Potential factors correlating to the PMDA's decision to waive Japanese Phase 2 and 3 studies for oncology drugs New Drug Application in Japan.

Current status of oncology drugs approved in Japan without supporting Japanese Phase 2 and 3 clinical trial (J-P2/3) data and potential factors correlating to the decision of Japanese health agency Pharmaceuticals and Medical Devices Agency (PMDA) to waive J-P2/3 data were investigated. Approximately 15 % of 61 investigated recently-approved oncology drugs were granted a J-P2/3 waiver. Drugs that were designated as Fast Track in the United States tended to be granted a J-P2/3 waiver. The orphan drug designation in Japan was also suggested to be correlated with the decision of J-P2/3 waiver, even though the trend was not significant. Specific factors related to the clinical importance, such as the designation of US Fast Track status, may have a correlation with the likelihood of J-P2/3 waiver, suggesting that the clinical importance of the drug is common in both countries. If the key criteria used to determine the waiving of Japanese clinical trial data were clearly disclosed by the regulatory agency, the development of some clinically important oncology drugs could be further expedited.