Citations

Abstract This report describes results from our analysis of the activity and biodistribution of a novel pan-ERBB inhibitor, NT113, when used in treating mice with intracranial glioblastoma (GBM) xenografts. Approaches used in this investigation include: bioluminescence imaging (BLI) for monitoring intracranial tumor growth and response to therapy; determination of survival benefit from treatment; analysis of tumor IHC reactivity for indication of treatment effect on proliferation and apoptotic response; Western blot analysis for determination of effects of treatment on ERBB and ERBB signaling mediator activation; and high-performance liquid chromatography for determination of NT113 concentration in tissue extracts from animals receiving oral administration of inhibitor. Our results show that NT113 is active against GBM xenografts in which wild-type EGFR or EGFRvIII is highly expressed. In experiments including lapatinib and/or erlotinib, NT113 treatment was associated with the most substantial improvement in survival, as well as the most substantial tumor growth inhibition, as indicated by BLI and IHC results. Western blot analysis results indicated that NT113 has inhibitory activity, both in vivo and in vitro, on ERBB family member phosphorylation, as well as on the phosphorylation of downstream signaling mediator Akt. Results from the analysis of animal tissues revealed significantly higher NT113 normal brain-to-plasma and intracranial tumor-to-plasma ratios for NT113, relative to erlotinib, indicating superior NT113 partitioning to intracranial tissue compartments. These data provide a strong rationale for the clinical investigation of NT113, a novel ERBB inhibitor, in treating patients with GBM. Mol Cancer Ther; 13(12); 2919–29. ©2014 AACR.

Abstract Background Scientists working in the field of xenotransplantation do not employ a uniform method to measure and report natural and induced antibody responses to non‐ G alα(1,3) G al (non‐ G al) epitopes. Such humoral responses are thought to be particularly pathogenic after transplantation of vascularized Gal TKO pig organs and having a more uniform assay and reporting format would greatly facilitate comparisons between laboratories. Methods Flow cytometry allows examination of antibody reactivity to intact antigens in their natural location and conformation on cell membranes. We have established a simple and reproducible flow cytometric assay to detect antibodies specific for non‐ G al pig antigens using primary porcine aortic endothelial cells ( pAEC s) and cell culture‐adapted pAEC cell lines generated from wild type and α1,3galactosyl transferase knockout (Gal TKO ) swine. Results The consensus protocol we propose here is based on procedures routinely used in four xenotransplantation centers and was independently evaluated at three sites using shared cells and serum samples. Our observation support use of the cell culture‐adapted Gal TKO pAEC KO :15502 cells as a routine method to determine the reactivity of anti‐non‐ G al antibodies in human and baboon serum. Conclusions We have developed an assay that allows the detection of natural and induced non‐Gal xenoreactive antibodies present in human or baboon serum in a reliable and consistent manner. This consensus assay and format for reporting the data should be accessible to laboratories and will be useful for assessing experimental results between multiple research centers. Adopting this assay and format for reporting the data should facilitate the detection, monitoring, and detailed characterization of non‐ G al antibody responses.

Abstract Background: Epidermal Growth Factor Receptor (EGFR, HER1) is known to heterodimerize with HER2 and may impact the effectiveness of trastuzumab. Historically, EGFR has been difficult to measure; thus there is no evidence regarding its effects on trastuzumab clinical therapy. Here we use a new, standardized, quantitative immunofluorescence assay and a novel EGFR antibody to evaluate the correlation between EGFR expression and clinical outcome in a cohort from the North Central Cancer Treatment Group (NCCTG, Alliance) N9831 trial. Methods: Of the 3505 women in the N9831 trial, tissue microarrays were constructed that allowed analysis of 1,444 patients randomly assigned to receive chemotherapy alone (Arm A), sequential trastuzumab after chemotherapy (Arm B) or concurrent trastuzumab with chemotherapy (Arm C). Fluorescence-based, standardized measurement of EGFR was done using the rabbit monoclonal EGFR antibody D38B1 on the AQUA platform (HistoRx). EGFR expression levels were analyzed as a continuous variable and dichotomized using recursive partitioning to define an optimal cut point. The cut point was validated on an independent retrospective cohort comprised of 130 patients with HER2-positive metastatic breast cancer who received trastuzumab. Results: EGFR assessed as a continuous variable shows an association with disease free survival (DFS) in Arm C (p = 0.002) but not in Arms A or B. Dichotomizing EGFR expression shows that high level expression is associated with worse outcome (HR = 2.2; 95% CI 1.33–3.59, p = 0.002) in arm C. Five year DFS within the low level EGFR expression group was 71%, 74% and 90% for Arms A, B and C, respectively (log-rank p-value=0.02) and within the high level EGFR expression (n = 213) group was 62%, 76% and 74% respectively (log-rank p-value 0.22). As validation, the same cut-point was used to define high EGFR expression in a retrospective metastatic breast cancer cohort. The median progression free survival difference between EGFR high group and EGFR low group was 6.1 months (p = 0.0063) and the hazard ratio of high EGFR was 1.92 (p = 0.0073). Conclusions: High expression of EGFR by the AQUA platform appears to be associated with decreased benefit from adjuvant concurrent (not sequential) trastuzumab and shorter PFS in the metastatic setting. The biological underpinning for these observations is being considered. Since there are other treatment options for HER2-driven tumors, this marker, once validated, could help select patients for alternative or additive therapy. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S5-4.

Abstract Background: Endoxifen (Endx) is being developed as a drug for patients with estrogen receptor (ER)+ breast cancer (BC). We previously demonstrated that Endx was superior to TAM in both a letrozole (L) sensitive and resistant MCF7/AC1 model. Tamoxifen (TAM) and its most commonly studied metabolite, 4-hydroxy TAM (4HT), are known to activate critical ER co-regulators such as SRC3, which are oncogenic, and contribute to acquired and de novo endocrine resistance. While both Endx and 4HT are more potent inhibitors of genomic ERα functions compared to TAM, the effects of Endx on non-genomic signaling have not been characterized and its efficacy as an anti-cancer agent compared to RAD001 in AI resistant BC is unknown. Methods: We evaluated the 1 hour in vitro effects of TAM, 4HT, Endx, and L, in terms of activation of multiple signaling cascades using an MCF7/AC1 L-resistant cells and long term estrogen deprived (LTED) cells (MDA 361 and ZR75). Protein Docking studies (shape screening, pharmacophore modeling and ligand-protein docking) for oncogenic kinases, and their associated IC50's were determined for TAM and Endx. The in vivo activity of Endx (50 mg/kg, oral) was determined in MCF/AC1 L-resistant xenograft tumors and compared with L control (10 ug/day, sc), Exemestane (E) (250 ug/d, sc) and E+RAD001 (2.5 mg/kg/d, oral). Results: In MCF7/AC1 L-resistant cells, 1 hr treatment with either TAM (100 nM or 5 uM) or 4HT (100 nM or 5 uM) phosphorylated SRC3 (AIB1) and resulted in downstream activation (phosphorylation) of IGF1R, PDK1, AKT, and p70S6K. In contrast, Endx (100 nM and 5 uM) did not phosphorylate SRC3 nor any downstream kinases but resulted in a dose dependent decrease in AKT phosphorylation. Similar findings were observed in LTED cells MDA 361 and ZR75. Docking studies identified a significant decrease in the binding energy (>2 kcal/mol) of Endx compared to TAM for PKC and PI3K and subsequent kinase profiling demonstrated that Endx more potently inhibits PKCβ1 (IC50 357nM) and PI3KΔ (2.5uM) compared to TAM (IC50 4.8μM and 6.2μM respectively). Therefore, we evaluated the in vivo anti-tumor activity of Endx with E and E+RAD001 in MCF7 L-resistant xenograft tumors. After 9 weeks, the% change in tumor volume relative to baseline was significantly lower for both Endx (median -34%, p = 0.0002) and E+RAD001 (median +1.5%, p = 0.0002) as compared to L controls (median +301%). In contrast, E alone was non-significantly lower (median +172%, (p = 0.09). No significant differences were observed comparing Endx and E+RAD001 (p = 0.56). Conclusions: Endx inhibits PKCβ1 and PI3KΔ at concentrations that are pharmacologically relevant, and unlike TAM and 4HT, does not activate SRC3 nor induce oncogenic signaling pathways in AI resistant cells. Importantly, Endx elicits substantial anti-tumor effects in AI resistant models that are similar to the current standard of care of E+RAD001. These data suggest that Endx may be superior to TAM for the treatment of ER+ BC and may result in clinical benefit for patients with AI resistant disease. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-09-08.

Objectives Debriefing is a common feature of technology‐enhanced simulation ( TES ) education. However, evidence for its effectiveness remains unclear. We sought to characterise how debriefing is reported in the TES literature, identify debriefing features that are associated with improved outcomes, and evaluate the effectiveness of debriefing when combined with TES . Methods We systematically searched databases, including MEDLINE , EMBASE and Scopus, and reviewed previous bibliographies for original comparative studies investigating the use of TES with debriefing in training health care providers. Reviewers, in duplicate, evaluated study quality and abstracted information on instructional design, debriefing and outcomes. Effect sizes ( ES ) were pooled using random‐effects meta‐analysis. Results From 10 903 potentially eligible studies, we identified 177 studies (11 511 learners) that employed debriefing as part of TES . Key characteristics of debriefing (e.g. duration, educator presence and characteristics, content, structure/method, timing, use of video) were usually incompletely reported. A meta‐analysis of four studies demonstrated that video‐assisted debriefing has negligible and non‐significant effects for time skills ( ES = 0.10) compared with non‐video‐assisted debriefing. Meta‐analysis demonstrated non‐significant effects in favour of expert modelling with short debriefing in comparison with long debriefing (ES range = 0.21–0.74). Among studies comparing terminal with concurrent debriefing, results were variable depending on outcome measures and the context of training (e.g. medical resuscitation versus technical skills). Eight additional studies revealed insight into the roles of other debriefing‐related factors (e.g. multimedia debriefing, learner‐led debriefing, debriefing duration, content of debriefing). Among studies that compared simulation plus debriefing with no intervention, pooled ES s were favourable for all outcomes (ES range = 0.28–2.16). Conclusions Limited evidence suggests that video‐assisted debriefing yields outcomes similar to those of non‐video‐assisted debriefing. Other debriefing design features show mixed or non‐significant results. As debriefing characteristics are usually incompletely reported, future debriefing research should describe all the key debriefing characteristics along with their associated descriptors.

BACKGROUNDWith the advent of limits to resident duty hours and the size of teaching services, many academic institutions have introduced nonteaching services, often triaging perceived better teaching cases to the resident services.OBJECTIVETo compare resident versus faculty perceptions of ideal cases for teaching services and compare these perceptions with actual triage decisions made by faculty who assigned patients to either teaching or nonteaching services.DESIGNResidents and hospitalist faculty were surveyed about their perceptions of ideal and actual teaching admissions, first with qualitative, open‐ended questions and then with quantitative, specific questions generated from responses to the first survey. Characteristics of patients admitted to teaching and nonteaching services were analyzed retrospectively and compared with resident and faculty perceptions.RESULTSResidents and faculty agreed that rare cases, patients with unique physical findings, and a variety of pathology were ideal for teaching services and that social admissions, benefactors, and patients with chronic or functional pain were not. Residents believed that traditional (“bread and butter”) medicine cases were under‐represented on the teaching services. Although residents perceived that they received a disproportionate number of older patients, outside transfers, patients with chronic pain, and patients with cancer, the only statistically significant difference was in patient age, with the teaching service actually receiving younger patients (66.7 vs 69.3 years; P = 0.008).CONCLUSIONSResidents and faculty have similar views about ideal teaching cases, but a triage system based on perceived educational merit creates the possibility of resident misperceptions about their case mix, even if patients are distributed relatively equitably. Journal of Hospital Medicine 2014;9:508–514. © 2014 Society of Hospital Medicine

Key Points VTE recurrence risk in patients with cancer can be stratified by cancer type, stage, stage progression, and presence of leg paresis. Patients with cancer at high VTE recurrence risk should be considered for secondary prophylaxis.