A Randomized, Multicenter, Open-label, Phase 3 Study to Compare the Efficacy and Safety of GEMOX(Gemcitabine/Oxaliplatin) vs XELOX(Xeloda/Oxaliplatin) in Advanced Biliary Tract Carcinoma

In patients with advanced BTC(biliary tract cancer), either gemcitabine-based, 5-FU-based chemotherapy or clinical trial is recommended as first-line treatment. According to ABC-02 trial, as compared with gemcitabine alone, cisplatin plus gemcitabine was associated with a significant survival advantage without the addition of substantial toxicity. Cisplatin plus gemcitabine is an appropriate option for the treatment of patients with advanced biliary cancer. (ClinicalTrials.gov number, NCT00262769.) Recent metaanalysis [7], analyzed 104 phase II and III trials comprising 2810 BTC patients and found that gemcitabine combined with platinum compounds such as cisplatin or oxaliplatin had superior response rate and survival when compared with gemcitabine alone. The metaanalysis concluded the combination of gemcitabine and cisplatin or oxaliplatin to be the reference arm for future clinical trials.

Meanwhile, oxaliplatin (l-OHP), an alkylating diaminocyclohexane platinum derivate, has been noted to display a marked cytotoxic synergism in combination with fluoropyrimidines against a variety of solid human tumour cells [11]. Based on these information, Nehls et al. [12] conducted a prospective phase II study of oxaliplatin plus 5-FU/folinic acid in biliary system adenocarcinomas, and the disease control rate (responses and stable disease (SD)) was 56%, and the median OS was 9.5 months. To improve efficacy and to offer a more convenient treatment option for patients by reducing clinical visits and avoiding indwelling devices, they prospectively investigated the activity and toxicity profile of three-weekly intravenous oxaliplatin plus oral capecitabine (XELOX), and concluded that the XELOX regimen was a well-tolerated and active treatment option for advanced BTC [13].

Given a lack of prospective, direct, comparison between XELOX and GEMOX regimens in advanced BTC, we propose a randomized phase III trial of GEMOX (gemcitabine/oxaliplatin) vs XELOX (capecitabine/oxaliplatin) in metastatic or unresectable BTC patients.

With the assumption of a median 6-month PFS rate of 50% in the GEMOX arm and 35% in the XELOX arm (non-inferiority margin, 15%), a total of 103 patients were required under a two-sided 5% significance level and 80% power, with an accrual of 59 months and a follow-up of 6 months after the last patient registry, to show the non-inferiority of XELOX to GEMOX. An exponential distribution of time to progression was assumed. Allowing a dropout rate of 10%, we aimed to enroll 230 patients. An interim analysis was not planned.