title: An overview of randomized clinical trials in metastatic breast cancer: variables affecting regulatory drug approval.
abstract: The aim of this study was to analyse trial variables affecting drug approval in metastatic breast cancer (MBC). A literature search from 2000 to 2012 retrieved 66 phase III randomized controlled trials with reported primary endpoints in MBC and known outcomes in terms of approval. The influence of the primary endpoint, the line of therapy, crossover and the sample size was analysed. The primary endpoints used most frequently were progression-free survival (PFS) and time to progression or time to treatment failure (N=47; 71%). Overall survival (OS) was a primary endpoint in nine trials (14%). In 26 trials (39%), statistically significant results were found with respect to the primary endpoint, and in 13 trials (20%), this was found with respect to the secondary endpoint. Gains in OS were found in 12 trials (18%), whereas a benefit to PFS was found in 30 trials (46%). The average median OS was 23.1 months. Postprogression survival accounted for 64% of OS. Trials with crossover did not have OS as the primary endpoint. Trials that resulted in drug approval had a more pronounced gain in OS or PFS and had more patients than those without regulatory consequences. PFS was the main primary endpoint in randomized clinical trials in MBC and was significantly associated with drug approval. OS benefit was rarely achieved in trials where this was not the primary endpoint. The number of randomized patients, the primary endpoint and crossover are factors linked to regulatory requirements for approval, which should be considered in future trial designs.
authors.affiliation: Departments of aPharmacy bMedical Oncology, Hospital del Mar cIMIM (Hospital del Mar Medical Research Institute) dAutonomous University of Barcelona ePompeu Fabra University, Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Conde-Estévez
authors.forename: Ignasi
authors.initials: I
authors.lastname: Tusquets
authors.forename: Sonia
authors.initials: S
authors.lastname: Servitja
authors.forename: María
authors.initials: M
authors.lastname: Martínez-García
authors.forename: Esther
authors.initials: E
authors.lastname: Salas
authors.forename: Joan
authors.initials: J
authors.lastname: Albanell
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D017326:Clinical Trials, Phase III as Topic; D018450:Disease Progression; D018572:Disease-Free Survival; D017277:Drug Approval; D005260:Female; D006801:Humans; D009362:Neoplasm Metastasis; D016032:Randomized Controlled Trials as Topic; D017211:Treatment Failure
chemical_list: D000970:Antineoplastic Agents