Health-related quality of life in pediatric patients with partial onset seizures or primary generalized tonic-clonic seizures receiving adjunctive perampanel

Abstract

RATIONALE\nStudy 311 (E2007-G000-311; NCT02849626) was a Phase 3, multicenter, open-label single-arm study of adjunctive perampanel oral suspension in pediatric patients (aged 4 to <12\u202fyears) with partial-onset seizures (POS) (with/without secondarily generalized tonic-clonic seizures [SGTCS]) or primary generalized tonic-clonic seizures (PGTCS). Health-related quality of life (HRQoL) was an exploratory endpoint initially analyzed through simple descriptive summaries. The aim of this post hoc analysis was to provide a more thorough assessment of HRQoL.\n\n\nMETHODS\nThis analysis focused on EQ-5D-Y data collected at Baseline, Week 23, and Week 52. Individual dimensions, visual analog scale (VAS) and summed misery index (MI) were evaluated at all visits and compared by seizure type (POS versus SGTCS versus PGTCS), age (4 to <7 versus 7 to <12), and use of concomitant enzyme-inducing antiepileptic drugs (EIAEDs) (yes versus no). Paretian Classification of Health Change (PCHC) analysis summarized the proportion of patients who showed improvement or deterioration in HRQoL. Waterfall plots assessed changes in EQ-5D-Y scores by treatment-emergent adverse events (TEAEs) and by reduction in seizure frequency. Health state utility values associated with differing seizure frequency states were estimated using a linear mixed model.\n\n\nRESULTS\nOne hundred and fifteen patients completed EQ-5D-Y at relevant study visits (Seizure type: POS n\u202f=\u202f84 [of which 21 had SGTCS], PGTCS n\u202f=\u202f31; Age: 4 to <7\u202fyears n\u202f=\u202f30, 7 to <12\u202fyears n\u202f=\u202f85; Concomitant EIAEDs: Yes n\u202f=\u202f35, No n\u202f=\u202f80). Completion rates out of those expected to complete EQ-5D-Y were high at both timepoints (84.4% at Week 23 and 97.2% at Week 52). Overall, VAS/MI remained stable over time (did not exceed minimal important difference); this was similar according to seizure type, age, and EIAED usage. In patients with no problems on any EQ-5D-Y dimension at Baseline, nearly all retained their full health at Week 23 (94.7%), and all retained it at Week 52 (100.0%). PCHC analysis showed fewer patients with POS experienced deterioration in EQ-5D-Y than patients with PGTCS at Week 23 (24.1% versus 42.1%). Not experiencing a TEAE, or remaining seizure-free, was associated with improvements in VAS score at Week 23 compared to those experiencing TEAEs or seizures, respectively. Health state utility values (HSUVs) were estimated as follows: seizure free (LS Mean 0.914 [95% CIs 0.587, 1.240]), ≥1 seizure per year (0.620 [0.506, 0.734]), ≥1 seizure per month (0.596 [0.338, 0.855]), ≥1 seizure per week (0.284 [-0.014, 0.582]).\n\n\nCONCLUSIONS\nAn in-depth analysis of EQ-5D-Y data allowed for a more nuanced exploration of HRQoL than previous descriptive summaries. Our findings provide evidence that perampanel as adjunctive therapy did not result in deterioration of patient HRQoL. The association between TEAEs or remaining seizure-free and HRQoL warrants further exploration. Increasing seizure frequency was associated with decreasing HSUVs; these can inform cost-effectiveness modeling of perampanel and other therapies aiming to reduce seizure frequency in pediatric patients.