Abstract 797: COVID-19 vaccines in patients with solid tumor cancers receiving immune checkpoint inhibitors
Authors: Gilbert Danielle , Hu Junxiao , Lam Elaine T. 
Published: April 2023

Background: The interaction between checkpoint inhibitors (CPI) and Sars-COV-2 vaccines has been understudied. One potential complication in pts receiving CPI is immune-mediated adverse events (irAEs) resulting from overactivation of the immune system. It is unknown whether concurrent CPI and Sars-COV-2 vaccine administration increases the risk of irAEs. This retrospective study examined the incidence of severe irAEs in cancer patients receiving CPI therapy at the time of vaccination against Sars CoV-2.

Methods: Following IRB approval, pts with solid tumors who received any approved CPI since FDA authorization of the COVID-19 vaccine in December 2020 were identified via institutional electronic health record. Pts who received one or more doses of an authorized vaccine within 60 days of CPI treatment were included. The primary endpoint was to evaluate the incidence of severe irAE (one or more of the following: grade 3 AE or above, multi-system involvement, need for hospitalization). Secondary endpoints included time between CPI and vaccination, need for immunosuppressive therapy, and rate of discontinuation of CPI due to irAE. Data was analyzed using descriptive statistics.

Results: 290 pts with bladder, head/neck, liver, skin (melanoma, SCC), renal, and gynecologic cancer were included in analysis. The median age was 67 years (IQR: 59.0-74.0) and 66% pts were male. At the time of vaccination, 201 pts (69.3%) received CPI monotherapy, 53 pts (18.3%) received combination (combo) CPI therapy, and 36 pts (12.4%) received other therapies (chemo, TKIs, etc.) with CPI. The vaccine manufacturer was Pfizer Bio-N-Tech in 162 pts (55.9%), Moderna in 122 pts (42.1%), and Johnson and Johnson in 6 pts (2.1%). The number of vaccinations received was &gt;/= 3 in 214 pts, 2 in 64 pts, and 1 in 11 pts. 30 pts (11.5%) experienced severe irAEs following vaccination. The rate of severe irAEs was 10.3% (30/290) in the total population [6% (12/201) with CPI monotherapy, 19% (10/53) with combo CPI, and 22% (8/36) in the combo CPI-other group]. Severe irAEs occurred after the first vaccine dose in 5 pts (16.7%), second dose in 16 pts (53.3%), and third dose in 9 pts (30%) pts. The median time between CPI treatment and vaccination in pts who experienced irAE was15.5 days (IQR: 10.2-23.0). Hospitalization was required for 19 patients (63.3%). 24 pts (80.0%) required immunosuppressive therapy with a median therapy duration of 98.5 days (IQR 40.2-173.0). 16 pts (53.5%) discontinued CPI therapy following severe irAEs

Conclusions: In this retrospective study, we observed a 10.3% rate of severe irAE in cancer pts receiving CPI concurrently with COVID-19 vaccines. Further investigation in pts with additional cancer types is warranted to help determine best practice guidelines for COVID-19 vaccination in cancer patients receiving CPI

Support: NCI University of Colorado Cancer Center Support Grant 5P30CA046934-30, Health Compass Data Warehouse project

Citation Format: Danielle Gilbert, Junxiao Hu, Elaine T. Lam. COVID-19 vaccines in patients with solid tumor cancers receiving immune checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 797.