Disease control with prior platinum-based chemotherapy is prognostic for survival in patients with metastatic urothelial cancer treated with atezolizumab in real-world practice.
BACKGROUND
Atezolizumab, a programmed-death ligand-1 (PD-L1) inhibitor, is a novel treatment option for patients with metastatic urothelial cancer (mUC). Clinical prognostic factors, survival outcomes, and the safety of patients with mUC treated with atezolizumab, in a real-world setting, were investigated.


PATIENTS AND METHODS
62 patients with mUC, treated at the Institute of Oncology Ljubljana between May 8th 2018 and Dec 31st 2019, were included. Response rates and immune-related adverse events (irAE) were collected. Progression-free survival and overall survival times were assessed using the Kaplan-Meier method. The Cox proportional hazards model was applied to identify the factors affecting survival.


RESULTS
Of 62 patients, five (8.1%) have not yet been evaluated and 20 (32%) died prior to the first radiographic evaluation. We observed clinical benefit in 19 (33%), objective response in 12 (21%), and complete response in five (9%) patients. Median overall survival for the whole population was 6.8 (95% CI, 2.6-11.0), for platinum-naïve 8.7 (95% CI: 0.8-16.5), and for the platinum-treated group 6.8 (95% CI, 3.7-10) months. At the 5.8 (0.3-23.1) month median follow-up, the median duration of the response was not reached. IrAE occurred in 20 (32%) patients and seven (11%) of them discontinued the treatment. Multivariate analysis in platinum-treated patients showed that a treatment-free interval of more than six months was prognostic for overall survival (OS).


CONCLUSIONS
Responses to atezolizumab led to long disease remission in a subset of our patients. The median OS in our real-world population was compromised by a large percentage of patients with poor ECOG performance status (PS). A treatment-free interval from chemotherapy was associated with the longer survival of platinum-treated patients with mUC receiving further atezolizumab.
['Mencinger|Marina|M|', 'Mangaroski|Dusan|D|', 'Bokal|Urska|U|']
urothelial cancer atezolizumab prognostic factors overall survival PD-L1 inhibitor bladder immune checkpoint inhibitor