On October 12, 2017, the U.S. Food and Drug Administration's (FDA) Cellular, Tissue and Gene Therapies Advisory Committee has paved the way for the agency's first approval of a gene therapy to treat a disease caused by a genetic mutation.
A panel of external experts from this committee unanimously voted that the benefits of the therapy, which treats a form of hereditary blindness, outweigh its risks. The FDA is not required to follow the guidance of its advisory committee(s), but it often does. A final decision on the fate of the drug being developed, called Voretigene Neparvovec (Luxturna), is expected by January 12, 201821.
Voretigene Neparvovec (Luxturna) is being developed by Spark Therapeutics, and is designed to treat an individual who has two mutated copies of a gene called RPE65. The mutation impairs the eye's ability to respond to light, and ultimately lead to the destruction of photoreceptors in the retina.
The treatment consists of a virus loaded with a normal copy of the RPE65 gene. The virus is injected into the eye, where the gene is expressed and supplies a normal copy of the RPE65 protein.
The advisory committee's recommendation is based on Luxturna's clinical development program, which includes the first completed randomized, controlled Phase 3 gene therapy clinical trial ever conducted for a genetic disease. In the original Phase 3 intervention group, participants aged four to 44 years on an average maintained the functional vision and visual function improvements were demonstrated 30 days after Luxturna administration through their last annual follow-up visit, as measured by bilateral Multi-luminance Mobility Test (MLMT) score change and full-field light sensitivity threshold (FST) testing. Data from a cohort of the Phase 1 clinical trial, in which investigational Luxturna was administered to the contralateral, or second previously uninjected eye, showed similarly maintained mean improvements. As part of the Biologics License Application (BLA) to FDA, Spark also submitted the results of two Phase 1 clinical trials, a natural history study and a MLMT validation study.
There are currently no pharmacological treatment options for people living with RPE65-mediated IRD, who in most cases progress to complete blindness.
Luxturna is under Priority Review with FDA, with an assigned Prescription Drug User Fee Act (PDUFA) dated January. 12, 2018. LUXTURNA has received orphan drug, breakthrough therapy and rare pediatric disease designations from FDA. In August 2017, Spark Therapeutics' Marketing Authorization Application (MAA) for LUXTURNA was validated by European Medicines Agency (EMA). LUXTURNA also has received orphan product designations from EMA.
Conclusion
If Luxturna gets approved by the US regulator, it will be the first gene therapy for an inherited condition. And will probably open the door for other gene-therapy treatments for genetic disorders.
Footnote
21 http://ir.sparktx.com/phoenix.zhtml?c=253900&p=irol-newsArticle&cat=news&id=2306441
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