Gene Therapy May Reverse Hemophilia
A Single Treatment Allowed Patients With Hemophilia to Stop Regular Injections
Hope on the Horizon for Hemophilia and Other Diseases
So far, researchers have only been able to coax the body to make the protein that helps people with the less common form of the disease, hemophilia B.
But researchers say this approach could work for people who have the more common form, hemophilia A, too. They just need to find the right virus to deliver the genes that would help that disease.
“I think this approach will lead to a cure. I think it’s not there yet,” says study researcher Andrew M. Davidoff, MD, a pediatric surgeon at St. Jude Children’s Research Hospital in Memphis, Tenn.
“We have made a significant impact on the severity of the disease,” Davidoff tells WebMD. “We are looking to cure patients, and I think with improvements in the vector and higher doses, we will be able to cure them.”
Before they were enrolled in the study, the six men all had levels of FIX protein that were less than 1%. After the gene therapy, their FIX levels improved to 2% to 11%.
That’s high enough to prevent spontaneous bleeding events. But it’s not enough clotting factor to keep them out of danger during surgery, for example, or in the event of other significant trauma.
Researchers think they may be able to give people with hemophilia B higher doses of the altered virus to help boost FIX levels even more.
But it’s unclear how much people will be able to tolerate.
In this study, patients who got the highest doses made the most FIX. But they also saw their liver enzymes spike, a sign of inflammation.
“We were able to control this inflammation with a very short course of steroids,” says study researcher Amit C. Nathwani, MBChB, PhD, a hematologist at University College London.
After steroid treatment, liver enzymes returned to normal. And patients continued to make FIX protein on their own, though their levels dropped slightly.
It’s also not clear how long the treatments may last.
All patients who got the gene therapy continue to make FIX protein. Some have been followed for nearly two years.