A real-world picture of biomarker testing in metastatic bladder cancer: A comprehensive assessment of 19,979 patients treated in the US and Europe.

Abstract

4570 Background: Recent advances in the molecular characterization of bladder cancer (BC) have led to the development and approval of several targeted therapies in metastatic BC, and biomarker testing is recommended by all guidelines for treatment decision-making. This real-world study aimed to examine patterns of biomarker testing in clinical practice and correlate testing with molecular-guided treatment in patients (pts) with metastatic BC. Methods: The IQVIA Oncology Dynamics database, an IQVIA oncology cross-sectional survey collecting anonymized real-world patient-level data from anonymized records of drug-treated cancer pts, was used to identify mBC pts in the US, EU4 (France, Germany, Spain, Italy), and UK from January 2017 to December 2024. We assessed biomarker testing data using descriptive analyzes. Results: A total of 19,979 mBC pts were included in this analysis (EU4 + UK: 11,963 pts; US: 8016 pts). FGFR testing has steadily increased over the years in EU4 + UK (from 7% in 2017 to 24% in 2024) and in the US (from 34% in 2019 to 61% in 2024); FGFR alterations were identified in 25.8% of pts in EU4 + UK versus 12.5% in the US. PDL1 testing has also increased over time in both regions; (PDL1 > 10% in 58.9% in EU4 + UK and 57.6% in the US). Microsatellite Instability (MSI) testing and NTRK testing were performed in 12.5% and 8.3% of all pts from EU4 + UK (MSI: 2023-2024; NTRK: 2020-2024). Of these, 24.7% were MSI-high and 5.4% were positive for NTRK alterations. Next Generation Sequencing (NGS) data has been collected since Q1 2022, with an overall testing rate of 9.6% in EU4 + UK and 12.8% in the US. NGS testing has increased in the US over the years (from 3% in 2022 to 65% in 2024). Tumor Mutational Burden (TMB) results are available for pts from EU4 + UK, with TMB > 10 in 55.2% of pts. Regarding the use of targeted therapy, only 230 pts with FGFR3 alterations received any FGFR inhibitors as current or prior treatment, representing 22.9% of positive pts. NTRK inhibitors were used in only 2 pts with positive results (5.7%). Conclusions: To our knowledge, this is the largest real-world study evaluating biomarker testing in mBC pts, providing meaningful insights. Our data show an overall low percentage of biomarker testing in clinical practice, but there has been an increase in ordering over the years. Despite the increase, only a limited proportion of patients are treated with targeted therapy, reflecting drug access barriers. We also noted a geographic variation in the positivity rate of FGFR3 alterations, with a higher incidence in patients from EU4 + UK compared to the US. Additionally, the rate of high TMB and positive PDL1 was higher in our data set when compared to historical data; further studies are warranted to better understand these differences. Our study has some limitations, such as the potential for bias and lack of outcome analysis.