Dynamic change in the distribution of cancer types in oncology phase I trials
Authors: J. Sato, K. Itahashi, T. Shimizu, T. Koyama, S. Kondo, Y. Fujiwara, N. Yamamoto
Journal: Annals of Oncology (2019)

Background: Insufficient information is available on cancer types among patients enrolled in all-comer phase I oncology trials. We evaluated the global trends in cancer types of patients in these trials, including time-dependent changes and regional differences among North America, Europe, and Asia. Methods: The PubMed database was searched to identify single-agent phase I trials published between 1991 and 2015, which enrolled patients with any type of solid tumor. The inclusion and exclusion criteria were predefined for article selection; trials recruiting from specific patient populations were excluded from the analysis. Results: We identified 866 eligible clinical trials, which enrolled a total of 29,112 patients with advanced solid tumors. The selected trials were conducted mainly in North America (55.5%), Europe (27.8%), and Asia (10.5%). The distribution of cancer types in phase I trials was considerably different from cancer-related incidence and mortality. Colorectal cancers (n = 7,510, 25.8%) were the most prevalent in phase I trials, followed by lung cancer (n = 3,212, 11.0%), sarcoma (n = 1,756, 6.0%), breast cancer (n = 1,623, 5.6%), renal cancer (1589, 5.5%), and ovarian cancer (1473, 5.1%). The proportion of patients with either colorectal or lung cancer decreased with time. The proportion of trials, in which patients with either of these two cancers accounted for ≥50% of the total enrolled patients in each trial, had also decreased as follows: 31/67 trials (46.3%) from 1991 to 1995, 58/142 (40.8%) from 1996 to 2000, 59/223 (26.5%) from 2001 to 2005, 38/189 (20.1%) from 2006 to 2010, and 41/245 (16.7%) from 2011 to 2015. These trends were consistent across the three regions, with an increase in the proportion of various types of cancer enrolled in phase I trials. Conclusions: The distribution of cancer types among patients enrolled in all-comer phase I trials has changed dramatically. Patients with common types of cancer, with poor general condition and vital organ dysfunction after multiple lines of therapy, are likely not to participate in phase I trials. Legal entity responsible for the study: Noboru Yamamoto. Funding: Has not received any funding. Disclosure: T. Shimizu: Consulting: Takeda Oncology; Honoraria: ONO, ONO Pharma Taiwan, Boehringer Ingelheim, Taiho, Chugai; Research funding: Takeda Oncology, PharmaMar, BMS Japan, Daiichi Sankyo, SymBio, Five Prime Therapeutics, 3D Medicine. S. Kondo: Research funding: AstraZeneca, Eli Lilly, Pfizer. Y. Fujiwara: Consulting: ONO, BMS Japan; Participation in speakers' bureau: ONO, BMS Japan, MSD, Taiho; Research funding: AstraZeneca, Chugai, Daiichi Sankyo, Eisai, Lilly Japan, Novartis, BMS Japan, MSD, Merck Serono, Abbvie, Incyte. N. Yamamoto: Consulting: Eisai, Takeda, Otsuka, OncoTherapy; Speakers' bureau: BMS, Pfizer, AstraZeneca, Lilly, ONO, Chugai; Funding: Chugai, Taiho, Eisai, Quintiles, Astellas, Novartis, Daiichi Sankyo, Boehringer, Takeda, Kyowa Kirin, Bayer, Pfizer, BMS, ONO. All other authors have declared no conflicts of interest.