NEW YORK – SparingVision on Wednesday said that based on the positive recommendation from a data safety monitoring board, it has begun testing its retinitis pigmentosa gene therapy candidate SPVN06 at the third and final dose within the dose-escalation portion of a Phase I/II trial.
So far, six patients participating in the PRODYGY trial have received SPVN06 at one of two lower doses. Investigators found the gene therapy had a favorable safety and tolerability profile at these lower doses.
SPVN06 aims to prevent or slow the characteristic degeneration of cone photoreceptors that occurs in patients with retinitis pigmentosa, a group of rare inherited eye diseases that can lead to blindness. Instead of replacing the genes that when mutated, cause the eye disorder, SPVN06 uses an adeno-associated virus vector to deliver a working copy of the DNA that encodes proteins that can keep cone photoreceptors from degrading. Specifically, the gene therapy is designed to restore neurotrophic factor RdCVF, which is produced by functioning rods in the retina, and promote RdCVFL, an antioxidant that protects cones against oxidative stress. In this way, SparingVision believes SPVN06 can be given to patients regardless of the retinitis pigmentosa-causing genetic mutation they have inherited.
After completing the Phase I dose-escalation portion, Paris-based SparingVision expects to advance SPVN06 into a three-armed, randomized-controlled Phase II trial in Q2. In this part of the Phase I/II study, investigators will test the activity of two gene therapy doses and compare these patients' outcomes against those who are not treated.
The firm is also planning to test SPVN06 in other retinal diseases that could be treated by cone preservation and said it may begin investigational new drug-enabling studies for the gene therapy as a treatment for geographic atrophy this year.