CHICAGO ― Adjuvant bevacizumab is well tolerated and improves the disease-free interval (DFI) for patients with melanoma at high risk of recurrence, indicate the interim results of the AVAST-M trial presented at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting.
Bevacizumab, a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF), has been shown to improve survival in several advanced solid tumors. Multiple adjuvant trials are underway, but previous trials of patients with colon cancer and triple-negative breast cancer did not meet primary endpoints.
Since VEGF is a relevant target in melanoma, Philippa Corrie, MD, Oncology Centre, Addenbrooke’s Hospital, Cambridge, United Kingdom, and colleagues aimed to evaluate the role of bevacizumab in patients with resected melanoma at high risk of recurrence.
Between July 2007 and March 2012, a total of 1,343 patients with resected AJCC stage IIB, IIC, or III(A-C) cutaneous melanoma were recruited for a randomized, multicenter, phase III trial (AVAST-M). Participants were randomly assigned within 12 weeks of surgery and had clear computed tomography scans within 8 weeks of trial entry. More than half (56%) were male with a median age of 56 years (range 18-88 years). Ulceration status of the primary melanoma was as follows: 38%, present; 45%, absent; and 17% unknown.
Half of participants (n=671) were assigned to receive bevacizumab 7.5mg/kg intravenously every 3 weeks for 1 year (maximum of 17 infusions over 1 year, or until disease progression) compared to standard observation (n=672). Follow-up was continued until 10 years or death. The primary endpoint was overall survival (OS); secondary endpoints included DFI, distant-metastasis free interval, safety and toxicity, and quality of life.
The median duration of treatment in 671 treated patients was 51 weeks (dose intensity, 86%), and 54% of patients successfully completed the planned treatment. Reasons for discontinuing the study included disease recurrence (38%), toxicity (33%), patient choice (10%), death (1%), or other (18%).
Grade 3/4 adverse events were experienced in 101 (15%) patients treated with bevacizumab and 36 (5%) observation patients. At the time of the interim analysis, 286 (21%) patients had died. Median follow-up for survival was 25 months.
At trial end, the DFI was 263 (39%) with bevacizumab versus 298 (44%) in the standard observation group (hazard ratio [HR], 0.83; 95% CI: 0.70-0.98; P=0.03). The 1-year survival rate was slightly higher with bevacizumab: 95% versus 94% with standard observation (HR, 0.97; 95% CI: 0.78-1.22; P=0.76).
“Adjuvant bevacizumab did improve [the] DFI. Longer follow-up is required to determine an impact on the primary endpoint of 5-year OS,” the researchers concluded.
Biomarkers to predict patients who may benefit from this therapy are being explored.