A phase II multicenter, double-blind, randomized trial to compare anastrozole plus gefinitib with anastrozole plus placebo in postmenopausal women with hormone receptor-positive (HR+) metastatic breast cancer (MBC)

1012 Background: Preclinical data provide evidence that suggests crosstalk between growth factor receptor pathways and the estrogen receptor (ER). Inhibition of both epidermal growth factor receptor and ER signalling may thus be a potential intervention to overcome hormonal resistance. We performed a phase II study to evaluate efficacy and tolerability of anastrozole (Arimidex) plus gefitinib (IRESSA) [A+G] vs. anastrozole plus placebo [A+P] for treatment of newly diagnosed HR+ MBC in postmenopausal women. Methods: A total of 94 women with newly diagnosed HR+ MBC were randomized (1:1) (one woman died prior to treatment) to receive anastrozole 1 mg/day and either gefitinib 250 mg/day or placebo (50 to A+P; 43 to A+G). Hormone receptor status was reviewed at a central laboratory. Primary endpoint was progression-free survival (PFS) and secondary endpoints included objective response rate (RECIST criteria) and clinical benefit rate (CBR; defined as objective response or stable disease ≥24 weeks), overall sur...