Mining scientific advice reports on cell-based products: Insight into the nonclinical development program

The field of cell-based therapies for human diseases is currently evolving from promising treatment options to established therapeutic concepts. The design of the nonclinical development program for cell-based products, intended to provide a rationale for treatment and to gain insight into the safety profile, is challenging because of limitations caused by species-specificity. The elements of the nonclinical package for cell-based products were evaluated using advice reports from the European Medicines Agency database from 2013 to 2018 to identify the approach followed for nonclinical development of these products.

The number and purpose of proposed and performed in vivo studies was recorded, as well as the type and design of in vitro and in vivo studies addressing biodistribution and tumorigenicity. Subsequently, the nonclinical development program was analysed for consistency across products.

In vivo studies for cell-based therapies were primarily aimed at proof-of-concept (75/86), followed by addressing safety (64/86), biodistribution (49/86) and tumourigenicity (46/86). No animal studies were performed or proposed by sponsors or regulators for 6/86 products which contained cell types that have been studied in humans for a relatively long time. For one-third of the products in vivo biodistribution and/or tumourigenicity studies were not considered necessary. in vivo tumourigenicity studies were regarded as having limited value.

Compared to more conventional medicinal products, the nonclinical development program for cell-based products was more tailored and focused on proof-of-concept. For tumourigenicity an in vitro approach may suffice. Total omission of in vivo studies appears to be possible for products with sufficient clinical experience.