Monoclonal antibodies targeting immune checkpoints are gaining ground in the treatment of melanoma and other cancers, and considerable effort is made to identify biomarkers predicting the efficacy of these therapies. Our retrospective study was performed on surgical tissue samples (52 lymph nodes and 34 cutaneous/subcutaneous metastases) from 30 patients with metastatic melanoma treated with ipilimumab. Using a panel of 11 antibodies against different immune cell types, intratumoral immune cell densities were determined and evaluated in relation to response to ipilimumab treatment and disease outcome. For most markers studied, median immune cell densities were at least two times higher in lymph node metastases compared to skin/subcutaneous ones; therefore, the prognostic and predictive associations of immune cell infiltration were evaluated separately in the two groups of metastases as well as in all samples as a whole. Higher prevalence of several immune cell types was seen in lymph node metastases of the responders compared to non-responders, particularly FOXP3 cells and CD8 T lymphocytes. In subcutaneous or cutaneous metastases, on the other hand, significant difference could be observed only in the case of CD16 and CD68. Associations of labeled cell densities with survival were also found for most cell types studied in nodal metastases, and for CD16 and CD68 cells in skin/s.c. metastatic cases. Our results corroborate the previous findings suggesting an association between an immunologically active tumor microenvironment and response to ipilimumab treatment, and propose new potential biomarkers for predicting treatment efficacy and disease outcome.

Ipilimumab was the first immunotherapy approved for metastatic melanoma in decades and is currently registered as a second-line treatment. However, new immunotherapies, in combination with ipilimumab, offer even better clinical outcomes for patients compared with single-agent treatments, at the expense of improved toxicity. The aim of this study was to evaluate the feasibility of ipilimumab outside the clinical trials and to identify survival predictors for treatment benefit. Data were collected on 47 advanced melanoma patients treated with ipilimumab between 2010 and 2015 at a single center. Association of clinical characteristics (including primary tumor characteristics), serum lactate dehydrogenase (LDH), erythrocyte sedimentation rate, absolute eosinophil, lymphocyte, and neutrophil count, neutrophil/lymphocyte and eosinophil/lymphocyte ratio with toxicity and clinical outcome were assessed using univariate and multivariate analysis. Median progression-free survival at a median follow-up of 10 months was 2.7 months and median overall survival was 9.8 months. Objective response was observed in 17% of patients and the disease control rate at week 24 was 40%. The 1- and 2-year survival rates documented were 40 and 28%, respectively. Significant association between high LDH level (>1.5× upper limit of normal) and decreased overall survival was demonstrated in uni- and multivariate analysis (hazard ratio [HR]: 3.554, 95% CI: 1.225-10.306, p = 0.019). Neither biomarkers nor clinical outcome were associated with toxicity. Using baseline serum LDH to identify patients most likely to benefit from ipilimumab therapy could serve as a simple and inexpensive biomarker of clinical outcome.

BackgroundThe clinical response to immune checkpoint inhibitors (ICIs) in only part of the treated patients, in conjunction with the potentially serious side effects associated with this type of therapy, has emphasized the need to identify biomarkers to select patients who may benefit from ICI treatment. The aim of our study was to test human leukocyte antigen (HLA) class I and II expression in melanoma metastases as potential biomarkers of response to ipilimumab and survival in patients with metastatic melanoma, since these molecules play a crucial role in the interactions of malignant cells with host’s immune system.Materials and methodsHLA class I and II antigen expression level in pretreatment surgical tissue samples (50 lymph node and 35 cutaneous or subcutaneous metastases) from 30 patients was analyzed by immunohistochemical staining with monoclonal antibodies. Expression levels were correlated to intratumoral density of lymphocytes expressing cluster of differentiation (CD)8, CD45RO, CD4, forkhead box P3 (FOXP3) and/or programmed cell death protein 1 (PD-1), to clinical response to treatment, and to patients’ survival.ResultsHLA class I antigen expression level in lymph node metastases, but not in cutaneous or subcutaneous metastases was significantly correlated to density of CD8+ and CD45RO+ T cells and of lymphocytes expressing PD-1, as well as to clinical response and to patients’ survival.ConclusionsOur results corroborate the role of HLA class I expression level (alone or in combination with T-cell density values) as a predictive biomarker of response to ipilimumab in patients with melanoma. In addition, our results show that this association is influenced by the anatomic site of the metastasis used to measure the HLA class I antigen expression level.

Table of contentsMELANOMA BRIDGE 2015KEYNOTE SPEAKER PRESENTATIONSMolecular and immuno-advancesK1 Immunologic and metabolic consequences of PI3K/AKT/mTOR activation in melanomaVashisht G. Y. Nanda, Weiyi Peng, Patrick Hwu, Michael A. DaviesK2 Non-mutational adaptive changes in melanoma cells exposed to BRAF and MEK inhibitors help the establishment of drug resistanceGennaro Ciliberto, Luigi Fattore, Debora Malpicci, Luigi Aurisicchio, Paolo Antonio Ascierto, Carlo M. Croce, Rita ManciniK3 Tumor-intrinsic beta-catenin signaling mediates tumor-immune avoidanceStefani Spranger, Thomas F. GajewskiK4 Intracellular tumor antigens as a source of targets of antibody-based immunotherapy of melanomaYangyang Wang, Soldano FerroneCombination therapiesK5 Harnessing radiotherapy to improve responses to immunotherapy in cancerClaire Vanpouille-Box, Erik Wennerberg, Karsten A. Pilones, Silvia C. Formenti, Sandra DemariaK6 Creating a T cell-inflamed tumor microenvironment overcomes resistance to checkpoint blockadeHaidong Tang, Yang Wang, Yang-Xin FuK7 Biomarkers for treatment decisions?Reinhard DummerK8 Combining oncolytic therapies in the era of checkpoint inhibitorsIgor PuzanovK9 Immune checkpoint blockade for melanoma: should we combine or sequence ipilimumab and PD-1 antibody therapy?Michael A. PostowNews in immunotherapyK10 An update on adjuvant and neoadjuvant therapy for melanomAhmad TarhiniK11 Targeting multiple inhibitory receptors in melanomaJoe-Marc Chauvin, Ornella Pagliano, Julien Fourcade, Zhaojun Sun, Hong Wang, Cindy Sanders, John M. Kirkwood, Tseng-hui Timothy Chen, Mark Maurer, Alan J. Korman, Hassane M. ZarourK12 Improving adoptive immune therapy using genetically engineered T cellsDavid F. StroncekTumor microenvironment and biomarkersK13 Myeloid cells and tumor exosomes: a crosstalk for assessing immunosuppression?Veronica Huber, Licia RivoltiniK14 Update on the SITC biomarker taskforce: progress and challengesMagdalena ThurinWorld-wide immunoscore task force: an updateK15 The immunoscore in colorectal cancer highlights the importance of digital scoring systems in surgical pathologyTilman Rau, Alessandro LugliK16 The immunoscore: toward an integrated immunomonitoring from the diagnosis to the follow up of cancer’s patientsFranck PagèsEconomic sustainability of melanoma treatments: regulatory, health technology assessment and market access issuesK17 Nivolumab, the regulatory experience in immunotherapyJorge Camarero, Arantxa SanchoK18 Evidence to optimize access for immunotherapiesClaudio JommiORAL PRESENTATIONSMolecular and immuno-advancesO1 Ipilimumab treatment results in CD4 T cell activation that is concomitant with a reduction in Tregs and MDSCsYago Pico de Coaña, Maria Wolodarski, Yuya Yoshimoto, Giusy Gentilcore, Isabel Poschke, Giuseppe V. Masucci, Johan Hansson, Rolf KiesslingO2 Evaluation of prognostic and therapeutic potential of COX-2 and PD-L1 in primary and metastatic melanomaGiosuè Scognamiglio, Francesco Sabbatino, Federica Zito Marino, Anna Maria Anniciello, Monica Cantile, Margherita Cerrone,...

No abstract