COVID-19 vaccine and incidence of severe immune-mediated adverse events in patients with renal cell carcinoma (RCC) on checkpoint inhibitor immunotherapy (CPI).

e16509 Background: Immune-mediated adverse events (irAEs) can be seen in patients (pts) receiving checkpoint inhibitors (CPI). It is unknown whether the immune response to vaccines against Sars-CoV-2 interacts with the immune activation from CPI therapy. In this retrospective study, we examined the incidence of severe irAEs in pts with renal cell carcinoma (RCC) who received vaccines against Sars-CoV-2 during the course of their CPI therapy. Methods: Following IRB approval, RCC pts who received any CPI treatment since FDA authorization of the first COVID-19 vaccine in March 2021 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 (defined as 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. Data was analyzed using descriptive statistics. Results: Sixty-five pts were included in our analysis with a median age of 66 years (IQR: 58.0, 73.0); 80% pts were male. At the time of vaccination, 26 pts (40.0%) received CPI monotherapy, 12 pts (18.4%) received combination (combo) CPI therapy, and 27 pts (41.6%) received combo therapy with a tyrosine kinase inhibitor (TKI) and CPI. The type of vaccine received was Pfizer Bio-N-Tech in 30 pts (46.2%), Moderna in 33 pts (50.7%), and Johnson and Johnson in 2 pts (3.1%). Six pts received only one vaccination (9.2%), 18 pts received two vaccinations (27.7%), and 40 pts received 3 or more vaccinations (61.5%). Eleven pts (16.9%) experienced severe irAEs following vaccination. Rates of severe irAEs was 3.8% (1/26) with CPI monotherapy, 25% (3/12) with combo CPI, and 25.9% (7/27) with combo CPI and TKI. Severe irAEs occurred after the first vaccine dose in 4 pts (36.4%), second dose in 3 pts (27.3%), and third dose in 4 pts (36.4%) pts. The median time between CPI treatment and vaccination in this group was 11.0 days (IQR: 7.5-15.5). Hospitalization was required for 6 patients (54.5%). Ten pts (90.9%) required immunosuppressive therapy with a median steroid duration of 85.5 days (IQR 36.8, 176.0). Six pts (54.5%) discontinued CPI therapy following severe irAEs. Conclusions: In this retrospective study, the observed rate of severe irAEs in RCC patients who received CPI and COVID-19 vaccine concomitantly was similar to historical controls, suggesting that there is no definite increase in the incidence of severe irAEs in pts undergoing CPI therapy and receiving COVID-19 vaccination. Future confirmatory studies are warranted. Supported by the Health Data Compass Data Warehouse project (healthdatacompass.org)