EMA publishes revised guideline for gene therapy medicinal products

The European Medicines Agency has published a revised guideline for applicants seeking marketing authorisations for gene therapy medicinal products. The new guideline on the quality, non-clinical and clinical aspects of gene therapy medicinal products (GTMPs) has been effective since March 2018. So far only four GTMPs have been authorised in the European Union, Glybera, Imlygic, Strimvelis and Zalmoxis, but reports of pipeline products have been queuing for space in the press this year.

The most common vector systems used for gene therapy to date have been viral vectors and plasmid DNA vectors. When these are inserted into human cells they express a transgene encoding a functional protein. Newer tools in this fast evolving field, such as microRNA, RNAi and molecular gene editing approaches such as CRISPR-Cas9, directly effect the repair, addition or deletion of a gene sequence and their use is - now reflected in the revised guideline.

The scope of the guideline has narrowed compared to its predecessor. It does not apply to medicinal products containing genetically modified cells although it does apply to the vectors used in the modification of such cells. DNA vaccines are now out of scope.

The guideline adopts a risk based approach and have been broadly welcomed by stakeholders. The American Society of Gene and Cell Therapy, for example, commented that “The guideline provides clear instructions to researchers and will certainly be incredibly valuable in the development of gene therapy medicinal products.” Other commentators agree that the guideline will provide a sound platform for early engagement with the EMA and scientific advice.

The FDA has recently issued a series of its own guidelines on the development of a range of gene therapy products and the failure of agencies internationally to pursue an internationally harmonised approach has disappointed many. The EMA has countered by pointed out that global harmonization of gene therapy products is currently not under discussion as a topic for ICH collaboration.

A separate guideline is being prepared by the EMA on investigational ATMPs.