Luxturna: A new gene therapy for Retinal Dystrophy
Luxturna (voretigene neparvovec-rzyl), is a new gene therapy approved for the treatment of a rare form of genetic retinal disorder that can lead to blindness through subretinal injection.
On December 19, 2017, the U.S. Food and Drug Administration approved Luxturna for the treatment of retinal dystrophies in pediatric and adult patients that are associated with mutation of biallelic RPE65.
RPE65 mutation-associated retinal dystrophy is a genetic retinal disorder associated with progressive visual impairment. The RPE65 gene aids in the production of an enzyme which is vital for normal visual functions.
RPE65 gene mutations reduce or may eliminate RPE65 gene activity disrupting the visual cycle.
RPE65 gene mutations cause several retinal dystrophies such as Leber’s congenital amaurosis and autosomal recessive retinitis pigmentosa which cause early-onset night blindness.
Patients with RPE65 mutation-associated retinal dystrophy suffer from vision loss that may eventually lead to complete blindness. The deterioration in vision starts at an early age and is progressive. Biallelic RPE65 mutation-associated retinal dystrophy affects about 1,000 to 2,000 patients in the United States.
Luxturna is administered to the patient by directly delivering a normal copy of RPE65 gene using a modified adeno-associated virus as a vehicle to viable retinal cells. It is administered via subretinal injection in a surgical procedure.
The recipient retinal cells then produce the enzymes to restore vision. The injected RPE65 gene copy does not replace nor eliminate the mutated genes; it simply coexists with the original genes.
Luxturna is the first directly administered gene therapy designed to treat a disease caused by mutations in a particular gene.
Precautions with Luxturna
Luxturna should only be administered to patients with viable retinal cells.
Luxturna should be injected subretinally by an experienced vitreoretinal surgeon Luxturna should be administered in each eye separately with at least 6 days interval.
Oral Prednisolone should be prescribed for a short period of time post injection to reduce the risk of possible immune and inflammatory reactions.
Most common Side Effects of Luxturna
Elevated intraocular pressure
The safety and efficacy of this new gene therapy has been established through clinical trials where 41 patients with confirmed biallelic RPE65 gene mutations underwent the program. In the program, vision was assessed by the subjects’ ability to navigate an obstacle course under different light conditions.
The patients treated with Luxturna demonstrated significant improvement in vision by being able to complete the course in low light setting after a year of treatment.
Spark Therapeutics Inc., a Philadelphia-based biotechnology company, priced Luxturna for $850,000 for a one-time treatment. It costs $425,000 per eye. But since the genetic disorder affects both eyes, most patients would require treatment for both eyes.
Spark Therapeutics promises a one-time treatment, and so far the company has been following up with patients enrolled in the study and claims no deterioration in vision for four years after receiving Luxturna.
This innovation in gene therapy can make life-changing results for those afflicted with a genetic condition that has a very little to no hope of treatment. It is also a remarkable progress in the field of gene therapy, and such breakthrough can potentially open doors for other researches.