Phase II trial of capecitabine +/- erlotinib in advanced colorectal cancer, with retrospective KRAS and primary tumor site analysis.

781Background: Palliative capecitabine (X) monotherapy for advanced colorectal colorectal cancer (aCRC) is generally well tolerated by elderly or frail pts. Epidermal growth factor receptor (EGFR) monoclonal antibodies improve efficacy when added to combination chemotherapy for mCRC. Erlotinib (E), an oral EGFR tyrosine kinase inhibitor (TKI) may add benefit when added to X. We conducted a randomized phase II trial to investigate the novel “all-oral” combination of X and E in aCRC. Methods: Pts with untreated aCRC who were either deemed unfit for, or chose against, combination chemotherapy were randomized to X (1000 mg/m2 PO BID x 14 days) alone or in combination with E (150 mg PO OD) on a 3-week schedule. Primary endpoint was time to disease progression (TTP); secondary endpoints included: objective response rate (ORR), overall survival (OS), and safety. Tumours were designated as left-sided if there were distal to the transverse colon. KRAS status was retrospectively analyzed for 72 of 82 pts. Results: ...