Atezolizumab combined with bevacizumab shows “encouraging efficacy” versus sunitinib as first-line treatment for locally advanced or metastatic renal cell carcinoma (RCC) expressing programmed death-ligand 1 (PD-L1), researchers reported in a poster presentation at the 2017 Genitourinary Cancers Symposium in Orlando, Florida.
Atezolizumab (Tecentriq) is a monoclonal antibody that binds with PD-L1 expressed on tumor cells and tumor-infiltrating cells. By inhibiting PD-L1, the drug may enable activation of T cells. Bevacizumab (Avastin) is a monoclonal antibody that inhibits tumor angiogenesis by binding to vascular endothelial growth factor. According to researchers, atezolizumab and bevacizumab may reactivate the cancer immunity cycle.
In a multicenter, randomized phase 2 study (IMmotion 150), patients in the PD-L1 subgroup who received the combination had significantly longer median progression-free survival (PFS) compared with those who received sunitinib alone (14.7 vs 7.8 months). Atezolizumab plus bevacizumab was associated with a significant 36% lower risk of disease progression compared with sunitinib. The study found no PFS advantage in the overall study population.
For the study, David McDermott, MD, of Beth Israel Deaconess Medical Center in Boston, and colleagues randomly assigned 305 treatment-naïve patients with locally advanced or metastatic RCC received atezolizumab plus bevacizumab (101 patients), atezolizumab alone (103 patients), and sunitinib alone (101 patients). The atezolizumab/bevacizumab group received atezolizumab 1200 mg intravenously (IV) and bevacizumab 15 mg/kg IV every 3 weeks until disease progression or lack of clinical benefit was observed. Patients in the atezolizumab arm received 1200 mg of the drug IV every 3 weeks until disease progression or lack of clinical benefit was observed. The sunitinib group received 50 mg of drug orally 4 weeks followed by 2 weeks off the drug until disease progression. The study population had a median follow-up of 20.7 months.
The safety of atezolizumab and bevacizumab was consistent with previous data for each drug alone.
The clinical benefit of atezolizumab plus bevacizumab compared with sunitinib will be evaluated in the ongoing Phase 3 study (IMmotion151; NCT02420821).
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McDermott D, Atkins M, Motzer R, et al. Phase II study of atezolixumab with or without bevacizumab vs sunitinib in untreated metastatic renal cell carcinoma patients. Data presented in poster format at the 2017 Genitourinary Cancers Symposium in Orlando, Florida. Poster Session C, Board B14. Abstract 431.