Factors Associated with Inclusion of Japan in Phase I Multiregional Clinical Trials in Oncology

Early inclusion of Japan in the global development program could be a key factor in reducing the drug lag, making participation in phase I multiregional clinical trials (Ph. I MRCTs) an important consideration for oncology drug development in Japan. We aimed to investigate the factors associated with the inclusion of Japan in Ph. I MRCTs in oncology.

We compared the trial design, target population, type of primary tested drug, trial conduct profile, and sponsor profile for Ph. I MRCTs with or without Japan conducted by the top 20 companies in more than two countries and started between January 1, 2011, and December 31, 2020.

One hundred and ninety-seven Ph. I MRCTs included Japan, and 697 did not. Detailed features of the Ph. I MRCTs in oncology were summarized, and several factors (trial design, target population, trial conduct profile, and sponsor profile) associated with inclusion of Japan in the Ph. I MRCTs were identified.

It is important for Japanese subsidiaries within global pharmaceutical companies to closely communicate with the headquarters based on medical practice and unmet needs in Japan to join global development from an early stage. In addition, further efforts to attract emerging biopharmaceutical companies to Japan from the regulatory and/or political perspectives would be needed, thereby preventing drug lag in Japan.