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Antibody targeting of the immune checkpoint receptor PD1 produces therapeutic activity in a variety of solid tumors, but most patients exhibit partial or complete resistance to treatment for reasons that are unclear. In this study, we evaluated tumor specimens from 65 patients with melanoma, lung nonsquamous, squamous cell lung or head and neck cancers who were treated with the approved PD1-targeting antibodies pembrolizumab or nivolumab. Tumor RNA before anti-PD1 therapy was analyzed on the nCounter system using the PanCancer 730-Immune Panel, and we identified 23 immune-related genes or signatures linked to response and progression-free survival (PFS). In addition, we evaluated intra- and interbiopsy variability of PD1, PD-L1, CD8A, and CD4 mRNAs and their relationship with tumor-infiltrating lymphocytes (TIL) and PD-L1 IHC expression. Among the biomarkers examined, PD1 gene expression along with 12 signatures tracking CD8 and CD4 T-cell activation, natural killer cells, and IFN activation associated significantly with nonprogressive disease and PFS. These associations were independent of sample timing, drug used, or cancer type. TIL correlated moderately (∼0.50) with PD1 and CD8A mRNA levels and weakly (∼0.35) with CD4 and PD-L1. IHC expression of PD-L1 correlated strongly with PD-L1 (0.90), moderately with CD4 and CD8A, and weakly with PD1. Reproducibility of gene expression in intra- and interbiopsy specimens was very high (total SD <3%). Overall, our results support the hypothesis that identification of a preexisting and stable adaptive immune response as defined by mRNA expression pattern is reproducible and sufficient to predict clinical outcome, regardless of the type of cancer or the PD1 therapeutic antibody administered to patients. Cancer Res; 77(13); 3540-50. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Purpose: Immunotherapy (IT) agents and BRAF inhibitors (BRAFi) are effective treatments for patients with advanced BRAF-mutant melanoma although the optimal sequence remains to be elucidated. The aim of this study was to compare the outcomes of two different cohorts of patients treated with BRAFi first, then IT or the reverse sequence., Patients and Methods: This is a retrospective study on two groups of patients: a cohort was treated first with BRAFi followed by immunotherapy (BRAFi-IT) and the other cohort with the reverse sequence (IT-BRAFi). Baseline characteristics and clinical outcomes were compared between the two cohorts., Results: A total of 25 patients were included in the study. Sixteen patients were given BRAFi-IT sequence and nine received IT-BRAFi sequence. No differences were observed in the characteristics of patients prior to each treatment between cohorts. Objective response rate (ORR) achieved by BRAFi were not different among groups. ORR achieved by IT was higher when administered after BRAFi (43.8 vs 0 %). Survival rates at 1-2 years were similar in both cohorts and median overall survival was not different for BRAFi-IT and IT-BRAFi (log rank test p = 0.97)., Conclusions: No differences were observed in OS between the two cohorts. These results support the indistinct use of IT or BRAFi as initial treatment in patients with metastatic BRAF-mutant melanoma, although higher rate of response to IT was observed when administered after BRAFi. Prospective randomized clinical trials are needed on this issue.

Aim: While both efficacy and safety of anti-PD-1 agents seem to be independent of previous treatment with anti-CTLA-4, limited data exist of efficacy and toxicity of ipilimumab after progression on anti-PD-1 therapy. This retrospective analysis describes the efficacy and safety of sequential therapy with ipilimumab in patients with metastatic melanoma who progressed on anti-PD-1 antibody., Methods: Nine patients who progressed on anti-PD-1 therapy received four cycles of ipilimumab 3 mg/kg every 3 weeks., Results: Two out of nine patients (2/9; 22.2%) showed a partial response, and seven patients (7/9; 77.8%) experienced disease progression. Median progression-free survival was 3.14 months (95% CI: 2.56-3.71), and the median overall survival since the start of anti-PD-1 therapy was 16.8 months (95% CI: 8.1-25.4). Five (5/9; 55.6%) patients experienced grade 3 immune-related adverse events. No grade 4 or 5 adverse events were reported., Conclusion: In this small retrospective series of cases, the efficacy of ipilimumab post-anti-PD-1 was similar to that described in the previous reports on ipilimumab.

Currently, limited data exist on the safety of pembrolizumab in patients with metastatic melanoma who have developed severe immune-related adverse events following treatment with ipilimumab. We report a 45-year-old male patient with BRAF-mutant metastatic melanoma who discontinued treatment with ipilimumab due to treatment-related grade 3 colitis and was subsequently treated with the anti-programmed cell death 1 protein (PD-1) antibody pembrolizumab. He has been on treatment with pembrolizumab for more than 20 months with no major toxicities and has achieved an objective partial response, which is ongoing.