An orally available inhibitor of extracellular signal-regulated kinase (ERK) 1 and 2, with potential antineoplastic activity. Upon oral administration, temuterkib 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 tumor cell proliferation, differentiation and survival.