Two new studies could pave the way to major changes in how doctors treat severe cases of hemophilia — a rare genetic disorder that can cause uncontrolled bleeding.
Both studies tackle a key challenge: Up to one-third of children with severe hemophilia develop antibodies against the standard therapy.
But one study highlights the value of an old therapy, while the other shows promising early results with an experimental drug.
Experts said both should stir discussion among doctors, patients and parents who deal with hemophilia. But they were especially hopeful about the new drug, known as emicizumab.
In the United States, about 20,000 people — mostly boys and men — are living with hemophilia, according to the U.S. Centers for Disease Control and Prevention.
The disorder is caused by a defect in one of the genes that controls proteins needed for normal blood clotting. Most people have hemophilia A, which means they lack a protein called factor VIII. In severe cases, they have little to no factor VIII in their blood.
The standard treatment is to replace the protein through intravenous infusions done at home.
Years ago, that replacement protein came exclusively from donor blood. “That worked well until the 1980s and the HIV epidemic,” said Dr. Christopher Walsh, director of the hemophilia program at Mount Sinai Hospital, in New York City.
Between the late 1970s and mid-1980s, half of Americans with hemophilia became infected with HIV through contaminated blood products, according to the National Hemophilia Foundation.
That led to the development of genetically engineered “recombinant” factor VIII.