The United States Food and Drug Authority (FDA) has just given the green light to America’s first ever gene therapy treatment. It’s called Kymriah and it’s a genetically-modified autologous T-cell immunotherapy (CAR-T cell therapy). For the layman: individually customised, cancer-killing white blood cells. This is why it’s a big deal, and what the future could hold for us here in Australia.
Let’s start with the basics. The FDA does a good job of summing up what “gene therapy” actually is:
“Human gene therapy refers to products that introduce genetic material into a person’s DNA to replace faulty or missing genetic material, thus treating a disease or abnormal medical condition.”
Scientists only started attempting to edit DNA in 1980, and the first therapeutic trials were performed in the early 1990’s.
Since then, researchers have tested several applications of gene therapy including:
- replacing mutated genes with healthy copies of the gene;
- inactivating a mutated gene that is functioning improperly; and
- introducing a new gene into the body to help fight a disease.
“New frontier” for cancer treatment
Kymriah is a form of gene therapy developed by Swiss pharmaceuticals giant Novartis to treat acute leukaemia in young people. The therapy uses the patient’s own blood cells to fight the disease.
The FDA has described the procedure as historic: “We’re entering a new frontier in medical innovation with the ability to reprogram a patient’s own cells to attack a deadly cancer.”
The idea is that the patient’s white blood cells are collected and sent to a manufacturing centre where they are genetically modified to include a new gene that contains a specific protein (a “chimeric antigen receptor” or CAR) that directs the T cells to target and kill leukaemia cells. Once the cells are modified, they are infused back into the patient to get to work and fight the cancer.
In one multi-centre clinical trial of 63 patients the overall remission rate within three months of treatment was 83%.
Kymriah is intended for patients who have few options left, often because they have not responded to initial treatments or because they have relapsed.
It’s an incredible treatment, and holds a lot of promise, but it’s not all good news. There are some significant drawbacks to the new treatment. The FDA has advised that the treatment can carry some serious side effects, such as life-threatening fever and flu-like symptoms, as well as neurological issues.
It’s also expensive. Really expensive. Novartis has said that it will charge US$475,000 for the treatment. That is a lot of cash, but given the complexity of the procedure, it was reportedly cheaper than many analysts had expected.
Ready to go
The approval by the FDA means that the therapy will be available to patients under 25 years old in a small number of specially certified hospitals around the US. Novartis has been in a race to approval with its rivals Kite Pharma and Juno Therapeutics, who are developing similar treatments.
What about Australia?
This particular kind of gene therapy is not available in Australia at the moment. Given the current costs and risks associated with the therapy, it may be some time before we see a similar domestic approval.
Before they become available, gene therapies have to be tested in clinical trials and approved as “biologicals” by the Therapeutic Goods Administration. This process involves being assessed in accordance with the various controls that apply specifically to biological medical products. To receive government subsidies, gene therapies would also have to be listed on the Pharmaceutical Benefits Scheme.
The first clinical trials of similar immunotherapy treatments have just begun. In August 2017, the Westmead Institute for Medical Research (WIMR) and Westmead Hospital launched a two year clinical trial to test a new form of CAR-T therapy in leukaemia patients.
The TGA oversees clinical trials undertaken in Australia. The Therapeutic Goods Act 1989 (Cth) sets out different schemes for conducting trials, and ethics committees have close involvement at each stage of the trial process.
Australia also has legislation dealing specifically with gene technologies, the Gene Technology Act 2000 (Cth). The GT Act sets up a Gene Technology Regulator, as well as a Technical Advisory Committee. Depending on the kind of genetically modified product that will be used in a clinical trial a licence approvals may required from the Regulator.