The largest numbers of trial terminations occur at phase II, especially if the trial is for a marketed therapy compared with a novel drug, according to an expert analysis in the Good Clinical Practice Journal.
Authors Christine Blazynski and Tracy DeGregorio analyzed aborted phase II trials to assess the reasons and strategies behind companies’ decisions to end the research. They found that companies were quicker to pull the plug on a poorly enrolling trial of a marketed drug because the drug was not dependent upon the trial for time to market (GCPj 15, 2008).
The authors found two major drivers of trial termination: company-controlled and trial-related. A company may choose to end a trial because of a change in internal drug strategy or pipeline reprioritization. A trial may also come to an abrupt end if enrollment is deemed too slow.