Chemotherapy combined with antiangiogenic drugs as salvage therapy in advanced melanoma patients progressing on PD-1 immunotherapy

Background: This study aimed to evaluate the effect of salvage therapy with nab-paclitaxel (nab-p) or temozolomide (TMZ) combined with antiangiogenic drugs in programmed death 1 (PD-1) inhibitor-resistant patients with unresectable metastatic melanoma.

Methods: We conducted a retrospective review of 69 metastatic melanoma patients who received nab-p or TMZ combined with antiangiogenic drugs after developing PD-1 inhibitor resistance and were treated at the Beijing Cancer Hospital between 2016 and 2019. The disease control rate (c-DCR) and progression-free survival (c-PFS) of salvage CA (chemotherapy combined with antiangiogenic drugs) regimens were investigated. Univariate and multivariate analyses were performed to evaluate the clinical pathological factors affecting the outcomes. Then, a nomogram was formulated to predict the probability of 3-month and 6-month c-PFS based on the multivariate analysis results.

Results: The c-DCR was 63.8%, and the median c-PFS was 3.0 months. In the univariate analysis, factors associated with the c-DCR were included the melanoma subtype, baseline platelet-to-lymphocyte ratio (PLR) and best response status to PD-1 inhibitors. Factors influencing c-PFS included age, baseline lactic dehydrogenase, PLR, neutrophil-to-lymphocyte ratio (NLR), PFS duration of anti-PD-1 therapy (p-PFS), and the best response and progression pattern of PD-1 inhibitors. In the multivariate analysis, age <65 years, heterogeneous progression pattern and baseline PLR<200 were significantly associated with improved c-PFS. The concordance index (C-index) of the nomogram was equal to 0.65 (95% CI 0.566-0.734).

Conclusions: CA regimens demonstrated promising effects in PD-1 inhibitor-resistant patients. The nomogram could be a valuable predictive module for salvage therapy choice in PD-1 inhibitor-resistant patients.