Therapeutic AmicusExperimental AT-GTX-501 gene therapy stabilized motor and language function in children with late infantile variant neuronal ceroid lipofuscinosis 6 disease – also known as CLN6 Latte disease – two years after treatment, based on interim data from a phase 1/2 clinical trial.
The ongoing trial (NCT02725580) evaluates the safety and effectiveness of a single injection of the treatment into the spinal canal (intrathecal) in patients with CLN6 Batten, aged 1 year and over, able to walk with assistance.
AT-GTX-501 uses an inactivated adeno-associated virus (AAV) as a vehicle to deliver a working copy of the CLN6 gene, which is mutated in people with the disease, causing the toxic build-up of deposits called lipofuscins, especially in cells of the central nervous system (brain and spinal cord).
“We are delighted to share these positive interim clinical data for our intrathecal AAV gene therapy with the CLN6 community,†said Jeff Castelli, PhD, director of development at Amicus, in a statement. Press release. “These data continue to suggest that our gene therapy has the potential to be a treatment option for children living with Batten disease CLN6.”
The results were recently presented in the form of a virtual poster titled “Single-dose AAV9-CLN6 gene transfer stabilizes motor and language function in infantile neuronal ceroid-lipofuscinosis disease variant 6 (vLINCL6): interim results from the first clinical trial of gene therapy,” to 16th International Congress of Child Neurology and 49th Annual Meeting of the Society for Child Neurology.
After receiving AT-GTX-501, patients returned for clinical visits on days 7, 14, 21, and 30, and then every three months for up to 24 months.
Disease progression was followed by changes in scores on the Hamburg Motor & Language (HML) scale, a measure of mobility and speech difficulties, with a combined scale of zero to six. Lower scores reflect more severe disability.
Evaluation of 12 patients at 12 months showed the average rate of decline to be 0.4 points, compared with a drop of 1.2 points in 16 patients in a group derived from a previous natural history study CLN6 (NCT03285425).
After 24 months, data was available for eight patients, who showed an average rate of decline of 0.6 versus 2.4 points in the natural history group.
Of these eight patients, one (12.5%) had an increase in overall HML score greater than one, two patients (25%) had no change in score, four (50%) showed a decrease in one point and one (12.5%) fell more than two points.
In contrast, six of 16 participants in the natural history group had a decrease in HML by one point, and the remaining 10 (62.5%) had a decrease of more than two.
“I remain satisfied with the progress of this trial as well as our collection of natural history data to further inform the results of AAV-CLN6 gene therapy,” said Emily de los Reyes, MD, PhD, principal investigator of the essay and professor of clinical pediatrics and neurology at Ohio State University College of Medicine. “The interim results show that this experimental gene therapy has the potential to slow the progression of neurological disease in children with Batten disease CLN6. “
Interim safety data were available for 13 patients, which showed that AT-GTX-501 was generally well tolerated. Serious adverse events were reported in five patients, four of which were considered to be treatment-related, including vomiting, fever and upper abdominal pain. All four recovered, and there was no other pattern of adverse events related to the AAV vehicle or an anti-CLN6 immune response.
Participants who complete this study have the option of participating in a long-term follow-up study (NCT04273243) which opened in January and runs until 2035.
AT-GTX-501 has been tuned rare pediatric disease and orphan drug designations speak United States Food and Drug Administration; Iin the EU, he has FIRST and orphan drug designations. These designations provide incentives and resources to encourage the development of disease-focused therapies with few treatment options.
Amicus awaits comments on AT-GTX-501 from regulatory agencies in 2021.
