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607 Background: To date, no biomarker of efficacy of nivolumab+/-ipilimumab (N+/-I) or anti-VEGFR TKI has been prospectively validated in mRCC. The BIONIKK trial showed promising objective response rate (ORR) and progression-free survival (PFS) with these treatments in first line (L1) after selection by tumour molecular group. We report OS and efficacy results of the second-line (L2) treatment. Methods: BIONIKK is a French multicentre non-comparative phase II trial, randomising 199 mRCC pts to receive N (58), NI (101) or TKI (40) in L1 according to four molecular groups (ccrcc1-4). ORR and PFS were already reported. With an additional follow-up of ≥20 months, we report OS from randomization and from the start of L2, as well as ORR and PFS with a TKI in L2 by molecular group. Results: With a median follow-up of 42.1 months (40.5-45.2), 86 (43%) patients died: 27/58 (46.5%), 39/101 (39%) and 20/40 (50%) in the N, NI, and TKI arm, respectively. Median OS were 43.4 months (95%CI=31.4-NR) with N, 52.7 months (95%CI=46-NR) with NI and 38.1 months (95%CI=33.2-NR) with TKI (table). 175 (88%) patients discontinued first-line treatment, including 20 deaths, and 129 (74%) received a L2, 38/58 (65.5%), 64/101 (63%), and 27/40 (67.5%) after N, NI and TKI, respectively. The most frequent L2 received after N+/-I was a TKI in 96/102 (94%) pts, including cabozantinib in 49, sunitinib/pazopanib in 32, axitinib in 13, and lenvatinib in 2. N was the most frequent L2 after TKI, 20/27 (74%). ORR with TKI in L2 was 28.5% (10/35) after N, 39% (24/61) after NI and 80% (4/5) after TKI, with marked benefit in ccrcc2 pts (table). The mPFS with TKI in L2 was 8.2 (95%CI=6.9-19.3) after N, 11.4 (95%CI= 8.9-16.8) after NI, and 12.1 (95%CI =11.4-NR) months after TKI, with a higher benefit in ccrcc2 pts (vs. ccrcc1+4, p=0.04). Conversely, ORR and mPFS with N after TKI in ccrcc2-pts were 12.5% (2/16) and 5.4 (2.6-NR) months, respectively. Median OS L2 was reported in the table. The updated ORR and PFS in L1 will presented at the Meeting, as well as PFS2 and efficacy by TKI type in L2. Conclusions: We report for the first-time OS and L2 efficacy results by molecular group in a randomized trial. Molecular selection also has an impact on treatment efficacy in L2. These results, together with those reported in L1, can inform clinicians on the best treatment sequence in L1-2. Clinical trial information: NCT02960906 . [Table: see text]

2511 Background: While ICB has significantly improved clinical outcomes across several cancer types, only 15-20% of patients develop a durable response. Thus, novel and targetable biomarkers are needed. There is increased appreciation of the role of the gut microbiome, and TLS and B-cells in the TME in response to ICB. Here, we investigate the association between these two determinants of response in patient specimens from three randomized phase 2 neoadjuvant ICB trials of nivolumab +/- ipilimumab (melanoma (MEL; NCT02519322; n=23), non-small-cell lung cancer (NSCLC; NCT03158129; n=31), sarcoma (SARC; NCT02301039; n=17). Methods: Patients were categorized as responders (R) or non-responders (NR) based on major pathologic response, as defined in each histotype (MEL and NSCLC viable tumor ≤10%; SARC hyalinization>30%). Baseline fecal samples were profiled via 16S rRNA gene sequencing from all three cohorts to assess the composition of patient gut microbiomes. Transcriptional profiles of biopsies collected pre-ICB for MEL and SARC, and post-ICB for MEL, SARC, and NSCLC were used to assess TLS (CXCL13, CCL18, CCL19, CCL21) and B-cell (PAX5, CD79B, CR2, MS4A1) signatures in the TME, by calculated mean values of normalized gene expressions. Comparison between samples were carried out using the Wilcoxon signed-rank test. Results: There were 21 R overall (NSCLC n=9; MEL n=9; SARC n=3). Despite significant differences in alpha and beta diversity across cohorts, relative abundance of Ruminococcus was significantly higher in R (p=0.003; NSCLC p

BackgroundThe immunological microenvironment of primary high-grade serous carcinomas (HGSCs) has a major impact on disease outcome. Conversely, little is known on the microenvironment of metastatic HGSCs and its potential influence on patient survival. Here, we explore the clinical relevance of the immunological configuration of HGSC metastases.MethodsRNA sequencing was employed on 24 paired primary tumor microenvironment (P-TME) and metastatic tumor microenvironment (M-TME) chemotherapy-naive HGSC samples. Immunohistochemistry was used to evaluate infiltration by CD8+ T cells, CD20+ B cells, DC-LAMP+ (lysosomal-associated membrane protein 3) dendritic cells (DCs), NKp46+ (natural killer) cells and CD68+CD163+ M2-like tumor-associated macrophages (TAMs), abundance of PD-1+ (programmed cell death 1), LAG-3+ (lymphocyte-activating gene 3) cells, and PD-L1 (programmed death ligand 1) expression in 80 samples. Flow cytometry was used for functional assessments on freshly resected HGSC samples.Results1468 genes were differentially expressed in the P-TME versus M-TME of HGSCs, the latter displaying signatures of extracellular matrix remodeling and immune infiltration. M-TME infiltration by immune effector cells had little impact on patient survival. Accordingly, M-TME-infiltrating T cells were functionally impaired, but not upon checkpoint activation. Conversely, cytokine signaling in favor of M2-like TAMs activity appeared to underlie inhibited immunity in the M-TME and poor disease outcome.ConclusionsImmunosuppressive M2-like TAM infiltrating metastatic sites limit clinically relevant immune responses against HGSCs.

Renal cell carcinoma (RCC) encompasses a wide spectrum of morphologically and molecularly distinct (>10) cancer subtypes originated from the kidney epithelium. Metastatic RCC (mRCC) is lethal and refractory to conventional chemotherapeutic agents. The incorporation of targeted therapies and immune checkpoint inhibitors into the current practice of mRCC has markedly improved the median overall survival of clear cell RCC (ccRCC) patients, the most common subtype, but not rare kidney cancer (RKC or non-ccRCC, nccRCC). Varied treatment response in mRCC patients is observed, which presents clinical challenges/opportunities at the modern mRCC therapeutic landscape consisting of 12 approved drugs representing 6 different effective mechanisms. Key contributing factors include inter- and intra-RCC heterogeneity. With the advances in pan-omics technologies, we now have a better understanding of the molecular pathobiology of individual RCC subtype. Here, we attempt to classify ccRCC based on contemporary molecular features with emphasis on their respective potential significance in clinical practice.

Resume Nee a l’aube du XX e siecle avec les injections intratumorales de bacteries par W.B. Coley, l’immunotherapie s’est constituee sur le corpus des theories de la surveillance immunitaire en 1957, modifie par R.D. Schreiber en 2004. Les avancees des connaissances et des technologies ont permis son efficacite et son expansion au XXI e siecle ou elle s’impose comme le 4 e et le plus important pilier du traitement des cancers.

INTRODUCTION: Recent trials have suggested predictive biomarkers in advanced clear-cell renal cell carcinoma (accRCC): International Metastatic RCC Database Consortium (IMDC) good risk or angiogenic gene signature for sunitinib and IMDC intermediate/poor risk for ipilimumab-nivolumab and T-effector cell signature or sarcomatoid dedifferentiation for atezolizumab-bevacizumab. We hypothesized that earlier described molecular subtypes, ccrcc1 to ccrcc4, could provide similar information as a single generic biomarker and molecularly characterize the heterogeneous intermediate-risk group. PATIENTS AND METHODS: Patients with accRCC treated with systemic therapies were included. We assessed associations between the 5 biomarkers and their impact on progression-free survival (PFS) and response rate (RR) on first-line sunitinib or pazopanib. The cutoff percentage of sarcomatoid dedifferentiation with optimal discriminative value was determined. RESULTS: In total, 430 patients were included (163 with molecular data). The molecular ccrcc2 subtype identified tumors with higher angiogenic gene expression across IMDC risk groups: prevalence was high in IMDC good risk and low in IMDC poor risk (P < .001). Molecular subtype, IMDC, and angiogenic gene expression had comparable C-indices to predict PFS and RR (range, 60%-66%). The ccrcc2 subtype and angiogenic gene expression were positive predictors of PFS in IMDC intermediate-risk patients (P = .006; P = .04). Immune signature did not differ between IMDC groups, but was strongly correlated with molecular subtype (P = .8 and P = .0007). A cutoff value of 25% sarcomatoid differentiation discriminated tumors with distinct molecular characteristics and therapeutic sensitivity. CONCLUSION: In accRCC, molecular subtypes can explain differences in IMDC risk group, expression of angiogenesis and immune response genes, and sarcomatoid dedifferentiation. They can identify molecularly different patient populations within the heterogeneous IMDC intermediate group and select patients for systemic therapies. ispartof: CLINICAL GENITOURINARY CANCER vol:17 issue:5 pages:E981-E994 ispartof: location:United States status: published

Stimuler le systeme immunitaire des patients pour les aider a controler, voire rejeter, les cancers dont ils sont atteints est un concept ancien qui a recemment connu des developpements spectaculaires couronnes par l’attribution du Prix Nobel de medecine et de physiologie a James P. Allison et Tatsuku Honjo en 2018.L’immunotherapie est devenue le quatrieme pilier des therapies anti-cancereuses, avec des autorisations de mises sur le marche de medicaments immunomodulateurs attribuees a un rythme eleve (plus d’une par mois).L’immunotherapie a pour vocation de traiter tous les cancers, quels que soient leurs types histologiques ; mais elle se heurte deja a des defis importants comme la resistance primaire et acquise d’un grand nombre de tumeurs, la toxicite liee a l’hyperstimulation du systeme immunitaire et le cout quelquefois exorbitant de certaines immunotherapies.

Background The NIVOREN GETUG-AFU 26 study reported safety and efficacy of N in mccRCC pts in a “real world setting”. A translationnal research program was launched to characterize immune cell populations in and around the tumor by immunohistochemistry (IHC) and correlate them with outcome on N. Methods All pts treated with N in the GETUG AFU 26 NIVOREN trial who consented for translational program and with available archived paraffin-embedded (FFPE) tumor tissue samples were eligible. Tumor were centrally reviewed. Densities of CD3-, CD8- and CD20-cells and tertiary lymphoid structures (TLS) were estimated by IHC. PD-L1 expression was quantified as percentage of positive tumor cells (TC) and immune cells (IC). Results Overall 324 pts were included. Pts had similar baseline characteristics (IMDC Good, Intermediate, Poor in 18%, 60% and 22%, respectively) than overall trial population. Median PFS was 4.5 (2.9-5.2) months and median OS 25.4 (23.6-NE) months. Highest density of CD8 T cells at the invasive margin (IM) was associated with worse PFS (2.3 vs 4.6 months, HR = 3.96 (1.84-8.51), p = 0.0001) and OS (8.6 vs 25.4 months, HR = 2.43 (0.99-5.95), p = 0.0451). PD-L1 expression on TC (³1%) was associated with worse OS (22.7 vs 29.1 months, HR = 1.51 (1.06-2.15), p = 0.0232) but not PFS (3.5 vs 4.6 months, p = 0.5121). PD-L1 expression on IC (³1%) was associated with numerically shorter median OS (24.7 months vs NR, HR = 1.34 (0.95-1.88), p = 0.0955). CD8 densities, either in the T or at the IM were associated with high PD-L1 expression (>1%) by TC or by IC (all p Conclusions We report the largest translational analysis supporting that highest CD8 density at the IM is associated with worse OS and PFS while PD-L1 expression by ³1% TC or IC is associated with worse OS in pts with mccRCC receiving N. Clinical trial identification NCT03013335. Legal entity responsible for the study UNICANCER. Funding Institut National du Cancer, Direction Generale de l’Offre de Soins, Bristol-Myers-Squibb. Disclosure Y. Vano: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy: Ipsen; Honoraria (self), Advisory / Consultancy: Pfizer; Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy: Merck; Travel / Accommodation / Expenses: Janssen-Cilag; Honoraria (self), Advisory / Consultancy: Sanofi; Honoraria (self), Advisory / Consultancy: Astellas. N. Rioux-Leclercq: Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: Janssen-Cilag; Honoraria (self), Advisory / Consultancy: Ipsen. B. Beuselinck: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): BMS. M. Gross-Goupil: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: MSD; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Ipsen; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: GSK. S. Negrier: Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy: Ipsen; Honoraria (self), Advisory / Consultancy: Eusa Pharma. D. Borchiellini: Honoraria (self), Advisory / Consultancy: BMS; Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: Ipsen; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Roche; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): MSD; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Janssen-Cilag; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Astellas; Honoraria (self), Advisory / Consultancy: Sanofi. B. Escudier: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Pfizer; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy: Ipsen; Honoraria (self), Advisory / Consultancy: Eusa Pharma; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Aveo. L. Albiges: Honoraria (institution), Advisory / Consultancy: Pfizer; Honoraria (institution), Advisory / Consultancy: BMS; Honoraria (institution), Advisory / Consultancy: Ipsen; Honoraria (institution), Advisory / Consultancy: Roche; Honoraria (institution), Advisory / Consultancy: MSD; Honoraria (institution), Advisory / Consultancy: AstraZeneca; Honoraria (institution), Advisory / Consultancy: Novartis. All other authors have declared no conflicts of interest.

Soft tissue sarcoma (STS) are rare mesenchymal-originated tumors with more than 50 different histologies identified. Not every histology in STS responds to immunotherapy and immunologic predictive markers are lacking. The purpose of this study is to establish an immune classification of STS by analysis of the transcriptome. This was performed by using a deconvolution method that allowed us to quantify 8 immune populations and endothelial cells. As a secondary objective, we searched for a surrogate biomarker that could be assessable in the clinic. We analyzed transcriptomic data of four publicly available datasets, accounting for 608 complex genomic STS, including leiomyosarcoma (LMS, 35.4%), dedifferentiated liposarcoma (DDLPS, 33.9%) and undifferentiated pleomorphic sarcoma (UPS, 30.8%). By using the MCP-Counter deconvolution method, we characterized the tumor microenvironment (TME) of these tumors and established a robust immune classification that is consistent through various cohorts. We classified the patients into 5 Sarcoma Immune Classes (SIC), labeled as A1, A2, B, C1 and C2. The A1 and A2 groups are associated with very low to low immune infiltrates. Conversely, SIC C1 and C2 tumors are characterized by strong to very strong expression of signatures associated to all immune cells. SIC B tumors are characterized by a high expression of endothelial cell signature, an intermediate presence of neutrophils, and a rather low infiltration by other immune cell types. Regarding functional orientation of the TME, gene signatures associated with immune cells chemotaxis activation and survival, expression of major histocompatibility complex class I, and regulatory T-cells are highly expressed in SIC C1 and C2, modestly expressed in B and A2, and very lowly expressed in A1. Interestingly, immune checkpoint genes exhibited strong expression differences between SICs. SIC C2 had a strong expression of PD-1, PD-L2, CTLA-4 and TIM-3 genes. We also found that the lymphoid structure-associated B cell chemoattractant chemokine CXCL13 is remarkably highly expressed in C2 class. CXCL13 is associated with the presence of tertiary lymphoid structures (TLS). Although all histologies are distributed in each SIC group, LMS are more commonly found in the immune low SIC A1 and A2 groups, and we also extended our analysis to other histologies such as synovial sarcoma or gastrointestinal stromal tumors. Our classification is associated with clinical outcome, and SIC group C (C1/C2) has the longest overall survival, as compared to SIC A group (A1/A2) (p = 0.015). We then validated SIC classification using STS FFPE samples (n=32). SIC classification by RNA expression was correlated with quantitative immunohistochemistry (IHC) of CD3 (T-cells), DC-Lamp (activated dendritic cells), CD20 (B cells), CD8 (CD8+ T-cells), and CD34 (endothelial cells). Densities of CD3 (p=0.0033), CD8 (p=0.004) and CD20 (p=0.00043) were significantly higher in SIC C tumors. Tumor SIC B groups have a higher, albeit nonsignificant (p=0.6) expression of CD34+ endothelial cells. In the validation cohort, SIC group C is associated with a better prognosis (p=0.053). We further investigated whether TLS were a marker of the immune-high SIC C group. Not surprisingly, TLS-positive tumors were found only in SIC C2 (100%, 9/9) and C1 (50%, 3/6) groups of the validation cohort. We expanded the validation cohort (n = 93) to analyze the correlation between TLS and CD3+/CD8+/CD20+ tumor-infiltrating lymphocytes. We found that the presences of each type of TILs all are significantly associated with the presence of TLS (CD3, CD8, CD20, all p values < 0.0001). This validation finding suggests that TLS may be a good surrogate marker for identification of SIC C groups and could be validated in the future to correlate with the efficacy of immunotherapy in STS. Citation Format: Wei-Wu Tom Chen, Florent Petitprez, Cheng-Ming Sun, Laetitia Lacroix, Aurélien de Reyniès, Antoine Italiano, Maud Toulmonde, Carlo Lucchesi, Yec'han Laizet, Catherine Sautès-Fridman, Wolf Herve Fridman. Immune-based classification of soft-tissue sarcoma is associated with clinical outcome and unveils tertiary lymphoid structures as surrogate biomarker for the clinic [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr PR03.

Natural killer (NK) cells express a set of activating and inhibitory receptors which, after interaction with their ligands, determine whether or not the target cell will be lysed. Many studies have clearly demonstrated that NK cells have the capacity to lyse stressed cells (such as tumor or virally-infected cells). However, NK cells that infiltrate tumors usually exhibit phenotypic and functional defects. In this issue of the European Journal of Immunology, Vacca et al. [Eur. J. Immunol. 2013. 43: 550‒561] show that NK cells in pleural effusions of primary and metastatic tumors of various origins are not anergic, possibly because the downregulation of activating receptors and the upregulation of inhibitory receptors does not occur, as previously reported for tumor NK cells. Another major finding of this study is the capacity of these pleural NK cells to respond to IL-2 stimulation, as the authors demonstrate that pleural NK cells stimulated by IL-2 in long-term culture acquire the capacity to lyse autologous tumor cells isolated from pleural effusions. These results support the treatment of primary or metastatic pleural tumors with IL-2 or other innovative strategies currently being developed to stimulate NK cells in cancer patients as discussed in this Commentary.

Prophylactic vaccination constitutes one of the most prominent medical achievements of history. This concept was first demonstrated by the pioneer work of Edward Jenner, dating back to the late 1790s, after which an array of preparations that confer life-long protective immunity against several infectious agents has been developed. The ensuing implementation of nation-wide vaccination programs has de facto abated the incidence of dreadful diseases including rabies, typhoid, cholera and many others. Among all, the most impressive result of vaccination campaigns is surely represented by the eradication of natural smallpox infection, which was definitively certified by the WHO in 1980. The idea of employing vaccines as anticancer interventions was first theorized in the 1890s by Paul Ehrlich and William Coley. However, it soon became clear that while vaccination could be efficiently employed as a preventive measure against infectious agents, anticancer vaccines would have to (1) operate as therapeutic, rather than preventive, interventions (at least in the vast majority of settings), and (2) circumvent the fact that tumor cells often fail to elicit immune responses. During the past 30 y, along with the recognition that the immune system is not irresponsive to tumors (as it was initially thought) and that malignant cells express tumor-associated antigens whereby they can be discriminated from normal cells, considerable efforts have been dedicated to the development of anticancer vaccines. Some of these approaches, encompassing cell-based, DNA-based and purified component-based preparations, have already been shown to exert conspicuous anticancer effects in cohorts of patients affected by both hematological and solid malignancies. In this Trial Watch, we will summarize the results of recent clinical trials that have evaluated/are evaluating purified peptides or full-length proteins as therapeutic interventions against cancer.

Solid tumors are constituted of a variety of cellular components, including bona fide malignant cells as well as endothelial, structural and immune cells. On one hand, the tumor stroma exerts major pro-tumorigenic and immunosuppressive functions, reflecting the capacity of cancer cells to shape the microenvironment to satisfy their own metabolic and immunological needs. On the other hand, there is a component of tumor-infiltrating leucocytes (TILs) that has been specifically recruited in the attempt to control tumor growth. Along with the recognition of the critical role played by the immune system in oncogenesis, tumor progression and response to therapy, increasing attention has been attracted by the potential prognostic and/or predictive role of the immune infiltrate in this setting. Data from large clinical studies demonstrate indeed that a robust infiltration of neoplastic lesions by specific immune cell populations, including (but not limited to) CD8+ cytotoxic T lymphocytes, Th1 and Th17 CD4+ T cells, natural killer cells, dendritic cells, and M1 macrophages constitutes an independent prognostic indicator in several types of cancer. Conversely, high levels of intratumoral CD4+CD25+FOXP3+ regulatory T cells, Th2 CD4+ T cells, myeloid-derived suppressor cells, M2 macrophages and neutrophils have frequently been associated with dismal prognosis. So far, only a few studies have addressed the true predictive potential of TILs in cancer patients, generally comforting the notion that—at least in some clinical settings—the immune infiltrate can reliably predict if a specific patient will respond to therapy or not. In this Trial Watch, we will summarize the results of clinical trials that have evaluated/are evaluating the prognostic and predictive value of the immune infiltrate in the context of solid malignancies.

Malignant cells succumbing to some forms of radiation therapy are particularly immunogenic and hence can initiate a therapeutically relevant adaptive immune response. This reflects the intrinsic antigenicity of malignant cells (which often synthesize a high number of potentially reactive neo-antigens) coupled with the ability of radiation therapy to boost the adjuvanticity of cell death as it stimulates the release of endogenous adjuvants from dying cells. Thus, radiation therapy has been intensively investigated for its capacity to improve the therapeutic profile of several anticancer immunotherapies, including (but not limited to) checkpoint blockers, anticancer vaccines, oncolytic viruses, Toll-like receptor (TLR) agonists, cytokines, and several small molecules with immunostimulatory effects. Here, we summarize recent preclinical and clinical advances in this field of investigation.

Toll-like receptors (TLRs) are prototypic pattern recognition receptors (PRRs) best known for their ability to activate the innate immune system in response to conserved microbial components such as lipopolysaccharide and double-stranded RNA. Accumulating evidence indicates that the function of TLRs is not restricted to the elicitation of innate immune responses against invading pathogens. TLRs have indeed been shown to participate in tissue repair and injury-induced regeneration as well as in adaptive immune responses against cancer. In particular, TLR4 signaling appears to be required for the efficient processing and cross-presentation of cell-associated tumor antigens by dendritic cells, which de facto underlie optimal therapeutic responses to some anticancer drugs. Thus, TLRs constitute prominent therapeutic targets for the activation/intensification of anticancer immune responses. In line with this notion, long-used preparations such as the Coley toxin (a mixture of killed Streptococcus pyogenes and Serratia marcescens bacteria) and the bacillus Calmette-Guerin (BCG, an attenuated strain of Mycobacterium bovis originally developed as a vaccine against tuberculosis), both of which have been associated with consistent anticancer responses, potently activate TLR2 and TLR4 signaling. Today, besides BCG, only one TLR agonist is FDA-approved for therapeutic use in cancer patients: imiquimod. In this Trial Watch, we will briefly present the role of TLRs in innate and cognate immunity and discuss the progress of clinical studies evaluating the safety and efficacy of experimental TLR agonists as immunostimulatory agents for oncological indications.

During the last two decades, several approaches for the activation of the immune system against cancer have been developed. These include rather unselective maneuvers such as the systemic administration of immunostimulatory agents (e.g., interleukin-2) as well as targeted interventions, encompassing highly specific monoclonal antibodies, vaccines and cell-based therapies. Among the latter, adoptive cell transfer (ACT) involves the selection of autologous lymphocytes with antitumor activity, their expansion/activation ex vivo, and their reinfusion into the patient, often in the context of lymphodepleting regimens (to minimize endogenous immunosuppression). Such autologous cells can be isolated from tumor-infiltrating lymphocytes or generated by manipulating circulating lymphocytes for the expression of tumor-specific T-cell receptors. In addition, autologous lymphocytes can be genetically engineered to prolong their in vivo persistence, to boost antitumor responses and/or to minimize side effects. ACT has recently been shown to be associated with a consistent rate of durable regressions in melanoma and renal cell carcinoma patients and holds great promises in several other oncological settings. In this Trial Watch, we will briefly review the scientific rationale behind ACT and discuss the progress of recent clinical trials evaluating the safety and effectiveness of adoptive cell transfer as an anticancer therapy.

Since the advent of hybridoma technology, dating back to 1975, monoclonal antibodies have become an irreplaceable diagnostic and therapeutic tool for a wide array of human diseases. During the last 15 years, several monoclonal antibodies (mAbs) have been approved by FDA for cancer therapy. These mAbs are designed to (1) activate the immune system against tumor cells, (2) inhibit cancer cell-intrinsic signaling pathways, (3) bring toxins in the close proximity of cancer cells, or (4) interfere with the tumor-stroma interaction. More recently, major efforts have been made for the development of immunostimulatory mAbs that either enhance cancer-directed immune responses or limit tumor- (or therapy-) driven immunosuppression. Some of these antibodies, which are thought to facilitate tumor eradication by initiating or sustaining a tumor-specific immune response, have already entered clinical trials. In this Trial Watch, we will review and discuss the clinical progress of the most important mAbs that are have entered clinical trials after January 2008.

During the past decade, great efforts have been dedicated to the development of clinically relevant interventions that would trigger potent (and hence potentially curative) anticancer immune responses. Indeed, developing neoplasms normally establish local and systemic immunosuppressive networks that inhibit tumor-targeting immune effector cells, be them natural or elicited by (immuno)therapy. One possible approach to boost anticancer immunity consists in the (generally systemic) administration of recombinant immunostimulatory cytokines. In a limited number of oncological indications, immunostimulatory cytokines mediate clinical activity as standalone immunotherapeutic interventions. Most often, however, immunostimulatory cytokines are employed as immunological adjuvants, i.e., to unleash the immunogenic potential of other immunotherapeutic agents, like tumor-targeting vaccines and checkpoint blockers. Here, we discuss recent preclinical and clinical advances in the use of some cytokines as immunostimulatory agents in oncological indications.

Objective— Studies suggest the implication of CD16 + subpopulations (CD14 + CD16 + , CD14 dim CD16 + ) in inflammatory diseases. We aimed to determine the frequency of these subpopulations during weight loss in obesity and diabetes, conditions associated with changes in systemic inflammation, and we tested the link with subclinical atherosclerosis. Methods and Results— CD14 dim CD16 + and CD14 + CD16 + frequencies were measured by flow cytometry in lean subjects, obese subjects before and after a hypocaloric diet or gastric surgery, and obese diabetic subjects before and after gastric surgery. Both monocyte subsets were increased in obese subjects, with a significant enrichment of the CD14 dim CD16 + subpopulation in obese diabetic patients. Multivariate analysis demonstrated a link between the percentages of CD14 dim CD16 + monocytes and glycemia, independent of fat mass. Drastic weight loss led to a sharp decrease of this subset, the variations of which were strongly related to fat mass changes. A reduction of at least 5% of fat mass was sufficient to observe a significant decrease of CD14 dim CD16 + monocytes. A diminution of the CD14 + CD16 + subset was also observed during weight loss and was associated with a decrease in intima-media thickness. Conclusion— This work demonstrates a major impact of fat mass variations on CD14 dim CD16 + monocyte subsets and that the decrease in the CD14 + CD16 + subpopulation is linked to a reduction of subclinical atherosclerosis. Clinical Trial Registration— URL: http://clinicaltrials.gov . Unique identifier: NCT00476658.

Accumulating preclinical evidence indicates that Toll-like receptor (TLR) agonists efficiently boost tumor-targeting immune responses (re)initiated by most, if not all, paradigms of anticancer immunotherapy. Moreover, TLR agonists have been successfully employed to ameliorate the efficacy of various chemotherapeutics and targeted anticancer agents, at least in rodent tumor models. So far, only three TLR agonists have been approved by regulatory agencies for use in cancer patients. Moreover, over the past decade, the interest of scientists and clinicians in these immunostimulatory agents has been fluctuating. Here, we summarize recent advances in the preclinical and clinical development of TLR agonists for cancer therapy.

A high density of tumor-infiltrating mature dendritic cells (DC) and CD8+ T cells correlates with a positive prognosis in a majority of human cancers. The recruitment of activated lymphocytes to the tumor microenvironment, primed to recognize tumor-associated antigens, can occur in response to immunogenic cell death (ICD) of tumor cells. ICD is characterized by the preapoptotic translocation of calreticulin (CRT) from the endoplasmic reticulum (ER) to the cell surface as a result of an ER stress response accompanied by the phosphorylation of eukaryotic initiation factor 2α (eIF2α). We conducted a retrospective study on two independent cohorts of patients with non–small cell lung cancer (NSCLC) to investigate the prognostic potential of CRT. We report that the level of CRT expression on tumor cells, which correlated with eIF2α phosphorylation, positively influenced the clinical outcome of NSCLC. High CRT expression on tumor cells was associated with a higher density of infiltrating mature DC and effector memory T-cell subsets, suggesting that CRT triggers the activation of adaptive immune responses in the tumor microenvironment. Accordingly, patients with elevated CRT expression and dense intratumoral infiltration by DC or CD8+ T lymphocytes had the best prognosis. We conclude that CRT expression constitutes a new powerful prognostic biomarker that reflects enhanced local antitumor immune responses in the lung. Cancer Res; 76(7); 1746–56. ©2016 AACR.

Purpose: The human telomerase reverse transcriptase (hTERT) is considered as a potential target for cancer immunotherapy because it is preferentially expressed in tumor cells. To increase the applicability of hTERT-based immunotherapy, we set out to identify CTL epitopes in hTERT restricted by HLA-B*0702 molecule, a common MHC class I allele.Experimental Design: HLA-B*0702-restricted peptides from hTERT were selected by using a method of epitope prediction and tested for their immunogenicity in human (in vitro) and HLA-B*0702 transgenic mice (in vivo).Results: All the six hTERT peptides that were predicted to bind to HLA-B*0702 molecule were found to induce primary human CTL responses in vitro. The peptide-specific CD8+ CTL lines were tested against various hTERT+ tumor cells. Although differences were observed according to the tumor origin, only three CTL lines specific for p277, p342, and p351 peptides exhibited cytotoxicity against tumor cells in a HLA-B*0702-restricted manner. In addition, this cytotoxicity was inhibited by the addition of peptide-loaded cold target cells and indicated that these epitopes are naturally processed and presented on the tumor cells. Further, in vivo studies using humanized HLA-B*0702 transgenic mice showed that all the candidate peptides were able to induce CTL responses after peptide immunization. Furthermore, vaccination with a plasmid DNA encoding full-length hTERT elicited peptide-specific CTL responses, indicating that these epitopes are efficiently processed in vivo.Conclusions: Together with previously reported hTERT epitopes, the identification of new CTL epitopes presented by HLA-B*0702 increases the applicability of hTERT-based immunotherapy to treating cancer.

The use of patient-derived dendritic cells (DCs) as a means to elicit therapeutically relevant immune responses in cancer patients has been extensively investigated throughout the past decade. In this context, DCs are generally expanded, exposed to autologous tumor cell lysates or loaded with specific tumor-associated antigens (TAAs), and then reintroduced into patients, often in combination with one or more immunostimulatory agents. As an alternative, TAAs are targeted to DCs in vivo by means of monoclonal antibodies, carbohydrate moieties or viral vectors specific for DC receptors. All these approaches have been shown to (re)activate tumor-specific immune responses in mice, often mediating robust therapeutic effects. In 2010, the first DC-based preparation (sipuleucel-T, also known as Provenge®) has been approved by the US Food and Drug Administration (FDA) for use in humans. Reflecting the central position occupied by DCs in the regulation of immunological tolerance and adaptive immunity, the interest in harnessing them for the development of novel immunotherapeutic anticancer regimens remains high. Here, we summarize recent advances in the preclinical and clinical development of DC-based anticancer therapeutics.

An expanding panel of monoclonal antibodies (mAbs) that specifically target malignant cells or intercept trophic factors delivered by the tumor stroma is now available for cancer therapy. These mAbs can exert direct antiproliferative/cytotoxic effects as they inhibit pro-survival signal transduction cascades or activate lethal receptors at the plasma membrane of cancer cells, they can opsonize neoplastic cells to initiate a tumor-targeting immune response, or they can be harnessed to specifically deliver toxins or radionuclides to transformed cells. As an indication of the success of this immunotherapeutic paradigm, international regulatory agencies approve new tumor-targeting mAbs for use in cancer patients every year. Moreover, the list of indications for previously licensed molecules is frequently expanded to other neoplastic disorders as the results of large, randomized clinical trials become available. Here, we discuss recent advances in the preclinical and clinical development of tumor-targeting mAbs for oncological indications.

During the past 2 decades, the possibility that preparations capable of eliciting tumor-specific immune responses would mediate robust therapeutic effects in cancer patients has received renovated interest. In this context, several approaches to vaccinate cancer patients against their own malignancies have been conceived, including the administration of DNA constructs coding for one or more tumor-associated antigens (TAAs). Such DNA-based vaccines conceptually differ from other types of gene therapy in that they are not devised to directly kill cancer cells or sensitize them to the cytotoxic activity of a drug, but rather to elicit a tumor-specific immune response. In spite of an intense wave of preclinical development, the introduction of this immunotherapeutic paradigm into the clinical practice is facing difficulties. Indeed, while most DNA-based anticancer vaccines are well tolerated by cancer patients, they often fail to generate therapeutically relevant clinical responses. In this Trial Watch, we discuss the latest advances on the use of DNA-based vaccines in cancer therapy, discussing the literature that has been produced around this topic during the last 13 months as well as clinical studies that have been launched in the same time frame to assess the actual therapeutic potential of this intervention.

Accumulating evidence suggests that the clinical efficacy of selected anticancer drugs, including conventional chemotherapeutics as well as targeted anticancer agents, originates (at least in part) from their ability to elicit a novel or reinstate a pre-existing tumor-specific immune response. One of the mechanisms whereby chemotherapy can stimulate the immune system to recognize and destroy malignant cells is commonly known as immunogenic cell death (ICD). Cancer cells succumbing to ICD are de facto converted into an anticancer vaccine and as such elicit an adaptive immune response. Several common chemotherapeutics share the ability of triggering ICD, as demonstrated in vaccination experiments relying on immunocompetent mice and syngeneic cancer cells. A large number of ongoing clinical trials involve such ICD inducers, often (but not always) as they are part of the gold standard therapeutic approach against specific neoplasms. In this Trial Watch, we summarize the latest advances on the use of cyclophosphamide, doxorubicin, epirubicin, oxaliplatin, and mitoxantrone in cancer patients, discussing high-impact studies that have been published during the last 13 months as well as clinical trials that have been initiated in the same period to assess the antineoplastic profile of these immunogenic drugs as off-label therapeutic interventions.

Toll-like receptors (TLRs) have first been characterized for their capacity to detect conserved microbial components like lipopolysaccharide (LPS) and double-stranded RNA, resulting in the elicitation of potent (innate) immune responses against invading pathogens. More recently, TLRs have also been shown to promote the activation of the cognate immune system against cancer cells. Today, only three TLR agonists are approved by FDA for use in humans: the bacillus Calmette-Guerin (BCG), monophosphoryl lipid A (MPL) and imiquimod. BCG (an attenuated strain of Mycobacterium bovis) is mainly used as a vaccine against tuberculosis, but also for the immunotherapy of in situ bladder carcinoma. MPL (derived from the LPS of Salmonella minnesota) is included in the formulation of Cervarix®, a vaccine against human papillomavirus-16 and -18. Imiquimod (a synthetic imidazoquinoline) is routinely employed for actinic keratosis, superficial basal cell carcinoma, and external genital warts (condylomata acuminata). In this Trial Watch, we will summarize the results of recently completed clinical trials and discuss the progress of ongoing studies that have evaluated/are evaluating FDA-approved TLR agonists as off-label medications for cancer therapy.

Progressing malignancies establish robust immunosuppressive networks that operate both systemically and locally. In particular, as tumors escape immunosurveillance, they recruit increasing amounts of myeloid and lymphoid cells that exert pronounced immunosuppressive effects. These cells not only prevent the natural recognition of growing neoplasms by the immune system, but also inhibit anticancer immune responses elicited by chemo-, radio- and immuno therapeutic interventions. Throughout the past decade, multiple strategies have been devised to counteract the accumulation or activation of tumor-infiltrating immunosuppressive cells for therapeutic purposes. Here, we review recent preclinical and clinical advances on the use of small molecules that target the immunological tumor microenvironment for cancer therapy. These agents include inhibitors of indoleamine 2,3-dioxigenase 1 (IDO1), prostaglandin E2, and specific cytokine receptors, as well as modulators of intratumoral purinergic signaling and arginine metabolism.

Studies suggest the implication of CD16(+) subpopulations (CD14(+)CD16(+), CD14(dim)CD16(+)) in inflammatory diseases. We aimed to determine the frequency of these subpopulations during weight loss in obesity and diabetes, conditions associated with changes in systemic inflammation, and we tested the link with subclinical atherosclerosis.CD14(dim)CD16(+) and CD14(+)CD16(+) frequencies were measured by flow cytometry in lean subjects, obese subjects before and after a hypocaloric diet or gastric surgery, and obese diabetic subjects before and after gastric surgery. Both monocyte subsets were increased in obese subjects, with a significant enrichment of the CD14(dim)CD16(+) subpopulation in obese diabetic patients. Multivariate analysis demonstrated a link between the percentages of CD14(dim)CD16(+) monocytes and glycemia, independent of fat mass. Drastic weight loss led to a sharp decrease of this subset, the variations of which were strongly related to fat mass changes. A reduction of at least 5% of fat mass was sufficient to observe a significant decrease of CD14(dim)CD16(+) monocytes. A diminution of the CD14(+)CD16(+) subset was also observed during weight loss and was associated with a decrease in intima-media thickness.This work demonstrates a major impact of fat mass variations on CD14(dim)CD16(+) monocyte subsets and that the decrease in the CD14(+)CD16(+) subpopulation is linked to a reduction of subclinical atherosclerosis.URL: http://clinicaltrials.gov. Unique identifier: NCT00476658.

Cancer initiation, progression, and invasion occur in a complex and dynamic microenvironment which depends on the hosts and sites where tumors develop. Tumors arising in mucosal tissues may progress in an inflammatory context linked to local viral and/or bacterial infections. At the opposite, tumors developing in immunoprivileged sites are protected from microorganisms and grow in an immunosuppressive environment. In the present review, we summarize and present our recent data on the influence of infectious context and immune cell infiltration organization in human Non-Small Cell Lung Cancers (NSCLC) progression. We show that stimulation of tumor cells by TLR for viral ssRNA, such as TLR7/8, or bacteria, such as TLR4, promotes cell survival and induces chemoresistance. On the opposite, stimulation by TLR3, receptor for double-stranded viral RNA, decreases tumor cell viability and induces chemosensitivity in some lung tumor cell lines. Since fresh lung tumor cells exhibit a gene expression profile characteristic of TLR-stimulated lung tumor cell lines, we suspect that viral and bacterial influence may not only act on the host immune system but also directly on tumor growth and sensitivity to chemotherapy. The stroma of NSCLC contains tertiary lymphoid structures (or Tumor-induced Bronchus-Associated Lymphoid Tissues (Ti-BALT)) with mature DC, follicular DC, and T and B cells. Two subsets of immature DC, Langerhans cells (LC) and interstitial DC (intDC), were detected in the tumor nests and the stroma, respectively. Here, we show that the densities of the three DC subsets, mature DC, LC, and intDC, are highly predictive of disease-specific survival in a series of 74 early-stage NSCLC patients. We hypothesize that the mature DC may derive from local activation and migration of the immature DC--and especially LC which contact the tumor cells--to the tertiary lymphoid structures, after sampling and processing of the tumor antigens. In view of the prominent role of DC in the immune response, we suggest that the microenvironment of early-stage NSCLC may allow the in situ activation of the adaptive response. Finally, we find that the eyes or brain of mice with growing B cell lymphoma are infiltrated with T cells and that the cytokines produced ex vivo by the tumoral tissues have an impaired Th1 cytokine profile. Our work illustrates that the host and external tumor microenvironments are multifaceted and strongly influence tumor progression and anti-tumor immune responses.

The success of active immunotherapy is based on the vaccine's ability to overcome immune tolerance through recalibrating the immune system so that it is able to recognize tumor antigens as foreign rather than self. In this study, we used a lentiviral vector system to target human telomerase reverse transcriptase (lv-hTERT), a widely expressed tumor antigen. Immunization of HLA-A*0201 transgenic HHD mice with recombinant lv-hTERT vector induces potent and diversified cytotoxic T lymphocyte responses that recognize in vitro murine tumor cells, which overexpress telomerase. Compared with peptide-based vaccinations, the lv-hTERT vector triggers better and more sustained CD8+ T-cell response against self/TERT epitope in vivo. The study found that the additional use of a heterologous boosted vaccination drastically improves self/TERT-specific CD8 responses in lv-hTERT primed mice. Both primary and long-lasting self/TERT-specific CD8+ T-cell responses induced with Iv-hTERT vector required the presence of CD4 T cells in vivo. This lv-hTERT–based active immunotherapy efficiently inhibits the growth of telomerase expressing tumors (B16/HLA-A2.1 murine melanoma) in HHD mice. These data show that targeting hTERT with lentivector is highly effective in stimulating a broad range of CD8 T-cell immunity that can be exploited for cancer immunotherapy.

Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations. Converging concepts were identified: enhanced knowledge of interferon-related pathways was found to be central to the understanding of immune-mediated tissue-specific destruction (TSD) of which tumor rejection is a representative facet. Although the expression of interferon-stimulated genes (ISGs) likely mediates the inflammatory process leading to tumor rejection, it is insufficient by itself and the associated mechanisms need to be identified. It is likely that adaptive immune responses play a broader role in tumor rejection than those strictly related to their antigen-specificity; likely, their primary role is to trigger an acute and tissue-specific inflammatory response at the tumor site that leads to rejection upon recruitment of additional innate and adaptive immune mechanisms. Other candidate systemic and/or tissue-specific biomarkers were recognized that might be added to the list of known entities applicable in immunotherapy trials. The need for a systematic approach to biomarker discovery that takes advantage of powerful high-throughput technologies was recognized; it was clear from the current state of the science that immunotherapy is still in a discovery phase and only a few of the current biomarkers warrant extensive validation. It was, finally, clear that, while current technologies have almost limitless potential, inadequate study design, limited standardization and cross-validation among laboratories and suboptimal comparability of data remain major road blocks. The institution of an interactive consortium for high throughput molecular monitoring of clinical trials with voluntary participation might provide cost-effective solutions.

Purpose The role of regulatory T cells (Tregs) in the immune evasion of tumors is usually prominent. The aim of this study was to assess the presence and role of Tregs in a murine model of primary intraocular B-cell lymphoma (PIOL). Methods We used a syngeneic model of PIOL in immunocompetent BALB/c mice. Immunohistochemistry and flow cytometric analysis have been performed to study the tumor growth and the immune infiltrate. Depletion of Tregs was achieved using intraperitoneal injection of anti-CD25 mAb (PC61). Splenectomy was performed to study the role of induced Tregs. Results Tregs were recruited in PIOL eyes (16.2%) compared to control eyes (1.2%, p

One particular paradigm of anticancer immunotherapy relies on the administration of (potentially) tumor-reactive immune effector cells. Generally, these cells are obtained from autologous peripheral blood lymphocytes (PBLs) ex vivo (in the context of appropriate expansion, activation and targeting protocols), and re-infused into lymphodepleted patients along with immunostimulatory agents. In spite of the consistent progress achieved throughout the past two decades in this field, no adoptive cell transfer (ACT)-based immunotherapeutic regimen is currently approved by regulatory agencies for use in cancer patients. Nonetheless, the interest of oncologists in ACT-based immunotherapy continues to increase. Accumulating clinical evidence indicates indeed that specific paradigms of ACT, such as the infusion of chimeric antigen receptor (CAR)-expressing autologous T cells, are associated with elevated rates of durable responses in patients affected by various neoplasms. In line with this notion, clinical trials investigating the safety and therapeutic activity of ACT in cancer patients are being initiated at an ever increasing pace. Here, we review recent preclinical and clinical advances in the development of ACT-based immunotherapy for oncological indications.

Immunomodulatory monoclonal antibodies (mAbs) differ from their tumor-targeting counterparts because they exert therapeutic effects by directly interacting with soluble or (most often) cellular components of the immune system. Besides holding promise for the treatment of autoimmune and inflammatory disorders, immunomodulatory mAbs have recently been shown to constitute a potent therapeutic weapon against neoplastic conditions. One class of immunomodulatory mAbs operates by inhibiting safeguard systems that are frequently harnessed by cancer cells to establish immunological tolerance, the so-called “immune checkpoints.” No less than 3 checkpoint-blocking mAbs have been approved worldwide for use in oncological indications, 2 of which during the past 12 months. These molecules not only mediate single-agent clinical activity in patients affected by specific neoplasms, but also significantly boost the efficacy of several anticancer chemo-, radio- or immunotherapies. Here, we summarize recent advances in the development of checkpoint-blocking mAbs, as well as of immunomodulatory mAbs with distinct mechanisms of action.

The European Academy of Tumor Immunology (EATI, official website: http://eati.landesbioscience.com/index.html) has been founded in 2011 with the idea of creating a novel organization that responds to the need of structuring the European research space in this expanding, clinically ever more important area of research. Rapidly, this initiative, which regroups (part of) the elite of tumor immunologists, has been joined by 110 scientists, who accepted to join EATI as founding members. Obviously, EATI will not enter in competition with existing prestigious organizations, be they supranational (such as the Cancer Research Institute, CRI; the European Society for Cancer Immunology and Immunotherapy, ESCII; and the Society for the Immunotherapy of Cancer, SITC), or national [such as the Cancer Immunology Working Group, CIMM, of the American Association for Cancer Reserch; the (German) Association for Cancer Immunotherapy, CIMT; the (US) Cancer Immunotherapy Consortium, CIC; the (US) Cancer Vaccine Consortium, CV...

Immunostimulatory monoclonal antibodies (mAbs) exert antineoplastic effects by eliciting a novel or reinstating a pre-existing antitumor immune response. Most often, immunostimulatory mAbs activate T lymphocytes or natural killer (NK) cells by inhibiting immunosuppressive receptors, such as cytotoxic T lymphocyte-associated protein 4 (CTLA4) or programmed cell death 1 (PDCD1, best known as PD-1), or by engaging co-stimulatory receptors, like CD40, tumor necrosis factor receptor superfamily, member 4 (TNFRSF4, best known as OX40) or TNFRSF18 (best known as GITR). The CTLA4-targeting mAb ipilimumab has been approved by the US Food and Drug Administration for use in patients with unresectable or metastatic melanoma in 2011. The therapeutic profile of ipilimumab other CTLA4-blocking mAbs, such as tremelimumab, is currently being assessed in subjects affected by a large panel of solid neoplasms. In the last few years, promising clinical results have also been obtained with nivolumab, a PD-1-targeting mAb formerly known as BMS-936558. Accordingly, the safety and efficacy of nivolumab and other PD-1-blocking molecules are being actively investigated. Finally, various clinical trials are underway to test the therapeutic potential of OX40- and GITR-activating mAbs. Here, we summarize recent findings on the therapeutic profile of immunostimulatory mAbs and discuss clinical trials that have been launched in the last 14 months to assess the therapeutic profile of these immunotherapeutic agents.

Dendritic cells (DCs) occupy a privileged position at the interface between innate and adaptive immunity, orchestrating a large panel of responses to both physiological and pathological cues. In particular, whereas the presentation of antigens by immature DCs generally results in the development of immunological tolerance, mature DCs are capable of priming robust, and hence therapeutically relevant, adaptive immune responses. In line with this notion, functional defects in the DC compartment have been shown to etiologically contribute to pathological conditions including (but perhaps not limited to) infectious diseases, allergic and autoimmune disorders, graft rejection and cancer. Thus, the possibility of harnessing the elevated immunological potential of DCs for anticancer therapy has attracted considerable interest from both researchers and clinicians over the last decade. Alongside, several methods have been developed not only to isolate DCs from cancer patients, expand them, load them with tumor-associated antigens and hence generate highly immunogenic clinical grade infusion products, but also to directly target DCs in vivo. This intense experimental effort has culminated in 2010 with the approval by the US FDA of a DC-based preparation (sipuleucel-T, Provenge®) for the treatment of asymptomatic or minimally symptomatic metastatic castration-refractory prostate cancer. As an update to the latest Trial Watch dealing with this exciting field of research (October 2012), here we summarize recent advances in DC-based anticancer regimens, covering both high-impact studies that have been published during the last 13 mo and clinical trials that have been launched in the same period to assess the antineoplastic potential of this variant of cellular immunotherapy.

Adoptive cell transfer (ACT) represents a prominent form of immunotherapy against malignant diseases. ACT is conceptually distinct from dendritic cell-based approaches (which de facto constitute cellular vaccines) and allogeneic transplantation (which can be employed for the therapy of hematopoietic tumors) as it involves the isolation of autologous lymphocytes exhibiting antitumor activity, their expansion/activation ex vivo and their reintroduction into the patient. Re-infusion is most often performed in the context of lymphodepleting regimens (to minimize immunosuppression by host cells) and combined with immunostimulatory interventions, such as the administration of Toll-like receptor agonists. Autologous cells that are suitable for ACT protocols can be isolated from tumor-infiltrating lymphocytes or generated by engineering their circulating counterparts for the expression of transgenic tumor-specific T-cell receptors. Importantly, lymphocytes can be genetically modified prior to re-infusion for increasing their persistence in vivo, boosting antitumor responses and minimizing side effects. Moreover, recent data indicate that exhausted antitumor T lymphocytes may be rejuvenated in vitro by exposing them to specific cytokine cocktails, a strategy that might considerably improve the clinical success of ACT. Following up the Trial Watch that we published on this topic in the third issue of OncoImmunology (May 2012), here we summarize the latest developments in ACT-related research, covering both high-impact studies that have been published during the last 13 months and clinical trials that have been initiated in the same period to assess the antineoplastic profile of this form of cellular immunotherapy.