FDA Clears Drug that Treats Inherited High Cholesterol

Kynamro has officially been approved by the U.S. Food and Drug Administration to treat a rare, inherited disease. The DNA-linked condition keeps the body from removing low-desnity lipoprotein (LDL) cholesterol from the blood.

Many people with the inherited inability to remove LDL have a heart attack and die before age 30. The condition, called homozygous familial hypercholesterolemia (HoFH), affects approximately one of every one million people in the U.S. LDL is the so-called "bad" cholesterol that can clog arteries and cause heart attack and stroke. HoFH can cause people to have cholesterol levels that are two to four times higher than normal.

Yet Kynamro may soon be able to help these people. It's a once-weekly injection designed to lower the creation of blood lipid particles that eventually form LDL, according to the FDA.

The drug was evaluated among 51 people with HoFH. Researchers found that LDL levels fell an average of 25 percent during the first 26 weeks for people who used Kynamro.

However, the drug bottle will have a warning label about its risks for liver toxicity. In late-stage trials of drug testing, 8 percent of patients who took Kynamro experienced elevated levels of an enzyme that indicates liver damage. Since Kynamro can lead to flu-like symptoms and liver damage that deter patients from continuing treatment, the drug failed to win European Union backing in December. In addition, the FDA is requiring four postmarketing studies for Kynamro, including programs to monitor the safety of the drug.

More common side effects of the drug noted during clinical testing were injection-site reactions, flu-like symptoms, nausea, headache, and elevated liver enzymes.