Project description:The success of immunotherapy in many disease entities is limited to a specific subpopulation of patients. To overcome this problem, dual blockade treatments mainly against cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed cell death receptor (ligand) 1 (PD-(L)1) axis were developed. However, due to high toxicity rates and treatment resistance, alternative pathways and novel strategies were desperately needed. Lymphocyte-associated gene 3 (LAG3) represents an inhibitory receptor, which is mainly found on activated immune cells and involved in the exhaustion of T cells in malignant diseases. Its co-expression with other inhibitory receptors, particularly with PD-1 leads to an extensive research on the blockade of LAG3 and PD-1 in preclinical settings. Interestingly, several in-vivo approaches demonstrated a highly significant clinical benefit under dual blockade, whereas the efficacy was very low in case of single agent targeting. Moreover, human tumour tissues showed co-expression of LAG3 and PD-1 in infiltrated lymphocytes, which again generated a rationale for blocking these both molecules in clinical settings. The ongoing clinical studies mainly use dual blockage of LAG3/PD-1, which demonstrated promising survival benefits and long duration of response rates. The following review focuses on the biological background and rationale of combining LAG3 with other agents and serves as an update on the state of clinical research on LAG3 targeting.
Project description:Despite the impressive impact of CTLA4 and PD1-PDL1-targeted cancer immunotherapy, a large proportion of patients with many tumor types fail to respond. Consequently, the focus has shifted to targeting alternative inhibitory receptors (IRs) and suppressive mechanisms within the tumor microenvironment. Lymphocyte activation gene-3 (LAG3) (CD223) is the third IR to be targeted in the clinic, consequently garnering considerable interest and scrutiny. LAG3 upregulation is required to control overt activation and prevent the onset of autoimmunity. However, persistent antigen exposure in the tumor microenvironment results in sustained LAG3 expression, contributing to a state of exhaustion manifest in impaired proliferation and cytokine production. The exact signaling mechanisms downstream of LAG3 and interplay with other IRs remain largely unknown. However, the striking synergy between LAG3 and PD1 observed in multiple settings, coupled with the contrasting intracellular cytoplasmic domain of LAG3 as compared with other IRs, highlights the potential uniqueness of LAG3. There are now four LAG3-targeted therapies in the clinic with many more in preclinical development, emphasizing the broad interest in this IR. Given the translational relevance of LAG3 and the heightened interest in the impact of dual LAG3/PD1 targeting in the clinic, the outcome of these trials could serve as a nexus; significantly increasing or dampening enthusiasm for subsequent targets in the cancer immunotherapeutic pipeline.
Project description:Modulation of the interaction between the immune system and the tumor microenvironment has long been a target of cancer research, including colorectal cancer (CRC). Approaches explored to date include vaccines (autologous, peptide, dendritic cell, viral and bacterial), cytokine therapy, toll-like receptors (TLRs), autologous cell therapy and checkpoint inhibition. Until recently these approaches have been shown to have only modest efficacy in reducing tumor burden. However, significant breakthroughs have been made, with the use of checkpoint inhibitors targeting programmed cell death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T lymphocyte antigen-4 (CTLA-4). Immunotherapy now represents a possible avenue of curative treatment for those with chemo-otherwise refractory tumors. Success with this approach to immunotherapy has largely been confined to tumors with high mutational burdens such as melanoma, renal cell carcinoma (RCC) and non-small cell lung cancer. This observation led to the exploration and successful use of checkpoint inhibitors in those with mismatch repair colorectal cancer which have a relatively high mutational burden. Ongoing trials are focused on further exploring the use of checkpoint inhibitors in addition to investigating the various combinations of immunotherapeutic drugs.
Project description:Cancer immunotherapy has become a new generation of anti-tumor treatment, but its indications still focus on several types of tumors that are sensitive to the immune system. Therefore, effective strategies that can expand its indications and enhance its efficiency become the key element for the further development of cancer immunotherapy. Natural products are reported to have this effect on cancer immunotherapy, including cancer vaccines, immune-check points inhibitors, and adoptive immune-cells therapy. And the mechanism of that is mainly attributed to the remodeling of the tumor-immunosuppressive microenvironment, which is the key factor that assists tumor to avoid the recognition and attack from immune system and cancer immunotherapy. Therefore, this review summarizes and concludes the natural products that reportedly improve cancer immunotherapy and investigates the mechanism. And we found that saponins, polysaccharides, and flavonoids are mainly three categories of natural products, which reflected significant effects combined with cancer immunotherapy through reversing the tumor-immunosuppressive microenvironment. Besides, this review also collected the studies about nano-technology used to improve the disadvantages of natural products. All of these studies showed the great potential of natural products in cancer immunotherapy.
Project description:Recent phase III trial results have demonstrated the effectiveness of sipuleucel-T, a therapeutic cancer vaccine, in the treatment of metastatic prostate cancer. Yet, despite the survival benefit of sipuleucel-T, questions remain about how immunologic agents can be used in the treatment of metastatic prostate cancer. The primary issue confounding researchers and practitioners about the benefits of sipuleucel-T is the lack of effect on time to progression. It may be helpful to note that recent phase II data from a different therapeutic prostate cancer vaccine (Prostvac), as well as phase III data from an anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) blocking agent in metastatic melanoma, also show improved survival without short-term changes in disease progression. Furthermore, mathematical tumor growth models provide some insight into the fact that immunologic therapies do allow for continued tumor growth, but at a slower rate, thus prolonging survival. This understanding can help to clarify the role of the newly approved sipuleucel-T in the treatment of metastatic prostate cancer. It is also possible that appropriate sequencing of therapies could further improve the clinical course for such patients. Additional clinical trials will further our understanding of the role of therapeutic cancer vaccines and add new agents to the armamentarium of therapy for patients with prostate cancer.
Project description:In the last decade, immunotherapies have revolutionised anticancer treatment. However, there is still a number of patients that do not respond or acquire resistance to these treatments. Despite several efforts to combine immunotherapy with other strategies like chemotherapy, or other immunotherapy, there is an 'urgent' need to better understand the immune landscape of the tumour microenvironment. New promising approaches, in addition to blocking co-inhibitory pathways, such those cytotoxic T-lymphocyte-associated protein 4 and programmed cell death protein 1 mediated, consist of activating co-stimulatory pathways to enhance antitumour immune responses. Among several new targets, glucocorticoid-induced TNFR-related gene (GITR) activation can promote effector T-cell function and inhibit regulatory T-cell (Treg) function. Preclinical data on GITR-agonist monoclonal antibodies (mAbs) demonstrated antitumour activity in vitro and in vivo enhancing CD8+ and CD4+ effector T-cell activity and depleting tumour-infiltrating Tregs. Phase I clinical trials reported a manageable safety profile of GITR mAbs. However, monotherapy seems not to be effective, whereas responses have been reported in combination therapy, in particular adding PD-1 blockade. Several clinical studies are ongoing and results are awaited to further develop GITR-stimulating treatments.
Project description:The immune surveillance system is complex and regulated by different actors. Programmed death protein-ligand 1 (PD-L1), the only approved biomarker in clinical practice, has proven to be imperfect in selecting patients to immune checkpoint inhibitors treatment. Therefore, new biomarkers, and new therapeutic targets, are needed to maximise the efficacy of immunotherapy. V-domain Ig Suppressor of T-cell Activation (VISTA) is a programmed death protein-1 (PD-1) homolog expressed on T cells and on antigen-presenting cells, which regulates processes of activation and repression of the immune system with not yet completely clarified mechanisms. Its blockage has demonstrated in vitro and in vivo antitumour activity. The clinical research of VISTA antagonists is ongoing. Particularly, CA-170, an orally delivered dual inhibitor of VISTA and PD-L1, has shown to have clinical efficacy in phase I and II clinical trials in different advanced solid tumour types. Further data are needed to define whether this drug class can become a new therapeutic option for patients with VISTA expressing cancers.
Project description:The success of cancer therapies with immune checkpoint inhibitors is transforming the treatment of patients with cancer and fostering cancer research. Therapies that target immune checkpoint inhibitors have shown unprecedented rates of durable long-lasting responses in patients with various cancer types, but only in a fraction of patients. Thus, novel approaches are needed to make immunotherapy more precise and also less toxic. The advances of next-generation sequencing technologies have allowed fast detection of somatic mutations in genes present in the exome of an individual tumour. Targeting neoantigens, the mutated peptides expressed only by tumour cells, may enable antitumour T-cell responses and tumour destruction without causing harm to healthy tissues. Currently, neoantigens can be identified in tumour clinical samples by using genomic-based computational tools. The two main treatment modalities targeting neoantigens that have been investigated in clinical trials are personalised vaccines and tumour infiltrating lymphocytes-based adoptive T-cell therapy. In this mini review, we discuss the promises and challenges for using neoantigens as emergent targets to personalise and guide cancer immunotherapy in a broader set of cancers.
Project description:Currently, the programmed death-1/programmed death ligand-1 and the cytotoxic T-lymphocyte-associated protein 4 are the two commonly targeted immune-checkpoint inhibition pathways. These drugs have significantly improved the prognosis of many cancer types. While immune-checkpoint inhibitors have revolutionised the treatment of many cancer types, the majority of patients still progress. Several treatment strategies have been pursued to improve current results. One approach is to combine two checkpoint inhibitors, currently with promising results in melanoma, renal cell carcinoma and a subset of non-small-cell lung cancer patients. The identification of new checkpoint targets could allow the field of immuno-oncology to evolve further. We will discuss one of the most promising immune-checkpoint targets currently under investigation, the T-cell immunoglobulin and mucin domain-3.
Project description:Clinical progress in cancer immunotherapy has been slow; however, within the last 5 years, breakthrough successes have brought immunotherapy to the forefront in cancer therapy. Promising results have been observed in solid tumors and hematologic malignancies. Most treatment modalities have shown limited efficacy as monotherapy. The complex nature of cancer and the immunosuppressive microenvironment emphasizes the need to personalize immunotherapy by manipulating the patient's own immune system. For successful and long-lasting cure of cancer, a multimodal approach is essential, combining antitumor cell therapy with manipulation of multiple pathways in the tumor microenvironment to ameliorate tumor-induced immunosuppression.