Real-world evidence of Pressure-Enabled Drug Delivery for trans-arterial chemoembolization and radioembolization among patients with hepatocellular carcinoma and liver metastases

OBJECTIVES

Pressure-Enabled Drug Delivery (PEDD), a method using pressure to advance catheter-delivered drug distribution, can improve treatment for hepatocellular carcinoma (HCC) and liver metastases, but real-world evidence is limited. We compared baseline patient characteristics, clinical complexity, and post-procedure healthcare resource utilization (HRUs) and clinical complications for PEDD and non-PEDD procedures.

METHODS

This study used a retrospective, longitudinal, cohort design of claims data from Clarivate's Real World Data Repository, which includes 98% of US payers with over 300 million unique patients from all US states. We identified patients with a trans-arterial chemoembolization (TACE) or trans-arterial radioembolization (TARE) from 1 January 2019 to 31 December 2022. Subsamples grouped patients with HCC receiving a TARE procedure at their first embolization and patients with metastatic colorectal cancer (CRC) that received a TARE procedure. We reported descriptive comparisons of our full sample of patients with HCC and liver metastases receiving PEDD versus non-PEDD procedures. We then conducted a matching-adjusted comparison of HRUs and clinical complications for PEDD and non-PEDD patients among our subsamples (HCC receiving a TARE procedure at their first embolization and patients with metastatic CRC that received a TARE procedure). Matching was based on baseline demographic and clinical characteristics using coarsened exact matching and propensity-score matching. HRUs included inpatient, outpatient, and emergency department visits. Clinical complications included ascites, cholecystitis, fatigue, gastric ulcer, gastritis, jaundice, LFT increase, lymphopenia, portal hypertension, and post-embolization syndrome.

RESULTS

PEDD procedures were used on patients with worse baseline disease burdens: baseline Charlson comorbidity index (mean of 6.5 vs. 5.8), any prior clinical complication related to underlying disease (33.7 vs. 31.0%), and prior systemic therapy (22.1% vs. 16.2%). PEDD patients had a greater number of procedural codes indicative of technical complexity for TACE (PEDD mean = 226.3; non-PEDD mean = 134.5; p value <.01) and TARE (PEDD mean = 205.56; non-PEDD mean = 94.8; p value <0.01). Matching-adjusted analyses of patients with HCC and CRC demonstrated comparable HRU and clinical complications for PEDD and non-PEDD procedures post-index.

CONCLUSION

Despite higher baseline disease burden and complexity, post-procedure HRU and clinical complications for PEDD patients were similar to non-PEDD patients. The complex baseline clinical profile may reflect selection of challenging cases for PEDD use. Future studies should validate the benefits observed with PEDD embolization in larger samples with greater statistical power.

Pressure-Enabled Drug Delivery (PEDD) of a class C TLR9 agonist in combination with checkpoint inhibitor therapy in a murine pancreatic cancer model

BACKGROUND

Systemic immunotherapy has had limited clinical benefit in pancreatic ductal adenocarcinoma. This is thought to be due to its desmoplastic immunosuppressive tumor microenvironment in addition to high intratumoral pressures that limit drug delivery. Recent preclinical cancer models and early-phase clinical trials have demonstrated the potential of toll-like receptor 9 agonists, including the synthetic CpG oligonucleotide SD-101, to stimulate a wide range of immune cells and eliminate suppressive myeloid cells. We hypothesized that Pressure-Enabled Drug Delivery via Pancreatic Retrograde Venous Infusion of toll-like receptor 9 agonist would improve responsiveness to systemic anti-programmed death receptor-1 checkpoint inhibitor therapy in a murine orthotopic pancreatic ductal adenocarcinoma model.

METHODS

Murine pancreatic ductal adenocarcinoma (KPC4580P) tumors were implanted into the pancreatic tails of C57BL/6J mice and treated 8 days after implantation. Mice were assigned to one of the following treatment groups: Pancreatic Retrograde Venous Infusion delivery of saline, Pancreatic Retrograde Venous Infusion delivery of toll-like receptor 9 agonist, systemic anti-programmed death receptor-1, systemic toll-like receptor 9 agonist, or the combination of Pancreatic Retrograde Venous Infusion delivery of toll-like receptor 9 agonist and systemic anti-programmed death receptor-1 (Combo). Fluorescently labeled toll-like receptor 9 agonist (radiant efficiency) was used to measure uptake of the drug on day 1. Changes in tumor burden were evaluated by necropsy at 2 different time points, 7 and 10 days after toll-like receptor 9 agonist treatment. Blood and tumors were collected at necropsy 10 days after toll-like receptor 9 agonist treatment for flow cytometric analysis of tumor-infiltrating leukocytes and plasma cytokines.

RESULTS

All mice analyzed survived to necropsy. Site of tumor fluorescence measurements revealed 3-fold higher intensity fluorescence in Pancreatic Retrograde Venous Infusion delivery of toll-like receptor 9 agonist compared to systemic toll-like receptor 9 agonist mice. Tumor weights were significantly lower in the Combo group compared to Pancreatic Retrograde Venous Infusion delivery of saline. Flow cytometry of the Combo group demonstrated significantly increased overall T-cell number, specifically CD4+ T-cells, and a trend toward increased CD8+ T-cells. Cytokine analysis showed significantly decreased IL-6 and CXCL1.

CONCLUSION

Pressure-Enabled Drug Delivery of toll-like receptor 9 agonist by Pancreatic Retrograde Venous Infusion with systemic anti-programmed death receptor-1 demonstrated improved pancreatic ductal adenocarcinoma tumor control in a murine pancreatic ductal adenocarcinoma model. These results support study of this combination therapy in pancreatic ductal adenocarcinoma patients and expansion of ongoing Pressure-Enabled Drug Delivery clinical trials.

Abstract 5881: PERIO-01: Initial safety experience and immunologic effects of a Class C TLR9 agonist using pressure- enabled drug delivery in a phase 1 trial of hepatic arterial infusion of SD-101 +/- checkpoint inhibition in metastatic uveal melanoma

Immune checkpoint inhibitors (ICI) have demonstrated limited success in patients with metastatic uveal melanoma (MUM) with liver involvement due to an immunosuppressive tumor microenvironment (TME) driven in part by myeloid-derived suppressor cells (MDSCs). Toll-like receptor-9 agonists (TLR-9A) have improved ICI response rates in cutaneous melanoma, but delivery challenges have limited their application for MUM. Hepatic arterial infusion (HAI) of TLR-9A using a pressure-enabled drug deliveryTM (PEDDTM) device has the potential to enhance responsiveness to ICI by optimizing delivery to intrahepatic tumors and reprogramming the TME, including elimination of MDSCs.PERIO-01 is an open-label first-in-human Phase 1 trial of SD-101 given by HAI using a PEDDTM in MUM (NCT04935229). The study consists of dose-escalation cohorts of single agent SD-101 alone and with ICI. SD-101 is delivered over 2 cycles, with 3 weekly doses per cycle. Research blood, tumor and normal liver biopsies are collected serially for correlative studies. At data cutoff, a total of 20 patients were enrolled, with 13 in the single agent dose escalation cohort (2, 4, and 8 mg) and 7 patients with SD-101 (2 mg) + nivolumab. The median age was 65.5 years with an equal gender distribution. Only 2 patients were treatment-naïve and the median number of liver metastases was 5.1. The average number of SD-101 infusions was 5.2. One patient in the combination cohort experienced a serious adverse event related to treatment - asymptomatic Grade 3 increase in liver enzymes. PEDDTM resulted in high drug levels in the liver (up to 2,340 ng/ml at 8mg) with only transient exposure in the periphery (&lt;4 hours) with one Grade 2 cytokine related syndrome adverse event. Dose-dependent increases in canonical TLR9-associated cytokines (IL-18, IFNγ, IP-10, and soluble CD25) was observed across the 2mg, 4mg, and 8mg single-agent dose levels. Concordant with predicted mechanism of action, PEDDTM HAI administered SD-101 resulted in decreases in liver monocytic MDSCs in 4 of 4 patients with available multiplex immunofluorescence data. NanoString analysis from three patients revealed increases in ISG15, IL-9, IFNα, and IL-2 transcripts and decreases in ARG1 and IDO transcripts, with increased scores for macrophages, activated CD8 T cells, Th1 cells, and Th1 activation. For patients who received 2mg SD-101 + ICI with available liquid biopsy data, 4 of 7 demonstrated decreases in circulating tumor cells and 3 of 5 showing ctDNA decreases after the first cycle. In this first-in-human experience, HAI of SD-101 via PEDDTM was well tolerated and associated with encouraging immunologic activity. Evidence of biologic activity with 2 mg of SD-101 with nivolumab is encouraging and patients are currently enrolling at higher SD-101 dose levels + ICI.

Citation Format: Sapna P. Patel, Cara Haymaker, Rahul A. Sheth, Joshua D. Kuban, Joshua Weintraub, Eric Wehrenberg-Klee, Paula Novelli, Carin Gonsalves, Robert Adamo, Virgina Honaker, Laura Timciuc, Tarin Hennegan, Juan C. Amador Molina, Dzifa Duose, Edwin R. Parras Cuenta, Anthony Lucci, Salyna Meas, Vanessa Sarli, Victor G. Prieto, Jason LaPorte, Ann-Marie Hulstine, Ashley Moody, Bryan Cox, David Geller, Diwakar Davar, Kamaneh Montazeri, Marlana Orloff, Steven C. Katz, Richard Carvajal. PERIO-01: Initial safety experience and immunologic effects of a Class C TLR9 agonist using pressure- enabled drug delivery in a phase 1 trial of hepatic arterial infusion of SD-101 +/- checkpoint inhibition in metastatic uveal melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5881.

Blockade of interleukin 10 potentiates antitumour immune function in human colorectal cancer liver metastases

OBJECTIVE

Programmed cell death protein 1 (PD-1) checkpoint inhibition and adoptive cellular therapy have had limited success in patients with microsatellite stable colorectal cancer liver metastases (CRLM). We sought to evaluate the effect of interleukin 10 (IL-10) blockade on endogenous T cell and chimeric antigen receptor T (CAR-T) cell antitumour function in CRLM slice cultures.

DESIGN

We created organotypic slice cultures from human CRLM (n=38 patients' tumours) and tested the antitumour effects of a neutralising antibody against IL-10 (αIL-10) both alone as treatment and in combination with exogenously administered carcinoembryonic antigen (CEA)-specific CAR-T cells. We evaluated slice cultures with single and multiplex immunohistochemistry, in situ hybridisation, single-cell RNA sequencing, reverse-phase protein arrays and time-lapse fluorescent microscopy.

RESULTS

αIL-10 generated a 1.8-fold increase in T cell-mediated carcinoma cell death in human CRLM slice cultures. αIL-10 significantly increased proportions of CD8⁺ T cells without exhaustion transcription changes, and increased human leukocyte antigen - DR isotype (HLA-DR) expression of macrophages. The antitumour effects of αIL-10 were reversed by major histocompatibility complex class I or II (MHC-I or MHC-II) blockade, confirming the essential role of antigen presenting cells. Interrupting IL-10 signalling also rescued murine CAR-T cell proliferation and cytotoxicity from myeloid cell-mediated immunosuppression. In human CRLM slices, αIL-10 increased CEA-specific CAR-T cell activation and CAR-T cell-mediated cytotoxicity, with nearly 70% carcinoma cell apoptosis across multiple human tumours. Pretreatment with an IL-10 receptor blocking antibody also potentiated CAR-T function.

CONCLUSION

Neutralising the effects of IL-10 in human CRLM has therapeutic potential as a stand-alone treatment and to augment the function of adoptively transferred CAR-T cells.

Regional infusion of a class C TLR9 agonist enhances liver tumor microenvironment reprogramming and MDSC reduction to improve responsiveness to systemic checkpoint inhibition

Myeloid-derived suppressor cells (MDSCs) expand in response to malignancy and suppress responsiveness to immunotherapy, including checkpoint inhibitors (CPIs). Within the liver, MDSCs have unique immunosuppressive features. While TLR9 agonists have shown promising activities in enhancing CPI responsiveness in superficial tumors amenable to direct needle injection, clinical success for liver tumors with TLR9 agonists has been limited by delivery challenges. Here, we report that regional intravascular infusion of ODN2395 into mice with liver metastasis (LM) partially eliminated liver MDSCs and reprogrammed residual MDSC. TLR9 agonist regional infusion also induced an increase in the M1/M2 macrophage ratio. Enhanced TLR9 signaling was demonstrated by an increased activation of in NFκB (pP65) and production of IL6 compared with systemic infusion. Further, PBMC-derived human MDSCs express TLR9, and treatment with class C TLR9 agonists (ODN2395 and SD101) reduced the expansion of MDSC population. TLR9 stimulation induced MDSC apoptosis and increased the M1/M2 macrophage ratio. Regional TLR9 agonist infusion along with systemic anti-PD-1 therapy improved control of LM. With effective delivery, TLR9 agonists have the potential to favorably reprogram the liver TME through reduction of MDSCs and favorable macrophage polarization, which may improve responsiveness to systemic CPI therapy.

Regional Delivery of CAR-T Effectively Controls Tumor Growth in Colorectal Liver Metastasis Model

BACKGROUND

Effective treatment of solid tumors requires multi-modality approaches. In many patients with stage IV liver disease, current treatments are not curative. Chimeric antigen receptor T cells (CAR-T) are an intriguing option following success in hematological malignancies, but this has not been translated to solid tumors. Limitations include sub-optimal delivery and elevated interstitial fluid pressures. We developed a murine model to test the impact of high-pressure regional delivery (HPRD) on trafficking to liver metastases (LM) and tumor response.

MATERIALS AND METHODS

CAR-T were generated from CD45.1 mice and adoptively transferred into LM-bearing CD45.2 mice via regional or systemic delivery (RD, SD). Trafficking, tumor growth, and toxicity were evaluated with flow cytometry, tumor bioluminescence (TB, photons/sec log₂-foldover baseline), and liver function tests (LFTs).

RESULTS

RD of CAR-T was more effective at controlling tumor growth versus SD from post-treatment days (PTD) 2-7 (P = 0.002). HPRD resulted in increased CAR-T penetration versus low-pressure RD (LPRD, P = 0.004), suppression of tumor proliferation (P = 0.03), and trended toward improved long-term control at PTD17 (TB=3.7 versus 6.1, P = 0.47). No LFT increase was noted utilizing HPRD versus LPRD (AST/ALT P = 0.65/0.84) while improved LFTs in RD versus SD groups suggested better tumor control (HPRD AST/ALT P = 0.04/0.04, LPRD AST/ALT P = 0.02/0.02).

CONCLUSIONS

Cellular immunotherapy is an emerging option for solid tumors. Our model suggests RD and HPRD improved CAR-T penetration into solid tumors with improved short-term tumor control. Barriers associated with SD can be overcome using RD techniques to maximize therapeutic delivery and HPRD may further augment efficacy without increased toxicity.

Abstract 1793: Regional administration of class C CpG Oligodeoxynucleotides results in superior intrahepatic TLR9 activation and immunomodulation compared to systemic infusion

CpG oligodeoxynucleotides (ODNs) are TLR9 agonists (TLR9As) that stimulate pDC and B cells. Yet, multiple other cell types in the liver express TLR9. The effect of TLR9A in reshaping the tumor microenvironment (TME), particularly in the myeloid-derived suppressor cells (MDSC) compartment, is yet to be determined. Clinical success of TLR9As has been limited by toxicity when given systemically and delivery limitations when administered by direct needle injection. Here, we hypothesized that regional intra-vascular infusion of TRL9As would reprogram the liver MDSC compartment to enable immune control of liver metastases (LM). In this study, we evaluated the effect of class C ODN-2395 as TLR9A in inhibiting LM progression and its impact on the liver MDSC population. C57/BL6 mice were challenged with 2.5e6 MC38-CEA-Luc cells via intra-splenic route. After a week, mice were treated with 1, 3, 10 or 30 µg ODN2395 via PV or IV (30 µg). Bioluminescence was measured at 24 and 48 hrs post-ODN administration. CD45+ cells were isolated, and FACS analysis was performed to quantify MDSCs, monocytic MDSCs (M-MDSC), and M1-macrophage subsets, along with downstream signaling. We found that 30 µg ODN2395 delivered via PV compared to IV reduced tumor burden at 24 hrs and persisted up to 48 hrs. Also, 30 µg ODN2395 infused via PV was optimal in controlling MDSC, M-MDSC cells and polarized CD11b+F4/80+ monocytic cells towards pro-inflammatory/anti-tumorigenic M1 macrophage. Using an NFκB-dependent soluble alkaline phosphatase assay (SEAP), we determined that ODN2395 dose-dependently enhanced NFκB transcription factor activity (p&lt;0.001). Western Blot data of tumor lysates show that ODN delivery by PV increased NFκB (pP65) activity and production of IL-6, significantly relative to IV. Overall, our data suggest that the regional delivery of a TLR9A has the potential to provide superior modulation of the TME within the liver.

Table:Readout30µg IV30µg PVP valuenBioluminescence-24 h (photon/s)4e71e7&lt;0.0113Bioluminescence-48h (photon/s)7e72e7&lt;0.0513FACSCD11b+Gr1+ cells/CD45+ NPC (MDSC)29.70 %20.75%&lt;0.0113CD11b+LY6C+ (M-MDSC)60.03%38.98%&lt;0.0113CD11b+F4/80+CD38+EGR2-(M1 macrophage)34.82%58.20%&lt;0.0113Western BlottingpNFκB/NFκB (pP65s276/pP65): Fold change0.862.028&lt;0.016IL6/GAPDH Fold change12.387&lt;0.056

Citation Format: Chandra Ghosh, Kara Heatherton, Kyle O'Connell, Jason Laporte, Prajna Guha, David Jaroch, Bryan Cox, Steven C. Katz. Regional administration of class C CpG Oligodeoxynucleotides results in superior intrahepatic TLR9 activation and immunomodulation compared to systemic infusion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1793.

Activating chimeric receptor on IL-15 armored NK cells to improve in vitro and in vivo tumor response within the liver following regional delivery

e14517

Background: Colorectal cancer liver metastases (CRCLM) are a major source of morbidity and mortality. Historically, curative therapy has been limited to surgical resection, but only a small fraction of patients are eligible. Cellular immunotherapy has shown promise in hematologic cancers, but challenges to solid tumor therapy remain, including lymphocyte trafficking, elevated interstitial fluid pressures, and immunosuppression. Regional intravascular infusion is a non-surgical, minimally invasive procedure commonly used in liver cancer to deliver therapeutics, which can be augmented by Pressure Enabled Drug Delivery (PEDD). We hypothesized that utilizing established regional delivery strategies to administer natural killer (NK) cells engineered to express a natural killer group 2, member D (NKG2D) activating chimeric receptor and membrane bound IL-15 (CAR NKG2D cells) could increase anti-tumor activity against liver cancer. Methods: In vitro cytotoxicity of CAR NKG2D NK cells was determined in co-culture systems. CRCLM-bearing NSG mice were treated with either CAR NKG2D, non-transduced NK cells (NT-NK), or vehicle via portal vein (PV) for regional PEDD or tail vein (TV) for systemic delivery (SD). Tumor burden was measured via tumor bioluminescence. Mann-Whitney tests were performed for statistical comparisons. Correlation of NKG2D ligand expression in tissue and serum was measured by CODEX and Luminex. Results: Multiple NKG2D ligands are highly expressed in hepatocellular and colorectal carcinoma cell lines (HCC and CRC respectively). As such, these cells lines are highly susceptible to NKG2D-mediated cytotoxicity. CAR NKG2D NK cells were 3- to 4-fold more potent in vitro than NT-NK cells against multiple HCC and CRC cell lines, including those bearing Ras pathway mutations. Using a mouse model of locoregional delivery under high pressure (10 mL/minute), we show that significant tumor reduction (p < 0.05) is only achieved when CAR NKG2D NK cells, but not vehicle or NT-NK cells, were delivered via PV and not via TV. Recovery of CAR NKG2D NK cells in hepatic tissues was on average 2-fold higher after administration via PV than that observed after TV delivery (p = 0.0001). PV delivery of NT-NK cells did not result in appreciable liver engraftment or tumor growth inhibition. Conclusions: CAR NKG2D NK cells demonstrate enhanced in vitro and in vivo cytotoxicity against CRC and HCC cell lines. Significant tumor control using regional delivery in initial studies support continued clinical development. NKX101 is an investigational agent comprised of CAR NKG2D NK cells being evaluated in a phase 1 clinical study for treatment of relapsed/refractory acute myeloid leukemia or higher risk myelodysplastic syndrome. Studies are ongoing to understand NKX101 kinetics, role of delivery pressure, and activity in combination in preclinical models of CRCLM.

Tocilizumab for severe COVID-19 related illness - A community academic medical center experience

The SARS-CoV-2 virus responsible for the COVID-19 pandemic can result in severe or fatal disease in a subset of infected patients. While the pathogenesis of severe COVID-19 disease has yet to be fully elucidated, an overexuberant and harmful immune response to the SARS-CoV-2 virus may be a pivotal aspect of critical illness in this patient population. The inflammatory cytokine, IL-6, has been found to be consistently elevated in severely ill COVID-19 patients, prompting speculation that IL-6 is an important driver of the pathologic process. The inappropriately elevated levels of inflammatory cytokines in COVID-19 patients is similar to cytokine release syndrome (CRS) observed in cell therapy patients. We sought to describe outcomes in a series of severely ill patients with COVID-19 CRS following treatment with anti-IL-6/IL-6-Receptor (anti-IL-6/IL-6-R) therapy, including tocilizumab or siltuximab. At our academic community medical center, we formed a multi-disciplinary committee for selecting severely ill COVID-19 patients for therapy with anti-IL-6 or IL-6-R agents. Key selection criteria included evidence of hyperinflammation, most notably elevated levels of C-reactive protein (CRP) and ferritin, and an increasing oxygen requirement. By the data cutoff point, we treated 31 patients with anti-IL-6/IL-6-R agents including 12 who had already been intubated. Overall, 27 (87%) patients are alive and 24 (77%) have been discharged from the hospital. Clinical responses to anti-IL-6/IL-6-R therapy were accompanied by significant decreases in temperature, oxygen requirement, CRP, IL-6, and IL-10 levels. Based on these data, we believe anti-IL-6/IL-6-R therapy can be effective in managing early CRS related to COVID-19 disease. Further study of anti-IL-6/IL-6-R therapy alone and in combination with other classes of therapeutics is warranted and trials are underway.

Pressure-Enabled Drug Delivery Approach in the Pancreas with Retrograde Venous Infusion of Lipiodol with Ex Vivo Analysis

Purpose

To determine the safety and feasibility of pancreatic retrograde venous infusion (PRVI) utilizing a microvalvular infusion system (MVI) to deliver ethiodized oil (lipiodol) by means of the Pressure-Enabled Drug Delivery (PEDD) approach.

Methods

Utilizing transhepatic access, mapping of the pancreatic body and head venous anatomy was performed in 10 swine. PEDD was performed by cannulation of veins in the head (n = 4) and body (n = 10) of the pancreas with a MVI (Surefire® Infusion System (SIS), Surefire Medical, Inc (DBA TriSalus™ Life Sciences)) followed by infusion with lipiodol. Sets of animals were killed either immediately (n = 8) or at 4 days post-PRVI (n = 2). All pancreata were harvested and studied with micro-CT and histology. We also performed three-dimensional volumetric/multiplanar imaging to assess the vascular distribution of lipiodol within the glands.

Results

A total of 14 pancreatic veins were successfully infused with an average of 1.7 (0.5–2.0) mL of lipiodol. No notable change in serum chemistries was seen at 4 days. The signal-to-noise ratio (SNR) of lipiodol deposition was statistically increased both within the organ in target relative to non-target pancreatic tissue and compared to extra pancreatic tissue (p < 0.05). Histological evaluation demonstrated no evidence of pancreatic edema or ischemia.

Conclusions

PEDD using the RVI approach for targeted pancreatic infusions is technically feasible and did not result in organ damage in this pilot animal study.

HITM-SURE: Hepatic immunotherapy for metastases phase Ib anti-CEA CAR-T study utilizing pressure enabled drug delivery

In recent years, cell therapy technologies have resulted in impressive results in hematologic malignancies. Treatment of solid tumors with chimeric antigen receptor T-cells (CAR-T) has been less successful. Solid tumors present challenges not encountered with hematologic cancers, including high intra-tumoral pressure and ineffective CAR-T trafficking to the site of disease. Novel delivery methods may enable CAR-T therapies for solid tumor malignancies. A patient with liver metastases secondary to pancreatic adenocarcinoma received CAR-T targeting carcinoembryonic antigen (CEA). Previously we reported that Pressure-Enabled Drug Delivery (PEDD) enhanced CAR-T delivery to liver metastases 5.2-fold. Three doses of anti-CEA CAR-T were regionally delivered via hepatic artery infusion (HAI) using PEDD technology to optimize the therapeutic index. Interleukin-2 was systemically delivered by continuous intravenous infusion to support CAR-T in vivo. HAI of anti-CEA CAR-T was not associated with any serious adverse events (SAEs) above grade 3 and there were no on-target/off-tumor SAEs. Following CAR-T treatment, positron emission tomography-CT demonstrated a complete metabolic response within the liver, which was durable and sustained for 13 months. The response was accompanied by normalization of serum tumor markers and an abundance of CAR+ cells found within post-treatment tumor specimens. The findings from this report exhibit biologic activity and safety of regionally infused CAR-T for an indication with limited immune-oncology success to date. Further studies will determine how HAI of CAR-T may be included in multidisciplinary treatment plans for patients with liver metastases. ClinicalTrials.gov number, NCT02850536.

Pressure-enabled delivery of gemcitabine in an orthotopic pancreatic cancer mouse model

BACKGROUND

We describe the use of pancreatic retrograde venous infusion in an orthotopic murine model of pancreatic ductal adenocarcinoma and hypothesize that pancreatic retrograde venous infusion delivery of gemcitabine will increase concentrations of gemcitabine in the tumor and the subsequent tumor response to treatment.

METHODS

Murine pancreatic ductal adenocarcinoma (KPC4580P) was transplanted onto the pancreatic tail of C57BL/6J mice. Groups (n = 15) of mice were assigned to sham laparotomy and 100 mg/kg intraperitoneal infusion of gemcitabine (systemic gemcitabine), pancreatic venous isolation with pancreatic retrograde venous infusion of 100 mg/kg gemcitabine, or pancreatic retrograde venous infusion with saline infusion. Tumor pressures were recorded during pancreatic retrograde venous infusion. Mice were killed at 1 hour or 7 days after infusion.

RESULTS

Baseline tumor pressures were 45 ± 8 mm Hg, and pancreatic retrograde venous infusion increased tumor pressures by 29 ± 6 mm Hg (P < .01). Pancreatic retrograde venous infusion gemcitabine mice had greater tumor gemcitabine concentrations compared with systemic gemcitabine (127 vs 19 ng/mg; P < .01) and lesser tumor volumes compared with both systemic gem and pancreatic retrograde venous infusion with saline (274 vs 857 vs 629 mm³; P < .01).

CONCLUSION

Pancreatic retrograde venous infusion increased tumor pressures greater than baseline, improved gemcitabine delivery, and increased the treatment response. These findings suggest that pressurized, regional delivery overcomes the increased pressure barrier in pancreatic ductal adenocarcinoma. Additional preclinical studies with cytotoxic and immunotherapeutic agents and clinical trials using pressure-enabled drug delivery with pancreatic retrograde venous infusion devices are underway.

Effect of activating chimeric receptor on IL-15 armored NK cell on providing in vitro and in vivo antigen specific tumor response

e15016

Background: Colorectal cancer liver metastases (CRCLM) are a major source of morbidity and mortality. Historically, curative therapy has been limited to surgical resection, but only a small fraction of patients are eligible. Cellular immunotherapy has shown promise in hematologic cancers, but challenges related to solid tumor therapy remain with optimal cell trafficking, elevated interstitial fluid pressures (IFP), and immunosuppression. We hypothesized that engineered natural killer (NK) cells expressing a natural killer group 2, member D (NKG2D) activating chimeric receptor (ACR) and membrane bound IL-15 (NKX101) would increase anti-tumor activity in vitro and in vivo utilizing our established regional delivery strategies. Methods: In vitro cytotoxicity and cytokine release of NKX101 cells or non-transduced NK cells (NT-NK) derived from the same donor were determined by co-culture systems with HCT116 cells that endogenously express NKG2D ligands. CRCLM-bearing NSG™ mice were treated with NKX101, NT-NK, or vehicle (CTRL) via portal vein (PV) for regional delivery (RD) or tail vein (TV) for systemic delivery (SD). Tumor burden (TB) was measured via tumor bioluminescence (TBL) and histopathology (HP). Flow cytometry (FC) determined the quantity of cells delivered. Student’s t-test and Mann-Whitney tests were performed for statistical comparisons. Results: NKX101 transduction efficiencies ranged between 63.5 – 75.6% across 3 separate healthy donors. EC50 values derived from a 4-hour cytotoxicity assay for NKX101 vs. NT-NK were 3-4 fold lower with the greatest difference observed at the 1:1 effector-to-target (E:T) ratio (mean percent cytotoxicity: 72% vs. 20%, p = 0.001). In vitro cytokine assessment revealed 2.0-2.6 fold increases in IFN-γ, GM-CSF, and TNF-α levels compared to NT-NK cells (p < 0.0001 across all groups). In vivo, FC showed 2.89-fold increase in cell delivery using RD vs. SD on PTD1 (n = 3, p = 0.006). TBL was improved with 5 x 106 cells via PV vs. TV (n = 6) from post-treatment day (PTD) 1-7, with greatest difference seen on PTD7 (12.9 vs. 42.6, p = 0.07). HP analysis showed reduction of TB at PTD7 with PV treatment. Conclusions: NKX101 demonstrated improvements in in vitro cytotoxicity and pro-inflammatory cytokine release. RD techniques in vivo revealed increased cell delivery and improved tumor control. Further studies are underway to confirm our initial findings and understand NKX101 cellular kinetics and susceptibility to immunosuppression in the liver, along with planned clinical evaluation in Phase 1 trials.

Improved trafficking and tumor control with regional, pressure-enabled drug delivery of anti-CEA CAR-T cells for colorectal liver metastases in a murine model

Introduction

Efficacy of cellular immunotherapy for liver metastases (LM) has been limited by poor trafficking and elevated intra-tumoral pressures. In a phase 1b study, we found that regional, pressure-enabled drug delivery (PEDD, TriSalus Life Sciences, Inc.) improved LM CAR-T delivery. We hypothesized that PEDD of CAR-T in a murine model can improve LM control.

Methods

LM bearing CD45.2 mice were treated with CD45.1 anti-CEA CAR-T via systemic delivery (SD, tail vein) or regional delivery (RD, portal vein) at low pressure (LPRD) vs. high pressure (HPRD) to model PEDD. Flow rates were calibrated to achieve LPRD or HPRD. Tumor bioluminescence (TB), flow cytometry (FC), immunofluorescence (IF), & quantitative polymerase chain reaction (qPCR) were assessed on various post-treatment days (PTD).

Results

FC of liver non-parenchymal cells on PTD7 showed increased CAR-T density in HPRD & LPRD (9.4% & 11.0%, p = 0.03 & 0.002) vs. SD (3.7%). qPCR of the CAR transgene supported this observation, but was not significant (HPRD 135.8, p = 0.76, LPRD 108.6, p = 0.40 vs. SD 69.8). TB was lower in RD vs. SD up to PTD7 (log2 fold-change HPRD −1.3 & LPRD −0.9 vs. SD 4.3, p = 0.005 & 0.006). Tumor proliferation by Ki67 IF was significantly reduced with RD vs. control (HPRD & LPRD, p &lt; 0.001 & p = 0.05) with HPRD superior to LPRD (p = 0.03). Serum liver enzymes were not significantly elevated using HPRD vs. LPRD at PTD7 (AST/ALT 154.7/36.3 vs. 139.1/29.1, p = 0.84/0.67), but did rise at PTD17, correlating with tumor progression (AST/ALT 800.7/229.3 vs. 387.5/139.5, p = 0.10/0.28).

Conclusions

RD increased LM CAR-T delivery and HPRD showed evidence of improved CAR-T trafficking and tumor control relative to LPRD. Further clinical testing of PEDD is planned for LM cellular therapy.

Comparison of gemcitabine delivery and tumor response in a pressurized pancreatic retrograde venous infusion versus systemic infusion in an orthotopic murine model

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Background: Pancreatic ductal adenocarcinoma (PDAC) is associated with limited response to systemic therapy (ST). Elevated tumor interstitial fluid pressures (IFP) inhibit penetration of ST. Regional Pressure Enabled Drug Delivery has recently demonstrated improved response for liver tumors in a clinical trial. However, this delivery method has not been evaluated in PDAC. We compared gemcitabine (Gem) by systemic delivery vs. a novel pressurized Pancreatic Retrograde Venous Infusion (PRVI) method in an orthotopic PDAC mouse model. Methods: PDAC murine cell line (KPC4580P) tumors were transplanted onto the pancreatic tail of C57BL/6J mice. Groups of 15 mice were randomly assigned to PRVI Gem, PRVI saline (Control), or intraperitoneal Gem (Systemic) groups. Five mice from the PRVI and Systemic groups were randomly selected after one hour post infusion to evaluate Gem tumor concentrations by liquid chromatography - tandem mass spectrometry (ng/mg), and the remainder of mice were euthanized after 7 days to evaluate treatment response. Results: Tumor concentrations of Gem were significantly higher following PRVI compared to Systemic (128 vs. 19, p < 0.01) at one hour after treatment. Seven days after treatment, PRVI Gem mice demonstrated lower mean tumor volume (mm3) than Systemic Gem and Control mice (274 vs. 857 vs. 629, p < 0.01), respectively. Histologic evaluation of tumors demonstrated decreased cellularity in the PRVI Gem mice compared to Systemic and Control mice (35 vs. 78 vs. 71%, p = 0.01), respectively. No differences were seen in Ki67% or immune cell infiltrate between groups. Conclusions: PRVI delivery resulted in increased PDAC Gem concentrations and improved treatment responses with decreased tumor burden and cellularity. These findings suggest that pressurized regional chemotherapy infusion overcomes the elevated PDAC IFP and justifies additional translational pre-clinical studies with other chemotherapeutics (including immunomodulating antibodies) with different physicochemical properties.

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.

Trends in Incidence and Factors Affecting Survival of Patients With Cholangiocarcinoma in the United States

Background: Cholangiocarcinoma (CCA) includes cancers arising from the intrahepatic and extrahepatic bile ducts. The etiology and pathogenesis of CCA remain poorly understood. This is the first study investigating both incidence patterns of CCA from 1973 through 2012 and demographic, clinical, and treatment variables affecting survival of patients with CCA. Patients and Methods: Using the SEER database, age-adjusted incidence rates were evaluated from 1973-2012 using SEER*Stat software. A retrospective cohort of 26,994 patients diagnosed with CCA from 1973-2008 was identified for survival analysis. Cox proportional hazards models were used to perform multivariate survival analysis. Results: Overall incidence of CCA increased by 65% from 1973-2012. Extrahepatic CCA (ECC) remained more common than intrahepatic CCA (ICC), whereas the incidence rates for ICC increased by 350% compared with a 20% increase seen with ECC. Men belonging to non-African American and non-Caucasian ethnicities had the highest incidence rates of CCA. This trend persisted throughout the study period, although African Americans and Caucasians saw 50% and 59% increases in incidence rates, respectively, compared with a 9% increase among other races. Median overall survival (OS) was 8 months in patients with ECC compared with 4 months in those with ICC. Our survival analysis found Hispanic women to have the best 5-year survival outcome (P<.0001). OS diminished with age (P<.0001), and ECC had better survival outcomes compared with ICC (P<.0001). Patients who were married, were nonsmokers, belonged to a higher income class, and underwent surgery had better survival outcomes compared with others (P<.0001). Conclusions: This is the most up-to-date study of CCA from the SEER registry that shows temporal patterns of increasing incidence of CCA across different races, sexes, and ethnicities. We identified age, sex, race, marital status, income, smoking status, anatomic location of CCA, tumor grade, tumor stage, radiation, and surgery as independent prognostic factors for OS in patients with CCA.

Regional pressure-enabled drug delivery of anti-PD-1 agent for colorectal liver metastases improves anti-tumor activity without increased hepatic toxicity

Introduction

Checkpoint inhibitors (CI) have greatly impacted the treatment of solid tumors. Success in the liver has been more limited. When intravenously infused, the CI is delivered predominantly to extrahepatic sites, which results in systemic side effects. Previously, we reported on regional delivery of cellular immunotherapy for liver tumors using pressure-enabled drug delivery (PEDD™, TriSalus™ Life Sciences, Inc.). We hypothesized that PEDD of CI would improve the therapeutic index (TI).

Methods

In a murine model of colorectal liver metastases (CRLM), we infused high (HP) or low pressure (LP) anti-PD-1 antibodies (RMP1-14) via the portal vein and compared to systemic tail vein delivery (SD) at 0, 0.3, 1.0 and 3.0 mg/kg. Tumor bioluminescence (TB), histopathology, and serologic analysis informed treatment effects and toxicity.

Results

At a dose of 3mg/kg, LP resulted in similar IVIS TB growth kinetics compared to SD 3 mg/kg at 7 days post-treatment (geometric mean, p = 0.94). In animals treated with a 10-fold lower dose (0.3 mg/kg), tumor growth was significantly lower with HP vs. LP (7.5-fold improvement, p = 0.04). Circulating serum anti-PD-1 levels were similar when we compared SD and LP at 1 and 3 mg/kg (Mean 2512.0 vs. 2250.2 ng/mL, p = 0.25). Comparatively, systemic exposure was significantly lower at 0.3 mg/kg LP (Mean 508.1 ng/mL, p &lt; 0.0001). No increases in hepatotoxicity were seen with PEDD (AST p = 0.57, ALT p = 0.43).

Conclusion

PEDD of anti-PD-1 CI improved liver tumor control while also limiting systemic exposure. These findings support PEDD for anti-PD-1 therapy to improve TI. Phase 1 exploration of anti-PD-1 PEDD for patients with hepatic malignancy is thus warranted.

Pressure enabled drug delivery of anti-CEA CAR-T cells increases intra-hepatic CAR-T tumor penetration and therapeutic index in a murine model of liver metastasis

Introduction

We have demonstrated safety and clinical activity with anti-CEA CAR-T (Sorrento/TNK Therapeutics, Inc.) regional infusions for treatment of liver metastases (LM) using a pressure-enabled drug delivery device (PEDD™, TriSalus™ Life Sciences, Inc.) to increase CAR-T penetration. To further explore the potential benefit of PEDD, we developed a pre-clinical murine LM model that enables correlation of infusion pressure with response.

Methodology

Mice with CEA+ LM were infused with anti-CEA CAR-T into the portal vein with specified rate and pressure levels. Flow cytometry (FC), bioluminescence imaging (BLI), and serum liver function tests (LFTs) were conducted at multiple time points.

Results

Flow-pressure relationship was established with ΔP of 7.23 mmHg vs 2.33 mmHg (p=0.01) in high-pressure (10 mL/min, HP) and low-pressure (1 mL/min, LP) cohorts. FC assessment of hepatic non-parenchymal cells 1d after infusion demonstrated 15.9% CD3+CAR+ in HP, compared to 5.1% in LP (p=0.0004). Tumor BLI at day 3 (geometric mean relative to baseline) showed significantly enhanced therapeutic effect in HP, −18% relative signal intensity (RSI), compared to +148% RSI in LP (p=0.05) or +178% RSI in controls (p=0.04). LFTs were similar in LP and HP groups with AST 302 vs 437 U/L (p=0.60) and total bilirubin 0.25 vs 0.7 mg/dL (p=0.33), respectively.

Conclusions

HP delivery correlated with enhanced CAR-T delivery and control of tumor growth, without an increase in liver toxicity. Follow up to this proof of concept study will investigate multiple infusions with combinatorial approaches with the goal of durable tumor eradication. An ongoing clinical study will further explore CAR-T PEDD in patients.

STAT3 inhibition induces Bax-dependent apoptosis in liver tumor myeloid-derived suppressor cells

Immunosuppressive myeloid-derived suppressor cells (MDSC) subvert antitumor immunity and limit the efficacy of chimeric antigen receptor T cells (CAR-T). Previously, we reported that the GM-CSF/JAK2/STAT3 axis drives liver-associated MDSC (L-MDSC) proliferation and blockade of this axis rescued antitumor immunity. We extended these findings in our murine liver metastasis (LM) model, by treating tumor-bearing mice with STAT3 inhibitors (STATTIC or BBI608) to further our understanding of how STAT3 drives L-MDSC suppressive function. STAT3 inhibition caused significant reduction of tumor burden as well as L-MDSC frequencies due to decrease in pSTAT3 levels. L-MDSC isolated from STATTIC or BBI608-treated mice had significantly reduced suppressive function. STAT3 inhibition of L-MDSC was associated with enhanced antitumor activity of CAR-T. Further investigation demonstrated activation of apoptotic signaling pathways in L-MDSC following STAT3 inhibition as evidenced by an upregulation of the pro-apoptotic proteins Bax, cleaved caspase-3, and downregulation of the anti-apoptotic protein Bcl-2. Accordingly, there was also a decrease of pro-survival markers, pErk and pAkt, and an increase in pro-death marker, Fas, with activation of downstream JNK and p38 MAPK. These findings represent a previously unrecognized link between STAT3 inhibition and Fas-induced apoptosis of MDSCs. Our findings suggest that inhibiting STAT3 has potential clinical application for enhancing the efficacy of CAR-T cells in LM through modulation of L-MDSC.

Early Investigations and Recent Advances in Intraperitoneal Immunotherapy for Peritoneal Metastasis

Peritoneal metastasis (PM) is an advanced stage malignancy largely refractory to modern therapy. Intraperitoneal (IP) immunotherapy offers a novel approach for the control of regional disease of the peritoneal cavity by breaking immune tolerance. These strategies include heightening T-cell response and vaccine induction of anti-cancer memory against tumor-associated antigens. Early investigations with chimeric antigen receptor T cells (CAR-T cells), vaccine-based therapies, dendritic cells (DCs) in combination with pro-inflammatory cytokines and natural killer cells (NKs), adoptive cell transfer, and immune checkpoint inhibitors represent significant advances in the treatment of PM. IP delivery of CAR-T cells has shown demonstrable suppression of tumors expressing carcinoembryonic antigen. This response was enhanced when IP injected CAR-T cells were combined with anti-PD-L1 or anti-Gr1. Similarly, CAR-T cells against folate receptor α expressing tumors improved T-cell tumor localization and survival when combined with CD137 co-stimulatory signaling. Moreover, IP immunotherapy with catumaxomab, a trifunctional antibody approved in Europe, targets epithelial cell adhesion molecule (EpCAM) and has shown considerable promise with control of malignant ascites. Herein, we discuss immunologic approaches under investigation for treatment of PM.

Glycogen synthase kinase 3 inhibition lowers PD-1 expression, promotes long-term survival and memory generation in antigen-specific CAR-T cells

Successful remission in hematological cancers by CAR-T cell immunotherapy has yet to be replicated in solid tumors like GBM. A significant impediment of CAR-T immunotherapy in solid tumors is poor exposure of T cells to tumor antigens resulting in suboptimal CAR-T cell activation, which ultimately fails to induce a robust anti-tumor immune response. Costimulatory moieties in advanced-generation CARs, along with additional IL2 therapy has been shown to be insufficient to overcome this hurdle and have its cytotoxic limitations. GSK3 is constitutively active in naïve T cells and is transiently inactivated during T cell activation resulting in rapid T cell proliferation. Pharmacologic inhibition of GSK3 in GBM-specific CAR-T cells reduced FasL expression, increased T cell proliferation and reduced exhaustion by lowering PD-1 levels resulting in the development of CAR-T effector memory phenotype. Treatment with GSK3-inhibited CAR-T cells resulted in 100% tumor elimination during the tumor-rechallenge experiment in GBM-bearing animals and increased accumulation of memory CAR-T cells in secondary lymphoid organs. These adjuvant-like effects of GSK3 inhibition on activated CAR-T cells may be a valuable adjunct to a successful implementation of CAR-T immunotherapy against GBM and other solid tumors.

Liver-specific programming of myeloid cells promotes intrahepatic immunosuppression

Liver is a tolerogenic organ and has variety of immune cells resulting in a profoundly immunosuppressive space. We recently reported that GM-CSF/JAK2/STAT3 axis drives liver myeloid suppressor cell (L-MDSC) proliferation and STAT3 inhibition causes activation of apoptosis signaling via Bax up-regulation. Herein, we explore liver specific programming events that promote L-MDSC suppressive conditioning. Bone marrow derived MDSC (BM-MDSC) were expanded in CD45.1+ mice in response to intraperitoneal MC38 tumors. CD45.1+ BM-MDSC were adoptively transferred into CD45.2+ recipient mice via tail vein (TV) or portal vein (PV). CD11b+ cells were harvested 48 hrs later from recipient liver and lungs. Liver from PV and lung from TV CD45.1+ MDSC recipients were compared. There was increased expansion of CD45.1+ MDSC (CD11b+Gr1+) in PV-liver as compared to TV-lung group (Liver-PV 45±3% vs. Lung-TV 15±2% vs. Tumor 43±3, p&lt;0.001, n=5) with increased numbers of the more immunosuppressive monocytic MDSC (M-MDSC) subtype in CD45.1+ transferred cells in liver as compared to lung (Liver-PV 61±4%, Lung-TV 40±3%, Tumor 58±3 p&lt;0.005, n=5). Enhanced pSTAT3 expression (mediator of MDSC expansion) in CD45.1+CD11b+Gr1+ cells in liver was observed as compared to lung (pSTAT3: Liver-PV 54±4, Lung-TV 30±5, p&lt;0.05 n=5). Quantitative PCR of MDSCs isolated from Liver-PV showed significantly decreased levels (8.5 fold, p&lt;0.05, n=4) of pro-apoptotic Bax protein as compared to Lung-TV indicating MDSC apoptosis resistance following conditioning in the liver. These data indicate that L-MDSCs are directed towards suppressive programming and blocking STAT3 may have clinical application for enhancing the efficacy of immunotherapy for liver tumors.

Abstract CT109: HITM-SIR: Phase Ib trial of CAR-T hepatic artery infusions and selective internal radiation therapy for liver metastases

OBJECTIVES: There are no effective treatment options for patients with unresectable CEA+ liver metastases (LM) from gastrointestinal adenocarcinoma refractory to conventional systemic therapy. In the previous Hepatic Immunotherapy for Metastases (HITM) phase I study we demonstrated the safety and biologic activity of anti-CEA CAR-T cell hepatic artery infusions (HAI). HITM-SIR was a single arm phase Ib trial testing anti-CEA CAR-T HAI followed by selective internal radiation therapy (SIRT) in patients with refractory CEA+ LM.

METHODOLOGY: We enrolled 8 patients with unresectable, chemotherapy refractory CEA+ LM and 6/8 completed the study. Two patients were withdrawn for disease progression prior to CAR-T infusion and biliary obstruction due to centrally located disease. Limited extrahepatic disease (EHD) was permitted. Subjects received 3 HAI of anti-CEA CAR-T cells (1e10 cells per dose) along with low dose continuous IL-2 infusions (50,000 IU/kg/day). SIRT was administered in standard fashion 2 weeks following the 3rd CAR-T HAI. Primary objective was to establish safety of the CAR-T/SIRT combination. Secondary objectives included response assessed by modified RECIST (mRECIST), immune-related response criteria (irRC), and tumor marker kinetics.

RESULTS: The mean age for enrolled subjects was 54.6 years (39-61) with 3 women and 5 men. Histologies (completed patients): 2 colon, 2 rectal, and 2 pancreas. This heavily pre-treated, advanced disease group of patients received an average of 2.3 lines of prior chemotherapy, 3/6 had &gt;10 LM, and the average largest LM size was 7.3 cm. The average transduction efficiency as measured by CAR expression was 60.4%, with 90.9% viability, and an average production time for &gt;3e10 cells of 13.8 days. There were no grade (G) 4/5 events related to the CAR-T, SIRT, or combination. Toxicities included G 1/2 liver function test elevations (n=5/6), fever (n=5/6), hypereosinophilia (n=2/6), and edema (n=2/6). G3 toxicities included colitis (n=2/6), fever (n=2/6), and edema (n=2/6). One patient experienced a hypertensive crisis during a single CAR-T infusion but tolerated 2 infusions without incident. All colitis episodes resolved with IL-2 dose reductions. Post-SIRT serum CEA decreases were noted in 2/6 patients (-40% and -71%) with CA19-9 decreases in 2/5 detectable patients (-31% and -32%). When considering all on-study time points, 5/6 patients had CEA responses (mean decrease 59.7%) and 4/5 patients expressing CA 19-9 decreases (mean 59.6%). At completion of the study, 3/6 patients had stable disease (SD) in the liver by mRECIST and irRC, and 3/6 SD overall by irRC. Target liver lesion decreases in size among patients with SD ranged from 6-28%. Regression of extrahepatic tumors or abscopal effects were noted in 2/6 at lung and bone sites. One patient remains without evidence of viable liver disease at 10.8 months follow-up. The median overall survival time for all patients is 6.9 months (range 3.8-10.8+).

CONCLUSIONS: Following this phase Ib trial, the recommended phase 2 dose for anti-CEA CAR-T HITM infusions is 1010 cells with or without SIRT. The favorable safety profile and evidence of biologic activity indicate that CAR-T HITM infusions should be further studied in a phase 2 trial. Clinical trial information: NCT02416466.

Citation Format: Steven C. Katz, Ethan Prince, Marissa Cunetta, Prajna Guha, Ashley Moody, Vincent Armenio, Li J. Wang, N. Joseph Espat, Richard P. Junghans. HITM-SIR: Phase Ib trial of CAR-T hepatic artery infusions and selective internal radiation therapy for liver metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT109. doi:10.1158/1538-7445.AM2017-CT109

Association of primary tumor lymph node ratio with burden of liver metastases and survival in stage IV colorectal cancer

BACKGROUND

The primary objective of our study was to assess the association of primary tumor lymph node ratio (LNR) in stage IV colorectal adenocarcinomas (CRC) with overall survival (OS) and the extent of metastatic disease in the liver.

METHODS

We analyzed data on 53 stage IV CRC patients who underwent surgical resection of the primary tumor. The median LNR of 0.25 was used to stratify patients into high LNR (H-LNR) and low LNR (L-LNR) groups. Statistical comparison was performed using chi square test and multiple regression models. OS was calculated using the Kaplan-Meier (KM) method while cox regression was used for multivariate analysis.

RESULTS

H-LNR status was associated with the presence of >3 liver metastases (LM) [odds ratio (OR): 2.43, P=0.047] and bilobar LM (OR: 3.94, P=0.039). The OS in H-LNR patients was significantly worse in the entire cohort compared to L-LNR (9% vs. 34% at 3 years, P=0.027). The 5-year OS in patients undergoing liver resection for LM was also significantly worse in the H-LNR group (0% vs. 37%, P=0.013). LNR was independently associated with survival on multivariate analysis [HR: 2.63; 95% confidence intervals (CI), 1.13-6.14; P=0.025].

CONCLUSIONS

In stage IV CRC, LNR is associated with the extent of hepatic tumor burden and was an independent predictor of survival in patients undergoing liver resection.

Frontline Science: Functionally impaired geriatric CAR-T cells rescued by increased α5β1 integrin expression

Chimeric antigen receptor expressing T cells (CAR-T) are a promising form of immunotherapy, but the influence of age-related immune changes on CAR-T production remains poorly understood. We showed that CAR-T cells from geriatric donors (gCAR-T) are functionally impaired relative to CAR-T from younger donors (yCAR-T). Higher transduction efficiencies and improved cell expansion were observed in yCAR-T cells compared with gCAR-T. yCAR-T demonstrated significantly increased levels of proliferation and signaling activation of phosphorylated (p)Erk, pAkt, pStat3, and pStat5. Furthermore, yCAR-T contained higher proportions of CD4 and CD8 effector memory (EM) cells, which are known to have enhanced cytolytic capabilities. Accordingly, yCAR-T demonstrated higher levels of tumor antigen-specific cytotoxicity compared with gCAR-T. Enhanced tumor killing by yCAR-T correlated with increased levels of perforin and granzyme B. yCAR-T had increased α5β1 integrin expression, a known mediator of retroviral transduction. We found that treatment with M-CSF or TGF-β1 rescued the impaired transduction efficiency of the gCAR-T by increasing the α5β1 integrin expression. Neutralization of α5β1 confirmed that this integrin was indispensable for CAR expression. Our study suggests that the increase of α5β1 integrin expression levels enhances CAR expression and thereby improves tumor killing by gCAR-T.

Regional immunotherapy for liver and peritoneal metastases

Pancreatic adenocarcinoma is a biologically aggressive disease, with liver and peritoneal metastases being a frequent cause of death. We examine how the pancreatic carcinoma microenvironment and immunosuppressive landscape favor tumor progression. Immunotherapy has shown promise in select solid tumors, yet challenges remain in applying these gains to stage IV pancreatic adenocarcinoma. We discuss how regional therapy strategies may be leveraged to open new avenues for treating pancreatic carcinoma metastases with immunotherapy.

Targeted deletion of liver myeloid derived suppressor cells by inhibition of STAT3 dependent survival pathways to rescue CAR-T function

Myeloid derived suppressor cells (MDSC) subvert anti-tumor immunity. Previously we reported that the GM-CSF/ JAK2/STAT3 axis drives liver MDSC (L-MDSC) proliferation and CAR-T suppression. We hypothesized that STAT3 supports L-MDSC survival and suppressive function by inhibiting apoptosis. We treated liver metastasis (LM) in mice with STAT3 inhibitors (STATTIC or BBI) or with vehicle control. STAT3 inhibition caused a significant reduction in tumor burden (p&lt;0.05) and L-MDSC frequency (DMSO 41±3% vs. STATTIC 29±3%/BBI 20±3%, p&lt;0.0001, n=10) in association with lower pSTAT3 levels (DMSO 33±4% vs. STATTIC 11±3%/BBI 9±2%, p&lt;0.0001, n=10). L-MDSC isolated from STATTIC or BBI treated mice were co-cultured with CAR-Ts and corresponding target tumor cells at 1:1:1 ratio. There was a significant decrease in tumor cell density (DMSO 100% vs. STATTIC 71±5%/BBI 20±3%, p&lt;0.05, n=5) and enhancement of tumor cell killing (DMSO 28±4% vs. STATTIC 54±4%/BBI 52±7%, p&lt;0.01, n=5). Rescue of CAR-T tumor killing function correlated with enhanced L-MDSC apoptosis signaling. We detected upregulation of pro-apoptotic proteins Bax, caspase 3, and Fas. Signaling molecules downstream of Fas, JNK and p38 MAPK (p&lt;0.05), were also activated in L-MDSC. In contrast, L-MDSC pro-survival Bcl2, pErk, and pAkt (p&lt;0.05) were downregulated in response to STAT3 inhibition. Microarray results confirmed the STAT3-induced changes in apoptotic and survival gene expression, which was validated by RT-PCR (p&lt;0.05). Within LM, STAT3 inhibition drove L-MDSC apoptosis via the Fas/Fas- L pathway with downstream pro-apoptotic signaling through p38 MAPK. Blocking STAT3 may have clinical application for enhancing immunotherapy for LM.

Tumor-Associated Macrophage Infiltration in Colorectal Cancer Liver Metastases is Associated With Better Outcome

BACKGROUND

Tumor-associated macrophages (TAMs) support growth in most human cancers, with the notable exception of colorectal adenocarcinoma, in which TAM infiltration of primary tumors is correlated with a better outcome. The importance of TAMs in colorectal liver metastases (CLM) is unknown.

METHODS

Using a tissue microarray of CLM resected at their institution from 1998 to 2000, the authors quantified immune marker expression by immunohistochemistry (IHC) using Metamorph Image Analysis software. Findings showed that CD68, CD3, CD4, CD8, FoxP3, and MHC-I were correlated with overall survival (OS) and disease-free survival (DFS).

RESULTS

Tumor cores from 158 patients were analyzed. The median follow-up period was 117 months for survivors (n = 39). The univariate analysis showed a significant positive association between DFS and CD4⁺ (p = 0.025) and CD68⁺ (p = 0.007). The findings showed a significant positive correlation of OS with CD4⁺ (p = 0.042), whereas the correlation with CD68⁺ was not significant (p = 0.17). Cutoffs were determined to dichotimize each marker for the highest log-rank statistic. Patients with CD4^high had a median OS of 115 months and DFS of 41 months (p = 0.007 compared with 40 and 16 months, respectively, for patients with CD4^low (p = 0.022). Patients with CD68^high had a median OS of 50 months and a median DFS of 25 months (p = 0.67) compared with 43 and 15 months (p = 0.028). In the multivariate analysis of factors affecting DFS, high CD68 was associated with longer DFS (hazard ratio [HR], 0.63, 95% confidence interval [CI], 0.43-0.94; p = 0.02), independently of clinicopathologic variables and CD4.

CONCLUSIONS

High TAM infiltration in resected CLM is associated with better outcome, independently of known clinicopathologic and immune predictors. This suggests that TAM depletion, which is being tested clinically in other cancers, may be detrimental in CLM.

Mincle Signaling Promotes Con A Hepatitis

Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPβ and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ-related signaling intermediates C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPβ and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation.

Abstract 2212: Induction of α5β1 integrin expression rescues geriatric CAR-T cell function

Chimeric antigen receptors expressing T cells (CAR-Ts) are a promising form of immunotherapy for solid tumors. The majority of cancer patients in the United States are over 65 years old. The impact of age-related physiologic changes on cancer therapy and immunotherapy in particular require further study. We tested our hypothesis that CAR-T from geriatric donors (gCAR-T, n = 8, &gt;65 years) are functionally impaired relative to CAR-T from younger donors (yCAR-T, n = 8, 18-45 years). T cells were genetically modified to express CAR specific for carcino-embryonic antigen (CEA), presently in use in our phase I trials. CAR-T cells were expanded ex vivo with IL2 (3000IU/ml) or IL15 (5ng/ml) for 20 days. Higher transduction efficiencies (36.9%+4.3 yCAR-T vs 21.3%+2.2 gCAR-T, p = 0.002) and improved cell expansion (2.5 fold in IL2, p = 0.01, two-tailed t-test) were observed in yCAR-T cells compared to gCAR-T. To define the underlying signaling mechanisms that led to increased proliferation in yCAR-T cells, we examined pERK, pAKT, pSTAT3 and pSTAT5. Following activation with anti-CD3, yCAR-T demonstrated significantly increased levels of pERK (13.4 fold in IL2, p = 0.03 and 2.3 fold in IL15, p = 0.04), pAKT (4.2 fold in IL2, p = 0.04 and 3.0 fold in IL15, p = 0.04), pSTAT3 (1.5 fold in IL2, p = 0.02 and 2.9 fold in IL15, p = 0.01) and pSTAT5 (5.7 fold in IL2, p = 0.02 and 2.1 fold in IL15, p = 0.03) compared to gCAR-T. Furthermore, yCAR-T contained higher proportions of CD4 effector cells (EC) (p = 0.003), CD4 effector memory (EM) cells (p = 0.002) and CD8 effector memory cells (EM) (p = 0.002). In accordance with higher numbers of CD4 and CD8 EM, yCAR-T demonstrated higher levels of CEA specific cytotoxicity compared to gCAR-T (1.3-fold over gCAR-T, p = 0.03), with maximum cytotoxicity observed in IL15 treated yCAR-T cells. Enhanced tumor killing by yCAR-T correlated with increased levels of perforin (1.3+0.1 ng/ml, p = 0.01) and granzyme B (0.4+0.03 ng/ml, p = 0.02). Unmodified geriatric T cells (gT) had decreased α5β1 integrin expression as compared to unmodified young T cells (yT) (yT cells 44.4 +4.2 vs gT cells 22.3 +2.0, p = 0.0003), a known mediator of retroviral transduction. We found that M-CSF or TGF-β1 rescued CAR expression by gCAR-T (yCAR-T 36.9+4.3, gCAR-T 29.9+1.0, gT+M-CSF 41.4+1.0, gT+TGF-β1 40.1+2.0, p&lt;0.002 vs gCAR-T) through restoring α5β1 integrin expression (gT cells +M-CSF 41.0+1.0, gT cells + TGF- β1 31.8+1.4, yT cells 44.41 +4.2, p&lt;0.0005). We performed cytotoxicity assays and demonstrated that M-CSF and TGF-β1 (up to 1.5 fold over untreated gCAR-T, p&lt;0.05) rescued g-CAR-T tumor killing function. Our study suggests that functional impairment of gCAR-T can be mitigated through M-CSF of TGF-β1 treatment to restore α5β1 integrin expression.

Citation Format: Prajna Guha, Marissa Cunetta, Ponnandai Somasundar, N J. Espat, Richard P. Junghans, Steven C. Katz. Induction of α5β1 integrin expression rescues geriatric CAR-T cell function. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2212.

Predictors of surgical non-referral for colorectal liver metastases

BACKGROUND

Surgical resection is the only curative option for patients with colorectal liver metastases (CRLM). The objective of our study was to identify factors associated with failure to refer patients with CRLM to a surgeon with oncologic and hepatobiliary expertise.

MATERIALS AND METHODS

Data were retrospectively reviewed on 75 patients with CRLM treated at our institution. Patients were divided into referred and nonreferred groups for comparison. Quantitative assessment of association was tabulated using the odds ratio (OR). Statistical comparison was performed using the chi-square test and multiple regression models. Overall survival (OS) was calculated using the Kaplan-Meier method. Multivariate analysis was done using Cox regression.

RESULTS

Factors independently associated with lower surgical referral rates included age ≥ 65 y (OR 0.29, 95% confidence interval [CI] 0.09-0.89, P = 0.032), bilobar CRLM (OR 0.35, 95% CI 0.09-0.97, P = 0.048), and presence of >3 CRLM (OR 0.33, 95% CI 0.11-0.94, P = 0.044). The 5-y OS for referred patients was 33% compared with only 8% in patients who were not referred (P < 0.001). Factors independently associated with worse OS included age ≥ 65 y (hazard ratio [HR] 2.01, 95% CI 1.12-3.59, P = 0.019), bilobar hepatic metastases (HR 3.04, 95% CI 1.62-5.70, P < 0.001), and the presence of extrahepatic metastases (HR 2.11, 95% CI 1.02-4.16, P = 0.011). Referral to a surgeon was associated with improved OS (HR 0.42, 95% CI 0.24-0.74, P = 0.003).

CONCLUSIONS

Failure to refer CRLM patients for surgical evaluation is associated with aggressive biologic features that do not necessarily preclude resection. Determination of resectability should be made with input from appropriately trained surgical experts.

The impact of age on nodal metastases and survival in gastric cancer

BACKGROUND

In gastric adenocarcinoma, the disparity in lymph node involvement between different age groups has not been thoroughly investigated. The objective of our study was to compare age-associated differences in adequate lymph node harvest and nodal involvement in gastric adenocarcinoma patients.

METHODS

We analyzed data extracted from the Surveillance, Epidemiology and End Results database on 13,165 patients diagnosed with stage I-III gastric adenocarcinoma between 2004 and 2011. All patients underwent surgical resection. Statistical comparisons between various age groups were done using the chi-square test and Cox regression.

RESULTS

Among 13,165 gastrectomy patients, proportion of patients that had >15 lymph nodes examined decreases significantly with increasing age (P < 0.0001). When adequately staged, older patients had a significantly lower proportion of node-positive tumors (P < 0.0001). Adequate nodal staging was also associated with improved 5-y disease-specific survival across all age groups.

CONCLUSIONS

In gastric adenocarcinoma, older patients are less likely to be adequately staged. However, when adequately staged, they are less likely to have node-positive tumors. Adherence to national guidelines, regardless of age, is associated with improved survival outcomes and may alter multimodality management of gastric cancer in the elderly.

Gastrointestinal stromal tumour metastatic to the epididymis

Gastrointestinal stromal tumours (GIST) are mesenchymal neoplasms with a propensity to metastasise to the liver and peritoneal cavity. Since the advent of tyrosine kinase inhibitors, outcomes for patients with metastatic GIST have improved dramatically. Secondary to the longevity in survival, patients may develop metastatic disease in very unusual locations, which poses significant diagnostic dilemmas and management challenges. We report a case of a patient with GIST who presented with an epididymal metastasis manifesting as a scrotal mass. Resistance to targeted medical therapies continues to pose a challenge, and our case highlights the importance of a multidisciplinary approach in such patients, including long-term follow-up.

Phase I Hepatic Immunotherapy for Metastases Study of Intra-Arterial Chimeric Antigen Receptor-Modified T-cell Therapy for CEA+ Liver Metastases

PURPOSE

Chimeric antigen receptor-modified T cells (CAR-T) have demonstrated encouraging results in early-phase clinical trials. Successful adaptation of CAR-T technology for CEA-expressing adenocarcinoma liver metastases, a major cause of death in patients with gastrointestinal cancers, has yet to be achieved. We sought to test intrahepatic delivery of anti-CEA CAR-T through percutaneous hepatic artery infusions (HAIs).

EXPERIMENTAL DESIGN

We conducted a phase I trial to test HAI of CAR-T in patients with CEA(+) liver metastases. Six patients completed the protocol, and 3 received anti-CEA CAR-T HAIs alone in dose-escalation fashion (10(8), 10(9), and 10(10) cells). We treated an additional 3 patients with the maximum planned CAR-T HAI dose (10(10) cells × 3) along with systemic IL2 support.

RESULTS

Four patients had more than 10 liver metastases, and patients received a mean of 2.5 lines of conventional systemic therapy before enrollment. No patient suffered a grade 3 or 4 adverse event related to the CAR-T HAIs. One patient remains alive with stable disease at 23 months following CAR-T HAI, and 5 patients died of progressive disease. Among the patients in the cohort that received systemic IL2 support, CEA levels decreased 37% (range, 19%-48%) from baseline. Biopsies demonstrated an increase in liver metastasis necrosis or fibrosis in 4 of 6 patients. Elevated serum IFNγ levels correlated with IL2 administration and CEA decreases.

CONCLUSIONS

We have demonstrated the safety of anti-CEA CAR-T HAIs with encouraging signals of clinical activity in a heavily pretreated population with large tumor burdens. Further clinical testing of CAR-T HAIs for liver metastases is warranted.

Liver myeloid-derived suppressor cells expand in response to liver metastases in mice and inhibit the anti-tumor efficacy of anti-CEA CAR-T

Chimeric antigen receptor-modified T cell (CAR-T) technology, a promising immunotherapeutic tool, has not been applied specifically to treat liver metastases (LM). While CAR-T delivery to LM can be optimized by regional intrahepatic infusion, we propose that liver CD11b+Gr-1+ myeloid-derived suppressor cells (L-MDSC) will inhibit the efficacy of CAR-T in the intrahepatic space. We studied anti-CEA CAR-T in a murine model of CEA+ LM and identified mechanisms through which L-MDSC expand and inhibit CAR-T function. We established CEA+ LM in mice and studied purified L-MDSC and responses to treatment with intrahepatic anti-CEA CAR-T infusions. L-MDSC expanded threefold in response to LM, and their expansion was dependent on GM-CSF, which was produced by tumor cells. L-MDSC utilized PD-L1 to suppress anti-tumor responses through engagement of PD-1 on CAR-T. GM-CSF, in cooperation with STAT3, promoted L-MDSC PD-L1 expression. CAR-T efficacy was rescued when mice received CAR-T in combination with MDSC depletion, GM-CSF neutralization to prevent MDSC expansion, or PD-L1 blockade. As L-MDSC suppressed anti-CEA CAR-T, infusion of anti-CEA CAR-T in tandem with agents targeting L-MDSC is a rational strategy for future clinical trials.

Chemotherapy does not adversely impact outcome following post-incisional hernia repair with biomaterial mesh

Background

Patients receiving chemotherapy are at increased risk for developing recurrent or post‐incisional hernias (PIH). Biological materials are an alternative to synthetic mesh in contaminated fields. The impact of chemotherapy on biomaterial tissue ingrowth and integration has not been well studied.

Methods

From 2008 to 2011 patients who underwent PIH repair with biomaterial mesh (Biodesign®) were selected. Patients were divided into two groups: those receiving chemotherapy (CT) and those not receiving chemotherapy (NCT).

Results

Forty‐five patients were identified, 28 (62%) in the NCT group and 17 (38%) in the CT group. Median follow up for NCT and CT groups were 27 and 17 months, respectively. A total of 9/45 (20%) surgical site infections (SSI) were diagnosed, with 6/28 (21%) in the NCT and 3/17 (18%) in the CT group (P = 0.53). Seroma formation was seen in 5/28 (18%) of NCT patients and 4/17 (23%) in CT group (P = 0.46). Overall hernia recurrence rate was 22%, and the rates of recurrence were similar among the CT 3/17 (18%) and NCT 7/28 (25%) groups (P = 0.42).

Conclusion

The use of perioperative chemotherapy did not increase the rate of wound complications following PIH repair with biologic mesh in this group of patients. J. Surg. Oncol. 2015 111:725–728. © 2015 The Authors. Journal of Surgical Oncology Published by Wiley Periodicals, Inc.

Neutrophil:lymphocyte ratios and serum cytokine changes after hepatic artery chimeric antigen receptor-modified T-cell infusions for liver metastases

Introduction

Our phase I Hepatic Immunotherapy for Metastases (HITM) trial tested the safety of chimeric antigen receptor modified T cell (CAR-T) hepatic artery infusions (HAI) for unresectable CEA+ liver metastases (LM). High neutrophil:lymphocyte ratios (NLR) predict poor outcome in cancer patients and we hypothesized that NLR changes would correlate with early responses to CAR-T HAI.

Methods

Six patients completed the protocol. Three patients received CAR-T HAI in dose escalation (1 × 10⁸, 1 × 10⁹, and 1 × 10¹⁰cells) and the remainder received 3 doses (1 × 10¹⁰ cells) with IL2 support. Serum cytokines and NLR were measured at multiple time points.

Results

The mean NLR for all patients was 13.9 (range 4.8-38.1). NLR increased in four patients following treatment with a mean fold change of 1.9. Serum IL6 levels and NLR fold-changes demonstrated a trend towards a positive correlation (r=0.77, p=0.10). Patients with poor CEA responses were significantly more likely to have higher NLR level increases (p=0.048).

Conclusions

Increased NLR levels were associated with poor responses following CAR-T HAI. NLR variations and associated cytokine changes may be useful surrogates of response to CAR-T HAI.

The prognostic value of liver tumor T cell infiltrates

Tumor infiltrating lymphocytes (TIL) have been demonstrated to predict oncologic outcomes following resection of primary intrahepatic neoplasms and metastatic liver tumors. Despite strong immunosuppressive factors within the intrahepatic space, TIL are frequently demonstrated in liver tumors. The presence of TIL within liver tumors provides evidence of a host immune response that may be protective, but often is rendered ineffective by tumor induced immune dysfunction. In this review, we discuss techniques involved in studying TIL and subsets of TIL commonly identified. We emphasize the unique nature of the intrahepatic milieu that promotes immunosuppression, and how liver TIL and TIL ratios can be used as indicators of prognosis. Several types of primary and metastatic liver tumors are considered to highlight the similarities and important differences in TIL responses, which likely reflect how intrahepatic immunity is influenced by tumor biology. The studies we discuss indicate that tumor infiltration by suppressor cells and expression of immunoinhibitory molecules by TIL limits the anti-tumor immune function of effector T cells. Most patients fail to mount an adequate immune response to liver tumors, which provides compelling rationale for clinical study of immunotherapy for intrahepatic neoplasms.

Liver metastases induce reversible hepatic B cell dysfunction mediated by Gr-1+CD11b+ myeloid cells

LM escape immune surveillance, in part, as a result of the expansion of CD11b+MC, which alter the intrahepatic microenvironment to promote tumor tolerance. HBC make up a significant proportion of liver lymphocytes and appear to delay tumor progression; however, their significance in the setting of LM is poorly defined. Therefore, we characterized HBC and HBC/CD11b+MC interactions using a murine model of LM. Tumor-bearing livers showed a trend toward elevated absolute numbers of CD19+ HBC. A significant increase in the frequency of IgM(lo)IgD(hi) mature HBC was observed in mice with LM compared with normal mice. HBC derived from tumor-bearing mice demonstrated increased proliferation in response to TLR and BCR stimulation ex vivo compared with HBC from normal livers. HBC from tumor-bearing livers exhibited significant down-regulation of CD80 and were impaired in inducing CD4(+) T cell proliferation ex vivo. We implicated hepatic CD11b+MC as mediators of CD80 down-modulation on HBC ex vivo via a CD11b-dependent mechanism that required cell-to-cell contact and STAT3 activity. Therefore, CD11b+MC may compromise the ability of HBC to promote T cell activation in the setting of LM as a result of diminished expression of CD80. Cross-talk between CD11b+MC and HBC may be an important component of LM-induced immunosuppression.

Regional hepatic therapies: an important component in the management of colorectal cancer liver metastases

The treatment of colorectal cancer liver metastases (CRLM) has evolved significantly in the last 15 years. Currently, complete surgical resection remains the only potentially curative option; unfortunately, approximately 80% of patients with CRLM are not candidates for complete tumor resection. For patients with unresectable CRLM the available treatment options were historically limited; however, the development of regional hepatic therapies (RHT) and improvement of systemic chemotherapeutic regimens have emerged as viable options to improve overall survival and quality of life for this group of patients. The selection, sequence and integration of interventions into a multi-modal approach is a complex and evolving discipline. In this article, the currently available RHT modalities for CRLM are presented as a guide to the options for clinical treatment decisions.

Hepatic PEComa: a potential pitfall in the evaluation of hepatic neoplasms

Perivascular epithelioid cell tumour (PEComa) of the liver is very uncommon and may be overlooked in the clinical and histological differential diagnosis of a liver tumour. We report the case of an incidentally discovered liver mass suspicious for hepatocellular carcinoma, which on biopsy was suggestive of a pseudocyst but after resection was found to be hepatic PEComa with some of the usual characteristics of this neoplasm as well as several less familiar features. We have also reviewed cases of hepatic PEComa from the literature in order to provide insight into recognising possible PEComa preoperatively and assessing its risk of malignancy after diagnosis.

Tumor MHC class I expression improves the prognostic value of T-cell density in resected colorectal liver metastases

Tumor-infiltrating lymphocytes (TIL) in colorectal cancer liver metastases (CLM) have been associated with more favorable patient outcomes, but whether MHC class I (MHC-I) expression on cancer cells affects prognosis is uncertain. Immunohistochemistry was performed on a tissue microarray of 158 patients with CLM, who underwent partial hepatectomy with curative intent. Using the antibody HC-10, which detects HLA-B and HLA-C antigens and a minority of HLA-A antigens, MHC-I expression was correlated with β-2 microglobulin (β2m; r = 0.7; P < 0.001), but not with T-cell density (r < 0.32). The median follow-up for survivors was 9.7 years. High levels of MHC-I expression in tumors concomitant with high T-cell infiltration (CD3, CD4, or CD8) best identified patients with favorable outcomes, compared with patients with one or none of these immune features. The median overall survival (OS) of patients with MHC-I(hi)CD3(hi) tumors (n = 31) was 116 months compared with 40 months for the others (P = 0.001), and the median time to recurrence (TTR) was not reached compared with 17 months (P = 0.008). By multivariate analysis, MHC(hi)CD3(hi) was associated with OS and TTR independent of the standard clinicopathologic variables. An immune score that combines MHC-I expression and TIL density may be a valuable prognostic tool in the treatment of patients with CLM.

Immunotherapy for solid tumors--a review for surgeons

Immunotherapy has evolved considerably in the last decade and is becoming an integral component of the armamentarium for the treatment of patients with advanced solid tumors. It is important for clinicians, especially surgeons, to understand the basic principles of novel immunotherapies and the immune system. This review summarizes the evolution of the most relevant immunotherapies, their mechanisms of action, the data supporting their clinical use, and integration of immunotherapy into multidisciplinary management of solid tumors. This review should serve as a primer for clinicians and surgeons to understand the rapidly evolving field of immunotherapy.

Age-related trends in utilization of the internet and electronic communication devices for coordination of cancer care in elderly patients

OBJECTIVES

In this rapidly changing electronic era, we implemented a study to define age dependent variations in access and use of internet and electronic devices in the exchange of healthcare related information (HRI) and coordination of clinical care (CCC) among elderly patients with cancer.

MATERIALS AND METHODS

Data was collected through independently completed surveys after obtaining IRB approval in a single institution cancer center over a 4-month period. Questions regarding internet access and use of electronic media to obtain health information and coordinate care were distributed. The sample was divided in two groups based upon the World Health Organization (WHO) definition of geriatric patients: <65 y/o (group A) and ≥65 y/o (group B).

RESULTS

One hundred and twenty-six surveys were analyzed with 70 patients in group A and 56 patients in group B. Access to the internet and use of email was higher in the group A (77% and 71%) vs. group B (36% and 33%, p < 0.001). The younger group felt more comfortable using the internet when compared to the older group (70% vs. 40%, p = 0.01). Patients in group B demonstrated a strong preference for paper copy based HRI and phone calls to CCC than text messages or emails (73% and 95%, p < 0.001). A transition zone between the ages of 65 and 70 years was defined to identify patients with increased reluctance to use internet and electronic devices to exchange HRI and CCC.

CONCLUSION

The data supports that there is an age-defined underutilization of internet and electronic devices to exchange HRI and CCC. Characterization of this age-dependent transition zone will enable clinicians to identify patients who may not interface well with electronic communication strategies, and to improve delivery of HRI and CCC for the elderly.

Biliary obstruction results in PD-1-dependent liver T cell dysfunction and acute inflammation mediated by Th17 cells and neutrophils

Biliary obstruction is a common clinical problem that is associated with intrahepatic inflammation and impaired immunity. PD-1 is well known to mediate T cell dysfunction but has been reported to promote and attenuate acute inflammation in various injury models. With the use of a well-established murine model of BDL, we studied the effects of intrahepatic PD-1 expression on LTC function, inflammation, and cholestasis. Following BDL, PD-1 expression increased significantly among LTCs. Increased PD-1 expression following BDL was associated with decreased LTC proliferation and less IFN-γ production. Elimination of PD-1 expression resulted in significantly improved proliferative capacity among LTC following BDL, in addition to a more immunostimulatory cytokine profile. Not only was LTC function rescued in PD-1(-/-) mice, but also, the degrees of biliary cell injury, cholestasis, and inflammation were diminished significantly compared with WT animals following BDL. PD-1-mediated acute inflammation following BDL was associated with expansions of intrahepatic neutrophil and Th17 cell populations, with the latter dependent on IL-6. PD-1 blockade represents an attractive strategy for reversing intrahepatic immunosuppression while limiting inflammatory liver damage.