Objectives: To examine the long-term safety and tolerability of orally-administered STX209 in patients with FXS. A secondary objective was to examine the open-label effects of STX209 on adaptive function in patients with FXS.
Methods: Subjects who completed the randomized, controlled study, and who met other inclusion/exclusion criteria, were invited to enroll in a 12-month, open-label extension study of STX209. The dose of STX209 was titrated upwards flexibly over the first 4 weeks. Clinicians could continue to adjust drug dosage throughout the remainder of the study, according to their best judgment. Up to 3 concomitant psychoactive medications were permitted. Follow-up visits were conducted at Weeks 4, 10, 20, 30, 40 and 52, with safety assessments and the ABC scale. The VABS and the Stanford-Binet IQ test were administered during the placebo-controlled trial, and then at Week 52 of the extension study.
Results: 45 subjects (6 female, 39 male; age range 6 – 31 years) enrolled in this open-label study, out of 46 who met eligibility criteria. 34 subjects (76%) remained in the study at Week 52. There were no serious adverse events. Data from the study are currently being compiled and analyzed. Available data from 15 subjects showed a change in the standard score on the VABS-Communication domain from 56.9 ± 13.2 (mean ± standard deviation) to 62.3 ± 12.4 at Week 52. The VABS-Composite score showed a smaller change, from 59.4 ± 9.2 to 61.7 ± 10.0. By contrast, Fisch et al. (1996) reported that VABS composite scores decreased in 22 out of 24 children and adolescents with FXS who were followed over a 2 year period.
Conclusions: Full data on subject disposition, safety, tolerability, and efficacy will be presented.
See more of: Treatments: A: Social Skills; School, Teachers
See more of: Prevalence, Risk factors & Intervention