Statistical analysis
The STREAM study design was developed according to Simon’s two-stage optimal design, to minimize the number of patients exposed to a possibly inactive drug, considering that alternative treatment options existed, although not satisfactory and likely to be more toxic.Setting type I and II errors at 10% to test the null hypothesis that the rate of patients alive without progression at 6 months was 30% or less versus the alternative hypothesis of 50% or more, 22 assessable patients were required in the first stage. If eight patients were alive without progression after 6 months, a further 24 assessable patients would have been enrolled in the second stage for an overall sample size of 46 assessable patients. The study would have been considered positive if at least 18 patients out of 46 were alive without progression at 6 months.Differences between categorical data within subgroups were measured using parametrical tests, χ