Pancreas, x-ray hologram. 3D rendering on dark blue background
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A rare inherited disorder prevents the body from clearing dietary fats from the bloodstream, causing fat levels to soar to dangerous heights. The condition can trigger acute pancreatitis. This is a sudden and severe inflammation of the pancreas that requires emergency hospitalization and can be fatal. The disorder affects a few thousand people worldwide. Most endure repeated attacks over the course of their lives, with no effective treatment available until now.
A new RNA-based drug called plozasiran offers the first real protection. In a controlled trial, a single injection given once every three months reduced the risk of acute pancreatitis by 83%. The drug works by silencing a single gene in the liver. It is part of a new generation of medicines that target the genetic root of a disease rather than managing symptoms.
In a healthy body, fat enters the bloodstream after a meal and clears away within hours. In people with this condition, inherited genetic mutations disable the proteins responsible for removing fat particles from the blood. Fat levels climb to more than 10 times the upper limit of normal. At those levels, fat particles can overwhelm the pancreas. This can cause a sudden, painful, potentially fatal attack.
Daily life for those with these issues centers on restriction. People with this disorder must limit dietary fat to less than 20 grams per day. The threshold is so low that it excludes most ordinary meals. Standard fat-lowering medications do little. The only previously available disease-specific drug caused dangerous drops in blood platelet counts. For people already facing extreme dietary limits and repeated hospitalizations, a treatment with bleeding complications offered a difficult trade.
Plozasiran uses a small piece of synthetic RNA, a molecule closely related to DNA that carries instructions inside living cells. It belongs to a new class of RNA medicines designed to shut down disease at its genetic source.
The body normally produces a specific protein in the liver that slows the removal of fat particles from the blood. To make any protein, a cell first copies the relevant gene’s instructions onto a molecule called messenger RNA. This is a temporary blueprint. The cell reads that blueprint and builds the protein.
Plozasiran interrupts this process. The drug enters liver cells and binds to the messenger RNA encoding the problematic protein. Once attached, an enzyme recognizes the pair and cleaves the messenger RNA. With the blueprint destroyed, the cell stops making the protein. Fat particles then clear from the bloodstream through the body’s natural pathways.
A chemical tag on the drug directs it specifically to liver cells, keeping it out of the rest of the body. That precision is the key difference from the earlier drug. The previous treatment targeted the same gene but reached every organ, causing a dangerous drop in platelet counts. Plozasiran stays in the liver. In the trial, platelet counts remained unchanged.
In the PALISADE study, 75 people with extremely high blood fat levels received either plozasiran or an inactive injection every three months for a year. Plozasiran reduced the risk of pancreatitis by 83%. This reduction held regardless of whether a person had a confirmed genetic mutation. A few people taking plozasiran had small, temporary increases in certain liver enzymes. None were considered dangerous. For people who have spent years restricting every meal and fearing the next emergency hospitalization, plozasiran offers the first evidence that a quarterly injection can reduce the trigger for their most dangerous complication.
The significance of this trial extends well beyond one rare disorder. Plozasiran shows that it is now possible to design a small piece of RNA that turns off a single disease-causing gene in a specific organ. RNA medicines like this one target the root cause of a disease rather than managing symptoms. The same technology is now in development for other serious conditions, including heart disease and immune system disorders. Diseases once considered untreatable now have a path to treatment, one gene at a time.
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