Highlights from SITC's 31st Annual Meeting & Associated Programs

The Society for Immunotherapy of Cancer’s (SITC) Annual Meeting is the largest meeting dedicated solely to the field of cancer immunotherapy. In line with SITC’s goal of improving outcomes for patients with cancer, SITC’s 31st Annual Meeting (SITC 2016; November 9-13, 2016; National Harbor, Maryland) brought together leading cancer immunotherapy experts to discuss research and clinical practice, and national and international initiatives. This article summarizes some key highlights from SITC 2016.

SITC 2016 ASSOCIATED PROGRAMS

New Cancer Immunotherapy Agents in Development

This dynamic program featured rapid-fire presentations on novel immunotherapeutic strategies. Combination immunotherapy approaches, especially those including immune checkpoint blockade, dominated both the clinical and preclinical sessions. The importance of understanding the mechanistic basis for the clinical efficacy of particular combination strategies was emphasized, and optimization of the drug development process and integration of biomarkers into clinical decision making were also identified as critical to ensuring that only the most promising trials are selected to move forward.

Primer on Tumor Immunology and Cancer Immunotherapy^TM

The development of novel immune-based cancer treatment options is the result of a dramatic increase in our understanding of tumor immunology. This 1-day educational program provided a foundation in core immunology principles for students and postdoctoral fellows, and provided more senior physicians and scientists with the opportunity to solidify their understanding of immuno-oncology as it relates to basic and clinical research in cancer immunotherapy.

Workshop on Challenges, Insights, and Future Directions for Mouse and Humanized Models in Cancer Immunology and Immunotherapy Disease models are important tools to inform the future of immune drug development and aid our understanding of the mechanisms underlying antitumor immune responses. This workshop provided a comprehensive discussion on the strengths and weaknesses of a variety of models, approaches toward improving the predictive value of mouse models, and anticipated advances in cancer modeling, with a focus on how to accurately model the tumor immune microenvironment.

SITC 2016 31ST ANNUAL MEETING

Presented by leaders in the field, this year’s plenary sessions addressed topics central to progress in tumor immunology and cancer immunotherapy, including the tumor microenvironment, state-of-the-art immunotherapies, the future of combination immunotherapy, and high-priority agents under investigation in the Cancer Immunotherapy Trials Network (CITN). In addition, the 31st Annual Meeting featured a number of thought-provoking concurrent sessions, 2 of which were interdisciplinary programs organized in collaboration with the American Society for Cell Biology and the Society of Behavioral Medicine.

Value of Cancer Immunotherapy Summit

Building on the success of the SITC 2015 Value of Cancer Immunotherapy Session, this half-day program, which was organized in collaboration with the American Society of Clinical Oncology, united experts in cancer immunotherapy with key stakeholders in the healthcare system, and also provided a patient perspective. Presenters emphasized that the unique aspects of immune-based agents will affect the real value of these therapies and helped prioritize the direction of future discussions on the value of cancer immunotherapy. Based on the outcomes of this summit, SITC will continue its efforts to optimize the value framework for cancer therapeutics to ensure patients have access to high-quality, cost-effective care.

Late-Breaking Abstracts

Abstracts featuring cutting-edge data from basic and translational research, clinical trials, and aspects of clinical management were presented throughout the meeting. Some of the most novel and practice-changing clinical trials are highlighted below.

In a highly anticipated presentation, Joaquim Bellmunt, MD, PhD, of Dana-Farber/Brigham and Women’s Cancer Center, shared data on the effects of pembrolizumab (Keytruda) versus investigators’ choice of standard chemotherapy agents for the treatment of advanced bladder cancer. This international study reported significantly longer overall survival in patients treated with pembrolizumab (HR, 0.73; P = .0022; median 10.3 vs 7.4 months), and this was seen across all PD-L1 populations. This study was halted prematurely due to the markedly superior response in patients treated with pembrolizumab and is noteworthy in being the first in almost 20 years to demonstrate improved overall survival for patients with advanced bladder cancer.

Interim data from a multicenter phase I/II trial investigating 2 dose schedules of ipilimumab (Yervoy) and nivolumab (Opdivo; 1 mg/3 mg vs 3 mg/1 mg) in patients with advanced or metastatic urothelial cancer that progressed after chemotherapy were presented by Padmanee Sharma, MD, PhD, of The University of Texas MD Anderson Cancer Center. Patients in the nivolumab 1/ ipilimumab 3 arm had an objective response rate (ORR) of 38.5%, while ORR in the nivolumab 3/ipilimumab 1 and nivolumab monotherapy arms were 26.0% and 25.5%, respectively. Median overall survival was also higher in the nivolumab 1/ipilimumab 3 group (10.2 months [95% CI, 4.5-not reached]) than the nivolumab 3/ipilimumab 1 group (7.3 months [95% CI, 5.6-11.4]). Side effects in the combination treatment groups were similar to those observed in other studies. These results support further development of the nivolumab 1/ipilimumab 3 combination for treatment of metastatic urothelial cancer.

John Hunter, PhD, of Compugen Inc, presented findings from an international study that used proprietary computational algorithms to identify a potential new T-cell checkpoint, PVRIG. PVRIG is a member of the TIGIT molecular family that is expressed on T cells and NK cells. The Compugen group also developed an anti- body specific for PVRIG, which enhanced CD4+ and CD8+ T cell proliferation in vitro and significantly reduced tumor growth when combined with anti—PD-1 therapy growth (P = .0005; 56% tumor growth inhibition) in vivo. New immunotherapeutic targets, such as PVRIG, that can be used in combination might help expand the proportion of patients who respond to treatment with immune checkpoint inhibitors.

SITC Initiatives: Updates From the Immune Biomarkers Task Force and Immunoscore Validation Project

SITC President and Immune Biomarkers Task Force Chair Lisa Butterfield, PhD, of the University of Pittsburgh, reported recent progress from the SITC Immune Biomarkers Task Force, which was established to address novel topics in the field, including technologies and high-throughput approaches, novel and conventional agents affecting immunity, bioinformatics, complex data analysis, and advances in biological sampling. From 2015 to 2016, 4 working groups (WGs) sought to address challenges barring progress in the field. In this ongoing effort, these WGs have generated 5 white papers and led a dedicated workshop, Immunotherapy Biomarkers 2016: Overcoming the Barriers, held in collaboration with the National Institutes of Health. In addition, the WGs also authored 12 short reports highlighting novel technologies used for biomarker development in a series published in the Journal for Immunotherapy of Cancer.

As an update to the results presented at ASCO 2016, Jérôme Galon, PhD, of INSERM, presented the latest results of the SITC Immunoscore Validation Project, a SITC-led international effort to validate the Immunoscore, which is a standardized immunohisto-chemistry-based assay to measure the immune contexture in and around tumors. As presented previously, the primary objective of this study in patients with stage I-III colon cancer was reached; Immunoscore high versus low predicted time to recurrence in each of the separate groups examined. New data were also presented, in which Immunoscore was predictive of overall and disease-free survival independent of MSI status (high vs low). These findings illustrate the prognostic value of Immunoscore and justify the use of immune parameters as a new component of cancer classification.