Clinical Trial Complexity Levels Show Unrelenting Increase

It might not be too big of a surprise to those toiling in the clinical trial fields, but a new study confirms what many probably suspected already: Trials are getting more complex.

Increasing complexity of clinical trials targeting cancer—including use of more sophisticated scientific designs, larger global scope, and greater focus on highly targeted patient subpopulations—have intensified the challenges in executing those trials, a newly completed analysis by the Tufts Center for the Study of Drug Development (CSDD) concludes.

“Oncology is the fastest growing and most active area of drug development, which also has led to more [new product] approvals,” said Ken Getz, professor and director of Tufts CSDD, who oversaw the study. “But the high and growing number of oncology drugs in the pipeline and entering the market belies the substantial risk and major executional challenges associated with cancer therapy development, which are likely to further intensify.”

From 2000 to 2020, the number of investigational treatments targeting cancer has nearly quadrupled, from 421 to 1,489, according to Tufts CSDD. At the same time, Phase II and Phase III oncology trials typically entail more investigative sites across more countries compared to trials for other drugs, which makes it more difficult to find, compete for, and enroll patients.

“The welcomed news is that regulatory review durations for oncology drugs are two and a half months shorter, on average, than for other drugs,” Getz said, noting that in the United States oncology drugs are more than twice as likely to receive priority review status.

Study results, highlighted in the May/June Tufts CSDD Impact Report, also found:

  • Clinical trial durations for oncology drugs are 30% to 40% longer than for other drug trials, due to more complex designs and difficulty finding, enrolling, and retaining study volunteers.
  • Screening and treatment durations are much longer in Phase II and III oncology trials, compared to other drug trials, but mean study start-up times are shorter in Phase III.
  • Oncology trials generate a much higher volume of data, particularly in Phase II protocols, compared to other drug trials.
  • Phase II and III oncology trials, compared to trials for other drugs, have more protocol deviations and generate more substantial protocol amendments.

Edited by Michael Causey