P-170 Biweekly S-1 and nab-paclitaxel as first-line chemotherapy in patients with unresectable or recurrent gastric cancer

Abstract

Introduction: Palliative chemotherapy has been shown to have a survival benefit for patients with unresectable or recurrent gastric cancer.We conducted a phase II trial to determine the efficacy and safety of S-1 plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as a first-line chemotherapy for patients with unresectable or recurrent gastric cancer. Methods: Eligible patients had measurable or evaluable lesions and no previous history of chemotherapy (except adjuvant chemotherapy). Nab-paclitaxel was administered intravenously at a dose of 200 mg on day 1. S-1 was administered orally at doses of 80, 100, or 120 mg/day according to body surface areas of <1.25, 1.25-1.5 or >1.5 m2, respectively; the total dose was divided into two daily doses on days 1-10. Treatments were repeated every 2 weeks. Combined treatment was continued to no more than 9 cycles. Then, S-1 was given as maintenance treatment until disease progression or study discontinuation. Results: From May 2012 to September 2014, 36 patients were enrolled. One patient withdrew from the trial because of cerebral infarction after one cycle of treatment. Two patients withdrew informed consent.26 patients were measurable for responses. The overall response rate was 50% (13/26,95% confidence interval [CI], 29.9-70.1%). The disease control rate was 76.9%( 20/26,95% CI, 56.4-91.0%) among measurable patients and 81.8%(27/33,95% CI, 64.5-93.0%) among evaluable patients, respectively. Three patients had a radical gastrectomy after chemotherapy. The median progression-free survival and overall survival were 6.5 months (95% CI, 4.5-8.5months) and 13 months (95% CI, 8-18 months), respectively. The most common grade 3/4 toxicities were neutropenia (25.7%), Thrombocytopenia (12.9%), Leucopenia (5.7%), and Anaemia (2.9%). There were no grade 3/4 non-hematotoxicity. No treatment-related deaths. Conclusion: Nab-paclitaxel and S-1 given every 2 weeks followed by S-1 as maintenance therapy showed promising activity against previously untreated unresectable or recurrent gastric cancers with excellent tolerated toxicities.