olezarsen
Olezarsen is a monthly subcutaneous antisense oligonucleotide (ASO) developed by Ionis that suppresses hepatic production of apolipoprotein C-III (ApoC-III) — a protein that inhibits triglyceride clearance enzymes — to treat familial chylomicronemia syndrome (FCS). FCS is an ultra-rare inherited disorder in which genetic inability to clear dietary fat causes triglyceride levels exceeding 2,000 mg/dL and recurrent life-threatening pancreatitis attacks; there is currently only one approved therapy, which has limited uptake due to platelet toxicity. An NDA has been filed with a PDUFA date of December 2026; approval would make olezarsen Ionis's first wholly-owned commercial product in the United States.
Upcoming catalysts
Programs
Familial Chylomicronemia
FCS is an ultra-rare inherited disorder caused by biallelic LPL mutations that make patients completely unable to clear dietary fat; triglycerides routinely exceed 880 mg/dL and acute pancreatitis — immediately life-threatening and cumulatively destructive — is the primary clinical consequence. One approved therapy (WAYLIVRA) exists but has limited uptake due to platelet toxicity; olezarsen has filed an NDA with a December 2026 PDUFA and, if approved, would be Ionis's first wholly-owned US commercial product.