A randomized controlled phase II clinical trial on mRNA electroporated autologous monocyte-derived dendritic cells (TriMixDC-MEL) as adjuvant treatment for stage III/IV melanoma patients who are disease-free following the resection of macrometastases.

Background: Autologous monocyte-derived mRNA co-electroporated dendritic cells with mRNA encoding CD40 ligand (CD40L), CD70 and a constitutively activated TLR4 (caTLR4) (referred to as TriMixDC-MEL) have anti-tumor activity in advanced melanoma patients. We investigated the safety and activity of adjuvant TriMixDC-MEL in stage III/IV melanoma patients.

Materials And Methods: Forty-one patients were randomly assigned to treatment with TriMixDC-MEL (n = 21) and standard follow-up (n = 20).

TriMix and tumor antigen mRNA electroporated dendritic cell vaccination plus ipilimumab: link between T-cell activation and clinical responses in advanced melanoma.

Background: We previously reported that dendritic cell-based mRNA vaccination plus ipilimumab (TriMixDC-MEL IPI) results in an encouraging rate of tumor responses in patients with pretreated advanced melanoma. Here, we report the TriMixDC-MEL IPI-induced T-cell responses detected in the peripheral blood.

Methods: Monocyte-derived dendritic cells electroporated with mRNA encoding CD70, CD40 ligand, and constitutively active TLR4 (TriMix) as well as the tumor-associated antigens tyrosinase, gp100, MAGE-A3, or MAGE-C2 were administered together with IPI for four cycles.

Single Domain Antibody-Mediated Blockade of Programmed Death-Ligand 1 on Dendritic Cells Enhances CD8 T-cell Activation and Cytokine Production.

Dendritic cell [DC] vaccines can induce durable clinical responses, at least in a fraction of previously treated, late stage cancer patients. Several preclinical studies suggest that shielding programmed death-ligand 1 [PD-L1] on the DC surface may be an attractive strategy to extend such clinical benefits to a larger patient population. In this study, we evaluated the use of single domain antibody [sdAb] K2, a high affinity, antagonistic, PD-L1 specific sdAb, for its ability to enhance DC mediated T-cell activation and benchmarked it against the use of the monoclonal antibodies [mAbs], MIH1, 29E.

Evaluating a Single Domain Antibody Targeting Human PD-L1 as a Nuclear Imaging and Therapeutic Agent.

The PD-1:PD-L1 immune checkpoint axis is central in the escape of cancer cells from anticancer immune responses. Monoclonal antibodies (mAbs) specific for PD-L1 have been approved for treatment of various cancer types. Although PD-L1 blockade has proven its merit, there are still several aspects that require further attention to fully capitalize on its potential.

Impact of lenalidomide maintenance on the immune environment of multiple myeloma patients with low tumor burden after autologous stem cell transplantation.

Lenalidomide is a potent anti-myeloma drug with immunomodulatory properties. It is increasingly used in a low-dose maintenance setting to prolong remission duration after standard treatment. Data on the effects of lenalidomide are scarce and sometimes different from the well-described effects.

mRNA Electroporation of Dendritic Cells with WT1, Survivin, and TriMix (a Mixture of caTLR4, CD40L, and CD70).

The immune system is a crucial player in the development of cancer. Once it is in imbalance and immunosuppressive mechanisms supporting tumor growth take over control, dendritic cell immunotherapy might offer a solution to restore the balance. There are several methods to manufacture dendritic cells but none of them has yet proven to be superior to others.

Phase II Study of Autologous Monocyte-Derived mRNA Electroporated Dendritic Cells (TriMixDC-MEL) Plus Ipilimumab in Patients With Pretreated Advanced Melanoma.

Purpose: Autologous monocyte-derived dendritic cells (DCs) electroporated with synthetic mRNA (TriMixDC-MEL) are immunogenic and have antitumor activity as a monotherapy in patients with pretreated advanced melanoma. Ipilimumab, an immunoglobulin G1 monoclonal antibody directed against the cytotoxic T-lymphocyte-associated protein 4 receptor that counteracts physiologic suppression of T-cell function, improves the overall survival of patients with advanced melanoma. This phase II study investigated the combination of TriMixDC-MEL and ipilimumab in patients with pretreated advanced melanoma.

Long-term clinical outcome of melanoma patients treated with messenger RNA-electroporated dendritic cell therapy following complete resection of metastases.

Purpose: Melanoma patients with a high risk of recurrence may benefit from immunotherapy with mRNA-electroporated autologous monocyte-derived dendritic cells (DCs). Further benefit may be found in combining DC-therapy with interferon alfa-2b.

Patients And Methods: The long-term clinical outcome of AJCC stage III/IV melanoma patients who had no evidence of disease at the time of treatment with autologous mRNA-electroporated DCs in a single-center pilot clinical trial was analyzed.

AZD1480 delays tumor growth in a melanoma model while enhancing the suppressive activity of myeloid-derived suppressor cells.

AZD1480 is a potent, competitive small-molecule inhibitor of JAK1/2 kinase which inhibits STAT3 phosphorylation and tumor growth. Here we investigated the effects of AZD1480 on the function of different immune cell populations in a melanoma model. When MO4 tumor-bearing mice were treated with AZD1480 we observed a strong inhibition of tumor growth as well as a prolonged survival.

Immunomodulatory drugs improve the immune environment for dendritic cell-based immunotherapy in multiple myeloma patients after autologous stem cell transplantation.

Multiple myeloma (MM) is characterized by a malignant proliferation of plasma cells in the bone marrow with associated organ damage. Although the prognosis of MM has improved recently, the disease remains incurable for the large majority of patients. The eradication of residual disease in the bone marrow is a main target on the road toward cure.

Optimized dendritic cell-based immunotherapy for melanoma: the TriMix-formula.

Since decades, the main goal of tumor immunologists has been to increase the capacity of the immune system to mediate tumor regression. In this regard, one of the major focuses of cancer immunotherapy has been the design of vaccines promoting strong tumor-specific cytotoxic T lymphocyte responses in cancer patients. Here, dendritic cells (DCs) play a pivotal role as they are regarded as nature's adjuvant and as such have become the natural agents for antigen delivery in order to finally elicit strong T cell responses (Villadangos and Schnorrer in Nat Rev Immunol 7:543-555, 2007; Melief in Immunity 29:372-383, 2008; Palucka and Banchereau in Nat Rev Cancer 12:265-277, 2012; Vacchelli et al.

Interference with PD-L1/PD-1 co-stimulation during antigen presentation enhances the multifunctionality of antigen-specific T cells.

The release of cytokines by T cells strongly defines their functional activity in vivo. The ability to produce multiple cytokines has been associated with beneficial immune responses in cancer and infectious diseases, while their progressive loss is associated with T-cell exhaustion, senescence and anergy. Consequently, strategies that enhance the multifunctional status of T cells are a key for immunotherapy.

Design of an Optimized Wilms' Tumor 1 (WT1) mRNA Construct for Enhanced WT1 Expression and Improved Immunogenicity In Vitro and In Vivo.

Tumor antigen-encoding mRNA for dendritic cell (DC)-based vaccination has gained increasing popularity in recent years. Within this context, two main strategies have entered the clinical trial stage: the use of mRNA for ex vivo antigen loading of DCs and the direct application of mRNA as a source of antigen for DCs in vivo. DCs transfected with mRNA-encoding Wilms' tumor 1 (WT1) protein have shown promising clinical results.

A phase IB study on intravenous synthetic mRNA electroporated dendritic cell immunotherapy in pretreated advanced melanoma patients.

Background: Autologous monocyte-derived dendritic cells (DCs) electroporated with synthetic messenger RNA (mRNA) encoding a CD40 ligand, a constitutively active Toll-like receptor 4 and CD70, together with mRNA encoding fusion proteins of a human leukocyte antigen (HLA)-class II targeting signal (DC-LAMP) and a melanoma-associated antigen (MAA); either MAGE-A3, MAGE-C2, tyrosinase or gp100) (TriMixDC-MEL) are superiorly immunogenic.

Patients And Methods: In this phase IB clinical trial, 24 million viable DCs were administered by four biweekly combined intradermal (id) and intravenous (iv) administrations, and a fifth administration on week 16. The number of iv-administered DCs was escalated in four sequentially treated cohorts.

Modulation of regulatory T cell function by monocyte-derived dendritic cells matured through electroporation with mRNA encoding CD40 ligand, constitutively active TLR4, and CD70.

Regulatory T cells (Tregs) counteract anticancer immune responses through a number of mechanisms, limiting dendritic cell (DC)-based anticancer immunotherapy. In this study, we investigated the influence of various DC activation stimuli on the Treg functionality. We compared DCs activated by electroporation with mRNA encoding constitutively active TLR4 (caTLR4) and CD40 ligand (DiMix-DCs), or these factors together with mRNA encoding the costimulatory molecule CD70 (TriMix-DCs) with DCs maturated in the presence of a mixture of inflammatory cytokines (DCs maturated with a combination of the cytokines IL-1β, IL-6, TNF-α, and PGE2) for their ability to counteract Tregs on different levels.

Characterization of CD8+ T-cell responses in the peripheral blood and skin injection sites of melanoma patients treated with mRNA electroporated autologous dendritic cells (TriMixDC-MEL).

Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL) stimulates T-cell responses against the presented tumor-associated antigens (TAAs). In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8(+) T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs) and within the circulation of melanoma patients treated in two clinical trials.

Dendritic cells loaded with mRNA encoding full-length tumor antigens prime CD4+ and CD8+ T cells in melanoma patients.

It is generally thought that dendritic cells (DCs) loaded with full-length tumor antigen could improve immunotherapy by stimulating broad T-cell responses and by allowing treatment irrespective of the patient's human leukocyte antigen (HLA) type. To investigate this, we determined the specificity of T cells from melanoma patients treated with DCs loaded with mRNA encoding a full-length tumor antigen fused to a signal peptide and an HLA class II sorting signal, allowing presentation in HLA class I and II. In delayed-type hypersensitive (DTH)-biopsies and blood, we found functional CD8(+) and CD4(+) T cells recognizing novel treatment-antigen-derived epitopes, presented by several HLA types.

Epitope and HLA-type independent monitoring of antigen-specific T-cells after treatment with dendritic cells presenting full-length tumor antigens.

The efficacy of cancer immunotherapy can be improved by treatment with full-length tumor antigen and by combining several antigens. This approach allows the induction of a broad immune response irrespective of the patient's HLA type which at the same time challenges immune monitoring. Also, the number of available lymphocytes is most often limited and minimal in vitro restimulations of the lymphocytes should maintain information about the actual in vivo situation.

A phase I/IIa immunotherapy trial of HIV-1-infected patients with Tat, Rev and Nef expressing dendritic cells followed by treatment interruption.

In a phase I/IIa clinical trial, 17 HIV-1 infected patients, stable on cART, received 4 vaccinations with autologous dendritic cells electroporated with mRNA encoding Tat, Rev and Nef, after which cART was interrupted. Vaccination was safe and feasible. During the analytical treatment interruption (ATI), no serious adverse events were observed.

Intravenous and intradermal TriMix-dendritic cell therapy results in a broad T-cell response and durable tumor response in a chemorefractory stage IV-M1c melanoma patient.

Dendritic cells (DCs) electroporated with mRNA encoding CD70, CD40L and a constitutively active toll-like receptor 4 (TriMix-DC) have an increased T-cell stimulatory capacity. In a prospective phase IB clinical trial, we treated melanoma patients with intradermal and intravenous injections of autologous TriMix-DC co-electroporated with mRNA encoding full-length MAGE-A3, MAGE-C2, tyrosinase and gp100. We report here the immunological and clinical results obtained in one patient with a particularly favorable outcome.

Therapeutic vaccination with an autologous mRNA electroporated dendritic cell vaccine in patients with advanced melanoma.

The immunostimulatory capacity of dendritic cells is improved by co-electroporation with mRNA encoding CD40 ligand, constitutively active toll-like receptor 4, and CD70 (TriMix-DC). This pilot clinical trial evaluated the feasibility, safety, and immunogenicity of a therapeutic vaccination containing autologous TriMix-DC co-electroporated with mRNA encoding a human leukocyte antigen class II-targeting signal linked to 1 of 4 melanoma-associated antigens (MAGE-A3, MAGE-C2, tyrosinase, and gp100) in patients with advanced melanoma. Thirty-five American Joint Committee on Cancer stage III/IV melanoma patients received autologous TriMix-DC (4 administrations 2 weeks apart).

The combination of 4-1BBL and CD40L strongly enhances the capacity of dendritic cells to stimulate HIV-specific T cell responses.

One of the consequences of HIV infection is a progressive loss of T cell functions, resulting in decreased cytokine secretion and proliferation and an increased sensitivity to apoptosis. Therefore, successful therapeutic vaccination approaches should aim at restoring the functionality of existing HIV-specific T cells, as well as to efficiently induce potent, HIV-specific T cells from naïve T cells. In this study, we wanted to determine the stimulatory capacity of DCs coelectroporated with mRNA encoding for different costimulatory molecules of the TNFSF, together with HIV antigen-encoding mRNA.

Restoration of tumor equilibrium after immunotherapy for advanced melanoma: three illustrative cases.

Metastatic melanoma runs a predictable detrimental course in the vast majority of patients. New modalities of immunotherapy, such as melanoma antigen-specific therapeutic vaccination and cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptor blockade by monoclonal antibodies (mAbs), have been associated with atypical kinetics of tumor response that differ from those observed during cytotoxic treatment. Recently, new tumor response criteria have been proposed based on the tumor response characteristics observed in clinical studies with ipilimumab (the so-called 'immune-related response criteria').

Immunotherapy of cancer with dendritic cells loaded with tumor antigens and activated through mRNA electroporation.

Since decades, the main goal of tumor immunologists has been to increase the capacity of the immune system to mediate tumor regression. Considerable progress has been made in enhancing the efficacy of therapeutic anticancer vaccines. First, dendritic cells (DCs) have been identified as the key players in orchestrating primary immune responses.

Lumenal part of the DC-LAMP protein is not required for induction of antigen-specific T cell responses by means of antigen-DC-LAMP messenger RNA-electroporated dendritic cells.

Previous studies showed that stimulation of T cells derived from HIV-1-infected patients with autologous dendritic cells electroporated with mRNA encoding HIV antigens can induce antigen-specific T cell responses in vitro. Linking the antigen to an MHC class II-targeting sequence, such as dendritic cell lysosome-associated membrane protein (DC-LAMP), in the mRNA construct results in presentation of antigenic peptides in both MHC class I and class II molecules and therefore enhances the induced T cell responses. To analyze whether the lumenal domain of DC-LAMP is required for optimal induction of cellular immunity against HIV antigens, we compared fusion constructs with or without the lumenal domain of the DC-LAMP protein.