Adjuvant bevacizumab in patients with melanoma at high risk of recurrence (AVAST-M): preplanned interim results from a multicentre, open-label, randomised controlled phase 3 study.

BACKGROUND: Bevacizumab, a monoclonal antibody that targets VEGF, has shown restricted activity in patients with advanced melanoma. We aimed to assess the role of bevacizumab as adjuvant treatment for patients with resected melanoma at high risk of recurrence. We report results from the preplanned interim analysis. METHODS: We did a multicentre, open-label, randomised controlled phase 3 trial at 48 centres in the UK between July 18, 2007, and March 29, 2012. Patients aged 16 years or older with American Joint Committee on Cancer stage (AJCC) stage IIB, IIC, and III cutaneous melanoma were randomly allocated (1:1), via a central, computer-based minimisation procedure, to receive intravenous bevacizumab 7.5 mg/kg, every 3 weeks for 1 year, or to observation. Randomisation was stratified by Breslow thickness of the primary tumour, N stage according to AJCC staging criteria, ulceration of the primary tumour, and patient sex. The primary endpoint was overall survival; secondary endpoints included disease-free interval, distant-metastases interval and quality of life. Analysis was by intention-to-treat. This trial is registered as an International Standardised Randomised Controlled Trial, number ISRCTN81261306. FINDINGS: 1343 patients were randomised to either the bevacizumab group (n=671) or the observation group (n=672). Median follow-up was 25 months (IQR 16-37) in the bevacizumab group and 25 months (17-37) in the observation group. At the time of interim analysis, 286 (21%) of 1343 enrolled patients had died: 140 (21%) of 671 patients in the bevacizumab group, and 146 (22%) of 672 patients in the observation group. 134 (96%) of patients in the bevacizumab group died because of melanoma versus 139 (95%) in the observation group. We noted no significant difference in overall survival between treatment groups (hazard ratio [HR] 0.97, 95% CI 0.78-1.22; p=0.76); this finding persisted after adjustment for stratification variables (HR 1.03; 95% CI 0.81-1.29; p=0.83). Median duration of treatment with bevacizumab was 51 weeks (IQR 21-52) and dose intensity was 86% (41-96), showing good tolerability. 180 grade 3 or 4 adverse events were recorded in 101 (15%) of 671 patients in the bevacizumab group, and 36 (5%) of 672 patients in the observation group. Bevacizumab resulted in a higher incidence of grade 3 hypertension than did observation (41 [6%] vs one [<1%]). There was an improvement in disease-free interval for patients in the bevacizumab group compared with those in the observation group (HR 0.83, 95% CI 0.70-0.98, p=0.03), but no significant difference between groups for distant-metastasis-free interval (HR 0.88, 95% CI 0.73-1.06, p=0.18). No significant differences were noted between treatment groups in the standardised area under the curve for any of the quality-of-life scales over 36 months. Three adverse drug reactions were regarded as both serious and unexpected: one patient had optic neuritis after the first bevacizumab infusion, a second patient had persistent erectile dysfunction, and a third patient died of a haemopericardium after receiving two bevacizumab infusions and was later identified to have had significant predisposing cardiovascular risk factors. INTERPRETATION: Bevacizumab has promising tolerability. Longer follow-up is needed to identify an effect on the primary endpoint of overall survival at 5 years.

Adjuvant treatment strategies for early colon cancer.

Colon cancer remains a major cause of death; however, in the last 3 years a number of trials have been published that have led to changes in the treatment of patients with this disease. Initially, the adjuvant treatment of patients following curative resection was based on their Dukes staging; this is now being refined by consideration of other pathological factors, as well as the investigation of newer prognostic markers such as p53, Ki67 and a number of genes on chromosome 18. Tumours generally develop from the progressive accumulation of genetic events, although some develop through mutation or inactivation of DNA mismatch repair proteins leading to microsatellite instability; this is particularly important in Lynch's syndrome. The loss of gene expression can occur by deletion or mutation of genes or by aberrant methylation of CpG islands. In patients with Dukes C colon cancer the standard of care for adjuvant chemotherapy was previously based on bolus fluorouracil (5-fluorouracil) and folinic acid (leucovorin) administered 5 days per month or weekly for 6 months. Recent studies with a combination of infusional fluorouracil, folinic acid and oxaliplatin have been found to be superior. A further study replacing fluorouracil with oral capecitabine has also demonstrated equivalent disease-free survival. Although some debate remains regarding the benefit of adjuvant treatment for patients with Dukes B colon cancer, the emerging consensus is that, for those patients who are younger and have high-risk features, chemotherapy should be discussed. A number of large vaccine trials have also been conducted in the adjuvant setting and, overall, these have been disappointing. This is a rapidly advancing area of therapy and the results of new trials are awaited to determine whether additional benefits can be achieved with biological therapies such as anti-vascular endothelial growth factor and anti-epithelial growth factor receptor monoclonal antibodies, which have already been shown to be effective in setting of metastatic colon cancer.