New Drug Development Strategy in Japan: Flexibility in Guideline Adherence

Area of Science:

• Pharmaceutical Development
• Regulatory Science
• Clinical Trials

Background:

• A "drug lag" phenomenon, termed "drug loss," is emerging in Japan, where drugs approved elsewhere are not initiated for development.
• This lag may stem from Japanese guidelines requiring local clinical trial data, posing challenges for foreign biopharma companies.
• Understanding adherence to these guidelines is crucial for addressing development delays.

Purpose of the Study:

• To investigate Japanese guideline adherence for new drug applications.
• To identify factors influencing flexibility in clinical data requirements for foreign drug developers.
• To inform strategies for mitigating drug lag in Japan.

Main Methods:

• Analysis of clinical data packages for 159 drugs approved in Japan (April 2019 - March 2024).
• Examination of pharmacokinetic (PK) and efficacy/safety data from Japanese participants.
• Identification of flexible development approaches and associated drug characteristics.

Main Results:

• Nearly all approved drugs included Japanese PK and efficacy/safety data.
• Flexible approaches observed: absence of Japanese dose-response data (39.6%), phase III data (35.2%), and post-hoc PK data (43.0%).
• Biologics, orphan drugs, antineoplastics, and originator companies showed significant association with flexibility.

Conclusions:

• While Japanese data is generally included, flexibility exists in specific trial phases and data types.
• Factors like drug type and designation influence the degree of flexibility.
• These findings can guide foreign companies in developing strategies to accelerate drug development in Japan.