No two people are identical. And no two patients are identical. In an ideal world, every patient should have exactly the treatment that is right for him or her and be prescribed the medication that is individually suited to his or her specific condition. Therapies should show precisely the effect that is intended, and have few if any effects on the patient's quality of life. This goal is ambitious and cannot be met in every case.

One of the reasons why truly individualised therapies, or ‘personalised healthcare’, may still be a distant prospect is the mere complexity of science. Almost every day, researchers are bringing to light new findings about molecular-biological causes and connections of diseases. These findings radically change the general conception of complex diseases. For example, the term ‘breast cancer’ indicates a great many cancerous conditions, which all originate differently, follow a different course and so must be treated differently. Rheumatism is another example. The collective term covers a very wide range of different conditions, including inflammatory and autoimmune diseases. In virology, too, conditions such as hepatitis C can be further differentiated, e.g. depending on the particular strain of virus.

At the same time, these scientific advancements have the potential to improve the ways to differentiate among different patient groups and more clearly define the root of an illness. Genomics (the study of genes and their function), in particular, provides insights into inherited and biological conditions. Given these advances, treatments that are focused on specific requirements of certain patient groups seem possible – while also avoiding undesirable side effects.

‘Therapeutic stratification’ is the term experts are using to discuss this important field. In contrast to the one-size-fits-all principle, stratification means customising new or existing therapeutic agents more precisely, with the help of genetic profiles of the person or specific patterns of disease, for their effect on certain patient groups. This means treating those that benefit most with the right therapy.

As well as improving the effectiveness of a medicine this should also have a positive impact on patient safety. Better targeting medicines will help us to identify those patient groups that might not fully benefit from a medicine or that could develop undesirable side effects. As this will be known before exposing patients to a medicine, their physician will be able to recommend alternative treatments without putting them at risk.

Roche has the opportunity to be one of the first companies to make therapeutic stratification an integral part of the development and marketing of new medications. This will ultimately lead to better, safer medicines which benefit not only the patient, but society in general.