FAQs: Retinal Gene Therapy

WHAT IS GENE REPLACEMENT THERAPY?

Gene Replacement Therapy is a cutting-edge medical treatment that involves replacing a defective gene within a patient's cells with a healthy copy to correct genetic disorders. First conceptualized in the 1970s, it gained momentum with the successful treatment of several severe conditions in the 2000s. The therapy works by using vectors, typically modified viruses, to deliver the healthy gene to the patient's cells, allowing the cells to produce the correct proteins needed for normal function.

GENE REPLACEMENT & THE RETINA

One notable success is the treatment of Leber's congenital amaurosis (LCA), a rare inherited eye disorder, where gene therapy restored vision in patients who were previously blind due to a mutation in the gene RPE65.

The retina is considered a highly suitable location for gene therapy delivery because it is easy to access via basic surgery or injection, and the blood-brain barrier minimizes immune responses that can be caused by injecting a virus (vector) into the body.

HOW LONG DOES A CUSTOM GENE THERAPY TAKE TO MAKE? HOW MUCH DOES IT COST?

Based on previous examples of custom gene replacement therapies developed by other foundations, we expect it to take ~4 years to reach our first patient. Our goal is to deliver a dose of the therapy in 2028.

The total cost of the project is roughly $2.5-3M dollars; however, this cost can be significantly reduced as key foundational technologies currently under development become more available. Further, while the Ringel Family and Kizuna Foundation expect to fundraise a significant portion of this funding, there are numerous grants that will help fund key parts of the development plan such as manufacturing when we reach this stage. The key is to get started to have a program “in the game”

HOW LIKELY IS IT TO WORK?

Ultimately, we cannot be certain if this approach will bring therapeutic benefit to Stevie, Natalie, or other KIZ patients. Based on the size and function of the KIZ gene, we have a high degree of confidence that we can successfully deliver a healthy copy of the gene to the right retinal cells. How this translates to vision preservation is unknown, and this is a key reason we need support - only rigorous testing can make us confident this treatment is worth injecting into the retina.