New evidence in adjunctive treatment of focal-onset seizures in adults: a critical appraisal

Seizure burden and healthcare resource utilization among people living with drug-resistant focal epilepsy in the United States

OBJECTIVE

This study investigated clinical characteristics, burden of uncontrolled seizures, and seizure-related healthcare resource utilization (HRU) among individuals living with drug-resistant focal epilepsy (FE) in the United States (US).

METHODS

Medical charts of adults with drug-resistant FE who initiated third-line (3 L) anti-seizure medication were extracted from clinical practices in the US (1/1/2013-1/31/2020). The index date, defined as the date of 3 L initiation, was used to indicate the emergence of drug resistance. Individuals on cenobamate were followed for any length of time from the index date. Demographic and clinical characteristics were analyzed descriptively. Primary clinical outcomes included seizure burden (i.e. change in seizure frequency and time to the first and second seizure events) and epilepsy-related HRU.

RESULTS

Overall, 189 neurologists/epileptologists contributed 345 charts of individuals living with drug-resistant FE (66% male; average age 24 years at diagnosis and 32 years at index date). 66% had ≥1 neurologic/neuropsychiatric comorbidity at baseline. Average monthly seizure rate decreased from 6.1 at baseline to 3.8 at follow-up; however, nearly half of individuals experienced worse/no change or only some improvement (<50% reduction) in seizure frequency. Most individuals (91%) had ≥1 epilepsy-related outpatient visit during follow-up. Unplanned HRU included emergency department visits (43%) and hospitalizations (24%), primarily due to breakthrough seizure events.

CONCLUSION

Despite the availability of many anti-seizure medications in the US, people living with drug-resistant FE continue to experience multiple seizures per month and incur substantial healthcare resources. Novel pharmacotherapies may help individuals living with drug-resistant epilepsy achieve seizure freedom.

Increasing challenges to trial recruitment and conduct over time

OBJECTIVE

This study was undertaken to evaluate how the challenges in the recruitment and retention of participants in clinical trials for focal onset epilepsy have changed over time.

METHODS

In this systematic analysis of randomized clinical trials of adjunct antiseizure medications for medication-resistant focal onset epilepsy, we evaluated how the numbers of participants, sites, and countries have changed since the first such trial in 1990. We also evaluated the proportion of participants who completed each trial phase and their reasons for early trial exit. We analyzed these trends using mixed effects generalized linear models accounting for the influence of the number of trial sites and trial-specific variability.

RESULTS

The number of participants per site has steadily decreased over decades, with recent trials recruiting fewer than five participants per site (reduction by .16 participants/site/year, p < .0001). Fewer participants also progressed from recruitment to randomization over time (odds ratio = .94/year, p = .014). Concurrently, there has been an increase in the placebo response over time (increase in median percent reduction of .4%/year, p = .02; odds ratio of increase in 50% responder rate of 1.03/year, p = .02), which was not directly associated with the number of sites per trial (p > .20).

SIGNIFICANCE

This historical analysis highlights the increasing challenges with participant recruitment and retention, as well as increasing placebo response. It serves as a call to action to change clinical trial design to address these challenges.