Consistent Treatment Effect Seen With Brivaracetam Across Patients With Intellectual Disability

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Brivaracetam was largely well tolerated and shown to be effective for a proportion of patients with intellectual disability, indicated by similar responses across different levels of intellectual disability severity.

Rohit Shankar, MBBS, FRCPsych

(Credit: University of Plymouth)

In a recently published study, brivaracetam (Briviact; UCB), an FDA-approved antiseizure medication (ASM), demonstrated similar efficacy, tolerability, and physical and mental health adverse effects among patients with epilepsy regardless of whether they had intellectual disability (ID). These data, along with previously published real-world studies, indicate that brivaracetam may be an appropriate ASM for patients with ID.¹

Pooled data from 12 UK NHS Trusts from 2016–2022 were analyzed, comprising 102 patients with epilepsy without ID and 37 with ID. Of those with ID, 17 were mild and 20 were moderate to profound. Those with ID were more likely to be younger (P <.001), male (P <.005), and to have existing neurodevelopment conditions (P <.001). Between the 2 groups, those with no ID had slightly higher mean starting doses of brivaracetam (57 mg vs 49 mg) for the 12-month study.

Led by Rohit Shankar, MBBS, FRCPsych, a professor of neuropsychiatry at the University of Plymouth, this was the first study on brivaracetam comparing ID cohorts with differing severity and non-ID patients. Across all groups, the efficacy of brivaracetam, measured using seizure reductions of at least 50%, was 30.2% at 12 months. Overall, the efficacy rate for patients with ID (32.4%) was comparable with the rate for the non-ID group (29.4%), with no significant difference (P = .260). Across the whole cohort of participants, those aged 40-50 and older than 50 reported significantly better efficacy outcomes than those less than 30 (P = .02 and P = .05, respectively) after accounting for ID severity.

In total, 25.5% of patients withdrew brivaracetam during the 12-month study, with slightly higher, but nonsignificant rates in both ID severity groups (mild ID: 76.5%; moderate-profound: 80.0%; P = .660). When retention at 12 months for all patients with ID (78.4%) was compared with the no ID group (73.0%), this difference was also not significant (P = .373).

Within the 12 months since initiating treatment, 16.5% and 20.1% of participants, respectively, reported physical and mental/behavioral adverse events (AEs). Overall, a univariable analysis revealed no differences in physical AEs regardless of age, gender, and ID group (P = .869). Mental and behavioral AEs were more prevalent across the combined ID group when compared with those without ID (ID: 27.0%; no ID: 17.6%) but again this was not statistically significant (P = .441).

There were some limitations to the study, including the fact that more than half of NHS patients approached to participate did not, therefore the data may not be representative of all patients prescribed brivaracetam at study sites. In addition, recruitment was completed between 2020-2022 which meant that many patients with ID were approached through postal invite rather than face-to-face in clinics which occurred in other Ep-ID arms. Furthermore, investigators warned readers of caution when interpreting these data, as the study had low numbers and a higher risk of underpower.

The first multisite study of brivaracetam, published in 2018, was conducted in Spain and featured 570 patients, 182 of whom had ID. After 12 months of treatment, retention rates were 70.4%, but brivaracetam was less effective among those with ID, demonstrated by 50% reductions in reported seizure activity (ID: 32.3%; no ID: 43.4%; P = .011). Notably, AEs were also less prevalent in those with ID (32.4%) vs those without (43.3%; P = .013). Overall, the study authors concluded that the drug is safe and effective, with no unexpected AEs that occurred over 1 year.

REFERENCES
1. Allard J, Henley W, Sellers A, et al. Efficacy and tolerability of brivaracetam in people with intellectual disability compared to those without intellectual disability. Epilepsy and Behav. 2024;158:109906. doi:10.1016/j.yebeh.2024.109906
2. Villaneuva V, Lopez-Gonzalez FJ, Mauri JA, et al. BRIVA-LIFE-A multicenter retrospective study of the long-term sue of brivaracetam in clinical practice. Acta Neurol Scand. 2019;139(4):360-368. doi:10.1111/ane.13059