Neratinib after trastuzumab-based adjuvant therapy in HER2-positive breast cancer (ExteNET): 5-year analysis of a randomised, double-blind, placebo-controlled, phase 3 trial

Human Epidermal Growth Factor Receptor 2-Positive (HER2+) Early Breast Cancer Treatment and Outcomes by Risk of Recurrence: A Retrospective US Electronic Health Records Study

Background/Objectives: This study analyzed real-world data to assess patient characteristics, treatment patterns, and clinical outcomes in patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (eBC), as data for this patient group are limited. Methods: This was a retrospective observational cohort study of patients in a US electronic health record-derived deidentified database. Patient characteristics, treatment patterns, and clinical outcomes were analyzed overall and by risk of recurrence (high-risk versus non-high-risk). Results: Of 1290 patients, 366 (28.4%) were classified as high-risk and 924 (71.6%) as non-high-risk. At 5 years, high-risk versus non-high-risk eBC had a lower probability of invasive disease-free survival (72.3% [95% CI: 66.8-77.1%] vs. 80.7% [95% CI: 77.6-83.5%]), distant recurrence-free survival (78.7% [95% CI: 74.1-83.6%] vs. 89.3% [95% CI: 86.9-91.7%]), and overall survival (86.9% [95% CI: 82.3-90.4%] vs. 91.8% [95% CI: 89.4-93.7%]), and a shorter time to mBC diagnosis (22.6 vs. 34.1 months, respectively). Neoadjuvant therapy use increased from 18.2% in 2011-2013 to 67.3% in 2018-2021 in high-risk eBC and from 4.1% to 34.4% in non-high-risk eBC. However, 32.7% of eligible patients with high-risk eBC did not receive neoadjuvant therapy in 2018-2021. Use of post-neoadjuvant and adjuvant therapy increased in high-risk (but not non-high-risk) eBC from 81.8% in 2011-2013 to 91.8% in 2018-2021. Conclusions: High-risk HER2+ eBC manifested more aggressively than non-high-risk eBC. Utilization of neoadjuvant and (post-neo)adjuvant therapy increased over time. However, despite guideline recommendations, uptake of neoadjuvant therapy remains suboptimal.

ESMO-Magnitude of Clinical Benefit Scale version 2.0 (ESMO-MCBS v2.0)

BACKGROUND

The ESMO-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated tool to assess the magnitude of clinical benefit from new cancer therapies, with planned updates based upon recognition of new needs and shortcomings. This paper describes the development of ESMO-MCBS v2.0.

METHODOLOGY

The revision process incorporates nine steps: (i) review of critiques and suggestions and identification of problems in the application of ESMO-MCBS v1.1; (ii) identification of shortcomings for revision in the upcoming version; (iii) drafting solutions addressing identified shortcomings; (iv) field-testing of solutions; (v) preparation of a near-final revised version for peer review for reasonableness by members of the ESMO Faculty and ESMO Guidelines Committee; (vi) amendments based on peer review for reasonableness; (vii) near-final review by members of the ESMO-MCBS Working Group; (viii) final amendments; (ix) final review and approval by members of the ESMO-MCBS Working Group and the ESMO Executive Board.

RESULTS

Seventeen issues for revision or amendment were considered, and 13 amendments were formulated to address identified shortcomings. In the curative setting, studies evaluated based on disease-free survival now credit improved time without treatment or disease even when overall survival is not significantly improved, and studies with small absolute gain in disease-free survival are credited more conservatively. Additionally, acute and persistent toxicity annotations are added. In the non-curative setting, the approach to crediting a difference in the tail of overall survival and progression-free survival curves is more statistically valid, and the toxicity evaluation has been revised. In peer review all amendments were found to be either reasonable or mostly reasonable. The amendments changed the scoring of 85/353 of evaluated studies.

CONCLUSIONS

The amendments incorporated into ESMO-MCBS v2.0 change the scores of 13.6% of evaluated studies (10.5% downgraded, 3.1% upgraded) and add toxicity annotations to 45.5% of the studies in the curative setting, and improve its discriminatory capacity and utility.

Potential prognostic value of HER2/CEP17 FISH ratio in HER2-positive non-metastatic breast cancer: a real-world study

BACKGROUND

HER2-positive breast cancer (BC) requires anti-HER2 therapy. We aimed to determine whether the expression of the HER2/centromeric probe for chromosome 17 (CEP17) ratio was associated with prognosis in patients with HER2-positive non-metastatic BC.

METHODS

267 HER2-positive BC were enrolled between January 2010 and December 2011. Stabilized inverse probability treatment weighting (sIPTW) was used to balance baseline characteristics. Real-world disease-free survival (DFS) and overall survival (OS) was analyzed.

RESULTS

The median follow-up time was 10.3 years (interquartile range: 9.4-10.8 years). HER2/CEP17 ratio of > 7.0 was defined as the HER2 ultra-positive group; a HER2/CEP17 ratio of ≤ 7.0 was defined as the HER2 normal-positive group. After sIPTW adjustment, no differences were observed in DFS and OS when anti-HER2 therapy was unknown, and similarly in the patients who were recorded as not receive trastuzumab (all p > 0.05). Interestingly, HER2 ultra-positive group had a worse DFS than the normal-positive group (hazard ratio [HR] = 2.72, p = 0.02), but there was no difference in OS (p = 0.30) in patients did receive trastuzumab. The multivariate Cox models also showed that the HER2 ultra-positive had worse DFS than HER2 normal-positive patients (HR = 3.71; p < 0.01).

CONCLUSION

For non-metastatic HER2-positive BC with or without trastuzumab treatment, the HER2/CEP17 ratio did not predict DFS and OS. However, our study supported that HER2 ultra-positive group had a worse DFS than the normal-positive group among non-metastatic HER2-positive BC patients receiving trastuzumab; therefore, this could be a potential predictor of DFS in these 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.

Cardiovascular adverse events associated with EGFR and HER2 dual TKIs: a pharmacovigilance study based on the FAERS database

BACKGROUND

EGFR and HER2 dual TKIs have been approved for the treatment of advanced breast cancer in patients who are HER2-positive for second and/or third-line treatment. However, there is a lack of attention to the cardiovascular adverse events (AEs) caused by EGFR and HER2 dual TKIs.

RESEARCH DESIGN AND METHODS

We analyzed data spanning between March 2007 and June 2024 using the FAERS database and the reporting odds ratio, proportional reporting ratio, and Bayesian confidence propagation neural network to perform disproportionality analysis.

RESULTS

Compared with non-cardiovascular AEs, cardiovascular AEs were associated with more severe clinical outcomes, such as higher rates of hospitalization, life-threatening events, disability, and death. Our analysis revealed that lapatinib had a higher-than-expected reporting rate for three SMQs, including cardiac failure, embolic and thrombotic events, and cardiomyopathy. No significant cardiovascular signals were observed for neratinib.

CONCLUSION

Disproportionality analysis results revealed a positive signal for cardiac failure, embolic and thrombotic events, and cardiomyopathy of lapatinib, and no positive signal for neratinib. We should pay attention to high-risk signals in clinical practice and monitor them appropriately.

Signaling pathway dysregulation in breast cancer

This article provides a comprehensive analysis of the signaling pathways implicated in breast cancer (BC), the most prevalent malignancy among women and a leading cause of cancer-related mortality globally. Special emphasis is placed on the structural dynamics of protein complexes that are integral to the regulation of these signaling cascades. Dysregulation of cellular signaling is a fundamental aspect of BC pathophysiology, with both upstream and downstream signaling cascade activation contributing to cellular process aberrations that not only drive tumor growth, but also contribute to resistance against current treatments. The review explores alterations within these pathways across different BC subtypes and highlights potential therapeutic strategies targeting these pathways. Additionally, the influence of specific mutations on therapeutic decision-making is examined, underscoring their relevance to particular BC subtypes. The article also discusses both approved therapeutic modalities and ongoing clinical trials targeting disrupted signaling pathways. However, further investigation is necessary to fully elucidate the underlying mechanisms and optimize personalized treatment approaches.

Triple-positive breast cancer: navigating heterogeneity and advancing multimodal therapies for improving patient outcomes

Triple-positive breast cancer (TPBC), a unique subtype of luminal breast cancer, is characterized by concurrent positivity for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Owing to the crosstalk between the ER and HER2 signaling pathways, the standard of care and drug resistance of this particular subtype are difficult challenges. Recent research and clinical trials have indicated a shift in the treatment paradigm for TPBC from single-target therapies to multi-pathway, multitarget strategies aiming to comprehensively modulate intricate signaling networks, thereby overcoming resistance and enhancing therapeutic outcomes. Among multiple strategies, triple-drug therapy has emerged as a promising treatment modality, demonstrating potential efficacy in patients with TPBC. Moving forward, there is a critical need to perform in-depth analyses of specific mechanisms of cancer pathogenesis and metastasis, decipher the complex interactions between different genes or proteins, and identify concrete molecular targets, thus paving the way for the development of tailored therapeutic strategies to combat TPBC effectively.

Challenges and prospects in HER2-positive breast cancer-targeted therapy

Breast cancer remains the most prevalent malignancy among women globally and ranks as the leading cause of cancer-related mortality in this demographic. Approximately 13 %-15 % of all breast cancer cases are classified as HER2-positive, a subtype associated with a particularly unfavorable prognosis. A large number of patients with HER2-positive breast cancer continue to face disease progression after receiving standardized treatment. Given these challenges, a thorough exploration into the mechanisms underlying drug resistance in HER2-targeted therapy is imperative. This review focuses on the factors related to drug resistance in HER2-targeted therapy, including tumor heterogeneity, antibody-binding efficacy, variations in the tumor microenvironment, and abnormalities in signal activation and transmission. Additionally, corresponding strategies to counteract these resistance mechanisms are discussed, to advance therapeutic efficacy and clinical benefits in the management of HER2-positive breast cancer.

Pre-Clinical Rationale for Amcenestrant Combinations in HER2+/ER+ Breast Cancer

HER2-positive/oestrogen receptor-positive (HER2+/ER+) represents a unique breast cancer subtype. The use of individual HER2- or ER-targeting agents can lead to the acquisition of therapeutic resistance due to compensatory receptor crosstalk. New drug combinations targeting HER2 and ER could improve outcomes for patients with HER2+/ER+ breast cancer. In this study, the pre-clinical rationale is explored for combining amcenestrant (Amc), a selective oestrogen receptor degrader (SERD), with HER2-targeted therapies including trastuzumab, trastuzumab-emtansine (T-DM1) and tyrosine kinase inhibitors (TKIs). The combination of Amc and anti-HER2 therapies was investigated in a panel of four HER2+/ER+ cell lines: BT-474, MDA-MB-361, EFM-192a and a trastuzumab-resistant variant BT-474-T. Proliferation (IC50 and matrix combination assays) was determined using acid phosphatase assays. HER2/ER and intracellular signalling pathway protein levels/activity were investigated by western blot. Apoptosis was assessed using caspase 3/7 assays. Additivity and synergy were observed between Amc and the TKIs neratinib, lapatinib and tucatinib in all cell lines. Amc increased the anti-proliferative effect of trastuzumab in MDA-MB-361 and BT-474-T. Addition of Amc also increased anti-proliferative efficacy of T-DM1 in BT-474-T. TKI/Amc combinations reduced p-HER2 and ER levels and resulted in increased apoptosis. Higher ER expression in MDA-MB-361 and BT-474-T was associated with greater potential for synergy. In conclusion, the combination of Amc- and HER2-targeted treatments has potential as a therapeutic strategy for the treatment of HER2+/ER+ breast cancer and warrants further clinical investigation to validate safety and efficacy in patients.

Cardiovascular Health Considerations for Primary Care Physicians Treating Breast Cancer Survivors

Breast cancer (BC) survivors are at increased risk for cardiovascular disease (CVD) and require their primary care physicians to manage their long-term general medical care, including cardiovascular (CV) health. Yet, evidence exists that some primary care physicians possess insufficient knowledge about survivorship care. With the goal of bridging these knowledge gaps, a PubMed review was conducted from July 7, 2020, through October 2, 2020, with an updated PubMed review from January 3, 2024, through April 28, 2024, focusing on CV health considerations in the primary care of BC survivors. Search terms included variations of "breast cancer survivors" and "cardiovascular." In total, 152 publications were included. Breasts cancer survivors may have increased CVD risk because some anticancer therapies are cardiotoxic and risk factors for BC often also increase the risk for CVD. Multiple risk factors overlap for BC and CVD such as older age, Western diet, early menarche, physical inactivity, high body mass index, and smoking. In this review, results are summarized from studies that report the presence of CV risk factors and CVD in BC survivors. Also described are the CV effects of BC therapies (chemotherapy, hormonal agents, targeted therapies, and radiotherapy) and the type of CV evaluation (cardiac imaging and measurement of biomarkers) that these patients may need. Primary care physicians have an important role in managing the CV health of BC survivors from preventing, assessing, and managing CV risk factors to referring patients to appropriate specialists when needed.

HER2-Positive Breast Cancer Treatment and Resistance

HER2-positive (+) breast cancer is an aggressive disease with poor prognosis, a narrative that changed drastically with the advent and approval of trastuzumab, the first humanized monoclonal antibody targeting HER2. In addition to another monoclonal antibody, more classes of HER2-targeted agents, including tyrosine kinase inhibitors, and antibody-drug conjugates were developed in the years that followed. While these potent therapies have substantially improved the outcome of patients with HER2+ breast cancer, resistance has prevailed as a clinical challenge ever since the arrival of targeted agents. Efforts to develop new treatment regimens to treat/overcome resistance is futile without a primary understanding of the mechanistic underpinnings of resistance. Resistance could be attributed to mechanisms that are either specific to the tumor epithelial cells or those that emerge through changes in the tumor microenvironment. Reactivation of the HER receptor layer due to incomplete blockade of the HER receptor layer or due to alterations in the HER receptors is one of the major mechanisms. In other instances, resistance may occur due to deregulations in key downstream signaling such as the PI3K/AKT or RAS/MEK/ERK pathways or due to the emergence of compensatory pathways such as ER, other RTKs, or metabolic pathways. Potent new targeted agents and approaches to target key actionable drivers of resistance have already been identified, many of which are in early clinical development or under preclinical evaluation. Ongoing and future translational research will continue to uncover additional therapeutic vulnerabilities, as well as new targeted agents and approaches to treat and/or overcome anti-HER2 treatment resistance.

Clinical Impact of Somatic Genomic Testing on Breast Cancer Care

Developments in our understanding of the molecular biology of breast cancer have had a direct impact on the investigations needed to provide optimal breast cancer care. Somatic genomic tests are now used routinely to inform decisions regarding adjuvant chemotherapy use in selected early breast cancer patients, and to identify patients with advanced disease who can potentially benefit from novel targeted agents. In this overview, we describe the somatic genomic tests currently available within the National Health Service (NHS) for early and advanced breast cancer patients. We review the underlying biology and the evidence base for clinical utility of these tests in routine clinical practice. In addition, we identify the somatic genomic biomarkers currently in use in breast cancer clinical trials that are most likely to influence future breast cancer management. We also consider the challenges associated with tissue-based genomic testing in advanced breast cancer and the role of circulating tumour deoxyribonucleic acid (ctDNA) testing.

Current status of precision oncology in adult glioblastoma

The concept of precision oncology, the application of targeted drugs based on comprehensive molecular profiling, has revolutionized treatment strategies in oncology. This review summarizes the current status of precision oncology in glioblastoma (GBM), the most common and aggressive primary brain tumor in adults with a median survival below 2 years. Targeted treatments without prior target verification have consistently failed. Patients with BRAF V600E-mutated GBM benefit from BRAF/MEK-inhibition, whereas targeting EGFR alterations was unsuccessful due to poor tumor penetration, tumor cell heterogeneity, and pathway redundancies. Systematic screening for actionable molecular alterations resulted in low rates (< 10%) of targeted treatments. Efficacy was observed in one-third and currently appears to be limited to BRAF-, VEGFR-, and mTOR-directed treatments. Advancing precision oncology for GBM requires consideration of pathways instead of single alterations, new trial concepts enabling rapid and adaptive drug evaluation, a focus on drugs with sufficient bioavailability in the CNS, and the extension of target discovery and validation to the tumor microenvironment, tumor cell networks, and their interaction with immune cells and neurons.

Risk of locoregional recurrence after breast cancer surgery by molecular subtype-a systematic review and network meta-analysis

BACKGROUND

The prevention of locoregional recurrence (LRR) is crucial in breast cancer, as it translates directly into reduced breast cancer-related death. Breast cancer is subclassified into distinct intrinsic biological subtypes with varying clinical outcomes.

AIMS

To perform a systematic review and network meta-analysis (NMA) to determine the rate of LRR by breast cancer molecular subtype.

METHODS

A NMA was performed as per PRISMA-NMA guidelines. Molecular subtypes were classified by St Gallen expert consensus statement (2013). Analysis was performed using R and Shiny.

RESULTS

Five studies were included including 6731 patients whose molecular subtypes were available. Overall, 47.3% (3182/6731) were Luminal A (LABC: estrogen receptor (ER) + /human epidermal growth factor receptor-2 (HER2) - /progesterone receptor (PR) + or Ki-67 < 20%), 25.5% (1719/6731) were Luminal B (LBBC: ER + /HER2 - /PR - or Ki-67 ≥ 20%), 11.2% (753/6731) were Luminal B-HER2 + (LBBC-HER2: ER + /HER2 +), 6.9% (466/6731) were HER2 + (HER2 ER - /HER2 +), and finally 9.1% (611/6731) were triple-negative breast cancer (TNBC: ER - /HER2 -). The median follow-up was 74.0 months and the overall LRR rate was 4.0% (271/6731). The LRR was 1.7% for LABC (55/3182), 5.1% for LBBC (88/1719), 6.0% for LBBC-HER2 (45/753), 6.0% for HER2 (28/466), and 7.9% for TNBC (48/611). At NMA, patients with TNBC (odds ratio (OR) 3.73, 95% confidence interval (CI) 1.80-7.74), HER2 (OR 3.24, 95% CI 1.50-6.99), LBBC-HER2 (OR 2.38, 95% CI 1.09-5.20), and LBBC (OR 2.20, 95% CI 1.07-4.50) were significantly more likely to develop LRR compared to LABC.

CONCLUSION

TNBC and HER2 subtypes are associated with the highest risk of LRR. Multidisciplinary team discussions should consider these findings to optimize locoregional control following breast cancer surgery.

Identification of HER2-positive breast cancer molecular subtypes with potential clinical implications in the ALTTO clinical trial

In HER2-positive breast cancer, clinical outcome and sensitivity to HER2-targeted therapies are influenced by both tumor and microenvironment features. However, we are currently unable to depict the molecular heterogeneity of this disease with sufficient granularity. Here, by performing gene expression profiling in HER2-positive breast cancers from patients receiving adjuvant trastuzumab in the ALTTO clinical trial (NCT00490139), we identify and characterize five molecular subtypes associated with the risk of distant recurrence: immune-enriched, proliferative/metabolic-enriched, mesenchymal/stroma-enriched, luminal, and ERBB2-dependent. Additionally, we validate the biological profiles of the subtypes and explore their prognostic/predictive value in external cohorts, namely the NeoALTTO trial (NCT00553358), SCAN-B (NCT02306096), I-SPY2 (NCT01042379), METABRIC and TCGA. Immune-enriched tumors present better survival outcomes, in contrast to mesenchymal/stroma-enriched and proliferative/metabolic-enriched tumors, while luminal and ERBB2-dependent tumors are characterized by low and high rates of pathological complete response, respectively. Of note, these molecular subtypes provide the rationale for treatment approaches leveraging the heterogeneous biology of HER2-positive breast cancer.

Molecular Characterization and Classification of HER2-Positive Breast Cancer Inform Tailored Therapeutic Strategies

HER2-positive breast cancer is an aggressive subtype that accounts for 15% to 20% of all breast cancers. Recent studies have suggested that HER2-positive breast cancer is a group of heterogeneous diseases with different sensitivities to standard treatment regimens. Revealing the molecular heterogeneity of HER2-positive breast cancer could potentially enable more precise treatment strategies. In this study, we performed multiomics profiling on a HER2-positive breast cancer cohort and identified four transcriptome-based subtypes. The classical HER2 (HER2-CLA) subtype comprised 28.3% of the samples and displayed high ERBB2 activation and significant benefit from anti-HER2 therapy. The immunomodulatory (HER2-IM) subtype (20%) featured an immune-activated microenvironment, potentially suitable for de-escalated treatment and immunotherapy. The luminal-like (HER2-LUM) subtype (30.6%) possessed similar molecular features of hormone receptor-positive HER2-negative breast cancer, suggesting endocrine therapy and CDK4/6 inhibitors as a potential therapeutic strategy. Lastly, the basal/mesenchymal-like (HER2-BM) subtype (21.1%) had a poor response to current dual HER2-targeted therapy and could potentially benefit from tyrosine kinase inhibitors. The molecular characteristics and clinical features of the subtypes were further explored across multiple cohorts, and the feasibility of the proposed treatment strategies was validated in patient-derived organoid and patient-derived tumor fragment models. This study elucidates the molecular heterogeneity of HER2-positive breast cancer and paves the way for a more tailored treatment. Significance: Illumination of the inherent heterogeneity within HER2-positive breast cancers through the delineation of distinct molecular subtypes lays the groundwork for developing more personalized treatment strategies based on specific patient characteristics.

Neratinib plus dasatinib is highly synergistic in HER2-positive breast cancer in vitro and in vivo

BACKGROUND

HER2-targeted therapies have revolutionised the treatment of HER2-positive breast cancer. However, de novo resistance or the emergence of acquired resistance is a persistent clinical problem. Here we report that neratinib, an irreversible pan-HER inhibitor, in combination with the multi-kinase inhibitor dasatinib, currently used to treat certain leukemias, has strong anti-proliferative effects against models of HER2-positive breast cancer that are innately resistant to trastuzumab or have acquired resistance to neratinib.

METHODS

Neratinib plus dasatinib was examined in a panel of 20 breast cancer cell lines, including HER2-positive, estrogen-receptor-positive, triple negative, and acquired HER2-targeted therapy resistant models. Drug effects on migration and apoptosis induction was evaluated and signaling alterations were determined by reverse phase protein array (RPPA). In vivo efficacy was examined using orthotopically-implanted HCC1954 cells.

RESULTS

Synergy was observed in cell lines innately resistant to trastuzumab, models with acquired resistance to neratinib, and in triple negative breast cancer cell lines. Further investigation showed that neratinib plus dasatinib induced apoptosis and inhibited cell migration to a greater degree than either drug alone. RPPA revealed that the combination caused suppression of key survival signaling through EGFR, Akt, and MAPK inhibition. In vivo, neratinib plus dasatinib was well tolerated and had a prolonged anti-tumor effect against HCC1954 xenografts.

CONCLUSIONS

This study provides a strong pre-clinical rationale for the clinical investigation neratinib and dasatinib in HER2+ breast cancer.

Oral solid dosage form using alternate crystalline neratinib maleate anhydrous form: Pharmaceutical, bioequivalent, and clinical perspectives

Neratinib (an active pharmaceutical ingredient [API]) is an irreversible pan-human epidermal growth factor receptor (HER) inhibitor used to treat HER2-positive breast cancer. The dosage form (marketed in the United States, China, Europe, and other regions) is a tablet for oral administration, and the brand product (NERLYNX) has patent protection for the crystalline neratinib maleate monohydrate form. This paper describes the product development using stable crystalline neratinib maleate anhydrous form, stability study, bioequivalence (BE) study of the products, and discussion of the adverse effects observed in the clinical study.

Final analysis of the ALTTO trial: adjuvant trastuzumab in sequence or in combination with lapatinib in patients with HER2-positive early breast cancer [BIG 2-06/NCCTG N063D (Alliance)]

BACKGROUND

Dual anti-human epidermal growth factor receptor 2 (HER2) blockade has improved the outcomes of patients with early and metastatic HER2-positive breast cancer. Here we present the final 10-year analysis of the ALTTO trial.

PATIENTS AND METHODS

The ALTTO trial (NCT00490139) is a prospective randomized, phase III, open-label, multicenter study that investigated the role of adjuvant chemotherapy and trastuzumab alone, in combination or sequentially with lapatinib. The primary endpoint was disease-free survival (DFS) and secondary endpoints included overall survival (OS), time to distant recurrence and safety.

RESULTS

Overall, 6281 patients with HER2-positive early breast cancer were included in the final efficacy analysis in three treatment groups: trastuzumab (T), lapatinib + trastuzumab (L + T) and trastuzumab followed by lapatinib (T→L). Baseline characteristics were well balanced between groups. At a median follow-up of 9.8 years, the addition of lapatinib to trastuzumab and chemotherapy did not significantly improve DFS nor OS. The 10-year DFS was 77% in T, 79% in L + T and 79% in T→L, and the 10-year OS was 87%, 89% and 89%, respectively. The incidence of any cardiac event was low and similar in the three treatment groups.

CONCLUSIONS

With a longer follow-up, no significant improvement was observed in DFS in patients treated with dual anti-HER2 blockade with lapatinib + trastuzumab compared to trastuzumab alone. The 10-year survival rates for the combination group are consistent with other studies that have explored dual anti-HER2 therapy.

Patterns in use and tolerance of adjuvant neratinib in patients with hormone receptor (HR)-positive, HER2-positive early-stage breast cancer

PURPOSE

One year of neratinib therapy is known to derive a significant invasive disease-free survival (iDFS) benefit in early-stage, hormone receptor-positive (HR +), HER2 + , node-positive breast cancer after trastuzumab-based adjuvant therapy. Limitations to neratinib use include significant gastrointestinal side effects, which often result in treatment discontinuation. In this study, we aimed to identify clinicopathologic features associated with adjuvant neratinib use and factors impacting treatment completion.

METHODS

We performed a retrospective review of patients with early-stage HR + HER2 + breast cancer who were prescribed neratinib from 2017 to 2023 at our institution. We used the electronic medical record to extract information on patient characteristics, clinical features, and treatment information. Patients were identified as high risk based on definitions adapted from the standard high-risk definition in HR + HER2- breast cancer combined with studies correlating high Ki67 or high tumor grade with lower recurrence-free survival. Statistical analysis was performed using two-sided T-tests and chi-square tests.

RESULTS

We identified 62 eligible patients of whom 55% completed 1 year of neratinib and 45% did not. Sixty percent (N = 37) of patients offered neratinib were considered high risk at diagnosis. The most common reason for neratinib discontinuation was inability to tolerate side effects (54%) followed by pill burden (18%). The most common side effect experienced by patients was diarrhea despite anti-diarrheal prophylaxis (56%), followed by rash (8%). Patients who received an up-titration of neratinib were more likely to complete the full course of neratinib when compared to those who did not (76% vs. 40.5% p = 0.013). The median starting dose of those who completed neratinib treatment was 140 vs. 240 mg in those who did not (p = 0.016). Neither group experienced a statistically significant greater likelihood of treatment holds or dose reductions. In terms of outcomes, 10 patients had progression of disease of whom 7 did not complete neratinib treatment (p = 0.169). Interestingly, those 7 patients developed metastatic disease and 57% (N = 4) had central nervous system metastases.

CONCLUSION

Patients are more likely to complete 1 year of adjuvant neratinib with dose up-titration. Dose reductions and interruptions did not affect neratinib adherence in our patient population. Seven patients (11%) in our study developed metastatic disease, all of whom did not complete adjuvant neratinib treatment.

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.

PI3K Mutation Profiles on Exons 9 (E545K and E542K) and 20 (H1047R) in Mexican Patients With HER-2 Overexpressed Breast Cancer and Its Relevance on Clinical-Pathological and Survival Biological Effects

Background: Trastuzumab resistance is associated with overexpressing the human epidermal growth factor receptor 2 (HER-2), which results from the altered phosphoinositide 3-kinase (PI3K) pathway in breast cancer patients. Objective: We quantified the frequency of PI3K enzyme single and double-point mutations in Mexican patients with HER-2 overexpressing breast cancer and its association with clinical-pathological variables. Methods: We embedded HER-2 breast samples in paraffin from 60 patients, extracted their DNA, and evaluated PI3K mutations in 49 HER-2-positive breast tumors. We focused on mutations for one exon 20 (H1047R) and two exon 9 PI3K (E545K, E542K) hotspots and characterized them as single and double-point mutations. The mean patient follow-up was 86 months. Results: Of 49 patients who tested positive for HER-2 breast cancer, 14.28% showed mutations in PI3K, 71.42% single-point, and 28.56% double-point mutations. We found single-point mutations in H1047R (42.85%) and E545K (28.57%). Only two patients exhibited double-point mutations: one in E542K/E545K and another in H1047R/E545K (14.28% each). Although we observed lower survival in patients with mutations in PI3K, we did not find a significant association between these factors (p = 0.191). However, single and double-point mutations in PI3K were significantly associated with the clinical stages of diagnosis and tumor size (p = 0.027 and p = 0.04, respectively). Conclusion: Single and double-point mutations in PI3K are related to tumor size and advanced clinical-pathological traits in Mexican patients with HER-2 overexpression, and future molecular studies are necessary to understand these findings.

Bedside implications of the use of surrogate endpoints in solid and haematological cancers: implications for our reliance on PFS, DFS, ORR, MRD and more

Clinical endpoints, such as overall survival, directly measure relevant outcomes. Surrogate endpoints, in contrast, are intermediate, stand-in measures of various tumour-related metrics and include tumour growth, tumour shrinkage, blood results, etc. Surrogates may be a time point measurement, that is, tumour shrinkage at some point (eg, response rate) or biomarker-assessed disease status, measured at given time points (eg, circulating tumour DNA, ctDNA). They can also be measured over time, as with progression-free survival, which is the time until a patient presents with either disease progression or death. Surrogates are increasingly used in trials supporting the marketing authorisation of novel oncology drugs. Yet, the trial-level correlation between surrogates and clinical endpoints-meaning to which extent an improvement in the surrogate predicts an improvement in the direct endpoint-is often moderate to low. Here, we provide a comprehensive classification of surrogate endpoints: time point measurements and time-to-event endpoints in solid and haematological malignancies. Also, we discuss an overlooked aspect of the use of surrogates: the limitations of surrogates outside trial settings, at the bedside. Surrogates can result in the inappropriate stopping or switching of therapy. Surrogates can be used to usher in new strategies (eg, ctDNA in adjuvant treatment of colon cancer), which may erode patient outcomes. In liquid malignancies, surrogates can mislead us to use novel drugs and replace proven standards of care with costly medications. Surrogates can lead one to intensify treatment without clear improvement and possibly worsening quality of life. Clinicians should be aware of the role of surrogates in the development and regulation of drugs and how their use can carry real-world, bedside implications.

Ferroptosis - a potential feature underlying neratinib-induced colonic epithelial injury

PURPOSE

Neratinib, a small-molecule tyrosine kinase inhibitor (TKI) that irreversibly binds to human epidermal growth factor receptors 1, 2 and 4 (HER1/2/4), is an approved extended adjuvant therapy for patients with HER2-amplified or -overexpressed (HER2-positive) breast cancers. Patients receiving neratinib may experience mild-to-severe symptoms of gut toxicity including abdominal pain and diarrhoea. Despite being a highly prevalent complication in gut health, the biological processes underlying neratinib-induced gut injury, especially in the colon, remains unclear.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) and histology were integrated to study the effect of, and type of cell death induced by neratinib on colonic tissues collected from female Albino Wistar rats dosed with neratinib (50 mg/kg) daily for 28 days. Additionally, previously published bulk RNA-sequencing and CRISPR-screening datasets on human glioblastoma SF268 cell line and glioblastoma T895 xenograft, and mouse TBCP1 breast cancer cell line were leveraged to elucidate potential mechanisms of neratinib-induced cell death.

RESULTS

The severity of colonic epithelial injury, especially degeneration of surface lining colonocytes and infiltration of immune cells, was more pronounced in the distal colon than the proximal colon. Sequencing showed that apoptotic gene signature was enriched in neratinib-treated SF268 cells while ferroptotic gene signature was enriched in neratinib-treated TBCP1 cells and T895 xenograft. However, we found that ferroptosis, but less likely apoptosis, was a potential histopathological feature underlying colonic injury in rats treated with neratinib.

CONCLUSION

Ferroptosis is a potential feature of neratinib-induced colonic injury and that targeting molecular machinery governing neratinib-induced ferroptosis may represent an attractive therapeutic approach to ameliorate symptoms of gut toxicity.

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.

Clinicopathological Factors Predicting Pathological Complete Response to Neoadjuvant Anti-HER2 Therapy in HER2-Positive Breast Cancer

INTRODUCTION

Human epidermal growth factor receptor 2 (HER2)-targeted therapies have shown effectiveness against HER2-positive breast cancer. This makes neoadjuvant chemotherapy (NAC) a valuable option for treating both early and advanced stages of the disease. The tumor's response to HER2-targeted NAC provides crucial prognostic information. Additionally, it allows for tailoring adjuvant treatment strategies for HER2+ breast cancer based on pathological responses. This study aimed to investigate the clinicopathological factors that influence tumor response.

METHODS

We retrospectively analyzed 122 patients diagnosed with HER2+ breast cancer. These patients received NAC and HER2-directed therapy between January 2018 and December 2022 at the Pusan National University Yangsan Hospital. Following surgery, tumor response was evaluated, categorizing patients into two groups: pathological complete response (pCR) and non-pCR groups. We analyzed data on various factors, including age, NAC regimen, type of breast and axillary surgery, clinical stage (cTNM), historical grade, and preoperative levels of carcinoembryonic antigen, cancer antigen 15-3 (CA 15-3), estrogen receptor (ER), progesterone receptor (PR), HER2, p53, and KI-67.

RESULTS

Out of the 122 patients, 75 achieved pCR, while 47 did not. Most clinicopathological factors showed no significant difference between the pCR and non-pCR groups. However, several factors were associated with a higher pCR rate: normal preoperative CA 15-3 levels (odds ratio [OR]: 3.74, confidence interval [CI]: 1.19-11.72, p = 0.02), preoperative ER positivity (OR: 2.65, CI: 1.25-5.59, p = 0.01), PR negativity (OR: 3.92, CI: 1.82-8.45, p < 0.05), and strong preoperative HER2 immunohistochemistry (IHC) 3+ staining. Multivariate analysis confirmed that PR negativity (OR: 2.8, CI: 1.23-6.42, p = 0.01) and strong preoperative HER2 IHC 3+ staining (OR: 0.18, CI: 0.03-0.84, p = 0.04) were independent predictors of a higher pCR rate.

CONCLUSIONS

A pCR after NAC impacts patient prognosis and influences the choice of adjuvant treatment for HER2+ breast cancer. Clinicopathological factors can help predict responses to HER2-targeted NAC. In our study, pre-ER/PR negativity, high pre-HER2 levels, and normal CA 15-3 levels were found to be potential predictors of pCR. These findings may contribute to developing more effective treatment strategies for HER2+ breast cancer.

Advances from targeted therapy for non-metastatic HER2-positive inflammatory breast cancer

Among inflammatory breast cancer (IBC) patients, over one-third have HER2-overexpressing (HER2+) tumors. Pathologic complete response (pCR) rates to neoadjuvant targeted and chemotherapy for patients with HER2+ non-metastatic IBC now apporach 60% and favorable long-term survival rates are being reported for those with a pCR. Immune mechanisms contributing to this phenomenon include antibody-mediated immune activation and induction of memory T-cell reponses which may explain the sustained antitumor response seen after discontinuation of targeted therapies.

Trastuzumab-Induced Cardiotoxicity: When and How Much Should We Worry?

This review critically analyzes the incidence of trastuzumab-induced left ventricular systolic dysfunction and congestive heart failure (CHF), distinguishing between cases with and without prior anthracycline exposure. It highlights the fact that the elevated risk of trastuzumab-induced cardiotoxicity is closely associated with prior anthracycline exposure. In the absence of prior anthracycline exposure, the incidence rates of trastuzumab-induced cardiotoxicity, particularly CHF (ranging from 0% to 0.5%), are largely comparable with those reported in the general population, especially when reversibility is taken into account. Current cardiac surveillance recommendations during trastuzumab treatment have not yet adapted to the increasing adoption of nonanthracycline treatment strategies and the associated low risk of cardiotoxicity. We propose a refined monitoring protocol to reduce the frequency of cardiac evaluations for low-risk to moderate-risk patients, especially those receiving nonanthracycline treatments. By focusing on patients at high risk or those with prior anthracycline exposure, this strategy seeks to optimize the cost-effectiveness of cardiac care in oncology.

Pharmacotherapy for cervical cancer: current standard of care and new perspectives

INTRODUCTION

Cervical cancer, while highly preventable, remains an international public health challenge especially in under resourced regions. Although early-stage cervix confined cancers are often amenable to surgical resection, larger tumors deemed locally advanced cervical cancer (LACC) necessitate systemic therapy as part of chemoradiation therapy. Moreover, systemic therapy is the standard therapeutic approach for those presenting with primary metastasis or recurrence.

AREAS COVERED

While several agents have been approved to treat recurrent cervical cancer including checkpoint inhibitors as well as both biomarker agnostic and specific antibody drug conjugates, the development of agents added to chemoradiation has been less fruitful. Until recently, the addition of novel therapies to chemoradiation has been negative in terms of improving outcomes; however, results of a recent Phase III clinical trial (NCT04221945) in LACC demonstrated that the addition of pembrolizumab to standard of care chemoradiation was associated with an improvement in progression-free survival and resulted in an FDA approval for this therapy. This observation led to the first change in treating LACC since the early 2000s.

EXPERT OPINION

Improvements in systemic therapy both alone and in combination with chemoradiation for cervical cancer have been realized. Ongoing research is needed for therapeutic options following immunotherapy.

Preclinical and clinical evaluation through serial colonoscopic evaluation of neratinib-induced diarrhea in HER2-positive breast cancer-A pilot study

The irreversible pan-HER tyrosine kinase inhibitor neratinib is approved for patients with HER2-positive, early-stage and metastatic breast cancer (BC). Neratinib-associated diarrhea is the most common reason for early discontinuation. Preclinical studies identified mechanisms of neratinib-induced diarrhea and rationale for prophylactic and preventive measures. We studied effects of neratinib on rat intestines and conducted a phase 2 study of colon pathogenesis in patients with HER2-positive BC treated with neratinib (NCT04366713). Colon samples from female albino Wistar rats receiving neratinib or vehicle were examined for histopathological changes. Patients with HER2-positive BC received neratinib 240 mg once daily for up to 1 year. Colonoscopy biopsies were collected at baseline and at Day 28 to identify changes consistent with rat pathologies. Rat colons were markedly altered in appearance, with similar short circuit currents (Isc) and responses to carbachol and forskolin. Mucosal barrier loss and/or significant increase in secretory propensity in neratinib- versus control-treated animals were not seen. Two of four endpoint-evaluable patients presented with mild pathological changes, largely comparable with the rat model. Preclinical evidence supports an inflammatory component of neratinib-induced diarrhea without mucosal barrier function loss. Colonoscopy findings in patients with BC indicate mild or no pathological changes in the colon due to neratinib treatment.

Frequency of Deleterious Germline Variants in HER2-Low Breast Cancer Patients Using a Hereditary Multipanel Gene Testing

HER2-Low is defined as low levels of HER2 expression, based on a score of 1+ on immunohistochemical (IHC) assay or as an IHC score of 2+ and negative results on in situ hybridization (ISH or FISH). They are a heterogeneous population of breast cancers that vary in prognosis and sensitivity to systemic treatments. The frequency and clinical characteristics of pathogenic germline variants (PGVs) in HER2-Low breast cancer (BC) patients is not defined. We analyzed results from patients with BC who underwent multi-gene panel testing (MGPT) (maximum 145 genes) between 2018-2019. We reclassified HER-2 status accordingly. Relationships between the variables of interest were assessed by adopting the proportional regression Cox models. Of a total of 167 BC patients who underwent MGPT, half were hormone-receptor-positive. The median age was 45 years. About two thirds of the patients were in the earlier stage of BC. A total of 57% of the cases were reclassified as HER-2-negative or -Low. PGVs were found in 19% of the patients overall, as follows: seven BRCA1, four BRCA2, two ATM, one ATR, two CFTR, three CHEK2, one FANCA, one MERTK, one MLH1, three MUTYH, one RAD50, three RAD51C, one RECQL4, and two TP53 mutations. In HER2-Low, 26.5% of the patients had PGVs, and in the overall cohort, this was 19.8%. In conclusion, differences in the prevalence of deleterious germline mutations in HER2-Low BC patients compared to non-HER2-Low BC patients were identified. Similar alterations in BRCA were observed in this group of patients compared to the overall cohort. Germline genetic tests should be evaluated in larger cohorts of patients with HER2-Low status to better address the findings.

Neoadjuvant inetetamab and pertuzumab with taxanes and carboplatin (TCbIP) In locally advanced HER2-positive breast cancer: a prospective cohort study with propensity-matched analysis

BACKGROUND

Inetetamab is the first domestically developed innovative anti-HER2 monoclonal antibody in China, proven effective and safe in HER2-positive advanced breast cancer. However, its efficacy and safety in neoadjuvant treatment of HER2-positive locally advanced breast cancer (LABC) remain to be validated.

METHODS

This prospective cohort study aimed to evaluate the efficacy and safety of inetetamab combined with pertuzumab, taxanes, and carboplatin (TCbIP) in neoadjuvant therapy for HER2-positive LABC, comparing it to data from patients treated with the TCbHP regimen (trastuzumab combined with pertuzumab, taxanes, and carboplatin) using propensity score matching (PSM). The primary endpoint was total pathological complete response (tpCR). Adverse events (AEs), objective response rate (ORR), and near-pCR were key secondary endpoints.

RESULTS

Forty-four patients with clinical stage IIA-IIIC HER2-positive LABC were prospectively enrolled and treated with the TCbIP regimen. The tpCR rate among 28 patients who completed surgery was 60.7%, comparable to and slightly higher than the TCbHP group in PSM (60.7% vs. 53.6%, P = 0.510). The ORR was 96.4%, and the DCR reached 100.0%. The most common ≥ grade 3 AE was neutropenia (21.4% vs. 11.9%, P = 0.350). No significant reduction in left ventricular ejection fraction was observed, and no patient withdrew from treatment due to AEs.

CONCLUSION

Neoadjuvant therapy with TCbIP showed good efficacy and safety in patients with HER2-positive LABC and might be another promising option for neoadjuvant treatment.

TRIAL REGISTRATION

NCT05749016 (registration date: Nov 01, 2021).

Health-related quality of life outcomes reporting associated with FDA approvals in haematology and oncology

Objective

Health-related quality of life (HRQoL) outcomes are important in making clinical and policy decisions. This study aimed to examine the HRQoL reporting in cancer drug trials leading to Food and Drug Administration (FDA) approvals.

Methods and analysis

This retrospective cohort study analysed HRQoL data for trials leading to FDA approvals between July 2015 and May 2020. Proportion of included trials that reported HRQoL, latency between FDA approval and first report of HRQoL data, HRQoL outcomes, and their correlation with OS (overall survival) and PFS (progression-free survival) were analysed.

Results

Of the 233 trials associated with 207 FDA approvals, HRQoL was reported in 50% of trials, of which only 42% had the data reported by the time of FDA approval. There were no changes in frequency of HRQoL reporting between 2015 and 2020. HRQoL data were first reported in the primary publication in only 30% trials. Of the 115 trials with HRQoL data available, HRQoL improved in 43%, remained stable in 53% and worsened in 4% of trials. Among the trials that led to FDA approvals based on surrogate endpoints (79%), HRQoL was reported in 45% and improved only in 18% trials. There was no association between OS and PFS benefit and HRQoL outcomes.

Conclusion

Rates of HRQoL reporting were suboptimal in trials that led to FDA approvals with no improvements seen between 2015 and 2020. HRQoL reporting was often delayed and not presented in the primary publication. HRQoL reporting was further sparse in trials with approvals based on surrogate endpoints and HRQoL improved in only a minority of them.

Incorporation of immunotherapies and nanomedicine to better normalize angiogenesis-based cancer treatment

Neoadjuvant targeting of tumor angiogenesis has been developed and approved for the treatment of malignant tumors. However, vascular disruption leads to tumor hypoxia, which exacerbates the treatment process and causes drug resistance. In addition, successful delivery of therapeutic agents and efficacy of radiotherapy require normal vascular networks and sufficient oxygen, which complete tumor vasculopathy hinders their efficacy. In view of this controversy, an optimal dose of FDA-approved anti-angiogenic agents and combination with other therapies, such as immunotherapy and the use of nanocarrier-mediated targeted therapy, could improve therapeutic regimens, reduce the need for administration of high doses of chemotherapeutic agents and subsequently reduce side effects. Here, we review the mechanism of anti-angiogenic agents, highlight the challenges of existing therapies, and present how the combination of immunotherapies and nanomedicine could improve angiogenesis-based tumor treatment.

Systemic oncological therapy in breast cancer patients on dialysis

The advancement of renal replacement therapy has significantly enhanced the survival rates of patients with end-stage renal disease (ESRD) over time. However, this prolonged survival has also been associated with a higher likelihood of cancer diagnoses among these patients including breast cancer. Breast cancer treatment typically involves surgery, radiation, and systemic therapies, with approaches tailored to cancer type, stage, and patient preferences. However, renal replacement therapy complicates systemic therapy due to altered drug clearance and the necessity for dialysis sessions. This review emphasizes the need for optimized dosing and administration strategies for systemic breast cancer treatments in dialysis patients, aiming to ensure both efficacy and safety. Additionally, challenges in breast cancer screening and diagnosis in this population, including soft-tissue calcifications, are highlighted.

IRX4204 Induces Senescence and Cell Death in HER2-positive Breast Cancer and Synergizes with Anti-HER2 Therapy

PURPOSE

Rexinoids, agonists of nuclear retinoid X receptor (RXR), have been used for the treatment of cancers and are well tolerated in both animals and humans. However, the usefulness of rexinoids in treatment of breast cancer remains unknown. This study examines the efficacy of IRX4204, a highly specific rexinoid, in breast cancer cell lines and preclinical models to identify a biomarker for response and potential mechanism of action.

EXPERIMENTAL DESIGN

IRX4204 effects on breast cancer cell growth and viability were determined using cell lines, syngeneic mouse models, and primary patient-derived xenograft (PDX) tumors. In vitro assays of cell cycle, apoptosis, senescence, and lipid metabolism were used to uncover a potential mechanism of action. Standard anti-HER2 therapies were screened in combination with IRX4204 on a panel of breast cancer cell lines to determine drug synergy.

RESULTS

IRX4204 significantly inhibits the growth of HER2-positive breast cancer cell lines, including trastuzumab and lapatinib-resistant JIMT-1 and HCC1954. Treatment with IRX4204 reduced tumor growth rate in the MMTV-ErbB2 mouse and HER2-positive PDX model by 49% and 44%, respectively. Mechanistic studies revealed IRX4204 modulates lipid metabolism and induces senescence of HER2-positive cells. In addition, IRX4204 demonstrates additivity and synergy with HER2-targeted mAbs, tyrosine kinase inhibitors, and antibody-drug conjugates.

CONCLUSIONS

These findings identify HER2 as a biomarker for IRX4204 treatment response and demonstrate a novel use of RXR agonists to synergize with current anti-HER2 therapies. Furthermore, our results suggest that RXR agonists can be useful for the treatment of anti-HER2 resistant and metastatic HER2-positive breast cancer.

Neratinib could be effective as monotherapy or in combination with trastuzumab in HER2-low breast cancer cells and organoid models

BACKGROUND

Previous studies have suggested that patients with HER2-low breast cancers do not benefit from trastuzumab treatment although the reasons remain unclear.

METHODS

We investigated the effect of trastuzumab monotherapy and its combination with different HER2 targeting treatments in a panel of breast cancer cell lines and patient-derived organoids (PDOs) using biochemical methods and cell viability assays.

RESULTS

Compared to sensitive HER2 over-expressing (IHC3 + ) breast cancer cells, increasing doses of trastuzumab could not achieve IC50 in MDA-MB-361 (IHC 2 + FISH + ) and MDA-MB-453 (IHC 2 + FISH-) cells which showed an intermediate response to trastuzumab. Trastuzumab treatment induced upregulation of HER ligand release, resulting in the activation of HER receptors in these cells, which could account for their trastuzumab insensitivity. Adding a dual ADAM10/17 inhibitor to inhibit the shedding of HER ligands in combination with trastuzumab only showed a modest decrease in the cell viability of HER2-low breast cancer cells and PDOs. However, the panHER inhibitor neratinib was an effective monotherapy in HER2-low breast cancer cells and PDOs, and showed additive effects when combined with trastuzumab.

CONCLUSION

This study demonstrates that neratinib in combination with trastuzumab may be effective in a subset of HER2-low breast cancers although further validation is required in a larger panel of PDOs and in future clinical studies.

Updated Austrian treatment algorithm for metastatic triple-negative breast cancer

Approximately 15% of newly diagnosed breast cancer patients have neither hormone receptors expression nor HER2 overexpression and/or HER2/neu gene amplification. This subtype of breast cancer is known as Triple Negative Breast Cancer (TNBC), and carries a significantly elevated risk of local and distant recurrence. In comparison with other breast cancer subtypes, there is a higher rate of visceral and brain metastases. The majority of metastases of TNBC are diagnosed within three years after initial breast cancer diagnosis. While there have been major advances in hormone-receptor- positive and in human epidermal growth factor receptor 2 (HER2)-positive disease over the past two decades, only limited improvements in outcomes for patients with triple negative breast cancer (TNBC) have been observed. A group of Austrian breast cancer specialists therefore convened an expert meeting to establish a comprehensive clinical risk-benefit profile of available mTNBC therapies and discuss the role sacituzumab govitecan may play in the treatment algorithm of the triple-negative breast cancer patients.

Seeing the Trees From the Forest: Challenges in Subgroup Analysis-Based Guidelines in Oncology

As clinical trials in oncology require substantial efforts, maximizing the insights gained from them by conducting subgroup analyses is often attempted. The goal of these analyses is to identify subgroups of patients who are likely to benefit, as well as the subgroups of patients who are unlikely to benefit from the studied intervention. International guidelines occasionally include or exclude novel medications and technologies for specific subpopulations based on such analyses of pivotal trials without requiring confirmatory trials. This Perspective discusses the importance of providing a complete dataset of clinical information when reporting subgroup analyses and explains why such transparency is key for better clinical interpretation of the results and the appropriate application to clinical care, by providing examples of transparent reporting of clinical studies and examples of incomplete reporting of clinical studies.

Efficacy and safety of Trastuzumab Emtansine in treating human epidermal growth factor receptor 2-positive metastatic breast cancer in Chinese population: a real-world multicenter study

Background

Trastuzumab emtansine (T-DM1) has been approved worldwide for treating metastatic breast cancer (mBC) in patients who have received first-line therapy, shown disease progression, and are human epidermal growth factor receptor 2 (HER2)-positive. T-DM1 received approval in China to treat early-stage breast cancer (BC) in 2020 and for mBC in 2021. In March 2023, T-DM1 was included in medical insurance coverage, significantly expanding the eligible population.

Materials and methods

This post-marketing observational study aimed to assess the safety and effectiveness of T-DM1 in real-world clinical practice in China. This study enrolled 31 individuals with HER2-positive early-stage BC and 70 individuals with HER2-positive advanced BC from 8 study centers in Shandong Province, China. The T-DM1 dosage was 3.6 mg/kg injected intravenously every 3 weeks until the disease advanced or the drug toxicity became uncontrollable, whichever occurred earlier. Additionally, efficacy and safety information on T-DM1 were collected.

Results

During the 7-month follow-up period, no recurrence or metastases were observed in patients who had early-stage BC. The disease control rate was 31.43% (22/70) in patients with advanced BC. The most common adverse effect of T-DM1 was thrombocytopenia, with an incidence of 69.31% (70/101), and the probability of Grade ≥ 3 thrombocytopenia was 11.88% (12/101).

Conclusion

This real-world study demonstrated that T-DM1 had good efficacy and was well tolerated by both HER2-positive early-stage BC and mBC patients.

Progression from ductal carcinoma in situ to invasive breast cancer: molecular features and clinical significance

Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25-60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

Hormone Receptor-Positive/HER2-Positive Breast Cancer: Hormone Therapy and Anti-HER2 Treatment: An Update on Treatment Strategies

Hormone receptor (HR)-positive/HER2-positive breast cancer represents a distinct subtype expressing estrogen and progesterone receptors with an overexpression of HER2. Approximately 14% of female breast cancer cases are HER2-positive, with the majority being HR-positive. These tumors show a cross-talk between the hormonal and HER2 pathways; the interaction has implications for the treatment options for the disease. In this review, we analyze the biology of HR-positive/HER2-positive breast cancer and summarize the evidence concerning the standard of care options both in neoadjuvant/adjuvant settings and in advanced disease. Additionally, we focus on new trials and drugs for HR-positive/HER2-positive breast cancer and the new entity: HER2-low breast cancer.

Catalysts of Healing: A Symphony of Synthesis and Clinical Artistry in Small-Molecule Agents for Breast Cancer Alleviation

Breast cancer, characterized by its molecular intricacy, has witnessed a surge in targeted therapeutics owing to the rise of small-molecule drugs. These entities, derived from cutting-edge synthetic routes, often encompassing multistage reactions and chiral synthesis, target a spectrum of oncogenic pathways. Their mechanisms of action range from modulating hormone receptor signaling and inhibiting kinase activity, to impeding DNA damage repair mechanisms. Clinical applications of these drugs have resulted in enhanced patient survival rates, reduction in disease recurrence, and improved overall therapeutic indices. Notably, certain molecules have showcased efficacy in drug-resistant breast cancer phenotypes, highlighting their potential in addressing treatment challenges. The evolution and approval of small-molecule drugs have ushered in a new era for breast cancer therapeutics. Their tailored synthetic pathways and defined mechanisms of action have augmented the precision and efficacy of treatment regimens, paving the way for improved patient outcomes in the face of this pervasive malignancy. The present review embarks on a detailed exploration of small-molecule drugs that have secured regulatory approval for breast cancer treatment, emphasizing their clinical applications, synthetic pathways, and distinct mechanisms of action.

Effects of orally administered crofelemer on the incidence and severity of neratinib-induced diarrhea in female dogs

Targeted therapies have increased cancer therapy-related diarrhea (CTD) burden, with high incidence and/or severity of diarrhea for some agents that inhibit epidermal growth factor receptor and receptor tyrosine kinases. Neratinib is a pan-HER tyrosine kinase inhibitor approved for breast cancer treatment and causes severe diarrhea in >95% of patients. Crofelemer, a novel intestinal chloride ion channel modulator, is an approved antidiarrheal drug for symptomatic relief of noninfectious diarrhea in patients with HIV/AIDS receiving antiretroviral therapy. The objective of this study was to evaluate the effectiveness of crofelemer prophylaxis in reducing the incidence /severity of neratinib-induced diarrhea without concomitant administration of loperamide in female beagle dogs. A pilot study using 3 dogs determined a maximum daily tolerated dose of neratinib was between 40 and 80 mg; this dose would induce a consistent incidence/severity of diarrhea without risking severe dehydration. In the definitive study, 24 female beagle dogs (8/group) received neratinib once daily and placebo capsules (CTR) four times/day, or neratinib once daily and crofelemer 125 mg delayed-release tablets given two times (BID), or neratinib once daily and crofelemer 125 mg delayed-release tablets given four times per day (QID). Fecal scores were collected twice daily using an established canine stool scoring scale called the Purina Fecal Scoring (PFS) System. After 28 days, using analysis of covariance (ANCOVA), dogs in the CTR group had a significantly higher average number of weekly loose/watery stools (PFS of 6 or 7) when compared to either crofelemer BID (8.71±2.2 vs. 5.96±2.2, p = 0.028) or crofelemer QID (8.70±2.2 vs. 5.74±2.2, p = 0.022) treatment groups. The average number of weekly loose/watery stools were not different between the crofelemer BID and QID treatment groups (p = 0.84). This study showed that crofelemer prophylaxis reduced the incidence/severity of neratinib-associated diarrhea in female beagle dogs without the need for any loperamide administration.

Molecular Targeting of the Human Epidermal Growth Factor Receptor-2 (HER2) Genes across Various Cancers

Human epidermal growth factor receptor 2 (HER2) belongs to the ErbB family, a group of four transmembrane glycoproteins with tyrosine kinase activity, all structurally related to epidermal growth factor receptor (EGFR). These tyrosine kinases are involved in the transmission of cellular signals controlling normal cell growth and differentiation. If this transmission goes awry, it can lead to dysregulated growth of the cell. HER2 specifically can be implicated in the pathogenesis of at least eight malignancies. HER2 positivity quickly became a well-characterized indicator of aggressiveness and poor prognosis, with high rates of disease progression and mortality. After realizing the implication of HER2, it first became investigated as a target for treatment in breast cancer, and later expanded to areas of research in other cancer types. To this day, the most therapeutic advancements of anti-HER2 therapy have been in breast cancer; however, there have been strong advancements made in the incorporation of anti-HER2 therapy in other cancer types as well. This comprehensive review dissects HER2 to its core, incorporating the most up to date information. The topics touched upon are discussed in detail and up to 200 published sources from the most highly recognized journals have been integrated. The importance of knowing about HER2 is exemplified by the groundbreaking advancements that have been made, and the change in treatment plans it has brought to the oncological world in the last twenty years. Since its groundbreaking discovery there have been significant breakthroughs in knowledge regarding the actual receptor, the receptors biology, its mechanism of action, and advancements in tests to detect HER2 and significant strides on how to best incorporate targeted treatment. Due to the success of this field thus far, the review concludes by discussing the future of novel anti-HER2 therapy currently in development that everyone should be aware of.

An Open-Label Study of Subcutaneous CpG Oligodeoxynucleotide (PF03512676) in Combination with Trastuzumab in Patients with Metastatic HER2+ Breast Cancer

OBJECTIVES

CpG ODN is a Toll-like receptor 9 agonist with immunotherapeutic potential for many cancer types, including aggressive breast cancers. There is strong interest in utilizing CpG ODN as an adjuvant to improve clinical efficacy of current treatments and immunogenicity of breast cancers not traditionally responsive to active immunotherapy, such as those that are human epidermal growth factor receptor 2 (HER2)-positive. This study aimed to study the efficacy and safety of combination CpG ODN plus anti-HER2 antibody trastuzumab treatment in patients with advanced/metastatic breast cancer.

METHODS

This single-arm, open-label phase II clinical trial treated patients (n = 6) with advanced/metastatic HER2-positive breast cancer with weekly subcutaneous CpG ODN and trastuzumab. Patients may have received any number of prior therapies to be enrolled (most enrolled at median 1 prior line of chemotherapy). Peripheral blood was collected at baseline and weeks 2, 6, 12, and 18 for immune analyses. Six patients were enrolled and 50% achieved stable disease (SD) response.

RESULTS

Median PFS was 8.3 months. Three of the six patients enrolled opted to stop treatment due to tolerability issues. Multiplex assay for cytokine measurements revealed significantly higher VEGF-D levels at week 2 compared to baseline. Peripheral blood mononuclear cells analyzed by flow cytometry showed a significant increase in monocytic MDSC between weeks 6 and 12. Patients with progressive disease tended to have higher levels of week 6 monocytic MDSC and PD-1+ T cells than patients with SD. NK cell populations did not significantly change throughout treatment.

CONCLUSIONS

CpG ODN and trastuzumab treatment of metastatic HER2 + breast cancer was safe but was not tolerable for all patients. This combination did induce potentially predictive immune profile changes in treated patients with metastatic HER2 + breast cancer, the significance of which needs to be further explored.

Targeting the EGFR/RAS/RAF signaling pathway in anticancer research: a recent update on inhibitor design and clinical trials (2020-2023)

INTRODUCTION

Recent years have seen significant strides in drug developmenttargeting the EGFR/RAS/RAF signaling pathway which is critical forcell growth and proliferation. Protein-protein interaction networksamong EGFR, RAS, and RAF proteins offer insights for drug discovery. This review discusses the drug design and development efforts ofinhibitors targeting these proteins over the past 3 years, detailingtheir structures, selectivity, efficacy, and combination therapy.Strategies to combat drug resistance and minimize toxicities areexplored, along with future research directions.

AREA COVERED

This review encompasses clinical trials and patents on EGFR, KRAS,and BRAF inhibitors from 2020 to 2023, including advancements indesign and synthesis of proteolysis targeting chimeras (PROTACs) forprotein degradation.

EXPERT OPINION

To tackle drug resistance, designing allosteric fourth-generationEGFR inhibitors is vital. Covalent, allosteric, or combinationaltherapies, along with PROTAC degraders, are key methods to addressresistance and toxicity in KRAS and BRAF inhibitors.

Treatment of residual disease following neoadjuvant therapy in breast cancer

Substantial advances have been made in the systemic treatment of breast cancer with residual disease following neoadjuvant therapy. We reviewed recent and ongoing studies informing the standard clinical management of residual disease by subtype: HER2+, TNBC, and HR+/HER2-, as well as strategies for BRCA+ disease. We conclude with a discussion of ongoing clinical trials and current controversies regarding the treatment of residual disease in breast cancer.

Novel HER-2 Targeted Therapies in Breast Cancer

Human epidermal growth factor 2 (HER-2)-positive breast cancer represents 15-20% of all breast cancer subtypes and has an aggressive biological behavior with worse prognosis. The development of HER-2-targeted therapies has changed the disease's course, having a direct impact on survival rates and quality of life. Drug development of HER-2-targeting therapies is a prolific field, with numerous new therapeutic strategies showing survival benefits and gaining regulatory approval in recent years. Furthermore, the acknowledgement of the survival impact of HER-2-directed therapies on HER-2-low breast cancer has contributed even more to advances in the field. The present review aims to summarize the newly approved therapeutic strategies for HER-2-positive breast cancer and review the new and exploratory HER-2-targeted therapies currently under development.