1. A randomized, double-blind, placebo-controlled phase II trial to explore the effects of a GABA A -α5 NAM (basmisanil) on intellectual disability associated with Down syndrome.
- Author
-
Goeldner C, Kishnani PS, Skotko BG, Casero JL, Hipp JF, Derks M, Hernandez MC, Khwaja O, Lennon-Chrimes S, Noeldeke J, Pellicer S, Squassante L, Visootsak J, Wandel C, Fontoura P, and d'Ardhuy XL
- Subjects
- Adolescent, Child, Child, Preschool, Humans, Morpholines, Oxazoles, Pyridines, Quality of Life, Treatment Outcome, Young Adult, gamma-Aminobutyric Acid therapeutic use, Down Syndrome complications, Down Syndrome drug therapy, Intellectual Disability complications, Intellectual Disability drug therapy
- Abstract
Background: There are currently no pharmacological therapies to address the intellectual disability associated with Down syndrome. Excitatory/inhibitory imbalance has been hypothesized to contribute to impairments in cognitive functioning in Down syndrome. Negative modulation of the GABA
A -α5 receptor is proposed as a mechanism to attenuate GABAergic function and restore the excitatory/inhibitory balance., Methods: Basmisanil, a selective GABAA -α5 negative allosteric modulator, was evaluated at 120 mg or 240 mg BID (80 or 160 mg for 12-13 years) in a 6-month, randomized, double-blind, placebo-controlled phase II trial (Clematis) for efficacy and safety in adolescents and young adults with Down syndrome. The primary endpoint was based on a composite analysis of working memory (Repeatable Battery for the Assessment of Neuropsychological Scale [RBANS]) and independent functioning and adaptive behavior (Vineland Adaptive Behavior Scales [VABS-II] or the Clinical Global Impression-Improvement [CGI-I]). Secondary measures included the Behavior Rating Inventory of Executive Functioning-Preschool (BRIEF-P), Clinical Evaluation of Language Fundamentals (CELF-4), and Pediatric Quality of Life Inventory (Peds-QL). EEG was conducted for safety monitoring and quantitatively analyzed in adolescents., Results: Basmisanil was safe and well-tolerated; the frequency and nature of adverse events were similar in basmisanil and placebo arms. EEG revealed treatment-related changes in spectral power (increase in low ~ 4-Hz and decrease in high ~ 20-Hz frequencies) providing evidence of functional target engagement. All treatment arms had a similar proportion of participants showing above-threshold improvement on the primary composite endpoint, evaluating concomitant responses in cognition and independent functioning (29% in placebo, 20% in low dose, and 25% in high dose). Further analysis of the individual measures contributing to the primary endpoint revealed no difference between placebo and basmisanil-treated groups in either adolescents or adults. There were also no differences across the secondary endpoints assessing changes in executive function, language, or quality of life., Conclusions: Basmisanil did not meet the primary efficacy objective of concomitant improvement on cognition and adaptive functioning after 6 months of treatment, despite evidence for target engagement. This study provides key learnings for future clinical trials in Down syndrome., Trial Registration: The study was registered on December 31, 2013, at clinicaltrials.gov as NCT02024789., (© 2022. The Author(s).)- Published
- 2022
- Full Text
- View/download PDF