Besides providing a new way to redefine human diseases and gain a broader understanding of disease mechanism, the genomic profile-based disease relationship can also help us to find potential new indications of existing drugs.
In summary, our study demonstrated that gene expression signature-based in silico drug discovery is potentially valuable for the identification of new indications of existing compounds, which is critical for translational research and clinical applications.
However, in many cases, new indications of existing drugs have been found serendipitously.
In particular, sequence and structural similarities among drug targets have been successfully utilized to find new clinical indications of existing drugs [ 16].
This is a systematic process to identify new medicines or new indications of existing medicines that are expected to receive marketing authorisation from the Regulatory Authority in the near future and to estimate their potential impact on patient care [ 16].
One strategy which seems to work well is to apply approaches of drug repurposing where it is crucial to understand the mechanism of disease manifestation and subsequently applying various modeling approaches to find new indications of existing drugs in the market (http://www.fda.gov/ForIndustry/DevelopingProductsforRareDiseasesConditions/HowtoapplyforOrphanProductDesignation/ucm216147.htm).
Many previous studies tried to find novel candidate indications of existing drugs, but these works have following limitations: 1) models are not fully automated which required manual modulations to desired tasks, 2) are not able to cover various biomedical entities, and 3) have inference limitations that those works could infer only pre-defined cases using limited patterns.
Motola et al 13 considered all drugs approved by the European Medicines Agency (EMA) between 1995 and 2003 according to an algorithm that considered the severity of the target indication, availability of existing treatments and size of therapeutic benefit.
Detailed clinical and laboratory history of patients undergoing treatment contained in EMR may reveal new indications or contraindications of existing therapeutics.
