Developing and validating a regulatory science competency framework for immune cell therapy: a mixed-methods study

Background Advanced therapy medicinal products (ATMPs), particularly immune cell therapies, present distinctive regulatory challenges due to biological variability, evolving manufacturing processes, and uncertainty throughout the product lifecycle. Existing competency frameworks for regulatory science are predominantly generalist and may not adequately capture the domain-specific competencies required for immune cell therapy. Objective To develop and validate a consensus-based competency framework for regulatory science professionals in immune cell therapy. Methods An exploratory sequential mixed-methods design was employed, comprising a multi-source literature review, preliminary expert consultation, semi-structured expert interviews, and a two-round Delphi consensus process. Experts representing academia, industry, regulatory authorities, and government/public-sector organizations participated in the preliminary consultation and interviews ( n = 11) and the Delphi consensus process ( n = 20). Qualitative data were analyzed using reflexive thematic analysis. Delphi responses were analyzed using descriptive statistics, the content validity ratio, and the item-level content validity index to assess content validity in Round 1, and retention agreement, importance, educational applicability, and measurability in Round 2. Results The final framework comprised nine core competencies and 32 sub-competencies organized into three areas: Scientific and Regulatory Foundations, Strategic Application of Regulatory Science, and Regulatory Leadership and Responsibility. High retention agreement (95%–100%) indicated the stability of the framework. Sub-competencies related to leadership, ethics, and higher-order judgment received relatively lower ratings for educational applicability and measurability but were retained because of their conceptual importance. Conclusion This study presents a domain-specific competency framework that conceptualizes regulatory competence in immune cell therapy as an integrative and adaptive capability. The framework provides a practical foundation for competency-based training, assessment, and regulatory science workforce development in immune cell therapy and related ATMPs.