Purpose: On the basis of evidence that resistance to vascular endothelial growth factor (VEGF) receptor inhibition is caused by hypoxia-driven residual VEGF and other proangiogenic factors, combinations of agents from these classes were hypothesized to improve treatment outcomes relative to single-agent VEGF pathway blockade.
Patients and methods: A total of 361 patients with metastatic clear cell renal cell carcinoma were randomly assigned equally to arm A (bevacizumab monotherapy 10 mg/kg intravenously [IV] every 2 weeks), B (bevacizumab 10 mg/kg IV every 2 weeks and temsirolimus 25 mg IV every week), C (bevacizumab 5 mg/kg IV every 2 weeks and sorafenib 200 mg orally twice daily on days 1 to 5, 8 to 12, 15 to 19, and 22 to 26), or D (sorafenib 200 mg twice daily and temsirolimus 25 mg IV weekly). Progression-free survival was the primary end point.
Results: Among 331 eligible treated patients, median PFS was 7.5 months for bevacizumab alone (90% CI, 5.8 to 10.8 months), 7.6 months for bevacizumab plus temsirolimus (90% CI, 6.7 to 9.2 months), 9.2 months for bevacizumab plus sorafenib (90% CI, 7.5 to 11.4 months), and 7.4 months for sorafenib plus temsirolimus (90% CI, 5.6 to 7.9 months). Hazard ratios from stratified Cox proportional hazards models were 1.01, 0.89, and 1.07 (with respective P values of .95, .49, and .68) for the three combinations, respectively, compared with bevacizumab alone. Adverse events did not differ significantly among treatment arms.
Conclusion: The activity of sorafenib, temsirolimus, and bevacizumab administered in doublet combinations did not significantly improve median progression-free survival in comparison with bevacizumab monotherapy.
Trial registration: ClinicalTrials.gov NCT00378703.
© 2015 by American Society of Clinical Oncology.