A design alternative for two-stage, phase II, multicenter cancer clinical trials.

Data are reviewed upon completion of patient accrual to the first stage of a two-stage phase II cancer clinical trial and prior to initiating accrual on the second stage. Often accrual must be suspended while the data from the first stage are collected and evaluated. In an effort to maintain patient accrual momentum and avoid the logistical problems of suspending and reactivating a multicenter study, an alternative approach to conducting two-stage phase II studies, which allows patient accrual to continue while the results of the first stage are reviewed, is proposed. The properties of the proposed design are examined.