Validation of PFS as surrogate for overall survival for GBM

Abstract

Abstract Background: Surrogate end points have great potential for use in clinical oncology, but their statistical validation presents major challenges12. A putative surrogate endpoint must be validated at both individual-level and trial-level before it can be used to replace the clinical endpoint in a future clinical trial34. Validated and approved surrogate endpoints are useful in development of new drugs. They save time and money since it takes a shorter time to give results. They also require fewer patients in the clinical trial. Objective: To evaluate progression free survival as a surrogate for overall survival for the patients who have been newly diagnosed with Glioblastoma. Methodology: Individual patients were available from two trials comparing radiotherapy alone (379 patients) with radiotherapy plus chemotherapy (389 patients).Correlation coefficients were estimated between the endpoints of PFS and OS through Cox proportional model and copula models. These methods were a