Assessment for the timing of comprehensive genomic profiling tests in patients with advanced solid cancers

Comprehensive genomic profiling (CGP) tests have been covered by public insurance in Japan for patients with advanced solid tumors who have completed or are completing standard treatments or do not have them. Therefore, genotype-matched drug candidates are often unapproved or off-label, and improving clinical trial access is critical, involving the appropriate timing of CGP tests. To address this issue, we analyzed the previous treatment data for 441 patients from an observational study on CGP tests discussed by the expert panel at Hokkaido University Hospital between August 2019 and May 2021. The median number of previous treatment lines was two; three or more lines accounted for 49%. Information on genotype-matched therapies was provided to 277 (63%). Genotype-matched clinical trials were ineligible because of an excess number of previous treatment lines or use of specific agents were found in 66 (15%) patients, with the highest proportion in breast and prostate cancers. Many patients met the exclusion criteria of one to two or more treatment lines across cancer types. In addition, previous use of specific agents was a frequent exclusion criterion for breast, prostate, colorectal, and ovarian cancers. The patients with tumor types with a low median number (two or fewer) of previous treatment lines, including most rare cancers, primary unknown cancers, and pancreatic cancers, had significantly fewer ineligible clinical trials. The earlier timing of CGP tests may improve access to genotype-matched clinical trials, with their proportion varying by cancer type. Each relevant society needs to advocate the desirable timing of CGP testing nationwide.