A Proposal for Progression-Free Survival Assessment in Patients with Early Progressive Cancer

Progression-free survival (PFS), which is evaluated in oncology clinical trials, is determined based on tumor progression evaluated according to an assessment schedule. There is possibly a bias in median PFS and hazard ratio (HR) for PFS depending on the assessment schedule referring to randomized controlled trials (RCTs) in patients with metastatic colorectal cancer.

We re-analyzed the PFS in the FTD/TPI phase 2 trial by changing the assessment schedule. To assess biases in median PFS and HR for PFS resulting from different assessment schedules, we performed a computational simulation.

The reanalysis of FTD/TPI phase 2 trial and the simulation results showed that there were biases in median PFS and HR for PFS.

In RCTs for early progressive cancer, median PFS is dependent on the assessment schedule; however, HR for PFS can be assessed without clinically-meaningful differences between assessment schedules, regardless of biomarker assumptions.