Gene editing drugs – clinical potential and important regulatory considerations

Maria Schacker and Diane Seimetz

by Maria Schacker and Diane Seimetz

Your gene editing drugs are at the forefront of science – but you are no longer the only one there and it is a challenging field! Biopharma Excellence has successfully supported multiple gene therapies including gene editing projects. Read our insights on the development and regulatory challenges associated with gene editing products and how to pave the way towards your clinical study and approval.

Until several years ago, using gene editing technologies as a tool for the development of drugs was mainly the idea of a small number of brave, sometimes even called crazy, scientists. But for game changing approaches you need the brave and crazy. In the past years the fiction of gene editing has becoming reality, largely due to the discovery of the CRISPR/Cas9 system and the recognition of its great potential not only in experimental research but also in the clinical setting.

Gene editing enables targeted modifications of the genome including selective knockout of genes, correction of mutations or precise insertion of new genetic material into specific loci. While gene editing systems have originally mainly been used by academic research groups as a tool to study the function and role of genes in a variety of diseases and developmental processes, pharmaceutical companies are now showing an increasing interest in these new technologies (1). Table 1 shows an overview of the more than 30 clinical trials using gene editing technologies that are currently registered on ClinicalTrials.gov.

Table 1: Overview of gene editing clinical trials (October 2019) // ClinicalTrials.gov was searched for clinical trials involving meganucleases, ZFNs, TALENs or CRISPR/Cas. Current status from October 2019.

The current gene editing technologies that are being used in and developed for clinical applications are already offering potential treatment strategies for a vast amount of diseases. But with continuing improvement of the gene editing “toolbox” (Figure 1), not only the number of clinical trials but also the variety of target indications is likely to steadily increase in the next years.

Our recent attendance at the 27th Annual Congress of the European Society for Gene and Cell Therapy in Barcelona with no less than 3 scientific contributions from the Biopharma Excellence team has really confirmed the potential of gene editing technologies for drug development.

Figure 1: The gene editing toolbox

Sounds great? We think so, too. But you might ask yourself “It can’t be that easy. So… what’s the catch?”.

As with any new, emerging technology, translating it to the clinic is associated with some challenges that need to be addressed. These include technical challenges, such as off-target effects and the need for improvements of the delivery systems (especially for in vivo gene editing), as well as regulatory considerations. While we are sure that most scientists are aware of the technical challenges and are already working hard to overcome them, the regulatory aspects that need to be tackled are a black box to most.

Therefore, companies often raise the question how such products should be regulated. In fact, there is limited guidance out in the public domain. Therefore, practical experience from multiple projects is key. Cathomen et al. (2) provide an overview of what regulators expect in genome editing clinical trials. However, we observe that for cell and gene therapies there often are issues in all parts of the product dossier. Challenges are there to be solved and therefore we provide solutions in Table 2.

Table 2: Important considerations during gene editing-based drug development

You can find a more comprehensive review on this topic in the recent publication by Maria Schacker and Diane Seimetz from the Biopharma Excellence team (3).

Biopharma Excellence is experienced in the development of cell and gene therapies (commonly referred to as ATMPs in the EU). We understand the unique challenges and have comprehensive expertise and a proven track record in the development of this product class.

Interested in learning more about how YOUR gene therapy and gene editing product can benefit from our expertise? Get in contact with us.


 1. Seimetz D, Heller K, Richter J. Approval of First CAR-Ts: Have we Solved all Hurdles for ATMPs? 2019;11:2155179018822781.

2.  Cathomen T, Schule S, Schussler-Lenz M, Abou-El-Enein M. The Human Genome Editing Race: Loosening Regulatory Standards for Commercial Advantage? Trends Biotechnol. 2019;37(2):120-3.

3.  Schacker M, Seimetz D. From fiction to science: clinical potentials and regulatory considerations of gene editing. Clinical and translational medicine. 2019;8(1):27.

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