31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016): late breaking abstracts

Immuno-Oncology: New Insights into Targets and Therapies

The role of immunotherapy in the care of surgical oncology patients promises to expand as investigators and clinicians evaluate new targets and approaches. Currently active clinical trials evaluate new immune checkpoints, including lymphocyte activation gene 3, T cell immunoreceptor with Ig and ITIM domains, and killer Ig-like receptor 2DL1/2L3. Vaccines delivered through mRNA have demonstrated exciting results in early clinical trials and hold promise for expanded application. Investigational approaches include dendritic cell vaccines, peptide vaccines, cytokines therapies, and cellular therapies. These studies have the potential to revolutionize the management of surgical oncology patients and promote durable cures following surgical resection.

Intratumoral Versus Circulating Lymphoid Cells as Predictive Biomarkers in Lung Cancer Patients Treated with Immune Checkpoint Inhibitors: Is the Easiest Path the Best One?

The molecular and cell determinants that modulate immune checkpoint (ICI) efficacy in lung cancer are still not well understood. However, there is a necessity to select those patients that will most benefit from these new treatments. Recent studies suggest the presence and/or the relative balance of specific lymphoid cells in the tumor microenvironment (TEM) including the T cell (activated, memory, and regulatory) and NK cell (CD56dim/bright) subsets, and correlate with a better response to ICI. The analyses of these cell subsets in peripheral blood, as a more accessible and homogeneous sample, might facilitate clinical decisions concerning fast prediction of ICI efficacy. Despite recent studies suggesting that lymphoid circulating cells might correlate with ICI efficacy and toxicity, more analyses and investigation are required to confirm if circulating lymphoid cells are a relevant picture of the lung TME and could be instrumental as ICI response biomarkers. This short review is aimed to discuss the recent advances in this fast-growing field.

Urothelial cancer: a narrative review of the role of novel immunotherapeutic agents with particular reference to the management of non-muscle-invasive disease

AIM

This narrative review describes current guidelines for treating NMIBC, provides an overview of the principle behind immune checkpoint inhibition, and summarizes current evidence for checkpoint inhibitors in urothelial malignancy. Further, we discuss potential strategies for immune checkpoint inhibition in the management of NMIBC.

BACKGROUND

Adjuvant intravesical BCG immunotherapy has been the mainstay of treatment for high-risk non-muscle-invasive bladder cancer (NMIBC) for decades but is associated with both a significant side effect profile and failure rate. Recently, a substantial body of trial data has been published demonstrating the successful use of systemic immunotherapy in the treatment of advanced urothelial malignancy and, in particular, a class of drugs known as 'immune checkpoint inhibitors'. This has led to the approval of a number of these drugs by the UK National Institute of Health and Care Excellence and the US Food and Drug Administration, and ongoing trials are examining use in the management of NMIBC.

METHODS

To identify relevant published data, using the PubMed/ Medline search engine, an online search of the Pubmed/ Medline archives was conducted using the terms bladder cancer' in combination with 'checkpoint inhibitors', and limited to articles in English published between 1966 and September 2017.To identify ongoing trials of interest but not yet published, a further search of the clinical trials.gov search engine was conducted using the term 'non-muscle-invasive bladder cancer'.

CONCLUSION

There has been little advance in available adjuvant therapy for NMIBC treated with TURBT. Current intravesical therapies are associated with a high recurrence rate and significant side effect profile. The impending publication of the wealth of ongoing trials, both into the delivery and efficacy of checkpoint inhibition will direct the future treatment of NMIBC.

Rational combination of cancer immunotherapy in melanoma

The recent advances in cancer immunotherapy with unprecedented success in therapy of advanced melanoma represent a turning point in the landscape of melanoma treatment. Given the complexity of activation of immunological system and the physiologic multifactorial homeostatic mechanisms controlling immune responses, combinatorial strategies are eagerly needed in melanoma therapy. Nevertheless, rational selection of immunotherapy combinations should be more biomarker-guided, including not only the cancer immunogram, PD-L1 expression, interferon gene expression signature, mutational burden, and tumor infiltration by CD8+ T cells but also intratumoral T cell exhaustion and microbiota composition. In this review, we summarize the rationale to develop combination treatment strategies in melanoma and discuss biological background that could help to design new combinations in order to improve patients' outcome.

Predictive biomarkers of response for immune checkpoint inhibitors in non-small-cell lung cancer

Immune checkpoint blockade has been a pivotal development in the management of advanced non-small-cell lung cancer (NSCLC). Although durable antitumour activity and improved survival have been observed in a subset of patients, there is a need for additional predictive biomarkers to improve patient selection and avoid toxicity in potential non-responders. This review will address the use and limitations of tumour programmed death-ligand 1 expression as a predictive biomarker and review emerging biomarker strategies specifically related to NSCLC including genetic alterations (tumour mutation burden, loss and gain activated mutations), tumour-related factors (tumour microenvironment) and factors related to the host immune system. Novel approaches in biomarker detection such as peripheral blood monitoring will also be reviewed.

Prognostic implication of programmed cell death 1 protein and its ligand expressions in endometrial cancer

OBJECTIVE

Monoclonal antibodies targeting programmed cell death-1 (PD-1)/programmed death ligand 1 (PD-L1) demonstrated promising clinical response. The predictive/prognostic value of PD-1/PD-L1 immunohistochemistry (IHC) has been evaluated in many cancer types. However, the prognostic value of PD-1/PD-L1 IHC has not been evaluated in endometrial cancer.

METHODS

We conducted a retrospective study to quantify the IHC CD8, PD-1, and PD-L1 expressions in immune cells at center of tumor (CT), invasive margin (IM), and/or tumor cell in 183 primary endometrial cancer samples from a single cohort, followed by their reciprocal combinations, including compartmental differences, and correlated them with overall survival (OS) and progression-free survival (PFS).

RESULTS

In repeated Cox multivariable models adjusted by clinicoimmunopathologic factors, high CT-PD-L1 was an independent adverse prognostic factor for PFS in all patients and in the microsatellite-stable subgroup. Immune marker ratios revealed independently shorter PFS for high CT-PD-L1/CT-CD8 and CT-PD-L1/CT-PD-1 ratios. Classification of endometrial cancer into four groups based on CT-CD8 and CT-PD-L1 revealed significantly different survival among groups.

CONCLUSIONS

The high PD-L1/CD8 ratio and the high expression of PD-L1 on immune cells were independent poor prognostic factors for PFS in endometrial cancer, providing insights into the tumor microenvironment.

Measuring multiple parameters of CD8+ tumor-infiltrating lymphocytes in human cancers by image analysis

BACKGROUND

Immuno-oncology and cancer immunotherapies are areas of intense research. The numbers and locations of CD8+ tumor-infiltrating lymphocytes (TILs) are important measures of the immune response to cancer with prognostic, pharmacodynamic, and predictive potential. We describe the development, validation, and application of advanced image analysis methods to characterize multiple immunohistochemistry-derived CD8 parameters in clinical and nonclinical tumor tissues.

METHODS

Commercial resection tumors from nine cancer types, and paired screening/on-drug biopsies of non-small-cell lung carcinoma (NSCLC) patients enrolled in a phase 1/2 clinical trial investigating the PD-L1 antibody therapy durvalumab (NCT01693562), were immunostained for CD8. Additional NCT01693562 samples were immunostained with a CD8/PD-L1 dual immunohistochemistry assay. Whole-slide scanning was performed, tumor regions were annotated by a pathologist, and images were analyzed with customized algorithms using Definiens Developer XD software. Validation of image analysis data used cell-by-cell comparison to pathologist scoring across a range of CD8+ TIL densities of all nine cancers, relying primarily on 95% confidence in having at least moderate agreement regarding Lin concordance correlation coefficient (CCC = 0.88-0.99, CCC_lower = 0.65-0.96).

RESULTS

We found substantial variability in CD8+ TILs between individual patients and across the nine types of human cancer. Diffuse large B-cell lymphoma had several-fold more CD8+ TILs than some other cancers. TIL densities were significantly higher in the invasive margin versus tumor center for carcinomas of head and neck, kidney and pancreas, and NSCLC; the reverse was true only for prostate cancer. In paired patient biopsies, there were significantly increased CD8+ TILs 6 weeks after onset of durvalumab therapy (mean of 365 cells/mm2 over baseline; P = 0.009), consistent with immune activation. Image analysis accurately enumerated CD8+ TILs in PD-L1+ regions of lung tumors using the dual assay and also measured elongate CD8+ lymphocytes which constituted a fraction of overall TILs.

CONCLUSIONS

Validated image analysis accurately enumerates CD8+ TILs, permitting comparisons of CD8 parameters among tumor regions, individual patients, and cancer types. It also enables the more complex digital solutions needed to better understand cancer immunity, like analysis of multiplex immunohistochemistry and spatial evaluation of the various components comprising the tumor microenvironment.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01693562 . Study code: CD-ON-MEDI4736-1108. Interventional study (ongoing but not currently recruiting). Actual study start date: August 29, 2012. Primary completion date: June 23, 2017 (final data collection date for primary outcome measure).

New Strategies Using Antibody Combinations to Increase Cancer Treatment Effectiveness

Antibodies have proven their high value in antitumor therapy over the last two decades. They are currently being used as the first-choice to treat some of the most frequent metastatic cancers, like HER2⁺ breast cancers or colorectal cancers, currently treated with trastuzumab (Herceptin) and bevacizumab (Avastin), respectively. The impressive therapeutic success of antibodies inhibiting immune checkpoints has extended the use of therapeutic antibodies to previously unanticipated tumor types. These anti-immune checkpoint antibodies allowed the cure of patients devoid of other therapeutic options, through the recovery of the patient’s own immune response against the tumor. In this review, we describe how the antibody-based therapies will evolve, including the use of antibodies in combinations, their main characteristics, advantages, and how they could contribute to significantly increase the chances of success in cancer therapy. Indeed, novel combinations will consist of mixtures of antibodies against either different epitopes of the same molecule or different targets on the same tumor cell; bispecific or multispecific antibodies able of simultaneously binding tumor cells, immune cells or extracellular molecules; immunomodulatory antibodies; antibody-based molecules, including fusion proteins between a ligand or a receptor domain and the IgG Fab or Fc fragments; autologous or heterologous cells; and different formats of vaccines. Through complementary mechanisms of action, these combinations could contribute to elude the current limitations of a single antibody which recognizes only one particular epitope. These combinations may allow the simultaneous attack of the cancer cells by using the help of the own immune cells and exerting wider therapeutic effects, based on a more specific, fast, and robust response, trying to mimic the action of the immune system.

Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of bladder carcinoma

The standard of care for most patients with non-muscle-invasive bladder cancer (NMIBC) is immunotherapy with intravesical Bacillus Calmette-Guérin (BCG), which activates the immune system to recognize and destroy malignant cells and has demonstrated durable clinical benefit. Urologic best-practice guidelines and consensus reports have been developed and strengthened based on data on the timing, dose, and duration of therapy from randomized clinical trials, as well as by critical evaluation of criteria for progression. However, these reports have not penetrated the community, and many patients do not receive appropriate therapy. Additionally, several immune checkpoint inhibitors have recently been approved for treatment of metastatic disease. The approval of immune checkpoint blockade for patients with platinum-resistant or -ineligible metastatic bladder cancer has led to considerations of expanded use for both advanced and, potentially, localized disease. To address these issues and others surrounding the appropriate use of immunotherapy for the treatment of bladder cancer, the Society for Immunotherapy of Cancer (SITC) convened a Task Force of experts, including physicians, patient advocates, and nurses, to address issues related to patient selection, toxicity management, clinical endpoints, as well as the combination and sequencing of therapies. Following the standard approach established by the Society for other cancers, a systematic literature review and analysis of data, combined with consensus voting was used to generate guidelines. Here, we provide a consensus statement for the use of immunotherapy in patients with bladder cancer, with plans to update these recommendations as the field progresses.