A Significant Anticancer Drug Approval Lag Between Japan and the United States Still Exists for Minor Cancers.

Reports have indicated that approval lag for anticancer drugs between Japan and the United States has decreased. However, if this is also true for drugs used to treat minor cancers remains unknown. We analyzed the anticancer drugs approved in Japan from 2006 to 2016 to compare the drug approval lag based on cancer incidence (major vs. minor cancers) between Japan and the United States. The lag of anticancer drugs for minor cancers had not decreased relative to that a decade ago. Recently, development strategies resulting in longer approval lag were used by pharmaceutical companies more often for the development of drugs used to treat minor cancers than for drugs targeting major cancers, leading to significant differences in the approval lag time between drugs for major and minor cancers. Effective measures that expedite the development of drugs targeting minor cancers in Japan should, therefore, be implemented to shorten lag time.