Some scientists believe that race is too broad and ill-defined a category to be relevant in determining a drug's approval.

The heart-failure treatment drug called BiDil was rejected by the Food and Drug Administration because its supporting studies were found to be inconclusive, The New York Times reported Monday.

But now a study of 1,050 African-American heart failure patients showed BiDil significantly reduced death and hospitalization, the Times reported.

'Based on Solid Science'

BiDil is seen as increasing the levels of nitric oxide, which widens blood vessels. Previous studies have suggested African-Americans have deficiencies of nitric oxide, a compound that occurs naturally in the human body, the report said.

The drug's maker, NitroMed Inc., says its decision to market BiDil for African-Americans is based on solid science. But other scientists think that race is too broad and ill-defined a category to be relevant in determining a drug's approval, the Times said.