Advanced therapy medicinal product (ATMP) classification - a case study on spinal cord injury.

BACKGROUND: The classification of Advanced Therapy Medicinal Products (ATMPs) within the European regulatory framework poses significant challenges, particularly when biomaterials are combined with viable cells, as in spinal cord injury (SCI) therapies. Despite promising preclinical advances, many such therapies struggle to reach clinical application due to uncertainty surrounding product classification, especially in academic-led developments. MAIN BODY: This review examines the regulatory criteria and procedures for ATMP classification in the European Union, with a focus on tissue-engineered products (TEPs). It addresses common difficulties in determining the principal mode of action, degree of manipulation, and intended function—key factors that guide classification. To illustrate these regulatory considerations in practice, we present the case of 1394UA, a hydrogel derived from human amniotic membrane extracellular matrix and integrated with induced neural stem cells, developed for SCI repair under the European Neurostimspinal project. The case highlights how early classification decisions can influence quality control strategies, non-clinical study design, and clinical development pathways. CONCLUSION: Early regulatory classification is critical to reduce development uncertainty, especially for academic groups working on complex biomaterial–cell combinations. By clarifying regulatory expectations and aligning product features with appropriate ATMP designations, developers can better plan translational pathways. This review provides practical guidance to support the integration of regulatory science into early-stage ATMP development for SCI and similar applications.