In the current pharmaceutical environment, where the industry faces a potential patent cliff ranging anywhere from $236–400B in revenue,1,2 sponsors are under mounting pressure to hit increasingly aggressive milestones. Yet many programs underestimate the operational realities that shape recruitment and retention, particularly in competitive therapeutic areas like oncology or rare diseases. A growing body of research confirms this disconnect: nearly 80% of clinical trials fail to meet initial enrolment targets on schedule, and around 19% are terminated early due to insufficient accrual.3,4 Overall, only 40% of clinical trials reach their intended enrolment goals.5 Even when enrolment succeeds, retention presents a second major hurdle. It’s not unusual for dropout rates in trials to be as high as 25–30%,6 compromising both data integrity and statistical power. In long-term trials, these rates can rise even higher, especially when patients perceive limited therapeutic benefits.

In short, patient recruitment and retention represent major operational risks to successful oncology study completion generally, and in particular, for complex and competitive therapeutic areas. Our experience confirms these trends, and more importantly, sheds light on their root causes and potential solutions.