PATRIOT II: An ambispective, observational, multicenter, 2-cohort study of avelumab (Ave) first-line maintenance (1LM) in locally advanced/metastatic urothelial carcinoma (la/mUC) in the United States.
Authors: Grivas Petros , Barata Pedro C. , Moon Helen , Hutson Thomas E. , Gupta Shilpa , Sternberg Cora N. , Pickard A. Simon , Dave Vaidehi , Han Natalia , Shillington Alicia C. , Devgan Geeta , Kim Ruth , Thakkar Sheena , Katzenstein Howard , Bhanegaonkar Abhijeet , Liu Frank , Sonpavde Guru P. 
Published: February 2022

TPS578 Background: The randomized phase 3 JAVELIN Bladder 100 trial demonstrated overall and progression-free survival (OS and PFS) benefit with Ave 1LM for la/mUC not progressed with platinum-containing chemotherapy (PCT). PATRIOT II aims to understand real-world treatment (tx) patterns, patient-reported outcomes (PRO), and healthcare resource utilization (HCRU; eg, hospitalizations and emergency department visits) before and during Ave 1LM treatment. Methods: PATRIOT II is an ongoing, real-world, observational study in ≤25 US oncology centers with 1) an ambispective cohort of patients (pts) initiating PCT (n = 100), a subset of whom may continue to Ave 1LM and 2) a retrospective cohort initiated on Ave 1LM (n = 150). Sample size assumes noninferiority in HCRU and PRO pre and post 1LM initiation using paired t-tests with effect size of ≤0.3 as noninferior: ≥71 patients continuing to 1LM. In the ambispective cohort, pts with histologically confirmed la/mUC newly initiating 1L PCT are enrolled. While pts are receiving PCT and 1LM (for those who receive it), data will be collected on disease characteristics, response to tx, survival, adverse events (AEs), and HCRU for ≤52 wks after study initiation. PROs are captured using Rand SF-36 question 1, FACT Bladder Symptom Inventory – 18 and Cancer Treatment Satisfaction Questionnaire. Primary outcomes include OS and PFS from both PCT and 1LM initiation; secondary outcomes are changes in PROs and HCRU from PCT to 1LM. Analysis will be conducted at following time points: 1) baseline characteristics after full enrollment; 2) 6 months after study initiation to assess tx changes and rationale, OS, PFS, HCRU, and PRO changes from baseline; 3) at study conclusion (wk 52 after study initiation). In the retrospective cohort, pts with la/mUC who initiated Ave 1LM are enrolled. Chart data encompasses PCT and 1LM periods. Disease characteristics, response to tx, survival, AEs, and HCRU are collected. Primary outcomes are OS and PFS from initiation of PCT and 1LM start. Secondary outcomes are changes in HCRU before and after 1LM. Analysis will be conducted at following time points: 1) baseline characteristics after full enrollment, PCT, and response to tx; 2) 6 months after study initiation to assess tx changes since baseline, including dose changes, tx discontinuation/change rationale, survival rates (censoring for differential duration of follow-up), and HCRU outcomes; 3) at study conclusion to analyze endpoints up to wk 52 following study initiation. Analyses for both cohorts include Kaplan-Meier and Cox regression for time-to-event endpoints and paired t-tests for pre/post 1LM. Enrollment commenced in June 2021. 5 and 18 pts are enrolled to date in the ambispective and retrospective cohorts, respectively, from 6 of 11 activated sites. Initial results are anticipated in May 2022.