In a recent interview with Oncology Learning Network, Angela Lamarca, MD, PhD, MSc, Consultant Medical Oncologist, The Christie NHS Foundation Trust, Manchester, United Kingdom, discussed the research she and her colleagues recently conducted in the ABC-6 clinical trial, the results of which were presented at the 2019 ASCO Annual Meeting.

What existing data led you to evaluate active symptom control (ASC) alone or combined with oxaliplatin/5-FU chemo in patients with locally advanced/metastatic biliary tract cancers?

Despite phase 3 evidence being available for supporting the use of first-line cisplatin and gemcitabine for patients with advanced biliary tract cancer, no prospective trials were available to support the use of second-line chemotherapy. The ABC-06 study aimed to clarify the benefit of second-line oxaliplatin/5-FU after progression to cisplatin gemcitabine in terms of overall survival (OS).

Please briefly describe your study and its findings. Were any of the outcomes particularly surprising?

The ABC-06 clinical trial was a phase 3, randomized, open-label study recruiting patients with advanced biliary tract cancer with performance status 0-1, who had already progressed to first-line cisplatin-gemcitabine treatment.

Patients were randomized 1:1 to arm A, with active symptom control alone, or arm B, which combined active symptom control and palliative chemotherapy in the form of FOLFOX. Active symptom control consisted on four weekly appointments with a special focus on symptom control and early detection and treatment of biliary-related complications.

The study was powered for OS (primary end point).

The ABC-06 clinical trial met its primary end point (adjusted HR 0.69; 95% CI, 0.50-0.97; P = .031). Even though differences in median OS were modest (5.3 months vs 6.2 months) between study arms, differences in OS rate at 6-months (35.5% vs 50.6%) and 12-month (11.4% vs 25.9%) were clinically meaningful.

What are the possible real-world applications of these findings in clinical practice?

This is the first prospective phase III study, evaluating the benefit of chemotherapy after cisplatin-gemcitabine in patients with advanced biliary tract cancer.

The ABC-06 study showed that chemotherapy with FOLFOX combined with active symptom control, improved OS after progression to cisplatin-gemcitabine with a clinically meaningful reduction in the risk of death.

Based on this, FOLFOX chemotherapy should be considered as a new standard of care in the second-line setting for patients with advanced biliary tract cancer.

Will you and your co-investigators expand upon this research?

Quality of life, health economic evaluation, and translational research are ongoing.