Emerging therapies in gastrointestinal cancers

Table 2 Selected ErbB-targeted small molecule inhibitors

Drug/agent	Molecular properties	Target Selectivity	Clinical activity in cancer type	Company/Institution	Stage of development
Gefitinib (ZD 1839; Iressa)	Reversible TKI	EGFR inhibitor	NSCLC, HNSCC, colorectal cancer and breast cancer	AstraZeneca	Approved for NSCLC in 2003, ongoing Phase III Trials for other cancers
Erlotinib (OSI-774; Tarceva)	Reversible TKI	EGFR inhibitor	NSCLC, HNSCC, colorectal cancer and pancreatic cancer	Genentech/ OSI pharmaceuticals	Approved for NSCLC in 2005, ongoing Phase III Trials for other cancers
Canertinib (CI-1033)/(PD183805)	Irreversible TKI	EGFR/ErbB-2 inhibitor	NSCLC, HNSCC, Ovarian cancer, breast cancer	Pfizer	Phase II
Lapatinib (GW2016)	Reversible TKI	EGFR/ErbB-2 dual inhibitor	Breast cancer	GlaxoSmithkline	Phase III
EKB-569	Irreversible TKI	EGFR inhibitor	Colorectal cancer, cancer, HNSCC, and NSCLC	Wyeth-Ayerst	Phase II
AEE788	TKI	EGFR/ErbB-2/VEGFR	Anti-proliferative effects in tumor cell lines and animal models of cancer	Novartis	Phase I
EXEL 7647/EXEL 0999	TKI	EGFR/ErbB-2/VEGFR		EXELIXIS	Phase I
PKI-166	Reversible TKI	EGFR/ErbB-2	Thyroid, Renal, colorectal, HNSCC, and NSCLC	Novartis	Phase I
PD 168393	Irreversible TKI	EGFR	-	Calbiochem	Preclinical
AG-1478	Irreversible TKI	EGFR	-	Calbiochem	Preclinical
CGP-59326A	Reversible TKI	EGFR	-	Novartis/	Preclinical
BIBX 1382	TKI	EGFR	-	Boehringer/Ingelheim	Preclinical

EGFR: epidermal growth factor receptor; TKI: tyrosine-kinase inhibitor; NSCLC: non-small-cell lung cancer; HNSCC: head and neck squamous-cell cancer, VEGFR: vasculo-endothelial growth factor receptor.