Role Of Immune Checkpoint Blockade Research Articles

P2.04-002 CASPIAN: Phase 3 Study of First-Line Durvalumab ± Tremelimumab + Platinum-Based Chemotherapy vs Chemotherapy Alone in ED-SCLC

New therapies are urgently needed for patients with extensive-disease small cell lung cancer (ED-SCLC). High mutation burden in SCLC suggests a potential role for immune checkpoint blockade. Durvalumab is a selective, high-affinity, engineered human IgG1 mAb that blocks PD-L1 binding to PD-1 and CD80. Tremelimumab is a selective human IgG2 mAb against CTLA-4. Durvalumab ± tremelimumab in combination with chemotherapy has shown acceptable tolerability and evidence of clinical activity in a Phase 1b study (NCT02537418) in patients with advanced solid tumors, including NSCLC and SCLC.

DNA Damage and Repair Biomarkers of Immunotherapy Response.

DNA-damaging agents are widely used in clinical oncology and exploit deficiencies in tumor DNA repair. Given the expanding role of immune checkpoint blockade as a therapeutic strategy, the interaction of tumor DNA damage with the immune system has recently come into focus, and it is now clear that the tumor DNA repair landscape has an important role in driving response to immune checkpoint blockade. Here, we summarize the mechanisms by which DNA damage and genomic instability have been found to shape the antitumor immune response and describe clinical efforts to use DNA repair biomarkers to guide use of immune-directed therapies.Significance: Only a subset of patients respond to immune checkpoint blockade, and reliable predictive biomarkers of response are needed to guide therapy decisions. DNA repair deficiency is common among tumors, and emerging experimental and clinical evidence suggests that features of genomic instability are associated with response to immune-directed therapies. Cancer Discov; 7(7); 675-93. ©2017 AACR.

Immune Checkpoint Blockade in Breast Cancer Therapy.

Cancer immunotherapy is emerging as the most promising novel strategy for cancer treatment. Cancer immunotherapy is broadly categorized into three forms: immune checkpoint modulation, adoptive cell transfer, and cancer vaccine. Immune checkpoint blockade is demonstrated as the most clinically effective treatment with low immune-related adverse events (irAE). Blockade of PD-1/PD-L1 and CTLA-4 has achieved remarkable success in treating various types of tumors, which sparks great interests in this therapeutic strategy and expands the role of immune checkpoint blockade in treating tumors including breast cancer. Based on the notable results obtained from clinical trials, the United States' Food and Drug Administration (FDA) has approved multiple CTLA-4 monoclonal antibodies as well as the PD-1/PD-L1 monoclonal antibodies for treatment of different types of tumors. The theories of immunoediting, T-cell exhaustions, and co-stimulatory/co-inhibitory pathways are immunological foundations for immune checkpoint blockade therapy. Breast cancers such as triple negative breast cancer and HER-2 negative breast cancer respond to immune checkpoint blockade therapy due to their high immunogenicity. PD-1/PD-L1 blockade has just received FDA approval as a standard cancer therapy for solid tumors such as breast cancer. Development of immune checkpoint blockade focuses on two directions: one is to identify proper biomarkers of immune checkpoint blockade in breast cancer, and the other is to combine therapies with PD-1/PD-L1 blockade antibodies to achieve optimal clinical outcomes.

Inhibiting Immune Checkpoints for the Treatment of Bladder Cancer

Background:Increasing evidence supporting the role of immune checkpoint blockade in cancer management has been bolstered by recent reports demonstrating significant and durable clinical responses across multiple tumour types, including metastatic urothelial carcinoma (mUC). The majority of these results are achieved via blockade of the programmed death (PD) axis, which like CTLA-4 blockade permits T-cell activation and immune-mediated anti-tumour activity- essentially harnessing the patient’s own immune system to mount an anti-neoplastic response. However, while clinical responses can be striking, our understanding of the biology of immune checkpoint blockade is only beginning to shed light on how to maximize and even improve patient outcomes with immune checkpoint blockade, especially in UC.Methods:We performed a literature review for immune checkpoint blockade with a focus on rationale for checkpoint therapy and outcomes in UC. We also highlight the advances made in other tumour types, with a focus on the recent 2015 meeting of the American Society for Clinical Oncology.Results:In heavily pre-treated UC, trials are suggesting objective response rates above 30% . These impressive results are seen across multiple different tumour types, especially those with high burden of DNA level mutations. Identification of prognostic biomarkers is currently under investigation, in order to improve patient selection. Interestingly, response to PD-1 directed therapy is seen even in patients with no evidence of PD-1 positivity on immunohistochemistry. This has led to the development of enhanced biomarkers including assessing DNA mutation rates and immune gene signatures, to improve patient selection.Conclusions:Immune checkpoint blockade is an exciting cancer treatment modality which is demonstrating impressive clinical results across multiple tumour types. For UC, anti-PD directed therapy represents a much needed treatment in the metastatic, post chemotherapy context. Potential for these agents to have clinical utility in non-metastatic UC is still to be assessed.

Abstract A12: PDL-1 blockade and Sunitinib enhance the efficiency of oncolytic viral therapy

Abstract Purpose: Oncolytic viruses (OV) are attractive for use against multiple tumours given their ability to prime therapeutic immune responses in addition to their direct cytotoxic effects. We investigated the utility of reovirus, an OV currently in phase III clinical trials, as a novel immunotherapeutic against renal cell (RCC), non small cell lung (NSCLC) and breast carcinomas (BrCa) as both a monotherapy and in combination with sunitinib, a first line metastatic RCC agent. In addition the utility of adding an immune checkpoint inhibitor was investigated. Experimental Design: In-vitro, cytotoxicity, viral replication and chemokine production were assessed in a panel of human and murine cancer cell lines following exposure to reovirus, sunitinib or their combination. In-vivo, RENCA (murine renal cell carcinoma) cells were implanted subcutaneously into female balb/c mice to establish a syngeneic immunocompetent model of RCC. Tumor growth and overall survival were assessed following treatment with reovirus, sunitinib or their combination. IFN-γ, myeloid-derived suppressor cells (MDSC), and protective immunity were assessed by ELISA, flow cytometry (Gr1+/CD11b+) and adoptive transfer experiments, respectively. PDL-1 and PD-1 expression on both tumour and immune cells were assayed. Results: In vitro, exposure of RCC cell lines to reovirus resulted in an inflammatory cytotoxic response that was augmented through combination with sunitinib. In vivo, reovirus significantly reduced RENCA tumor burden and generated an anti-tumor immune response that was augmented by sunitinib. Combinations with sunitinib also lead to a decrease in myeloid-derived suppressor cells (MDSC) and resulted in improved overall survival and enhanced protective immunity. Preliminary results in NSCLC and BrCa are suggestive that this strategy maybe applicable to many cancer histologies. Both PDL-1 and PD-1 expression were up regulated by RV (similar to IFN gamma) in the majority of cell lines tested suggesting a potential role for checkpoint blockade (CB). Conclusions: Reovirus has both direct oncolytic and immunotherapeutic activity against RCC, which is augmented through combination with sunitinib. The role of immune CB is ongoing. These proof-of-principle investigations provide clear rationale to investigate RV/sunitinib/immune CB as a promising approach for early phase clinical trials as a novel treatment strategy for cancer. Citation Format: Ahmed Mostafa, Kathy Gratton, Keith A. Lawson, Zhong-Qiao Shi, Chandini Thirukkumaran, Don G. Morris. PDL-1 blockade and Sunitinib enhance the efficiency of oncolytic viral therapy. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A12.

Advances in the management of gastrointestinal cancers--an upcoming role of immune checkpoint blockade.

Gastrointestinal cancers are a group of highly aggressive malignancies, and novel therapeutic strategies with higher clinical efficacy are being actively sought. ‘Immunotherapy’ is now emerging as one such promising strategy for the treatment of these tumors. This article briefly reviews the recent advances that utilize targeting of immune checkpoint pathways, in the management of gastrointestinal malignancies.

Immunotherapy for advanced gastric and esophageal cancer: preclinical rationale and ongoing clinical investigations.

Gastric and esophageal cancers represent a major global cancer burden and novel approaches are needed. Despite recent improvements in outcomes with trastuzumab and ramucirumab the prognosis for advanced disease remains poor, with a median overall survival of 1 year. Comprehensive genomic characterization has defined molecular subgroups and potentially actionable genomic alterations, but the majority of patients do not yet benefit from molecularly directed therapies. Breakthroughs in immune checkpoint blockade have provided new therapeutic avenues in melanoma, and continue to expand into other tumor types, with ongoing investigations in gastrointestinal (GI) malignancies. The frequency of programmed death ligand 1 (PD-L1) overexpression, a putative response biomarker, approaches forty percent in gastric cancers. Translational studies and molecular classification suggest gastric and esophageal cancers are candidate malignancies for immune checkpoint inhibition trials and early clinical data is promising. Here we review the mechanisms, preclinical, and early clinical data supporting the role for immune checkpoint blockade in gastric and esophageal cancer.

Is there a role for immune checkpoint blockade in metastatic uveal melanoma?

Uveal melanoma is the most common intraocular malignancy in adults with a disease specific mortality rate of ~40%. Oncogenic mutations in GNAQ and GNA11 were recently identified as driver mutations in ~90% of uveal melanoma. While localized disease can be effectively treated by surgery or radiotherapy, treatment options for metastatic uveal melanoma are limited. To investigate the interplay between uveal melanoma and the hosts´ immune system and to test immunotherapeutic approaches, we have established an syngenic mouse model of GNAQ oncogene-driven melanoma.

Is there a role for immune checkpoint blockade with ipilimumab in prostate cancer?

Treatment for advanced prostate cancer has and will continue to grow increasingly complex, owing to the introduction of multiple new therapeutic approaches with the potential to substantially improve outcomes for this disease. Agents that modulate the patient's immune system to fight prostate cancer – immunotherapeutics – are among the most exciting of these new approaches. The addition of antigen-specific immunotherapy to the treatment of castration-resistant prostate cancer (CRPC) has paved the way for additional research that seeks to augment the activity of the immune system itself. The monoclonal antibody ipilimumab, approved in over 40 countries to treat advanced melanoma and currently under phase 2 and 3 investigation in prostate cancer, is thought to act by augmenting immune responses to tumors through blockade of cytotoxic T-lymphocyte antigen 4, an inhibitory immune checkpoint molecule. Ipilimumab has been studied in seven phase 1 and 2 clinical trials that evaluated various doses, schedules, and combinations across the spectrum of patients with advanced prostate cancer. The CRPC studies of ipilimumab to date suggest that the agent is active in prostate cancer as monotherapy or in combination with radiotherapy, docetaxel, or other immunotherapeutics, and that the adverse event profile is as expected given the safety data in advanced melanoma. The ongoing phase 3 program will further characterize the risk/benefit profile of ipilimumab in chemotherapy-naïve and -pretreated CRPC.

Combining immunological and androgen-directed approaches

The autologous antigen-presenting cell immunotherapy, sipuleucel-T, was the first and remains the only US Food and Drug Administration-approved immunotherapy for prostate cancer. In this article, we will summarize recent clinical data on several additional immune-directed strategies, some of which have now entered phase 3 trials. Multiple studies are now testing sipuleucel-T in different disease settings and/or in combination with conventional and novel hormonal therapies. In addition, a poxviral-based vaccine has shown promise in early-phase clinical studies and has now entered phase 3 testing in men with metastatic prostate cancer. Next, a DNA vaccine has been evaluated in men with biochemically recurrent prostate cancer and has shown early signs of clinical efficacy. Finally, several studies are evaluating the role of immune checkpoint blockade using ipilimumab in pivotal phase 3 trials in prostate cancer patients with advanced disease, as well as in earlier phase studies in combination with androgen ablation. The abundance of new treatment options for men with advanced prostate cancer will challenge the role of immunotherapy in these patients. Future progress may rely on optimal combination and sequencing of various immunotherapies with androgen-directed approaches as well as with other standard prostate cancer therapies, an effort which is now just beginning.