Browsing by Subject "Trastuzumab"

Now showing 1 - 6 of 6
  • Thumbnail Image
    ItemOpen Access
    D-Amino acid peptide residualizing agents bearing N-hydroxysuccinimido- and maleimido-functional groups and their application for trastuzumab radioiodination.
    (Nucl Med Biol, 2015-01) Pruszynski, Marek; Koumarianou, Eftychia; Vaidyanathan, Ganesan; Chitneni, Satish; Zalutsky, Michael R
    INTRODUCTION: Proteins that undergo receptor-mediated endocytosis are subject to lysosomal degradation, requiring radioiodination methods that minimize loss of radioactivity from tumor cells after this process occurs. To accomplish this, we developed the residualizing radioiodination agent N(ϵ)-(3-[(*)I]iodobenzoyl)-Lys(5)-N(α)-maleimido-Gly(1)-D-GEEEK (Mal-D-GEEEK-[(*)I]IB), which enhanced tumor uptake but also increased kidney activity and necessitates generation of sulfhydryl moieties on the protein. The purpose of the current study was to synthesize and evaluate a new D-amino acid based agent that might avoid these potential problems. METHODS: N(α)-(3-iodobenzoyl)-(5-succinimidyloxycarbonyl)-D-EEEG (NHS-IB-D-EEEG), which contains 3 D-glutamates to provide negative charge and a N-hydroxysuccinimide function to permit conjugation to unmodified proteins, and the corresponding tin precursor were produced by solid phase peptide synthesis and subsequent conjugation with appropriate reagents. Radioiodination of the anti-HER2 antibody trastuzumab using NHS-IB-D-EEEG and Mal-D-GEEEK-IB was compared. Paired-label internalization assays on BT474 breast carcinoma cells and biodistribution studies in athymic mice bearing BT474M1 xenografts were performed to evaluate the two radioiodinated D-peptide trastuzumab conjugates. RESULTS: NHS-[(131)I]IB-D-EEEG was produced in 53.8%±13.4% and conjugated to trastuzumab in 39.5%±7.6% yield. Paired-label internalization assays with trastuzumab-NHS-[(131)I]IB-D-EEEG and trastuzumab-Mal-D-GEEEK-[(125)I]IB demonstrated similar intracellular trapping for both conjugates at 1h ((131)I, 84.4%±6.1%; (125)I, 88.6%±5.2%) through 24h ((131)I, 60.7%±6.8%; (125)I, 64.9%±6.9%). In the biodistribution experiment, tumor uptake peaked at 48 h (trastuzumab-NHS-[(131)I]IB-D-EEEG, 29.8%±3.6%ID/g; trastuzumab-Mal-D-GEEEK-[(125)I]IB, 45.3%±5.3%ID/g) and was significantly higher for (125)I at all time points. In general, normal tissue levels were lower for trastuzumab-NHS-[(131)I]IB-D-EEEG, with the differences being greatest in kidneys ((131)I, 2.2%±0.4%ID/g; (125)I, 16.9%±2.8%ID/g at 144 h). CONCLUSION: NHS-[(131)I]IB-D-EEEG warrants further evaluation as a residualizing radioiodination agent for labeling internalizing antibodies/fragments, particularly for applications where excessive renal accumulation could be problematic.
  • Thumbnail Image
    ItemOpen Access
    Distinct Receptor Tyrosine Kinase Subsets Mediate Anti-HER2 Drug Resistance in Breast Cancer.
    (J Biol Chem, 2017-01-13) Alexander, Peter B; Chen, Rui; Gong, Chang; Yuan, Lifeng; Jasper, Jeff S; Ding, Yi; Markowitz, Geoffrey J; Yang, Pengyuan; Xu, Xin; McDonnell, Donald P; Song, Erwei; Wang, Xiao-Fan
    Targeted inhibitors of the human epidermal growth factor receptor 2 (HER2), such as trastuzumab and lapatinib, are among the first examples of molecularly targeted cancer therapy and have proven largely effective for the treatment of HER2-positive breast cancers. However, approximately half of those patients either do not respond to these therapies or develop secondary resistance. Although a few signaling pathways have been implicated, a comprehensive understanding of mechanisms underlying HER2 inhibitor drug resistance is still lacking. To address this critical question, we undertook a concerted approach using patient expression data sets, HER2-positive cell lines, and tumor samples biopsied both before and after trastuzumab treatment. Together, these methods revealed that high expression and activation of a specific subset of receptor tyrosine kinases (RTKs) was strongly associated with poor clinical prognosis and the development of resistance. Mechanistically, these RTKs are capable of maintaining downstream signal transduction to promote tumor growth via the suppression of cellular senescence. Consequently, these findings provide the rationale for the design of therapeutic strategies for overcoming drug resistance in breast cancer via combinational inhibition of the limited number of targets from this specific subset of RTKs.
  • Thumbnail Image
    ItemOpen Access
    Effect at One Year of Adjuvant Trastuzumab for HER2+ Breast Cancer Combined with Radiation or an Anthracycline on Left Ventricular Ejection Fraction.
    (The American journal of cardiology, 2020-06) Andersen, Mousumi M; Ayala-Peacock, Diandra; Bowers, Jessie; Kooken, Banks W; D'Agostino, Ralph B; Jordan, Jennifer H; Vasu, Sujethra; Thomas, Alexandra; Klepin, Heidi D; Brown, Doris R; Hundley, W Gregory
    To determine the impact of radiation therapy (XRT) in addition to trastuzumab (TZB) adjuvant chemotherapy for HER2+ breast cancer on left ventricular systolic function, we assessed demographics, oncologic treatment history including XRT exposure, and serial measurements of left ventricular ejection fraction (LVEF) in 135 consecutively identified women receiving TZB for treatment of adjuvant breast cancer. Longitudinal mixed effects models were fit to identify baseline to treatment changes in LVEF among those receiving TZB with or without concomitant anthracycline or XRT. Women averaged 53 ± 3 years in age, 77% were white, 62% patients had 1 or more cardiovascular risk factors at baseline, and mean duration of TZB was 11 ± 5 months. Seventy-seven women were treated with XRT and received between 4000 and 5500 cGy of radiation. The LVEF declined by an average of 3.4% after 1 year for those in the study. Relative to baseline upon completion of adjuvant TZB, LVEF remained reduced for those receiving anthracycline with or without XRT (p=0.002 for both), or XRT alone (p=0.002), but not in those without these therapies. Amongst patients treated only with XRT and TZB, LVEF declined 3.1% on average in those with left-sided disease and 6.9% on average in those with right-sided disease (p= 0.06, p= 0.008 respectively). Among women receiving TZB for adjuvant treatment of HER-2 positive breast cancer, the administration of XRT, anthracycline, or the combination of the 2 is associated with a persistent post-treatment as opposed to a temporary treatment related decline in LVEF.
  • Thumbnail Image
    ItemOpen Access
    Population-level impact of adjuvant trastuzumab emtansine on the incidence of metastatic breast cancer: an epidemiological prediction model of women with HER2-positive early breast cancer and residual disease following neoadjuvant therapy.
    (Breast cancer (Tokyo, Japan), 2024-01) Williamson, Mellissa; Press, David J; Hansen, Svenn Alexander; Tomar, Akanksha; Jhuti, Gurleen Singh; Revil, Cedric; Gururaj, Kaustubh

    Purpose

    Treating early-stage breast cancer (eBC) may delay or prevent subsequent metastatic breast cancer (mBC). In the phase 3 KATHERINE study, women with human epidermal growth factor receptor 2 (HER2)-positive eBC with residual disease following neoadjuvant therapy containing trastuzumab and a taxane experienced 50% reductions in disease recurrence or death when treated with adjuvant trastuzumab emtansine (T-DM1) vs adjuvant trastuzumab. We predicted the population-level impact of adjuvant T-DM1 on mBC occurrence in five European countries (EU5) and Canada from 2021-2030.

    Methods

    An epidemiological prediction model using data from national cancer registries, observational studies, and clinical trials was developed. Assuming 80% population-level uptake of adjuvant treatment, KATHERINE data were extrapolated prospectively to model projections. Robustness was evaluated in alternative scenarios.

    Results

    We projected an eligible population of 116,335 women in Canada and the EU5 who may be diagnosed with HER2-positive eBC and have residual disease following neoadjuvant therapy from 2021-2030. In EU5, the cumulative number of women projected to experience relapsed mBC over the 10-year study period was 36,009 vs 27,143 under adjuvant trastuzumab vs T-DM1, a difference of 8,866 women, equivalent to 25% fewer cases with the use of adjuvant T-DM1 in EU5 countries from 2021-2030. Findings were similar for Canada.

    Conclusion

    Our models predicted greater reductions in the occurrence of relapsed mBC with adjuvant T-DM1 vs trastuzumab in the indicated populations in EU5 and Canada. Introduction of T-DM1 has the potential to reduce population-level disease burden of HER2-positive mBC in the geographies studied.
  • Thumbnail Image
    ItemOpen Access
    Simultaneous Detection of Multiple Tumor-targeted Gold Nanoparticles in HER2-Positive Breast Tumors Using Optoacoustic Imaging.
    (Radiology. Imaging cancer, 2023-05) Samykutty, Abhilash; Thomas, Karl N; McNally, Molly; Hagood, Jordan; Chiba, Akiko; Thomas, Alexandra; McWilliams, Libby; Behkam, Bahareh; Zhan, Ying; Council-Troche, McAlister; Claros-Sorto, Juan C; Henson, Christina; Garwe, Tabitha; Sarwar, Zoona; Grizzle, William E; McNally, Lacey R
    Purpose To develop optoacoustic, spectrally distinct, actively targeted gold nanoparticle-based near-infrared probes (trastuzumab [TRA], TRA-Aurelia-1, and TRA-Aurelia-2) that can be individually identifiable at multispectral optoacoustic tomography (MSOT) of human epidermal growth factor receptor 2 (HER2)-positive breast tumors. Materials and Methods Gold nanoparticle-based near-infrared probes (Aurelia-1 and 2) that are optoacoustically active and spectrally distinct for simultaneous MSOT imaging were synthesized and conjugated to TRA to produce TRA-Aurelia-1 and 2. Freshly resected human HER2-positive (n = 6) and HER2-negative (n = 6) triple-negative breast cancer tumors were treated with TRA-Aurelia-1 and TRA-Aurelia-2 for 2 hours and imaged with MSOT. HER2-expressing DY36T2Q cells and HER2-negative MDA-MB-231 cells were implanted orthotopically into mice (n = 5). MSOT imaging was performed 6 hours following the injection, and the Friedman test was used for analysis. Results TRA-Aurelia-1 (absorption peak, 780 nm) and TRA-Aurelia-2 (absorption peak, 720 nm) were spectrally distinct. HER2-positive human breast tumors exhibited a significant increase in optoacoustic signal following TRA-Aurelia-1 (28.8-fold) or 2 (29.5-fold) (P = .002) treatment relative to HER2-negative tumors. Treatment with TRA-Aurelia-1 and 2 increased optoacoustic signals in DY36T2Q tumors relative to those in MDA-MB-231 controls (14.8-fold, P < .001; 20.8-fold, P < .001, respectively). Conclusion The study demonstrates that TRA-Aurelia 1 and 2 nanoparticles operate as a spectrally distinct HER2 breast tumor-targeted in vivo optoacoustic agent. Keywords: Molecular Imaging, Nanoparticles, Photoacoustic Imaging, Breast Cancer Supplemental material is available for this article. © RSNA, 2023.
  • Thumbnail Image
    ItemOpen Access
    X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.
    (Cell Death Dis, 2016-01-28) Evans, MK; Sauer, SJ; Nath, S; Robinson, TJ; Morse, MA; Devi, GR
    Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy.