Table 2.

Key events in the discovery of the first two waves of epigenetic drugs

	DNA methyltransferase inhibitors
1964	Azacitidine and decitabine synthesis
1967	Azacitidine enters clinical trials
1980	Azacitidine and decitabine identified as DNMT inhibitors
1980	Decitabine enters clinical trials
2004	Azacitidine FDA approval
2006	Decitabine FDA approval
	Histone deacetylase inhibitors
1971	DMSO reported as differentiation agent
1976	Bisamide precursor to SAHA (vorinostat) reported as differentiation agent
1990	Trichostatin A identified as HDAC inhibitor
1990	Romidepsin reported as a natural product
1996	Vorinostat synthesis
1997	Romidepsin enters clinical trials
1998	Vorinostat and romidepsin identified as HDAC inhibitors
2000	Vorinostat enters clinical trials
2006	Vorinostat FDA approval
2009	Romidepsin FDA approval
2014	Belinostat FDA approval
2015	Panobinostat FDA approval
2015	Chidamide China’s FDA approval