Who wants to go first? A simulation study of accrual in a stand-alone trial versus starting a platform trial.

Others have quantified the efficiency of the platform approach as compared to a sequence of independent two-arm trials and have shown the platform approach more efficiently evaluates a set of candidate therapies. However, a practical barrier to initiating a platform trial is incentivizing the first candidate therapies to enter the platform. A platform trial is more complex and will take longer to design and operationalize than a traditional trial. For the first therapy, this additional up-front planning time must be considered along with the ability to enroll. There is a common concern that accrual in a platform setting would take longer than for a single stand-alone trial because intuition suggests that a two-arm trial with a smaller total sample size should complete accrual more quickly than a multi-armed trial. We focus on the accrual duration for the first therapy as a particular barrier to initiating a platform trial strategy. We simulate accrual into a platform trial versus a stand-alone trial in the setting of a large clinical trial network. Accrual duration in the platform strategy dominates that of a single stand-alone trial if the platform leverages a large enough fraction of the site network. Patient preference for a particular stand-alone trial has little impact on the ability of a stand-alone trial to enroll more quickly.