The Atlanta-based CDC Foundation has announced a three-year, $3 million grant from Wyeth Pharmaceuticals to study why some hemophilia patients don't respond to drugs currently used to stop or prevent a bleeding episode.

Approximately 7 percent of people with hemophilia, an inherited bleeding disorder that results from deficiencies in the body's blood clotting ability, develop an inhibitor or antibody to the anti-hemophilic drugs that are used to treat a bleeding episode. In the new study, scientists in the Centers for Disease Control and Prevention's hereditary blood disorders unit will collaborate with selected hemophilia treatment centers to gather data about the development of inhibitors and evaluate the risk factors associated with the occurrence. CDC believes that factors such as age, race/ethnicity, type of hemophilia gene defect, frequency of treatment, and the type of drug used for treatment may play a role in the development of inhibitors.

"Little is known about how or why certain individuals develop an inhibitor," said J. Michael Soucie, acting associate director for science in the hereditary blood disorders unit. "We do know that people with hemophilia inhibitors are twice as likely to be hospitalized for a bleeding complication as hemophilia patients without the inhibitor. The cost of hospital care for a bleeding complication is an average of ten times greater for those with inhibitors."