NEW YORK — The Food and Drug Administration approved a drug Tuesday that not only treats a rare inherited disorder that causes extremely high cholesterol levels and heart attacks by age 30 but does so using a long-sought technology that can shut off specific genes causing disease.
The drug, Kynamro, which was invented by Isis Pharmaceuticals and will be marketed by Sanofi’s Genzyme division, is unlikely to be a blockbuster. It has some worrisome side effects, and there might be no more than a few hundred people in the United States with the disease, known as homozygous familial hypercholesterolemia. Genzyme is based in Cambridge.
Kynamro could become the first commercial success for the gene-silencing technique known as antisense, which some experts say is poised to fulfill its promise after decades of research.
“What many people have been waiting for is validation where someone actually makes a profit and where patients actually benefit,’’ said Arthur M. Krieg, chief executive of RaNA Therapeutics, an antisense drug developer in Cambridge.