A single-arm phase II study to evaluate the efficacy and safety of docetaxel plus S-1 (DS) as second-line treatment in patients with AGC.

For patients with advanced gastric cancer, combination chemotherapy has been shown to improve the quality of life and overall survival (OS) compared with best supportive care alone. Docetaxel is an active agent for treating patients with gastric cancer. S-1, an oral 5-FU prodrug, is active against AGC as a single agent or in combination with cisplatin in phase III trials. Therefore, a single-arm phase II study was conducted to investigate the efficacy and safety of biweekly docetaxel and S-1 (DS) combination therapy as second-line treatment in patients with previously treated advanced gastric cancer.

Inclusion Criteria:

1. Age: 18-75 years old;
2. Histologically or cytologically confirmed unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma;
3. The patient has experienced disease progression during treatment or within 4 months after the last dose of first-line therapy without taxanes for metastatic disease.
4. Relapse within 6 months after adjuvant chemotherapy;
5. ECOG (Eastern Cooperative Oncology Group)performance status 0-2;
6. At least 1 measurable lesion should be present（RECIST1.1）
7. Available Organ function: Neutrophils>2g/L, Hemoglobin>9g/L, Blood platelet >100g/L; Alanine aminotransferase(ALT） and Aspartate aminotransferase(AST)<1.5 ULN(upper limit of normal); Total bilirubin(TBIL)<1.0 ULN; Cr <1.0ULN
8. Signed informed consent.
9. Life expectancy ≥3 months;

Exclusion Criteria:

1. Previous treatment with taxanes (not including intraperitoneal use of taxanes);
2. Known history of hypersensitivity to study drugs;
3. Active CNS metastases not controllable with radiotherapy or corticosteroids;
4. Pregnant or breast feeding women;
5. Severe co-morbid illness and/or active infections;
6. Active and uncontrollable bleeding from gastrointestinal tract
7. Patients receiving a concomitant treatment with drugs interacting with S-1 such as flucytosine, phenytoin, or allopurinol;
8. Other co-existing malignancies or malignancies diagnosed within the last 5 years(except cured cutaneum carcinoma or carcinoma in situs of cervix);
9. Known HIV infecton.