Masterstudiengang "Drug Regulatory Affairs"

Master-Thesis

Specific regulatory requirements for stem cell-based therapies ***

Dr. Jens Schletter (Abschlußjahr: 2002)

Currently, a new therapeutic approach fundamentally distinct from chemical, biological or biotechnologically derived drugs is emerging: cell- and tissue-based products. However, the demand for human cells, tissues and organs in most cases greatly exceeds the supply. The enormous potential of cell- and tissue-based products only has a chance to be adequately exploited if a reliable source of cells/tissues is identified.
The most promising approach to meet this demand is the use of stem cells, largely due to their unique characteristics: under specific conditions they have the ability to either proliferate for extended periods of time or to differentiate into specialized cells that make up the tissues and organs of the body.

The development of stem cell-based therapies is an extraordinarily complicated process with unique regulatory challenges. Therefore it is crucial to pay close attention to regulatory affairs issues from the very onset of any project ultimately aimed at developing stem cell therapeutics.
The regulatory requirements differ, depending on the source of the stem cells: several types of stem cells are available with different characteristics, influencing their potential therapeutic value. In most cases an allogeneic approach (patient treated with cells derived from other human source than himself) will be advantageous or will even be the only realistic option.

The legal base and general classification considerations regarding stem cell-based products in the USA, the EU and Germany are presented. Such products will have to undergo review and approval procedures by regulatory authorities in the USA as well as in the EU before entering clinical trials as well as prior to market approval. Most likely, the majority of stem cell-based products will be regulated as biologics in the USA and as medicinal products in the EU. Although there might be uncertainties in the details, it is obvious that appropriate quality, safety and efficacy of these products has to be shown.
Particular regulatory challenges will include the use of embryonic stem cells, the issues of gene therapy and xenotransplantation and the allogeneic nature of the treatment.
The regulation of stem cell-based therapies is more fragmented in the EU as compared to the situation in the USA. Furthermore, responsibility for regulation of stem-cell based research rests within the national level of the member states, leading to a regulatory diversity reflecting the pluralism in ethical, religious and political opinions.

The unique characteristics of stem cell-based products result in very particular regulatory challenges during manufacturing, preclinical and clinical testing. Currently there is no specific guidance on the development of such therapies. However, at least some of the current regulations were found to be applicable in generic form. Based on existing guidelines, publications from the NIH and the USP, previous experience with cell-based products and activities of regulatory authorities, critical regulatory issues are identified and recommendations are given for the development of a stem cell-based product until clinical entry.

An early and ongoing contact with the regulatory authorities will be mandatory for successful development: The whole development process should be accompanied by continuous interactions between the respective pharmaceutical/biotech company and the regulatory agencies. Due to the differences in regulation and experience among the various regulatory agencies, the FDA, especially CBER, will be of particular importance in this field.

Once the technical and regulatory hurdles are mastered, this would enable not only access to just one product but lead to tremendous synergies for follow-up developments.

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