An erbB receptor tyrosine kinase inhibitor with potential antineoplastic activity. erbB kinase inhibitor AZD8931 binds to and inhibits erbB tyrosine receptor kinases, which may result in the inhibition of cellular proliferation and angiogenesis in tumors expressing erbB. The erbB protein family, also called the epidermal growth factor receptor (EGFR) family, plays major roles in tumor cell proliferation and tumor vascularization.