Trial expanded for drug therapy first tested at Children’s Hospital

The first large, multi-center trial of a drug developed at Vanderbilt to treat dangerous pulmonary hypertension in children has been launched. The drug, Citrupress, is an intravenous form of the amino acid citrulline, which the body produces naturally and which is also found in watermelon rinds. “About 20,000 or more children every year in the U.S. could benefit from this,” said Rick Barr, M.D., chair of the Division of Pediatric Critical Care and co-inventor of the new drug. “We know about 20 percent of children who have heart surgery with use of the bypass pump develop pulmonary hypertension, or high blood pressure in the lungs. In our early studies we have found our formula appears to prevent pulmonary hypertension from developing.” So far, Barr and colleagues have enrolled approximately 60 children at the Monroe Carell Jr. Children’s Hospital in the study. Beginning this month, seven more medical centers around the country and five international centers will join the study. The goal of enrolling 500 young heart patients could be reached as early as next year, Barr said. “Citrulline is an amino acid we all make in our bodies naturally, and it does exist in large amounts in watermelon,” said Barr. “What we found from our research is that some children, when under the stress of congenital heart defect surgery using the heart/lung bypass machine, slow — or even stop — the production of their own citrulline. We found that was a strong indicator for development of pulmonary hypertension after surgery.” During surgery, a large amount of either Citrupress or placebo is pushed into the fluid circulating in the heart/lung bypass machine. “It’s a key time because it is at the height of the stress on the heart, said Pam Berry, R.N., the research nurse enrolling patients in the Vanderbilt arm of the study. “Then, four to 48 hours after surgery more is administered by IV. At 48 hours, we know most children resume producing their own Citrulline again.” This appears to be the first time a drug formulated at Vanderbilt has made it to Phase III trials under orphan drug status (drugs developed to serve low-frequency diseases). Although early in its testing, no side effects have been noted yet from using Citrupress. The other centers that are now beginning to enroll patients are: Riley Children’s Hospital in Indianapolis, Texas Children’s Hospital, St. Louis Children’s Hospital, the University of California, San Francisco Children’s Hospital, Cincinnati Children’s Hospital, and Hope Children’s Hospital in Chicago. Five hospitals in the United Kingdom, Argentina and Thailand are also involved. News Media – For More Information: Contact: Carole Bartoo, 615-322-4747 Carole.bartoo@vanderbilt.edu