Patient enrolment is the main driver behind sharp increases in the cost of oncology clinical trials between Phases II and III, a new study has found.

Analysts at Cutting Edge Information identified a strong correlation between patient enrolment and total cost in the 29 oncology trials they looked at for the study, “Oncology Clinical Trials: Drug Development Resources and Case Studies”.

On average, the total cost of Phase III oncology trials was four times higher than that of Phase II studies, the analysts noted. On a per-patient basis, though Phase III trials cost only 7% more than Phase II studies.

The discrepancy lies in the much higher levels of patient enrolment required for Phase III trials, which can be 400% more than in Phase II, the analysts explained.

Per-patient costs

As a point of comparison, the average per-patient cost of Phase I oncology trials was found to be US$45,200.

“The low number of required patients in Phase 1 compared to later stages limits the number of investigator sites and operations staff needed — lowering per-patient costs,” the analysts pointed out.

The rise in average per-patient costs between Phases II and III for the oncology trials reviewed by Cutting Edge Information was about US$5,100.

This is largely due to increased staffing levels and other clinical-infrastructure adjustments, such as upgrades to data management and trial supplies, that may be needed to accommodate the leap in enrolment numbers between the two phases, said senior research analyst Ryan McGuire.