Pharmacogenetics
Pharmacogenetics and racial groups
25 A particular case of the stratification of patient populations is stratification based on racial or ethnic groupings. Race and ethnicity cannot be given precise biological or genetic definitions. There is considerable genetic variation within racial and ethnic groups, whether defined by place of birth, self-identification or other criteria, as well as between them. Nonetheless, some genetic variants are more common in some racial or ethnic groups than in others. This has implications for the design of clinical trials and for the development of medicines and pharmacogenetic tests. Trials conducted in different countries, or statements about efficacy based on evidence in one particular population, may not be valid in other, genetically different populations, or may only be valid if a different prevalence in relevant genetic variants has been taken into account. We recommend that bodies giving approval for the clinical use of pharmacogenetic tests require these to specify the population groups in which the tests have been validated, and to issue warnings where there is evidence that such tests may not be usefully predictive of response to medicines in other population groups (paragraph 4.43).
26 Acknowledging that genetic variation between population groups should be taken into account in the design of medical research should not be taken to imply that there are sharp lines that can be drawn between groups on the basis of genetic information which coincide directly with racial categories. Particularly in countries where medicines are advertised directly to consumers, there is a risk that medicines could be marketed to particular racial groups in a misleading manner, giving the impression that all members of that group would be likely to benefit, or that the medicine was more effective than other, non-racially defined, medicines. More generally, such developments may reinforce tendencies to view race as a biologicallydefined phenomenon. We recommend that those involved in pharmacogenetic research and the development of new medicines should be sensitive to the potential for misunderstanding and prejudice arising from racial stereotyping. We recommend further that regulatory bodies exercise careful scrutiny over claims as to racial specificity in the marketing of pharmacogenetic tests and medicines (paragraph 4.45).
27 Denying treatment to a particular racial group, using race as a proxy for a genetic profile, would be problematic, since not every member of the group could be expected to have the genetic variant in question. It is possible that health professionals would be tempted to use race as a proxy in determining treatment, if the pharmacogenetic test that would discriminate more accurately was not readily available. Since clear-cut divisions between racial or ethnic groups are highly unlikely, we take the view that membership of a particular racial group should not be used as a substitute for a pharmacogenetic test, even if it is the case that the genetic variant being tested for is known to be more or less prevalent in particular groups (paragraph 4.46).
28 A further potential problem arises if stratification results in the members of some ethnic groups finding that they are denied access to medicines when others of different ethnic groups, but suffering the same condition, are allowed access. This would be a particular cause for concern if the group being denied treatment was already socially and medically disadvantaged. At the present stage of development, we cannot say how great a problem this is likely to be. However, it is something that should be monitored. We recommend that those responsible for monitoring the relative access of different ethnic groups to treatment in the National Health Service (NHS) establish procedures for assessing whether problems emerge arising from the development and application of pharmacogenetics (paragraph 4.47).