Professor David Webb: Drug development critical in ongoing medical challenges

Published on Monday 20 July 2009 19:00

OVER the past 50 years the use of effective medicines to treat heart disease, cancer and infections has transformed and extended our lives.

Now that most medicines for the more easily treated conditions have been discovered, it is harder to find new drugs that will bring major benefits for large numbers of people. In addition, medicines are increasingly being used as a preventative measure in patients deemed at higher risk of future illness, such as treatments for raised cholesterol or blood pressure. There is, however, a reduced willingness among patients to accept the low risk of side effects of preventative medicines when compared with potential future benefits.

An international medical congress of the European Association of Clinical Pharmacology and Therapeutics held in Edinburgh last week drew together 1,000 delegates from 50 countries to address how best to use existing medicines and to develop new ones.

A major theme was drug discovery and development. The mapping of the human genome and the identification of a range of new drug targets was expected to produce large numbers of new medicines over the last few years. However, the number of new medicines submitted for licences has fallen substantially. It may be that it will take many more years to reveal the secrets of the genome sufficient to translate them into new medicines. On the other hand, it may be that we need to identify sub-groups of patients with common conditions, such as high blood pressure, who differ subtly from others with the same condition and who share a genetic mechanism that enables them to respond better to a new drug than patients without this genetic marker.

There was agreement that universities need to be re-engaged with industry in identifying the best targets for medicines and in efficient drug development to the point of licensing. Universities have always been strong in uncovering the mechanisms of bodily function, and the associated biochemical pathways and mediators, which provide the source of new targets for medicines. Universities are also very strong in the early human research that helps define the likely benefits that a new medicine might provide. Professor Garret FitzGerald, of the University of Pennsylvania, a world leader in this field, argued that universities need to regain this ground of 'translational' medicine (translating research from the lab to the clinic) for the more efficient and effective drug development.

It also seems that regulation may need to become more flexible to allow a broader use of medicines, while collecting ongoing information about their safety to ensure a reasonable balance between harms and benefits. It was argued that withdrawal of medicines will also need to become more flexible, with global withdrawal being less often used. In future, regulators may make more effort to provide information on benefits and side effects to patients so that they can decide whether or not to take them.

An area where genetic makeup (genotype) may be widely important in the near future, and where there have already been examples of success, is identifying patients in whom an effective medicine may have a much higher chance of causing serious side effects (such as abacivir in HIV). Identifying such patients will enable them to avoid certain drugs and have alternative treatments. This is probably the major area in which the benefit/harm balance can be optimised for an individual (so-called 'personalised' medicine).

A key strand running through the meeting covered the need to prepare medical practitioners for prescribing. We now have more medicines than ever before, they are more complex and more powerful, and they are often taken in combinations that may interact. With an increasingly elderly population, where drug interactions and side effects are more common and serious, it is clear that this needs attention. Indeed, this is the commonest area in which patients come to harm as a result of errors by clinical staff. There was broad agreement that the practical skill of prescribing needs to be underpinned by knowledge and a scientific understanding of the principles of drug action, with this being central to the medical education curriculum.

&#149 David Webb is professor of therapeutics and clinical pharmacology at the University of Edinburgh and president of EACPT 2009