Adherence of published randomised Phase 3 cancer trials to principles proposed by common-sense oncology

Randomised Controlled Trials (RCTs) should be designed rigorously, analysed appropriately, and reported accurately to enable shared decision making about cancer treatments that is aligned with patient priorities. Common-Sense Oncology (CSO) has published principles for their design, analysis, and reporting, with checklists to help ensure this.

We applied CSO checklists to 55 RCTs evaluating systemic therapies for solid tumours published in 2023 to assess the extent to which they adhered to CSO principles, and to provide a benchmark for comparison with future trials.

Progression-free survival (PFS) and overall survival (OS) were primary endpoints in 53 % and 43 % of 47 trials for advanced disease, respectively. Twelve of 55 (22 %) trials had a control arm judged to be an inappropriate standard of care at time of trial initiation, 60 % justified their selection of an alternative primary endpoint to OS, and 42 % included Health-Related Quality-of-Life (HRQoL) measures as a secondary endpoint. Only two (3.6 %) trials addressed strategies to limit censoring and dropout: numbers of censored patients were shown below Kaplan-Meier curves in 40 % of the trials, but sensitivity analysis to determine potential effects of censoring was undertaken in only 5 (9 %) trials. Persistent toxicities were reported in only one trial, and only 3 trial reports mentioned cost or cost-effectiveness.

By applying the CSO checklists systematically, we identified several deficiencies in the design, analysis, and reporting of RCTs evaluating systemic therapies for solid cancers. Our survey highlights the need for improvements in design and reporting of RCTs to enable readers to correctly interpret their results.