Neratinib, an irreversible ErbB receptor tyrosine kinase inhibitor, in patients with advanced ErbB2-positive breast cancer

Modelling hypersensitivity to trastuzumab defines biomarkers of response in HER2 positive breast cancer

BACKGROUND

Trastuzumab-based therapies are the therapeutic option for HER2 positive (HER2+) breast cancer. HER2 amplification is the only biomarker validated for trastuzumab-based therapies. However, a proportion of tumors become refractory during treatment course. For this reason, the finding of new biomarkers beyond HER2 overexpression to identify patients who would benefit most from trastuzumab regimens is of outstanding importance.

METHODS

Models of trastuzumab-resistant or hypersensitive cells were generated by exposure to trastuzumab. Cell surface, total HER2, and analyses of proteins involved in cell cycle or apoptosis were analyzed by western blotting. Cell proliferation was analyzed by cell counting, cell cycle and apoptosis was evaluated by FACS. Transcriptomic characterization of the cellular models was performed using bioinformatic online tools, and clinico-genomic analyses were performed using the PAMELA clinical trial data.

RESULTS

Besides differing in sensitivities to trastuzumab, the different cellular models also showed distinct response to other anti-HER2 drugs (lapatinib, neratinib, pertuzumab and T-DM1) used in the clinic. That differential effect was not due to changes in cell surface, total or activated HER2. Trastuzumab caused important induction of cell death in hypersensitive cells but not in parental or resistant cells. Transcriptomic analyses of these cellular models together with querying of online databases allowed the identification of individual genes and gene signatures that predicted prognosis and trastuzumab response in HER2+ breast cancer patients.

CONCLUSION

The identification of trastuzumab response biomarkers may be used to select patients particularly sensitive to facilitate the use of trastuzumab-based therapies and refine follow-up guidelines in patients with HER2+ tumors.

Neu Perspectives, Therapies, and Challenges for Metastatic HER2-Positive Breast Cancer

Even though gene amplification or protein overexpression occurs in approximately one-fifth of all breast cancers, the discovery of HER2 has, nevertheless, had profound implications for the disease. Indeed, the characterization of the receptor resulted in a number of significant advances. Structurally, unique features provided avenues for the development of numerous compounds with target-specificity; molecularly, biological constructs revealed a highly complex, internal signal transduction pathway with regulatory effects on tumor proliferation, survival, and perhaps, even resistance; and clinically, disease outcomes manifested its predictive and prognostic value. Yet despite the receptor’s utility, the beneficial effects are diminished by tumor recurrence after neo- or adjuvant therapy as well as losses resulting from the inability to cure patients with metastatic disease. What these observations suggest is that while tumor response may be partially linked to uncoupling cell surface message reception and nuclear gene expression, as well as recruitment of the innate immune system, disease progression and/or resistance may involve a reprogrammable signaling mainframe that elicits alternative growth and survival signals. This review attempts to meld current perceptions related to HER2-positive metastatic breast cancer with particular attention to current biological insights and therapeutic challenges.

Targeting HER2 in Breast Cancer: Latest Developments on Treatment Sequencing and the Introduction of Biosimilars

Approximately 20% of all breast cancers overexpress the human epidermal growth factor receptor 2 (HER2). Targeting breast cancer through this vital oncogenic protein has been a major step towards improved patient outcomes. Today, several anti-HER2 agents are in clinical use including: the monoclonal antibodies trastuzumab and pertuzumab; the small molecule inhibitors lapatinib, neratinib, and tucatinib; and the antibody-drug conjugates ado-trastuzumab emtansine and trastuzumab deruxtecan, in some jurisdictions. In addition, several trastuzumab biosimilars have recently been granted regulatory approval in North America and the EU, and are enhancing patient access to HER2-directed therapy. The various agents differ greatly in their side-effect profiles and approved indications, from neoadjuvant and adjuvant use in early disease, to first- and later-line use in metastatic disease. This review discusses the current treatment recommendations for the use of anti-HER2 agents alone and in combination, examines the latest advances in HER2-targeted drugs and how they may be best applied in clinical practice, and provides guidance on optimal sequencing of the growing array of therapeutic options for HER2-positive breast cancer.

The Clinical Efficacy and Safety of Neratinib in Combination with Capecitabine for the Treatment of Adult Patients with Advanced or Metastatic HER2-Positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) positive cancers account for 15–20% of all breast tumors. Several drugs have been approved in the metastatic setting, including monoclonal antibodies, tyrosine kinase inhibitors (TKI) and, more recently, antibody-drug conjugates. Neratinib is a pan-HER, irreversible TKI with potent preclinical activity against trastuzumab-resistant breast cancer models. Based on Phase I and II clinical trials, the combination of neratinib plus capecitabine was compared to lapatinib and capecitabine, an established regimen for trastuzumab-resistant disease, in the randomized, Phase III NALA trial. In this trial, neratinib yielded increased progression-free survival, response duration and a benefit in time to intervention for CNS progression. However, there was no overall survival benefit, no increase in overall response rate and no improvement in QoL. The most frequent adverse event in the neratinib arm was diarrhea, which was manageable with prophylactic treatment with loperamide. Conclusion: Neratinib is a valuable addition to the therapeutic armamentarium to treat metastatic, HER2-positive breast cancer. The current positioning of the combination of neratinib and capecitabine based on the results of the NALA trial needs to consider the rapidly evolving scenario due to the recent introduction of new drugs, like the pure-HER2 TKI tucatinib and the antibody drug-conjugate trastuzumab-deruxtecan.

Targeting mTOR and Glycolysis in HER2-Positive Breast Cancer

Up to one third of all breast cancers are classified as the aggressive HER2-positive subtype, which is associated with a higher risk of recurrence compared to HER2-negative breast cancers. The HER2 hyperactivity associated with this subtype drives tumor growth by up-regulation of mechanistic target of rapamycin (mTOR) pathway activity and a metabolic shift to glycolysis. Although inhibitors targeting the HER2 receptor have been successful in treating HER2-positive breast cancer, anti-HER2 therapy is associated with a high risk of recurrence and drug resistance due to stimulation of the PI3K-Akt-mTOR signaling pathway and glycolysis. Combination therapies against HER2 with inhibition of mTOR improve clinical outcomes compared to HER2 inhibition alone. Here, we review the role of the HER2 receptor, mTOR pathway, and glycolysis in HER2-positive breast cancer, along with signaling mechanisms and the efficacy of treatment strategies of HER2-positive breast cancer.

Phase II study of neratinib in older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer

OBJECTIVE

The tolerability and efficacy of targeted therapy in older adults with cancer has not been adequately studied. Neratinib is a novel HER1, HER2, HER4 tyrosine kinase inhibitor that has recently been granted FDA approval for treatment of breast cancer. The major toxicity of neratinib is diarrhea, which affects up to 90% of patients. This phase II trial evaluates the safety and tolerability of neratinib in adults ≥60.

METHODS

Patients aged 60 or older with histologically proven metastatic breast cancer and HER2 amplification (defined by ASCO/CAP guideline) or HER2/HER3 activating mutation were enrolled to receive neratinib at 240 mg daily in 28-day cycles. The association between tolerability, defined as dose reduction and number of completed courses, and log2 Cancer and Aging Research Group (CARG) toxicity risk score was assessed using a Student's t-test and linear regression, respectively. Response rate, progression free survival, and overall survival were also evaluated.

RESULTS

25 patients were enrolled with median age of 66 (range 60-79). Seventy-six percent of patients were white, 16% Asian, and 8% African-American. Seventy-six percent were patients with hormone receptor (HR) positive metastatic breast cancer (MBC) and 24% were patients with HR negative MBC. Median number of prior lines of metastatic therapy were 3 (range 0-11). 20/25 (80%) had worst grade toxicities ≥2. A total of 9/25 (36%) had grade 3 toxicities including 5/20 (20%) diarrhea, 2/20 (8%) vomiting, and 2/20 (8%) abdominal pain. There were no grade 4 or 5 toxicities. A total of 9/25 (36%) had dose reduction, and 2/25 (8%) discontinued therapy due to toxicity. The association between dose reductions and CARG toxicity score reached borderline statistical significance suggesting a trend with participants with higher CARG toxicity risk scores being more likely to require a dose modification (p = 0.054). 1/25 (4%) had a partial response, 11/25 (44%) had stable disease, 12/25 (48%) had progression of disease, and 1/25 (4%) was not assessed. Median progression free survival (PFS) was 2.6 months (95% CI [2.56-5.26]), and median overall survival (OS) was 17.4 months (95% CI [10.3, NA]).

CONCLUSIONS

Neratinib was safe in this population of older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer (BC). Higher CARG toxicity risk score may be associated with greater need for dose adjustments. Future studies are needed to confirm this finding.

Treating Advanced Unresectable or Metastatic HER2-Positive Breast Cancer: A Spotlight on Tucatinib

The management of HER2 positive breast cancer has been transformed by the development of targeted therapies. Dual blockade with the monoclonal antibodies, trastuzumab and pertuzumab, added to first-line taxane chemotherapy and second-line therapy with the antibody-drug conjugate, T-DM1, are internationally agreed standards of care for advanced HER2 positive breast cancer, where available. However, until recently, options for patients for third-line therapy and beyond were of modest efficacy or limited by toxicity. In 2019, the results of trials of two exciting new agents for this space were presented. A third-generation HER2 tyrosine kinase inhibitor, tucatinib, combines the efficacy of the second-generation drug, neratinib, with a more manageable toxicity profile and has become a new standard of care after T-DM1, in combination with capecitabine and trastuzumab. The antibody-drug conjugate, trastuzumab deruxtecan, demonstrated remarkable efficacy in heavily pre-treated patients and received accelerated approval in the United States, whilst confirmatory Phase 3 trials are completed. This review will discuss the available data for the post-T-DM1 setting, focusing on tyrosine kinase inhibitors including tucatinib.

Epidermal growth factor receptor inhibitor-induced diarrhea: clinical incidence, toxicological mechanism, and management

The epidermal growth factor receptor (EGFR) family is a class of receptor tyrosine kinase playing a central role in carcinogenesis and cancer progression. The members of this family, particularly EGFR and human epidermal growth factor receptor 2 (HER2), are the most extensively studied drug targets for malignancy. Today, numerous tyrosine kinase inhibitors targeting EGFR family have been developed to combat non-small-cell lung cancer and breast cancer. However, severe gastrointestinal (GI) toxicity leading to dose reduction and treatment discontinuation hampers the therapeutic outcome of EGFR inhibitors. Diarrhea is one of the most frequent GI side effects, especially when it comes to second-generation EGFR inhibitors. Enterocytes apoptosis and increased inflammation accompany with many oral EGFR inhibitors. Loperamide and budesonide are the first-line treatment to manage such adverse effects. However, current prophylaxis and management are all empirical interventions to relieve the symptom. They do not specifically target the toxicological mechanism of EGFR inhibitors. Hereby, those anti-diarrhea agents do not work well when used in cancer patients experiencing EGFR inhibitor-induced diarrhea. On the other hand, the toxicological mechanism of EGFR inhibitor-induced diarrhea is poorly understood. Thus, determining the mechanism behind such diarrhea is urgently in need for developing genuinely effective anti-diarrhea agents. This review aims to call attention to EGFR inhibitor-induced diarrhea, a highly occurring and devastating cancer drug toxicity.

The role of HER2 and HER3 in HER2-amplified cancers beyond breast cancers

HER2 and HER3 play key driving functions in the pathophysiology of HER2-amplified breast cancers, but this function is less well characterized in other cancers driven by HER2 amplification. This study aimed to explore the role of HER2 and HER3 signaling in other types of HER2-amplified cancer. The expression and signaling activity of HER2, HER3, and downstream pathway proteins were studied in cell panels representing HER2-amplified cancers of the breast, bladder, colon and rectal, stomach, esophagus, lung, tongue, and endometrium along with controls lacking HER2 amplification. We report that HER2-amplified cancers are addicted to HER2 across different cancer types and the depth of addiction is best linked with the expression level of HER2, but not with HER3 expression. We report that the expression and constitutive phosphorylation of HER3 are ubiquitous in HER2-amplified breast cancer cell lines, but much more variable in HER2-amplified cancer cells from other tissues. We observed the lapatinib-induced compensatory upregulation of HER3 signaling in many types of HER2-amplified cancers, although with much variability. We find that HER3 expression is essential for in vivo tumorigenic growth in some HER2-amplified tumors but not others. Importantly HER3 expression level does not correlate well with its functional importance. More biomarkers will be needed to guide the optimal use of HER3 inhibitors in HER2-amplified cancers from non-breast origin. Unlike oncogenes activated through mutational events, the activation of HER2 through overexpression represents a gradient of activities and depth of addiction and the response to inhibitors follows a similar gradient.

Cardiovascular toxicity of breast cancer treatment: an update

Novel chemotherapeutic agents have marked a new era in oncology during the past decade, prolonging significantly the overall survival of breast cancer patients. Nevertheless, contemporary antineoplastic treatments can frequently cause adverse cardiovascular side effects. Common manifestations of chemotherapy-induced cardiotoxicity include cardiomyopathy, ischemia, conduction disturbances, hypertension and thromboembolic events, while the type of the treatment regimen administered crucially determines clinical outcome. The aim of this literature review is to analyze the incidence and the underlying mechanisms of cardiovascular toxicity caused by agents approved for breast cancer, as well as to describe ways of monitoring and treating the cardiotoxic effects in breast cancer patients. Moreover, our work intends to provide an easy-to-grasp synopsis of recent and clinically meaningful advances in the field.

Recent Progress in the Development of Quinoline Derivatives for the Exploitation of Anti-Cancer Agents

BACKGROUND

Along with the progress in medicine and therapies, the exploitation of anti-cancer agents focused more on the vital signaling pathways and key biological macromolecules. With rational design and advanced synthesis, quinoline derivatives have been utilized frequently in medicinal chemistry, especially in developing anti-cancer drugs or candidates.

METHODS

Using DOI searching, articles published before 2020 all over the world have been reviewed as comprehensively as possible.

RESULTS

In this review, we selected the representative quinoline derivate drugs in market or clinical trials, classified them into five major categories with detailed targets according to their main mechanisms, discussed the relationship within the same mechanism, and generated a summative discussion with prospective expectations. For each mechanism, the introduction of the target was presented, with the typical examples of quinoline derivate drugs.

CONCLUSION

This review has highlighted the quinoline drugs or candidates, suited them into corresponding targets in their pathways, summarized and discussed. We hope that this review may help the researchers who are interested in discovering quinoline derivate anti-cancer agents obtain considerable understanding of this specific topic. Through the flourishing period and the vigorous strategies in clinical trials, quinoline drugs would be potential but facing new challenges in the future.

Breast Cancer Therapeutics and Biomarkers: Past, Present, and Future Approaches

Breast cancer (BC) is the leading cause of cancer death in women and the second-most common cancer. An estimated 281 550 new cases of invasive BC will be diagnosed in women in the United States, and about 43 600 will die during 2021. Continual research has shed light on all disease areas, including tumor classification and biomarkers for diagnosis/prognosis. As research investigations evolve, new classes of drugs are emerging with potential benefits in BC treatment that are covered in this manuscript. The initial sections present updated classification and terminology used for diagnosis and prognosis, which leads to the following topics, discussing the past and present treatments available for BC. Our review will generate interest in exploring the complexity of the cell cycle and its association with cancer biology as part of the plethora of target factors toward developing newer drugs and effective therapeutic management of BC.

Breast Cancer Brain Metastasis-Overview of Disease State, Treatment Options and Future Perspectives

Simple Summary

In this review, we present the latest information on the pathophysiology, diagnosis, and local and systemic treatment of brain metastases from breast cancer, with a focus on recent publications. Improving the local treatment and subtype-specific systemic therapies through advancements in basic and translational research will contribute to better clinical outcomes for patients with breast cancer brain metastasis.

Abstract

Breast cancer is the second most common origin of brain metastasis after lung cancer. Brain metastasis in breast cancer is commonly found in patients with advanced course disease and has a poor prognosis because the blood–brain barrier is thought to be a major obstacle to the delivery of many drugs in the central nervous system. Therefore, local treatments including surgery, stereotactic radiation therapy, and whole-brain radiation therapy are currently considered the gold standard treatments. Meanwhile, new targeted therapies based on subtype have recently been developed. Some drugs can exceed the blood–brain barrier and enter the central nervous system. New technology for early detection and personalized medicine for metastasis are warranted. In this review, we summarize the historical overview of treatment with a focus on local treatment, the latest drug treatment strategies, and future perspectives using novel therapeutic agents for breast cancer patients with brain metastasis, including ongoing clinical trials.

Real-world evidence from a University Hospital system regarding the uptake of adjuvant pertuzumab and/or neratinib before and after their FDA approval

Purpose

Adjuvant pertuzumab and neratinib are independently FDA-approved for treatment of early-stage HER2-positive breast cancer in combination with or following trastuzumab for one year, respectively. Both agents reduce the risk of recurrence; however, the absolute benefit is modest for many patients with added risk of adverse effects. The purpose of this study was to evaluate the clinical use of adjuvant pertuzumab and neratinib in patients with early-stage HER2-positive breast cancer.

Methods

Patients diagnosed with stage I–III HER2-positive breast cancer treated with trastuzumab at four University of Colorado Health hospitals between July 2016 and April 2019 were identified. Patient demographics, cancer stage, treatment, and administration of pertuzumab and/or neratinib were obtained.

Results

We identified a total of 350 patients who received adjuvant trastuzumab for stage I–III HER2-positive breast cancer; 253 (73.1%) had tumors that were ≥ T2 or node-positive disease. The rate of adjuvant pertuzumab use increased following FDA approval; pertuzumab was administered to the majority of patients with node-positive HER2-positive breast cancer. The use of adjuvant pertuzumab was associated with younger age, premenopausal status, and node-positive disease. Rates of administration of adjuvant neratinib were lower, with only 15.2% of patients receiving this therapy within 3 months of completing adjuvant trastuzumab.

Conclusion

In our cohort of patients treated within a diverse healthcare network, the majority of patients with node-positive HER2-positive breast cancer received adjuvant pertuzumab following FDA approval. The use of adjuvant neratinib was less common, potentially as a result of adverse effects, prolongation of therapy, previous administration of adjuvant pertuzumab, and modest benefit.

Influence of antioxidant flavonoids quercetin and rutin on the in-vitro binding of neratinib to human serum albumin

This study was designed to examine the interaction of neratinib (NRB) with human serum albumin (HSA) in presence of flavonoids quercetin and rutin. Both quercetin and rutin can compete with NRB to bind to HSA and displace NRB from its binding site. The interaction mechanism was studied with several spectroscopic techniques and molecular docking. Static fluorescence quenching mechanism was observed on interaction of HSA with NRB. van der Waals force and hydrogen bond were involved in the HSA-NRB interaction as per the results of thermodynamic parameters. Further, the conformational changes were observed in the HSA on its interaction with NRB. Interaction of NRB with HSA in presence of quercetin and rutin resulted in changes in the binding constants of HSA-NRB suggesting some impact on the binding of NRB in the presence of flavonoids.

Safety, tolerability, and pharmacokinetics of BAT8001 in patients with HER2-positive breast cancer: An open-label, dose-escalation, phase I study

BACKGROUND

The introductions of anti- human epidermal growth factor receptor-2 (HER2) agents have significantly improved the treatment outcome of patients with HER2-positive breast cancer. BAT8001 is a novel antibody-drug conjugate targeting human epidermal growth factor receptor-2 (HER2)-expressing cells composed of a trastuzumab biosimilar linked to the drug-linker Batansine. This dose-escalation, phase I study was designed to assess the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of BAT8001 in patients with HER2-positive locally advanced or metastatic breast cancer.

METHODS

This trial was conducted in subjects with histologically confirmed HER2-positive breast cancer (having evaluable lesions and an Eastern Cooperative Oncology Group performance status of 0 or 1) using a 3 + 3 design of escalating BAT8001 doses. Patients received BAT8001 intravenously in a 21-day cycle, with dose escalation in 5 cohorts: 1.2, 2.4, 3.6, 4.8, and 6.0 mg/kg. The primary objective was to evaluate the safety and tolerability of BAT8001. Preliminary activity of BAT8001 was also assessed as a secondary objective.

RESULTS

Between March 2017 to May 2018, 29 HER2-positive breast cancer patients were enrolled. The observed dose-limiting toxicities were grade 4 thrombocytopenia and grade 3 elevated transaminase. The maximum tolerated dose was determined to be 3.6 mg/kg. Grade 3 or greater adverse events (AEs) occurred in 14 (48.3%) of 29 patients, including thrombocytopenia in 12 (41.4%) patients, aspartate aminotransferase increased in 4 (13.8%) patients, γ-glutamyl transferase increased in 2 (6.9%) patients, alanine aminotransferase increased in 2 (6.9%) patients, diarrhea in 2 (6.9%) patients. Objective response was observed in 12 (41.4%; 95% confidence interval [CI] = 23.5%-61.1%) and disease control (including patients achieving objective response and stable disease) was observed in 24 (82.8%; 95% CI = 64.2%-94.2%) patients.

CONCLUSIONS

BAT8001 demonstrated favorable safety profiles, with promising anti-tumor activity in patients with HER2-positive locally advanced or metastatic breast cancer. BAT8001 has the potential to provide a new therapeutic option in patients with metastatic HER2-positive breast cancer.

Cardiotoxicity in HER2-positive breast cancer patients

Due to the recent advances in diagnosis and management of patients with HER2-positive breast cancer, especially through novel HER2-targeted agents, cardiotoxicity becomes an emerging problem. Although chemotherapy significantly increases survival, the risk of cardiovascular disease development is high and still underestimated and could imply treatment discontinuation. Frequently, due to lack of rigorous diagnosis strategies, cardiotoxicity assessment is delayed, and, moreover, the efficacy of current therapy options in restoring heart function is questionable. For a comprehensive risk assessment, it is vital to characterize the clinical spectrum of HER2-targeted agents and anthracyclines, as well as their pathogenic pathways involved in cardiotoxicity. Advanced cardiovascular multimodal imaging and circulating biomarkers plays primary roles in early assessing cardiotoxicity and also in guiding specific preventive measures. Even though the knowledge in this field is rapidly expanding, there are still questions that arise regarding the optimal approach in terms of timing and methods. The aim of the current review aims to providean overview of currently available data.

Melatonin potentiates the cytotoxic effect of Neratinib in HER2+ breast cancer through promoting endocytosis and lysosomal degradation of HER2

Complete blockade of the HER2 protein itself and HER signaling network is critical to achieving effective HER2-targeted therapies. Despite the success of HER2-targeted therapies, the diseases will relapse in a significant fraction of patients with HER2⁺ breast cancers. How to improve the therapeutic efficacy of existing HER2-targeted agents remains an unmet clinical need. Here, we uncover a role of Melatonin in diminishing HER2-mediated signaling by destruction of HER2 protein. Mechanistically, Melatonin treatment attenuated the protective effect of the HSP90 chaperone complex on its client protein HER2, triggering ubiquitylation and subsequent endocytic lysosomal degradation of HER2. The inhibitory effect of Melatonin on HER2 signaling substantially enhanced the cytotoxic effects of the pan-HER inhibitor Neratinib in HER2⁺ breast cancer cells. Lastly, we demonstrate that dual inhibition of HER2 by combined use of Melatonin and Neratinib effectively blocked the growth of HER2⁺ breast tumor xenografts in vivo. Our findings shed light on the potential use of Melatonin in a novel dual HER2 blockade strategy for HER2⁺ breast cancer treatment.

ERBB2b mRNA isoform encodes a nuclear variant of the ERBB2 oncogene in breast cancer

The presence of nuclear ERBB2 receptor-type tyrosine kinase is one of the causes of the resistance to membrane ERBB2-targeted therapy in breast cancers. It has been previously reported that this nuclear location arises through at least two different mechanisms: proteolytic shedding of the extracellular domain of the full-length receptor and translation of the messenger RNA (mRNA)-encoding ERBB2 from internal initiation codons. Here, we report a new mechanism and function where a significant portion of nuclear ERBB2 results from the translation of the variant ERBB2 mRNA under the transcriptional control of a distal promoter that is actively used in breast cancer cells. We show that both membrane ERBB2a and nuclear ERBB2b isoforms are prevalently expressed in breast cancer cell lines and carcinoma samples. The ERBB2b isoform, which is translated from mRNA variant 2, can directly translocate into the nucleus due to the lack of the signal peptide which is required for an intermediate membrane location. Small interfering RNA-mediated gene silencing showed that ERBB2b can repress ERBB2a expression, encoded by variant 1, whereas ERBB2a activates ERBB2b. Nuclear ERBB2 binding to its own promoter was revealed by chromatin immunoprecipitation assay. Altogether, our results provide new insights into the origin and function of nuclear ERBB2 where it can participate at the same time in a positive or a negative feedback autoregulatory loop, dependent on which of its promoters this bona fide transcription factor is acting. They also provide a new understanding for the resistance to therapies targeting the membrane-anchored ERBB2 in breast cancer.

SHP2 is a multifunctional therapeutic target in drug resistant metastatic breast cancer

Metastatic breast cancer (MBC) is an extremely recalcitrant disease capable of bypassing current targeted therapies via engagement of several growth promoting pathways. SH2 containing protein tyrosine phosphatase-2 (SHP2) is an oncogenic phosphatase known to facilitate growth and survival signaling downstream of numerous receptor inputs. Herein, we used inducible genetic depletion and two distinct pharmacological inhibitors to investigate the therapeutic potential of targeting SHP2 in MBC. Cells that acquired resistance to the ErbB kinase inhibitor, neratinib, displayed increased phosphorylation of SHP2 at the Y542 activation site. In addition, higher levels of SHP2 phosphorylation, but not expression, were associated with decreased survival of breast cancer patients. Pharmacological inhibition of SHP2 activity blocked ERK1/2 and AKT signaling generated from exogenous stimulation with FGF2, PDGF, and hGF and readily prevented MBC cell growth induced by these factors. SHP2 was also phosphorylated upon engagement of the extracellular matrix (ECM) via focal adhesion kinase. Consistent with the potential of SHP2-targeted compounds as therapeutic agents, the growth inhibitory property of SHP2 blockade was enhanced in ECM-rich 3D culture environments. In vivo blockade of SHP2 in the adjuvant setting decreased pulmonary metastasis and extended the survival of systemic tumor-bearing mice. Finally, inhibition of SHP2 in combination with FGFR-targeted kinase inhibitors synergistically blocked the growth of MBC cells. Overall, our findings support the conclusion that SHP2 constitutes a shared signaling node allowing MBC cells to simultaneously engage a diversity of growth and survival pathways, including those derived from the ECM.

Treatment Landscape for Patients with HER2-Positive Metastatic Breast Cancer: A Review on Emerging Treatment Options

The prognosis of HER2-positive metastatic breast cancer (MBC) has radically changed in recent years and continues to improve due to the broad application of effective therapies like monoclonal antibodies and small molecules targeting HER2. Persistent dependency of tumor cells on the oncogene HER2, on one hand, as well as low expression levels in healthy tissue, on the other hand, make this protein an ideal target for anti-cancer therapy. New HER2 targeting strategies including targeted delivery of cytotoxic drugs via HER2 receptor have been developed. Recently, the US Food and Drug Administration (FDA) approved three new drugs for the treatment of HER2-positive MBC: the antibody–drug conjugate trastuzumab deruxtecan and the two tyrosine kinase inhibitors neratinib and tucatinib. Here, we summarize recent publications and developments of novel anti-HER2 therapies like monoclonal antibodies with improved properties compared to trastuzumab and bispecific antibodies, which bind two different HER-epitopes or bring T cells closer to tumor cells. Furthermore, novel antibody-drug conjugates and small molecules against HER2 are discussed. These developments coupled with new combination strategies (eg, with CDK4/6 inhibitors or immunotherapy) will change the treatment landscape for patients with HER2-positive MBC very soon and will hopefully further improve clinical outcomes.

Beyond Chemotherapies: Recent Strategies in Breast Cancer Treatment

In 2018, about 2.1 million women have been diagnosed with breast cancer worldwide. Treatments include-among others-surgery, chemotherapy, radiotherapy, or endocrine therapy. The current policy of care tends rather at therapeutic de-escalation, and systemic treatment such as chemotherapies alone are not systematically considered as the best option anymore. With recent advances in the understanding of cancer biology, and as a complement to anatomic staging, some biological factors (assessed notably via gene-expression signatures) are taken into account to evaluate the benefit of a chemotherapy regimen. The first aim of this review will be to summarize when chemotherapies can be avoided or used only combined with other treatments. The second aim will focus on molecules that can be used instead of chemotherapeutic drugs or used in combination with chemotherapeutic drugs to improve treatment outcomes. These therapeutic molecules have emerged from the collaboration between fundamental and clinical research, and include molecules, such as tyrosine kinase inhibitors, CDK4/6 inhibitors, and monoclonal antibodies (such as anti-PD-L1). In the fight against cancer, new tools aiding decision making are of the utmost importance: gene-expression signatures have proven to be valuable in the clinic, notably, to know when chemotherapies can be avoided. When substitution treatments are also available, a big step can be made toward personalized medicine for the patient's benefit.

Neratinib plus capecitabine for the treatment of advanced HER2-positive breast cancer

INTRODUCTION

Several agents are being developed for advanced HER2-positive breast cancer, such as potent tyrosine kinase inhibitors (TKI) targeting ErbB family receptors, novel antibody-drug conjugates, higher affinity anti-HER2 antibodies, among others. Neratinib is an irreversible pan-HER (EGFR, ERBB2, and ERBB4) TKI being tested in early and advanced HER2-positive breast cancer. In the NALA trial, neratinib plus capecitabine led to increased PFS and time to intervention for central nervous system disease over the standard regimen of lapatinib plus capecitabine. The main adverse event in the neratinib arm was diarrhea, which mandates for prophylactic treatment with loperamide.

AREAS COVERED

In this review, we analyze and discuss preclinical and clinical data with neratinib plus capecitabine. We summarize efficacy and safety results from phase I/II and III trials, and discuss this regimen within the landscape of treatment for patients with HER2-positive metastatic breast cancer progressing after two lines of HER2-directed treatment.

EXPERT OPINION

Neratinib plus capecitabine is a valid treatment option for patients with advanced HER2-positive breast cancer, after progression to at least two anti-HER2-based regimens. Given the multiple options that are being developed in this context, efforts should be employed to establish strong predictive biomarkers of efficacy to each drug and combination.

Trastuzumab Targeted Neratinib Loaded Poly-Amidoamine Dendrimer Nanocapsules for Breast Cancer Therapy

Background

Human epidermal growth factor receptor2 (Her2) positive breast cancer represents 25% of breast cancer cases. Targeted therapy with Her2 monoclonal antibody, trastuzumab (TZ), represents the first-line treatment for this type of breast cancer. In addition, neratinib, an irreversible inhibitor of the HER-2 receptor tyrosine kinase, has recently been approved as adjuvant therapy to TZ. This study aims to formulate (TZ)-grafted dendrimers loaded with neratinib, allowing a dual treatment alongside reducing the associated resistance as well as targeted therapy.

Methods

TZ was conjugated on the surface of dendrimer using hetero-cross linker, MAL-PEG-NHS, and the zeta potential, and in vitro release of neratinib from dendrimers was characterized. Formulated dendrimers were also fluorescently conjugated with fluorescein isothiocyanate to visualize and quantify their SKBR-3 cellular uptake.

Results

The G4 PAMAM dendrimer showed successful encapsulation of neratinib and a sustained release profile. Comparative in vitro studies revealed that these TZ-targeted dendrimers loaded with neratinib were more selective and have higher antiproliferation activity against SKBR-3 cells compared to neratinib alone and neratinib loaded dendrimer.

Conclusion

In the current study, neratinib loaded in plain and trastuzumab-grafted dendrimer were successfully prepared. Enhanced cellular uptake of trastuzumab conjugated dendrimers was shown, together with a higher cytotoxic effect than plain neratinib dendrimers. These findings suggest the potential of TZ-conjugated dendrimers as targeting carrier for cytotoxic drugs, including neratinib.

Neratinib-Induced Duodenal Ulcer: A Case Report

We report a case of a 37-year-old woman who developed a duodenal ulcer while receiving adjuvant neratinib for HER2 positive breast cancer. The clinical course of abdominal pain was strongly correlated with the use of neratinib. An esophagogastroduodenoscopy (EGD) was performed and confirmed the diagnosis of a large duodenal ulcer. Neratinib was stopped, and the patient was treated with a proton pump inhibitor. Repeat EGD performed 3 months later showed complete resolution of the duodenal ulcer. Given this unexpected serious adverse event and only modest benefit of neratinib in the adjuvant setting, the decision was made to forgo further treatment with neratinib. Physicians should be aware of the gastrointestinal (GI) side effects associated with neratinib and recognize that peptic ulcer disease may be another GI toxicity associated with neratinib use.

New Therapeutics in HER2-Positive Advanced Breast Cancer: Towards a Change in Clinical Practices?pi

Over the last few decades, improved knowledge of oncogenic activation mechanisms of HER2 protein has led to the development of HER2 targeted therapies that are currently commonly used in HER2-positive advanced breast cancer, such as trastuzumab, lapatinib, pertuzumab, and ado-trastuzumab emtansine. The management of this breast cancer subgroup has thus been revolutionized and its prognosis has changed dramatically. Nevertheless, HER2-positive advanced breast cancer remains an incurable disease and resistance to conventional anti-HER2 drugs is almost unavoidable. Nowadays, biochemical and pharmaceutical advances are meeting the challenge of developing increasingly sophisticated therapies directed against HER2, including novel anti HER2 antibodies with increased affinity. New antibody-drug conjugates (ADC) with more advanced pharmacological properties, and dual targeting of epitopes via bispecific monoclonal antibodies are also emerging. In addition, more potent and more specific HER2 tyrosine kinase inhibitors have shown interesting outcomes and are under development. Finally, researchers' interest in tumor microenvironment, particularly tumor-infiltrating lymphocytes, and the major role that signaling pathways, such as the PI3K/AKT/mTOR pathway, play in the development of resistance to anti-HER2 therapies have spurred the development of clinical trials evaluating innovative combinations of anti-HER2 with PD-1/PDL-1, CDK4/6 and PI3K inhibitors. However, several questions remain unresolved, like the optimal management of HER2-positive/HR-positive advanced breast cancer and the identification of predictive biomarkers to better define populations that can benefit most from these new therapies and approaches.

Towards precision oncology for HER2 blockade in gastroesophageal adenocarcinoma

Gastroesophageal adenocarcinoma (GEA) represents a very heterogeneous disease and patients in advanced stages have a very poor prognosis. Although several molecular classifications have been proposed, precision medicine for HER2-amplified GEA patients still represents a challenge. Despite improvement in clinical outcomes obtained by adding trastuzumab to first-line platinum-based chemotherapy, no other anti-HER2 agents used first-line or beyond progression have demonstrated any benefit. Several factors contribute to this failure. Among them, variable HER2 amplification assessment, tumour heterogeneity, molecular mechanisms of resistance and microenvironmental factors could limit the effectiveness of anti-HER2 blockade. Identifying the factors responsible for both primary and acquired resistance is a priority for providing an improved, personalised approach. In this review, we examine current treatments for HER2-amplified GEA, their potential mechanisms of resistance and the ways to overcome them, investigating the most relevant translational studies with anti-HER2 agents in GEA, as well as novel agents under development in this field.

Neratinib for the treatment of early-stage, hormone receptor-positive, HER2-overexpressed breast cancer

HER2-positive breast cancer accounts for 18-20% of all breast cancers. Despite significant advances and the currently available adjuvant treatments for management of the disease, approximately 25% of HER2-positive early-stage breast cancer patients show relapse and die. Neratinib is an irreversible tyrosine kinase inhibitor. Multiple studies have reported its significant antitumor activity in metastatic HER2-positive breast cancer. It is administered orally and has also been tested in the adjuvant setting. In this article, we present a comprehensive review of the pharmacokinetics and pharmacodynamics of neratinib as well as its clinical efficacy, with an emphasis on early HER2-positive breast cancer and suggestions for future directions for neratinib research.

Effectiveness and Safety of Pyrotinib, and Association of Biomarker With Progression-Free Survival in Patients With HER2-Positive Metastatic Breast Cancer: A Real-World, Multicentre Analysis

Background: Pyrotinib, an irreversible pan-ERBB inhibitor, has shown promising antitumour activity, and acceptable tolerability. This research was conducted to evaluate the actual use and effectiveness of pyrotinib in China, therefore, contributed to solve the problem of real-world data scarcity. Methods: In this retrospective study, 168 patients who received pyrotinib treatment for HER2-positive metastatic breast cancer (MBC) in Hunan Province from June 2018 to August 2019 were included. Progression-free survival (PFS), tumor mutation burden (TMB), and drug-related adverse events (AEs) after pyrotinib administration were analyzed. Results: The median PFS (mPFS) time in the 168 participants was 8.07 months. The mPFS times in patients with pyrotinib in second-line therapy (n = 65) and third-or-higher-line therapy (n = 94) were 8.10 months and 7.60 months, respectively. Patients with brain metastases achieved 8.80 months mPFS time. In patients with pyrotinib in third-or-higher-line therapy, patients who had previously used lapatinib still got efficacy but showed a shorter mPFS time (6.43 months) than patients who had not (8.37 months). TMB was measured in 28 patients, K-M curve (P = 0.0024) and Multivariate Cox analysis (P = 0.0176) showed a significant negative association between TMB and PFS. Diarrhea occurred in 98.2% of participants (in any grade) and 19.6% in grade 3-4 AEs. Conclusion: Pyrotinib is highly beneficial to second-or-higher-line patients or HER2-positive MBC patients with brain metastases. Pyrotinib seems to be a feasible strategy both in combination of chemotherapeutic drugs or as a replacement of lapatinib if diseases progressed. TMB could be a potential predictor for evaluating pyrotinib's effectiveness in HER2-positive MBC.

Overcoming trastuzumab resistance in HER2-positive breast cancer using combination therapy

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) comprises around 20-30% of all BC subtypes and is correlated with poor prognosis. For many years, trastuzumab, a monoclonal antibody, has been used to inhibit the HER2 activity. Though, the main resistance to trastuzumab has challenged the use of this drug in the management of HER2-positive BC. Therefore, the determination of resistance mechanisms and the incorporation of new agents may lead to the development of a better blockade of the HER family receptor signaling. During the last few years, some therapeutic drugs have been developed for treating patients with trastuzumab-resistant HER2-positive BC that have more effective influences in the management of this condition. In this regard, the present study aimed at reviewing the mechanisms of trastuzumab resistance and the innovative therapies that have been investigated in trastuzumab-resistant HER2-positive BC subjects.

Lipid metabolic reprogramming as an emerging mechanism of resistance to kinase inhibitors in breast cancer

Breast cancer is one of the leading causes of death in women in the United States. In general, patients with breast cancer undergo surgical resection of the tumor and/or receive drug treatment to kill or suppress the growth of cancer cells. In this regard, small molecule kinase inhibitors serve as an important class of drugs used in clinical and research settings. However, the development of resistance to these compounds, in particular HER2 and CDK4/6 inhibitors, often limits durable clinical responses to therapy. Emerging evidence indicates that PI3K/AKT/mTOR pathway hyperactivation is one of the most prominent mechanisms of resistance to many small molecule inhibitors as it bypasses upstream growth factor receptor inhibition. Importantly, the PI3K/AKT/mTOR pathway also plays a pertinent role in regulating various aspects of cancer metabolism. Recent studies from our lab and others have demonstrated that altered lipid metabolism mediates the development of acquired drug resistance to HER2-targeted therapies in breast cancer, raising an interesting link between reprogrammed kinase signaling and lipid metabolism. It appears that, upon development of resistance to HER2 inhibitors, breast cancer cells rewire lipid metabolism to somehow circumvent the inhibition of kinase signaling. Here, we review various mechanisms of resistance observed for kinase inhibitors and discuss lipid metabolism as a potential therapeutic target to overcome acquired drug resistance.

Cardiotoxicity of HER2-targeted therapies

PURPOSE OF REVIEW

Cardiotoxicity is a well recognized adverse effect of human epidermal growth factor receptor 2 (HER2)-targeted therapies. The goal of this review is to highlight recent studies that have advanced our knowledge of the diagnosis, prevention, and management of cardiotoxicity associated with HER2-targeted agents.

RECENT FINDINGS

Several clinical risk factors for cardiotoxicity associated with HER2-targeted therapies have been identified including age, low-baseline left ventricular ejection fraction, and treatment with anthracyclines; however, these remain insufficient to identify all patients at risk for cardiotoxicity. Routine cardiac monitoring remains the standard for cardiotoxicity surveillance, although the optimal frequency and modality of monitoring remains uncertain. Global longitudinal strain, T1/T2 weighted CMR imaging protocols, and circulating biomarkers can detect early signs of cardiotoxicity, but studies are needed to investigate whether use of these markers in clinical practice improves patient outcomes. Cardioprotective medications (e.g. beta-blockers or ACE-inhibitors) may be of benefit to patients at increased risk for cardiotoxicity from HER2-taregeted therapies, particularly those who are treated with an anthracycline-containing regimen.

SUMMARY

Improved risk stratification of patients during HER2-targeted therapy and effective prevention and management strategies for cardiotoxicity are needed to enhance the value of longitudinal cardiac monitoring and increase cardiac safety so that optimal breast cancer treatment can be delivered.

Neratinib: the emergence of a new player in the management of HER2+ breast cancer brain metastasis

HER2-positive (HER2+) breast cancer has become an effectively treatable disease in the era of targeted therapies, and outcomes have improved such that prognosis of this subtype is demonstrated to be superior to HER2-negative disease. Despite these advances, durable responses in HER2+ metastatic disease are challenged by the increased risk for brain metastasis. Neratinib is an irreversible pan-HER kinase inhibitor that has emerged as an effective agent when combined with capecitabine for the management of HER2+ metastatic breast cancer patients with brain metastasis. The randomized, Phase III, NALA trial compares neratinib plus capecitabine to a currently prevailing regimen of lapatinib plus capecitabine and is provided herein. Analysis of NALA portends meaningful changes on the horizon for the management of HER2+ metastatic breast cancer.

Synthesis of 2-arylamino-3-cyanoquinolines via a cascade reaction through a nitrilium intermediate

A new method for the preparation of 2-amino-3-cyanoquinolines from readily available aryldiazonium salts, 2-aminoarylketones, and malononitrile via a cascade reaction is reported. This one-pot approach involves the in situ generation of an N-arylnitrilium intermediate from the direct reaction of aryldiazonium salts and malononitrile, which undergoes intermolecular amination, Knoevenagel condensation, and then aromatization to yield the desired compound in moderate to good yields. This methodology features a quick assembly of C2 and C3 functionalized quinolines.

YES1 activation induces acquired resistance to neratinib in HER2-amplified breast and lung cancers

Molecular‐targeted therapies directed against human epidermal growth factor receptor 2 (HER2) are evolving for various cancers. Neratinib is an irreversible pan‐HER tyrosine kinase inhibitor and has been approved by the FDA as an effective drug for HER2‐positive breast cancer. However, acquired resistance of various cancers to molecular‐targeted drugs is an issue of clinical concern, and emergence of resistance to neratinib is also considered inevitable. In this study, we established various types of neratinib‐resistant cell lines from HER2‐amplified breast and lung cancer cell lines using several drug exposure conditions. We analyzed the mechanisms of emergence of the resistance in these cell lines and explored effective strategies to overcome the resistance. Our results revealed that amplification of YES1, which is a member of the SRC family, was amplified in two neratinib‐resistant breast cancer cell lines and one lung cancer cell line. Knockdown of YES1 by siRNA and pharmacological inhibition of YES1 by dasatinib restored the sensitivity of the YES1‐amplified cell lines to neratinib in vitro. Combined treatment with dasatinib and neratinib inhibited tumor growth in vivo. This combination also induced downregulation of signaling molecules such as HER2, AKT and MAPK. Our current results indicate that YES1 plays an important role in the emergence of resistance to HER2‐targeted drugs, and that dasatinib enables such acquired resistance to neratinib to be overcome.

NSABP FB-7: a phase II randomized neoadjuvant trial with paclitaxel + trastuzumab and/or neratinib followed by chemotherapy and postoperative trastuzumab in HER2+ breast cancer

PURPOSE

The primary aim of NSABP FB-7 was to determine the pathologic complete response (pCR) rate in locally advanced HER2-positive (HER2⁺) breast cancer patients treated with neoadjuvant trastuzumab or neratinib or the combination and weekly paclitaxel followed by standard doxorubicin plus cyclophosphamide. The secondary aims include biomarker analyses.

EXPERIMENTAL DESIGN

pCR was tested for association with treatment, gene expression, and a single nucleotide polymorphism (SNP) in the Fc fragment of the IgG receptor IIIa-158V/F (FCGR3A). Pre-treatment biopsies and residual tumors were also compared to identify molecular changes.

RESULTS

The numerical pCR rate in the trastuzumab plus neratinib arm (50% [95%CI 34-66%]) was greater than that for single-targeted therapies with trastuzumab (38% [95%CI 24-54]) or neratinib (33% [95%CI 20-50]) in the overall cohort but was not statistically significant. Hormone receptor-negative (HR^-) tumors had a higher pCR rate than HR⁺ tumors in all three treatment arms, with the highest pCR rate in the combination arm. Diarrhea was the most frequent adverse event and occurred in virtually all patients who received neratinib-based therapy. Grade 3 diarrhea was reported in 31% of patients; there were no grade 4 events. Our 8-gene signature, previously validated for trastuzumab benefit in two different clinical trials in the adjuvant setting, was correlated with pCR across all arms of NSABP FB-7. Specifically, patients predicted to receive no trastuzumab benefit had a significantly lower pCR rate than did patients predicted to receive the most benefit (P = 0.03). FCGR genotyping showed that patients who were homozygous for the Fc low-binding phenylalanine (F) allele for FCGR3A-158V/F were less likely to achieve pCR.

CONCLUSIONS

Combining trastuzumab plus neratinib with paclitaxel increased the absolute pCR rate in the overall cohort and in HR^- patients. The 8-gene signature, which is validated for predicting trastuzumab benefit in the adjuvant setting, was associated with pCR in the neoadjuvant setting, but remains to be validated as a predictive marker in a larger neoadjuvant clinical trial. HR status, and the FCGR3A-158V/F genotype, also warrant further investigation to identify HER2⁺ patients who may benefit from additional anti-HER2 therapies beyond trastuzumab. All of these markers will require further validation in the neoadjuvant setting.

TRIALS REGISTRATION

ClinicalTrials.gov, NCT01008150. Retrospectively registered on October 5, 2010.

Current Approaches in NSCLC Targeting K-RAS and EGFR

The research and treatment of non-small cell lung cancer (NSCLC) have achieved some important advances in recent years. Nonetheless, the overall survival rates for NSCLC remain low, indicating the importance to effectively develop new therapies and improve current approaches. The understanding of the function of different biomarkers involved in NSCLC progression, survival and response to therapy are important for the development of early detection tools and treatment options. Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (K-RAS) are two of the main significant biomarkers for the management of NSCLC. Mutations in these genes were associated with development and response to therapies. For example, the use of small molecule tyrosine kinase (TK) inhibitors and immunotherapy has led to benefits in some, but not all patients with altered EGFR. In contrast, there is still no effective approved drug to act upon patients harbouring K-RAS mutations. In addition, K-RAS mutations have been associated with lack of activity of TK inhibitors. However, promising approaches aimed to inhibit mutant K-RAS are currently under study. Therefore, this review will discuss these approaches and also EGFR therapies, and hopefully, it will draw attention to the need of continued research in the field in order to improve the outcomes in NSCLC patients.

Nanoformulations of small molecule protein tyrosine kinases inhibitors potentiate targeted cancer therapy

Protein tyrosine kinases (PTKs) are closely related to tumor development and usually participate in apoptosis, DNA repair, and cell proliferation by activating signaling pathways. Therefore, PTKs have become the most promising targets for cancer therapy. In recent years, a large number of studies on the mechanism of tyrosine kinase activation have indicated that tyrosine kinase inhibitors (TKIs) have important clinical significance and application prospects as targeted anticancer drugs because they can effectively block certain cellular signaling pathways, inhibit tumor metastases and reduce tumor proliferation. Although the increasing emergence of anticancer drug resistance limits the clinical application of TKIs, emerging nanotechnology has made it possible to solve this problem. In this work, the state-of-art of small molecule protein tyrosine kinase inhibitors and the applications of drug delivery systems for TKIs are reviewed, and the potentials and challenges for future research of small molecule TKIs are addressed.

Neratinib-based therapy in patients with metastatic HER2-positive breast cancer from Asia

Aim: To evaluate the safety and efficacy of neratinib-based therapy in Asian patients with HER2-positive metastatic breast cancer (MBC). Patients & methods: We performed a pooled analysis of seven early-phase studies of neratinib given either as monotherapy or in combination with chemotherapeutic agents or trastuzumab in patients with advanced solid tumors. Results: A total of 793 patients with HER2-positive MBC were included in the efficacy analysis (Asia: 271 patients; other regions: 522 patients). The overall response rate in patients from Asia was 66.4% (180/271) and the median progression-free survival was 55.6 weeks. The most common adverse event in patients from Asia was diarrhea (all-grade: 96.3%; grade 3: 27.4%). Conclusion: Neratinib-based therapy is safe and effective in patients with HER2-positive MBC from Asia.

Targeted therapeutic options and future perspectives for HER2-positive breast cancer

Over the past 2 decades, there has been an extraordinary progress in the regimens developed for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine (T-DM1) are commonly recommended anti-HER2 target agents by the U.S. Food and Drug Administration. This review summarizes the most significant and updated research on clinical scenarios related to HER2-positive breast cancer management in order to revise the guidelines of everyday clinical practices. In this article, we present the data on anti-HER2 clinical research of neoadjuvant, adjuvant, and metastatic studies from the past 2 decades. We also highlight some of the promising strategies that should be critically considered. Lastly, this review lists some of the ongoing clinical trials, findings of which may soon be available.

Safety and Efficacy of T-DM1 Plus Neratinib in Patients With Metastatic HER2-Positive Breast Cancer: NSABP Foundation Trial FB-10

PURPOSE

Patients with human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer eventually develop resistance to dual-antibody therapy with trastuzumab plus pertuzumab. Mechanisms of resistance have not been well elucidated. We evaluated the safety, tolerability, and efficacy of ado-trastuzumab emtansine (T-DM1) plus neratinib in patients who progressed on trastuzumab plus pertuzumab.

PATIENTS AND METHODS

In this 3 + 3 dose-escalation study, patients with metastatic breast cancer who progressed on trastuzumab, pertuzumab, and a taxane were treated with T-DM1 at 3.6 mg/kg intravenously every 3 weeks and dose-escalating neratinib at 120, 160, 200, or 240 mg/d orally.

RESULTS

Twenty-seven patients were treated across four dose-levels of neratinib. Dose-limiting toxicity in cycle 1 was grade 3 diarrhea in six patients and grade 3 nausea in one; no patient experienced grade 4 diarrhea, and there were no grade 5 toxicities. Other grade 3 to 4 toxicities included nausea (11%), dehydration (11%), electrolyte abnormality (19%), thrombocytopenia (15%), elevated transaminase levels (7%), and fatigue (7%). Twelve (63%) of 19 evaluable patients had an objective response. Responses occurred at all neratinib doses. Plasma cell–free DNA at baseline showed ERBB2 (HER2) amplification in 10 of 27 patients. Deep and more durable responses occurred in patients with cell-free DNA ERBB2 amplification. Two complete responders had high expression of total HER2 and p95HER2 in baseline tissue.

CONCLUSION

We report the recommended phase II dose of T-DM1 3.6 mg/kg and neratinib 160 mg/d for this combination. Possible resistance mechanisms to HER2 antibodies may be loss of the HER2 receptor and high expression of p95HER2. These data provide the basis for an ongoing phase II study to better define the activity of this regimen.

Skin Toxicities with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Cancer Patients: A Meta-Analysis of Randomized Controlled Trials

We fully investigate the skin toxicities of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in cancer patients. The studies about randomized controlled trials in cancer treatment with EGFR-TKIs were retrieved and the systematic evaluation was conducted. The results suggest that EGFR-TKIs significantly increase the risk of skin toxicities including all-grade rash, pruritus, dry skin, and high-grade rash, pruritus. However, the risk of high-grade dry skin did not increase. Rash was the most common toxicity. Physicians should be aware of skin toxicities and should monitor cancer patients when receiving EGFR-TKIs.

Cardiotoxicities of Modern Treatments in Breast Cancer

PURPOSE OF REVIEW

This paper will focus on novel breast cancer therapies used in clinical practice today, as well as review our understanding of standard therapies and their potential impact on cardiovascular health.

RECENT FINDINGS

Established and novel treatments such as anthracyclines, HER2-targeted agents, and immunotherapy have contributed to improvements in breast cancer outcomes; however, these treatments may be associated with an increased risk of cardiovascular injury. The number of available breast cancer treatments continues to expand, as does the need for health care providers to understand the potential impact of these treatments on cardiovascular health. Collaborative approaches in the development of risk stratification, prevention, and surveillance strategies for patients exposed to established and novel breast cancer treatments will facilitate improvements in patient outcomes without compromising their cardiovascular health.

HER2+ breast cancer treatment and cardiotoxicity: monitoring and management

BACKGROUND

Breast cancer is a leading cause of death for women worldwide, with incidence increasing in lower-income countries. For patients with human epidermal growth factor receptor-2-positive (HER2+) breast cancer, widespread availability of several agents targeting the HER2 receptor has resulted in survival gains over the past decades. However, improved survival has resulted in an increased need for management and mitigation of adverse events associated with anticancer therapy. Cardiac adverse events such as decreased ejection fraction and heart failure have been of particular concern in patients with HER2+ breast cancer. Anti-HER2 agents and chemotherapies (specifically anthracyclines, which are frequently used to treat HER2+ disease) have been associated with cardiotoxicity. As increasing numbers of patients are living longer due to more effective therapy, a better understanding of both monitoring and management of cardiotoxicity is urgently needed.

METHODS

A comprehensive review of the literature was conducted via PubMed in January 2018 for phase II and phase III trials of "trastuzumab", "lapatinib", "pertuzumab", "T-DM1", "neratinib", in "breast cancer". Literature was evaluated for content related to cardiac adverse events.

FINDINGS

We describe the incidence of and proposed mechanisms for the cardiotoxicity of available HER2-targeted therapies. We summarize current and emerging practices in the management of cardiotoxicity and provide guidance for routine patient care in real-world practice using illustrative patient scenarios.

CONCLUSIONS

The future of cardiotoxicity management in patients with HER2+ breast cancer is discussed, with a focus on novel techniques to improve cardiac outcomes, including new imaging modalities, biomarkers, interventional therapies, and ongoing trials.