Combination of gemcitabine and cetuximab in patients with advanced cholangiocarcinoma: A phase II study of the Belgian Group of Digestive Oncology.

Abstract

245 Background: Cholangiocarcinomas (CCK) are uncommon tumors with an increasing incidence and a poor prognosis. Epidermal growth factor receptor (EGFR) expression and activation in CCK have been demonstrated. Methods: We conducted a multicenter phase II trial combining cetuximab (Ctx), an anti-EGFR chimerized IgG1 monoclonal antibody, to gemcitabine (Gem). Patients with either locally advanced (LA) or metastatic (M) CCK (excluding gallbladder) were included; no prior systemic therapy was allowed. Ctx was administrated at the initial dose of 400 mg/m2 and further injections at 250 mg/m2 every 7 days, and Gem was administrated at 1000 mg/m2 on days 1, 8, and 15 every 4 weeks. The primary endpoint was the progression-free survival (PFS) rate at 6 months. A Simon 2-stage design was used. We hypothesized that Gem/Ctx would improve 6 month-PFS rate from 20% to 40%. We needed 3 patients with PFS ≥ 6 months from the first 13 to further include a total of 43 patients. Results: Forty-four patients with advanced CCK (41% LA/59%M) were enrolled from 09/2008 to 01/2010. Median age was 61.5 years (range 40-86) and baseline ECOG PS was 0 for 68% and 1 for 32% of the patients. Forty-three percent of the patients had prior surgery. Forty-six percent of the patients were free from progression at 6 months. Median PFS was 5.8 months (95% CI, 4.4-7.4 m) and median overall survival was 11.6 months (95% CI, 8.7-14.6 m). Nine patients (20.9%) had partial response with a median duration of 5 months (range 2-10 m). Disease control rate (PR + SD > 8 weeks) was 81.4%. The most common grades 3/4 related-toxicities were haematological abnormalities (47.7%), skin rash (13.6%) and fatigue (11.3%). Due to toxicity, 6 patients discontinued study treatment; 14 and 3 patients had a Gem and Ctx dose reduction respectively. Among the nine responders, 8 experienced a skin rash of at least grade 2, suggesting a relationship between skin toxicity and efficacy. Conclusions: Our study met its endpoint, i.e., a PFS rate of 46% at 6 months, suggesting that Gem-Ctx combination had promising activity with a manageable toxicity profile in advanced CCK. Adding Ctx to the new standard of care Gem-cisplatin deserves further investigations in CCK. [Table: see text]