Putative Cancer Stem Cell Markers are Frequently Expressed by Melanoma Cells and but are also Present in Benign Differentiated Cells.

Background: Currently, there remains an incomplete view of cancer stem cells (CSCs) in solid tumours.

Methods: We studied a panel of putative CSC surface markers (ALDH1A1, ABCG2, CD44v7/8, CD44v10, CD133, CD271, and Nestin) in 40 established melanoma cell lines and four early-passage melanoma strains by flow cytometry. We additionally examined 40 formalin-fixed paraffin-embedded melanoma tissues using immunofluorescence microscopy.

Correlation of Baseline Tumor Burden with Clinical Outcome in Melanoma Patients Treated with Ipilimumab.

Introduction: Tumor burden is a frequently mentioned parameter; however, a commonly accepted definition is still lacking.

Methods: In this double-center prospective and retrospective study, 76 patients with unresectable stage III or stage IV melanoma treated with ipilimumab were included. We defined the baseline tumor burden (BTB) as the global sum of all metastases' longest diameters before treatment started and correlated the calculated BTB with disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and with the baseline levels of LDH, S100B, and sULPB2.

Tumor-derived GDF-15 blocks LFA-1 dependent T cell recruitment and suppresses responses to anti-PD-1 treatment.

Immune checkpoint blockade therapy is beneficial and even curative for some cancer patients. However, the majority don't respond to immune therapy. Across different tumor types, pre-existing T cell infiltrates predict response to checkpoint-based immunotherapy.

Early decrease of blood myeloid-derived suppressor cells during checkpoint inhibition is a favorable biomarker in metastatic melanoma.

Background: The need for reliable clinical biomarkers to predict which patients with melanoma will benefit from immune checkpoint blockade (ICB) remains unmet. Several different parameters have been considered in the past, including routine differential blood counts, T cell subset distribution patterns and quantification of peripheral myeloid-derived suppressor cells (MDSC), but none has yet achieved sufficient accuracy for clinical utility.

Methods: Here, we investigated potential cellular biomarkers from clinical routine blood counts as well as several myeloid and T cell subsets, using flow cytometry, in two independent cohorts of a total of 141 patients with stage IV M1c melanoma before and during ICB.

Dynamics of Melanoma-Associated Epitope-Specific CD8+ T Cells in the Blood Correlate With Clinical Outcome Under PD-1 Blockade.

Immune checkpoint blockade (ICB) is standard-of-care for patients with metastatic melanoma. It may re-invigorate T cells recognizing tumors, and several tumor antigens have been identified as potential targets. However, little is known about the dynamics of tumor antigen-specific T cells in the circulation, which might provide valuable information on ICB responses in a minimally invasive manner.

Chemotherapy after immune checkpoint inhibitor failure in metastatic melanoma: a retrospective multicentre analysis.

Introduction: Despite remarkably improved outcomes with immune checkpoint inhibition, many patients with metastatic melanoma will eventually require further therapy. Chemotherapy has limited activity when used first-line but can alter the tumour microenvironment and does improve efficacy when used in combination with immunotherapy in lung cancer. Whether chemotherapy after checkpoint inhibitor failure has relevant activity in patients with metastatic melanoma is unknown.

Pretreatment metastatic growth rate determines clinical outcome of advanced melanoma patients treated with anti-PD-1 antibodies: a multicenter cohort study.

Background: Checkpoint inhibitors revolutionized the treatment of metastatic melanoma patients. Although tumor burden and lactate dehydrogenase (LDH) are associated with overall survival (OS), the impact of tumor growth kinetics remains elusive and in part contradictory. The aims of this study were to develop a novel simple and rapid method that estimates pretreatment metastatic growth rate (MGR) and to investigate its prognostic impact in melanoma patients treated with antiprogrammed death receptor-1 (PD-1) antibodies.

Serum S100B and LDH at Baseline and During Therapy Predict the Outcome of Metastatic Melanoma Patients Treated with BRAF Inhibitors.

Background: Despite impressive response rates, most patients with advanced melanoma ultimately progress following therapy with B-Raf proto-oncogene (BRAF) inhibitors (BRAFi). Therefore, frequent radiologic assessments are necessary, and reliable serum biomarkers would be beneficial for disease monitoring.

Objective: This study investigated the ability of lactate dehydrogenase (LDH) and S100 calcium-binding protein B (S100B) to detect response and disease progression during treatment with BRAFi.

Serum CD73 is a prognostic factor in patients with metastatic melanoma and is associated with response to anti-PD-1 therapy.

Background: Inhibitors of immune checkpoint programmed cell death protein 1 (PD-1) receptor on T cells have shown remarkable clinical outcomes in metastatic melanoma. However, most patients are resistant to therapy. Production of extracellular adenosine, via CD73-mediated catabolism of AMP, contributes to suppress T-cell-mediated responses against cancer.

Prognostic role of gamma-glutamyl transferase in metastatic melanoma patients treated with immune checkpoint inhibitors.

Background: Hepatic immune-related adverse events (irAE) including elevated liver function tests (transaminases) occur in 1.4-22.3% of melanoma patients receiving immune checkpoint inhibitors (ICPI) and constitute a potentially serious toxicity that is challenging to treat.

Is there a link between very early changes of primary and secondary lymphoid organs in F-FDG-PET/MRI and treatment response to checkpoint inhibitor therapy?

Response assessment or prediction to checkpoint inhibitor therapy (CIT) is an unsolved problem in current routine diagnostics of patients with melanoma. Here, we evaluated very early changes of primary and secondary lymphoid organs under CIT in multiparametric [F]-labeled fluorodeoxyglucose-positron emission tomography (F-FDG-PET)/MRI as possible predictors of treatment response and investigated their correlation with baseline blood immune biomarkers. Between October 2014 and November 2017, 17 patients with unresectable melanoma (8 females; 65±11 years) undergoing CIT were prospectively evaluated using whole-body F-FDG-PET/MRI before CIT start (t), 2 weeks (t) and 3 months after CIT initiation (t).

Dermatofluoroscopy diagnostics in different pigmented skin lesions: Strengths and weaknesses.

Background: The melanin fluorescence of skin lesions is measurable with two-photon excitation, a process termed dermatofluoroscopy, which has shown a shift from the green spectra in benign melanocytic lesions to the red spectra in melanoma. This study addressed the question as to which kind of pigmented lesions can be correctly diagnosed as melanin-bearing malignant tumors.

Methods: 476 pigmented lesions including 101 cutaneous melanomas were analyzed with dermatofluoroscopy, measuring the melanin fluorescence in a grid-like fashion with a separation of measurement points of 0.

Immune Signatures and Survival of Patients With Metastatic Melanoma, Renal Cancer, and Breast Cancer.

Despite remarkable recent progress in treating solid cancers, especially the success of immunomodulatory antibody therapies for numerous different cancer types, it remains the case that many patients fail to respond to treatment. It is therefore of immense importance to identify biomarkers predicting clinical responses to treatment and patient survival, which would not only assist in targeting treatments to patients most likely to benefit, but might also provide mechanistic insights into the reasons for success or failure of the therapy. Several peripheral blood or tumor tissue diagnostic and predictive biomarkers known to be informative for cancer patient survival may be applicable for this purpose.

Impact of a preceding radiotherapy on the outcome of immune checkpoint inhibition in metastatic melanoma: a multicenter retrospective cohort study of the DeCOG.

Background: Immune checkpoint inhibition (ICI) is an essential treatment option in melanoma. Its outcome may be improved by a preceding radiation of metastases. This study aimed to investigate the impact of a preceding radiotherapy on the clinical outcome of ICI treatment.

Pitfalls in the characterization of circulating and tissue-resident human γδ T cells.

Dissection of the role and function of human γδ T cells and their heterogeneous subsets in cancer, inflammation, and auto-immune diseases is a growing and dynamic research field of increasing interest to the scientific community. Therefore, harmonization and standardization of techniques for the characterization of peripheral and tissue-resident γδ T cells is crucial to facilitate comparability between published and emerging research. The application of commercially available reagents to classify γδ T cells, in particular the combination of multiple Abs, is not always trouble-free, posing major demands on researchers entering this field.

Cancer immunotherapy is accompanied by distinct metabolic patterns in primary and secondary lymphoid organs observed by non-invasive F-FDG-PET.

Cancer immunotherapy depends on a systemic immune response, but the basic underlying mechanisms are still largely unknown. Despite the very successful and widespread use of checkpoint inhibitors in the clinic, the majority of cancer patients do not benefit from this type of treatment. In this translational study, we investigated whether noninvasive positron emission tomography (PET) imaging using 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) is capable of detecting immunotherapy-associated metabolic changes in the primary and secondary lymphoid organs and whether this detection enables the prediction of a successful anti-cancer immune response.

Tumor microenvironment-derived S100A8/A9 is a novel prognostic biomarker for advanced melanoma patients and during immunotherapy with anti-PD-1 antibodies.

Background: Predicting metastasis in melanoma patients is important for disease management and could help to identify those who might benefit from adjuvant treatment. The aim of this study was to investigate whether the tumor microenvironment-derived protein S100A8/A9 qualifies as prognostic marker for melanoma patients, also in the setting of immunotherapy.

Methods: S100A8/A9 gene and protein expression were analyzed on melanocytic nevi, primary melanomas and metastases using a cDNA library and three independent tissue-microarrays (TMA).

A new synthetic toll-like receptor 1/2 ligand is an efficient adjuvant for peptide vaccination in a human volunteer.

Background: We previously showed that the bacterial lipopeptide PamCys-Ser-Ser, meanwhile established as a toll-like receptor (TLR) 1/2 ligand, acts as a strong adjuvant for the induction of virus specific CD8 T cells in mice, when covalently coupled to a synthetic peptide.

Case Presentation: We now designed a new water-soluble synthetic PamCys-derivative, named XS15 and characterized it in vitro by a TLR2 NF-κB luciferase reporter assay. Further, the capacity of XS15 to activate immune cells and stimulate peptide-specific CD8 T and NK cells by 6-sulfo LacNAc monocytes was assessed by flow cytometry as well as cytokine induction using immunoassays.

Targeting tumor-resident mast cells for effective anti-melanoma immune responses.

Immune checkpoint blockade has revolutionized cancer treatment. Patients developing immune mediated adverse events, such as colitis, appear to particularly benefit from immune checkpoint inhibition. Yet, the contributing mechanisms are largely unknown.

A phase II study of the L19IL2 immunocytokine in combination with dacarbazine in advanced metastatic melanoma patients.

Engineered cytokine products represent promising agents for the treatment of immunogenic tumors, such as malignant melanoma, in addition to immune checkpoint inhibitors. Here we describe the results of a controlled, randomized phase II clinical trial, aimed at assessing the therapeutic potential of L19IL2, a fully human fusion protein consisting of the L19 antibody specific to the alternatively spliced extra-domain B of fibronectin, fused to human interleukin-2 in advanced metastatic melanoma. In one arm, patients received dacarbazine (DTIC; 1000 mg/m of body surface on day 1 of 21-day cycles) as single agent, while in two other arms L19IL2 (22.

Peripheral PD-1+CD56+ T-cell frequencies correlate with outcome in stage IV melanoma under PD-1 blockade.

Immune checkpoint blockade with anti-PD-1 antibodies is showing great promise for patients with metastatic melanoma and other malignancies, but despite good responses by some patients who achieve partial or complete regression, many others still do not respond. Here, we sought peripheral blood T-cell biomarker candidates predicting treatment outcome in 75 stage IV melanoma patients treated with anti-PD-1 antibodies. We investigated associations with clinical response, progression-free survival (PFS) and overall survival (OS).