bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequential monitoring of circulating stromal cells from blood is predictive of progression in NSCLC patients undergoing anti-PD-L1 therapy after definitive chemoradiation therapy.
Authors: Adams Daniel , Augustyn Alexander , He Jianzhong , Qiao Yawei , Xu Ting , Liao Zhongxing X. , Gardner Kirby P , Ali Amama , Gironda Daniel J , Tang Cha-Mei , Lin Steven H. 
Published: May 2020

3051 Background: Cancer Associated Macrophage-Like cells (CAMLs) are a recently described circulating stromal cell common in the peripheral blood of patients with solid tumors. In non-small cell lung carcinoma (NSCLC), patients with CAMLs ≥50µm after completion of chemoradiation therapy (CRT) have been shown to have worse progression free survival (PFS). However, with the recent addition of anti-PD-L1 therapies in conjunction with CRT as standard of care, it has never yet to be evaluated whether CAMLs remain predictive for monitoring progression in NSCLC patients post anti-PD-L1 therapy. Methods: A 2 year single blind prospective study was undertaken to test the relationship of ≥50µm CAMLs to PFS based on imaging in lung patients before and after induction of CRT and PD-L1. We recruited 104 patients with pathologically confirmed unresectable NSCLC Stage II (n = 14), Stage III (n = 83), Stage IV (n = 3), and locally recurrent disease (n = 4). Baseline (BL) blood samples were taken prior to start of therapy. A second time point blood sample (T1) was taken at the end of radiotherapy (~40 days). A third time blood sample (T2) was taken after induction of anti-PD-L1 therapy (e.g. Imfinizi, Keytruda, etc.). Blood was filtered by CellSieve filtration and CAMLs were quantified. Analysis by CAML size of < 49 µm or ≥50 µm was used to evaluate PFS hazard ratios (HRs) by censored univariate & multivariate analysis. Results: CAMLs were found in 87% of samples averaging 2.9 CAMLs/7.5mL sample. At BL, CAMLs ≥50 µm had similar PFS to patients with < 50 µm CAMLs (HR = 1.1 95%CI 0.6-1.95 p = 0.8661). However, after CRT (T1), patients with CAML size ≥50 µm had worse PFS (HR = 3.2, 95%CI 1.8-5.8 p = 0.0002). After induction of anti-PD-L1 therapy (T2), patients with ≥50 µm CAMLs also had worse PFS (HR = 2.8 95%CI 1.5-5.4 p = 0.0037). CAML size at BL was not accurate at predicting progression within 24 months; however ≥50 µm CAMLs after CRT or after 1 cycle of anti-PDL1 therapy was 71% accurate at predicting progression of disease. Conclusions: Our data suggests that in NSCLC, ≥50 µm CAMLs after completion of CRT or appearing after induction of anti-PD-L1 therapy appears to predict progressive disease. If validated, additional studies are needed to determine if CAMLs can serve as a significantly prognostic blood based marker for predicting survival in NSCLC patients early in the treatment regime.
Anti-CTLA-4 probody BMS-986249 alone or in combination with nivolumab in patients with advanced cancers: Initial phase I results.
Authors: Gutierrez Martin , Long Georgina V. , Friedman Claire Frances , Richards Donald A. , Corr Bradley , Bastos Bruno R. , Uemura Marc Isamu , Conkling Paul R. , Moreno Victor , Edenfield William Jeffery , Becerra Carlos Roberto , Piha-Paul Sarina Anne , Peterson Amy C. , Brown Michelle , James Lee P. , Zheng Ming , Jiang Jieying , Kollia Georgia , Swijter Ailsa , Ascierto Paolo Antonio 
Published: May 2020

3058 Background: Blockade of the CTLA-4 pathway with ipilimumab (IPI) ± nivolumab (NIVO; anti–PD-1) is an effective treatment for a variety of cancers. To optimize the risk-benefit profile of CTLA-4–directed therapy, a Probody therapeutic technology platform (Pb-Tx, CytomX Therapeutics) was used to generate BMS-986249, a peptide-masked version of IPI that is unmasked by tumor-associated proteases. Pb-Tx may localize CTLA-4 activity to the tumor, minimize systemic toxicity, and allow for higher doses of anti–CTLA-4 ± anti-PD-1. In preclinical studies, BMS-986249, given at similar doses, showed comparable intratumoral and reduced peripheral pharmacodynamic activity relative to IPI (Engelhardt, AACR 2020). Here, we present the initial results of the first-in-human phase 1/2 study of BMS-986249 ± NIVO in pts with advanced (adv) cancers (NCT03369223). Methods: During dose escalation, pts received BMS-986249 at or above the approved doses of the parent molecule using a Q4W or Q8W dosing schedule as monotherapy (240–2400 mg Q4W or 1600 mg Q8W; ≈ 3–30 mg/kg vs approved 3 mg/kg Q3W IPI) or in combination (240–1200 mg Q4W or 800 mg Q8W) + NIVO 480 mg Q4W. Safety and pharmacokinetics (PK) were evaluated. Efficacy is being assessed in the dose-expansion phase. Results: As of December 7, 2019, 82 anti–CTLA-4 naive pts with various adv cancers received BMS-986249 ± NIVO (mono, n = 39; combo, n = 43). Median age 60 (25–78) y; 95% pts had prior systemic therapy. TRAEs occurred in 59% of pts (Gr 3/4, 23%) with mono and 74% of pts (Gr 3/4, 30%) with combo. Diarrhea was the most common any-Gr TRAE (mono, 23%; combo, 21%) and Gr 3/4 TRAE (mono, 15%; combo, 7%). Rates of Gr 3/4 TRAEs increased with higher doses of BMS-986249 but were substantially reduced with Q8W schedule (eg, 800 mg Q4W, 18%; 1600 mg Q4W, 60%; 1600 mg Q8W, 9%). Most TRAEs resolved, no Gr 5 TRAEs occurred. The peptide-masked intact probody accounted for most (73%) of the systemic BMS-986249-related species; elimination of the probody indicated involvement of both catabolism and cleavage processes. Conclusions: BMS-986249 ± NIVO displayed a clinically manageable safety profile, allowing assessment of comparably higher BMS-986249 dose intensity (240-1200 mg; ≈ 3-15 mg/kg) + NIVO (480 mg Q4W, full dose) than that tested with IPI + NIVO. The types of TRAEs were consistent with CTLA-4 blockade, and the overall data align with the proposed Pb-Tx mechanism of action. The preclinical and clinical data support the ongoing randomized BMS-986249 + NIVO expansion in pts with adv melanoma, in addition to other adv tumors. Clinical trial information: NCT03369223 .
A first-in-human phase I study in patients with advanced and/or refractory solid malignancies to evaluate the safety of ATOR-1015, a CTLA-4 x OX40 bispecific antibody.
Authors: Yachnin Jeffrey , Ullenhag Gustav J. , Carneiro Ana , Nielsen Dorte , Rohrberg Kristoffer Staal , Kvarnhammar Anne Månsson , Schultz Lena , Bågeman Erika , Wennersten Camilla , Russell Charlotte Astrid 
Published: May 2020

3061 Background: ATOR-1015 is a human CTLA-4 x OX40 targeting IgG1 bispecific antibody developed to be a next generation CTLA-4 antibody with enhanced immune activation and tumor-directed activity for improved efficacy and reduced toxicity. Methods: The primary objective of the study is to determine the maximum tolerated dose (MTD) and/or the recommended phase 2 dose (RP2D) in patients with advanced solid malignancies. Safety and tolerability of ATOR-1015 are assessed by adverse events (AEs), vital signs, ECG, laboratory evaluations and physical examinations. Secondary objectives include pharmacokinetics (PK), immunogenicity and clinical efficacy. Clinical efficacy is assessed using Response Evaluation Criteria in Solid Tumors for immune-based therapeutics (iRECIST). The study is designed with single patient cohorts for doses below 100 mg followed by a modified 3+3 design (NCT03782467). Intra-patient dose escalation is allowed. ATOR-1015 is administered intravenously every other week as a single agent until confirmed progressive disease, unacceptable toxicity or withdrawal of consent. Results: From March 2019 to February 2020, 15 patients have been exposed to ATOR-1015. The median age of the patients is 52 years (range 40-72). The following cancer types have been included: colorectal cancer (n=8), uveal melanoma (n=2), pancreatic cancer (n=2), ovarian cancer (n=2), and cholangiocarcinoma (n=1). Patients received a median of 6 prior lines of therapy (range 3-16). Dose levels from 0.043 mg to 200 mg have been evaluated and declared safe. Dose escalation is ongoing, and 400 mg is under evaluation. The median time on study was 8 weeks (range 2.1-34.3). Four patients are on study and eleven patients have discontinued treatment . Reasons for discontinuation include clinical deterioration (n=7), death due to disease progression (n=2), confirmed disease progression (n=1) and investigator´s decision (n=1). Six of the 15 patients experienced drug-related AEs which were grade 2 or less. Infusion-related reactions (IRR) were reported in four patients. One of those four also had abdominal pain and mediastinal burning sensation. The IRR symptoms were predominantly rash. One patient had vitiligo, and one had rash. No dose-limiting toxicities have occurred. Preliminary PK data show dose-proportional kinetics up to 200 mg. Conclusions: The dosing of ATOR-1015 has been safe and well-tolerated up to 200 mg. Dose escalation continues and the current dose level under evaluation is 400 mg. Clinical trial information: NCT03782467 .
Statin treatment improves response to anti-PD1 agents in patients with malignant pleural mesothelioma and non-small cell lung cancer.
Authors: Cantini Luca , Pecci Federica , Hurkmans Daan , Copparoni Cecilia , Aerts Sophie , Belderbos Robert A , Cornelissen Robin , Dumoulin Daphne P , Fiordoliva Ilaria , Rinaldi Silvia , Aerts Joachim , Berardi Rossana 
Published: May 2020

3074 Background: After progression to standard chemotherapy, only a small proportion of malignant pleural mesothelioma (MPM) and non-small cell lung cancer (NSCLC) patients (pts) benefit from anti-programmed cell death (PD-1) treatment. Combination strategies might improve response. In pre-clinical models, statins showed vaccine adjuvant activities and synergized with anti-PD1 agents. In this multi-center study, we evaluated the impact of baseline statin treatment in MPM and NSCLC pts. Methods: We separately examined MPM and NSCLC pts treated with anti-PD1 monotherapy after progression to standard chemotherapy at two European academic institutions. As control cohort, MPM pts treated with first-line chemotherapy were also examined. Pts receiving statins at start of treatment were compared with those who did not. Objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were analyzed. Results: A total of 287 patients were examined. Twenty-seven out of 80 (34%) MPM and 36 out of 130 (20%) NSCLC pts received statins at start of anti-PD1 treatment. The most common statins were simvastatin, atorvastatin and rosuvastatin. In MPM pts, statin use was associated with improved ORR (22% versus 5%, P = 0.05), longer PFS (median 6.7 versus 2.4 months, hazard ratio (HR) 0.42, 95% confidence interval (CI) 0.23–0.77, P < 0.01), and longer OS (median not reached versus 6.0 months, HR 0.43, 95% CI 0.21–0.85, P = 0.01). In NSCLC pts, statin use was associated with improved ORR (40% versus 22%, P = 0.04), longer PFS (median 7.8 versus 3.6 months, HR 0.59, 95% CI 0.37–0.97.2, P = 0.03) but similar OS (median 13.1 versus 10.1 months, HR 0.79, 95% CI 0.49–1.28, P = 0.30). At multivariate analyses, after adjusting for ECOG performance status (PS) and histological subtype, the impact of statins remained significant for ORR, PFS and OS in MPM and for PFS in NSCLC. Conversely, no association between statin use and outcomes was found in 77 MPM pts treated with first-line chemotherapy. Conclusions: This study shows that statin use at start of anti-PD1 treatment improves response to anti-PD1 agents in MPM and NSCLC pts who progressed to standard chemotherapy in routine clinical practice. This association could not be found in MPM pts treated with first-line chemotherapy, thus suggesting a synergy between statins and anti-PD1 agents. Prospective studies are needed to confirm whether the combination of statin and anti-PD1 therapy could improve outcome in pts with poorly immunogenic thoracic malignancies.
Novel blood-based biomarker predicting severe toxicity in melanoma anti-CTLA-4 immunotherapy treatment.
Authors: Chat Vylyny , Ferguson Robert , Morales Leah , Monson Kelsey , Esteva Eduardo , Moran Una , Pavlick Anna C. , Ascierto Paolo Antonio , Osman Iman , Weber Jeffrey S. , Kirchhoff Tomas 
Published: May 2020

3077 Background: Immune checkpoint inhibition (ICI) has improved clinical outcomes of metastatic melanoma (MM). However, 65-80% of treated patients experience immune-related adverse events (irAEs), urging for the availability of personalized and easy-access clinical biomarkers. We have previously shown that germline genetics related to host immunity affects ICI response and MM survival. In this study, we investigated if germline immune-related expression quantitative trait loci (ieQTLs) may predict ICI-induced irAEs in MM. Methods: Through a comprehensive interrogation of a healthy twin-cohort expression dataset (MuTHER), we identified 40 ieQTLs most significantly associated with the expression of 382 immune-related genes. These germline variants were genotyped using the MassARRAY system in anti-CTLA-4-treated MM patients, collected as part of a multi-institutional collaboration. Using multivariable logistic regression models, we tested the association of 40 ieQTLs with irAEs in a discovery cohort of 97 MM patients followed by a validation in additional cohort of 97 anti-CTLA-4 treated patients. Results: We found rs7036417 significantly associated with severe anti-CTLA-4 irAEs in the discovery (OR = 6.18; 95%CI = 1.61-23.74; p = 0.007) and validation (OR = 6.73, 95%CI = 1.42-31.86; p = 0.02) cohorts. Pooled analysis showed that carriers of two rs7036417 alternate alleles (TT) have a 6-fold increased risk of developing severe irAEs (OR = 6.11; 95% = 2.26-16.56;p = 0.0003). This association was not observed with ICI response or survival. The alternate allele of rs7036417 is associated with higher expression of SYK (spleen-associated tyrosine kinase), suggesting that elevated SYK contributes to developing severe irAEs. Conclusions: We report that rs7036417, an ieQTL in SYK, associates with an increased risk of severe irAEs, independent of ICI efficacy. SYK plays an important role in B-cell/T-cell expansion and increased pSYK has been reported in patients with rheumatoid arthritis or systemic lupus erythematosus. Based on our data, the over-expression of SYK likely explains the biological mechanisms of the association between rs7036417 and anti-CTLA4 irAEs. These findings propose a novel blood-based baseline biomarker stratifying the patients at increased risk of severe irAEs, with a clinical effect substantially surpassing those observed for currently available predictors. Our ongoing studies are currently investigating SYK eQTL as a novel target in toxicity-reducing therapies.
Prevalence of human leukocyte antigen-B27 supertype in the context of positively charged neoepitopes and association with PD-L1 as an immune escape mechanism.
Authors: Fares Charlene Marie , Cummings Amy Lauren , Theisen Matthew Karl , Gukasyan Jaklin , Lind-Lebuffe Jackson P , Akingbemi Wisdom O , Li Debory Y , Brodrick Paige M , Yessuf Nawal M , Barksdale Chantal Ava , Wong Deborah J.L. , Lisberg Aaron Elliott , Garon Edward B. 
Published: May 2020

3083 Background: Recent evidence suggests efficacy of immune checkpoint blockade may be influenced by human leukocyte antigen (HLA)-B. HLA-B27 supertype has an electronegative binding pocket which favorably binds and displays neoepitopes harboring positively charged amino acids (AAs). Based on immune surveillance, we postulate that B27 tumors that have favorable neoepitopes should face negative selective pressure, and B27 tumors with favorable neoepitopes that develop could be more likely to upregulate immune escape mechanisms. Here we evaluate the relationship between prevalence of B27 and positively charged neoepitopes and assess association between positively charged neoepitopes and expression of PD-L1. Methods: TCGA datasets from head and neck squamous cell (HNSC), lung squamous cell (LUSC), and melanoma (SKCM) patients were evaluated. HLA alleles were determined with OptiType and supertype was based on 2008 criteria. Nonsynonymous mutations were annotated with Ensembl VEP and VAtools. pVAC-Seq using NetMHCpan algorithm predicted neoepitopes 9 AAs in length. Favorable B27 neoepitopes were defined as those having new positively charged AA substitutions (H/K/R) from negative or uncharged wildtype AAs. RNA-seq data for the PD-L1 gene were normalized on transcripts per million and log2 transformed. Linear regression tests were performed between PD-L1 gene expression values and fraction of nonsynonymous mutations resulting in neoepitopes with new positively charged AAs in patients with B27. Results: Data from 497 HNSC, 494 LUSC, and 468 SKCM patients were analyzed. B27 was observed in 20.1%, 23.2%, and 26.5% of HNSC, LUSC, and SKCM patients, respectively, with a significant difference seen between HNSC and SKCM by chi-square test (χ² = 5.14, p = .023). Of new charged AAs resulting from nonsynonymous mutations, 76.3% in HNSC, 74.0% in LUSC, and 72.0% in SKCM were positively charged (p < .05 between all histologies, paired t-tests). In B27 patients, association between PD-L1 gene expression and fraction of neoepitopes with new positively charged AAs was seen in HNSC (r = 0.25 p = .036) and SKCM (r = 0.30 p = .007), but not LUSC (r = -0.12 p = .296). Conclusions: With increasing fraction of positively charged neoepitopes, a decrease in prevalence of B27 was observed, suggesting improved binding and immune elimination of tumors with favorable neoepitopes. In B27 tumors that develop despite having favorable neoepitopes, upregulation of PD-L1 could be a putative mechanism to evade immune detection.
Effect of Kaiso on immune signaling of breast cancer exosomes.
Authors: Dean-Colomb Windy Marie , Ahmed Shakir , Karanam Balasubramanyanam , Wang Honghe , Davis Melissa , Grizzle William E. , Gardner Kevin , Yates Clayton 
Published: May 2020

3088 Background: Exosomes are communication vesicles that act as mediators of intracellular transfer of genetic information, an important role in intercommunication between tumor cells and immune cells. However, the mechanism underlining this cell-cell communication is not well understanding, particularly in African American breast cancer patients. Recently, our lab has demonstrated that Kaiso, a novel bi-modal transcription factor is highly expressed in African American breast cancer and notably, high Kaiso expression correlates with breast cancer aggressiveness and the disparity in survival outcomes of breast cancer patients of African American compared to European American patients. However, the differential expression and biological consequences of Kaiso in immune signaling of breast cancer exosomes has not been studied yet. Herein we demonstrate the biological role of Kaiso in immune signaling in breast cancer exosomes. Methods: In this study we utilized Nanostring immune profiling technology along with multiple in vitro and in vivo assays were used to study the role of Kaiso in breast cancer immune escape. Results: Nanostring pan cancer immune profiling demonstrated that European American breast cancer exosomes exhibited higher expression of TILs markers, T cell activation markers and CD8+T Cells markers compared to African American (p < 0.05, FDR), while we observed an increase in the expression of the anti-phagocytic molecule CD47 in breast cancer patient exosomes of African American compared to European American patients. In addition to that CD47 and SIRP-α (Signal Regulatory Protein) are highly expressed in Kaiso-scrambled MDA-MB-231 cells (sh-Scr) and exosomes, whereas THBS1, which is a regulator of CD47 expression and is regarded as angiogenesis inhibitor is significantly increased in sh-Kaiso MDA-231 cells and exosomes. Additionally, we observed that Kaiso directly binds methylated sequences in the promoter region of CD47 and THBS1 by ChIP assay. Furthermore, in vivo sh-Kaiso cells injected into athymic mice exhibited delayed tumor formation after four weeks with smaller tumor size as compared to sh-SCR cells (p < 0.05), and we observed higher expression of THBS1 with lower expression of CD47 and SIRP-α molecules by IHC and exosomes isolated from in vivo tumors (p < 0.05), indicating that Kaiso is associated with macrophage mediated immune escape. Conclusions: These findings demonstrate the important role of kaiso in immune signaling through exosomes which may be related with more aggressive cancer phenotype in breast cancer, especially in African Americans.
Single vector multiplexed shRNA provides a non-gene edited strategy to concurrently knockdown the expression of multiple genes in CAR T cells.
Authors: Gilham David Edward , Bornschein Simon , Springuel Lorraine , Michaux Alexandre , Steklov Mikhail , Breman Eytan , Sotiropoulou Panagiota A 
Published: May 2020

3103 Background: Engineered T cells expressing chimeric antigen receptors (CAR) are now delivering clinically relevant results in patients with advanced hematological malignancies. One critical area for future development is to modulate gene expression thereby endowing the engineered T cell with specific desired features that enhance anti-tumor activity. Methods: Short-hairpin RNA (shRNA) were cloned individually or multiplexed within micro-RNA scaffolds that enabled the co-expression of the individual shRNA with a CAR and a selectable marker all driven by a PolII promoter within a single retroviral vector. Primary human T cells transduced with the CAR-shRNA vectors were selected, expanded in vitro, subjected to negative selection to eliminate any remaining TCR+ cells and examined for target gene expression and functional activity. Results: A 500bp DNA fragment incorporating a shRNA-specific for CD3ζ cloned into a retroviral vectoreffectively knocked down expression of CD3ζ in transduced BCMA-specific CAR T cells. The consequent reduction of cell surface TCR expression resulted in minimal cytokine production upon TCR stimulation in vitro providing a potential allogeneic CAR T approach. These CAR T cells showed no demonstrable evidence of GvHD induction when infused in NSG mice yet maintained BCMA-specific CAR activity in KMS-11 and RPMI-8226 established myeloma models. Initial studies further confirmed that two shRNA could be expressed from a single retroviral vector to modulate the expression of multiple genes. Further engineering of the microRNA framework reduced the size of the transgene load to 394bp while enabling the expression of up to 4 shRNA within a single vector. shRNA specific for CD3ζ, beta-2-microglobulin, CD52 and diacylglycerol kinase alpha were engineered into the framework downstream of a CD19-CAR. Transduced Jurkat cells showed concurrent knockdown of the respective gene products at the mRNA and protein levels. Conclusions: A first-in-human clinical trial evaluating the first-generation single shRNA-vector in the context of a BCMA-targeting CAR as a non-gene edited approach to allogeneic CAR T cell therapy will be initiated in 2020. The proof of principle study here shows that multiple shRNAs are active within a single viral vector thereby avoiding the need for bespoke individual clinical reagents to target multiple genes. The multiplexed shRNA vector system is now in further development to explore whether this strategy can enhance the therapeutic potential of CAR T cells.