Biological networks and drug discovery--where do we stand?

The progress in genomics and molecular biology during the last decade has led to the insight that complex diseases are caused by defects in many genes and that cellular processes are organized in complex networks. In the search of new drugs, these findings have not yet been fully taken into account. The currently predominating drug discovery approach in pharmaceutical industry is still target-centric, with the goal to optimize compounds toward high affinity and selectivity for a specific target. There is growing evidence that the successful development of effective disease-modifying medications needs a network approach instead. This might also help to reduce the very high failure rate in the current drug development process. This review outlines concepts and applications of network biology and routes toward drugs that are designed to interact with several targets. Obstacles to the implementation of this approach in the pharmaceutical industry are discussed.