Quality of reporting in oncology phase II trials: A 5-year assessment through systematic review

BACKGROUND: Phase II clinical trials are a cornerstone of the development in experimental treatments They work as a "filter" for phase III trials confirmation. Surprisingly the attrition ratio in Phase III trials in oncology is significantly higher than in any other medical specialty. This suggests phase II trials in oncology fail to achieve their goal. Objective The present study aims at estimating the quality of reporting in published oncology phase II clinical trials. DATA SOURCES: A literature review was conducted among all phase II and phase II/III clinical trials published during a 5-year period (2010–2015). STUDY ELIGIBILITY CRITERIA: All articles electronically published by three randomly-selected oncology journals with Impact-Factors>4 were included: Journal of Clinical Oncology, Annals of Oncology and British Journal of Cancer. INTERVENTION: Quality of reporting was assessed using the Key Methodological Score. RESULTS: 557 articles were included. 315 trials were single-arm studies (56.6%), 193 (34.6%) were randomized and 49 (8.8%) were non-randomized multiple-arm studies. The Methodological Score was equal to 0 (lowest level), 1, 2, 3 (highest level) respectively for 22 (3.9%), 119 (21.4%), 270 (48.5%) and 146 (26.2%) articles. The primary end point is almost systematically reported (90.5%), while sample size calculation is missing in 66% of the articles. 3 variables were independently associated with reporting of a high standard: presence of statistical design (p-value <0.001), multicenter trial (p-value = 0.012), per-protocol analysis (p-value <0.001). LIMITATIONS: Screening was mainly performed by a sole author. The Key Methodological Score was based on only 3 items, making grey zones difficult to translate. CONCLUSIONS & IMPLICATIONS OF KEY FINDINGS: This literature review highlights the existence of gaps concerning the quality of reporting. It therefore raised the question of the suitability of the methodology as well as the quality of these trials, reporting being incomplete in the corresponding articles.