bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the trifunctional antibody catumaxomab (anti-EpCAM x anti-CD3) on proliferation and cytokine secretion of immune cells in malignant pleural effusion
Authors: Sebastian M. , Jaeger M. , Kiewe P. , Schuette W. , Wiewrodt R. , Lindhofer H. , Mueller B. , Friccius-Quecke H. , Friccius- Quecke H. , Schmittel A. 
Published: March 2020

3046 Background: The trifunctional antibody catumaxomab specifically binds EpCAM+ tumor cells, CD3+ T lymphocytes and accessory cells via FcγR I/III. Thus the antibody induces tumor specific cell mediated cytotoxicity in vitro and in vivo. Following last years’ ASCO presentation on a phase I/II trial showing safety and efficacy of repetitive intrapleural administration of catumaxomab in patients with EpCAM positive, malignant pleural effusion (MPE), we now present data on the responsiveness of immune cells from pleural fluid to catumaxomab. Methods: Pleural fluid of patients with EpCAM-positive MPE treated with i.pl. catumaxomab was collected before treatment. Cells were harvested from the fluid and cultured ± 100 ng/ml catumaxomab using an in vitro proliferation assay. After 72 h of culture, proliferation of T cells (CD4+ and CD8+) and monocytes (CD11c+) was determined. In addition, cell supernatants after 24h incubation ± catumaxomab were analysed for their TH1/TH2 cytokine profile (IL-2, IL-4, IL-6, IL-10, IFN-γ and TNF- a). Results: Incubation in presence of catumaxomab led to a pronounced increase of CD4+ CD8+ and CD11+ cell numbers indicating a proliferation of these cells, whereas cultures without catumaxomab showed no proliferation of immune cells. Analysis of supernatants after 24 h revealed levels of IL-2, IL-6, IFN-γ and TNF-a, from cells incubated with catumaxomab that were distinctly higher than in cultures without catumaxomab. Conclusions: The immunologic nature of catumaxomab-induced responses in patients with pleural effusion accompanied by a reduction of tumor cells, could be underlined impressively with in vitro data obtained from pleural cells showing catumaxomab-induced proliferation of T cells and accessory cells and TH1-directed cytokine secretion. The data are equivalent to results observed in the peritoneal fluid of ascites patients. [Table: see text]
Antibody-secreting cells to deliver antibody against brain metastases
Authors: Lampson L. A. , Tripp C. A. 
Published: March 2020

3047 Background: Antibody (AB) therapy has been successful against breast cancer, but brain mets are not well controlled. One likely factor is that AB molecules are too large to cross the blood-brain barrier (BBB). One approach is to truncate the AB, but this can affect its function. We propose an alternative. Unlike inert proteins, cells can cross the BBB. Indeed, antibody-secreting cells (ASC) are found in the brain in many neurologic disorders. Our hypothesis is that ASC, lodged within the brain, can be a source of AB to attack both pre-existing and new brain mets. We describe a new rat model to test this, and initial findings. Methods: Rat mammary carcinoma 13762 was made to constitutively express surrogate tumor antigens, either b-galactosidase (b-gal) or alkaline phosphatase (ap). Tumor cells were injected into the left common carotid artery of syngeneic CDF rats, to favor delivery to the brain. Tumor is identified by staining for keratin or the surrogate antigen. In a new assay, ASC are identified by a histochemical stain for their cognate antigen. As a positive control for ASC staining, spleens of immunized rats are used. Results: 1) The new histochemical assay does identify ASC correctly in positive and negative control spleens. 2) In the brains of rats that had been pre-immunized to b-gal, ASC specific for b-gal were seen at sites of b-gal+ tumor. 3) Some ASC were also seen away from tumor. Conclusions: Although ASC are known to enter the brain in many neurologic disorders, little work has stressed brain metastases. This new model allows study of ASC traffic to the brain in a tumor context. Favored sites of ASC entry and retention can be defined in both tumor-free brains (as appropriate for prophylaxis) and brains with pre-existing metastases. No significant financial relationships to disclose.
Anti-leukemia activity of CD33-specific chimeric cytotoxic T lymphocytes in vitro and in vivo is impaired by addition of the CD28 costimulatory endodomain
Authors: Dutour A. , Lee D. , Napier S. , Yvon E. , Finney H. , Brenner M. , Rousseau R. 
Published: March 2020

3052 Background: EBV-specific cytotoxic T cells (EBV-CTLs) expand and have long-term activity in vivo due to the sustained costimulation provided by the EBV-infected cells produced by this persistent virus. We exploited this phenomenon and redirected EBV-CTLs against CD33, a surface protein expressed on the malignant blasts of acute myeloid leukemia (AML) cells. Methods: EBV-CTLs generated from six EBV-seropositive donors were transduced using a retroviral vector encoding CD33 specific chimeric receptor (cR). We evaluated whether the high and sustained activity shown against native EBV+ target cells can be extended to the CD33+ EBV- targets of the chimeric receptor and whether the addition of CD28 signaling domain improved the receptor activity. Results: cRCD33-EBV-CTL maintained killed EBV-LCL and CD33+ targets (specific lysis respectively of 30% and 35% at E:T ratio 25:1). They produced Th-1, Th-2 and Tc cytokines on exposure to CD33+ targets. Addition of the CD28 intracellular domain did not increase cytotoxicity to CD33+ targets. Preincubation of CD33+ cells with the CD33-blocking MoAb resulted in up to 40% inhibition of lysis and up to 60% inhibition of cytokine release by cRCD33-EBV-CTLs confirming the specificity of the TCR interactions with CD33. NOD-SCID mice bearing a human CD33+ AML were injected with EBV-CTLs ×4 weekly starting 5 days after tumor inoculation. Significant tumor reduction was only observed in mice treated with the cRCD33-EBV-CTLs (p<0.05). Immunohistologic analysis showed the presence of a majority of CD8+ human T cells in the tumors of treated mice. Incorporation of the CD28 endodomain resulted in less tumor-infiltrating T cells in mice treated with cRCD33CD28-EBV-CTLs. There was no significant difference in the chemokines receptor expression on cRCD33CD28-EBV-CTLs but their rate of apoptosis was 16 % higher (p<0.05) than the one of cRCD33-EBV-CTLs. Conclusions: EBV- CTL expressing the CD33 chimeric receptor are functional in vitro and in vivo in mice. CD28 signaling may have a deleterious role for the activity of chimeric receptors in vivo. No significant financial relationships to disclose.
Depletion of Normal and Malignant B cells with a CD37-specific SMIP molecule
Authors: Cerveny C. , Grosmaire L. , Espling E. , Bader R. , Nilsson C. , Baum P. , Wahl A. , Ledbetter J. , Hayden-Ledbetter M. 
Published: March 2020

3063 Background: CD37 is a member of the tetraspanin family expressed at high levels by normal mature B cells and by most B cell malignancies. Previously, an antibody to CD37 has been labeled with 131I and tested in clinical trials for therapy of NHL. Treatment with 131I-MB-1, resulted in durable tumor remissions in patients lasting from 4 to 11 months (Press OW, Eary JF, Badger CC, et al. Treatment of refractory non-Hodgkin’s lymphoma with radiolabeled MB-1 (anti-CD37) antibody. J Clin Oncol. 1989;7:1027–1038). Here we assess the functional properties and therapeutic potential of a small modular immunopharmaceutical (SMIP) targeting CD37. Methods: Growth arrest and apoptosis of B lymphoma cell lines was assessed. ADCC activity was evaluated using BJAB targets and human peripheral blood mononuclear cells (PBMC) effectors. Drug-drug interactions were assessed by the Combination Index method. In vivo studies were performed utilizing established human B cell tumor xenografts in nude mice. Results: A CD37-directed SMIP drug candidate mediated growth arrest, apoptosis and ADCC, but not CDC, towards B lymphoma cell lines. The protein showed significant anti-tumor activity in a mouse xenograft model, and selectively depleted normal human B cells in short term cultures of PBMC. When combined with rituximab, the molecule increased apoptosis, C1q binding, and C’ dependent target cell death in vitro, and increased anti-tumor activity in vivo in a xenograft model. Conclusions: In vitro and in vivo characterization of the CD37-targeted SMIP drug suggest a potent capacity to eliminate target cells through combined effects of direct target cell signaling and effector cell recruitment. CD37-mediated growth was synergistic with standard chemotherapies in vitro and showed additive in vivo activity with CD20-targeted therapy. On the basis of these data CD37-directed SMIP therapy is being developed for clinical evaluation against B cell malignancies. No significant financial relationships to disclose.
Five-year overall survival (OS) in non-metastatic androgen-independent prostate cancer (AIPC) patients (pts) treated with nilutamide (N), vaccine (V), and combination therapy
Authors: Madan R. A. , Gulley J. L. , Dahut W. L. , Steinberg S. M. , Liewehr D. J. , Schlom J. , Arlen P. M. 
Published: March 2020

3066 Introduction: There is no standard treatment for pts with non-metastatic AIPC (D0.5).We previously performed the first randomized study in this pt population involving N,V, and combination therapy. To our knowledge this report is the first prospective analysis of OS data in pts with stage D0.5 AIPC. Methods: The initial study randomized 21 pts to treatment with N and 21 pts to treatment with V. The V was an admixture containing a vaccinia vector with the gene for PSA combined with vaccinia containing the costimulatory molecule B7.1. As part of this V strategy, pts also received monthly boosts of fowlpox-PSA with GM-CSF and IL-2 with all vaccinations. Pts who developed rising serum PSA levels on either arm could cross-over to receive both V and N. Initial data demonstrated a clinical benefit in pts treated with combination V and N. Pts characteristics were reviewed and OS was determined using the social security death index. Actuarial analyses of the data using the Kaplan-Meier method were performed. Results: The OS from on-study date in all randomized pts was 4.6 years (yrs) with 3yr OS=71% and 5yr OS=48%. There was no difference in OS in all pts based on Gleason Score (GS) or PSA at diagnosis (dx), orchiectomy, radical prostatectomy, or radiation therapy. However, a subgroup analysis showed a trend to improved OS for pts treated with V alone or V+N (compared to N alone or N+V), who had GS <7 (p=0.18), PSA<20 (p=0.077), and PSA doubling time<3 months (p=0.14). Comparing OS in the study arms: Conclusion: Although these results were not statistically significant due to small cohort sizes, there was a clear trend in both 3yr and 5yr OS in the pts who received V first and crossed-over to V+N, as compared with the reciprocal scheduling of N followed by N+V. A randomized trial at the NCI will compare androgen deprivation therapy (ADT) alone vs ADT plus vaccine to further study the benefits of combination therapy in this population. [Table: see text] No significant financial relationships to disclose.
A phase Ib/II study of PXD101 alone and in combination with 5-fluorouracil in patients with advanced solid tumors
Authors: Northfelt D. W. , Marschke R. F. , Bonnem E. , Ooi C. E. , Gerwien R. , Hawthorne T. , Clarke A. , Buhl-Jensen P. , Von Hoff D. , Grem J. 
Published: March 2020

3501 Background: PXD101 is a hydroxamate HDAC inhibitor that has broad anti-neoplastic activity in vivo and in vitro. Preclinical data showing PXD101 down-regulation of thymidylate synthase (TS), an in vivo target of 5-fluorouracil (5-FU) provide a rationale for combination of PXD101 with 5-FU. Methods: This is a phase Ib/II trial of PXD101 plus 5-FU in patients with advanced solid tumors, with dose escalation to establish the maximum tolerated dose (MTD) and an expansion at the MTD in colorectal cancer (CRC) patients. Patients (pts) must be = 18 yrs, have measurable disease, and had disease progression after standard chemotherapy. PXD101 was administered as a 30-min IV infusion on Days 1–5 of a 3-wk cycle. 5-FU was administered from cycle 2 on, as a continuous 96-hr IV infusion starting on Day 2 of the same 3-wk cycle. The primary endpoints were safety, and effect of belinostat on TS expression in patients’ tumors. Dose-limiting toxicities (DLTs) were PXD101-related = Gr 3 non-hematologic or Gr 4 hematologic toxicities. Expression of TS mRNA was measured by RTQ-PCR. Results: Twenty pts have been treated for a median of 2 cycles (range 1–8). Cohorts of 3–6 pts were tested at 5 dose levels of PXD101/5-FU (mg/m2/d): 300/250, 600/250, 1,000/250, 1,000/500, and 1,000/1,000. Two pts did not complete cycle 2, and one pt at the 600/250 dose level received 1,000 mg/m2/d 5-FU. There were no DLTs in the first 4 dose cohorts; the 5th cohort is ongoing. In the first 4 dose cohorts (17 pts), the most frequent AEs were fatigue, nausea/vomiting, dysgeusia, dehydration, constipation, edema, anorexia and anemia. There were 2 Gr 4 AEs (pulmonary embolism, bacteremia); Gr 3 AEs in = 2 pts were fatigue and dehydration. All Gr 3/4 events were assessed as not related to PXD101. One pt with stage IV CRC treated at 600/1,000 mg/m2/d PXD101/5-FU had stable disease (SD) for 8 cycles, and one pt with stage IV esophageal cancer treated at the 1,000/250 mg/m2/d dose had SD for 4 cycles. Conclusions: PXD101 in combination with 5-FU has been well tolerated up to 1,000/500 mg/m2/d PXD101/5-FU. The study is ongoing and data from the MTD expansion part, including effect of PXD101 on tumor TS expression, will be presented. No significant financial relationships to disclose.
Paclitaxel enhances antibody-dependent cell-mediated cytotoxicity of trastuzumab by a rapid recruitment of natural killer cells in Her-2 overexpressing breast cancer
Authors: Miura D. , Yoneyama K. , Furuhata Y. , Kawabata H. 
Published: March 2020

3503 Background: One of the important mechanisms that trastuzumab (TZ) inhibits the growth of Her-2 overexpressing breast cancer cells is the activation of a host tumor response via antibody-dependent cell-mediated cytotoxicity (ADCC). Although paclitaxel (PTX) has a synergistic effect in combination with TZ, whether the ADCC is enhanced by PTX is less known. We questioned whether adding PTX to TZ enhances ADCC and also investigated kinetics of effector cells in ADCC. Methods: Twenty-eight patients with Her-2 overexpression, 9 received the combination of (4mg/kg as a loading and 2 mg/kg weekly) and PTX (80 mg/m2 weekly) and 19 did monotherapy of TZ, were studied. Using blood samples (mononuclear cells) taken before and 10 minutes after administrations, ADCC and the number of effector cells including NK cell, monocyte, and CD64+ cell were compared in each case (after/before). ADCC was analyzed by 51Cr releasing assay using SK-BR-3 cell line and the fractions of NK cells (both CD16+(FcγRIII) and CD56+) and CD64+(FcγRI) cells were analyzed by flow cytometry. Results: ADCC levels increased in + 9% (mean) after TZ monotherapy and + 120% (p<0.05) after the combination of TZ and PTX. All 9 patients in combination had enhancements in ADCC levels. As regards effector cells, NK cells increased in + 51% after TZ alone and in + 112% (p<0.05) after the combination. No significant changes were found in monocytes (+ 39%) and CD64+ cells (+ 53%) after TZ, however monocytes decreased in - 40% (p<0.05) and also CD64+ in - 24% after the combination. Conclusions: Adding PTX to TZ significantly enhanced ADCC, which level was twice as strong as TZ monotherapy, by a rapid recruitment of NK cells. This may reflect that a combination of TZ and PTX has a strong synergistic effect than we expected in Her- 2 overexpressing breast cancer. No significant financial relationships to disclose.
Characterization of 89Zr-trastuzumab for clinical HER2 immunoPET imaging
Authors: Dijkers E. , Lub-de Hooge M. N. , Kosterink J. G. , Jager P. L. , Brouwers A. H. , Perk L. R. , van Dongen G. A. , de Vries E. G. 
Published: March 2020

3508 Background: SPECT imaging with 111In-DTPA-trastuzumab has recently identified new tumor lesions, undetected with conventional staging, in 13/15 patients with HER2++ breast cancers (Perik et al., J Clin Oncol 2006). The aim of this study was to develop an immunoPET label, suitable for clinical use, which would allow excellent detection of HER2 positive tumor lesions and quantification of HER2 expression levels in vivo. Methods: Trastuzumab has essentially been radiolabeled as described by Verel et al. (J Nucl Med 2003). Radiochemical purity (rcp) and stability were determined by SEC-HPLC, immunoreactivity with a Lindmo assay. Biodistribution was performed in nude mice bearing HER2 positive (SKOV3) or HER2 negative (GLC4) xenografts. Five animals per group were co-injected with 111In-ITC-DTPA-trastuzumab and 89Zr-trastuzumab, imaged on a microPET (Focus 220) and sacrificed 144 hours post injection. Results: The immunoreactive fraction of 89Zr-trastuzumab was 0.96, labeling efficiency > 90% and rcp > 95%. 89Zr-trastuzumab was stable for 7 days in buffer at 4 °C and in human serum at 37 °C. MicroPET imaging showed excellent tumor uptake and could easily detect metastases with a size approximating the spatial resolution of the microPET scanner. 89Zr- and 111In-ITC-DTPA-trastuzumab showed similar biodistribution. Highest uptake was found in HER2 positive tumors at 144 hours post injection (40% ID/g tissue for 89Zr-trastuzumab and 47% ID/g for 111In-ITC-DTPA-trastuzumab) compared to 8% ID/g tissue in HER2 negative control tumors. Liver uptake was low (8–12% ID/g tissue). Preliminary results in HER2 positive breast cancer patients show excellent tumor tracer uptake and a resolution unapproachable by 111In-DTPA-trastuzumab. Conclusions: 89Zr-trastuzumab is stable, shows excellent and specific tumor uptake and is suitable for clinical use. Minimal aspecific tracer uptake in the liver allows detection of abdominal metastases. No significant financial relationships to disclose.
The PI3-K/AKT/mTOR pathway as a target for breast cancer therapy
Authors: Di Cosimo S. , Scaltriti M. , Val D. , Rojo F. , Guzman M. , Jimenez J. , Seoane J. , Arribas J. , Baselga J. 
Published: March 2020

3511 Background: The PI3K/Akt/mTOR pathway is found dysregulated in multiple tumours, including breast cancer (BC). RAD001 is a recently developed drug which blocks mTOR. To study this compound’s anti-tumour effect and interactions with the aforementioned pathway, we set up a translational research program which integrates basic and clinical research data. Methods: The preclinal studies performed in BC cell lines and xenografts included the use of proliferation assays, western blot (WB), small interfering RNA and immunohistochemistry (IHC) analysis. The clinical studies consisted in a phase I study with escalating doses and collection of tumour biospies at different time points Results: Our first achievement was validating the antibodies used in WB and IHC and directed towards different components of the PI3K/Akt/mTOR pathway. We first reported that sensitivity to RAD001 correlated to basal levels of p-Akt. We then observed that RAD001 inhibits mTOR downstream, pS6 and eIF4G, but increases the levels of p-Akt, both in vitro and in patients’tumour biopsies. We demonstrated that knock down of the pS6 kinase mimics the effect of RAD001. Indeed, by combining the PI3K inhibitors and the genomic approch of p85 dominant negative vector, we demonstrated that RAD001 induced p-Akt is through PI3K. Besides the p-Akt induction we also found a RAD001 induction of IRS-1, the pivot mediator of the Insulin like Growth factor-1 Receptor (IGF-1R). We reported that RAD001 resulted in a prolonged activation of IRS-1 and in a sustained association with the p85 subunit of PI3K. Thus RAD001 disrupts an inhibitory mechanism impinging on the PI3K signalling, resulting in sustained activation of the IGF-1R pathway. Accordingly we demonstrated that combination of RAD001 with coumpounds directed against the IGF-1R, i.e. both IGF-1R tyrosine kinase inhibitors and monoclonal antibodies, prevented RAD001 induced p-Akt and resulted in a supradditive growth inhibitory effects both in vitro and in MCF-7 human BC derived xenografts.We are now conducting a phase I study with a monoclonal antibody directed at the IGF-1R that blocks IGF-1R signalling. Conclusions: Dual inhibition of mTOR and IGF-1R completely blocks the PI3K/Akt/mTOR pathway and provide a mechanistic-based combined approach. Clinical studies in BC patients are being planned. No significant financial relationships to disclose.
A phase I pharmacokinetic study of PR-104, a hypoxia-targeting agent, in patients with solid tumors
Authors: Jameson M. B. , Rischin D. , Pegram M. , Gutheil J. , Patterson A. , Denny W. , Wilson W. 
Published: March 2020

3516 Background: PR-104 is a novel pre-prodrug (precursor of a prodrug) designed to form a cytotoxic nitrogen mustard (alkylating agent) in hypoxic regions of tumors. Following IV administration, PR-104 is converted by systemic phosphatases to the alcohol intermediate PR-104A, which, under hypoxic conditions, is reduced to form the active DNA-crosslinking mustard species PR-104H. This phase I trial defines a Maximally Tolerated Dose (MTD) and pharmacokinetics (PK) for this schedule. Methods: Patients (pts) with relapsed/recurrent solid tumors received PR-104 as a 1-hour IV infusion every 3 weeks with PK sampling on days 1–2 of cycle 1. Cohorts of ≥3 pts were treated starting at 135 mg/m2. Results: 23 pts have been enrolled: median age 51 years (range 29–72); 13 (57%) male. Most pts had received prior radiation or chemotherapy and had metastatic disease. Six dose levels (135, 216, 354, 550, 770, and 1,100 mg/m2) have been evaluated. Dose-limiting toxicity (DLT) was observed in one patient at 1,100 mg/m2 (grade 3 fatigue) and this dose level was expanded to 6 pts. In the first 4 cohorts, 54 adverse events (AEs) were considered drug-related by the investigator including nausea (26% of all AEs), fatigue (19%), vomiting (11%) and anorexia (6%); remaining AEs each constituted < 3% of the total. Of 16 grade 3 AEs, 3 were considered drug-related by the investigator (anemia, dehydration and vomiting). Prophylactic anti-emetics largely prevented nausea and vomiting at higher doses, at which dose-related decreases in neutrophils and platelets were seen. Conclusions: PR-104 has shown manageable toxicities similar to other cytotoxic agents, with no serious mucositis, diarrhea or alopecia. DLT is likely to be myelosuppression based on preclinical and current clinical data, with the MTD close to 1,100 mg/m2. The preclinical PK target for the alcohol intermediate has been exceeded at higher doses and, while no objective responses have been documented, reductions in tumor volume have been seen at these doses. [Table: see text] No significant financial relationships to disclose.