An orally bioavailable inhibitor of the extracellular signal-regulated kinases (ERK) 1 and 2, with potential antineoplastic activity. Upon administration, ASTX029 specifically binds to and inhibits both ERK 1 and 2, thereby preventing the activation of mitogen-activated protein kinase (MAPK)/ERK-mediated signal transduction pathways. This results in the inhibition of ERK-dependent tumor cell proliferation and survival. The MAPK/ERK pathway is often upregulated in a variety of tumor cell types and plays a key role in the proliferation, differentiation and survival of tumor cells.