Pemetrexed and Erlotinib as a Salvage Treatment in Patients With Metastatic Biliary Tract Cancer Who Failed Gemcitabine-containing Chemotherapy: A Phase II Single-arm Prospective Study.

BACKGROUND/AIM: No standard treatment is currently recommended for advanced biliary tract cancer (BTC) after first-line therapy with gemcitabine plus cisplatin. We aimed to evaluate the efficacy and safety of a pemetrexed and erlotinib combination in patients with BTC previously treated with gemcitabine.

PATIENTS AND METHODS

This phase II, open-label, single-arm study enrolled patients with BTC who had previously failed gemcitabine-based first-line chemotherapy. Patients were treated with pemetrexed as a 500 mg/m intravenous infusion on day 1 for three weeks and erlotinib 100 mg daily until disease progression or unacceptable toxicity. The primary endpoint was the overall response rate (ORR).

RESULTS

The study enrolled 20 patients with BTC, including 12 (60%) with intrahepatic cholangiocarcinoma (IHCC), 3 (15%) with extrahepatic cholangiocarcinoma (EHCC), and 5 (25%) with gallbladder cancer (GBC). The ORR was 5%, and the disease control rate (DCR) was 55%. As of the cutoff point of March 31, 2023, the median progression-free survival (PFS) was 2.3 months [95% confidence interval (CI)=0.00-4.74] and the median overall survival (OS) was 5.6 months (95%CI=2.28-8.87). Patients with EHCC showed longer PFS and OS compared to patients with IHCC or GBC, but the differences were not significant. A baseline CEA greater than the upper normal limit was the only significant prognostic factor for a worse OS rate. The only treatment-related adverse event (TRAE) with severity grade ≥3 was anemia (5%).

CONCLUSION

Salvage chemotherapy with pemetrexed plus erlotinib was well-tolerated and showed marginal clinical activity in BTC patients after failure to gemcitabine-based chemotherapy.