Dr Simon Newman,
Chief Scientific Officer, NanoGenics
New delivery vehicles can help to get gene therapies to the right place in the body, making these treatments more effective, at a lower cost and with less toxicity.
Gene therapy has changed significantly over time, says Dr Simon Newman, Chief Scientific Officer at the research company, NanoGenics.
Dr Newman explained how cystic fibrosis (CF) was one of the first diseases to be targeted by gene therapy. CF is caused by a defect in a single gene, so it seems obvious that replacing the mutated gene with one that doesn’t contain the mutation will treat the patient. Since then multiple other diseases, including cancer, have been identified as potential targets for gene therapy.
Dr Newman explains that the problem with gene therapy is getting the right amount of the correct gene therapy safely into the correct cells. This problem has yet to be solved and we are still not close to a cure for even a single-gene disorder such as CF.
How can we get the gene therapy to the right place?
Gene therapies have traditionally been delivered by modified viruses. Viruses naturally deliver themselves into cells, so scientists exploit this to use viruses to deliver gene therapies.
This is risky, however. A major problem is that the body develops an immune response to the virus. This means that only one dose can be given, so there is no opportunity to tailor the course of treatment to the patient, the disease or their response. Producing safe viruses to deliver gene therapy is costly – one gene therapy for lymphoma costs around £400,000 per patient. 20-30% of patients who use this therapy (having failed all other treatments) will go into remission, but there is a significant risk of toxicity which can be fatal.
Using an artificial virus that acts as a delivery vehicle without stimulating the same immune response, allows treatment to be given more than once. It can be given directly to the place where it is needed (e.g. as an aerosol for lung disease or directly injected into the eye for glaucoma). It has a ‘lock and key’ mechanism – a ‘key’ on the surface of the artificial virus binds to a ‘lock’, which is only present on the specific cell type at which the drug is aimed. This allows the artificial virus to carry the gene therapy directly to the place in the body where it is needed.
Working together to benefit patients
This is an area where collaboration is important. Biotech and pharma companies who have gene therapies with no way of delivering them can work with companies such as NanoGenics, with the aim of using their artificial virus, LipTide to deliver the gene therapy. Work is currently underway to use this for the treatment of neuroblastoma, a rare childhood cancer. Dr Newman hopes that the eventual outcome of this will be better treatments that can be given at a lower cost with less toxicity – a result that would benefit patients and the NHS.