An orally bioavailable dual receptor tyrosine kinase (RTK) inhibitor with potential antineoplastic activity. EGFR/HER2 tyrosine kinase inhibitor BIBW 2992 irreversibly binds to and inhibits human epidermal growth factor receptors 1 and 2 (EGFR-1; HER2), which may result in the inhibition of tumor growth and angiogenesis. EGFR/HER2 are RTKs that belong to the EGFR superfamily; both play major roles in tumor cell proliferation and tumor vascularization and are overexpressed in many cancer cell types.