Epilepsy, Partial, Motor

Courtesy of Shutterstock Neurocrine Biosciences’ $50 million play for a rare type of childhood epilepsy doesn’t appear to be panning out as a Phase II study failed to meet its primary endpoint, the San Diego-based biopharma announced Tuesday. Acquired from Idorsia in May 2020, NBI-827104 is being studied in pediatric patients with epileptic encephalopathy with continuous spike-and-wave during sleep. This represents strike two against the drug. Neurocrine abandoned a program for essential tremors in July after the asset failed to show robust statistical significance or clinical relevance for that population. Affecting one out of 200 children with epilepsy, EE-CSWS is commonly characterized by focal motor seizures, most often during sleep, and a slow cognitive and behavioral function decline. Children with rare pediatric epilepsy are at higher risk of sudden unexpected death and are often left with severe impairment, even if seizures improve or stop. The STEAMBOAT study compared the efficacy of the T-type calcium channel blocker against a placebo for kids with EE-CSWS over a 13-week treatment period, which included two overnight stays for EEG monitoring. Without sharing specific data, Neurocrine stated the asset “did not meet the primary endpoint”, which was a reduction from baseline as compared to placebo in the ratio of spike-wave index after six weeks of treatment. The company was vague about a path forward for the drug, with Chief Medical Officer Eiry Roberts, M.D., saying only that Neurocrine would “continue to analyze the rich data set generated from this study to determine next steps.” A page on ClinicalTrials.gov updated on August 30 shows an extension study to evaluate the drug is “enrolling by invitation.” The announcement caused a small 5% dip in Neurocrine stock. Neurocrine continues to tout a healthy balance sheet thanks to its four commercially approved drugs. The company’s blockbuster drug Ingrezza is expected to pull in over $1.4 billion in 2022. Currently approved for tardive dyskinesia, a supplemental New Drug Application has been submitted to the FDA for chorea associated with Huntington’s disease. The company has an additional asset in the pipeline for another type of rare pediatric epilepsy – SCN8A-DEE. A Phase II study has already begun with eight patients enrolled to test safety and tolerability before reopening enrollment in Spring/Summer 2023.