Introduction
Imunnotherapy has gained a high value in the oncology environment, with benefits for the patients (pts) that are eligible for it. However, these drugs are not completely harmless, and immune related adverse events (IRae) have been reported. There have been reports showing clinical benefit in patients that report IRae. Our mains goal is to show if our study matches the recent literature.

Material/ methods
In our study, we did a retrospective analyses in pts who were treated with checkpoint inhibitors for urotelial cancer in our center, between January 2015 and December 2019. Every patient must have had ECOG performance status of 0-2 and were treated with anti PD-1 or anti PD-L1. for advanced muscle invasive urothelial cancer. Progression free survival (PFS) and overall survival (OS) were evaluated starting from the time of the begining of imunnotherapy. Disease control rate was evaluated [Stable disease (SD) + Partial response (PR) + Complete response (CR)]. Results were compared with pts that developed IRae. Demographic and clinical data were collected and the information was cross-checked with that of the pharmaceutical services. A multivariate logistic regression was used to evaluated significance. Significance (p) of less than 0.05 was considered statistically significant. Statistical analysis was performed in stata.

Results:
A total of 30 pts were included in this study. The median age was 69 (63-88). 22 (74%) were male and 8 (26%) were female. 17 (57%) pts were treated with pembrolizumab, 7 (23%) nivolumab and 6 (20%) atezolizumab. 6 pts had 1st line treatment, 20 pts 2nd line and 4 had 3rd line treatment. 18 (61%) had cisplatin based treatment. 25 (83%) had ECOG PS 0-1. 7pts developed IRae. Every IRae were grade 2 or lower. The most common IRae was hypothyroidism (6pts). 1 pt had pneumonitis and 1 had skin related IRae. Median follow up time was 15 months ( 3.27 - 24.40). Median PFS was 6.3 months (2.1-19.5). Median OS was 13.6 months (7.6- not reached). Disease control rate was higher in the group that developed IRae, 85%(n=7) vs 56% (n=23). However, there was no statistical significance (p=0.19). Median PFS were higher in the IRae group (9.4m vs 5.6m) (p=0.13). Median OS was higher in the IRae group (17.6m vs 12.1m) (p=0.2)

Conclusions:
There seems to be a trend towards clinical benefit in patients that develop IRae with imunne checkpoint inhibition in advanced urothelial cancer. However, due to limitation of the low sample of patients no statistical significance could be established. Prospective trials with higher samples could be evaluated to adress this hipo

Can checkpoint inhibitor immune-related adverse events be a prognosis factor in urothelial cancer?