The U.S. Food and Drug Administration has cleared Jazz Pharmaceuticals Plc’s drug to treat a rare kind of liver disease, making it the first treatment to win U.S. approval for the condition.

The drug, defibrotide, targets patients with hepatic veno-occlusive disease (VOD), a condition in which some of the veins in the liver become blocked, causing swelling and a decrease in blood flow inside the liver, leading to liver damage.

In the most severe form of hepatic VOD, the patient may also develop failure of the kidneys and lungs, the FDA said on Wednesday.