- GlaxoSmithKline on Tuesday became the first pharma giant to file for marketing authorization of a gene therapy, Reuters reports. But the move comes on the heels of disappointing news for a different gene therapy, wherein University of Pennsylvania researchers found that previously blind patients who regained vision due to such techniques started to lose vision again three years later.
- Glaxo's gene therapy product is for the treatment of a subset of children with ADA Severe Combined Immune Deficiency who cannot find suitable marrow donors. In the U Penn case, the gene therapy, which was delivered virally to the eyes, instructed the eyes to begin producing healthy copies of the RPE65 gene.
- Although patients in the U Penn study experienced improved vision as a result of the gene therapy, their vision peaked and then started to diminish as the underlying pathology of their disease—Leber congenital amaurosis (LCA)—continued to progress.
Gene therapy has been a source of inspiration, as well as skepticism. In fact, this therapy, which is often associated with costs exceeding $1 million, has even been consigned to the dustbin by some companies, such as Biogen, and then suddenly picked up again. And Glaxo's decision to apply for this approval only raises the stakes.
In the U Penn case, patients with LCA were treated with gene therapy designed to spur production of a protein needed to regain vision. Although it worked for a period of time, over time, the effects wore off. Does that mean that it's not a viable therapy? Not at all, according to the U. Penn researchers, headed by Samuel Jacobsen. Jacobsen contends that follow-up therapy could potentially be used to maintain vision, as could some type of combination therapy.
Spark Therapeutics is independently developing therapy for LCA patients, using the same target, and will continue developing this therapy, which is currently in phase III.