Multi-center phase II study for combination therapy with paclitaxel/doxifluridine to treat advanced/recurrent gastric cancer showing resistance to S-1 (OGSG 0302).

BACKGROUND

A pre-clinical study demonstrated that paclitaxel induced thymidine phosphorylase in the tumor tissues. The combination of paclitaxel and doxifluridine is expected to exert extra anti-tumor effects. We evaluated the efficacy of this combination in patients with unresectable or recurrent gastric cancer who had been previously treated with S-1.

METHODS

Registration was started to enroll 35 patients with advanced/recurrent gastric cancer, who were selected among those with measurable lesions fitting to response evaluation criteria in solid tumors, and with resistant to S-1 treatment. This regimen is consisted of paclitaxel, 80 mg/m(2), iv on days 1 and 8; and doxifluridine, 600 mg/m(2), po on days 1-14. The treatment was repeated every three weeks. Primary endpoint was response rate (RR); and secondary endpoints were overall survival (OS), progression free survival (PFS) and onset rate of adverse events.

RESULTS

From September 2003 to March 2005, 35 patients were registered: including 28 men; 7 women; median age of 66 years (range, 49-75 years); and performance status (PS) levels were, zero with 21 and one with 14 patients. In 33 eligible patients, except two, clinical usefulness was evaluated resulting in RR of 18.2% (partial response, 6; stable disease, 15; progressive disease, 10; and not evaluable, 2 patients). Median survival time was 321 days and median PFS was 119 days. Severe adverse events were found in three patients to discontinue the present treatment.

CONCLUSIONS

The combination of paclitaxel and doxifluridine might be a treatment of choice as a second line chemotherapy for patient undergone S-1 treatment.