Immunogenicity in humans of a transdermal multipeptide melanoma vaccine administered with or without a TLR7 agonist.

Background: Experimental cancer vaccines are traditionally administered by injection in subcutaneous tissue or muscle, commonly with adjuvants that create chronic inflammatory depots. Injection of melanoma-derived peptides induces T cell responses; however, the depots that form following injection may inhibit optimization of the immune response. In skin, epidermal Langerhans cells (LC) are a dominant source of professional antigen presenting cells.

Trial to evaluate the immunogenicity and safety of a melanoma helper peptide vaccine plus incomplete Freund's adjuvant, cyclophosphamide, and polyICLC (Mel63).

Background: Peptide vaccines designed to stimulate melanoma-reactive CD4 T cells can induce T cell and antibody (Ab) responses, associated with enhanced overall survival. We hypothesized that adding toll-like receptor 3 agonist polyICLC to an incomplete Freund's adjuvant (IFA) would be safe and would support strong, durable CD4 T cell and Ab responses. We also hypothesized that oral low-dose metronomic cyclophosphamide (mCy) would be safe, would reduce circulating regulatory T cells (T-regs) and would further enhance immunogenicity.

Characterization and comparison of innate and adaptive immune responses at vaccine sites in melanoma vaccine clinical trials.

The strength and durability of systemic anti-tumor immune responses induced by cancer vaccines depends on adjuvants to support an immunogenic vaccine site microenvironment (VSME). Adjuvants include water-in-oil emulsions with incomplete Freund's adjuvant (IFA) and combinations of toll-like receptor (TLR) agonists, including a preparation containing TLR4 and TLR9 agonists with QS-21 (AS15). IFA-containing vaccines can promote immune cell accumulation at the VSME, whereas effects of AS15 are largely unexplored.

A multipeptide vaccine plus toll-like receptor agonists LPS or polyICLC in combination with incomplete Freund's adjuvant in melanoma patients.

Background: Cancer vaccines require adjuvants to induce effective immune responses; however, there is no consensus on optimal adjuvants. We hypothesized that toll-like receptor (TLR)3 agonist polyICLC or TLR4 agonist lipopolysaccharide (LPS), combined with CD4 T cell activation, would support strong and durable CD8 T cell responses, whereas addition of an incomplete Freund's adjuvant (IFA) would reduce magnitude and persistence of immune responses.

Patients And Methods: Participants with resected stage IIB-IV melanoma received a vaccine comprised of 12 melanoma peptides restricted by Class I MHC (12MP), plus a tetanus helper peptide (Tet).

Patterns of immune-cell infiltration in murine models of melanoma: roles of antigen and tissue site in creating inflamed tumors.

Immune-cell infiltration is associated with improved survival in melanoma. Human melanoma metastases may be grouped into immunotypes representing patterns of immune-cell infiltration: A (sparse), B (perivascular cuffing), and C (diffuse). Immunotypes have not been defined for murine melanomas, but may provide opportunities to understand mechanism-driving immunotype differences.

Human melanomas and ovarian cancers overexpressing mechanical barrier molecule genes lack immune signatures and have increased patient mortality risk.

We have identified eight genes whose expression in human melanoma metastases and ovarian cancers is associated with a lack of Th1 immune signatures. They encode molecules with mechanical barrier function in the skin and other normal tissues and include filaggrin (FLG), tumor-associated calcium signal transducer 2 (TACSTD2), and six desmosomal proteins (DST, DSC3, DSP, PPL, PKP3, and JUP). This association has been validated in an independent series of 114 melanoma metastases.

PD-L1, PD-L2 and PD-1 expression in metastatic melanoma: Correlation with tumor-infiltrating immune cells and clinical outcome.

Therapeutic blockade of PD-1/PD-L1 can have dramatic therapeutic benefit in some patients; however, the prognostic associations of PD-1 and its ligands, in the absence of therapeutic blockade have not been definitively addressed. In particular, associations of PD-L2 with immune infiltrates and with outcome have yet to be explored. We hypothesized that surface expression of both PD-L1 and PD-L2 by melanoma cells would be associated with immune cell infiltration and with overall patient survival, independent of checkpoint blockade therapy.

Heterogeneity of CD8 tumor-infiltrating lymphocytes in non-small-cell lung cancer: impact on patient prognostic assessments and comparison of quantification by different sampling strategies.

Introduction: Infiltration of non-small-cell lung cancer (NSCLC) by CD8 T lymphocytes predicts improved patient survival; however, heterogeneity of intratumoral localization complicates this assessment. Strategies for tumor sampling may not accurately represent the whole tumor. We hypothesized that sampling strategies may alter the identification of tumors with high CD8 density and affect the prognostic significance.

Topical treatment of melanoma metastases with imiquimod, plus administration of a cancer vaccine, promotes immune signatures in the metastases.

Introduction: Infiltration of cancers by T cells is associated with improved patient survival and response to immune therapies; however, optimal approaches to induce T cell infiltration of tumors are not known. This study was designed to assess whether topical treatment of melanoma metastases with the TLR7 agonist imiquimod plus administration of a multipeptide cancer vaccine will improve immune cell infiltration of melanoma metastases.

Patients And Methods: Eligible patients were immunized with a vaccine comprised of 12 melanoma peptides and a tetanus toxoid-derived helper peptide, and imiquimod was applied topically to metastatic tumors daily.

Intratumoral interferon-gamma increases chemokine production but fails to increase T cell infiltration of human melanoma metastases.

Introduction: Optimal approaches to induce T cell infiltration of tumors are not known. Chemokines CXCL9, CXCL10, and CXCL11 support effector T cell recruitment and may be induced by IFN. This study tests the hypothesis that intratumoral administration of IFNγ will induce CXCL9-11 and will induce T cell recruitment and anti-tumor immune signatures in melanoma metastases.

Biomarkers of immunogenic stress in metastases from melanoma patients: Correlations with the immune infiltrate.

Melanoma is known to be under latent immunosurveillance. Here, we studied four biomarkers of immunogenic cell stress and death (microtubule-associated proteins 1A/1B light chain 3B (MAP-LC3B, best known as LC3B)-positive puncta in the cytoplasm as a sign of autophagy; presence of nuclear HMGB1; phosphorylation of eIF2α; increase in ploidy) in melanoma cells, in tissue microarrays (TMA) from metastases from 147 melanoma patients. These biomarkers of immunogenicity were correlated with the density of immune cells infiltrating the metastases and expressing CD3, CD4(+), CD8(+), CD20, CD45, CD56, CD138, CD163, DC-LAMP or FOXP3.

A randomized pilot trial testing the safety and immunologic effects of a MAGE-A3 protein plus AS15 immunostimulant administered into muscle or into dermal/subcutaneous sites.

Introduction: Methods to induce T cell responses to protein vaccines have not been optimized. The immunostimulant AS15 has been administered with the recombinant MAGE-A3 protein (recMAGE-A3) i.m.

TLR2/6 agonists and interferon-gamma induce human melanoma cells to produce CXCL10.

Clinical approaches to treat advanced melanoma include immune therapies, whose benefits depend on tumor-reactive T-cell infiltration of metastases. However, most tumors lack significant immune infiltration prior to therapy. Selected chemokines promote T-cell migration into tumors; thus, agents that induce these chemokines in the tumor microenvironment (TME) may improve responses to systemic immune therapy.

MHC-restricted phosphopeptides from insulin receptor substrate-2 and CDC25b offer broad-based immunotherapeutic agents for cancer.

Cancer cells display novel phosphopeptides in association with MHC class I and II molecules. In this study, we evaluated two HLA-A2-restricted phosphopeptides derived from the insulin receptor substrate (IRS)-2 and the cell-cycle regulator CDC25b. These proteins are both broadly expressed in multiple malignancies and linked to cancer cell survival.

A melanoma helper peptide vaccine increases Th1 cytokine production by leukocytes in peripheral blood and immunized lymph nodes.

Background: Cancers produce soluble and cell-associated molecules that can suppress or alter antitumor immunity. Preclinical studies suggest the disease burden may alter the cytokine profile of helper T cell responses to cancer antigens. We studied cytokine production by helper T cells responding to vaccination with 6 melanoma helper peptides (6MHP) in blood and lymph nodes.

A case of spontaneous systemic immunity to melanoma associated with cure after amputation for extensive regional recurrence.

Purpose: Survival after amputation for melanoma is short; however, rare long-term survivors are reported. The mechanism for durable systemic tumor control in patients with regional failure is not known. To explore whether systemic tumor immunity may be implicated, tumor and circulating immune responses were examined in a patient who survived disease-free 14 years after hip disarticulation.

Immunotype and immunohistologic characteristics of tumor-infiltrating immune cells are associated with clinical outcome in metastatic melanoma.

Immune cells infiltrating the microenvironment of melanoma metastases may either limit or promote tumor progression, but the characteristics that distinguish these effects are obscure. In this study, we systematically evaluated the composition and organization of immune cells that infiltrated melanoma metastases in human patients. Three histologic patterns of immune cell infiltration were identified, designated immunotypes A, B, and C.

The vaccine-site microenvironment induced by injection of incomplete Freund's adjuvant, with or without melanoma peptides.

Cancer vaccines have not been optimized. They depend on adjuvants to create an immunogenic microenvironment for antigen presentation. However, remarkably little is understood about cellular and molecular changes induced by these adjuvants in the vaccine microenvironment.

VEGFR-2 expression in human melanoma: revised assessment.

Vascular endothelial growth factor (VEGF) is an angiogenic factor that also functions as an autocrine growth factor for VEGF receptor (VEGFR)-2(+) melanomas. In multiple studies, VEGFR-2 was detected by immunostaining in 78-89% of human melanoma cells, suggesting that most patients with melanoma would benefit from anti-VEGF therapy. Here, we evaluated 167 human melanoma specimens in a tissue microarray to verify the presence of VEGFR-2, but found disparities in staining with commercial antibodies A-3 and 55B11.

Dynamic changes in cellular infiltrates with repeated cutaneous vaccination: a histologic and immunophenotypic analysis.

Background: Melanoma vaccines have not been optimized. Adjuvants are added to activate dendritic cells (DCs) and to induce a favourable immunologic milieu, however, little is known about their cellular and molecular effects in human skin. We hypothesized that a vaccine in incomplete Freund's adjuvant (IFA) would increase dermal Th1 and Tc1-lymphocytes and mature DCs, but that repeated vaccination may increase regulatory cells.

The use of gamma-irradiation and ultraviolet-irradiation in the preparation of human melanoma cells for use in autologous whole-cell vaccines.

Background: Human cancer vaccines incorporating autologous tumor cells carry a risk of implantation and subsequent metastasis of viable tumor cells into the patient who is being treated. Despite the fact that the melanoma cell preparations used in a recent vaccine trial (Mel37) were gamma-irradiated (200 Gy), approximately 25% of the preparations failed quality control release criteria which required that the irradiated cells incorporate 3H-thymidine at no more than 5% the level seen in the non-irradiated cells. We have, therefore, investigated ultraviolet (UV)-irradiation as a possible adjunct to, or replacement for gamma-irradiation.

Helper T-cell responses and clinical activity of a melanoma vaccine with multiple peptides from MAGE and melanocytic differentiation antigens.

Purpose: A phase I/II trial was performed to evaluate the safety and immunogenicity of a novel melanoma vaccine comprising six melanoma-associated peptides defined as antigenic targets for melanoma-reactive helper T cells. Source proteins for these peptides include MAGE proteins, MART-1/MelanA, gp100, and tyrosinase.

Patients And Methods: Thirty-nine patients with stage IIIB to IV melanoma were vaccinated with this six-peptide mixture weekly at three dose levels, with a preceding phase I dose escalation and subsequent random assignment among the dose levels.

Sequential immune escape and shifting of T cell responses in a long-term survivor of melanoma.

Immune-mediated control of tumors may occur, in part, through lysis of malignant cells by CD8(+) T cells that recognize specific Ag-HLA class I complexes. However, tumor cell populations may escape T cell responses by immune editing, by preventing formation of those Ag-HLA complexes. It remains unclear whether the human immune system can respond to immune editing and recognize newly arising escape variants.

Immunologic and clinical outcomes of vaccination with a multiepitope melanoma peptide vaccine plus low-dose interleukin-2 administered either concurrently or on a delayed schedule.

Purpose: A phase II trial was performed to test whether systemic low-dose interleukin-2 (IL-2) augments T-cell immune responses to a multipeptide melanoma vaccine. Forty patients with resected stage IIB-IV melanoma were randomly assigned to vaccination with four gp100- and tyrosinase-derived peptides restricted by human leukocyte antigen (HLA) -A1, HLA-A2, and HLA-A3, and a tetanus helper peptide plus IL-2 administered daily either beginning day 7 (group 1), or beginning day 28 (group 2).

Patients And Methods: T-cell responses were assessed by an interferon gamma ELIspot assay in peripheral blood lymphocytes (PBL) and in a lymph node draining a vaccination site (sentinel immunized node [SIN]).

Competition among peptides in melanoma vaccines for binding to MHC molecules.

The effectiveness of peptide-based cancer vaccines depends on the ability of peptides to bind to MHC molecules on the surface of antigen-presenting cells, where they reconstitute epitopes for cytotoxic T lymphocytes (CTLs). Multivalent vaccines have advantages over single-peptide vaccines; however, peptides may compete for binding to the same MHC molecules. In particular, it is possible that peptides with high affinity for MHC molecules prevent the binding of lower-affinity peptides.