Abstract
BACKGROUND
Levetiracetam and valproic acid are two of the most commonly prescribed antiepileptic drugs (AEDs) in patients with a glioma and epilepsy. This study aimed at estimating the cumulative incidence of treatment failure of first-line monotherapy levetiracetam versus valproic acid in glioma patients with epilepsy.
METHODS
In this retrospective observational study, a competing risk model was used to estimate the cumulative incidence of treatment failure, from AED treatment initiation, for the two AEDs with death as competing event. Patients were matched on baseline covariates potentially related to treatment assignment and/or outcomes of interest according to the nearest neighbour propensity score matching technique. Secondary outcomes were the cumulative incidence of recurrent seizure, from AED treatment initiation (estimated with a competing risk model), and severity of adverse effects. Maximum duration of follow-up was 36 months.
RESULTS
In total, 776 patients using levetiracetam and 659 using valproic were identified. Matching resulted in two equal groups of 429 patients, with similar covariate distribution. The cumulative incidence of treatment failure (any reason) at 12 months for levetiracetam and valproic acid was equal to 33% (95%CI=29-38%) versus 50% (95%CI=45-55%), respectively (p< 0.001). The cumulative incidence of treatment failure due to uncontrolled seizures was significantly lower for levetiracetam compared to valproic acid (12 months: 16% [95%CI=12-19%] versus 28% [95%CI=23-32%]; p< 0.001), but no differences were found for treatment failure due to adverse effects (12 months: 14% [95%CI=11-18%] versus 15% [95%CI=11-18%]; p=0.636). The cumulative incidence of recurrent seizure of levetiracetam was significantly lower compared to valproic acid (12 months: 54% [95%CI=49-59%] versus 67% [95%CI=62-71%]; p< 0.001). No significant differences were found for level of toxicity.
CONCLUSION
Our results suggest that levetiracetam has superior efficacy compared to valproic acid, while showing a similar level of toxicity. Therefore, levetiracetam seems the preferred choice for first-line AED treatment in glioma patients.