Bad blood
UF researchers work to improve treatments for people who have hemophilia
By Czerne M. Reid
Hemophilia patient Andrew Xiong, 3, gives a Valentine's Day card and a box of candy to "Dr. Number," the nickname he has for Dr. Levette Dunbar, the UF pediatric hematologist-oncologist he sees regularly while his mother Xiaoxia Wei looks on./Photo by Jesse. S. Jones
Daily life can be hazardous to 3-year-old Andrew Xiong’s health. Simple bumps and bruises can lead to internal bleeding that can land him in the hospital. Andrew has hemophilia, a disorder in which the blood has difficulty clotting because of a defective gene.
William “Max” McBrayer, 7, also has been in and out of the hospital since he was 9-and-a-half months old because of hemophilia.
William (Max) McBrayer, 7, is tickled by his mother Wendy while playing video games in his room in the Shands at UF./Photo by Jesse S. Jones
Both boys get frequent injections of the blood-clotting protein their body doesn’t produce, and without which they bleed easily and profusely.
“It’s scary, because you don’t know if it’s going to stop,” said Max’s mother, Wendy McBrayer. “I’m hoping that there is going to be a cure one day.”
Researchers at UF are already working hard to develop new therapies for improving the health and quality of life for people like Andrew and Max. Treatments already in use are often rejected by patients’ immune systems and can cost up to $1 million per round.
The UF researchers, all faculty members in the department of pediatrics division of cellular and molecular therapy, the UF Genetics Institute and the Powell Gene Therapy Center, are supported by a number of grants from the National Institutes of Health and Bayer HealthCare, totaling more than $6 million.
“The portfolio of grants allows UF to build and sustain a robust hemophilia research program covering both forms of the disease, hemophilia A and B, and fulfill an unmet need in Florida and the region,” said Roland Herzog, Ph.D., an associate professor who is principal investigator on three NIH grants and co-investigator on two Bayer awards.
The other principal investigators are Arun Srivastava, Ph.D., the George H. Kitzman professor of genetics, and associate professor Sergei Zolotukhin, Ph.D.
The grants fund the researchers’ efforts to develop and test gene therapy methods for both forms of the disease and to find ways to deliver the clotting factor protein orally and prevent the immune system from rejecting gene or protein therapies. Some of the work is in collaboration with the Wistar Institute, the Children’s Hospital of Philadelphia, Harvard Medical School and the University of Central Florida.
Sergei Zolotukhin, Arun Srivastava and Roland Herzog/Photo by Jesse S. Jones
About 1 in 5,000 boys are born with hemophilia A, the more common form, which both Andrew and Max have. Standard treatment is IV infusion of the missing protein. But in 25 percent of patients with the severe form of hemophilia, the immune system rejects the clotting protein. To help patients tolerate therapy, doctors try to exhaust the immune system by administering the therapeutic protein intravenously until the body no longer responds with inhibitors. That brute force approach works for hemophilia A, but can cause life-threatening allergic reactions in hemophilia B.
“New and safer ways to deliver therapy would be far more welcome than what we’re doing now,” said Vishwas Sakhalkar, M.D., director of benign hematology in the division of pediatric hematology/oncology, who treats patients with hemophilia and other blood disorders. “Patients, their families, caregivers and doctors will embrace those advances, after seeing all that patients have to go through now for treatment.”
Andrew is already looking toward his future. He wants to become a doctor — just like “Dr. Number,” as he calls Levette Dunbar, M.D., the UF pediatric hematologist-oncologist he sees regularly.