RNAs are of interest in many medical fields. However, to fully understand their value and bring them to patients we need to be able to produce them. RNA bioproduction is at the crossroads between technological issues and industrial policy.
The last few months have shown that we are capable of delivering billions of doses of messenger RNA (mRNA) vaccines. This might lead us to believe that the production systems for these biological molecules are ready. However, in reality, this is not the case. New manufacturing capacities need to be anticipated: more and more clinical trials are evaluating RNAs in medical applications, for example in cancerology, as a treatment for emerging diseases or genetic diseases. These are mRNAs, as in the case of vaccines against Covid-19, or other types of RNAs, antisense or effectors, which block or activate biological processes. Therapeutic interest in these molecules is growing rapidly and production tools and technologies need to keep pace.
To appreciate the issues at stake, it is important to look at production process. RNAs are synthesised in vitro using a DNA template and an enzyme: RNA polymerase. The RNA is then purified on chromatography columns, which take advantage of chemical properties (pH or affinity) to separate the components of the solution and isolate the product of interest. Finally, the RNA molecules are associated with vectors, i.e. envelopes that protect these fragile molecules and facilitate their entry into the cell when the RNA drug is administered.
In short supply
In order to produce pharmaceutical grade RNA, all these steps must be certified as Good Manufacturing Practice (GMP). This standard is based on a large number of controls to ensure patient safety, starting with the production of template DNA. Globally, there are very few manufacturers able to perform this step in accordance with GMP standards and none are located in Europe. The main producers of GMP DNA templates are in the US and it takes many months to get access to the desired DNA. Globally, there is therefore a high demand for this product that is in short supply, a situation which has been exacerbated by the covid-19 pandemic. In response, the Resilience part of the France Relance recovery plan* has provided the Besançon-based company RD Biotech with €2 million in for the construction of a new GMP standard DNA production site of over 1,000 m².
There are also supply issues concerning access to the enzyme, RNA polymerase, which reads the DNA template in order to synthesise RNA. However, Enzyme production is well controlled, and the pharmaceutical industry therefore tends to internalise it to secure its supply.
Finally, these processes require a large number of consumables (filter, plastic bag, etc.). The major producers of these materials are also outside Europe and there is currently a market shortage when it comes to these products. In response to the health crisis, manufacturers are now organising themselves in order to avoid supply disruptions in the event of further border closures. For example, the Merck company is going to set up a new production unit for sterile bags, necessary for the production of vaccines, in Molsheim in Alsace.
Industrial research is preparing new processes in parallel with these short-term adjustments. The plan is to move from in vitro production (enzymatic synthesis) to in vivo production, by using yeast to produce the RNA. This strategy has many advantages. Firstly, it avoids the need to produce RNA polymerase, which is naturally produced by yeast. Secondly, it limits the industrial risks associated with the use of very large volumes of highly explosive ethanol during the production process. Thirdly, as the cells are equipped with multiple systems to improve the accuracy of the transcription (by lowering the error rate inherent in each RNA polymerase), the RNA produced will be of higher quality. It will also be possible to produce longer RNAs and to develop increasingly complex applications such as multivalent vaccines, notably with vaccines directed against different flu variants. Finally, in vivo production will allow modifications to be made to the molecule after it has been synthesised, still in the yeast cell. These modifications can, for example, ‘humanise’ the biomolecule and thus increase its lifespan and effectiveness in human cells.
In vivo production systems such as this one are being developed in France as part of a collaborative programme supported for which Grand Défi “Biomedicines: improving yields and controlling production costs” has provided €1.4M of support. This research programme led by Chantal Pichon (Univ. d’Orléan) at the CNRS Molecular Biophysics Centre, in partnership with INSERM, INRAe, and the Polythéragène and Sanofi-Pasteur companies, is expected to reach industrial maturity in three to five years. The French pharmaceutical giant has also shown its willingness to develop its RNA production by acquiring the American biotechnology company Translate Bio. It plans to set up an RNA production unit at its Marcy-l’Étoile site in the Lyon region.
A sustainable price
Other avenues of research combine a medical and economic advantage. They focus on addressing therapeutic molecules, i.e. the precision with which RNAs reach the patient’s target cells. By reducing the dispersion of the molecules in the body, the risk of side effects from the treatments is reduced. It also reduces the effective dose, and therefore the total cost of treatment.
The price of biotherapies and therefore of RNA is a major issue. In the case of anti-covid vaccines, the doses of RNA required are small. Larger quantities of biomolecules will be needed for cancer applications. As is often the case with biomedical innovations, it will be a question of finding a balance between the financing of pharmaceutical research, production costs and the accessibility of products for all. The global pharmaceutical market as a whole is currently worth more than $1,300bn. If the new biotechnologies covered all needs, this market would be worth $4,800bn, which is not sustainable for our health systems. The pharmaceutical industry is aware that it will not be able to sell innovative therapeutic products tomorrow if this trend continues. The financial issue is therefore critical to the success of future of biotherapies.
To meet this challenge of accessibility to innovative therapies, the research community and industry are working to develop technologies with more economical production while guaranteeing patient safety. France wants to be a major player in this sector and the State supports this sector within the framework of its Strategy for Accelerating Biotherapies and Bioproduction of Innovative Therapies financed via the Future Investment Programme and announced by the President of the Republic during his speech on the Health Innovation 2030 plan.
* The France Recovery Plan is a set of investments, to the tune of €100bn, supported by the European Union with funding of approximately €40bn, deployed by the Government since 2020 around three components: ecological transition, competitiveness and cohesion. This plan was set in motion with a view to rapidly reviving the economy and obtaining results in terms of decarbonisation, industrial reconquest, and the strengthening of skills and qualifications throughout the country.