I think the FDA had enough statisticians, so maybe it's a FDA Political Correctness boo boo in that they didn't do a subset analysis. From the article:
BiDil is a combination of two old generic drugs, neither of them approved for heart failure. Jay N. Cohn, a professor at the University of Minnesota School of Medicine, first thought of combining them to treat heart failure in the 1970's, and a trial was conducted in the early 1980's.
That trial showed the drug to have some effect, but the Food and Drug Administration rejected the drug, arguing the data were not strong enough. After Medco Research, a company that had licensed the drug, dropped it, the rights reverted to Dr. Cohn. NitroMed, which was interested because the drug fitted its focus on nitric oxide, licensed it in 1999.
Reviewing the data from the old trial, Dr. Cohn and NitroMed found that the drug had been remarkably effective in the subset of patients who were black.
Three cheers for Dr. Cohn's persistence and insight!!!