741 Background: Breast cancer is one of the most common malignancies among Chinese women. X (Xeloda) monotherapy has consistently high activity with a favorable safety profile and its addition to docetaxel extends survival in MBC. V has activity in MBC and no overlap in safety profile with X. XV has response rates of 43–67% in MBC, but there are no data in Chinese pts. Methods: 50 pts were planned in this phase II trial conducted between Feb and Nov 2003. All women had prior anthracycline or taxane treatment and measurable (WHO) MBC, adequate Karnofsky PS, bone marrow, renal and hepatic functions. Pts received the recommended doses from phase I studies: X 1000 mg/m2 orally twice daily on days 1–14 and V 25 mg/m2 i.v. on days 1 & 8, every 3 weeks.Results: 36 pts are currently evaluable for safety and 23 for efficacy: median age 49 years (33–69); median Karnofsky PS 80 (range 70–90); most common sites of metastases were liver (47%), lung (44%), and lymph nodes (22%). Prior treatment included anthracyclines (67%), paclitaxel (36%), and docetaxel (28%). All pts received at least 2 cycles, 19 received 4 cycles and 6 have received 6 cycles of XV so far. Interim efficacy findings are shown in the table, with a 44% response rate (so far unconfirmed). Median progression-free and overall survivals have not yet been reached. The only grade 3/4 adverse events reported to date are leucopenia (22%, G3 14%, G4 8%), managed satisfactorily with G-CSF. All other adverse events were easily managed with dose adjustments and supportive therapies where required. Conclusions: XV is a highly active, well-tolerated and convenient regimen in pts with previously treated MBC. Phase III trials of this novel regimen are warranted to demonstrate the utility of adding V to standard X monotherapy. No significant financial relationships to disclose.