Neurodevelopmental Outcomes From the PREVeNT Trial

Tuberous Sclerosis Complex (TSC) is associated with high prevalence of epilepsy, intellectual and developmental disability, and autism spectrum disorder (ASD). PREVeNT, a Phase IIb, multicenter, double-blind placebo-controlled trial, evaluated the efficacy of vigabatrin in preventing intellectual and developmental disability and ASD in infants with TSC. Phenotypic, developmental, and ASD-specific outcomes at 36 months are presented.

Eighty-four infants with TSC were enrolled in PREVeNT across 13 TSC clinics in the United States. Participants underwent neurodevelopmental assessments at ages 6 months through 36 months. Clinical best estimate diagnosis of ASD or non-ASD along with a rating of clinical certainty was determined at 36 months.

Sixty-five participants completed assessments through 36 months of age. Mean cognitive scores on the Bayley-III were in the low average range at 12 months. Cognitive scores declined slightly in all groups over time. Adaptive scores were in the low average range for the seizure groups. For all neurocognitive measures, those in the watchful waiting group exhibited higher scores compared to the other cohorts. Language scores became more commensurate with cognitive scores by 36 months. The Clinical Certainty Rating was available for 58 patients, with 31% rated as having ASD; this did not differ by treatment assignment.

No significant differences in developmental or autism-specific outcomes were seen between treatment groups, and no participants without epilepsy were diagnosed with ASD. This may be due to early detection of seizures, closer developmental monitoring and follow-up in the trial, and impacts of the pandemic on study participation.