Impact of expedited programs in the United States, as foreign regulatory factors, on clinical development time in Japan.

What Is Known And Objective: Regulatory authorities in several regions have introduced a number of expedited programs (EPs) to promote the development of innovative drugs for patients in their own countries. The EPs in the United States (US), alone or in combination, have been successful in shortening the clinical development time in the US. We examined whether US-EPs, as well as other related factors, have an impact on the clinical development time in Japan to obtain new insights for more efficient drug development.

Methods: In total, 168 drugs approved as new molecular entities (NMEs) in Japan and approved in the US between 2012 and 2019 were surveyed. We compared the clinical development time in Japan for those drugs with or without US-EPs. We also examined the impact of overlapping designations of US-EPs on clinical development time in Japan. Multiple regression analysis was performed to identify associated factors related to clinical development time in Japan, including US-EPs.

Results And Discussion: The clinical development time in Japan was significantly shorter at 37.4 [Interquartile range, IQR, 28.7-48.9] months for Accelerated Approval (AA), 42.2 [30.0-53.6] months for Breakthrough Therapy (BT), 42.3 [29.3-56.4] months for Fast Track (FT), 44.5 [30.7-60.0] months for US Priority Review, and 45.2 [31.3-61.8] months for US Orphan Designation. Multiple regression analysis revealed that AA (p = 0.008), FT (p = 0.013), Japan Priority Review, and the difference in development initiation dates between the US and Japan were significant factors related to a decrease in the clinical development time in Japan, whereas Japan Orphan Designation and the development of anticancer drugs were significant factors linked to an increase in the clinical development time.

What Is New And Conclusion: US-EPs were associated with a decrease in the clinical development time in Japan for the drugs that were approved as NMEs in Japan and approved in the US. This association was not restricted to particular therapeutic areas or development strategies. Stakeholders involved in drug development, including the drug developers and regulatory authorities in Japan, should realize these effects for efficient drug development.