Ionis Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug designation to the investigational medicine olezarsen for the treatment of familial chylomicronemia syndrome (FCS), a rare, genetic disease characterized by extremely elevated triglyceride levels and recurrent acute pancreatitis (AP). The FDA grants Orphan Drug designation to therapies intended for treatment, prevention or diagnosis of a rare disease or condition that affects fewer than 200,000 people in the U.S. at the time of designation. FCS prevents the body from breaking down fats, which can result in fasting triglyceride levels that can range from 10 to 100 times higher than normal levels.

People with FCS are at high risk of AP, or inflammation of the pancreas, which often results in hospitalization and can be life-threatening. In severe cases, vital organs such as the heart, lungs, kidneys and pancreas can be damaged. Under the FDA's Orphan Drug Act, orphan drug status provides incentives, including tax credits, grants and waiver of certain administrative fees for clinical trials, and seven years of market exclusivity following drug approval.

Olezarsen is an RNA-targeted investigational LI gand C onjugated A ntisense (LICA) medicine being evaluated for people at risk of disease due to elevated triglyceride levels, including those with familial chylomicronemia Syndrome (FCS). Olezarsen is designed to inhibit the body's production of apoC-III, a protein produced in the liver that regulates triglyceride metabolism in the blood. The U.S. FDA granted olezarsen Fast Track designation for the treatment of FCS in January 2023.

In addition to FCS, Ionis is evaluating olezarsen for thetreatment of severe hypertriglyceridemia (sHTG) in Phase 3 clinical trials. FCS is a rare, genetic disease characterized By By-laws, Ionis is evaluating ozarsen for the treatment of severe hypertrig triglyceridemia (sHTG). It is caused by impaired function of the enzyme lipoprotein lipase (LPL).

Because of limited LPL production or function, people with FCS cannot effectively break down chylomicrons, lipoprotein particles that are 90% triglycerides. FCS is estimated to impact one to two people per million worldwide. People living with FCS is at high risk of acute pancreatitis (AP) in addition to other chronic health issues such as fatigue and severe, recurrent abdominal pain.

People living with FCS are sometimes unable to work, adding to the burden of disease. Currently, there are no U.S. FDA-approved therapies for the treatment of FCS and standard triglyceride lowering therapies are generally ineffective in patients with FCS. People living with this condition currently rely solely on nutrition management through extremely restrictive and difficult to adhere to diets to navigate the health risks associated with FCS.