Randomized phase II trial of cixutumumab alone or with cetuximab for refractory recurrent/metastatic head and neck squamous cell carcinoma. (July 2018) - Ferrarotto, Renata
Highlights: Cixutumumab with or without cetuximab had limited activity in metastatic HNSCC patients. High level of nuclear p-EGFR in tumor was associated with worse PFS in the CIX arm. High expression of IGF-1 in tumor correlated with better PFS in the combined arm. Serum IGF1/2 levels were not modulated on therapy; thus, IGF1-R may not have been inhibited. Abstract: Objectives: Cixutumumab (CIX) and cetuximab (CET) monoclonal antibodies block ligand-binding to insulin-like growth factor-1 receptor (IGF-1R) and epidermal growth factor receptor (EGFR) respectively. The objective of this study was to assess the efficacy of CIX alone or combined with CET in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) patients. Methods: In this open-label phase II trial, 91 R/M HNSCC patients who progressed within 90 days of platinum-based chemotherapy, were randomized to CIX 10 mg/kg alone or with CET 500 mg/m 2 every 2 weeks. Patients were stratified by prior CET use. The primary endpoint was median progression-free survival (PFS). Exploratory biomarker assessments included relevant markers on archival tumor and serial cytokine/angiogenic-factor profiles in blood. Results: Forty-seven patients were treated with CIX monotherapy and 44 with combination. The median PFS was 1.9 and 2.0 months and clinical benefit rate (complete or partial responses and stable disease) was 5.9% and 15.3%, respectively. There was no exacerbation of CET toxicity by concurrent CIX exposure. Higher tumor expression of IGF-1 was associated with improved PFS in the CIX + CET arm while increased p-EGFR expression correlated with shorter PFS in patients receiving single agent CIX. Higher serum baseline levels of IGF-1 and IGFBP-3 correlated with improved PFS and overall survival (OS) in the CIX arm. Neither regimen resulted in improved PFS or OS compared to historical data with CET alone. Conclusion: The results of this study do not support the use of cixutumumab alone or with cetuximab in unselected patients with R/M HNSCC.