A phase II study of bevacizumab plus erlotinib for gemcitabine-refractory metastatic pancreatic cancer
No standard of care exists for patients with metastatic pancreatic cancer following progression on first-line chemotherapy. Based on potential for additive or synergistic activity by concurrent inhibition of VEGF and EGFR, we conducted a phase II study evaluating the combination of bevacizumab plus erlotinib in this patient population. Patients with metastatic pancreatic adenocarcinoma, ECOG performance status 0–1, and previous exposure to 1–3 systemic therapies (at least one gemcitabine-based) were eligible. Treatment consisted of bevacizumab 15 mg/kg every 21 days plus erlotinib 150 mg daily. Thirty-six patients were enrolled, including eight who had previously received VEGF-targeted therapy and nine prior erlotinib. Median number of treatment cycles was 2 (range, 1–7). Common toxicities included rash (72%), diarrhea (25%), venous thromboembolic events (15%), and hypertension (11%). One patient demonstrated partial response and seven others stable disease for >2 cycles. CA19-9 decline ≥25% was observed in 4/26 patients with baseline levels >2x ULN. Estimated median time to progression was 40 days (95% CI, 35–41 days) and median survival 102 days (95% CI, 74–117 days), with a 6-month survival rate of 22%. Baseline concentration of circulating endothelial cells (CD45−/CD34+/CD31+) was inversely associated with overall survival. The combination of bevacizumab and erlotinib is safe but relatively ineffective in patients with gemcitabine-refractory metastatic pancreatic cancer. Future studies should focus on refining subsets of patients in this challenging population likely to benefit from treatment beyond first-line.