Phase II study of bevacizumab and preoperative chemoradiation for esophageal adenocarcinoma

A standard-of-care for locally advanced esophageal and gastroesophageal junction (GEJ) adenocarcinoma is pre-operative chemoradiation. Elevated levels of vascular endothelial growth factor (VEGF) have been associated with worse outcomes following chemoradiation and anti-VEGF therapies can potentiate radiation efficacy.

In this single-arm phase II study, we added bevacizumab to induction chemotherapy and concurrent chemoradiation with cisplatin/irinotecan for locally advanced esophageal and GEJ adenocarcinomas.

Thirty-three patients were enrolled, with all evaluable. All tumors involved the GEJ and 67% were node-positive by endoscopic ultrasound (EUS) and imaging. Twenty-eight patients completed chemoradiation and 26 patients underwent surgery (25 R0 resections). Toxicities were not clearly increased. The pathologic complete response (pCR) rate was 15%. Median progression-free survival (PFS) and overall survival (OS) were 15.1 and 30.5 months respectively. Higher baseline VEGF-A levels were associated with a trend toward improved OS (not reached vs. 21.0 months, P=0.11). Response on positron emission tomography (PET) scan after induction chemotherapy was predictive of PFS and showed trends toward improved OS and pCR rate.

The addition of bevacizumab to chemoradiation was not associated with clear worsening of toxicities but also led to no improvement in outcomes, when compared to a prior phase II study of 55 patients. Higher baseline VEGF-A levels correlated with a trend toward improved survival and might be used to stratify or select patients for future studies incorporating this or similar agents. PET scan to assess response following induction chemotherapy and change chemotherapy in non-responders during chemoradiation is the subject of a fully-accrued national trial (NCT01333033).