A blind patient regained sight for over a year after receiving a single injection of an experimental gene therapy directly into the eyeball.
The treatment uses RNA molecules that can infiltrate cells and reverse a specific mutation linked tocongenital amaurosis of Leber, an eye disease that causes blindness early in life, according to research published yesterday in the journal Nature Medicine.
Interestingly, researchers at the University of Pennsylvania School of Medicine behind the treatment administered into the eyeball discovered its long-term effects largely by chance.
How the administered treatment works
The mutation underlying Leber's congenital amaurosis prevents cells from producing the protein CEP290, essential for the photoreceptor cells of the eye. The treatment administered directly into the eyeball introduced RNA into those cells, triggering the production of CEP290, and essentially reversing the mutation for many months.
The first test, according to a press release, was carried out in 2019. In that case, gene therapy was administered, again through injections into the eyeball, every three months. One of the participants, worried about possible side effects, withdrew from the study after the first injection.
In hindsight it was a huge stroke of luck.
One injection into the eyeball returns vision for a year
The new study focused only on that patient. Because? Simple. Because the restoration of vision lasted, in that case, for over 15 months from the injection into the eyeball. A long-term trend that would have been impossible to discover with other patients, given the periodic and much closer repetition of treatments.
These longer lasting benefits not only reduce the medical costs associated with one type of therapy, but also offer new impetus to scientists already working on other diseases to experiment much more with different formulations, intermediate dosages, delivery mechanisms.