Apatinib for patients with metastatic biliary tract carcinoma refractory to standard chemotherapy: results from an investigator-initiated, open-label, single-arm, exploratory phase II study

BACKGROUND: There is no standard therapy for metastatic biliary tract carcinoma (BTC) refractory to first-line chemotherapy. Apatinib, a VEGFR2 tyrosine kynase inhibitor, showed an activity against BTC xenografts in preclinical models. We conducted an exploratory study to evaluate the efficacy and safety of apatinib in patients with metastatic BTC. METHODS: This is a single-arm phase II study [ClinicalTrials.gov identifier: NCT03427242]. Eligible patients were aged 18 years or older; histologically confirmed metastatic BTC; refractory or intolerance to at least one chemotherapeutic regimen; no prior use of anti-angiogenic targeted drugs; Eastern Cooperative Oncology Group performance status of 0–2. Patients received oral apatinib 500 mg each day continuously until unacceptable toxicity or tumor progression. The primary endpoint was progress free survival (PFS). The secondary endpoint was overall survival (OS), objective response rate (ORR) and treatment safety. RESULTS: A total of 22 patients were recruited. All of them received apatinib medication. The median age was 63 (44–75) years old. Twenty patients received efficacy evaluation after treatment. The objective response rate (ORR) and disease control rate (DCR) were 15.0% and 60.0%, respectively. The median PFS was 2.73 months [95% confidence interval (CI): 1.74–3.72 months], with 6 months PFS rate of 27.3% (95% CI: 8.7–45.9%). The median OS was 4.81 months (95% CI: 3.16–10.9 months), with 12 months OS rate of 36.4% (95% CI: 16.2–56.6%). Nine out of 22 patients (40.9%) had grade 3/4 adverse events. The most common grade 3/4 adverse events were hand-foot skin syndrome [three (13.6%) patients] and hypertension [two (9.1%) patients]. No treatment-related death occurred. CONCLUSIONS: For patients with metastatic BTC, apatinib showed an anti-tumor activity with acceptable safety, which deserves the further clinical trial. This trial was prospectively registered on ClinicalTrials.gov [NCT03427242]. Date of first patient enrollment: 26 January 2018. Date of registration (date of first posted): 9 February 2018.