Gemcitabine in Combination With Pemetrexed Long Term Infusion in the Treatment of Pretreated Metastatic Colorectal Cancer Patients

Study Design:
Multicenter, non randomized, open label phase II study designed to evaluate the efficacy and safety of Gemcitabine/Pemetrexed combination.
Enrollment period: 18 months. Treatment period: maximum for 24 weeks for each patient (12 cycles lasting 2 weeks).
Total duration of the study: 24 months.
Number of Subjects:
Approximately 38 subjects will be enrolled on study:
- First stage:12 patients enrolled
If 1 or 0 responses were observed, the trial had to be terminated:
- Second stage: an additional of 23 patients were to be enrolled. If 5 or less responses were observed in 35 patients, the combination would not be considered worthy of further study, while if 6 or more responses were observed, the combination would be considered sufficiently active to warrant further testing. Taking into account an invalidity rate of 5%, 38 patients will be needed for this step.

研究设计：
本研究为多中心、非随机、开放标签的II期临床试验，旨在评估吉西他滨（Gemcitabine）联合培美曲塞（Pemetrexed）方案的疗效与安全性。
入组周期：18个月。
治疗周期：每位患者最长治疗时长为24周（共12个周期，每个周期时长为2周）。
研究总时长：24个月。

受试者规模：
本研究计划入组约38名受试者：
- 第一阶段：入组12名患者。若该阶段内观察到的抗肿瘤应答数为0或1，则终止本试验。
- 第二阶段：额外入组23名患者。若35名可评估患者中的抗肿瘤应答数≤5，则该联合方案不具备进一步研究的价值；若应答数≥6，则该联合方案显示出足够的抗肿瘤活性，值得开展后续试验。考虑到5%的无效病例率，本阶段共需入组38名患者。