Survival Endpoints for Treatment Evaluation in Subjects Treated for Metastatic Breast Cancer: Contribution of Real-life Databases

Overall survival (OS) is considered the most reliable cancer endpoint and used by the Health Rregulatory authorities (HRA). OS presents multiple advantages in cancer randomized controlled trials (RCT): it is universally accepted as a measure of clinical benefit for the patient; it is objectively defined, both in terms of events and date of incidence; it is easily and precisely measured and thus reproducible; it can be exhaustively collected. As such, OS has been validated by HRAs. On the other hand, OS presents some limitations. Observing a benefit on OS may require a large number of patients and/or considerable time for patient follow-up. Costs for trials may be increased, and there might be delays in the introduction of possible beneficial treatments for patients. The development of alternative endpoints that could capture treatment benefit appropriately and be measurable earlier, is central for the evolution of clinical research in oncology.

Real world data (RWD) are defined as other sources than clinical trials such as: electronic medical records, registries, insurance claims, pharmacy records, death certificates and other patient-generated data.

This research is aimed at (i) describing the existing endpoints of survival in real-life setting, (ii) comparing the correlation at individual level with data to clinical trials for related to anti-HER2 targeted therapies and endocrine therapies in MBC. We will investigate the individual correlation between candidate surrogate endpoints and overall survival in a population-based record-computerized database centralizing data on about 20,000 patients from 2008 to 2017 in France.

This work should lead to the estimation of various time-to event endpoints (e.g. OS, PFS, etc), in the real-life setting, for mBC patients. In addition, we will estimate their individual correlation with OS, which should help us highlight potential surrogate endpoints in this setting. We will focuss on three distinct population, accounting for a large population of mBS patients: : patients treated with anti-HER2 targeted agents, patients treated with endocrine therapies and elderly population.