Funding Support and Principal Investigator Leadership of Oncology Clinical Trials Using Radiation Therapy

Abstract

Sources of funding and principal investigator (PI) leadership for clinical trials using radiation therapy (RT) are not well characterized but are important mediators of innovation, particularly because funding for trials from the National Institutes of Health (NIH) has decreased and industry funding has increased. We sought to determine characteristics of trials using RT that are associated with industry funding, NIH funding, and radiation oncologist (RO) PI leadership. www.ClinicalTrials.gov was queried for all open, interventional trials that administered RT. Logistic regression was used to identify associations between trial characteristics, receipt of funding type (NIH, industry, or other), and PI leadership. The authors identified 1469 oncology trials, of which 41% were based in the United States, 56% were based internationally, and 3% were based in the United States and internationally. Of these, 22% were RT monotherapy, 53% were bimodality (40% RT + drug, 13% RT + surgery), and 24% were trimodality. Although ROs led 60% of all trials, industry-sponsored trials were significantly less likely to have RO PIs (35% RO vs 65% non-RO PI; adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.28-0.73), to fund trials that did not incorporate drug therapy (aOR, 0.19; 95% CI, 0.10-0.35), or to fund phase III trials (aOR, 0.25; 95% CI, 0.11-0.60) because industry-sponsored trials favored smaller phase I trials. NIH-funded trials were not associated with PI type and, although not statistically significant, favored larger phase III trials (unadjusted OR, 2.06; 95% CI, 0.99-4.29). ROs were less likely to lead trials incorporating drug therapy (aOR, 0.30; 95% CI, 0.22-0.41). ROs are less likely than other specialties to lead trials that use RT in combination with drug therapy or surgery and more likely to lead trials supported by nonindustry, non-NIH funding. This suggests a need for ROs to lead multimodality trials and to consider opportunities to interact with industry. As NIH resources decrease, alternative funding is needed to support innovation, particularly in in RT-alone trials.