This is a single-arm clinical trial.The purpose of this study is to evaluate the efficacy and safety of Raltitrexed and Paclitaxel as second-line chemotherapy for patients with unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma .The primary endpoint of this study is objective response rate.The secondary endpoint of this study is safety,progression-free survival and overall survival.

Raltitrexed is an antifolate thymidylate synthase inhibitor that has shown efficacy and good safety profile in the treatment of colorectal cancer. To our knowledge, there has been no study published with the Raltitrexed and Paclitaxel regimen as second-line chemotherapy for patients with unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.The aim of our study was to evaluate the efficacy, safety and survival of this regimen in patients with unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.

Inclusion Criteria:

• Histologically or cytologically confirmed unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma;
• Patients failed first-line chemotherapy containing fluoropyrimidines and platinums;
• ECOG (Eastern Cooperative Oncology Group)performance status 0-1;
• At least 1 measurable lesion should be present（RECIST1.1）
• 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
• Signed informed consent.
• Life expectancy ≥3 months;

Exclusion Criteria:

• Previous treatment with Raltitrexed or Paclitaxel;
• Known history of allergic reaction to Raltitrexed or Paclitaxel;
• Known brain metastases;
• Pregnant or breast feeding women;
• Severe diarrhea,intestinal obstruction;
• other co-existing malignancies or malignancies diagnosed within the last 5 years(except cured cutaneum carcinoma or carcinoma in situs of cervix);
• Previous myocardial infarction, unstable angina, stroke ,or uncontrollable Arrhythmia;
• Kown HIV infecton.