What is being touted as the "first ethnic drug"--a heart drug for African Americans--is about to be tested in clinical trials. NitroMed, a company in New Bedford, Massachusetts, announced earlier this month that it has won Food and Drug Administration (FDA) clearance for an all-black clinical trial.
In the United States, blacks are more likely than whites to develop congestive heart failure and are roughly twice as likely to die of the disease. Nor do they benefit as much from the frontline drug therapy, known as ACE inhibitors. These drugs interfere with a metabolic process that causes blood vessels to constrict, raising blood pressure. However, the drug is more effective if patients respond with a strong increase in circulating nitric oxide (NO). Black patients may have an inherited physiological difference that causes them to respond to ACE inhibitors with lower NO levels than whites, limiting the effect, says Jay Cohn, a heart researcher at the University of Minnesota, Twin Cities.
BiDil--which combines two vasodilators with a source of NO--may help, says Cohn, who invented the drug and licensed the rights to NitroMed in 1999. Although BiDil had little effect on overall mortality in a study done in the 1980s, Cohn's analysis of a subset of black patients suggests that they benefited. Based on this, FDA agreed to a 2-year trial that will compare BiDil and other drugs with a placebo on 600 black patients at 100 sites.
Other researchers are intrigued but wary. "I'm skeptical of the approach," because it substitutes skin color for genetic analysis, says Marc Pfeffer of Harvard's Brigham and Women's Hospital in Boston. Conceding the point, a NitroMed official says "we're searching for a better diagnostic" to target the therapy.