Development of a regulatory strategy for the cellular therapies: an American perspective

A greater understanding in cell biology now makes it possible to cultivate, expand, and manipulate many kinds of Living cells into innovative therapies. Since 1991, the US Food and Drug Administration (USFDA) has been very active in formulating policies and procedures to guide the developers of these therapies. Without regulatory oversight, the USFDA recognized that new biotechnology-derived techniques that enhance and expand the use of cells and tissues as therapeutic products resembled a manufactured product and could have the potential for serious attendant risks. For example, the use of contaminated tissues could transmit infectious diseases such as AIDS and hepatitis. Secondly, improper handling or processing of cells and tissues could lead to contamination or damage. Finally, lack of clinical safety and effectiveness assessments for cell- and tissue-based therapeutic modalities could expose the public to adverse clinical outcomes. The USFDA has determined that these technologies would be regulated as biologics or devices requiring pre-market approval. Additionally, facilities which process cells and tissues would be required to register with the US government. Following USFDA guidance, Genzyme Tissue Repair (GTR) has applied stringent principles and practices in its approach to tissue repair in its therapeutic programs. Autologous chondrocyte implantation is an application of ex vivo cell therapy used to repair articular defects of the knee. Autologous chondrocyte implantation involves the processing and expansion of chondrocytes derived from an autologous cartilage biopsy into a therapeutically effective implant. This product was the first to receive approval under the FDA Biologics Licensing Application (BLA) Program. To date, we have successfully provided cultured chondrocytes for over 2000 patients. In a second GTR program introduced in 1987, human epidermal keratinocytes are propagated ex vivo into sheets of contiguous epithelium suitable for grafting onto wound beds of patients with massive burn injuries over larger body surface areas. Finally, the efficacy of xenotransplantation is currently being pursued by transplanting embryonic porcine ventral mesencephalon tissue into patients with advanced Parkinson's disease and Huntington's disease. This tissue encourages the regeneration of brain tissue damaged by these diseases. The USFDA believes this system of regulation for programs of this type provides a rational and comprehensive framework under which tissue processors can develop and market these products. It is meant to ensure that innovation and product development in this rapidly growing medical field could proceed unhindered by unnecessary regulation and provide physicians and patients with the assurance of safety that the public has come to expect. (C) 2000 Elsevier Science S.A. All rights reserved.