Treatment Of HER2-positive Breast Cancer Research Articles

Intravenous administration of cardiac progenitor cell-derived exosomes protects against doxorubicin/trastuzumab-induced cardiac toxicity.

Combined administration of anthracyclines (e.g. doxorubicin; Dox) and trastuzumab (Trz), a humanized anti-human epidermal growth factor receptor 2 (HER2; ErbB2), is an effective treatment for HER2-positive breast cancer. However, both agents are associated with cardiac toxicity. Human cardiac-resident mesenchymal progenitor cells (CPCs) secrete extracellular vesicles including nanosized exosomes which protect against myocardial ischaemia. Here, we investigated the effects of these exosomes using a novel model of Dox/Trz-mediated cardiotoxicity. CPCs were derived from cardiac atrial appendage specimens from patients who underwent heart surgery for heart valve disease and/or ischaemic heart disease, and exosomes were purified from CPC conditioned media. Proteomics analyses revealed that CPC exosomes contained multiple proteins involved in redox processes. Dox/Trz induced a significant increase in reactive oxygen species (ROS) in rat cardiomyocytes, which was prevented by CPC exosomes. In vivo, rats received six doses of Dox (Days 1-11), followed by six doses of Trz (Days 19-28). Three doses of either exosomes or exosome suspension vehicle were injected intravenously on Days 5, 11, and 19 in the treatment and control groups, respectively. Dox/Trz induced myocardial fibrosis, CD68+ inflammatory cell infiltrates, inducible nitric oxide synthase expression, and left ventricular dysfunction. CPC exosomes prevented these effects. These vesicles were highly enriched in miR-146a-5p compared with human dermal fibroblast exosomes. Dox upregulated Traf6 and Mpo, two known miR-146a-5p target genes (which encode signalling mediators of inflammatory and cell death axes) in myocytes. CPC exosomes suppressed miR-146a-5p target genes Traf6, Smad4, Irak1, Nox4, and Mpo in Dox-treated cells. Specific silencing of miR-146a-5p abrogated exosome-mediated suppression of those genes leading to an increase in Dox-induced cell death. Human CPC exosomes attenuate Dox-/Trz-induced oxidative stress in cardiomyocytes. Systemic administration of these vesicles prevents Dox/Trz cardiotoxicity in vivo. miR-146a-5p mediates some of the benefits of exosomes in this setting.

Trastuzumab-Modified Gold Nanoparticles Labeled with 211At as a Prospective Tool for Local Treatment of HER2-Positive Breast Cancer.

Highly localized radiotherapy with radionuclides is a commonly used treatment modality for patients with unresectable solid tumors. Herein, we propose a novel α-nanobrachytherapy approach for selective therapy of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This uses local intratumoral injection of 5-nm-diameter gold nanoparticles (AuNPs) labeled with an α-emitter (211At), modified with polyethylene glycol (PEG) chains and attached to HER2-specific monoclonal antibody (trastuzumab). The size, shape, morphology, and zeta potential of the 5 nm synthesized AuNPs were characterized by TEM (Transmission Electron Microscopy) and DLS (Dynamic Light Scattering) techniques. The gold nanoparticle surface was modified by PEG and subsequently used for antibody immobilization. Utilizing the high affinity of gold for heavy halogens, the bioconjugate was labelled with 211At obtained by α irradiation of the bismuth target. The labeling yield of 211At was greater than 99%. 211At bioconjugates were stable in human serum. Additionally, in vitro biological studies indicated that 211At-AuNP-PEG-trastuzumab exhibited higher affinity and cytotoxicity towards the HER2-overexpressing human ovarian SKOV-3 cell line than unmodified nanoparticles. Confocal and dark field microscopy studies revealed that 211At-AuNP-PEG-trastuzumab was effectively internalized and deposited near the nucleus. These findings show promising potential for the 211At-AuNP-PEG-trastuzumab radiobioconjugate as a perspective therapeutic agent in the treatment of unresectable solid cancers expressing HER2 receptors.

Cytotoxicity of Sodium Arsenite-loaded Anti-HER2 Immunoliposomes Against HER2-expressing Human Breast Cancer Cell Lines

Background: Chemotherapy is a routine approach in treatment of patients with cancer, while side effects of chemotherapeutic drugs are inevitable. To minimize side effects, specific targeting of neoplastic cells is a promising strategy in cancer therapy. Sodium arsenite is a metalloid toxin with anti-neoplastic properties, but low selectivity and carcinogenic activity have limited its clinical usage. Methods: Targeting of HER2-overexpressing (SK-BR-3) and HER2-low expressing (MCF-7) cancerous breast cell lines by two different liposomal forms of sodium arsenite (bare liposome and trastuzumab-conjugated liposome) was investigated in the current study. Levels of HER2 expression in the above mentioned cell lines were confirmed by western blotting. Size and morphology of the constructed liposomes were characterized by atomic force microscopy (AFM) and dynamic light scattering (DLS). Viability of the cells after treatment was assessed using MTT assay. Results: Sodium arsenite in the free and liposomal forms showed growth inhibitory effects against both SK-BR-3 and MCF-7 cell lines in an examined concentration range of 1-20 µM, although this effect was more significant in SK-BR-3 cell line. Loading of sodium arsenite in anti-HER2 immunoliposomes significantly enhanced its cytotoxicity while the specificity was also improved. By encapsulation of sodium arsenite in anti-HER2 immunoliposomes, its efficacy in ablation of SKBR- 3 cells was increased about 1.4-fold compared to the free or liposomal forms. Conclusion: In conclusion, targeted delivery of sodium arsenite using anti-HER2 immunoliposomes can be considered as an alternative strategy for specific treatment of HER2-positive breast cancers.

Advances in the Treatment of HER2-Positive Breast Cancer

Advances in the Treatment of HER2-Positive Breast Cancer

The Effects of Pertuzumab and Its Combination with Trastuzumab on HER2 Homodimerization and Phosphorylation.

Pertuzumab (Perjeta) is an anti-HER2 monoclonal antibody that is used for treatment of HER2-positive breast cancers in combination with trastuzumab (Herceptin) and docetaxel and showed promising clinical outcomes. Pertuzumab is suggested to block heterodimerization of HER2 with EGFR and HER3 that abolishes canonical function of HER2. However, evidence on the exact mode of action of pertuzumab in homodimerization of HER2 are limited. In this study, we investigated the effect of pertuzumab and its combination with trastuzumab on HER2 homodimerization, phosphorylation and whole gene expression profile in Chinese hamster ovary (CHO) cells stably overexpressing human HER2 (CHO-K6). CHO-K6 cells were treated with pertuzumab, trastuzumab, and their combination, and then HER2 homodimerization and phosphorylation at seven pY sites were investigated. The effects of the monoclonal antibodies on whole gene expression and the expression of cell cycle stages, apoptosis, autophagy, and necrosis were studied by cDNA microarray. Results showed that pertuzumab had no significant effect on HER2 homodimerization, however, trastuzumab increased HER2 homodimerization. Interestingly, pertuzumab increased HER2 phosphorylation at Y1127, Y1139, and Y1196 residues, while trastuzumab increased HER2 phosphorylation at Y1196. More surprisingly, combination of pertuzumab and trastuzumab blocked the phosphorylation of Y1005 and Y1127 of HER2. Our results also showed that pertuzumab, but not trastuzumab, abrogated the effect of HER2 overexpression on cell cycle in particular G1/S transition, G2/M transition, and M phase, whereas trastuzumab abolished the inhibitory effect of HER2 on apoptosis. Our findings confirm that pertuzumab is unable to inhibit HER2 homodimerization but induces HER2 phosphorylation at some pY sites that abolishes HER2 effects on cell cycle progress. These data suggest that the clinical effects of pertuzumab may mostly through the inhibition of HER2 heterodimers, rather than HER2 homodimers and that pertuzumab binding to HER2 may inhibit non-canonical HER2 activation and function in non-HER-mediated and dimerization-independent pathway(s).

Cost-Effectiveness Analysis of Pertuzumab With Trastuzumab and Chemotherapy Compared to Trastuzumab and Chemotherapy in the Adjuvant Treatment of HER2-Positive Breast Cancer in the United States

ObjectiveThe APHINITY trial assessed the effectiveness and the safety of adding pertuzumab to trastuzumab and chemotherapy (THP) compared to trastuzumab and chemotherapy (TH) in the adjuvant management of human epidermal growth factor 2-positive (HER2+) breast cancer. We performed a study to project the potential cost-effectiveness of THP vs. TH. Study DesignTrial-based cost-utility modeling analysis. MethodsWe performed an economic evaluation from a payer perspective using a Markov model with six health states: invasive disease-free survival, non-metastatic recurrence, remission, first-line metastatic, subsequent line metastatic, and death. We parameterized the model using data from both arms in APHINITY extrapolated to a patient’s lifetime horizon. Estimates of health state utilities were based on EQ-5D trial data and the literature, and costs were estimated from government sources and the published literature. The primary outcomes of the model were life-years (LYs), quality-adjusted LYs (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Uncertainty was addressed via univariate and probabilistic sensitivity analyses. ResultsFor the intention-to-treat population, the model projected improved outcomes (by 0.50 LYs and 0.45 QALYs) and increased costs (by $74 420) for ICERs of $147 774/LY gained and $167 185/QALY gained for PHT vs. HT patients. In the node-positive patient population, the model projected improved outcomes (by 0.86 LYs and 0.76 QALYs) and increased costs (by $66 647) for ICERs of $77 684/LY gained and $87 929/QALY gained. For the hormone-receptor-negative patient population, the model projected health gains, increased costs, and ICERs of $147 022/LY gained and $166 518/QALY gained. The results were sensitive to changes in the model time horizon. ConclusionThe addition of pertuzumab to the available regimens for HER2+ early breast cancer is likely to be cost-effective for patients in the U.S. at high risk of recurrence.

Abstract P6-17-39: BAT8001, a potent anti-HER2 antibody-drug conjugate with a novel stable linker for the treatment of HER2-positive breast cancer

Abstract Overexpression of HER2 occurs in approximately 20% of breast cancers and is associated with shortened survival. Trastuzumab emtansine (T-DM1), an anti-HER2 ADC, has shown efficacy in HER2-positive breast cancer patients and was approved by the FDA and EMA for advanced HER2-positive breast cancer. However T-DM1 causes grade 3 and 4 thrombocytopenia in up to 14.5% of patients as its major toxicity. The thrombocytopenia is likely caused by one of T-DM1's catabolites and payload, DM1, indicating T-DM1's linker can be cleaved. Here we adopted a novel noncleavable linker and created an anti-HER2 ADC, BAT8001, which is expected be efficacious in HER2-positive breast cancer and have a better side effect profile relative to T-DM1 due to the stability of BAT8001's noncleavable linker. BAT8001 is internalized in HER2-positive cancer cells. It inhibits proliferation of HER2-positive tumor cells with IC50s of ˜0.1 nM, similar to the potency of T-DM1. BAT8001 also induces apoptosis in HER2-positive cancer cells. In both cell-line and patient-derived mouse xenograft (PDX) models, BAT8001 demonstrates strong inhibition activity on tumor growth. For example, in a cell-line model of breast cancer (BT474), BAT8001 demonstrates potent activity with complete responses in all animals tested at the 15mg/kg dose level. Pharmacokinetics studies in monkey reveals BAT8001 has similar Cmax, AUC, and t1/2 as T-DM1. The major catabolite of BAT8001 is the Cys-linker-payload containing product. No free payload is observed. This compares favorably with T-DM1 where free DM1, T-DM1's payload, is one of the major catabolites. In a multiple dose toxicity study, BAT8001 had a NOAEL of 15 mg/kg versus 10 mg/kg for T-DM1. BAT8001 exhibits similar potency to T-DM1 on inhibiting HER2-positive cell proliferation and tumor growth, yet demonstrates better multiple dose toxicity than T-DM1. The improved toxicity profile of BAT8001 suggests that the novel noncleavable linker utilized in BAT8001 is more stable than the linker utilized in T-DM1. BAT8001 is very efficacious in cell-line xenograft models of breast cancer. The preclinical profile of BAT8001 warrants further development for the treatment of breast cancer and other HER2-positive cancers. Citation Format: Tang W, Deng X, Ou Z, Gan J, Dong Q, Tan B, Lu L, Chen B, Bao C, Li S, Thomas B, Yu J-C. BAT8001, a potent anti-HER2 antibody-drug conjugate with a novel stable linker for the treatment of HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-39.

Abstract P6-20-17: Targeting SHP2 for the treatment of HER2-positive breast cancer

Abstract Approximately 20% of breast cancer (BC) is caused by overexpression of the human epidermal growth factor receptor 2 (HER2). As a result, several antibody-based and small molecule-based anti-HER2 therapies have been developed. These drugs have benefited BC patients by improving overall survival and quality of life. However, development of resistance and disease recurrence have been the major clinical challenges. One way to overcome these clinical problems is to develop alternative therapeutic strategies. Multiple lines of evidence show that targeting the Src homology phosphotyrosyl phosphatase 2 (SHP2) in HER2-positive BC may prove beneficial both in treatment-naïve and anti-HER2 therapy-resistant forms of the disease. For instance, silencing SHP2 expression in HER2-positive breast cancer cells or conditional knockout in ErbB2 transgenic mice blocks HER2 overexpression and associated signaling, leading to loss of cell transformation and tumorigenesis. To test the clinical translational significance of SHP2 targeting, we have invented a specific small molecule SHP2 inhibitor named WGMDY (US 9,932,288) that has shown promising anti-cancer effects. The results obtained so far show that inhibition of SHP2 with WGMDY blocks HER2 expression, suppresses cell proliferation and anchorage independent growth, and induces regression of preformed xenograft tumors. These findings suggest that SHP2 might be an excellent drug target for HER2-positive BC and WGMDY has a promising potential to serve as a lead compound for developing anti-SHP2 drugs. Citation Format: Agazie Y, Hartman Z. Targeting SHP2 for the treatment of HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-17.

Abstract P6-09-12: Using multiphoton laser scanning microscopy to assess neoadjuvant therapy outcome in core needle biopsies: A novel methodology

Abstract Background: Over-expression of Human Epidermal Growth Factor receptor-2 (HER2) in breast cancer is associated with an aggressive clinical course and poor prognosis. Targeting HER2 over-expression has been shown to be a remarkably effective therapeutic modality in the metastatic, adjuvant and neoadjuvant setting and the pathologic response to neoadjuvant treatment in HER2-positive breast cancer has been shown to be an excellent surrogate for a good outcome. The stromal tumor microenvironment is implicated in fostering tumor growth, facilitating cell migration and ultimately resulting in metastatic disease. Specifically, the collagenous extracellular matrix, which includes fibrillar collagen, has been suggested to play a role in the migration of malignant breast epithelial cells within the surrounding stroma. We have developed a novel methodology which uses an intrinsic optical signature to quantitatively evaluate fibrillar collagen (Burke et al. BMC Cancer 15 (2015): 929). Here, we evaluate the ability of this quantitative methodology to predict the pathologic response after neoadjuvant HER2-targeted treatment as assessed by the Residual Cancer Burden score/class (RCB). This quantitative evaluation in pre-treatment biopsies is then correlated with the pathologic response to treatment in the post-therapy resection. Material and Methods: Clinical pathologic variables for 29 cases of HER2-positive breast cancer that had undergone neoadjuvant chemotherapy plus HER2-targeted therapy were retrieved from the medical record database at URMC, including the post-treatment RCB score and ER/PR/HER2 status. Second harmonic generation (SHG) is an intrinsic optical signal produced by fibrillar collagen. To quantify collagen microstructure in the pre-treatment core biopsy, we used SHG imaging to determine the average forward to backward-light scattering ratio (F/B). The F/B ratio is sensitive to structural properties of collagen fibers. Results: Logistic regression was used to assess the association between F/B and the binary response variable RCB class (0/1 or 2/3). A likelihood ratio test was used to calculate the p-value to test whether the regression coefficient for F/B was zero (i.e. no effect) in the tumor-stromal interface. The average F/B ratio at the leading edge of the tumor stratified by RCB class is shown in Table 1. When evaluated in the bulk of the tumor tissue, F/B was not correlated with RCB status; however, when evaluated at the leading edge of the tumor stromal interface, F/B was significantly correlated with RCB status (p=0.035). Table 1:RCB class and average F/BRCB class (n)Average F/B ± SEM0/1 (19)16.95 ± 1.062/3 (10)12.32 ± 1.84 Conclusions: We have previously shown that the measurement of F/B in the primary tumor after resection is an independent prognostic indicator of metastasis-free survival in breast cancer. Our results in the current study furthers these observations and suggests that the evaluations of the microstructure of collagen fibers by F/B measurement from the pre-treatment biopsy, specifically at the leading edge of the tumor-stroma interface, may be useful for predicting pathologic response to trastuzumab-based neoadjuvant therapy. Further studies in a larger patient cohort are warranted. Citation Format: Desa DE, Turner BM, Buscaglia B, Hill RL, Strawderman RL, Hicks DG, Brown EB. Using multiphoton laser scanning microscopy to assess neoadjuvant therapy outcome in core needle biopsies: A novel methodology [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-12.

Design, synthesis and biological study of potent and covalent HER-2 tyrosine kinase inhibitors with low cytotoxicity in vitro

The discovery and development of a novel HER-2 tyrosine kinase inhibitor for the treatment of HER2-positive breast cancer are presented in this article. EGFR family has been recognized as a crucial meditator in the cancer progression; HER-2 tyrosine kinase was one of the members among them. In the effort to explore potent HER-2 inhibitors, a novel series of 4-anilino-3-cyanoquinoline derivatives have been designed, synthesized and evaluated. Most compounds possessed modest proliferation inhibition on SK-BR-3 cell line and HER-2 kinase. Compound 16 appeared to be the most potent compound (HER-2 kinase IC50: 19.4 nM, SK-BR-3 IC50: 94 nM). In the experiment of cellular cytotoxicity assay, compound 16 shows a much lower cytotoxicity than neratinib on Beas-2b cell line (Human bronchial epithelial cells). In conclusion, compound 16 would be a promising lead compound for further anti-breast cancer drug discovery.

Docetaxel, trastuzumab, pertuzumab versus trastuzumab emtansine as neoadjuvant treatment of HER2-positive breast cancer: Results from the Swedish PREDIX HER2 trial identifying a new potential de-escalation standard?

501 Background: Neoadjuvant therapy produces high rates of pathological complete response (pCR) and is the standard of care in HER2 positive breast cancer; however, the optimal treatment regimen remains to be established. Methods: In this randomized phase II study patients ≥18 years with HER2 positive breast cancer > 20mm or verified lymph node metastases were randomized to 6 courses of docetaxel, trastuzumab and pertuzumab (DTP, group A) or trastuzumab emtansine (T-DM1, group B), q 21 days. The protocol allowed switch to the competing treatment upon lack of response or drug-related severe toxicity. Patients received postoperative epirubicin+cyclophosphamide, trastuzumab for a total of one year and endocrine therapy. Accrual was completed in October 2018 after randomization of 202 patients, data on pCR were available for 190 at the time for this abstract submission. Median age, 52 years (26-74), menopausal status, histological type and grade were well balanced between the treatment groups. 62.6% of the tumors were hormone receptor (HR) positive. Results: Primary endpoint was pathological objective response. 190 patients completed the protocol-specified preoperative treatment. pCR was achieved in 45.3% of patients, 46.4% in patients treated with DTP and 44.1% with T-DM1 (chi-sq., p = 0.75). In HR-positive tumors, pCR was obtained in 35.3% of patients, 35.9% in group A vs. 34.6% in group B (p = 0.87); in HR-negative tumors, the overall pCR rate was 62.0%, 66.7% in group A vs. 57.9% in group B (p = 0.45). Severe (grade 3/4) toxicity was reported at 68 occasions related to DTP, compared with 16 related to T-DM1, 26 vs. 3 caused by febrile neutropenia. Significantly better quality of life was reported by patients treated with T-DM1. Conclusions: Our data on TDM-1 demonstrates similar efficacy and less toxicity, in particular for patients with HER2 and HR positive cancers, being a potential new standard for neoadjuvant therapy. Clinical trial information: NCT02568839.

Health-related quality of life in the Swedish PREDIX HER2 trial, evaluating docetaxel, trastuzumab, pertuzumab versus trastuzumab emtansine as neoadjuvant treatment of HER2-positive breast cancer.

583 Background: Neoadjuvant therapy combining docetaxel, trastuzumab and pertuzumab (DTP) was compared to trastuzumab emtansine (T-DM1) in the randomized phase 2 PREDIX HER2 trial. Patients, ≥18 years with HER2 positive breast cancer, ≥20mm or with verified lymph node metastases, were randomized to six courses of DTP (Standard arm) or T-DM1 (Experimental arm). Primary endpoint was pathological objective response to primary medical therapy at post-treatment surgery. Health related quality of life (HRQoL) was a secondary outcome, and is of specific interest as there was no difference between the randomization groups regarding the main endpoint (results presented in a separate abstract sent to ASCO 2019, Bergh et al.). Methods: Of 202 randomized patients, 190 are available for evaluation at this point. HRQoL was measured, using EORTC QLQ-C30 + EORTC QLQ-BR23, at baseline before randomization and after six courses. Results: No differences between the randomization arms were found at baseline. Results after six courses, based on 163 patients (86%) and adjusted to baseline values, revealed statistical significant differences (p≤0.01), favoring the experimental T-DM1 arm on 7 out of 15 of the EORTC QLQ-C30 variables (Physical functioning, Role functioning, Social functioning, Global quality of Life, Fatigue, Dyspnea, and Diarrhea). For the breast cancer specific questionnaire (EORTC-BR23), the experimental arm scored statistically significantly better on 5 out of 7 subscales (Body image, Sexual functioning, Sexual enjoyment, Systemic therapy side effects and Upset by hair loss). All of the statistical significant differences were of moderate or large clinical significance (≥10 scale scores). No differences between the randomization arms were found for the remaining HRQoL variables. Conclusions: The experimental arm reported better HRQoL than the control arm after six courses. Trastuzumab emtansine may be a useful treatment alternative due to better HRQoL and lower toxicity. Clinical trial information: NCT02568839.

Linc01638 Promotes Tumorigenesis in HER2+ Breast Cancer.

BackgroundLong non‐coding RNAs play crucial roles in various biological activities and diseases. The role of long intergenic non‐coding RNA01638 (linc01638) in breast cancer, espe-cially in HER2-positive breast cancer, remains largely unknown.ObjectiveTo investigate the effect of linc01638 on tumorigenesis in HER2-positive breast cancer.MethodsWe first used qRT-PCR to detect linc01638 expression in HER2-positive breast cancer cells and tissues. Then we analyzed the effects of linc01638 expression in HER2-positive breast cancer cells through cell apoptosis assay, cell proliferation assay, colony formation assay, and cell invasion assay. We conducted mouse xenograft model to further confirm the role of linc01638 in HER2-positive breast cancer. Moreover, we used Western blot and IHC analysis to access the effect of linc01638 on DNMTs, BRCA1 and PTEN expressions in transplanted tumors.ResultsLinc01638 was found to be remarkably overexpressed in HER2-positive breast cancer cells and tissues. Suppression of linc01638 enhanced cell apoptosis, as well as inhibited the growth and in-vasiveness of HER2-positive breast cancer cells in vitro and tumor progression and metastasis in vivo. Furthermore, inhibition of linc01638 by shRNA attenuated expression of DNMT1, DNMT3a, and DNMT3b, and promoted expression of BRCA1 and PTEN in HER2-positive breast cancer cells and mouse xenograft models.ConclusionLinc01638 might be a promising biomarker and therapeutic target for treatment of HER2-positive breast cancer.

Nine weeks versus 1 year adjuvant trastuzumab in combination with chemotherapy: final results of the phase III randomized Short-HER study

BackgroundChemotherapy plus 1-year trastuzumab is the standard adjuvant treatment of HER2-positive breast cancer. The efficacy of less extended trastuzumab exposure is under investigation. The short-HER study was aimed to assess the non-inferiority of 9 weeks versus 1 year of adjuvant trastuzumab combined with chemotherapy. Patients and methodsHER2-positive breast cancer patients with node-positive or, if node negative, with at least one risk factor (pT>2 cm, G3, lympho-vascular invasion, Ki-67 > 20%, age ≤35 years, or hormone receptor negativity) were randomly assigned to receive sequential anthracycline–taxane combinations plus 1-year trastuzumab (arm A, long) or plus 9 weeks trastuzumab (arm B, short). This study was designed as a non-inferiority trial with disease-free survival (DFS) as primary end point. A DFS hazard ratio (HR) <1.29 was chosen as the non-inferiority margin. Analyses according to the frequentist and Bayesian approach were planned. Secondary end points included 2-year failure rate and cardiac safety. ResultsA total of 1254 patients from 82 centers were randomized (arm A, long: n = 627; arm B, short: n = 626). Five-year DFS is 88% in the long and 85% in the short arm. The HR is 1.13 (90% CI 0.89–1.42), with the upper limit of the CI crossing the non-inferiority margin. According to the Bayesian analysis, the probability that the short arm is non-inferior to the long one is 80%. The 5-year overall survival (OS) is 95.2% in the long and 95.0% in the short arm (HR 1.07, 90% CI 0.74–1.56). Cardiac events are significantly lower in the short arm (risk-ratio 0.33, 95% CI 0.22–0.50, P < 0.0001). ConclusionsThis study failed to show the non-inferiority of a shorter trastuzumab administration. One-year trastuzumab remains the standard. However, a 9-week administration decreases the risk of severe cardiac toxicity and can be an option for patients with cardiac events during treatment and for those with a low risk of relapse. Trial RegistrationEUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Use of data-mining to support real-world cost analyses: An example using HER2-positive breast cancer in Iran.

IntroductionPatient registries play an important role in obtaining real-world evidence of the cost-effectiveness of treatments. However, their implementation is costly and sometimes infeasible in many middle-income countries (MICs). We explored the combination of data-mining and a large claims database to estimate the direct healthcare costs of HER2-positive breast cancer (BC) treatment in Iran and the fraction of total costs from trastuzumab use.MethodWe performed a retrospective analysis of claims data from the Iran Social Security Organization, a health insurer which covers approximately 50%(~40 million) of the Iranian population, in the period of 21/03/2011-20/03/2014. A data-mining algorithm using R software and validated using patient dossiers in the Cancer Research Center identified 1295 patients and divided them into the three main HER2-positive breast cancer stages (early, loco-regional and advanced). A payer perspective was used to calculate the absolute and relative direct costs of healthcare services associated with the treatment of HER2-positive breast cancer in the public and private healthcare systems.ResultsThe number of women totaled 802 (early), 125 (loco-regional) and 218 (advanced). The mean age[SD] was 45[10], 46[10] and 48[10] years, respectively, while mean follow-up in all stages was approximately one year. Average costs of direct healthcare care in early, loco-regional and advanced stages were €11,796 (95%CI: €9,356-€12,498), €8,253 (95%CI: €6,843-€10,002), and €17,742 (95%CI: €15,720-€19,505), respectively. Trastuzumab accounted for the largest share of total costs in all three stages (range: 53–76%).ConclusionWherever comprehensive patient registries are infeasible or costly, real-world costs can be estimated through claims databases and data-mining strategies. Using this method, real-world costs have been estimated in Iran. The stage-specific cost estimates derived from this study can be used to perform real-world cost-effectiveness analyses of therapies for HER2-positive BC and support healthcare financing decisions.

MicroRNA-21 as a predictor and prognostic factor for trastuzumab therapy in human epidermal growth factor receptor 2-positive metastatic breast cancer.

Breast cancer is the second most common cancer diagnosed worldwide. Human epidermal growth factor receptor 2 (HER2)-positive breast cancer represents about 20% to 30% of all breast cancers. Trastuzumab is used in the treatment of HER2-positive breast cancer. MicroRNA-21 (miR-21) is an oncomiR that acts by inhibiting many tumor-suppressor genes. We analyzed the relative expression levels of serum miR-21 in 20 HER2-positive metastatic breast cancer patients before and after 3 months of treatment with trastuzumab. miR-21 levels decreased with a high significant difference after trastuzumab therapy (P = 0.001). Although miR-21 expression levels were lower in responders than in nonresponders, the difference was not statistically significant ( P = 0.6). Our results demonstrated a significant negative correlation between its basal expression, expression levels after treatment, and time to progression ( P = 0.03 and 0.01, respectively). These results make miR-21 a potential prognostic factor for HER2-positive metastatic breast cancer patients. Additionally, it can be an interesting potential target in therapy using antisense oligonucleotides for miR-21.

Mechanisms Underlying the Action and Synergism of Trastuzumab and Pertuzumab in Targeting HER2-Positive Breast Cancer.

Human epidermal growth factor receptor (HER) 2 (HER2) is overexpressed in 20–30% of breast cancers. HER2 is a preferred target for treating HER2-positive breast cancer. Trastuzumab and pertuzumab are two HER2-targeted monoclonal antibodies approved by the Food and Drug Administration (FDA) to use as adjuvant therapy in combination with docetaxel to treat metastatic HER2-positive breast cancer. Adding the monoclonal antibodies to treatment regimen has changed the paradigm for treatment of HER2-positive breast cancer. Despite improving outcomes, the percentage of the patients who benefit from the treatment is still low. Continued research and development of novel agents and strategies of drug combinations is needed. A thorough understanding of the molecular mechanisms underlying the action and synergism of trastuzumab and pertuzumab is essential for moving forward to achieve high efficacy in treating HER2-positive breast cancer. This review examined and analyzed findings and hypotheses regarding the action and synergism of trastuzumab and pertuzumab and proposed a model of synergism based on available information.

Optimal duration of adjuvant trastuzumab in treatment of early breast cancer: a meta-analysis of randomized controlled trials.

One year of adjuvant trastuzumab, chosen empirically, improves survival of women with early-stage, Human Epidermal Growth Factor Receptor 2 (HER2) positive breast cancer. Two years of trastuzumab does not improve efficacy but increases cost, inconvenience, and adverse effects. We aimed to evaluate if less than 1year of adjuvant trastuzumab retained efficacy while reducing toxicities and cost. We performed a pooled analyses of efficacy and toxicity from Randomized Controlled Trials (RCTs) comparing 1year of trastuzumab to shorter durations in adjuvant treatment of HER2-positive breast cancer. Hazard Ratios (HR) for Overall Survival (OS) and Disease-Free Survival (DFS), and Odds Ratios (OR) for cardiac events with respective 95% Confidence Intervals (CI) were weighted using generic inverse variance approach and pooled in meta-analyses using random effects models with RevMan 5.3 software. Sub-group analyses of outcomes based on Estrogen Receptor (ER) and nodal status were performed. Five RCTs involving approximately 12,000 patients qualified-three assessing 6months and two assessing 9weeks of trastuzumab compared to 1year. All RCTs were designed to test non-inferiority of the shorter treatment. One year of trastuzumabresulted into better OS (pooled HR 1.23, 95% CI 1.07-1.42) and DFS (pooled HR 1.21, 95% CI 1.09-1.36) in overall population, but the benefit of longer treatment was statisticallyinsignificant in node negative (HR 1. 20, p = 0.11), and ER positive disease (HR 1.15, p = 0.09). Odds ratio for cardiac events was significantly higher with the longer duration (OR 2.48, p < 0.001). One year of trastuzumab for adjuvant treatment of breast cancer improves outcomes compared to shorter treatments in overall population. Cardiotoxicity is increased with the longer treatment.

Androgen receptor expression inversely correlates with immune cell infiltration in human epidermal growth factor receptor 2–positive breast cancer

IntroductionAlthough targeting human epidermal growth factor receptor 2 (HER2) is a meaningful treatment in HER2-positive breast cancer, ultimately resistance develops. Androgen receptor (AR) expression and immune cell infiltration are thought to be involved in trastuzumab response and may, therefore, be of interest as additional targets for therapy in HER2-positive breast cancer. AimTo improve insights into the presence among AR expression, immune cell infiltration and HER2, we analysed HER2-positive breast tumours. MethodsPrimary tumours of 221 patients treated with trastuzumab for metastatic disease were selected. HER2 status was centrally confirmed. AR, T-cells (CD3 and CD8), programmed cell death protein 1 (PD-1) and PD-1 ligand 1 immunohistochemical staining and M2 tumour-associated macrophages (TAMs; CD68 and CD163) immunofluorescence were performed. Tumour-infiltrating lymphocytes were evaluated by haematoxylin and eosin staining. ResultsSufficient tumour material was available for 150 patients. Oestrogen receptor was expressed in 51.3% of the tumours and AR in 81.3% of the tumours. AR expression was inversely correlated with M2 TAM (Pearson's r = −0.361, P < 0.001), CD3+ (r = −0.199, P < 0.030) and CD8+ (r = −0.212, P < 0.021) T-cell infiltration. Clustering analysis showed high immune cell infiltration in AR low-expressing tumours, and low immune cell infiltration in AR-high expressing tumours. ConclusionAR expression inversely correlates with immune cell infiltration in HER2-positive breast cancer.

Neoadjuvant treatment of HER2-positive breast cancer – pathological complete response (pCR) as a surrogate of long term outcomes in the context of regulatory guidelines and reimbursement recommendations.

Background: The vast heterogeneity of breast cancer (BC) patients, together with relatively long survival in the early stages of the disease, leads to methodological issues in designing clinical trials, particularly in case of therapies targeted for narrow patients subsets. That situation led to the need and search for early, reliable predictors of long-term outcomes.However, in countries adopting HTA methodology to reimbursement decisions non-final (“surrogate”) endpoints may not be accepted as a measure of clinical benefit. Methods: We searched PubMed and EMBASE for meta-analyses investigating association of pathologic complete response to BC neoadjuvant therapy with longer-term clinical outcomes. To be eligible analyses had to pool primary studies identified in a systematic manner. The results of the included studies were discussed in the context of current regulatory and reimbursement recommendations. Results: The 4 included meta-analyses varied in methodological approaches, eligibility criteria and number of included patients. Three of them assessed predictive value of pCR in overall non-metastatic BC population and two – in HER2-positive subgroup. The existing differences in conclusions are consistent with the variability in methodological assumptions. Conclusion: Significant heterogeneity of BC population and low number of studies showing substantial treatment effect on pCR could bias the results of “trial-level” analyses. In contrast, studies consistently show significant patient-level association of pCR with clinical outcomes, particularly strong for aggressive tumour subtypes. The existing EMA and FDA guidelines show how to make use of the existing evidence, in spite of its limitations, in a pursuit of satisfying the unmet medical needs.