Phase 2 study of erlotinib combined with adjuvant chemoradiation and chemotherapy in patients with resectable pancreatic cancer

Purpose: Long-term survival rates for patients with resected pancreatic ductal adenocarcinoma (PDAC) have stagnated at 20% for more than a decade, demonstrating the need to develop novel adjuvant therapies. Gemcitabine- erlotinib therapy has demonstrated a survival benefit for patients with metastatic PDAC. Here we report the first phase 2 study of erlotinib in combination with adjuvant chemoradiation and chemotherapy for resected PDAC. Methods and Materials: Forty-eight patients with resected PDAC received adjuvant erlotinib (100 mg daily) and capecitabine (800 mg/m² twice daily Monday-Friday) concurrently with intensity modulated radiation therapy (IMRT), 50.4 Gy over 28 fractions followed by 4 cycles of gemcitabine (1000 mg/m ² on days 1, 8, and 15 every 28 days) and erlotinib (100 mg daily). The primary endpoint was recurrence-free survival (RFS). Results: The median follow-up time was 18.2 months (interquartile range, 13.8-27.1). Lymph nodes were positive in 85% of patients, and margins were positive in 17%. The median RFS was 15.6 months (95% confidence interval [CI], 13.4-17.9), and the median overall survival (OS) was 24.4 months (95% CI, 18.9-29.7). Multivariate analysis with adjustment for known prognostic factors showed that tumor diameter >3 cm was predictive for inferior RFS (hazard ratio, 4.01; P=.001) and OS (HR, 4.98; P=.02), and the development of dermatitis was associated with improved RFS (HR, 0.27; P=.009). During CRT and post-CRT chemotherapy, the rates of grade 3/4 toxicity were 31%/2% and 35%/8%, respectively. Conclusion: Erlotinib can be safely administered with adjuvant IMRT-based CRT and chemotherapy. The efficacy of this regimen appears comparable to that of existing adjuvant regimens. Radiation Therapy Oncology Group 0848 will ultimately determine whether erlotinib produces a survival benefit in patients with resected pancreatic cancer.