Panitumumab in Combination with Gemcitabine and Oxaliplatin Does Not Prolong Survival in Wild-type KRAS Advanced Biliary Tract Cancer: A Randomized Phase 2 Trial (Vecti-BIL Study)

Background: Biliary tract cancer (BTC) is a rare and lethal disease with few therapeutic options. Preclinical data suggest that the epidermal growth factor receptor (EGFR) pathway could be involved in its progression.

Methods: This open-label, randomized phase 2 trial recruited chemotherapy-naive patients with advanced BTC displaying a wild-type (WT) KRAS status. Patients were randomized to gemcitabine (1000 mg/m(2) ) and oxaliplatin (100 mg/m(2) ) with (arm A) or without (arm B) panitumumab (6 mg/kg) for up to 12 cycles. The primary endpoint was progression-free survival (PFS) analyzed in an intention-to-treat fashion.

Results: Eighty-nine patients (45 in arm A and 44 in arm B) were enrolled between June 2010 and September 2013. After a median follow-up of 10.1 months, the median PFS was 5.3 months (95% confidence interval, 3.3-7.2 months) in arm A and 4.4 months (95% confidence interval, 2.6-6.2 months) in arm B (P = .27). No survival differences were observed: the median overall survival was 9.9 months in arm A and 10.2 months in arm B (P = .42). In a subgroup analysis, no differences in PFS according to the site of the primary tumor were observed; patients with intrahepatic cholangiocarcinoma treated with panitumumab may have had a survival benefit in comparison with the control group (15.1 vs 11.8 months, P = .13). As for safety, skin toxicity was the main adverse event in arm A (80% of the patients). A higher incidence of diarrhea (55.5% vs 31.8%), mucositis (22.2% vs 13.6%), and constipation (24.4% vs 15.9%) was seen in arm A.

Conclusions: These results confirm the marginal role of anti-EGFR therapy even for WT KRAS-selected BTC.