More than two-thirds of patients who received prednisolone after showing no response to vigabatrin demonstrated complete electroclinical response at 2 weeks, with most sustaining response at 6 weeks.
Data from a retrospective study presented at the American Epilepsy Society (AES) Annual Meeting, December 3-7, 2021, showed improved complete electroclinical responses (ECR) with treatment of high-dose, 8-mg/kg/day prednisolone (Rayos; Horizon Pharma) in children with infantile spasms who did not respond to vigabatrin (Sabril; Lundbeck).1
The retrospective study, presented by Wafaa Al Shehhi, MD, clinical fellow, The Hospital for Sick Children, in Ontario, Canada, included 65 children with hypsarrhythmia, hypsarrhythmia variant, or multiple independent spike foci on electroencephalography (EEG) with infantile spasms. Individuals were treated with vigabatrin as first line antiseizure medication (ASM) followed by high-dose oral prednisolone in cases that did not respond.
Demographically, the cohort was a mean age of 6.3 months (standard deviation [SD], 4.2]) at onset of spasms, with a median estimated delay from onset to treatment of 11 days (interquartile range [IQR], 5-30]). More than not, patients had a genetic etiology (n = 25; 38.5%) and the highest proportion of patients presented with a normal developmental status at the time of onset of spasms (n = 22; 33.8%).
At 2 weeks, complete ECR was reported by 30.8% (20 of 65) of the patients after vigabatrin use. Of the remaining 45 children who did not respond to vigabatrin, more than three-quarters (77.8%) achieved complete ECR 2 weeks after prednisolone initiation. These responses were sustained by 66.7% (30 of 45) of the prednisolone-treated population at the 6-week mark. Notably, prednisolone was generally well-tolerated.
The investigators originally hypothesized that high-dose prednisolone may result in similar rates of ECR in comparison to previously published data on adrenocorticotropic hormone (ACTH) therapy; however, at the end of the study, the concluded that prednisolone may be a reasonable and more feasible alternative to ACTH for the treatment of infantile spasms.
"Further trials exploring the comparative effectiveness of 8 mg/kg/day prednisolone with ATCH, dose-response relationship with prednisolone, and exploring various drug combination therapies to improve efficacy are warranted," the study authors concluded.
Vigabatrin was first approved by the FDA in 2009 and later had its indication expanded in 2020 to include the treatment of focal epilepsy at different ages. While other countries have used it for decades, it is only approved in the US to treat refractory focal epilepsy in children 2 years of age or older, infantile spasms in children 1 month to 2 years old, and children with infantile spasms.2
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