Improvements maintained at 4 years after Luxturna administration
SAN DIEGO — Improvements in ambulatory navigation, light sensitivity and visual field continue to be maintained at 4 years of a phase 3 trial of Luxturna in patients with biallelic RPE65 mutation-associated retinal dystrophy, Arlene V. Drack, MD, said at the American Association for Pediatric Ophthalmology and Strabismus annual meeting.
In the trial, for which Drack is a clinical investigator, patients were enrolled 2:1 in the treatment arm with voretigene neparvovec-rzyl (Spark Therapeutics) and to a control arm in which the same treatment was delayed for 1 year.
None of the patients in either the control group or the treatment group could navigate an obstacle course well initially, but at the end of the first year, there was a “huge” difference between the treated group and the control group, Drack said. In the treatment group, navigation improved after 30 days and improvements have been maintained for 4 years.
Results for the control group were similar once those patients were treated. At 30 days after treatment, mobility test scores improved and remain improved at 3 years, she said.
“There were five subjects who had marked improvement at 1 year who then did change 1 standard deviation at years 2 to 4,” she said. “For three of those subjects, their mobility test score worsened between years 2 and 4, but none of them decreased below their pretreatment level, and two subjects actually increased to a better light level between years 2 and 4 than they had in the first year.”
Full-field light sensitivity threshold (FST) measures also improved after treatment in both groups, and that improvement was maintained over 4 and 3 years. FST is a measure of how dim a light can be seen when the person is completely dark adapted, Drack said.
“Visual field also improved in a similar fashion, but there was much more variability,” Drack said.
Visual acuity did not improve, either before vs. after treatment for individuals or between the treatment vs. control group in the first year.
“However, there was a lot of variability, and for some patients there was a clinically meaningful improvement in visual acuity,” Drack said.
No adverse events were associated with deleterious immune response. Ocular serious adverse events included loss of foveal function related to the administration procedure and retinal detachment at 4 years after treatment. – by Patricia Nale, ELS
Drack AV. How long does gene therapy last? 4 year follow-up of phase 3 voretigene neparvovec trial in RPE65-associated LCA/inherited retinal disease. Presented at: American Association for Pediatric Ophthalmology and Strabismus annual meeting; March 28 to 31, 2019; San Diego.
Disclosure: Drack reports no relevant financial disclosures.