Stiripentol fails to lower plasma oxalate in a dialysis-dependent PH1 patient

Primary hyperoxaluria type 1 (PH1) is a multisystemic metabolic disorder caused by an excessive production of oxalate by the liver. The majority of patients presenting in early infancy have end-stage renal disease (ESRD). While awaiting the results of sRNAi trials, the current standard treatment is combined liver-kidney transplantation. Recently, Stiripentol has been reported as a promising drug in the treatment of primary hyperoxaluria by reducing urinary oxalate (U_Ox). Stiripentol is an anti-convulsive drug used in the treatment of children suffering from Dravet syndrome. It causes blockage of the last step in oxalate production by inhibition of hepatic lactate dehydrogenase 5 (LDH5).

We administered Stiripentol as compassionate use in an anuric infant with dialysis-dependent PH1 over a period of 4 months. Although achieving plasma concentrations of Stiripentol that were recently reported to lower U_Ox excretion, we did not observe significant reduction to plasma oxalate concentrations (P_Ox).

We conclude that Stiripentol may not be useful to reduce P_Ox in PH patients with advanced chronic kidney disease (CKD), but larger studies are needed to confirm this finding.