Hypoxia-inducible factor (HIF) inhibitors: a patent survey (2011-2015)

Introduction: Hypoxia-inducible factor (HIF)-1 alpha regulates the expression of genes involved in angiogenesis, cellular energy metabolism, and cell survival during cancer development. The increased expression of HIF-1 alpha in most solid tumors is associated with poor prognoses and therapeutic outcomes. Therefore, HIF has been recognized as an attractive target for cancer therapy, and many HIF inhibitors have been reported. Areas covered: This patent survey summarizes the information about patented HIF inhibitors over the last 5 years (2011-2015). Expert opinion: Although many of the HIF inhibitors reviewed in this patent survey possess inhibitory activity against cancer and HIF-related diseases, the compounds are still in the early stages of development, most likely due to the complexity of the HIF-1 pathway and their different mechanisms of action for HIF inhibition. Most cancer cells use the glycolytic pathway for energy production and HIF-1 alpha participates deeply in the expression of several glycolytic enzymes. Therefore, a detailed study of HIF's function in cancer metabolisms may provide us an alternative strategy for further development of HIF inhibitors in cancer therapy.