Phase III Trial Evaluating Letrozole As First-Line Endocrine Therapy With or Without Bevacizumab for the Treatment of Postmenopausal Women With Hormone Receptor–Positive Advanced-Stage Breast Cancer: CALGB 40503 (Alliance)
Year: 2016
Type: article
Study designs: Randomized Controlled Trial, Clinical Trial
Abstract: PURPOSE: To investigate whether anti-vascular endothelial growth factor therapy with bevacizumab prolongs progression-free survival (PFS) when added to first-line letrozole as treatment of hormone receptor-positive metastatic breast cancer (MBC). PATIENTS AND METHODS: Women with hormone receptor-positive MBC were randomly assigned 1:1 in a multicenter, open-label, phase III trial of letrozole (2.5 mg orally per day) with or without bevacizumab (15 mg/kg intravenously once every 3 weeks) within strata defined by measurable disease and disease-free interval. This trial had 90% power to detect a 50% improvement in median PFS from 6 to 9 months. Using a one-sided α = .025, a target sample size of 352 patients was planned. RESULTS: From May 2008 to November 2011, 350 women were recruited; 343 received treatment and were observed for efficacy and safety. Median age was 58 years (range, 25 to 87 years). Sixty-two percent had measurable disease, and 45% had de novo MBC. At a median follow-up of 39 months, the addition of bevacizumab resulted in a significant reduction in the hazard of progression (hazard ratio, 0.75; 95% CI, 0.59 to 0.96; P = .016) and a prolongation in median PFS from 15.6 months with letrozole to 20.2 months with letrozole plus bevacizumab. There was no significant difference in overall survival (hazard ratio, 0.87; 95% CI, 0.65 to 1.18; P = .188), with median overall survival of 43.9 months with letrozole versus 47.2 months with letrozole plus bevacizumab. The largest increases in incidence of grade 3 to 4 treatment-related toxicities with the addition of bevacizumab were hypertension (24% v 2%) and proteinuria (11% v 0%). CONCLUSION: The addition of bevacizumab to letrozole improved PFS in hormone receptor-positive MBC, but this benefit was associated with a markedly increased risk of grade 3 to 4 toxicities. Research on predictive markers will be required to clarify the role of bevacizumab in this setting.
Source: Journal of Clinical Oncology
Language: English
Subfield: Cancer Research
Domain: Life Sciences
Open Access status: green
Awards: G1000381934, Alliance Statistics and Data Management Center, G1814228702, ECOG-ACRIN Network Group Operations Center, G1938688226, Network Lead Academic Participating Site: Memorial Sloan-Kettering Cancer Center, G2453551107, SWOG Network Group Operations Center of the NCTN, G4040562365, G4185274752, G4194574630, Building upon a tradition of excellence. The NCTN at Indiana University, Cancer and Leukemia Group B, NCTN Lead Academic Participating Sites Application, Alliance for Clinical Trials in Oncology Operations Center, Cancer Center Support Grant
OpenAlex ID: W2346624277