A multicenter single-arm Phase II clinical trial of second-line FOLFIRI plus panitumumab after first-line treatment with FOLFOX plus panitumumab for initial RAS wild-type colorectal cancer with evaluation of circulating tumor DNA: A protocol study.

Maeda, Hiromichi; Nagata, Naoki; Nagasaka, Takeshi; Oba, Koji; Mishima, Hideyuki; Kato, Takeshi; Yoshida, Kazuhiro; Muro, Kei; Sakamoto, Junichi

The efficacy and safety of the continuous use of panitumumab in first- and second-line treatments for colorectal cancer (CRC) have yet to be determined. Liquid biopsy of circulating tumor DNA is capable of assessing the gene mutation status at several time-points, and could predict the efficacy of ongoing panitumumab treatment. To address these two points, a multicenter single-arm Phase II clinical trial will be conducted by evaluating the effect of FOLFIRI with panitumumab as second-line chemotherapy in patients with CRC, after failure or intolerance of first-line treatment with FOLFOX with panitumumab. The primary endpoint is the 6-month progression-free survival rate. Gene mutation status using circulating tumor DNA will be assessed at multiple time-points during the study period as one of the secondary endpoints. The observed 6-month PFS rate will be compared with the threshold 6-month PFS rate of 35% with a one-sided significance level of 10% using the binomial exact test. The target number of cases in this study is 55 patients. The study protocol was approved by the Institutional Review Board of the Epidemiological and Clinical Research Information Network (17-0601-1) and will be conducted after approval by the Institutional Review Board of each participating institute. This study is registered in UMIN (UMIN000026817, March 31, 2017). The results of the present study will be presented at related international congresses, and will be disseminated in peer-reviewed journals.