Phase II study of induction fixed-dose rate gemcitabine and bevacizumab followed by 30 gy radiotherapy as preoperative treatment for potentially resectable pancreatic adenocarcinoma

Background: Eighty percent of patients with resected pancreatic ductal carcinoma (PDC) experience treatment failure within 2 years. We hypothesized that preoperative fixed-dose rate (FDR) gemcitabine (GEM) combined with the angiogenesis inhibitor bevacizumab (BEV) and accelerated 30 Gy radiotherapy (RT) would improve outcomes among patients with potentially resectable PDC. Methods: This phase II trial tested induction FDR GEM (1,500 mg/m²) plus BEV (10 mg/kg IV) every 2 weeks for three cycles followed by accelerated RT (30 Gy in 10 fractions) plus BEV directed at gross tumor volume plus a 1-2 cm vascular margin. Subjects underwent laparoscopy and resection after day 85. Therapy was considered effective if the complete pathologic response rate exceeded 10 % and the margin-negative resection rate exceeded 80 %. Results: Fifty-nine subjects were enrolled; 29 had potential portal vein involvement. Two grade 4 (3.4 %) and 19 grade 3 toxicities (32.8 %) occurred. Four subjects manifested radiographic progression, and 10 had undetected carcinomatosis. Forty-three pancreatic resections (73 %) were performed, including 19 portal vein resections (44 %). Margin-negative outcomes were observed in 38 (88 %, 95 % confidence interval [CI] 75-96), with one complete pathologic response (2.3 %; 95 % CI 0.1-12). There were seven (6 grade 3; 1 grade 4) wound complications (13 %). Median overall survival for the entire cohort was 16.8 months (95 % CI 14.9-21.3) and 19.7 months (95 % CI 16.5-28.2) after resection. Conclusions: Induction therapy with FDR GEM and BEV, followed by accelerated BEV/RT to 30 Gy, was well tolerated. Although both effectiveness criteria were achieved, survival outcomes were equivalent to published regimens.