CHICAGO—QLT, a biotechnology company, is focused on developing its synthetic retinoid program for the treatment of certain inherited retinal diseases, said David Saperstein, MD, chief medical advisor, speaking here during the Ophthalmology Innovation Summit. In the human eye, mutations in the RPE65 or LRAT gene can lead to vision loss.
Oral zuretinal acetate “replaces 11-cis-retinal and can restore vision in those with mutated RPE65 or LRAT genes,” Dr. Saperstein said. A Phase Ib study of IRD01 in children diagnosed shortly after birth or during childhood with Leber’s congenital amaurosis (LCA) or early-onset retinitis pigmentosa (RP) due to RPE65 or LRAT mutations found of those with an LRAT mutation, 10 of 14 (71%) were visual field responders and 6 of 14 (43%) had improved visual acuity (VA). In those RP subjects, 8 of 18 (44%) were visual field responders and 12 of 18 (67%) had improved VA. Combined, more than 80% of the subjects responded favorably after treatment, noted Dr. Saperstein.
The company’s open-label re-treatment study included 13 subjects with LCA and 14 with RP. In both arms, 70% responded positively, and positive outcomes included being able to walk with out use of a cane, reading writing on a blackboard, playing video games, and navigating in public places. Safety outcomes were consistent with the overall retinoid class.
QLT plans to start a Phase III placebo controlled, double-masked, multicenter (US, Canada, Brazil, Europe) study by the end of 2016.
“With an oral product, we can eliminate the need for surgery in these young patients, the oral formulation delivers bilateral treatment, and zuretinal acetate may merit study with other gene therapy approaches,” Dr Saperstein said.
David A. Saperstein, MD
David A. Saperstein, MD is a practicing vitreoretinal surgeon with 20 years’ experience in clinical medicine and drug development. He has been an investigator in over 20 clinical trials in this field.