Outcome Of Cancer Immunotherapy Research Articles

Improving Cancer Immunotherapy Outcomes Using Biomaterials

AbstractImmunotherapy has made great strides in improving clinical outcomes in cancer treatment. However, few patients exhibit adequate response rates for key outcome measures and desired long‐term responses, and they often suffer systemic side effects due to the dynamic nature of the immune system. This has motivated a search for alternative strategies to improve unsatisfactory immunotherapeutic outcomes. In recent years, biomaterial‐assisted immunotherapy has shown promise in cancer treatment with improved therapeutic efficacy and reduced side effects. These biomaterials have illuminated fundamental mechanisms underlying the immunoediting process, while greatly improving the efficacy of chimeric antigen receptor (CAR) T‐cell therapy, cancer vaccine therapy, and immune checkpoint blockade therapy. This Minireview discusses recent advances in engineered biomaterials that address limitations associated with conventional cancer immunotherapies.

Improving Cancer Immunotherapy Outcomes Using Biomaterials.

Immunotherapy has made great strides in improving clinical outcomes in cancer treatment. However, few patients exhibit adequate response rates for key outcome measures and desired long-term responses, and they often suffer systemic side effects due to the dynamic nature of the immune system. This has motivated a search for alternative strategies to improve unsatisfactory immunotherapeutic outcomes. In recent years, biomaterial-assisted immunotherapy has shown promise in cancer treatment with improved therapeutic efficacy and reduced side effects. These biomaterials have illuminated fundamental mechanisms underlying the immunoediting process, while greatly improving the efficacy of chimeric antigen receptor (CAR) T-cell therapy, cancer vaccine therapy, and immune checkpoint blockade therapy. This Minireview discusses recent advances in engineered biomaterials that address limitations associated with conventional cancer immunotherapies.

YYFZBJS ameliorates colorectal cancer progression in ApcMin/+ mice by remodeling gut microbiota and inhibiting regulatory T-cell generation

BackgroundProgression of Colorectal cancer (CRC) is influenced by single or compounded environmental factors. Accumulating evidence shows that microbiota can influence the outcome of cancer immunotherapy. T cell, one of the main populations of effector immune cells in antitumor immunity, has been considered as a double-edged sword during the progression of CRC. Our previous studies indicate that traditional Chinese herbs (TCM) have potential anticancer effects in improving quality of life and therapeutic effect. However, little is known about the mechanism of TCM formula in cancer prevention.MethodsHere, we used C57BL/6 J ApcMin/+ mice, an animal model of human intestinal tumorigenesis, to investigate the gut bacterial diversity and their mechanisms of action in gastrointestinal adenomas, and to evaluate the effects of Yi-Yi-Fu-Zi-Bai-Jiang-San (YYFZBJS) on of colon carcinogenesis in vivo and in vitro. Through human-into-mice fecal microbiota transplantation (FMT) experiments from YYFZBJS volunteers or control donors, we were able to differentially modulate the tumor microbiome and affect tumor growth as well as tumor immune infiltration.ResultsWe report herein, YYFZBJS treatment blocked tumor initiation and progression in ApcMin/+ mice with less change of body weight and increased immune function. Moreover, diversity analysis of fecal samples demonstrated that YYFZBJS regulated animal’s natural gut flora, including Bacteroides fragilis, Lachnospiraceae and so on. Intestinal tumors from conventional and germ-free mice fed with stool from YYFZBJS volunteers had been decreased. Some inflammation’ expression also have been regulated by the gut microbiota mediated immune cells. Intestinal lymphatic, and mesenteric lymph nodes (MLN), accumulated CD4+ CD25+ Foxp3 positive Treg cells were reduced by YYFZBJS treatment in ApcMin/+ mice. Although YYFZBJS had no inhibition on CRC cell proliferation by itself, the altered Tregs mediated by YYFZBJS repressed CRC cancer cell growth, along with reduction of the phosphorylation of β-catenin.ConclusionsIn conclusion, we demonstrated that gut microbiota and Treg were involved in CRC development and progression, and we propose YYFZBJS as a new potential drug option for the treatment of CRC.6W2ydHZG-3mvoN8oBgCZVNVideo abstractGraphical abstract

Obesity induces limited changes to systemic and local immune profiles in treatment-naive human clear cell renal cell carcinoma.

Understanding the effects of obesity on the immune profile of renal cell carcinoma (RCC) patients is critical, given the rising use of immunotherapies to treat advanced disease and recent reports of differential cancer immunotherapy outcomes with obesity. Here, we evaluated multiple immune parameters at the genetic, soluble protein, and cellular levels in peripheral blood and renal tumors from treatment-naive clear cell RCC (ccRCC) subjects (n = 69), to better understand the effects of host obesity (Body Mass Index "BMI" ≥ 30 kg/m2) in the absence of immunotherapy. Tumor-free donors (n = 38) with or without obesity were used as controls. In our ccRCC cohort, increasing BMI was associated with decreased percentages of circulating activated PD-1+CD8+ T cells, CD14+CD16neg classical monocytes, and Foxp3+ regulatory T cells (Tregs). Only CD14+CD16neg classical monocytes and Tregs were reduced when obesity was examined as a categorical variable. Obesity did not alter the percentages of circulating IFNγ+ CD8 T cells or IFNγ+, IL-4+, or IL-17A+ CD4 T cells in ccRCC subjects. Of 38 plasma proteins analyzed, six (CCL3, IL-1β, IL-1RA, IL-10, IL-17, and TNFα) were upregulated specifically in ccRCC subjects with obesity versus tumor-free controls with obesity. IGFBP-1 was uniquely decreased in ccRCC subjects with obesity versus non-obese ccRCC subjects. Immunogenetic profiling of ccRCC tumors revealed that 93% of examined genes were equivalently expressed and no changes in cell type scores were found in stage-matched tumors from obesity category II/III versus normal weight (BMI ≥ 35 kg/m2 versus 18.5-24.9 kg/m2, respectively) subjects. Intratumoral PLGF and VEGF-A proteins were elevated in ccRCC subjects with obesity. Thus, in ccRCC patients with localized disease, obesity is not associated with widespread detrimental alterations in systemic or intratumoral immune profiles. The effects of combined obesity and immunotherapy administration on immune parameters remains to be determined.

Prolonged Persistence of Chimeric Antigen Receptor (CAR) T Cell in Adoptive Cancer Immunotherapy: Challenges and Ways Forward.

CAR T cell qualities, such as persistence and functionality play important roles in determining the outcome of cancer immunotherapy. In spite of full functionality, it has been shown that poor persistence of CAR T cells can limit an effective antitumor immune response. Here, we outline specific strategies that can be employed to overcome intrinsic and extrinsic barriers to CAR T cell persistence. We also offer our viewpoint on how growing use of CAR T cells in various cancers may require modifications in the intrinsic and extrinsic survival signals of CAR T cells. We anticipate these amendments will additionally provide the rationales for generation of more persistent, and thereby, more effective CAR T cell treatments. CAR T cell qualities, such as persistence and functionality play important roles in determining the outcome of cancer immunotherapy. In spite of full functionality, it has been shown that poor persistence of CAR T cells can limit an effective antitumor immune response. Here, we outline specific strategies that can be employed to overcome intrinsic and extrinsic barriers to CAR T cell persistence. We also offer our viewpoint on how growing use of CAR T cells in various cancers may require modifications in the intrinsic and extrinsic survival signals of CAR T cells. We anticipate these amendments will additionally provide the rationales for generation of more persistent, and thereby, more effective CAR T cell treatments.

Spatially resolved analyses link genomic and immune diversity and reveal unfavorable neutrophil activation in melanoma

Complex tumor microenvironmental (TME) features influence the outcome of cancer immunotherapy (IO). Here we perform immunogenomic analyses on 67 intratumor sub-regions of a PD-1 inhibitor-resistant melanoma tumor and 2 additional metastases arising over 8 years, to characterize TME interactions. We identify spatially distinct evolution of copy number alterations influencing local immune composition. Sub-regions with chromosome 7 gain display a relative lack of leukocyte infiltrate but evidence of neutrophil activation, recapitulated in The Cancer Genome Atlas (TCGA) samples, and associated with lack of response to IO across three clinical cohorts. Whether neutrophil activation represents cause or consequence of local tumor necrosis requires further study. Analyses of T-cell clonotypes reveal the presence of recurrent priming events manifesting in a dominant T-cell clonotype over many years. Our findings highlight the links between marked levels of genomic and immune heterogeneity within the physical space of a tumor, with implications for biomarker evaluation and immunotherapy response.

Association of Long Noncoding RNA Biomarkers With Clinical Immune Subtype and Prediction of Immunotherapy Response in Patients With Cancer

Long noncoding RNAs (lncRNAs) are involved in innate and adaptive immunity in cancer by mediating the functional state of immunologic cells, pathways, and genes. However, whether lncRNAs are associated with immune molecular classification and clinical outcomes of cancer immunotherapy is largely unknown. To explore lncRNA-based immune subtypes associated with survival and response to cancer immunotherapy and to present a novel lncRNA score for immunotherapy prediction using computational algorithms. In this cohort study, an individual patient analysis based on a phase 2, single-arm clinical trial and multicohort was performed from June 25 through September 30, 2019. Data are from the phase 2 IMvigor210 trial and from The Cancer Genome Atlas (TCGA). The study analyzed lncRNA and genomic data of 348 patients with bladder cancer from the IMvigor210 trial and 71 patients with melanoma from TCGA who were treated with immunotherapy. In addition, a pancancer multicohort that included 2951 patients was obtained from TCGA. The primary end point was overall survival (OS). Among 348 patients from the IMvigor210 trial (272 [78.2%] male) and 71 patients with melanoma from TCGA (mean [SD] age, 58.3 [13.4] years; 37 [52.1%] female), 4 distinct classes with statistically significant differences in OS (median months, not reached vs 9.6 vs 8.1 vs 6.7 months; P = .002) were identified. The greatest OS benefit was obtained in the immune-active class, as characterized by the immune-functional lncRNA signature and high CTL infiltration. Patients with low vs high lncRNA scores had statistically significantly longer OS (hazard ratio, 0.32; 95% CI, 0.24-0.42; P < .001) in the IMvigor210 trial and across various cancer types. The lncRNA score was associated with immunotherapeutic OS benefit in the IMvigor210 trial cohort (area under the curve [AUC], 0.79 at 12 months and 0.77 at 20 months) and in TCGA melanoma cohort (AUC, 0.87 at 24 months), superior tumor alteration burden, programmed cell death ligand 1 (PD-L1) expression, and cytotoxic T-lymphocyte (CTL) infiltration. Addition of the lncRNA score to the combination of tumor alteration burden, PD-L1 expression, and CTL infiltration to build a novel multiomics algorithm correlated more strongly with OS in the IMvigor210 trial cohort (AUC, 0.81 at 12 months and 0.80 at 20 months). This study identifies novel lncRNA-based immune classes in cancer immunotherapy and recommends immunotherapy for patients in the immune-active class. In addition, the study recommends that the lncRNA score should be integrated into multiomic panels for precision immunotherapy.

Obesity and CD8 T cell metabolism: Implications for anti-tumor immunity and cancer immunotherapy outcomes.

Obesity is an established risk factor for many cancers and has recently been found to alter the efficacy of T cell-based immunotherapies. Currently, however, the effects of obesity on immunometabolism remain unclear. Understanding these associations is critical, given the fact that T cell metabolism is tightly linked to effector function. Thus, any obesity-associated changes in T cell bioenergetics are likely to drive functional changes at the cellular level, alter the metabolome and cytokine/chemokine milieu, and impact cancer immunotherapy outcomes. Here, we provide a brief overview of T cell metabolism in the presence and absence of solid tumor growth and summarize current literature regarding obesity-associated changes in T cell function and bioenergetics. We also discuss recent findings related to the impact of host obesity on cancer immunotherapy outcomes and present potential mechanisms by which T cell metabolism may influence therapeutic efficacy. Finally, we describe promising pharmaceutical therapies that are being investigated for their ability to improve CD8 T cell metabolism and enhance cancer immunotherapy outcomes in patients, regardless of their obesity status.

Melittin-lipid nanoparticles target to lymph nodes and elicit a systemic anti-tumor immune response

Targeted delivery of a nanovaccine loaded with a tumor antigen and adjuvant to the lymph nodes (LNs) is an attractive approach for improving cancer immunotherapy outcomes. However, the application of this technique is restricted by the paucity of suitable tumor-associated antigens (TAAs) and the sophisticated technology required to identify tumor neoantigens. Here, we demonstrate that a self-assembling melittin-lipid nanoparticle (α-melittin-NP) that is not loaded with extra tumor antigens promotes whole tumor antigen release in situ and results in the activation of antigen-presenting cells (APCs) in LNs. Compared with free melittin, α-melittin-NPs markedly enhance LN accumulation and activation of APCs, leading to a 3.6-fold increase in antigen-specific CD8+ T cell responses. Furthermore, in a bilateral flank B16F10 tumor model, primary and distant tumor growth are significantly inhibited by α-melittin-NPs, with an inhibition rate of 95% and 92%, respectively. Thus, α-melittin-NPs induce a systemic anti-tumor response serving as an effective LN-targeted whole-cell nanovaccine.

Cell and tissue engineering in lymph nodes for cancer immunotherapy.

In cancer, lymph nodes (LNs) coordinate tumor antigen presentation necessary for effective antitumor immunity, both at the levels of local cellular interactions and tissue-level organization. In this review, we examine how LNs may be engineered to improve the therapeutic outcomes of cancer immunotherapy. At the cellular scale, targeting the LNs impacts the potency of cancer vaccines, immune checkpoint blockade, and adoptive cell transfer. On a tissue level, macro-scale biomaterials mimicking LN features can function as immune niches for cell reprogramming or delivery in vivo, or be utilized in vitro to enable preclinical testing of drugs and vaccines. We additionally review strategies to induce ectopic lymphoid sites reminiscent of LNs that may improve antitumor T cell priming.

MTOR Inhibitors Can Enhance the Anti-Tumor Effects of DNA Vaccines through Modulating Dendritic Cell Function in the Tumor Microenvironment.

The life span of dendritic cells (DCs) can become short following induced activation, which is associated with metabolic transition due to the regulation of mechanistic target of rapamycin (mTOR). The purpose of this study was to investigate the potential of inhibiting mTOR to modulate DC functions for elevating the anti-tumor effects of DNA vaccines. Therefore, the influences of various inhibitors of mTOR (mTORi) on the expressions of DC maturation markers, the abilities of antigen presenting and processing of BMM-derived DCs and the tumor killing effects of E7-specific CD8+ T lymphocytes activated by BMM-derived DCs were in vitro examined. The anti-tumor effects of connective tissue growth factor (CTGF)/E7 DNA vaccine and/or mTORi were also in vivo analyzed. In our study, suppressive effects of mTORi on the DC maturation markers expressed on BMMCs could be reversed. The mTORi-treated mature BMM-derived DCs tended to be non-apoptotic. These mTORi-treated BMM-derived DCs could have better antigen presenting and processing abilities. The E7-specific cytotoxic CD8+ T lymphocytes could have more potent tumoricidal activity following activation of mTORi-treated BMM-derived DCs. For tumor-bearing mice, those treated with CTGF/E7 DNA vaccine and mTORi indeed can have higher percentages of mature DCs in the TME, better disease control and longer survivals. Consequently, application of mTORi can be a pharmacological approach for temporally increasing life span, antigen presenting and antigen processing of DCs to strengthen the therapeutic outcome of cancer immunotherapy.

Transcriptome Profile and Clinical Characteristics of CTLA-4 in Diffuse Gliomas

CTLA-4, identified as an immune checkpoint, has been widely reported to contribute to downregulation of immune responses to anti-tumor activity. Anti-CTLA-4 provides a novel strategy to improve the outcome of cancer immunotherapy, but the role of CTLA-4 needs to be addressed in glioma. To investigate the role of CTLA-4 in diffuse gliomas, we analyzed the transcriptome level data of CTLA-4 and evaluated its clinical prognostic value. 1022 glioma samples with transcriptome data were enrolled into this study, including 325 RNA-seq data from CGGA and 697 RNA-seq data from TCGA. Clinical and molecular data were also obtained. R project was the main tool for statistical analysis and graphical work. High-grade gliomas exhibited high expression of CTLA-4 while IDH wildtype gliomas showed CTLA-4 enrichment. According to TCGA transcriptional classification in gliomas, mesenchymal subtype displayed significantly higher CTLA-4 expression than other molecular subtypes. Gene ontology analysis demonstrated that CTLA-4 and correlated genes were involved in immune responses and inflammatory activities in diffuse gliomas. Through the analysis of transcriptomic data, CTLA-4 expression strongly correlated with immune cell populations and inflammatory activity. Survival analysis suggested that high expression of CTLA-4 was associated with poor prognosis in gliomas and may serve as an indicator of outcome in gliomas. High CTLA-4 expression is closely related to malignancy in diffuse gliomas and predicts poor outcome. Meanwhile, CTLA-4 plays an important role in regulating T cell activation and antitumor responses in gliomas. Therefore, blocking CTLA-4 is a potential target for developing the immunotherapy of gliomas. Funding: This work was supported by the capital health research and development of special (2014-2-1072); Beijing Municipal Natural Science Foundation (7142054) and National Natural Science Foundation of China (81471229). Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: This study was approved by Capital Medical University Institutional Review Board (IRB).

Amphiphilic nanoparticle delivery enhances the anticancer efficacy of a TLR7 ligand via local immune activation

Although immunotherapy shows great promise for the long-term control of cancer, many tumors still fail to respond to treatment. To improve the outcome, the delivery of immunostimulants to the lymph nodes draining the tumor, where the antitumor immune response is initiated, is key. Efforts to use nanoparticles as carriers for cancer immunotherapy have generally required targeting agents and chemical modification of the drug, and have unfortunately resulted in low delivery and therapeutic efficiency. Here, we report on the efficacy of gold nanoparticles with approximately 5 nm hydrodynamic diameter coated with a mixture of 1-octanethiol and 11-mercaptoundecanesulfonic acid for the delivery of an immunostimulatory TLR7 ligand to tumor-draining lymph nodes. The drug was loaded without modification through nonspecific adsorption into the ligand shell of the nanoparticles, taking advantage of their amphiphilic nature. After loading, nanoparticles retained their stability in solution without significant premature release of the drug, and the drug cargo was immunologically active. Upon subcutaneous injection into tumor-bearing mice, the drug-loaded particles were rapidly transported to the tumor-draining lymph nodes. There, they induced a local immune activation and fostered a cytotoxic T-cell response that was specific for the tumor. Importantly, the particle-delivered TLR7 ligand blocked the growth of large established tumors and significantly prolonged survival compared to the free form of the drug. Thus, we demonstrate for the first time that nanoparticle delivery of a TLR7 immunostimulant to the tumor-draining lymph nodes enhances antitumor immunity and improves the outcome of cancer immunotherapy.

BDCA1+CD14+ Immunosuppressive Cells in Cancer, a Potential Target?

Dendritic cell (DC) vaccines show promising effects in cancer immunotherapy. However, their efficacy is affected by a number of factors, including (1) the quality of the DC vaccine and (2) tumor immune evasion. The recently characterized BDCA1+CD14+ immunosuppressive cells combine both aspects; their presence in DC vaccines may directly hamper vaccine efficacy, whereas, in patients, BDCA1+CD14+ cells may suppress the induced immune response in an antigen-specific manner systemically and at the tumor site. We hypothesize that BDCA1+CD14+ cells are present in a broad spectrum of cancers and demand further investigation to reveal treatment opportunities and/or improvement for DC vaccines. In this review, we summarize the findings on BDCA1+CD14+ cells in solid cancers. In addition, we evaluate the presence of BDCA1+CD14+ cells in leukemic cancers. Preliminary results suggest that the presence of BDCA1+CD14+ cells correlates with clinical features of acute and chronic myeloid leukemia. Future research focusing on the differentiation from monocytes towards BDCA1+CD14+ cells could reveal more about their cell biology and clinical significance. Targeting these cells in cancer patients may improve the outcome of cancer immunotherapy.

Abstract 718: Nanoparticle-based tumor cell lysate vaccine for cancer immunotherapy

Abstract Introduction Combination of tumor-associated antigen (TAA) and toll-like receptor (TLR) agonists can facilitate a potent anticancer immune response. Synthetic peptides, which are derived from antigens that are highly elevated or only expressed in tumor tissue, have been investigated as a source of TAA. However, these peptides are not available for all tumor types and often poorly immunogenic. Whole tumor cell lysate is a promising alternate antigen source that seeks to overcome some of the limitations associated with peptide-based vaccines. In this study, we utilized whole tumor cell lysate as antigen source and a novel TLR 7/8 agonist encapsulating nanoparticles as adjuvant to formulate the cancer vaccine and examined its efficacy against subcutaneous (S.C.) tumor models. Methods A new imidazaquinoline-based TLR 7/8 agonist (termed ‘522') was encapsulated in poly(lactide-co-glycolide) (PLGA) nanoparticles using emulsion solvent evaporation method to formulate the vaccine adjuvant. The adjuvant (522NP) was used in combination with whole tumor cell lysate (CL) prepared from murine bladder carcinoma (MB49) cells. Immunocompetent C57BL/6 mice were immunized subcutaneously with 5 doses of cell-lysate vaccine or various control treatments. Two days after the final vaccination dose, mice were sacrificed and organs were harvested. Splenocytes were analyzed using flow cytometry to measure antigen (Ag)-specific CD8 T cell response. We investigated whether prophylactic and therapeutic CL+522NP immunization can delay tumor growth and improve survival in MB49 S.C. tumor models. Results CD11ahighCD8low CD8 T cells were examined as they represent Ag-experienced CD8 T cells that can respond to Ag. Frequency of CD11ahigh CD8low CD8 T cells increased in mice vaccinated with CL+522NP. In the prophylactic model, CL+522NP significantly delayed tumor growth compared to that in other control groups. On d 30, average tumor volumes reached ~1000 mm3 in untreated mice compared to ~500 mm3 in CL alone and CL+Soluble522 treated groups. However, CL+522NP vaccinated mice showed remarkably very little tumor growth (~122 mm3) over the same time period. In the therapeutic model, only CL+522NP treatment was effective in delaying tumor growth. Unlike in the prophylactic study, where CL alone had a moderate effect, therapeutic effects were not observed from CL alone or CL+Soluble522 groups. Conclusion CL+522NPs vaccination triggered a robust anti-cancer immune response that resulted in the expansion of CD11ahigh CD8low CD8 T cells, which suggests that 522NPs enhance the immunogenicity of cell lysate and elicit Ag-specific CD8 T cell response. Furthermore, CD8 T cells generated by CL+522NPs vaccination appeared to be effective in killing tumors in both prophylactic and therapeutic tumor models. These results suggest that 522NPs are effective vaccine adjuvants capable of improving the outcome of cancer immunotherapy. Citation Format: Hyunjoon Kim, Peter Larson, Tamara A. Kucaba, Katherine A. Murphy, David M. Ferguson, Thomas S. Griffith, Jayanth Panyam. Nanoparticle-based tumor cell lysate vaccine for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 718.

Lung cancer immunotherapy outcomes in Hispanic patients.

e18665Background: Hispanics (H) in the US seem to have a lower age-adjusted mortality resulting from non-small cell lung cancer (NSCLC) compared with Non-Hispanic Whites (NHW). Immunotherapy outcom...

Regulatory T cells: a potential target in cancer immunotherapy.

Cancer immunotherapy involving blockade of immune checkpoint molecules, such as CTLA-4 and PD-1, has shown remarkable clinical success across several types of malignancies. However, a fraction of patients experience disease progression after treatment; thus, exploring resistant mechanisms for immune checkpoint inhibitors and improving their treatment outcome with additional modalities are of great importance. CD4+ regulatory T (Treg ) cells characterized by expression of the master regulatory transcription factor FOXP3 are a highly immune-suppressive subset of CD4+ T cells that maintain immune homeostasis. Several preclinical and clinical studies suggest that Treg cells hamper immune surveillance against cancer in healthy individuals, prevent the development of effective antitumor immunity in tumor-bearing patients, and promote tumor progression. Therefore, targeting Treg cells should be crucial to improving the treatment outcomes of cancer immunotherapy. Several clinical studies directly or indirectly targeting Treg cells in combination with immune checkpoint inhibitors are ongoing or being planned. Understanding the characteristics and roles of Treg cells in cancer settings could make disease-specific Treg -targeted therapy more efficacious and reduce the incidence of immune-related adverse effects mediated by Treg cell inhibition.

Microbiome: Gut microbiota sways response to cancer immunotherapy.

Three new studies provide evidence that the composition of the intestinal microbiota affects the outcome of cancer immunotherapy.

Advancing Immune and Cell-Based Therapies Through Imaging

Immunotherapies include various approaches, ranging from stimulating effector mechanisms to counteracting inhibitory and suppressive mechanisms, and creating a forum for discussing the most effective means of advancing these therapies through imaging is the focus of the newly formed Imaging in Cellular and Immune Therapies (ICIT) interest group within the World Molecular Imaging Society. Efforts are being made in the identification and validation of predictive biomarkers for a number of immunotherapies. Without predictive biomarkers, a considerable number of patients may receive treatments that have no chance of offering a benefit. This will reflect poorly on the field of immunotherapy and will yield false hopes in patients while at the same time contributing to significant cost to the healthcare system. This review summarizes the main strategies in cancer immune and cell-based therapies and discusses recent advances in imaging strategies aimed to improve cancer immunotherapy outcomes.

Mechanisms of Resistance to Immune Checkpoint Antibodies.

Immunotherapy using checkpoint inhibitors has changed the way we treat several aggressive cancers such as melanoma, non-small cell lung and head & neck cancers, among others, with durable responses achieved in the metastatic setting. However, unfortunately, the vast majority of patients do not respond to checkpoint inhibition therapy and a minority of patients, who do respond to treatment, develop secondary resistance and experience relapse by mechanisms still inadequately understood. Emerging evidence shows that alterations in multiple signaling pathways are involved in primary and/or secondary resistance to checkpoint inhibition. In this review we discuss how selected cancer-cell autonomous cues may influence the outcome of cancer immunotherapy, particularly immune checkpoint inhibition.