Immune-related Response Research Articles

Scoop: Multicenter phase I/II trial of BBI608 and pembrolizumab in patients with metastatic colorectal cancer (EPOC1503).

107 Background: The anti–PD-1 antibody pembrolizumab (P) provides response rates of 28-57% in patients (pts) with MSI-H metastatic colorectal cancer (mCRC) vs 0% in those with non-MSI-H cancers. STAT3 has been previously reported as a potential key driver of immune evasion. This study investigates efficacy and safety for the combination of BBI608 (napabucasin), which blocks phosphorylated STAT3 and downregulates IDO1 and PD-L1, with P, in pts with mCRC. BBI608 480 mg BID with P was determined as the recommended phase II dose in phase I. Methods: Phase II included Cohorts A (MSI-H) and B (non-MSI-H). Pts with mCRC not responding to or intolerant of standard chemotherapies were enrolled. The primary endpoint was immune-related objective response rate (irORR), according to irRECIST. The sample size for Cohort A (10 pts) was derived in an exploratory manner. In Cohort B, assuming null and alternative hypotheses of irORR = 5% and 20% led to an estimated required sample size of 40 pts, with a 1-sided alpha of 5% and power of 90%. Genomic profiles and the consensus molecular subtypes (CMS) of colorectal cancer were determined by whole exome sequencing and RNA sequencing as previously described. Results: From Feb/2017 to Jun/2018, 10 pts were enrolled in Cohort A and 40 in Cohort B. The irORR was 50% (5 of 10 pts) in Cohort A and 10% (95% CI 2.8 to 23.7) (4 of 40 pts) in Cohort B. Of evaluable 19 pts for CMS classification in Cohort B, CMS1, CMS2, CMS3, and CMS4 were detected in 3, 6, 4, and 6 cases, respectively. The irORR was 33% (1 of 3 pts), 0% (0 of 6 pts), 25% (1 of 4 pts), 33% (2 of 6 pts) in CMS1, CMS2, CMS3, and CMS4, respectively. One CMS3 patient with partial response had POLE mutation, while 1 CMS1 and 2 CMS4 pts with partial response did not. The most common grade 3 or higher treatment-related adverse events included fever (10%) in Cohort A, and diarrhea (5%) and appetite loss (7.5%) in Cohort B, without unexpected safety signals. No treatment-related deaths occurred. Conclusions: BBI608 with P showed encouraging anti-tumor activity with acceptable toxicity for non-MSI-H mCRC pts as well as MSI-H mCRC pts. Impact of CMS on the efficacies of this combination warrants further investigation in the additional cohort of this study. Clinical trial information: NCT02851004.

Pan-Tumor Pathologic Scoring of Response to PD-(L)1 Blockade.

Pathologic response assessment of tumor specimens from patients receiving systemic treatment provides an early indication of therapeutic efficacy and predicts long-term survival. Grading systems for pathologic response were first developed for chemotherapy in select tumor types. Immunotherapeutic agents have a mechanism of action distinct from chemotherapy and are being used across a broad array of tumor types. A standardized, universal scoring system for pathologic response that encompasses features characteristic for immunotherapy and spans tumor types is needed. Hematoxylin and eosin-stained slides from neoadjuvant surgical resections and on-treatment biopsies were assessed for features of immune-related pathologic response (irPR). A total of 258 specimens from patients with 11 tumor types as part of ongoing clinical trials for anti-PD-(L)1 were evaluated. An additional 98 specimens from patients receiving anti-PD-(L)1 in combination with other treatments were also reviewed, including those from three additional tumor types. Common irPR features (immune activation, cell death, tissue repair, and regression bed) were present in all tumor types reviewed, including melanoma, non-small cell lung, head and neck squamous cell, Merkel cell, and renal cell carcinoma, among others. Features were consistent across primary tumors, lymph nodes, and distant metastases. Specimens from patients treated with anti-PD-(L)1 in combination with another agent also exhibited irPR features. irPR features are consistent across tumor types and treatment settings. Standardized, pan-tumor irPR criteria (irPRC) are defined and associated specimen-handling considerations are described. Future, prospective studies are merited to validate irPRC in larger datasets and to associate pathologic features with long-term patient outcomes.

A phase II study of durvalumab (MEDI4736) (anti-PD-L1) and trametinib (MEKi) in microsatellite stable (MSS) metastatic colorectal cancer (mCRC).

152 Background: Monotherapy with immune checkpoint blockade (ICB) is ineffective for patients (pts) with MSS mCRC. Novel approaches to modulate the tumor microenvironment (TME) are needed. Here, we investigate whether the combination of trametinib (T) with durvalumab (D) can alter the immune TME by successfully priming and activating T-cells. Methods: An open-label, single center phase II trial with primary endpoint of immune-related response rate for T+D in refractory MSS mCRC pts (NCT03428126). T is 2mg/day orally starting 1 week prior to D, which is given 1500mg intravenously every 4 weeks. Dose de-escalation strategy performed to identify maximum tolerated dose (MTD). Simon 2-stage design utilized with plans to enroll 29 pts into the first stage, requiring response in 2 or more pts to proceed to stage 2 (n = 15). Results: Demographics for 29 treated pts: 48% female, median age 48 years (range 28-75), and median prior therapies was 2 (range 1-5). No grade (G) 4 treatment-related adverse events (TRAE). The most common G3 TRAE included autoimmune hepatitis (14%) and acneiform rash (10%). G1/2 TRAE included acneiform rash (69%), fatigue (24%) and anemia (21%). No fatal TRAE and 4 pts discontinued treatment due to TRAE. 1 of 29 pts had confirmed partial response (PR) lasting 9.3 months (mo) for an ORR of 3.4%. This pt had an ATM E221fs*14 mutation. 7 pts had stable disease (SD) with median time to progression (TTP) of 5.4 mo (range 3.9-9.3 mo). 1 pt remains on active therapy with SD ( > 10 mo). 5 pts (1 PR, 4 SD) demonstrated decrease in total CEA ng/mL (best percentage reduction: 94%, 95%, 42%, 34% and 21.6% respectively). Median TTP for the entire cohort was 3.2 mo (range 1.1-9.3 mo). Consensus molecular subtypes (CMS) were performed on the primary CRC in 23 pts: 12 CMS2, 2 CMS3, and 9 CMS4. 4 SD pts were CMS2, 1 SD pt was CMS4 and the CMS status of the pt with a PR was unknown. Conclusions: The combination of T+D did not meet efficacy criteria to proceed to the second stage of the study. Analysis of 15 paired on-treatment biopsies is ongoing and will be presented. Utilization of CMS characterization in mCRC clinical trials is feasible and may provide an improved biological understanding of treatment activity. Clinical trial information: NCT03428126.

Immunotherapy Outcomes in Advanced Melanoma in Relation to Age.

Older age is a melanoma risk factor. Elderly individuals are likelier to have immunosenescence, which could help melanoma cells escape immune surveillance. Hence, it is believed that elderly people cannot mount a potent immune response to checkpoint inhibitors to eliminate melanoma. To investigate age-related differences in the time to progression, overall survival, and immunotherapy-related adverse events among patients with metastatic melanoma who received checkpoint inhibitors. We retrospectively identified patients at our institution between January 2012 and December 2016 with stage IV melanoma who received at least 1 dose of ipilimumab, pembrolizumab, nivolumab, or combined ipilimumab and nivolumab. Demographic, pathologic, and clinical characteristics were obtained. Immune-related response criteria were used to define responses. Twenty-nine patients were younger than age 65 years and 31 were age 65 years or older. Time to progression was comparable between the age groups (hazard ratio = 0.79, 95% confidence interval = 0.37-1.70, p = 0.46). Overall survival was not significantly different after immunotherapy between groups (hazard ratio = 0.75, 95% confidence interval = 0.31-1.82, p = 0.491). Overall, immunotherapy-related adverse events were comparable between groups, with 62% in younger patients (18/29) and 45% in older patients (14/31 p = 0.19). Of 60 patients, 30 responded to immunotherapy. Nonresponders were more likely than responders to have BRAF-mutated melanomas (16 [53.3%] vs 8 [27.6%]; p = 0.04) and less likely to have immunotherapy-related adverse events (12 [40%] vs 20 [66.7%]; p = 0.04). Aging does not seem to affect response to checkpoint inhibitors. Elderly patients with metastatic melanoma should be treated similarly to younger patients.

Challenges in assessing solid tumor responses to immunotherapy.

With the advent of immunotherapy as an integral component of multidisciplinary solid tumor treatment, we are confronted by an unfamiliar and novel pattern of radiographic responses to treatment. Enlargement of tumors or even new lesions may not represent progression, but rather reflect what will ultimately evolve into a clinically beneficial response. In addition, the kinetics of radiographic changes in response to immunotherapy treatments may be distinct from what has been observed with cytotoxic chemotherapy and radiation. The phenomenon of pseudoprogression has been documented in patients receiving immunotherapeutic agents, such as checkpoint inhibitors and cellular therapies. Currently, there are no clinical response guidelines that adequately account for pseudoprogression and solid tumor responses to immunotherapy in general. Even so, response criteria have evolved to account for the radiographic manifestations of novel therapies. The evolution of World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), along with the emergence of immune-related response criteria (irRC) and the immune Response Evaluation Criteria in Solid Tumors (iRECIST) reflect the need for new frameworks. This review evaluates the relationship between pseudoprogression, clinical outcomes, and our current understanding of the biology of pseudoprogression. To achieve our goal, we discuss unusual response patterns in patients receiving immunotherapy. We seek to develop a deeper understanding of radiographic responses to immunotherapy such that clinical benefit is not underappreciated in individual patients and during clinical investigation.

Abstract B049: Hyperprogressive disease after two cycles of immunotherapy in HER-2 positive metastatic gastric cancer

Abstract Background: Recent advancements in immune checkpoint inhibitors (ICIs) have revolutionized treatment options in many solid cancers. Pembrolizumab and nivolumab, an anti-programmed death ligand 1 (anti PD-L1) agent, has approved in treatment of advanced or metastatic gastric cancer previously treated with two or more therapies. Although immunotherapy has shown durable response in selective patients, there are also growing evidences of hyperprogression (HPD) in a subset of patients treated with ICIs. Here, we report a patient who hyper-progressed after two cycles of pembrolizumab containing regimen. Methods: Based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, HPD is defined as time to treatment failure (TTF) <2 months and minimum increase of measurable lesions of 10mm plus one of the following: 1) increase of >40% of target lesion compared with baseline or 2) increase of >20% and appearance of multiple new lesions. Medical records of the patient were retrieved from electronic medical record (EMR). Tumor samples were obtained from stomach and liver before and after anti-PD1 treatment. Serial blood was collected to evaluate circulating tumor cells (CTC), targeted NGS of circulating free DNA (cfDNA) and immune phenotyping to identify possible underlying mechanism. To identify the mechanisms of HPD, Next-Generation Sequencing (NSG) of tissue and cfDNA of FoundationOne Liquid was utilized to analyze genomic alterations such as copy number alterations, rearrangements somatic mutations. Results: The 57 year old female, was initially diagnosed with HER2 positive advanced gastric cancer (AGC) with multiple liver metastases. Before treatment, immunohistochemistry (IHC) from stomach revealed amplification of human epidermal growth factor receptor 2 (HER2, ERbB2) with combined positive score (CPS) of 10% using PD-L1 IHC 22C3 pharmDx. She was then enrolled in the currently ongoing, investigator-initiated PANTHERA trial (NCT02901301), a phase Ib/II study of first line pembrolizumab in combination with trastuzumab, capecitabine and cisplatin. However, rapid progression was noted after two cycles. Target lesions increased by 27.1%, and several new liver metastasis as well as non-targetable lesions such as stomach and peritoneal seeding, increased. Tumor markers including CA 72-4, CA 125 and aFP also increased. Since the patient’s condition deteriorated rapidly, she was immediately started with a different chemotherapy and response evaluation with immune-related Response Evaluation Criteria in Solid Tumors (irRECIST) was not evaluated. IHC of re-biopsied stomach revealed that CPS was 30%. Notably, there were no differences in IHC of liver before and after treatment, which were both HER2 and CPS negative. Interestingly, baseline cfDNA analysis showed the amplification of EGFR, which were known to be related to HPD. Also, high level of TP53, APC mutations and Rb amplification were observed. CTC (EpCAM+CK+CD45) was initially 2 at baseline and increased to 7 after hyperprogression. Conclusion: Among 41 patients enrolled in ongoing PANTHERA trial, only one patient progressed after 2 cycles of treatment . To our knowledge, this is the first documented hyperprogression in advanced or metastatic gastric cancer after treatment with pembrolizumab. Although mechanisms behind HPD remain to be elucidated, the discrepancy in pre and post IHC results points out that tumor heterogeneity may play a role. NGS results and immune phenotyping results are pending. Citation Format: Jii Bum Lee, Garden Lee, Woo Sun Kwon, Jun Hyeok Heo, Seung-Hyun Jung, Yeun-Jun Chung, Beodul Kang, Hyo Song Kim, Hyun Cheol Chung, Sun Young Rha. Hyperprogressive disease after two cycles of immunotherapy in HER-2 positive metastatic gastric cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B049. doi:10.1158/1535-7163.TARG-19-B049

Impact of nitrite exposure on plasma biochemical parameters and immune-related responses in Takifugu rubripes

Nitrite is a major environmental pollutant in aquatic environments that negatively affects aquatic species. In this study, we investigated the impact of nitrite exposure on plasma biochemical parameters and immune responses in Takifugu rubripes. Fish were exposed to various concentrations of nitrite (0, 0.5, 1, 3, and 6 mM) for 96 h. After 0, 12, 24, 48, and 96 h of exposure, fish blood samples were collected to assay the levels of total protein (TP), albumin (Alb), glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (ALT), complement C3 (C3), complement C4 (C4), immunoglobulin (IgM), and lysozyme activity (LZM). The gills were sampled to analyze the mRNA levels of heat shock protein 70 (hsp70), heat shock protein 90 (hsp90), tumor necrosis factor α (tnf-α), B-cell activating factor (baff), interleukin-6 (il-6), and interleukin-12 (il-12). Levels of GOT, ALT, C3, and C4 were significantly enhanced in the high nitrite concentration group (3 and 6 mM), whereas those of TP, Alb, LZM, and IgM decreased significantly with the same treatments. Nitrite significantly upregulated hsp70, hsp90, tnf-α, il-6, il-12, and baff mRNA levels after 96 h of exposure. These results indicated that nitrite exposure altered the blood physiological status and immune system response, resulting in dysfunction and immunotoxicity in T. rubripes. Furthermore, our results reveal the possible mechanism of aquatic-nitrite-induced toxicity in fish.

Blood-derived dendritic cell vaccinations induce immune responses that correlate with clinical outcome in patients with chemo-naive castration-resistant prostate cancer

BackgroundClinical benefit of cellular immunotherapy has been shown in patients with castration-resistant prostate cancer (CRPC). We investigated the immunological response and clinical outcome of vaccination with blood-derived CD1c+ myeloid dendritic cells (mDCs; cDC2) and plasmacytoid DCs (pDCs).MethodsIn this randomized phase IIa trial, 21 chemo-naive CRPC patients received maximally 9 vaccinations with mature mDCs, pDCs or a combination of mDCs plus pDCs. DCs were stimulated with protamine/mRNA and loaded with tumor-associated antigens NY-ESO-1, MAGE-C2 and MUC1. Primary endpoint was the immunological response after DC vaccination, which was monitored in peripheral blood and in T cell cultures of biopsies of post-treatment delayed-type hypersensitivity-skin tests. Main secondary endpoints were safety, feasibility, radiological PFS (rPFS) and overall survival. Radiological responses were assessed by MRIs and contrast-enhanced 68Ga-prostate-specific membrane antigen PET/CT, according to RECIST 1.1, PCWG2 criteria and immune-related response criteria.ResultsBoth tetramer/dextramer-positive (dm+) and IFN-γ-producing (IFN-γ+) antigen specific T cells were detected more frequently in skin biopsies of patients with radiological non-progressive disease (5/13 patients; 38%) compared to patients with progressive disease (0/8 patients; 0%). In these patients with vaccination enhanced dm+ and IFN-γ+ antigen-specific T cells median rPFS was 18.8 months (n = 5) vs. 5.1 months (n = 16) in patients without IFN-γ-producing antigen-specific T cells (p = 0.02). The overall median rPFS was 9.5 months. All DC vaccines were well tolerated with grade 1–2 toxicity.ConclusionsImmunotherapy with blood-derived DC subsets was feasible and safe and induced functional antigen-specific T cells. The presence of functional antigen-specific T cells correlated with an improved clinical outcome.Trial registrationClinicalTrials.gov identifier NCT02692976, registered 26 February 2016, retrospectively registered.

ATIM-04. PHASE I IMMUNOVIROTHERAPY TRIAL OF IL-12 EXPRESSING HSV-1 (M032) IN PET DOGS WITH SPONTANEOUS HIGH GRADE GLIOMAS: A PRELIMINARY REPORT

Abstract Malignant gliomas are the most common primary brain tumors in humans, accounting for approximately 30% of all primary central nervous system (CNS) tumors in adults. Incidence and outcomes of gliomas in pet dogs are similar to humans. Previous methods of studying gliomas in rodent models do not adequately represent several features that define human cancers, most notably the sporadic nature of tumor development. Murine models lack intra-tumoral heterogeneity or hosts do not have an intact immune system. To overcome these rodent model deficiencies, many investigators have used canine models to study human diseases. We describe a prospective, phase I clinical trial in canine patients with sporadic high-grade gliomas to evaluate M032, a mutant HSV-1 expressing IL-12, alone or combined with a checkpoint inhibitor (Indoximod) to assess safety, tolerability and efficacy. M032 has been shown to infect and kill glioma cells, producing a virus and tumor cell antigen-rich debris field; will provide an increased adjuvant effect from released viral DNA recognized by TLR-9 receptors; and express IL-12 locally, stimulating activation of TH1 lymphocytes. The intratumoral inflammatory cell infiltration is expected to result in immune-related anti-viral responses with cross-epitope spreading to tumor antigens. Indoximod immunomodulation will be tested in latter cohorts to prolong anti-tumor responses. To date, six canines with high-grade gliomas have received intratumoral M032 without virus-related toxicities. Resected tumor and serial blood samples are being cryopreserved for analysis of lymphoid and monocyte/myeloid subset markers. This same virus is being tested in a phase 1 clinical trial in humans with high-grade malignant gliomas; eight human patients have received treatment at this writing without virus-related toxicities. The concurrent prosecution of both trials allows unprecedented real time comparison of safety and efficacy of immunovirotherapy as a stringent test of suitability of the dog as a valid and informative model of human brain tumors.

Influence of immunomodulators on urological imaging

Immune checkpoint inhibitors (ICI) have led to great advances in the therapy of metastatic renal cell and urothelial carcinoma. Currently ICI are approved for the first-line therapy of cisplatin-unfit patients (Atezolizumab, Pembrolizumab) and second-line therapy in patients with metastasized urothelial cancer (Atezolizumab, Nivolumab, Pembrolizumab). For the therapy of metastasized RCC, Nivolumab is approved as a second-line therapy and in combination with the CTLA‑4 antibody Ipilimumab as a first-line therapy. What does the optimized radiological follow-up and therapy response assessment for ICI, which differ in their pathways from common chemotherapeutics and anti-angiogenetic drugs, look like? What strategies are needed to meet the upcoming challenges concerning interpretation of the acquired images? Asystematic literature search was carried out for urothelial and renal cell carcinoma. Immune-related response criteria have been introduced to better characterize the imaging changes occurring under ICI, as monitoring response to immunotherapy still relies on RECIST. To properly identify and predict response after treatment with ICI, additional studies with long-term follow-ups are needed. Because of the growing use of ICI, radiologists and urologist should be familiar with common imaging findings (such as pseudo progress) under immunotherapy to correctly interpret these findings in daily routine.

A comprehensive genome-wide profiling comparison between HBV and HCV infected hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is one of the most common cancers worldwide, especially in East Asia. Even with the progress in therapy, 5-year survival rates remain unsatisfied. Chronic infection with the hepatitis B virus (HBV) or hepatitis C virus (HCV) has been epidemiologically associated with HCC and is the major etiology in the East Asian population. The detailed mechanism, especially the changes of DNA methylation and gene expression between the two types of virus-related HCC, and their contributions to the HCC development, metastasis, and recurrence remain largely unknown.MethodsIn this integrated analysis, we characterized genome-scale profiles of HBV and HCV infected HCC by comparing their gene expression pattern, methylation profiles, and copy number variations from the publicly accessible data of The Cancer Genome Atlas Program (TCGA).ResultsThe HLA-A, STAT1, and OAS2 genes were highly enriched and up-regulated discovered in the HCV-infected HCC. Hypomethylation but not copy number variations might be the major factor for the up-regulation of these immune-related genes in HCV-infected HCC.ConclusionsThe results indicated the different epigenetic changes of HBV/HCV related hepatocarcinogenesis. The top up-regulated genes in HCV group were significantly clustered in the immune-related and defense response pathways. These findings will help us to understand the pathogenesis of HBV/HCV associated hepatocellular carcinoma.

1251P - Pathologic scoring of pre-treatment H&E biopsies predicts overall survival in patients with metastatic clear cell renal cell carcinoma receiving nivolumab monotherapy

BackgroundAnti-PD-1 therapy is effective and durable in a subset of patients with metastatic clear cell renal cell carcinoma (mCCRCC). Previous studies have suggested that PBRM1 mutations associate with response to anti-PD-1. Here, we assessed routine, pre-treatment hematoxylin and eosin-stained (H&E) slides for features of a pre-existing immune response to tumor and tested them for an association with overall survival (OS). MethodsWe studied prospectively-collected pre-treatment biopsies from 56 patients (n=15 treatment naïve; n=41 previously failed at least 1 prior anti-angiogenic agent) as part of the CheckMate 009 trial (NCT01358721). H&E-stained slides were scored by two pathologists blinded to patient outcome for features of immune-related pathologic response (irPR, Cottrell, Ann Oncol 2018; Stein, Ann Oncol 2019) and necrosis. Specifically, the co-localization of moderate-high tumor infiltrating lymphocytes, plasma cells, lymphoid aggregates, neovascularization, and proliferative fibrosis was scored and compared to OS. 23 patients also had genomic data available for study. ResultsH&E evidence of a pre-existing immune response to tumor (irPR score=1 or 2) associated with improved 5-year OS (median survival undefined at 5 years vs. 16.0 months, log-rank, p=0.006). Necrosis score alone did not associate with OS, however, a composite score (irPR minus necrosis) distinguished a population of patients with particularly poor OS following anti-PD-1 therapy (median survival 40.5 months vs. 12.3 months, log-rank, p=0.01). Prior systemic therapy did not affect irPR or necrosis scores (p>0.05, Fisher’s exact test). Patients positive for both an irPR score of 1 or 2 and PBRM1 mutation had significantly improved OS as compared to patients negative for both (median survival undefined vs. 7.9 months, log-rank p=0.002). ConclusionsPre-treatment H&E slides can be used to predict OS in patients with mCCRCC treated with anti-PD-1 using a routine surgical pathology workflow. Early evidence suggests that the combination of irPR scoring with genomic testing for PBRM1 may further stratify the predictive ability of these assessments beyond either individual approach alone. Clinical trial identificationNCT01358721. Legal entity responsible for the studyThe authors. FundingNIH T32 CA193145. DisclosureS. Signoretti: Advisory / Consultancy: AstraZeneca/MedImmune, Merck, AACR, NCI; Research grant / Funding (self): AstraZeneca, Exelixis, Bristol-Myers Squibb; Licensing / Royalties: Biogenex Laboratories. M. Sznol: Advisory / Consultancy: Bristol-Myers Squibb, Genentech/Roche, AstraZeneca-MedImmune, Novartis, Seattle Genetics, Nektar, Lilly, Biodesix, Modulate Therapeutics, Newlink Genetics, Molecular Partners, Innate Pharma, AbbVie, Immunocore, Genmab, Almac, Hinge, Anaeropharma, Array, G; Shareholder / Stockholder / Stock options: Amphivena, Intensity Therapeutics, Adaptive Biotechnologies, Nextcure, Actym, Torque . Y. Ishii: Shareholder / Stockholder / Stock options, Full / Part-time employment: Bristol-Myers Squibb. D.F. McDermott: Advisory / Consultancy: Bristol-Myers Squibb, Merck, Pfizer, Novartis, Eisai, Exelixis, Array BioPharma, Alkermes, Inc., Jounce Therapeutics, X4 Pharmaceuticals, Peloton Therapeutics, EMD Serono and Genentech BioOncology, Eli Lilly; Research grant / Funding (self): Bristol-Myers Squibb, Prometheus Laboratories, Merck, Genentech, Pfizer, Exelixis, Novartis, X4 Pharmaceuticals, Alkermes, Inc. and Peloton. T.K. Choueiri: Research grant / Funding (self), Research grant / Funding (institution): AstraZeneca, Bayer, BMS, Cerulean, Eisai, Foundation Medicine Inc., Exelixis, Ipsen, Tracon, Genentech, Roche, Roche Products Limited, GlaxoSmithKline, Merck, Novartis, Peloton, Pfizer, Prometheus Labs, Corvus, Calithera, Analysis Group, Takeda; Honoraria (self), Honoraria (institution): AstraZeneca, Alexion, Sanofi/Aventis, Bayer, BMS, Cerulean, Eisai, Foundation Medicine Inc., Exelixis, Genentech, Roche, GlaxoSmithKline, Merck, Novartis, Peloton, Pfizer, EMD Serono, Prometheus Labs, Corvus, Ipsen, Up-to-Date, NCCN, Analysis Group, NCCN,; Advisory / Consultancy: AstraZeneca, Alexion, Sanofi/Aventis, Bayer, BMS, Cerulean, Eisai, Foundation Medicine Inc., Exelixis, Genentech, Heron Therapeutics, Roche, GlaxoSmithKline, Merck, Novartis, Peloton, Pfizer, EMD Serono, Prometheus Labs, Corvus, Ipsen, Up-to-Date, NCCN, A. J.M. Taube: Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Merck; Advisory / Consultancy: Amgen. All other authors have declared no conflicts of interest.

1452P - Prognostic significance of elements of the adaptive immunity in the microenvironment of early-stage non-small cell lung cancer

BackgroundThe characterization of adaptive immunity in the tumor microenvironment of non small cell lung cancer (NSCLC) is considered of outmost importance for the stratification of patients for immunotherapeutic approaches. For this, simple, feasible, inexpensive, reproducible and pathology based methodologies are needed, such as the evaluation of routine H&E stained slides, an approach that has been recently used for the interpretation of the immune-related pathologic response in the neoadjuvant immunotherapy setting. MethodsWe aimed to determine the prognostic significance of intratumoral and peritumoral tertiary lymphoid structures (TLS), plasma cells (PCs) and necrosis in a series of 140 patients with early stage, surgically resectable NSCLC. The evaluation of TLS (3-tiered score), PCs (4-tiered score) and necrosis (absent, focal, diffuse) was performed in hematoxylin-eosin (H&E) sections from surgical specimens of pulmonary wedge resection, lobectomy or pneumonectomy. Epidemiological data have been retrieved for 76 patients so far. ResultsIn most of the tumors examined, presence of TLS and aggregates of PCs was noted (91% and 75%, respectively). The presence and density of TLS and PCs in the tumor microenvironment correlated with improved survival (p<0.001 and p=0.002 respectively, Kaplan-Meier). The presence of TLS also correlated positively with PC infiltrates (p<0.001, CC=0.644, Spearman). Importantly, all patients with diffuse large PCs aggregates (score 3) are alive for the follow-up period. On the contrary, the presence of diffuse necrosis proved to have an adverse effect on overall survival (p=0.004, Kaplan-Meier) and showed no significant correlation with the presence of TLS and PCs. ConclusionsThe presence of elements of the adaptive immunity such as TLS and plasma cells is closely linked to clinical outcome in NSCLC. As plasma cell differentiation in the tumor environment correlated with the presence of TLS, this effector humoral immunity cell type might represent a surrogate marker of an effective immune response in the tumor microenvironment driven by the formation of Tertiary Lymphoid Structures. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

LBA70 - Talimogene laherparepvec (T-VEC) in combination (combo) with ipilimumab (ipi) versus ipi alone for advanced melanoma: 3-year landmark analysis of a randomized, open-label, phase II trial

LBA70 - Talimogene laherparepvec (T-VEC) in combination (combo) with ipilimumab (ipi) versus ipi alone for advanced melanoma: 3-year landmark analysis of a randomized, open-label, phase II trial

1365P - Final results from phase II of combination with canerpaturev (formerly HF10), an oncolytic viral immunotherapy, and ipilimumab in unresectable or metastatic melanoma in second-or later line treatment

1365P - Final results from phase II of combination with canerpaturev (formerly HF10), an oncolytic viral immunotherapy, and ipilimumab in unresectable or metastatic melanoma in second-or later line treatment

1179PD - Natural dendritic cell vaccinations generate immune responses that correlate with clinical outcome in patients with chemo-naive castration-resistant prostate cancer

BackgroundClinical benefit of cellular immunotherapy has been shown in patients with castration-resistant prostate cancer (CRPC). We investigated the immunological response and clinical outcome of vaccination with blood-derived myeloid and plasmacytoid dendritic cells (mDCs and pDCs). MethodsIn this randomized phase IIa trial, 21 chemo-naive CRPC patients received maximally 9 vaccinations with mature mDCs, pDCs or a combination of mDCs plus pDCs. DCs were stimulated with protamine/mRNA and loaded with tumor-associated antigens NY-ESO-1, MAGE-C2 and MUC1. Primary endpoint was the immunological response after DC vaccination, which was monitored in peripheral blood and in T cell cultures of biopsies of post-treatment delayed-type hypersensitivity (DTH)-skin tests. Main secondary endpoints were safety, feasibility, radiological PFS (rPFS) and OS. Radiological responses were assessed by regular as well as ferumoxtran-10 enriched MRI and 68Ga-PSMA PET/CT scans according to RECIST 1.1, PCWG2 criteria and immune-related response criteria. ResultsBoth tetramer/dextramer-positive (dm+) and IFN-γ-producing (IFN-γ+) DTH-skin test-derived antigen specific T cells were present more frequently in patients with radiological non-progressive disease compared to progressive patients (5/13 (38%) vs. 0/8 (0%)). In dm+ and IFN-γ+ patients median rPFS was 18.8 months vs. 5.1 months in patients without IFN-γ+ antigen-specific T cells (p=0.02). The overall median rPFS was 9.5 months. All DC vaccines were well tolerated with grade 1-2 toxicity. Immunological outcomes and clinical correlates will be presented. ConclusionsImmunotherapy with primary DC subsets induced functional antigen-specific T cells. The presence of functional antigen-specific T cells correlated with longer rPFS. Clinical trial identificationNCT02692976. Legal entity responsible for the studyJolanda de Vries and Winald Gerritsen. FundingThis work was supported by Stichting Afweer Tegen Kanker, Dr. Paul A.J. Speth Stichting and H2020 EU grant PROCROP (grant No 635122). Carl G. Figdor received ERC Adv Grant PATHFINDER (269019) and the NWO Spinoza grant. I. Jolanda M. de Vries received NWO-Vici grant (918.14.655). DisclosureAll authors have declared no conflicts of interest.

P1.01-69 Blood Serum Amyloid A as Potential Predictor of Response to First-Line Pembrolizumab in Patients with Advanced Non-Small-Cell Lung Cancer

The selection of patients (pts) deriving clinical benefit from immune checkpoint agents represents the modern challenge for clinicians. Tumor-derived Serum Amyloid A (SAA) inhibits the immune response through the expansion of IL-10-secreting neutrophils in pts with melanoma. We investigated the predictive value of blood SAA monitoring in a cohort of Advanced Non-Small-Cell Lung Cancer (ANSCLC) pts receiving up-front Pembrolizumab (P). Pts with ANSCLC (PD-L1≥50%) receiving upfront P, were prospectively evaluated for blood SAA and radiological response at baseline and every 9 weeks during the treatment. The primary endpoint was response rate (RR) according Immune-related Response Evaluation Criteria in Solid Tumors (IrRECIST); the secondary endpoints were progression-free survival (PFS) and overall survival (OS). The most accurate SAA cut-off to predict response was established with a ROC-analysis. Forty-two patients were enrolled. Pts characteristics: male/female (71/29%), number of sites 1/2/3/≥ 4 (5/38/40/17%), ECOG PS 0/≥ 1 (38/62%); never or former/current smokers (12/78%); median age 70.5 (range 35-86) years. The overall RR was 38% (95%CI 25-53%). After a median follow-up of 13.5 months (m), baseline SAA ≤ the ROC-derived cut-off (29.9 mg/L, AUC 0.74, 95% CI 0.59-0.87, p=0.002; 14 [33%] pts) was significantly associated with a higher RR (53.6vs 7.1%, OR 15, 95% CI 1.72-130.7, p<0.01), longer PFS (17.4 vs 2.1 m, HR 0.18, 95%CI 0.06-0.51, p<0.0001) and OS (not reached [NR]vs7.2 m, HR 0.08, 95%CI 0.02-0.39, p<0.0001) compared with SAA >29.9 mg/L. Multivariate analysis confirmed pre-treatment low SAA as independent predictor of longer PFS (p=0.029) and OS (p=0.018). Considering SAA at baseline and the dynamic monitoring (pts=40), the median PFS was 17.4 m (95% CI 10.7-14.7) when SAA remained low (n=14) compared with 2.1 m (95%CI 1.3-5.6) when SAA remained high (n=12) (p<0.0001).The SAA monitoring was also significantly associated with OS (p=0.0002), with a median OS of 7.2 m (95% CI 5.6-13.4) in pts maintaining high SAA versus NR median at 18-m for pts with SAA remained low or changed. No deaths occurred in the permanently low-SAA group at the current data-lock. Baseline low SAA predicts good outcomes of 1stline P and the SAA monitoring throught simple blood test could help to easily identify patients who derived the greatest benefit from immunotherapy. The strong relationship with RR and the known immunosuppressive activity support a potential predictive value of this serum marker. A multi-institutional validation set is currently ongoing to confirm the role of SAA in this setting.

Phase II clinical trial of pembrolizumab efficacy and safety in advanced adrenocortical carcinoma

BackgroundAdrenocortical carcinoma (ACC) is a rare malignancy without good treatment options. There are limited data about the use of immunotherapy in ACC. We investigated the efficacy and safety of pembrolizumab in patients with metastatic ACC.MethodsThis is a pre-specified cohort of a single-center, investigator-initiated, phase II clinical trial using pembrolizumab monotherapy in patients with rare malignancies. Patients must have had prior treatment fail in the past 6 months before study enrollment. Patients were enrolled from August 2016 to October 2018. Follow-up data were updated as of March 26, 2019.Patients received 200 mg pembrolizumab intravenously every 3 weeks without concomitant oncologic therapy. The primary endpoint was non-progression rate (NPR) at 27 weeks. Other endpoints included adverse events, tumor responses measured independently by objective radiologic criteria, and select immunological markers.ResultsSixteen patients with ACC (including eight women [50%]) were included in this cohort. Ten patients (63%) had evidence of hormonal overproduction (seven had cortisol-producing ACC). Non-progression rate at 27 weeks was evaluable in 14 patients, one patient was lost to follow-up, and one patient left the study because of an adverse event. Five of 14 patients were alive and progression-free at 27 weeks (non-progression rate at 27 weeks was 36, 95% confidence interval 13–65%). Of the 14 patients evaluable for imaging response by immune-related Response Evaluation Criteria in Solid Tumors, two had a partial response (including one with cortisol-producing ACC), seven had stable disease (including three with cortisol-producing ACC), and five had progressive disease, representing an objective response rate of 14% (95% confidence interval 2–43%). Of those who had stable disease, six had disease stabilization that lasted ≥4 months. Severe treatment-related adverse events (≥grade 3) were seen in 2 of 16 patients (13%) and resulted in one patient discontinuing study participation. All studied tumor specimens (14/14) were negative for programmed cell death ligand-1 expression. Thirteen of 14 tumor specimens (93%) were microsatellite-stable. Eight of 14 patients (57%) had a high tumor-infiltrating lymphocyte score on immunohistochemistry staining.ConclusionsSingle-agent pembrolizumab has modest efficacy as a salvage therapy in ACC regardless of the tumor’s hormonal function, microsatellite instability status, or programmed cell death ligand-1 status. Treatment was well tolerated in most study participants, with a low rate of severe adverse events.Trial registrationClinicalTrials.gov identifier: NCT02721732, Registered March 29, 2016.

Tumour flare reaction in cancer treatments: a comprehensive literature review.

In the past decade, tumour flare reaction (TFR) was considered as a new side effect associated with immunomodulatory agents (IMiDs) and as a condition of chronic lymphocytic leukaemia (CLL). However, this phenomenon is also observed with immune checkpoint inhibitors in solid tumours. It is still poorly understood and its incidence is underestimated. TFR has been associated with morbidity, therefore, early recognition and management of patients with TFR is critical. An exhaustive literature research between 1985 and 2016 was performed using PubMed; American Society of Clinical Oncology and American Society of Hematology abstracts reporting TFR or pseudoprogression were identified. The incidence of TFR in CLL ranged from 28 to 58%. Tumour response in patients treated beyond progression was reported in 9.7% with ipilimumab, 10% with nivolumab, 6.7 and 12% with pembrolizumab, and in renal cell carcinoma 69% with nivolumab. Rare life-threatening or fatal cases were reported; symptoms were usually mild. Studies showed that treating patients beyond progression yielded tumour responses, considering TFR as predictive of response. Treatment with immunomodulatory agents is associated with TFR, often misinterpreted as progression. Therefore, the identification of appropriate clinical benefit criteria and the use of immune-related response criteria in prospective trials for a better understanding are compulsory.

Immune-related genes response to stimulation of miR-155 overexpression in CIK (ctenopharyngodon idella kidney) cells and zebrafish

MiR-155 regulates the development of germinal-center and the generation of immunoglobulin class-switched plasma cells. However, whether miR-155 is involved in immune response in fish is still unclear. Here, CIK cells transfected with miR-155 overexpressed plasmid inhibited mRNA expression of mIg and Rag2 (P < 0.05). Interestingly, mIg was predicted as a potential target gene of miR-155 by RNAhybrid, with a putative binding site in its CDS. Further, mIg luciferase reporter vectors with successive deletions of mIg cDNA sequence were constructed and dual luciferase reporter assay showed that vectors containing the sequence from 318 to 347 in CDS exhibited lower relative luciferase activity than others without predicted binding region (P < 0.05), which indicated mIg is the target gene of miR-155 and reveal bona fide targeted binding site of mIg for miR-155 in fish. In vivo, the zebrafish were respectively injected with miR-155 overexpressed and empty vector, and showed that miR-155 efficiently expressed in zebrafish (P < 0.01), which consistently decreased mRNA level of immune-related genes, including mIg (P < 0.01), sIg (P < 0.05), AID (P < 0.01), PU.1 (P < 0.05) and Rag2 (P < 0.05) at d 3 and d 6 post injection, comparing to control. Collectively, this work indicates that overexpression of miR-155 suppresses the mRNA level of immune-related genes in CIK cells and zebrafish, and mIg is a novel target gene of miR-155 in fish. These findings provide an insight into the miR-155 modulating adaptive immunity in grass carp and zebrafish.