title: Selective inhibition of ADAM metalloproteases blocks HER-2 extracellular domain (ECD) cleavage and potentiates the anti-tumor effects of trastuzumab.
abstract: The HER-2 receptor tyrosine kinase is an important regulator of cell proliferation and survival, and it is a clinically validated target of therapeutic intervention for HER-2 positive breast cancer patients. Its extracellular domain (ECD) is frequently cleaved by protease(s) in HER-2 overexpressing breast cancer patients, rendering the remaining membrane-bound portion (p95) a constitutively activated kinase. The presence of both serum ECD and cellular p95 protein has been linked to poor clinical outcome as well as reduced effectiveness of some therapeutic treatments. We have identified a series of potent, selective small molecule inhibitors of ADAM proteases, exemplified here by INCB003619, and demonstrate that these inhibitors effectively block HER-2 cleavage in HER-2 overexpressing human breast cancer cell lines. Intriguingly, when used in combination, INCB003619 dramatically enhances the antiproliferative activity of suboptimal doses of the anti-HER-2 antibody, trastuzumab, in HER-2 overexpressing/shedding breast cancer cell lines, accompanied by reduced ERK and AKT phosphorylation. Furthermore, INCB003619, in combination with trastuzumab, augments the pro-apoptotic and antiproliferative effects of the chemotherapeutic agent paclitaxel. Consistent with these in vitro data, INCB003619 reduces serum ECD levels and enhances the antitumor effect of trastuzumab in a xenograft tumor model derived from the HER-2 overexpressing BT-474 breast cancer cell line. Collectively, these findings suggest that blocking HER-2 cleavage with selective ADAM inhibitors may represent a novel therapeutic approach for treating HER-2 overexpressing breast cancer patients.
authors.affiliation: Drug Discovery, Incyte Corporation, Wilmington, Delaware 19880, USA. xliu@incyte.com
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Liu
authors.forename: Jordan S
authors.initials: JS
authors.lastname: Fridman
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Eian
authors.initials: E
authors.lastname: Caulder
authors.forename: Gengjie
authors.initials: G
authors.lastname: Yang
authors.forename: Maryanne
authors.initials: M
authors.lastname: Covington
authors.forename: Changnian
authors.initials: C
authors.lastname: Liu
authors.forename: Cindy
authors.initials: C
authors.lastname: Marando
authors.forename: Jincong
authors.initials: J
authors.lastname: Zhuo
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Li
authors.forename: Wenqing
authors.initials: W
authors.lastname: Yao
authors.forename: Kris
authors.initials: K
authors.lastname: Vaddi
authors.forename: Robert C
authors.initials: RC
authors.lastname: Newton
authors.forename: Peggy A
authors.initials: PA
authors.lastname: Scherle
authors.forename: Steven M
authors.initials: SM
authors.lastname: Friedman
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors*; D014183:Transplantation, Heterologous; D000068878:Trastuzumab
chemical_list: D051722:ADAM Proteins; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab