Neoadjuvant-adjuvant pertuzumab in HER2-positive early breast cancer: final analysis of the randomized phase III PEONY trial

Discussion on the mechanism of HER2 resistance in esophagogastric junction and gastric cancer in the era of immunotherapy

Human epidermal growth factor receptor 2 (HER2) is a critical biomarker and therapeutic target in gastric/gastroesophageal junction (G/GEJ) cancers, despite the initial success of HER2-targeted therapies, such as trastuzumab, resistance to these drugs has emerged as a major impediment to effective long-term treatment. This review examines the mechanisms of drug resistance in HER2-positive G/GEJ cancer, the primary mechanisms of resistance explored include alterations in the HER2 receptor itself, such as mutations and changes in expression levels, as well as downstream signaling pathways, and interactions with the tumor microenvironment (TME). Furthermore, the review discusses the Novel therapeutic approaches, including the use of antibody-drug conjugates (ADCs) and combination therapies are assessed for their potential to enhance outcomes. By integrating recent research findings and clinical trials, this review aims to provide oncologists and researchers with insights into developing more effective treatments for patients with drug-resistant HER2-positive G/GEJ cancer.

Efficacy and safety of inetetamab plus pertuzumab and nab-paclitaxel as neoadjuvant therapy for HER2+ breast cancer: A single-arm multicenter phase II clinical trial

The combination of inetetamab and vinorelbine has demonstrated survival benefits with an acceptable toxicity profile in HER2+ metastatic breast cancer (MBC) patients. This multicenter, single-arm, phase II trial further evaluates the efficacy of inetetamab combined with pertuzumab and nab-paclitaxel as neoadjuvant therapy. Treatment-naïve patients with HER2+ early-stage or locally advanced BC received four cycles of intravenous inetetamab (8 mg/kg loading dose, then 6 mg/kg for subsequent doses), intravenous pertuzumab (840 mg loading dose, then 420 mg for subsequent doses), and weekly nab-paclitaxel (125 mg/m2). The primary endpoint was the total pathological complete response (tpCR) rate, defined as ypT0/is and ypN0, assessed by independent central review. From March 2023 to February 2024, 62 patients were enrolled, with the majority (61/62) completing 4 cycles of neoadjuvant therapy. The tpCR rate was 56.5% (95% CI: 43.3%-69.0%). Further analysis showed that patients with estrogen receptor (ER) negative tumors derived greater benefit, with a tpCR rate of 90.9%. The objective response rate was 90.3% (95% CI: 80.1%-96.4%). The most common grade 3 or higher adverse events were neutropenia (32.3%), decreased white blood cell count (19.4%), infectious pneumonia (3.2%), anemia (3.2%), and diarrhea (3.2%). No death occurred during the neoadjuvant treatment. Neoadjuvant treatment with inetetamab, in combination with pertuzumab and nab-paclitaxel, demonstrates good efficacy and tolerability, especially in ER-negative patients.

HER2-Positive Breast Cancer-Current Treatment Management and New Therapeutic Methods for Brain Metastasis

Background: Breast cancer can be classified based on the immunohistochemistry (IHC) phenotypes, defined by the presence or absence of the main IHC markers. IHC phenotyping is important as it determines the prognosis and guides treatment. For example, human epidermal growth factor receptor 2 (HER2) overexpression, which triggers cell growth and division, is observed in HER2-positive breast cancer. Methods: The standard treatment is based on trastuzumab plus pertuzumab in combination with taxane chemotherapy. The possibility of developing metastases depends on those phenotypes. Approximately 25-50% of patients with HER2-positive breast cancer experience brain metastases. This aspect is especially important, as 20% of those patients die as a result. Results: Through the years, many advanced therapies have been introduced to treat brain metastases, including whole brain radiotherapy, stereotactic radiosurgery, and a tyrosine kinase inhibitor (TKI), neratinib. Nonetheless, this still remains a therapeutic challenge. Conclusions: In this review, we focus on the treatment and efficiency of therapies targeting HER2-positive breast cancer, mainly concentrating on the current and newly developed treatment options for brain metastases, such as trastuzumab deruxtecan and tucatinib.

Retrospective Study to Determine Factors Influencing Outcome in Patients With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer Receiving Neoadjuvant Chemotherapy

PURPOSE

There are scant data on patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer treated with neoadjuvant therapy (NAT) in real-world settings with limited access to HER2-targeted therapy.

METHODS

This was a retrospective analysis of patients with nonmetastatic, HER2-positive breast cancer treated with NAT between January 2014 and December 2018 to determine factors affecting pathologic complete response (pCR), event-free survival (EFS), and overall survival (OS).

RESULTS

The cohort comprised 1,004 patients with a median age of 47 years, 533 (53.1%) with clinical T3/T4 tumors, 466 (46.4%) with clinical N2/3 status, and 527 (52.5%) with hormone receptor-positive disease. Trastuzumab was given to 528 (52.6%) patients in the neoadjuvant setting and 711 (70.8%) patients in neoadjuvant and/or postoperative settings. pCR was achieved in 226 (22.5%) patients; the 5-year EFS in the whole cohort, pCR group, and no-pCR group was 63.5% (95% CI, 60.36 to 66.63), 86.1% (95% CI, 81.59 to 90.60), and 57% ([95% CI, 53.47 to 60.52]; P < .001), respectively. In multivariable analysis in the full cohort, smaller tumor size (cT1/T2 v cT3/T4), higher grade (III v II), hormone receptor-negative status, and use of neoadjuvant HER2-targeted therapy were significantly associated with higher pCR, and smaller tumor size (cT1/T2 v cT3/T4), lower node involvement (cN0/N1 v cN2/N3), achievement of pCR, and receiving trastuzumab were significantly associated with higher EFS and OS.

CONCLUSION

In a setting with constrained access to HER2-targeted therapy, lower clinical tumor burden and receiving trastuzumab were significantly associated with increased pCR and survival in patients with HER2-positive breast cancer treated with NAT. Efforts should be made to enhance early diagnosis and access to HER2-targeted therapy worldwide.

De-escalated neoadjuvant weekly nab-paclitaxel with trastuzumab and pertuzumab versus docetaxel, carboplatin, trastuzumab, and pertuzumab in patients with HER2-positive early breast cancer (HELEN-006): a multicentre, randomised, phase 3 trial

BACKGROUND

A previous phase 2 trial showed promising outcomes for patients with HER2-positive early-stage breast cancer using neoadjuvant de-escalation chemotherapy with paclitaxel, trastuzumab, and pertuzumab. We aimed to evaluate the efficacy of weekly nab-paclitaxel compared with the standard regimen of docetaxel plus carboplatin, both with trastuzumab and pertuzumab, as neoadjuvant therapies for patients with HER2-positive breast cancer.

METHODS

HELEN-006 was a multicentre, randomised, phase 3 trial done at six hospitals in China. We enrolled patients aged 18-70 years with untreated, histologically confirmed stage II-III invasive HER2-positive breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. Using an interactive response system, patients were randomly assigned (1:1) under a permuted block randomisation scheme (block size of four), stratified by tumour stage, nodal status, and hormone receptor status. Patients received either intravenous nab-paclitaxel (125 mg/m2 on days 1, 8, and 15) for six 3-week cycles, or intravenous docetaxel (75 mg/m2 on day 1) plus intravenous carboplatin (area under the concentration-time curve 6 mg/mL per min on day 1) for six 3-week cycles. Both groups also received concurrent intravenous trastuzumab, with an initial loading dose of 8 mg/kg and a maintenance dose of 6 mg/kg on day 1, as well as intravenous pertuzumab with a loading dose of 840 mg and a maintenance dose of 420 mg on day 1. This report is the final analysis of the primary endpoint, pathological complete response (ypT0/is ypN0), analysed in all patients who started treatment (modified intention to treat). The trial is registered with ClinicalTrials.gov, NCT04547907, and follow-up of the adjuvant phase is ongoing.

FINDINGS

Between Sept 20, 2020, and March 1, 2023, 789 patients were screened for eligibility, 689 of whom were randomly assigned (343 to the nab-paclitaxel group and 346 to the docetaxel plus carboplatin group). All 689 patients were Asian women. 669 patients received at least one dose of the study treatment and were included in the full analysis set (332 in the nab-paclitaxel group and 337 in the docetaxel plus carboplatin group). Median age of the patients was 50 years (IQR 43-55). Median follow-up time was 26 months (IQR 19-32). 220 (66·3% [95% CI 61·2-71·4]) patients in the nab-paclitaxel group had a pathological complete response, compared with 194 (57·6% [52·3-62·9]) in the docetaxel plus carboplatin group (combined odds ratio 1·54 [95% CI 1·10-2·14]; stratified p=0·011). 100 (30%) patients in the nab-paclitaxel group and 128 (38%) in the docetaxel plus carboplatin group had grade 3-4 adverse events. The most common grade 3-4 adverse events were nausea (22 [7%] in the nab-paclitaxel group vs 76 [23%] in the docetaxel plus carboplatin group), diarrhoea (25 [8%] vs 55 [16%]), and neuropathy (43 [13%] vs eight [2%]). Serious drug-related adverse events were reported in three (1%) patients in the nab-paclitaxel group and five (2%) in the docetaxel plus carboplatin group. No treatment-related deaths were reported in either group.

INTERPRETATION

These findings might suggest a potential advantage of nab-paclitaxel combined with trastuzumab and pertuzumab compared with the standard regimen in neoadjuvant therapy for patients with HER2-positive early breast cancer, suggesting that this new combination might establish a new standard for neoadjuvant treatment in this patient population.

FUNDING

National Natural Science Foundation of China, and Science and Technology Research Projects of Henan Province, China.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Modeling development of breast cancer: from tumor microenvironment to preclinical applications

Breast cancer is a complex disease and its progression is related not only to tumor cells but also to its microenvironment, which can not be sufficiently reflected by the traditional monolayer cell culture manner. The novel human cancer models comprising tumor microenvironment (TME), such as tumor organoids and organs-on-a-chip, has been established in recent years to help elucidate the underlying mechanisms of tumorigenesis and promote the development of cancer therapies. In this review, we first discuss the current state of breast cancer and their treatment strategies, and elucidates the complex properties of TME of breast cancer in vivo. The culture models used in breast cancer research are then summarized with insights into recent development. Finally, we also conclude by discussing the current limitations and future directions of culture models in breast cancer research for providing a preclinical reference for the precise treatment of cancer patients.

Guidance for Canadian Breast Cancer Practice: National Consensus Recommendations for the Systemic Treatment of Patients with HER2+ Breast Cancer in Both the Early and Metastatic Setting

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is an aggressive subtype of breast cancer associated with a poor prognosis when sub-optimally treated. Recent advances include new and effective targeted therapies that have significantly improved outcomes for patients. Despite these advances, there are significant gaps across Canada, underscoring the need for evidence-based consensus guidance to inform treatment decisions. Addressing these gaps is crucial to ensuring that effective therapies are integrated into clinical practice, so as to improve the lives of patients affected by this aggressive form of breast cancer. The Research Excellence, Active Leadership (REAL) Canadian Breast Cancer Alliance is a standing nucleus committee of clinical-academic oncologists across Canada and Breast Cancer Canada, a patient organization. The mandate of this group is to provide evidence-based guidance on best practices in the management of patients with breast cancer. These consensus recommendations were developed using a modified Delphi process with up to three rounds of anonymous voting. Consensus was defined a priori as ≥75% of voters agreeing with the recommendation as written. There are 9 recommendations in the early setting; 7 recommendations in the metastatic setting; and 10 recommendations for patients with brain metastases.

Expression of c-erb-B2 oncoprotein as a neoantigen strategy to repurpose anti-neu antibody therapy in a model of melanoma

In this study, we tested a novel approach of "repurposing" a biomarker typically associated with breast cancer for use in melanoma. HER2/neu is a well characterized biomarker in breast cancer for which effective anti-HER2/neu therapies are readily available. We constructed a lentivirus encoding c-erb-B2, an animal (rat) homolog to HER2/neu. This was used to transfect B16 melanoma in vitro for use in an orthotopic preclinical mouse model, which resulted in expression of rat c-erb-B2 as a neoantigen target for anti-c-erb-B2 monoclonal antibody (7.16.4). The c-erb-B2-expressing melanoma was designated B16/neu. 7.16.4 produced statistically significant in vivo anti-tumor responses against B16/neu. This effect was mediated by NK-cell antibody-dependent cell-mediated cytotoxicity. To further model human melanoma (which expresses < 5% HER2/neu), our c-erb-B2 encoding lentivirus was used to inoculate naïve (wild-type) B16 tumors in vivo, resulting in successful c-erb-B2 expression. When combined with 7.16.4, anti-tumor responses were again demonstrated where approximately 40% of mice treated with c-erb-B2 lentivirus and 7.16.4 achieved complete clinical response and long-term survival. For the first time, we demonstrated a novel strategy to repurpose c-erb-B2 as a neoantigen target for melanoma. Our findings are particularly significant in the contemporary setting where newer anti-HER2/neu antibody-drug therapies have shown increased efficacy.

HER2-targeted therapies for HER2-positive early-stage breast cancer: present and future

Breast cancer (BC) has the second highest incidence among cancers and is the leading cause of death among women worldwide. The human epidermal growth factor receptor 2 (HER2) is overexpressed in approximately 20%-30% of BC patients. The development of HER2-targeted drugs, including monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs) and antibody-drug conjugates (ADCs), has improved the operation rate and pathological remission rate and reduced the risk of postoperative recurrence for HER2-positive early-stage BC (HER2+ EBC) patients. This review systematically summarizes the mechanisms, resistance, therapeutic modalities and safety of HER2-targeted drugs and helps us further understand these drugs and their use in clinical practice for patients with HER2+ EBC.

Mechanisms of acquired resistance to HER2-Positive breast cancer therapies induced by HER3: A comprehensive review

Receptor tyrosine kinases (RTKs) are cell surface receptors with kinase activity that play a crucial role in diverse cellular processes. Among the RTK family members, Human epidermal growth factor receptor 2 (HER2) and HER3 are particularly relevant to breast cancer. The review delves into the complexities of receptor tyrosine kinase interactions, resistance mechanisms, and the potential of anti-HER3 drugs, offering valuable insights into the clinical implications and future directions in this field of study. It assesses the potential of anti-HER3 drugs, such as pertuzumab, in overcoming resistance observed in HER2-positive breast cancer therapies. The review also explores the resistance mechanisms associated with various drugs, including trastuzumab, lapatinib, and PI3K inhibitors, providing insights into the intricate molecular processes underlying resistance development. The review concludes by emphasizing the necessity for further clinical trials to assess the efficacy of HER3 inhibitors and the potential of developing safe and effective anti-HER3 treatments to improve treatment outcomes for patients with HER2-positive breast cancer.

Advancements in Understanding the Hide-and-Seek Strategy of Hibernating Breast Cancer Cells and Their Implications in Oncology from a Broader Perspective: A Comprehensive Overview

Despite recent advancements in technology, breast cancer still poses a significant threat, often resulting in fatal consequences. While early detection and treatments have shown some promise, many breast cancer patients continue to struggle with the persistent fear of the disease returning. This fear is valid, as breast cancer cells can lay dormant for years before remerging, evading traditional treatments like a game of hide and seek. The biology of these dormant breast cancer cells presents a crucial yet poorly understood challenge in clinical settings. In this review, we aim to explore the mysterious world of dormant breast cancer cells and their significant impact on patient outcomes and prognosis. We shed light on the elusive role of the G9a enzyme and many other epigenetic factors in breast cancer recurrence, highlighting its potential as a target for eliminating dormant cancer cells and preventing disease relapse. Through this comprehensive review, we not only emphasise the urgency of unravelling the dynamics of dormant breast cancer cells to improve patient outcomes and advance personalised oncology but also provide a guide for fellow researchers. By clearly outlining the clinical and research gaps surrounding dormant breast cancer cells from a molecular perspective, we aim to inspire further exploration of this critical area, ultimately leading to improved patient care and treatment strategies.

Chinese Society of Clinical Oncology (CSCO) Breast Cancer guidelines 2024

Background

Developing guidelines for the diagnosis and treatment of common cancers in China based on the evidence-based practice, the availability of diagnosis and treatment products, and the up-to-date advances in precision medicine is one of the basic tasks of the Chinese Society of Clinical Oncology Breast Cancer (CSCO BC) Committee.

Methods

Protocols with high evidence level and good availability are used as the Level I recommendations; protocols with relatively high evidence level but slightly lower expert consensus or with poor availability are used as the Level II recommendations; and protocols that are clinically applicable but with low evidence level are regarded as the Level III recommendations. Based on the findings of clinical research at home and abroad and the opinions of CSCO BC experts, the CSCO BC guidelines determine the levels of recommendations for clinical application.

Results

For human epidermal growth factor receptor 2 (HER2)-positive breast cancer, a combination of trastuzumab and pertuzumab regimen were recommended as Level I recommendation for neoadjuvant and first line metastatic breast cancer. Pyrotinib is also recommended as Level I recommendation in first line and second line therapy according to the latest studies conducted in China. Antibody drug conjugates was also recommended for patients with trastuzumab progression. For triple negative breast cancer, immunotherapy in early and metastatic breast cancer was highlighted and listed as new chapters in this version of guideline. For hormone receptor (HR)-positive breast cancer, cyclin dependent kinase 4/6 (CDK4/6) was recommended in different stages, especially in adjuvant therapy. There was also a new chapter for HER2-low breast cancer stratified by HR status.

Conclusions

We firmly believe that evidence-based, availability-concerned, and consensus-based guidelines will be more feasible for clinical practice in China and in other countries with similar situations.

Implementation of antibody-drug conjugates in HER2-positive solid cancers: Recent advances and future directions

In recent decades, there has been a surge in the approval of monoclonal antibodies for treating a wide range of hematological and solid malignancies. These antibodies exhibit exceptional precision in targeting the surface antigens of tumors, heralding a groundbreaking approach to cancer therapy. Nevertheless, monoclonal antibodies alone do not show sufficient lethality against cancerous cells compared to chemotherapy. Consequently, a new class of anti-tumor medications, known as antibody-drug conjugates (ADCs), has been developed to bridge the divide between monoclonal antibodies and cytotoxic drugs, enhancing their therapeutic potential. ADCs are chemically synthesized by binding tumor-targeting monoclonal antibodies with cytotoxic payloads through linkers that are susceptible to cleavage by intracellular proteases. They combined the accurate targeting of monoclonal antibodies with the potent efficacy of cytotoxic chemotherapy drugs while circumventing systemic toxicity and boasting superior lethality over standalone targeted drugs. The human epidermal growth factor receptor (HER) family, which encompasses HER1 (also known as EGFR), HER2, HER3, and HER4, plays a key role in regulating cellular proliferation, survival, differentiation, and migration. HER2 overexpression in various tumors is one of the most frequently targeted antigens for ADC therapy in HER2-positive cancers. HER2-directed ADCs have emerged as highly promising treatment modalities for patients with HER2-positive cancers. This review focuses on three approved anti-HER2 ADCs (T-DM1, DS-8201a, and RC48) and reviews ongoing clinical trials and failed trials based on anti-HER2 ADCs. Finally, we address the notable challenges linked to ADC development and underscore potential future avenues for tackling these hurdles.