RACE DRUG

Doctors could soon be prescribing the world's first race-specific drug amid a storm of controversy. Regulators in the US are being asked to approve a heart failure treatment for black people only. The application has already sharply divided those who see the move as a big step forward, and others who think race has no place in medicine. A panel of US Food and Drug Administration (FDA) experts will decide whether to recommend granting the licence. The likelihood is that the agency will approve the therapy in some form, New Scientist magazine reported. But the issue was set to spark "one of the most explosive rows the FDA has ever faced".

The drug, BiDil, is said to work much better in African Americans than in whites. Its makers, the Boston biotech company NitroMed, claims this is due to biological differences between the two groups. Afro-Americans have lower levels of nitric oxide in their blood vessels and are more prone to high blood pressure. Critics point to the fact that black Americans are generally less healthy anyway because of poverty and poor access to health care. Research has also shown that rural Nigerians have much lower blood pressure than African Americans or even white Europeans.

Nonetheless, trials found that BiDil improved survival by 47% in black patients but only by 15% in whites. A study of 1,050 people who identified themselves as African Americans showed that treating heart failure with BiDil combined with standard therapies reduced annual death rate by 43%. BiDil is a mixture of two drugs which together raise levels of nitric oxide, a signalling molecule that causes blood vessels to dilate and reduce strain on the heart. Low nitric oxide levels are known to contribute to high blood pressure, which is more common in Afro-Americans. Long-term high blood pressure is one of the causes of heart failure, which occurs when the heart cannot pump blood around the body forcefully enough.

Other causes of the condition are narrowed arteries or heart muscle damaged by a heart attack. Patients generally deteriorate over time and have an annual death rate of 10% to 20%. NitroMed's chief medical officer and cardiologist Manuel Worcel told New Scientist, "Heart failure is a catastrophe. So, when you have a drug that saves around half of patients, this is huge progress. There has been a lot of controversy, but we know we have to take ethnic origin into account." Opponents of the move argue that NitroMed is simply trying to find a market niche for the drug, which performed less well than a standard therapy in a trial involving both white and black patients.

Jonathan Kahn, of Hamline University in St Paul, Minnesota, USA, an expert in the legal and ethical issues surrounding medicine, said, "Some people talk about heart failure as a different disease in blacks in what I can only describe as an irresponsible manner. It fuels talk about how races are genetically different. This is very unfortunate and dangerous." In 1972, Richard Lewontin, a geneticist at Harvard University, reported far less variation between different races than between individuals of a single race. Any differences between ethnic groups were literally skin deep, he said. Yet doctors have long known that certain diseases are more common in some populations than others.

The blood condition sickle-cell anaemia, for instance, is most common in people from Africa, the Caribbean, the eastern Mediterranean, the Middle East and Asia. Cystic fibrosis is more common in whites than in blacks, and prostate cancer in people of African descent. Asthma is much more prevalent and difficult to treat in Puerto Rican children than in those from other ethnic groups, or even sub-groups. Puerto Ricans suffer more from asthma than Mexicans, even though both are Hispanic. Breast, ovarian and prostate tumours caused by two genetic mutations are most common in Ashkenazi or East European Jews. One in 40 of them carries one of these genes, compared with one in 500 of the general population.

Some critics fear that race-specific approval will lead doctors to assume that only dark-skinned people respond to the drug. "The problem is, when you racialise, there are going to be many white people who could have benefited from the drug not being prescribed it, and many black people who have a different kind of response to the drug being given it," said Troy Duster, a sociologist at New York University. (Source: Mail on Sunday)