[On the molecular drug design from viewpoint of precision medicine]

Precision medicine (PM) involves the application of "omics" analysis and system biology to analyze the cause of disease at the molecular level for targeted treatments of individual patient. Based on the targeted treatment PM is closely related to pharmaceuticals, which, as a therapeutic means and supply front, mainly embody the two aspects: drug discovery/development, and clinical administration. Innovation of new molecular entities with safety and specific efficacy is the prerequisite and guarantee for the PM practice; on the other hand, the outcome and clues in clinical PM feedback to new drug research. PM and drug research/application are interdependent and promote each other. Aimed at precision medicine, drug discovery and development involve well-known contents: the discovery and validation of targets, the association between target functions and indications (proof of concept), lead discovery and optimization, the association between preclinical investigations and clinical trials, the lean of industrialization and pharmacoeconomics. At the molecular level the therapeutic efficacy originates from the interactive binding between specific atoms or groups of the drug molecule and the complementary atoms or groups of the macromolecular target in three-dimensional space. The strict arrangement of such critical atoms, groups, or fragments reflect specific features for a precise binding to the corresponding target. An alteration of amino acid residues in mutational targets leads to the change in conformation of the target protein, and an accurate structure of drug is necessary for binding to the mutant species and avoiding off-targeting effect. For the tailoring of clinical treatment to the individual patient design and development of various new molecular entities are critical for treatment choice according to the molecular features of biological markers of patients. This article provides some examples and methods of drug design and development in the new period.