SEATTLE – A novel extrasynaptic gamma-aminobutyric acid (GABA)–receptor agonist called OV-101 was safe and well-tolerated in adult and adolescent Angelman syndrome patients in a 12-week phase 2 trial. In a secondary analysis, the treatment appeared to improve sleep.
Angelman syndrome is associated with a microdeletion on chromosome 15 encompassing the ubiquitin protein ligase E3a (UBE3A) gene. The resulting loss of expression of the UBE3A protein leads to increases in the uptake of GABA and reduces levels of extrasynaptic GABA. Patients with Angelman syndrome typically have motor dysfunction, often extreme: “These kids are very excitable, very active, and they have lots of trouble with sleep,” said Alex Kolevzon, MD, professor of psychiatry and pediatrics at the Icahn School of Medicine at Mount Sinai, in an interview.
Dr. Kolevzon presented the results at a poster session at the annual meeting of the American Academy of Child and Adolescent Psychiatry.
Thewas conducted at 12 sites in the United States and 1 in Israel. Ovid Pharmaceuticals plans to apply to the Food and Drug Administration later this year for approval. There is no existing drug for Angelman syndrome, and the study provided good safety reassurance. “There were some side effects, but for the most part we considered them mild, and only four (out of 88 subjects) discontinued because of side effects,” said Dr. Kolevzon.
The researchers used actigraphy to gain a more objective measure of sleep in the study participants. They randomized 88 patients with Angelman syndrome (aged 13-49 years) to receive placebo in the morning and 15 mg of OV-101 at night, 10 mg OVID-101 in the morning and 15 mg OVID-101 at night, or placebo both in the morning and at night.
Pyrexia occurred in 24% of the group who received the active drug only at night, 3% of the group given the twice-daily dose, and 7% of the placebo group. Seizures occurred in 7% of the once-daily group and 10% of the twice-daily group; seizures were not noted in the placebo group.
The main efficacy outcome measure was the Clinical Global Impressions-9 (CGI-9) scale. The once-daily group had a significant benefit in the sleep domain at 12 weeks, compared with placebo (difference, –0.77; P = .0141), but the twice-daily group had only a trend toward improvement in sleep (difference, –0.45; P = .1407).
Both active therapy groups had significant improvement in CGI-9 measures after 12 weeks of treatment compared to placebo – the twice-daily group (P = .0206, Fisher’s Exact Test) and the once-daily group (P = .0006, mixed model repeated measures analysis).
The actigraphy analysis, conducted in the 45% of patients who could tolerate its use, found that, compared to placebo, the once-daily dosing group experienced an 25.7 minute improvement in latency to sleep onset (P = .0147), as well an approximately 50 minute reduction in sleep time during the day, and a 3.65% improvement in sleep efficiency.
OV-101 has the potential to treat other conditions as well. “Obviously there are a lot of neurodevelopmental disorders where you see dysregulation between the GABAergic and glutamergic systems. This is a drug that has a unique effect on the GABAergic system. It’s already being studied in Fragile X syndrome, where we see this same kind of dysregulation and excess excitation,” said Dr. Kolevzon.
Dr. Kolevzon is a consultant for several drug companies including Ovid Therapeutics.
SOURCE: AACAP 2018. .