bluuebunny/crossref_metadata_2025_split huggingface dataset:
Awareness and understanding of cancer immunotherapy in Europe.
Authors: Mellstedt Hakan , Gaudernack Gustav , Gerritsen Winald R. , Huber Christoph , Melero Ignacio , Parmiani Giorgio , Scholl Suzy , Thatcher Nick , Wagstaff John , Zielinski Christoph 
Published: March 2020

3053 Background: Use of immunotherapies in the treatment of cancer is growing and a range of new immunotherapeutic strategies are being evaluated. It is important that healthcare providers (HCP) understand these treatments and how they compare with and may complement established therapies. As part of the activities of the POINT expert group, we commissioned a survey of current awareness, attitudes and perceptions of cancer immunotherapy in Europe. Methods: From August-September 2011, 426 healthcare professionals (HCPs: oncologists, surgeons and oncology nurses) from France, Germany, Italy, Spain and the UK (~85 respondents/country) completed online interviews. Representatives of patient advocacy groups (PAGs) in each country were surveyed by telephone interview. Results: Nearly all (98%) HCPs were aware of cancer immunotherapy. While 68% of HCPs indicated a high level of interest, knowledge levels were lower. Only 24% of the HCPs had direct experience with cancer immunotherapies, while others reported they knew a lot (12%), a reasonable amount (28%) or little (34%) about immunotherapy strategies but had not used them (76%). Overall perceptions of cancer immunotherapy among HCPs were largely positive (60%) and rarely negative (3%). The key advantages of cancer immunotherapy were perceived to be good safety and tolerability (75%), a targeted mechanism of action (61%) and good efficacy (48%). The leading barriers to use of immunotherapies were costs of treatment (58%), past clinical trial failures (45%) and access/formulary restrictions (44%). Most (75%) HCPs had already discussed cancer immunotherapy with their patients and 70% of patients were reported as being receptive to the concept. The majority of PAGs indicated they were currently unable to advise patients about cancer immunotherapy due to a lack of or confusing information and poor understanding. Conclusions: Awareness of cancer immunotherapy in Europe is high and it is generally perceived as a positive addition to established treatment options. However, the understanding varies and the direct experience is limited. There is a clear need for further educational activities concerning cancer immunotherapy, as well as further clinical data on long-term efficacy and safety.
Antitumor activity of concurrent blockade of immune checkpoint molecules CTLA-4 and PD-1 in preclinical models.
Authors: Selby Mark , Engelhardt John , Lu Li-Sheng , Quigley Michael , Wang Changyu , Chen Bingliang , Korman Alan J. 
Published: March 2020

3061 Background: Interaction of immune checkpoint molecules PD-1 and CTLA-4 and their respective ligands attenuates antitumor T cell responses. In clinical studies, PD-1 blocking antibody (Ab) nivolumab (BMS-936558) or the CTLA-4 blocking Ab ipilimumab result in durable responses in multiple human malignancies. We describe the evaluation of concurrent treatment with anti-PD-1 and anti-CTLA-4 mAbs in preclinical models. Methods: Antitumor activity of treatment with murine homologs of anti-PD-1 (4H2-mIgG1) and anti-CTLA-4 (9D9-mIgG2b) was evaluated in MC38, a murine colon adenocarcinoma model. The effects of concurrent treatment on T cell infiltration of tumors, tumoral expression of PD-L1 and cytokine levels were explored. The preclinical safety profile of concurrent nivolumab + ipilimumab was assessed in a cynomolgus macaque model. Results: Concurrent treatment of MC38 tumors with 4H2-mIgG1 + 9D9-mIgG2b (10 mg/kg Q3d x 3) results in synergistic antitumor activity whereas efficacy with sequential dosing was similar to either agent alone. With concurrent treatment, dose reductions of one Ab relative to a fixed dose of the other resulted in retention of some antitumor activity. Anti-PD-1 enhanced CD8+ T cell infiltration of MC38 tumors and increased tumor PD-L1 expression. Anti-CTLA-4 treatment increased intratumoral CD8+ T cells and reduced intratumoral T regulatory cells. While concurrent treatment did not result in further increases in T cell infiltration, it increased expression of intratumoral cytokines. Anti-PD-1 resulted in down regulation of cell surface and intracellular levels of PD-1 in CD8+ T cells. In cynomolgus macaques, concurrent nivolumab + ipilimumab resulted in dose-dependent gastrointestinal toxicities (diarrhea; body weight loss) not observed in earlier cynomolgus studies with nivolumab and rarely with ipilimumab. These preclinical observations provided the rationale for a dose escalation trial (NCT01024231) of combined nivolumab + ipilimumab in advanced melanoma. Conclusions: Concurrent treatment with anti-PD-1/anti-CTLA-4 resulted in synergistic antitumor activity in preclinical models and supports the evaluation of the combination in clinical studies.
Use of an antibody-drug conjugate targeting tissue factor to induce complete tumor regression in xenograft models with heterogeneous target expression.
Authors: Breij Esther CW , Satijn David , Verploegen Sandra , de Goeij Bart , Schuurhuis Danita , Bleeker Wim , Houtkamp Mischa , Parren Paul 
Published: March 2020

3066 Background: Tissue factor (TF) is the main initiator of coagulation, that starts when circulating factor VII(a) (FVII(a)) binds membrane bound TF. In addition, the TF:FVIIa complex can initiate a pro-angiogenic signaling pathway by activation of PAR-2. TF is aberrantly expressed in many solid tumors, and expression has been associated with poor prognosis. TF-011-vcMMAE, an antibody-drug conjugate (ADC) under development for the treatment of solid tumors, is composed of a human TF specific antibody (TF-011), a proteaseEcleavable valine-citrulline (vc) linker and the microtubule disrupting agent monomethyl auristatin E (MMAE). Methods: TF-011 and TF-011-vcMMAE were functionally characterized using in vitro assays. In vivo anti-tumor activity of TF-011-vcMMAE was assessed in human biopsy derived xenograft models, which genetically and histologically resemble human tumors. TF expression in xenografts was assessed using immunohistochemistry. Results: TF-011 inhibited TF:FVIIa induced intracellular signaling and efficiently killed tumor cells by antibody dependent cell-mediated cytoxicity in vitro, but showed only minor inhibition of TF procoagulant activity. TF-011 was rapidly internalized and targeted to the lysosomes, a prerequisite for intracellular MMAE release and subsequent tumor cell killing by the ADC. Indeed, TF-011-vcMMAE efficiently and specifically killed TF-positive tumors in vitro and in vivo. Importantly, TF-011-vcMMAE showed excellent anti-tumor activity in human biopsyEderived xenograft models derived from bladder, lung, pancreas, prostate, ovarian and cervical cancer (n=7). TF expression in these models was heterogeneous, ranging from 25-100% of tumor cells. Complete tumor regression was observed in all models, including cervical and ovarian cancer xenografts that showed only 25-50% TF positive tumor cells. Conclusions: TF-011-vcMMAE is a promising new ADC with potent anti-tumor activity in xenograft models that represent the heterogeneity of human tumors, including heterogeneous TF expression. The functional characteristics of TF-011-vcMMAE allow efficient tumor targeting, with minimal impact on coagulation.
Novel heteroclitic XBP1 peptides evoking antigen-specific cytotoxic T lymphocytes targeting various solid tumors.
Authors: Bae Jooeun , Carrasco Ruben , Daley John , Dranoff Glen , Anderson Kenneth Carl , Munshi Nikhil C. 
Published: March 2020

3067 Background: Activation of the unfolded protein response (UPR) allows for tumor cells to survive prolonged endoplasmic reticulum stress and hypoxic conditions. XBP1 is an upstream element and a critical transcriptional activator of the UPR, and its up-regulation in a variety of human solid tumor cancers makes it as a promising immunotherapeutic target. The purpose of these studies was to evaluate immunogenic HLA-A2 XBP1-specific peptides for their ability to elicit cytotoxic T lymphocytes (CTL) against a variety of solid tumor cell lines. Methods: Upon the validation of XBP1 peptides for their strong HLA-A2 bindings and stabilities, peptide-specific CTL were generated ex vivo by repeated stimulation of CD3+ T lymphocytes obtained from HLA-A2+normal donors with XBP1 peptides-pulsed antigen-presenting cells, either dendritic cells or T2 cells. Results: A cocktail of heteroclitic XBP1 US184-192 (YISPWILAV) and heteroclitic XBP1 SP367-375 (YLFPQLISV) peptides with significantly improved HLA-A2 affinity and stability from their native counterparts were used to evoke XBP1 antigen-specific CTL. The CTL were predominantly CD3+CD8+ T cells (>80%) containing a high percentage of Effector Memory (EM; CCR7-CD45RO+) cells, which were distinctively evoked by repeated stimulation with the XBP1 peptides. In addition, the XBP1-CTL displayed a high level of cellular activation (CD69+/CD3+CD8+). The XBP1-CTL demonstrated effective anti-tumor responses including cell proliferation and IFN-g production, as well as degranulation (cytotoxic activity) against HLA-A2+breast cancer (MB231, MCF7), colon cancer (LS180, SW480) and pancreatic cancer (8902, Panc1, PL45) cell lines, which over-express both unspliced and spliced XBP1 antigens. Importantly, the specific anti-tumor activities were detected primarily in the EM CTL subset. Conclusions: These results suggest the immunotherapeutic potential of a cocktail of heteroclitic XBP1 US184-192 and XBP1 SP367-375 peptides to elicit effective anti-tumor responses against various solid tumors, and provide the framework for clinical development of vaccine trials to improve patient outcome.
Anti-60S ribosomal protein L29 antibody: New anticancer agent discovered from human sera.
Authors: Miyake Yasuhiro , Matsushita Hiroshi , Yamamoto Kazuhide 
Published: March 2020

3071 Background: Incidence of hepatocellular carcinoma (HCC) is lower in autoimmune hepatitis (AIH) than chronic viral hepatitis. In AIH, serum immunoglobulin G (IgG) levels are associated with the clinical features. In this study, we searched IgG showing anti-tumor effect in sera of AIH patients. Methods: Total IgG was extracted from sera of AIH patients by using protein G. Anti-tumor effects of the total IgG were evaluated by MTT assay using human HCC Huh7 cells and PLC/PRF/5 cells. Autoantigens in membrane proteins of Huh7 cells were screened by immunoprecipitation followed by liquid chromatography-mass spectrometry (LC-MS) shotgun analysis. Results: In one AIH patient without any cancers, addition of total IgG extracted from her serum to the culture inhibited the proliferation of Huh7 cells and PLC/PRF/5 cells, and decreased intracellular levels of β-Catenin and Cyclin-D1. In this patient, autoantigens in membrane proteins were screened, and 60S ribosomal protein L29 (RPL29) was identified from the MS/MS spectra and the SwissProt database using the Mascot Search engine. RPL29 expression in human HCC cell lines including Huh7, PLC/PRF/5, Hep3B, HepG2, HLE, HLF and SK-Hep-1 were identified by Western blot. Next, in the other 25 AIH patients, we investigated the correlation between serum anti-RPL29 levels by indirect ELISA using recombinant RPL29 and anti-tumor effects of total IgG extracted from their sera. Serum anti-RPL29 levels were significantly correlated with anti-tumor effects of total IgG extracted from their sera (P <0.0001). On the other hand, addition of recombinant RPL29 to the culture canceled anti-tumor effects of total IgG extracted from sera of AIH patients showing higher serum anti-RPL29 levels. Additionally, these anti-tumor effects of total IgG extracted from sera of AIH patients were shown by MTT assay using human pancreatic cancer AsPC-1 cells and Panc-1 cells. Conclusions: Anti-RPL29 antibodies showing anti-tumor effect were discovered from human sera. Anti-RPL29 inhibits cancer cell proliferation via down-regulation of Wnt/β-Catenin signaling pathway. Serum anti-RPL29 may be one of immune systems by which the human does not develop cancers.
Novel murine anti-HER2 monoclonal antibodies to induce apoptosis and regulate miR-21 in breast cancer cell.
Authors: Kim Alice Y. , Zer Cindy , Williams John C. , Press Michael F. , Park Jinha Mark 
Published: March 2020

3081 Background: MicroRNAs play critical roles in biological and pathological processes. Of these, miR-21 is frequently observed to be overexpressed in various cancers. However, treatment of breast cancer cells with trastuzumab enhances the level of miR-21 by a relative fold of 2.26 (Ichikawa, PLos ONE, 2012, p.5). In this study, we demonstrate that two murine anti-HER2 mAbs, 10H8 and 8H11, while inhibiting cell proliferation and inducing apoptosis, do not perturb the level of miR-21 in the same way as trastuzumab. To understand the differential effects of trastuzmab and the two mAbs, epitope mapping studies were also conducted. Methods: SKBR3 cells were used to confirm HER2 binding and determine the antibodies’ impact on proliferation, apoptosis, and miRNA expression. Cell proliferation upon a 3-day antibody treatment (10 to 15 μg/ml) was measured using MTS and Crystal Violet Assays. Apoptotic cells were identified using Annexin V-FITC flow cytometry. To determine their epitope mapping, cells were grown on coverslips overnight, fixed, blocked, and incubated in AF488-mAb or AF555-mAb, and images were captured with IX81. QRT-PCR was used to measure the relative levels of miR-21, using miR-16 as the endogenous control Results: Cell proliferation assays showed that the treatment of 10H8 resulted in a better growth inhibition in SKBr3 cells than that of trastuzumab (ex: 80.2% vs 84%, respectively). Combining 10H8 and 8H11 produced less viable cells and more early- and post-apoptotic cells than those treated with trastuzumab alone. In addition, whereas trastuzumab increased the relative quantity of the known oncogene, both 10H8 and 8H11 maintained a steady level of miR-21 (0.99 and 1.2, respectively). Conclusions: Initial results indicate that 10H8 and 8H11 inhibit cell proliferation and induce apoptosis in HER2-overexpressing cells. However, unlike trastuzumab, 10H8 and 8H11 do not involve miR-21 up-regulation. Moreover, the three mAbs do not have overlapping epitopes on HER2. Further investigations of the antibodies’ impact on intracellular signaling pathways and the structural determination of the HER2 binding sites would provide further understanding of the therapeutic potentials of these two mAbs.
NfP2X7, a novel target for immune therapeutic approaches in cancer treatment.
Authors: Nesselhut Jan , Barden Julian , Marx Dagmar , Cillien Nicole , Goebel Wiebke , Herrmann Michael , Chang Raymond Y. , Nesselhut Thomas 
Published: March 2020

3094 Background: P2X7 receptor, a ligand-gated channel, is activated by extracellular ATP and mediates ATP induced apoptosis. Several polymorphisms leading to loss of function of P2X7 have been described. Overexpression of non-functioning P2X7 receptor (nfP2X7), able to form a Ca2+channel but not an apoptotic pore, is found on every type of cancer cell but no normal cells, making it a perfectly selective target for immune therapy approaches. Methods: Samples from various tumor types were analyzed for the expression of nfP2X7 using immunohistochemistry. MoDC from n=6 patients with advanced metastatic sarcoma (2 osteosarcoma, 4 soft tissue sarcoma) with disease progression after failure of extensive standard therapies were primed against the nfP2X7using a specific peptide. MoDC were harvested, analyzed by flow cytometry and applied to the patient intradermaly. Specific T-cell response was analyzed by IFN-gamma Elispot. Results: nfP2X7 is overexpressed in essentially all analyzed tumor samples from all cell types: epithelial, mesenchymal, neural, germinal examined in large numbers (n = 5 to >1,000). The uniquely displayed epitope associated with the ATP binding site exposed on nfP2X7 but hidden in P2X7 was found on the cancer cell surface but not on the surface of any normal cells. MoDC primed with a specific peptide against nfP2X7 show a distinct DC morphology and an up-regulation of the maturation marker CD83. Patients are 6-9 months (onset June 2012) under treatment at time of abstract submission. 2 patients have a disease stabilization. One further patient with a metastatic, rapidly growing osteosarcoma showed a mixed response. IFN-gamma Elispot, which was exemplarily performed, shows a nfP2X7-specific T-cell response. Conclusions: Efficient inductions of an antitumor response by dendritic cell therapy require the definition and choice of an optimal target, being expressed in almost all kinds of tumors. nfP2X7, a set of non-functioning forms of the P2X7 receptor unable to initiate apoptosis but maintaining channel activity, could therefore be an optimal universal candidate. The efficacy of dendritic-cell based therapy may be improved by priming the MoDC against nfP2X7 and thus may improve the clinical outcome.
Risk factors for development of delayed urticarial reactions in the phase II trial of HER2 peptide vaccines plus GM-CSF versus GM-CSF alone in high-risk breast cancer patients to prevent recurrence.
Authors: Trappey Alfred F , Berry John S. , Vreeland Timothy J , Hale Diane F. , Sears Alan K. , Ponniah Sathibalan , Perez Sonia A. , Clifton Guy T. , Papamichail Michael , Shumway Nathan M. , Mittendorf Elizabeth Ann , Peoples George Earl 
Published: March 2020

3097 Background: We are monitoring the incidence of delayed urticarial reactions (DURs) in our phase II trial evaluating adjuvant HER2-specific vaccines (AE37 and GP2) for the prevention of breast cancer recurrence. Here, we characterize DURs and analyze risk factors for their development. Methods: After completion of standard of care therapy, disease-free node-positive or high-risk node-negative patients (pts) were randomized to receive either a peptide+GM-CSF (VG) or GM-CSF (CG). Pts receive 6 monthly intradermal inoculations during the primary vaccine series (PVS) then four boosters (B) every 6 mos. Immune response is measured by delayed type hypersensitivity (DTH) pre- (R0) and post-PVS (R6) and local reaction (LR) at R1 – R6. Results: Twenty-four (6.1%) of 393 initiated patients report a DUR; 13 VG (vDUR), and 11 CG (cDUR); vDUR - 9 AE37, 4 GP2. Time to onset of symptoms is 9±5 days (d) and is similar in vDUR/cDUR (p = 0.27). DURs manifest as hives/pruritis in all patients. Average duration of symptoms is 32.6 d ± 8.8 d (no difference in vDUR/cDUR [p = 0.23]). Episodes have resolved with antihistamines or IV/oral steroids. Ten (4 cDUR, 6 vDUR) patients have had recurrent episodes that have resolved similarly. 75% of first episodes occur between R6-B3. For DUR patients v. those who have not had a DUR (noDUR), there are no differences in demographics. DTH response is similar in vDUR pts v. noDUR VG pts (R0- p = 0.34; R6- p=0.40). cDUR pts had a greater DTH response v. CG noDUR pts at R6 (13.2 v 4.7 mm, p=0.01). LRs are greater in DUR pts compared to noDUR pts after the second vaccination (R2 – 66.2 v 48.2 mm, p=0.02). LR for DUR pts decrease and are less than noDUR at R6 (45.4 v 57.4 mm, p=0.09). Relative risk for developing DUR for LR > 100 mm at R2 is 3.49 (1.58-7.68, 95% CI [p=0.004]). At 29.9 months median follow-up, there have been no recurrences in VG and CG DUR v. 75.9% DFS for noDUR (p=0.05). Conclusions: DURs occur infrequently and without long-term sequelae. Pts at risk for developing DUR are identified early in the vaccine series using LR. Robust immune response in DUR may explain the survival benefit demonstrated here. Clinical trial information: NCT00524277.
Economic analysis of pharmacokinetic (PK) studies in phase I clinical trials.
Authors: El Osta Badi Edmond , Falchook Gerald Steven , Schaub Diane , Subramanian Harihara , Daneshmand Maryam , Harleaux Dina , Karp Daniel D. 
Published: March 2020

3103 Background: Although PK evaluation is a prevalent and critical component of cancer drug development, optimization of the cost-value relationship of PK studies has not been evaluated. Methods: We reviewed 26 phase I protocols that were activated and performed in the Clinical & Translational Research Center at U.T. MD Anderson Cancer Center from 2010 to 2012. 23 protocols met the residual analysis criteria of a normal and independent distribution. We collected protocol-specific data including medication, route, frequency, mechanism of action, number of enrolled patients, number of PK time points, and PK charges. Results: All 23 protocols were funded by industry sponsors. During 2010-2012: the total number of patients was 560; the median number of patients enrolled per protocol at our site was 18 (range 3-84); the median number of total PK studies per patient performed on each protocol was 19.46 (4.11-36.92); the median charge of PK time points was $42.33 (35.02-80.00); the median charge of all PK time points per patient on a protocol was $813.00 (329.00-1676.00); the median number of total PK studies per patient on a protocol during cycle 1 was 15.20 (2.40-27.47); the median charge of PK studies during cycle 1 was $43.24 (36.93-80). The number of PK time points and the amount of PK charges did not significantly correlate with monotherapy vs. combination regimens, oral vs. parenteral route, or small molecules vs. other (cytotoxic, vaccine, monoclonal antibodies). However, protocols (all cycles combined) with small molecules had a trend of lower PK time point median charges (41.97 vs. 52.67; p=0.09). Analysis of PKs in cycle 1 demonstrated that protocols with small molecules had a trend of higher PK time point median charges (61.33 vs. 42.38; p=0.08). Conclusions: The number and charges of PK studies was independent of the study drug or route. Future studies comparing budgeted vs. performed PKs and industry vs. investigator-initiated trials are warranted.