effectiveness of immunotherapy is often hindered by the development of immune-related adverse events (IrAE). Racial minorities were under-represented in the key clinical trials that led to the approval of different immune checkpoint inhibitors (ICI). In this study, we explore the side effect profile of immune checkpoint inhibitors in our patient population that comprises almost entirely of minorities, mostly African Americans (AA) and Hispanics. We hypothesize that due to race-based differences in immune milieu of the body and disease susceptibility, the timing and severity of immunotherapy-related IrAE would be different in AA and Hispanics compared to Caucasians. This can translate into a difference in clinical outcomes as well. There have been some suggestions of a positive association of the development of IrAE with cancer survival, although the data is limited and heterogeneous. The purpose of our study is to study the frequency and severity of IrAEs in racial minority groups, compare them with previous clinical trials population, and add valuable real-world data in this underrepresented group of patients. Methods: A retrospective chart review was performed on adult patients with solid malignancies treated with any ICI between January 1, 2015 and April 30, 2022. Patients were classified according to age (greater/equal to 65y or younger), sex, race (self-identified), primary cancer, and type of immunotherapy received. Outcome data using type and severity of IrAE, time to development of IrAE, and any association with clinical outcomes was collected and analyzed using descriptive statistics as well as univariate analysis. Results: A total of 78 patients were included in the final analysis. The mean age was 68 years; 51% were males; 42.3% were Hispanics, 37% were AA, 19.7% were others, and 1% were Whites. Most common malignancy was lung cancer (65.5%). Most common ICI agent used was Pembrolizumab (n = 52) and 2 patients were treated with combination therapy using Ipilimumab and Nivolumab. 41 (52.5%) patients had IrAE of any grade while 9 (11.5%) patients experienced grade 3 side effects. None of the patients experienced grade 4 side effects. Most common IrAE of any grade was hypothyroidism (n = 14) while most common grade 3 side effect was colitis (n = 6). 31 patients were less than 65y of age. There was no significant difference in IrAE in patients less than 65 years of age vs ≥ 65 years (51.6% vs 53.1%) or grade 3 IrAE (9.6% vs 12.7%). Conclusions: In our study population consisting mostly of AA and Hispanics, the rate of IrAE of any grade as well as grade 3 or 4 IrAE with ICI therapy was comparable to what was seen in clinical trials involving these drugs. This data and its potential effects on survival outcomes need to be analyzed in prospective studies involving a larger number of patients.