The authors go on to report that: ‘The data and safety monitoring board inspected the planned adaptive interim analysis on the primary endpoint, and recommended that the sample size be increased to...

The authors go on to report that: ‘The data and safety monitoring board inspected the planned adaptive interim analysis on the primary endpoint, and recommended that the sample size be increased to 180 patients per group to achieve a conditional power for significance of 80%’. The results were that: ‘22 (12%) of 180 participants in the defibrotide group had veno-occlusive disease by 30 days after HSCT compared with 35 (20%) of 176 controls (risk difference –7.7%, 95% CI –15.3 to –0.1; Z test ...p= 0.048 8 . . .)’. The 95% confidence intervals for the proportions with veno-occlusive disease were 7% to 17% for the defibrotide group and 14% to 26% for the control group.