PRX-ASL

**PRX-ASL** is an intracellular enzyme replacement therapy (i-ERT) developed using PhaseRx's proprietary Hybrid mRNA Technology to deliver mRNA encoding functional human argininosuccinate lyase (ASL) enzyme specifically to liver cells. It addresses argininosuccinate lyase deficiency (ASLD), a rare urea cycle disorder caused by ASL gene mutations leading to hyperammonemia, elevated plasma citrulline, argininosuccinic acid, and risk of neurological impairment, coma, or death. Preclinical studies demonstrated reduction in these toxic metabolites and therapeutic potential, with orphan drug designations from FDA (2017) and positive opinion from EMA.[1][2][3][5][7]