NEW YORK – The latest safety and efficacy data from a Phase I/II trial of Atsena Therapeutics' investigational gene therapy for an inherited eye condition has given researchers more confidence to move the program into late-stage development.
On Thursday, Durham, North Carolina-based Atsena announced that the 12-month safety and efficacy data from a Phase I/II trial of ATSN-101 in patients with Leber congenital amaurosis (LCA) due to biallelic GUCY2D mutations were published in the Lancet.
LCA is an inherited disease of the retina that impairs vision and lacks approved treatments. LCA due to mutations in the GUCY2D gene (LCA1) is one of the most common forms of the disease, accounting for 20 percent of cases, and can manifest more severely, causing blindness in infants. Atsena's ATSN-101 is a subretinal adeno-associated virus 5-based gene therapy that delivers a functional GUCY2D gene to photoreceptors.
In the recently published study, 13 patients received ATSN-101 at various doses. Patients who received the highest dose experienced a one-hundredfold improvement in vision in the treated eye compared to baseline as measured by the full-field stimulus test, and these improvements persisted for a year. Researchers also saw modest vision improvements among patients on the high dose of the gene therapy as measured by the best correct visual acuity test. The treatment was well tolerated at the highest dose.
After seeing promising six-month data last year from this Phase I/II trial, Atsena had indicated it was considering moving ATSN-101 into pivotal trials. Now, this 12-month data provides even further support for advancing the gene therapy into Phase III trials.
"The improvements in visual function and tolerability we saw at the high dose of ATSN-101 at 12 months posttreatment in the ongoing Phase I/II trial support a future randomized, controlled Phase III trial to further evaluate this subretinal gene therapy in patients with LCA1," Artur Cideciyan, a research professor of ophthalmology at the University of Pennsylvania's Scheie Eye Institute and senior author of the paper, said in a statement. "ATSN-101 represents a significant advancement in the reversal of blindness that begins in childhood."