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New Philadelphia, PA, United States

Ascierto P.A.,Unit of Melanoma | Kalos M.,Abramson Family Cancer Research Institute | Kalos M.,University of Pennsylvania | Schaer D.A.,Sloan Kettering Cancer Center | And 5 more authors.
Clinical Cancer Research

Modulation of the immune system by targeting coinhibitory and costimulatory receptors has become a promising newapproach of immunotherapy for cancer. The recent approval of the CTLA-4-blocking antibody ipilimumab for the treatment of melanoma was a watershed event, opening up a new era in the field of immunotherapy. Ipilimumab was the first treatment to ever show enhanced overall survival (OS) for patients with stage IVmelanoma. However, measuring response rates using standard Response Evaluation Criteria in Solid Tumors (RECIST) or modified World Health Organization criteria or progression-free survival does not accurately capture the potential for clinical benefit for ipilimumab-treated patients. As immunotherapy approaches are translated into more tumor types, it is important to study biomarkers, which may be more predictive of OS to identify the patients most likely to have clinical benefit. Ipilimumab is the first-in-class of a series of immunomodulating antibodies that are in clinical development. Anti-PD1 (nivolumab and MK-3475), anti-PD-L1 (BMS-936 559, RG7446, and MEDI4736), anti-CD137 (urelumab), anti-OX40, anti- GITR, and anti-CD40 monoclonal antibodies are just some of the agents that are being actively investigated in clinical trials, each having the potential for combination with the ipilimumab to enhance its effectiveness. Development of rational combinations of immunomodulatory antibodies with small-molecule pathway inhibitor therapies such as vemurafenib makes the discovery of predictive biomarkers even more important. Identifying reliable biomarkers is a necessary step in personalizing the treatment of each patient's cancer through a baseline assessment of tumor gene expression and/or immune profile to optimize therapy for the best chance of therapeutic success. © 2012 American Association for Cancer Research. Source

Beatty G.L.,University of Pennsylvania | Torigian D.A.,University of Pennsylvania | Gabriela Chiorean E.,University of Washington | Saboury B.,University of Pennsylvania | And 8 more authors.
Clinical Cancer Research

Purpose: This phase I study investigated the maximum-tolerated dose (MTD), safety, pharmacodynamics, immunologic correlatives, and antitumor activity of CP-870,893, an agonist CD40 antibody, when administered in combination with gemcitabine in patients with advanced pancreatic ductal adenocarcinoma (PDA). Experimental Design: Twenty-two patients with chemotherapy-naive advanced PDA were treated with 1,000 mg/m2 gemcitabine once weekly for three weeks with infusion of CP-870,893 at 0.1 or 0.2 mg/kg on day three of each 28-day cycle. Results: CP-870,893 was well-tolerated; one dose-limiting toxicity (grade 4, cerebrovascular accident) occurred at the 0.2 mg/kg dose level, which was estimated as the MTD. The most common adverse event was cytokine release syndrome (grade 1 to 2). CP-870,893 infusion triggered immune activation marked by an increase in inflammatory cytokines, an increase in B-cell expression of costimulatory molecules, and a transient depletion of B cells. Four patients achieved a partial response (PR). 2-[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) showed more than 25% decrease in FDG uptake within primary pancreatic lesions in six of eight patients; however, responses observed in metastatic lesions were heterogeneous, with some lesions responding with complete loss of FDG uptake, whereas other lesions in the same patient failed to respond. Improved overall survival correlated with a decrease in FDG uptake in hepatic lesions (R = -0.929; P - 0.007). Conclusions: CP-870,893 in combination with gemcitabine was well-tolerated and associated with antitumor activity in patients with PDA. Changes in FDG uptake detected on PET/CT imaging provide insight into therapeutic benefit. Phase II studies are warranted. Clin Cancer Res; 19(22); 6286-95. © 2013 AACR. © 2013 American Association for Cancer Research. Source

Thiel A.T.,University of Pennsylvania | Blessington P.,University of Pennsylvania | Zou T.,Abramson Family Cancer Research Institute | Feather D.,University of Pennsylvania | And 7 more authors.
Cancer Cell

Oncogenic fusion proteins are capable of initiating tumorigenesis, but the role of their wild-type counterparts in this process is poorly understood. The mixed lineage leukemia (MLL) gene undergoes chromosomal translocations, resulting in the formation of oncogenic MLL fusion proteins (MLL-FPs). Here, we show that menin recruits both wild-type MLL and oncogenic MLL-AF9 fusion protein to the loci of HOX genes to activate their transcription. Wild-type MLL not only catalyzes histone methylation at key target genes but also controls distinct MLL-AF9-induced histone methylation. Notably, the wild-type Mll allele is required for MLL-AF9-induced leukemogenesis and maintenance of MLL-AF9-transformed cells. These findings suggest an essential cooperation between an oncogene and its wild-type counterpart in MLL-AF9-induced leukemogenesis. © 2010 Elsevier Inc. All rights reserved. Source

Yzaguirre A.D.,Abramson Family Cancer Research Institute | Speck N.A.,Abramson Family Cancer Research Institute
Developmental Biology

The de novo generation of hematopoietic cells occurs during midgestation when a population of endothelial cells called hemogenic endothelium transitions into hematopoietic progenitors and stem cells. In mammalian embryos, the newly formed hematopoietic cells form clusters in the lumens of the major arteries in the embryo proper and in the vascular plexus of the yolk sac. Small clusters of hematopoietic cells that are independent of the vasculature (referred to here as extravascular islands) were shown to form in the mesentery during vascular remodeling of the vitelline artery. Using three-dimensional imaging of whole mouse embryos we demonstrate that extravascular budding of hematopoietic clusters is a more widespread phenomenon that occurs from the vitelline and the umbilical arteries both proximal to the embryo proper and distal in the extraembryonic yolk sac and placenta. Furthermore, we show that there are several mechanisms by which hematopoietic clusters leave the arteries, including vascular remodeling and extrusion. Lastly, we provide static images suggesting that extravascular islands contribute to the formation of new blood vessels. Thus, extravascular islands may represent a novel mechanism of vasculogenesis whereby established vessels contribute endothelial and hematopoietic cells to developing vascular beds. © 2016 Elsevier Inc. Source

Dilley R.L.,Abramson Family Cancer Research Institute | Greenberg R.A.,Abramson Family Cancer Research Institute
Trends in Cancer

Activation of a telomere maintenance mechanism (TMM) is permissive for replicative immortality and a hallmark of human cancer. While most cancers rely on reactivation of telomerase, a significant fraction utilizes the recombination-dependent alternative lengthening of telomeres (ALT) pathway. ALT is enriched in tumors of mesenchymal origin, including those arising from bone, soft tissue, and the nervous system, and usually portends a poor prognosis. Recent insights into the mechanisms of ALT are uncovering novel avenues to exploit vulnerabilities and may facilitate clinical development of ALT-detection assays and personalized treatment decisions based on TMM status. Treatments targeting ALT may hold promise for a broadly-applicable therapeutic modality specific to mesenchymal lineage tumors, something that has thus far remained elusive. © 2015 Elsevier Ltd. Source

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