Motivation
EVENT, RECRUITMENT
If recruitment is rather slow, as in many single-arm phase II trials, it is likely the interim data contains information not only on the short-term assessments of the endpoint but also on later assessments or even the long-term outcome, either because some patients already had the event and hence cannot be event-free at the long-term endpoint or because they have been observed for so long that their long-term outcome is known. This information cannot be used in Kunz’s design for the interim decision. In contrast, our new methods incorporate this information to evaluate the CP or the PoS in the interim analysis, while still allowing for the same reduction of delay (compared to Simon’s design) due to the interim analysis as Kunz’s design. The trial will continue only if the CP or the PoS are sufficiently large in an interim analysis, which can be conducted at any (prespecified) point of time during the trial.