Gene therapy eyes medical breakthrough
This month, a gene therapy targeting a genetic disease was recommended for FDA approval in the United States. The treatment, developed by Spark Therapeutics and researchers at Children’s Hospital of Philadelphia, targets the retinal gene to restore eyesight by inserting a copy of a healthy gene directly into cells in the eye’s retina. James Dahlman’s work lies at the interface of nanotechnology, genomics, and gene editing
The potential FDA approval of this gene therapy is a huge step for our field. It gives hope to people who are born with Leber congenital amaurosis, a rare inherited genetic blindness. The data suggest that a viable treatment is available.
This news is also inspiring to me and my colleagues who develop genetic therapies. I’ve always been fascinated by genetics. To me, it’s the most interesting field in the world. Gene therapy is an experimental technique that uses DNA or RNA to treat diseases, including hemophilia, Parkinson’s, cancer, HIV and, now, genetic blindness. Since many diseases are caused by defunct genes, gene therapies may help manage a number of diseases, and could even help other drugs or surgery.
My lab focuses on a key problem in gene therapies: how to deliver them to the right cells in the body. We design small spheres that protect the genetic drug inside the body and deliver them to the right cells – these small spheres are called nanoparticles. It’s critical that the gene therapies only target the unhealthy cells and avoid damaging healthy ones. We are focused on ensuring the nanoparticles know what paths to take to reach the correct organ to start the healing process. In the case of Leber congenital amaurosis, those healthy genes need to get to the retina.
Delivering genes to the right place is a major challenge. The practical issue with genetic drugs is that they don’t work unless they get to the right cell in the body. You can have the world’s best genetic drug that's going to fix a tumor or eradicate plaque, but it’s not going to be effective unless it travels to the right organ. And the body has a lot of defenses to fight bacteria and viruses that keep our drugs from getting where they need to go.
All types of drug therapies have to be delivered. Our field has had the best success with the liver, with many clinical trials already successfully running using the same drug delivery systems. The liver is responding extremely well to these therapies, and we are healing livers and curing people. It’s extremely encouraging to see gene therapies for genetic blindness working as well. However, we have a lot of work to do. The brain, lung, pancreas, spleen, muscle, heart and other organs need good drug delivery as well.
