This blog is part of a series of interviews on our Top Ten Emerging Technologies 2014.
RNA-based therapeutics is highlighted as a promising new technology. What does it mean?
The idea is that you are introducing an RNA (ribonucleic acid) molecule into the body as a treatment, versus a protein or a small chemical molecule. There are two complementary paths. The more established one, which is based on a technology for which Nobel prizes were awarded a few years ago, is called RNA interference and has only been developed into late-stage clinical products in the last year.
This is done with molecules called short-inhibiting RNAs, or siRNA, pieces of RNA that, when they enter into a cell, recognize and bind to a messenger RNA (mRNA), preventing the production of a certain protein. It is a way to lower the amount of a protein being produced in a cell in a sequence-specific way.
Of course, there are many challenges. First of all, how do you get these molecules into a certain type of cell? How do you get them to bind to the target protein? How many of these cells does it take to make a difference? Does this vary between diseases?
All of these issues have been the subject of multiple academic and corporate efforts, which are now beginning to bear fruit. But what is emerging, really only in the last three years, is an altogether different branch of RNA therapeutics.
Researchers have now begun to develop full-length mRNAs as potential drugs. Researchers have figured out how to manufacture these full-length mRNAs and get them into cells in the body. Instead of inhibiting the amount of a particular protein, you actually allow a cell to make just about any protein you want.
This protein could be a drug, such as an antibody like Herceptin. It could also be used as a potential vaccine. Rather than use a dead virus or a set of antigens to cause an immune response, you would introduce the mRNA for an antigen that a cell in the body produces, and the body recognizes it as foreign and uses the body’s natural process to launch an immune response.
What kind of conditions would this mRNA treatment target?
It could target any disease where the addition of a certain protein could help treat the condition. This includes important diseases like cancer and cardiovascular disease, as well as other, rarer conditions.
Cancer can cause problems by increasing or decreasing protein production. siRNA can deal with the overproduction, and mRNAs those that decrease. This approach allows us to target many proteins for the first time. Cholesterol management similarly has proteins where increasing or decreasing them can be useful.
There are also rare disorders like Tay Sachs or cystic fibrosis that lack an important protein or its proper function – this approach offers a straightforward way to provide that missing protein or function.
This is very broad-based because it is a molecular technique that engages with important pathways, and that is not disease-specific.
Is this a treatment that cures these conditions or would it be used to manage them?
It would largely manage them; although the management of some of these diseases is the ultimate cure. We are seeing this with HIV and AIDS, many cardiovascular diseases, etc.
There are precious few drugs that are cures for anything. Infectious diseases, some viral infections – these are things where you could get rid of the infection and therefore get rid of the disease. In very few other things do you have that type of an effect. I do not believe this modality is necessarily going to be any more or less curative than the current methodologies, but it is too early to tell.
How would these treatments work in practice? Would a patient need one treatment or several?
Broadly speaking, I would say that RNA treatments will be used, depending on the disease, as a set of treatments that reduce a certain inflammation that has occurred, or any number of acute conditions. In some cases, it could be used in a chronic way, meaning every other week, or once a month, or once every three months. Again, that part is disease-specific. It is not the molecule that dictates that; it is the intervention that you need and the biology of the disease that defines need.
I can give you an example of an acute case. A recent paper showed that, based on work in animal models, damage to the heart following a heart attack could be minimized with a single dose of the mRNA to ensure continued blood supply. In that case, it is an acute intervention; you would only have one shot and you are done.
In other cases, you might inject once a week, or once a month.
And this treatment is administered through injections?
People have used these intravenously. Others have shown that you can do this through intramuscular or subcutaneous injection, and even by inhalation. I do not know how viable these will be long term in oral formulations, but I am sure people will work on that as well.
How do you expect this treatment to develop over the next few years?
I would expect the first generation of drugs that will be approved will be siRNAs. Four or five years from now, we should begin to see an additional wave of mRNA therapeutics. I fully expect as we look out beyond 10 years, there will be several large drug categories that are going to have RNA-based treatments in them, which would have been unthinkable even five years ago.
Will this eventually become a fairly common treatment or remain something for rare conditions?
Certainly, it will start treating some rare conditions, but I would say it will move pretty quickly into more common ones. This tends to be how new drug modalities get introduced into the therapeutic arsenal. The manufacturing advantage of mRNA where you can use the patient’s own body to manufacture it will, however, provide a unique advantage for treating a vast range of chronic conditions. In cancer and in serious viral conditions, such as HIV and hepatitis, you may well see RNA-based approaches, but it is too early to predict with greater precision.
What kind of potential does this have to treat cancer?
I think it has vast potential for cancer; both on the RNA interference and on the mRNA side. I think cancer is going to involve a multiplicity of approaches. It is a heterogeneous disease, but I would say that it is one of the areas where we expect to see a significant contribution from RNA therapeutics. What is exciting is that this approach gives an opportunity to go after a whole set of targets that previously could not be reached.
Noubar Afeyan is Managing Partner of Flagship Ventures and Chair of the World Economic Forum’s Global Agenda Council on Emerging Technologies. Reporting by Shane Richmond.