Two cases of dabrafenib and trametinib therapy-failed advanced melanoma successfully controlled by nivolumab monotherapy.

Although therapies for advanced melanoma have been greatly improved by the development of immune checkpoint inhibitors and BRAF/mitogen-activated protein kinase kinase inhibitors, there are still many concerns about the administration of these novel drugs. Therefore, to combine these therapies sequentially at appropriate time points of the disease is important. In this report, we report two cases in which dabrafenib and trametinib therapy for advanced melanoma failed but were successfully controlled by nivolumab monotherapy, and investigated the sera sCD163, CCL22 and CXCL10 as biomarkers for tumor progression. Interestingly, the sera levels of sCD163, CXCL10 and CCL22, both of which are produced by activated tumor-associated macrophages, were increased in parallel with the tumor progression in each case. Because this report presents only two cases, further data will need to be accumulated to provide more fundamental insights into the usefulness of these biomarkers for predicting disease progression in melanoma.