Comparison of reporting phase I trial results in ClinicalTrials.gov and matched publications.

Abstract

6514 Background: The 2007 Food and Drug Administration (FDA) Amendments Act mandated reporting of results of clinical trials in ClinicalTrials.gov, a large public registry, within 12 months of completion. We compared results reported for phase I trials in ClinicalTrials.gov and matched primary publications. Methods: The ClinicalTrials.Gov database was searched for completed adult phase I cancer trials with reported results. Only trials with dose escalation of systemically administered medications were included. PubMed was searched for matching primary publications, defined as identical intervention, number of arms and enrolled subjects, published prior to November 1, 2016. Results reported in the primary publication were compared with the ClinicalTrials.gov database using a 28-point score (2 = complete agreement; 1 = partial agreement; 0 = no mention) for 14-items related to study design (4 items), outcome measures (4 items) and safety profile (6 items). The ClinicalTrials.gov database was used as the reference for results reporting. Linear regression was used to identify factors associated with incomplete reporting. Results: After a review of 583 trials in ClinicalTrials.gov, 163 matching primary publications were identified, comprising 95 (58%) phase I and 68 (42%) phase I/II trials. Publications reported outcomes that did not appear in ClinicalTrials.gov in 25% of trials. Outcomes were omitted or downgraded in publications in 39% of trials. The overall median reporting score was 23/28 (interquartile range 21-25). Items that were incompletely reported in publications were: inclusion criteria (29%), primary outcome definition (26%), secondary outcome definitions (53%), adverse events (71%), serious adverse events (80%) and dates of study start and database lock (91%). Phase I (p < 0.001) and multicenter trials (p = 0.002) were associated with higher reporting scores than phase I/II and single center trials. Conclusions: Reported results in primary publications for early phase cancer trials are frequently inconsistent or incomplete compared with ClinicalTrials.gov entries. ClinicaTrials.gov may provide a more comprehensive overview of safety data from new cancer drug trials.