Gemcitabine with or without cisplatin in patients (pts) with advanced or metastatic biliary tract cancer (ABC): Results of a multicenter, randomized phase III trial (the UK ABC-02 trial)

Abstract

4503 Background: There is no established standard chemotherapy for pts with inoperable ABC. We previously reported an improvement in progression-free survival (PFS) in a randomised phase II trial of 86 pts (ABC-01) using gemcitabine/cisplatin (GemCis) vs. gemcitabine (Gem) (Valle ASCO-GI 2006, abstr. 98). This study was extended into ABC-02, a phase III trial, to recruit a further 314 pts with overall survival (OS) as the primary end-point. Methods: Consenting pts with histologically/cytologically-confirmed ABC, aged ≥18 years, ECOG performance status 0 - 2, and adequate haematological, hepatic and renal function were randomised to receive either Cis (25 mg/m2) followed by Gem (1000 mg/m2 D1, 8 q21d) for 8 cycles, or Gem alone (1000 mg/m2 on D1, 8, 15 q28d) for 6 cycles, stratified by extent of disease, site of primary tumour, ECOG score and centre. The trial had an 80% power to detect an OS hazard ratio of 0.73. Results: From May 2005 to October 2008, 324 pts were randomised to ABC- 02 from 34 UK centres. We report the pre-planned combined analysis of ABC-01 and ABC-02 based on 410 pts (GemCis=206/Gem=204). Patient characteristics: median age 64 yrs (range 23–85); male (47%); metastatic disease (75%), locally advanced (25%); gallbladder (36%), bile duct (59%), ampulla (5%); and ECOG 0–1 (87%), 2 (12%). With a median follow-up of 6.1 months and 263 deaths, the median OS was greater with GemCis than Gem, 11.7 vs. 8.2 months (log rank p=0.002), with hazard ratio 0.68 (95%-CI 0.53, 0.86). The median PFS was greater with GemCis than Gem, 8.5 vs. 6.5 months (log rank p=0.003), with hazard ratio 0.70 (95%-CI 0.56, 0.88).Toxicity was similar between the arms (by week 12, 57% had a grade 3/4 toxicity in each arm), though there was a slight excess of neutropenia using GemCis. Conclusions: This is the largest ever study in ABC and demonstrates a clear survival advantage for GemCis without added clinically significant toxicity, setting a new international standard of care. No significant financial relationships to disclose.