The ability to track therapeutic cells upon administration to the patient is of interest to both regulators and developers of cell therapy. The European Commission Horizon2020 project nTRACK from 2017-2022 aimed to develop a multi-modal nano-imaging agent to track therapeutic cells during development of a cell therapy. As part of this project, we investigated the regulatory pathway involved for such a product. An important regulatory hurdle appeared to be the appropriate regulatory classification the nTRACK nano-imaging agent, as neither the definition for medicinal product nor the definition for medical device were a good fit for the purpose of the product. As a consequence, the information requirements to fulfill before conducting a First in Human trial are not evident and can only be decided upon by closely collaborating and communicating with the relevant authorities throughout the development of the product. Moreover, standard test methods for demonstrating the quality and safety of a medicinal product or medical device are not always suitable for nanomaterials such as the nTRACK nano-imaging agent. Regulatory agility is therefore a great need to prevent delay of promising medical innovations, although regulatory guidance on these products will likely improve with more experience. In this article, we outline the lessons learnt related to the regulatory process of the nTRACK nano-imaging agent for tracking therapeutic cells and offer recommendations to both regulators and developers of similar products.

The ability to track therapeutic cells upon administration to the patient is of interest to both regulators and developers of cell therapy. The European Commission Horizon2020 project nTRACK from 2017-2022 aimed to develop a multi-modal nano-imaging agent to track therapeutic cells during development of a cell therapy. As part of this project, we investigated the regulatory pathway involved for such a product if marketed as a stand-alone product. An important regulatory hurdle appeared to be the appropriate regulatory classification of the nTRACK nano-imaging agent, as neither the definition for medicinal product nor the definition for medical device appeared to be a good fit for the purpose of the product and we were confronted with diverging views of competent authorities on the classification. As a consequence, the information requirements to fulfill before conducting a First in Human trial are not evident and can only be decided upon by closely collaborating and communicating with the relevant authorities throughout the development of the product. Moreover, standard test methods for demonstrating the quality and safety of a medicinal product or medical device are not always suitable for nanomaterials such as the nTRACK nano-imaging agent. Regulatory agility is therefore a great need to prevent delay of promising medical innovations, although regulatory guidance on these products will likely improve with more experience. In this article, we outline the lessons learnt related to the regulatory process of the nTRACK nano-imaging agent for tracking therapeutic cells and offer recommendations to both regulators and developers of similar products. Graphical Abstract