Spark Therapeutics, a spinout of Children’s Hospital of Philadelphia, will team up with Genable Technologies to develop Genable’s lead therapeutic GT038, a gene therapy designed to treat rhodopsin-linked autosomal dominant retinitis pigmentosa (RHO adRP).
The value of the collaboration was not disclosed, though the companies did say Spark will receive milestone payments and royalties on future sales of GT038, as well as near-term revenue from the manufacture and supply of product.
Under their collaboration agreement, Genable will license adeno-associated virus (AAV) vector manufacturing patents from Spark, which in return will serve as exclusive manufacturer of GT038 and provide development advice and expertise to Genable to help in ongoing development of the gene therapy.
GT038 uses AAV vectors with an established safety and efficacy profile to deliver RNA interference (RNAi) molecules to suppress the expression of faulty and normal copies of RHO and restore normal gene expression. GT038 has been granted orphan drug designation in both the U.S. and Europe.
"The collaboration with Spark provides an exciting opportunity to greatly expedite development of Genable's novel therapy targeted toward RHO-adRP," Professor Jane Farrar, founder and director of Genable Technologies and a professor at Trinity College (Dublin), said in a statement.
RHO adRP is a debilitating form of inherited blindness resulting from any one of approximately 150 different mutations in the RHO gene. While developing individual therapies for so many mutations is practically impossible, Genable says its “suppression and replacement” therapeutic approach allows a single therapy to treat all of the mutations in a gene while still correcting the primary genetic defect. The suppression component eliminates the target mRNA independent of the particular mutation present in the affected individual, while the replacement component supplies an mRNA encoding the wild type or normal protein.
According to Genable, RHO adRP affects approximately 1 in 30,000 people and represents an already identified and potentially treatable population of around 30,000 patients in the U.S. and Europe. Genable estimates the market opportunity for GT038 in the RHO adRP subtype to be over $500 million.
Genable says its plans to develop other gene therapies for a number of other adRP subtypes.
With $50 million committed by CHOP, Spark has set out to develop, then deliver multiple one-time gene therapy products for debilitating diseases, through a founding team that grew from CHOP’s Center for Cellular and Molecular Therapeutics (CCMT) from its 2004 inception into a recognized center of gene therapy innovation in research, translation, and manufacturing.
Spark's lead drug candidate is a gene therapy for RPE65-related blindness that is now in Phase III clinical trials. The company says the RPE65 therapy has the potential to be the first approved gene therapy in the U.S., and the first treatment to address the significant unmet needs of patients living with blindness due to inherited retinal dystrophies. Spark also has a Phase I/II program in hemophilia B, and preclinical programs to address neurodegenerative diseases and other inherited retinal dystrophies and hematologic disorders.