A phase II study of bevacizumab plus erlotinib for gemcitabine-refractory metastatic pancreatic cancer.

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.