654 Real world incidence of grade III and higher adverse effects, emergency room utilization and hospital admissions during treatment with commonly used PD-1/PDL-1 targeting immune check point inhibitors

Background The landscape of cancer treatment has changed drastically since the development of Immune Checkpoint Inhibitors (ICI). ICIs have become the cornerstone to various cancer treatments.1 2 The adverse effect (AE) profile of ICI is different than conventional chemotherapy. Nivolumab and pembrolizumab target programmed cell death-1 T-cell receptor, whereas programmed death ligand-1 is targeted by atezolizumab and durvalumab.3 4 Easy tolerability and lack of myelosuppresion make immunotherapy an attractive treatment option. Some AEs can be severe, life-threatening, or even fatal (grade III and higher).1 Much of the data regarding AE profile is from clinical trials. The aim of our study is to review real world single institution AE data on the most commonly utilized ICIs. Methods We reviewed a total of 229 patient charts who had received pembrolizumab, nivolumab, durvalumab or atezolizumab at Saint Francis Hospital in Hartford, CT, USA. 53 patients were excluded given lack of records or because they received less than 2 cycles of treatment. Results 176 patients were included in the final analysis. ICIs were discontinued in 25/176 (14.2%) patients secondary to AE. 24/176 (13.6%) patients had grade III or higher AEs reported. 10/95 (10.5%) patients who received pembrolizumab developed grade III/IV AEs (8 pneumonitis, 2 nephritis). 5/45 (11.1%) patients treated with nivolumab developed grade III/IV AEs (2 pneumonitis, 1 new-onset DKA, 1 nephritis, 1 myositis). 8/19 (42.1%) receiving durvalumab had grade III or higher AEs (6 pneumonitis, 1 sepsis, 1 colitis). Lastly, 1/17 (5.8%) in atezolizumab group developed grade III/IV AE (colitis). 96/176 (54.5%) patients had one or more ER visit and 91/176 (51.7%) were admitted to the hospital for various reasons one or more times. Conclusions ICIs have a relatively safe drug profile. 86.4% of our studied population did not develop any grade III or higher AEs. The main reason for ICI discontinuation was disease progression rather than AE. The most common grade III/IV AE was pneumonitis. Durvalumab had the highest incidence of AE, pneumonitis, which is likely related to radiation use prior to immunotherapy. Acknowledgements N/A Ethics Approval Institutional Review Board approval - IRB#: SFH-19–72 References Azoury SC, Straughan DM, Shukla V. Immune checkpoint inhibitors for cancer therapy: clinical efficacy and safety. Curr Cancer Drug Targets 2015;15(6):452–62. Kyi C, Postow MA. Checkpoint blocking antibodies in cancer immunotherapy. FEBS Lett. 2014 Jan 21;588(2):368–76. doi: 10.1016/j.febslet.2013.10.015. Kroschinsky F, Stolzel F, von Bonin S, Beutel G, Kochanek M, Kiehl M, Schellongowski P; Intensive Care in Hematological and Oncological Patients (iCHOP) Collaborative Group. New drugs, new toxicities: severe side effects of modern targeted and immunotherapy of cancer and their management. Crit Care 2017 Apr 14;21(1):89. doi: 10.1186/s13054-017-1678-1. Hofmann L, Forschner A, Loquai C, Goldinger SM, Zimmer L, Ugurel S, Schmidgen MI, Gutzmer R, Utikal JS, Heinzerling LM, et al. Cutaneous, gastrointestinal, hepatic, endocrine, and renal side-effects of anti-PD-1 therapy. Eur J Cancer 2016 Jun;60:190–209. doi: 10.1016/j.ejca.2016.02.025.