Randomised, phase II study of selumetinib, an oral inhibitor of MEK, in combination with cisplatin and gemcitabine chemotherapy for patients with advanced biliary tract cancer

Abstract

Introduction: Cisplatin and gemcitabine (CisGem) are standard chemotherapy for advanced biliary tract cancer (BTC). The MEK inhibitor selumetinib showed synergy with gemcitabine when administered sequentially in BTC. This randomised Phase 2 trial aimed to assess the efficacy of sequential or continuous selumetinib with CisGem. Methods: Patients with advanced BTC received CisGem; arm A included selumetinib every day, arm B: selumetinib, days 1-5, 8-19 each cycle. Arm C received CisGem alone. Selumetinib was dosed at 75 mg BID but amended to 50 mg BID due to toxicity. Results: In all, 51 participants were evaluable for response. No significant difference was seen in mean change in tumour size at 10 weeks between arms A and C (-7.8% vs -12.8%, P = 0.54) or arms B and C (-15% vs -12.8%, P = 0.78). There was no difference in median progression-free survival (6.0, 7.0, 6.3 months, P > 0.95) or overall survival (11.7, 11.7, 12.8 months, P = 0.70) for arms A, B and C, respectively. More participants experienced grade 3-4 toxicities in selumetinib-containing arms. More participants in arm A required chemotherapy dose reductions (P = 0.01) with lower chemotherapy dose intensity during the first 10 weeks. Conclusion: Adding sequential or continuous selumetinib to CisGem failed to improve efficacy and increased toxicity in patients with advanced BTC.