Jeffrey S. Weber, MD, PhD, the director of the Donald A. Adam Comprehensive Melanoma Research Center at the Moffitt Cancer Center and Research Institute in Tampa, FL, describes a single institution phase I/II trial exploring the anti-PD-1 antibody nivolumab in combination with a peptide vaccine for patients with unresectable melanoma.
The trial divided 90 patients with unresectable melanoma who were naïve or refractory to ipilimumab into several cohorts to allow for individual analyses. Overall, Weber notes, response rates were similar between patients who were ipilimumab naive (28%) and those who were refractory (32%). Additionally, correlative immune assays were performed to examine possible biomarkers, such as the affect of PD-L1 positivity on response.
The examination of PD-L1 was undertaken to reproduce earlier work suggesting that PD-L1 was a predictive marker of response for nivolumab. Overall, an association between tumor PD-L1 and response was discovered; however, this association was not definitive. In general, Weber notes, patients who did not test positive for PD-L1 still responded to nivolumab.
A 10-year follow-up study of regional melanoma staging strategies found that patients who underwent sentinel-node biopsies had significantly greater disease-free survival rates (DFSRs) compared with patients monitored through nodal observation.