Vice President, Global Health Economics and Outcomes Sunovion Pharmaceuticals Inc. Marlborough, Massachusetts
Rationale: Eslicarbazepine acetate (ESL) is a third-generation antiepileptic drug (AED) approved for the treatment of patients with focal seizure (FS). ESL is often used later in the treatment cycle after prior first- and second-generation AEDs, such as levetiracetam (LEV), oxcarbazepine (OXC), and/or carbamazepine (CBZ). The objective of this study was to examine the association between initiating treatment with ESL on emergency room (ER)-initiated hospitalizations and inpatient (IP) and outpatient (OP) visits among patients with FS who switched from LEV, OXC, and/or CBZ. Methods: This was a retrospective cohort study using the IQVIA PharMetrics® Plus database from 2016 to 2018. The treatment group was defined as patients who received LEV, OXC, and/or CBZ in the baseline period and switched to ESL. The control group was defined as randomly selected patients who were prescribed OXC/LEV/CBZ and had six months of follow-up. Patients were evaluated for the study period from 12 months before the index date (baseline period) to six months after the index date (follow-up period). Patients in the control group were matched (1:1) using propensity scores to patients in the treatment group on baseline characteristics (e.g., age, gender, payer, comorbidities, number of prior AEDs). For the treatment group, index date was the date of switch from prior-generation AED to ESL (treatment group). For the control group, the date of prescription for OXC/CBZ/LEV six months prior to end date was defined as index date. Study outcomes included all-cause healthcare resource utilization (HCRU) for the following categories: ER-initiated hospitalizations, IP visits, and OP visits. HCRU were tabulated as the percentage of patients with > 1 visits of each type. Statistical differences between groups were compared using the chi-square test. Due to small expected values for some categories, statistical significance was also tested using Fisher’s exact tests. Results: A total of 154 patients were included in each of the treatment and control groups. Mean age in both groups was approximately 40 years, and most patients were commercially insured (treatment group: 97%; control group: 99%). Approximately half the patient population was female (treatment group: 53%; control group: 49%). IP visits were significantly lower in patients in the treatment group (3%) compared to the control group (8%, chi-square test, P = 0.046; Fisher’s exact test, P = 0.07). ER-initiated hospitalizations and OP visits across the two groups were similar: ER-initiated hospitalizations: treatment group 2% vs. control group 1%, P = 0.655; OP visits: treatment group 92% vs. control group 91%, P = 0.86. Conclusions: This real-world study suggests that ESL initiation following generic AEDs was associated with a significant reduction in IP visits compared to patients continuing treatment with LEV, OXC, and/or CBZ, but there were no significant differences in ER-initiated hospitalizations or OP visits. Funding: Please list any funding that was received in support of this abstract.: Sunovion Pharmaceuticals Inc.