Phase I/II Trial of Perioperative Avelumab in Combination With Chemoradiation in the Treatment of Stage II/III Resectable Esophageal and Gastroesophageal Junction Cancer.

BACKGROUND AND OBJECTIVES

Standard treatment of patients with stage II/III esophageal or gastroesophageal junction (E/GEJ) cancer involves neoadjuvant chemoradiation (nCRT), resection, and immunotherapy. Our trial evaluated the addition of perioperative avelumab to standard treatments.

METHODS

Patients with resectable E/GEJ cancers received avelumab with nCRT and adjuvant avelumab after resection. Primary endpoints for phase I and II portions were safety and pathologic complete response (pCR) rate, respectively. Secondary endpoints included recurrence-free survival (RFS), surgical complication prevalence, and R0 resection rate.

RESULTS

Twenty-two patients enrolled in the study. Median follow-up during data cutoff was 23.9 months. There were no dose-limiting toxicities during the run-in phase. Nineteen patients (86.4%) underwent resection with R0 resection rate of 78.9% and with pCR rate of 26%. Most common treatment-related adverse events (TRAE) were cytopenias from chemoradiation. Aside from one grade ≥ 3 avelumab-related hypersensitivity, no grade ≥ 3 avelumab TRAEs were seen. Median RFS was not reached, and 1-year RFS and overall survival were 71% and 81%, respectively. The study was terminated before full planned accrual due to standard practice change based on the CheckMate 577 trial.

CONCLUSIONS

The addition of perioperative avelumab to nCRT was tolerable and demonstrated promising outcomes.