Adjuvant bevacizumab as treatment for melanoma patients at high risk of recurrence: Preplanned interim results for the AVAST-M trial.

Background: Bevacizumab (Bev) is a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF) shown to improve survival in several advanced solid tumors. Multiple adjuvant trials are underway, but trials that have reported in colon and triple-negative breast cancer did not meet their primary end points. Since VEGF is a relevant target in melanoma, AVAST-M aimed to evaluate the role of Bev in patients (pts) with resected melanoma at high risk of recurrence. Methods: AVAST-M is a randomized phase III trial evaluating single agent Bev (7.5mg/kg IV 3 weekly for 1 year) as adjuvant therapy following resection of AJCC stage IIB, IIC, and III cutaneous melanoma compared to standard observation (Obs). 1,320 pts were required to detect 8% differences in 5-year overall survival (OS) rate from 40% to 48%; 85% power, 5% alpha level. Primary endpoint is OS; secondary endpoints are disease free interval (DFI), distant-metastasis free interval (DMFI), safety, and quality of life (QoL). An associated translational study is ongoing. Results of the first pre-planned interim analysis (agreed by the IDSMC) are reported here. Results: Between July 2007 and March 2012, 1,343 pts were recruited. 56% were male; median age 56 years (range 18-88 years), 16% were stage IIB, 11% IIC, 15% IIIA, 36% IIIB, 20% IIIC, and 2% unknown stage. Ulceration status of the primary melanoma was: 38% present, 45% absent, 17% unknown. At the time of the interim analysis, 286 (21%) patients had died. Median follow-up for survival was 25 months. Median duration of Bev treatment in 671 treated pts was 51 weeks (dose intensity 86%). Main outcomes are shown in the table. Grade 3/4 adverse events were experienced in 101 (15%) Bev pts and 36 (5%) Obs pts. Conclusions: Interim analysis of this large, multicenter trial of melanoma patients at high risk of recurrence has shown that adjuvant Bev monotherapy is well tolerated and improved DFI. Longer follow-up is required to determine an impact on the primary endpoint of 5-year OS.