Gene therapy is a treatment that replaces defective, down-regulated or missing genes with normal genes, enabling cells to function the way they are meant to. Gene therapy can also be used to introduce a new gene into the body, in an attempt to cure or improve its ability to fight disease. This technique – the process of which is known as gene transfer – is one day expected to allow doctors to treat a disorder by using genes instead of drugs or invasive surgery. Today, researchers are testing several approaches to gene therapy, including:
- Replacing a mutated, disease-causing gene with a healthy version of the gene
- Inactivating a mutated gene that is not functioning properly
- Introducing a new gene into the body to help fight a disease
Gene therapy holds the promise of disrupting the disease process with a single administration. A successful treatment relies on finding a dependable delivery mechanism to carry the correct gene to the defective cells. The gene must be delivered inside these target cells. The effect of gene therapy at the cellular level cascades to an effect on tissue-, organ- and system-wide physiology, resulting in an improvement of normal body processes. Delivering genes that will work correctly for the long term is one of the greatest challenges of gene therapy, but progress in the field is promising.
Clinical development of gene therapy began more than 25 years ago. More than 2400 gene therapy clinical trials have been conducted since 1989, with more than 320 gene therapy clinical trials currently ongoing. The European Commission approved the first-ever gene therapy in the Western world in 2012. The history of gene therapy has been a combination of promise and disappointment, but continued research is indicating that a new era of medicine is on the horizon.
At Renova Therapeutics, our gene therapy efforts are focused on chronic diseases. The first two indications the company is pursuing are gene therapies for congestive heart failure and type 2 diabetes, two of the most common and devastating chronic diseases in the world.
GENE THERAPIES VERSUS SMALL-MOLECULE DRUGS: A QUICK COMPARISON
- Unlike small-molecule drugs (e.g. pills), which work to minimize disease symptoms by decreasing demands on the body, successful gene therapy treatments work to significantly improve – in some cases, normalize – defective cell and organ function.
- Gene therapies have the potential to reverse the physiological effects, rather than just symptoms, of a disease.
- Most small-molecule drugs that treat symptoms of chronic diseases also need to be administered frequently (e.g. daily, twice-daily), whereas successful gene therapies confer a range of benefits after a single dose.
- Gene therapy is not subject to compliance problems, drug-drug interaction, pharmacokinetic and pharmacodynamic challenges that exist throughout the treatment course of conventional therapy.
COMPONENTS OF A SUCCESSFUL GENE THERAPY
Several factors play a critical role in gene therapy – if any of these components are not correct, a gene therapy will not be successful:
- Gene: The right gene that is central to the disease-reversing process and effective when inserted in the cell(s)
- Vector: The delivery method used to transport the gene to its target cell(s)
- Cell target: The right cells to receive the gene
- Transfection %: The level of uptake of the gene in the target cell(s) due to the right vector and route of administration