A Randomised Phase 2 Trial of Intensive Induction Chemotherapy (CBOP/BEP) and Standard BEP in Poor-prognosis Germ Cell Tumours (MRC TE23, CRUK 05/014, ISRCTN 53643604)

Abstract

BackgroundStandard chemotherapy for poor-prognosis metastatic nonseminoma has remained bleomycin, etoposide, and cisplatin (BEP) for many years; more effective regimens are required. ObjectiveTo explore whether response rates with a new intensive chemotherapy regimen, CBOP/BEP (carboplatin, bleomycin, vincristine, cisplatin/BEP), versus those in concurrent patients treated with standard BEP justify a phase 3 trial. Design, setting, and participantsWe conducted a phase 2 open-label randomised trial in patients with germ cell tumours of any extracranial primary site and one or more International Germ Cell Cancer Collaborative Group poor-prognosis features. Patients were randomised between 2005 and 2009 at 16 UK centres. InterventionBEP (bleomycin 30 000 IU) was composed of four cycles over 12 wk. CBOP/BEP was composed of 2×CBOP, 2×BO, and 3×BEP (bleomycin 15 000 IU). Outcome measurements and statistical analysisPrimary end point was favourable response rate (FRR) comprising complete response or partial response and normal markers. Success required the lower two-sided 90% confidence limit to exclude FRRs <60%; 44 patients on CBOP/BEP gives 90% power to achieve this if the true FRR is ≥80%. Equal numbers were randomised to BEP to benchmark contemporary response rates. Results and limitationsA total of 89 patients were randomised (43 CBOP/BEP, 46 BEP); 40 and 41, respectively, completed treatment. CBOP/BEP toxicity, largely haematologic, was high (96% vs 63% on BEP had Common Terminology Criteria for Adverse Events v.3 grade ≥3). FRRs were 74% (90% confidence interval [CI], 61–85) with CBOP/BEP, 61% with BEP (90% CI, 48–73). After a median of 58-mo follow-up, 1-yr progression-free survival (PFS) was 65% and 43%, respectively (hazard ratio: 0.59; 95% CI, 0.33–1.06); 2-yr overall survival (OS) was 67% and 61%. Overall, 3 of 14 CBOP/BEP and 2 of 18 BEP deaths were attributed to toxicity, one after an overdose of bleomycin during CBOP/BEP. The trial was not powered to compare PFS. ConclusionsThe primary outcome was met, the CI for CBOP/BEP excluding FRRs <61%, but CBOP/BEP was more toxic. PFS and OS data are promising but require confirmation in an international phase 3 trial. Patient summaryIn this study we tested a new, more intensive way to deliver a combination of drugs often used to treat men with testicular cancer. We found that response rates were higher but that the CBOP/BEP regimen caused more short-term toxicity. Because most patients are diagnosed when their cancer is less advanced, it took twice as long to complete the trial as expected. Although we plan to carry out a larger trial, we will need international collaboration. Trial registrationISRCTN53643604; http://www.controlled-trials.com/ISRCTN53643604.