833P - International Guidelines for the Definition of Time to Event Endpoints (Tee) in Renal Cell Cancer (Rcc) Randomised Clinical Trials (Rct): Results of the Datecan Project

Abstract

ABSTRACT Aim: In RCT, use of surrogate endpoints for overall survival is increasingly common, yet the choice of surrogates and their definition are not standardized. As endpoint definitions directly affect the estimation of treatment effects, this limits the usefulness of surrogates in the comparison of results between studies. The aim of the DATECAN Kidney project is to obtain a formal consensus for endpoint definitions by providing recommendations for standardised definitions of TEE in RCT in RCC. Methods: Based on a literature review of RCTs (2006–2009), TEE and the associated events used in their definition were identified. Academic research groups were contacted by the Pilot group (PG) upon suggestions from the Steering Committee (SC) to select clinicians and methodologists for the Rating Group (RG) for the two scoring rounds and a face-to-face meeting. A modified Delphi method was used for establishing consensus. Recommendations were then proposed for final ratification to ensure consistency across definitions. Results: The PG and SC selected 9 potentially applicable TEE in the non metastatic (NM) and metastatic/advanced (MA) disease settings. Among the 42 experts contacted, 36 and 34 participated in the first and second rounds respectively, scoring a total of 121 events for the 9 endpoints. After the first two rounds, consensus was reached for 38 events (31%); and 52 events (43%) respectively. During the face-to-face meeting, consensus was reached for 103 (85%) events including 51 events for which there was a tendency to include (9) or exclude (42) the event. 3 endpoints were recommended in the NM setting: Disease-Free Survival (contra lateral RCC, appearance of metastases, local or regional recurrence, death from RCC, death from protocol treatment), Metastasis-Free Survival (appearance of metastases, regional recurrence, death from RCC); and Local regional Free-Survival (local or regional recurrence, death from RCC) Two endpoints were recommended in the MA setting: Kidney Cancer Specific Survival (death from RCC or from protocol treatment) and Progression-Free Survival (death from RCC or Local, regional, or metastatic progression). Conclusions: Recommendations for standardized definitions of TEE in RCT for RCC were established, thus facilitating the reporting of results and between trial comparisons. Disclosure: All authors have declared no conflicts of interest.