Statistical analysis and sample size
EVENTS
The 3 year DFS in the SOC arm is expected to be 75%. To demonstrate non-inferiority in survival with a power of 80%, alpha of 10% (2-sided), and non-inferiority hazard ratio of 1.25 (ruling out 69.8% 3-year DFS), a sample size of 810 patients in each arm is estimated with a total of 530 events required for the analysis. As per the statistical design, 1621 patient are required to be recruited and randomised (approximately 810 per arm). Accrual will take place over 4 years across approximately 50 UK sites. An Independent Data Monitoring Committee (IDMC) will meet regularly to review the data, and particularly with regards to safety and futility. Any decision by the IDMC to discontinue the trial due to lack of efficacy will endorsed by the Trial Steering Committee (TSC).