How does Kynamro (mipomersen) work in the body?
Kynamro works by lowering the body’s production of apolipoprotein B (apo B), which is a key protein in the formation of LDL (“bad”) cholesterol–carrying particles. It is an antisense oligonucleotide designed to bind to the mRNA for apo B in liver cells and reduce apo B production. Lower apo B leads to fewer apo B–containing lipoproteins in the blood, which decreases LDL cholesterol and other related lipids [1].
What does it target, and what happens to apo B and LDL?
Kynamro targets apo B messenger RNA (mRNA) in the liver. After binding, it reduces the message available to make apo B protein, so apo B levels fall. Because many atherogenic lipoproteins require apo B as a structural component, reducing apo B also reduces circulating LDL and related lipoprotein measures used in clinical monitoring [1].
Why does it lower cholesterol specifically in the liver?
Because Kynamro is used to treat certain genetic (inherited) lipid disorders where the liver is the main site driving excess apo B production and high LDL cholesterol. By focusing on apo B mRNA in liver cells, Kynamro shifts lipid production at its source rather than only affecting absorption or clearance in the bloodstream [1].
What’s the practical effect for patients?
The intended clinical effect is a sustained reduction in LDL cholesterol and related atherogenic lipoproteins by lowering apo B production in the liver, which can help reduce cardiovascular risk in people with rare inherited conditions such as familial hypercholesterolemia and familial chylomicronemia (where treatment selection depends on diagnosis and prior therapy) [1].
How is Kynamro different from standard cholesterol-lowering drugs?
Unlike statins (which inhibit cholesterol synthesis) and PCSK9 inhibitors (which increase LDL receptor recycling), Kynamro directly targets the apo B genetic message (mRNA) in liver cells through an antisense mechanism. That “genetic-message” approach is the core difference in how it works [1].
Source
[1] https://www.drugpatentwatch.com/patent/kanamro-mipomersen-mechanism-of-action