The new era of personalized medicine: 10 years later.

The interest in personalized medicine has increased considerably over the last 10 years with an almost exponential growth in the number of publications since 1999 when the first article discussing the subject appeared. However, the foundation of what we perceive today as personalized medicine had already been created in the 1960s with the discovery of the estrogen receptor, and later on, with the development of the selective estrogen receptor modulator drug - tamoxifen. The key driver in today's personalized medicine is molecular diagnostics, but the need to improve the current pharmacotherapy also plays a very important role. Many of the frequently used drugs are not as effective and safe as they should be. The efficacy rate of drugs within major disease areas such as asthma, cancer, psychiatric illnesses and cardiovascular diseases are in the range of 25-60%. Drug safety is another critical issue which imposes burdens on both patients and society. In the European Union, it is estimated that 5% of all hospital admissions are due to side effects related to pharmacotherapy, thus resulting in nearly 200,000 deaths per year. The total cost related to side effects from therapeutic drugs in the European Union is €79 billion per year. This situation needs to be improved, and this can be achieved by taking differences in the individual patient's biologies into consideration when the drugs are dispensed. A more individualized pharmacotherapy by the implementation of pharmacodiagnostic testing will be an important aid in improving efficacy and reducing the frequency of serious side effects in the future. However, there are obstacles to be overcome with regard to the implementation of personalized medicine, and besides scientific and economic issues, it will be a challenge to address other aspects, such as regulatory requirements, reimbursement, education and logistics.