Cardiac Safety of Reduced Cardiotoxicity Surveillance During HER2-Targeted Therapy.

Background: Echocardiograms are recommended every 3 months to monitor for cancer therapy-related cardiac dysfunction (CTRCD) among patients treated with HER2-targeted therapy, despite increasing use of safer regimens associated with low CTRCD risk.

Objectives: This study evaluated the cardiac safety of reduced CTRCD surveillance performed every 6 months during non-anthracycline HER2-targeted treatment.

Methods: This non-randomized clinical trial enrolled 190 patients with HER2-positive breast cancer treated with non-anthracycline HER2-targeted therapy.

Antibody drug conjugates in metastatic brain tumors: current landscape, therapeutic potential and challenges.

The management of brain metastases (BrM) remains a major clinical challenge due to limited drug delivery across the blood-brain barrier (BBB) and the need for simultaneous CNS and systemic disease management, often with competing therapeutic strategies. Antibody-drug conjugates (ADCs) are a promising class of drugs that offers precision therapy by combining the specificity of monoclonal antibodies with potent chemotherapeutics for targeted tumor delivery. This review explores the current landscape of ADCs in BrMs, challenges in BBB penetration, and CNS-specific toxicities, including interactions with radiotherapy and the risk of radiation necrosis.

Sequential Antibody-Drug Conjugate Therapy in Patients With Metastatic Breast Cancer Treated With Sacituzumab Govitecan and Trastuzumab Deruxtecan.

Purpose: Sacituzumab govitecan (SG) and trastuzumab deruxtecan (T-DXd) are antibody-drug conjugates (ADCs) approved for the treatment of human epidermal growth factor receptor 2 (HER2)-low metastatic breast cancer (MBC). Both carry topoisomerase-1-inhibiting payloads, and it is unknown whether these drugs retain activity when used sequentially.

Methods: Patients who received both T-DXd and SG for treatment of MBC were eligible.

Patient-reported outcomes from DESTINY-Breast04: trastuzumab deruxtecan versus physician's choice of chemotherapy in patients with HER2-low mBC.

Background: The phase 3 DESTINY-Breast04 trial demonstrated superior efficacy and acceptable safety with trastuzumab deruxtecan (T-DXd) vs physician's choice of chemotherapy in previously treated patients with human epidermal growth factor receptor 2 (HER2)-low metastatic breast cancer (mBC). We report the patient-reported outcomes (PROs), focusing on the hormone receptor-positive cohort.

Patients And Methods: Patients were randomized 2:1 to T-DXd (5.

Treatment patterns and outcomes in HER2-low metastatic breast cancer patients previously treated with chemotherapy: a US real-world cohort study.

Purpose: Real-world outcomes are poorly understood for patients with human epidermal growth factor receptor 2 (HER2)-low (immunohistochemistry 1+ or 2+ with negative in situ hybridization) metastatic breast cancer (mBC).

Methods: Using for the first time a nationwide electronic health record-derived de-identified database, we assessed demographics, treatment patterns, and outcomes of patients with HER2-low mBC who previously received one line of chemotherapy in the metastatic setting. The post-chemotherapy line was termed the index line of therapy (LOT).

Local Therapy for Isolated Central Nervous System Progression Among Patients Receiving Antibody-Drug Conjugate Therapy.

Purpose: Antibody drug conjugates (ADCs) are an increasingly important class of therapeutics among patients with breast, lung, urothelial, and other malignancies. Guidelines recommend local therapy and continuation of current systemic therapy among patients with isolated brain relapse. We describe the clinical outcomes of this approach among patients receiving ADCs.

Predictors of response to CDK4/6i retrial after prior CDK4/6i failure in ER+ metastatic breast cancer.

After disease progression on endocrine therapy (ET) plus a CDK4/6 inhibitor, there is no standardized sequence for subsequent treatment lines for estrogen receptor positive (ER+) metastatic breast cancer (MBC). CDK4/6i retrial as a treatment strategy is commonplace in modern clinical practice; however, the available prospective data investigating this strategy have had inconclusive results. To frame this data in a real-world context, we performed a retrospective analysis assessing the efficacy of CDK4/6is in 195 patients who had previous exposure to CDK4/6i in a prior treatment line at our institution.

Phosphorylation-driven epichaperome assembly is a regulator of cellular adaptability and proliferation.

The intricate network of protein-chaperone interactions is crucial for maintaining cellular function. Recent discoveries have unveiled the existence of specialized chaperone assemblies, known as epichaperomes, which serve as scaffolding platforms that orchestrate the reconfiguration of protein-protein interaction networks, thereby enhancing cellular adaptability and proliferation. This study explores the structural and regulatory aspects of epichaperomes, with a particular focus on the role of post-translational modifications (PTMs) in their formation and function.

Predictors of Response to CDK4/6i Retrial After Prior CDK4/6i Failure in ER+ Metastatic Breast Cancer.

After disease progression on endocrine therapy (ET) plus a CDK4/6 inhibitor, there is no standardized sequence for subsequent treatment lines for estrogen receptor positive (ER+) metastatic breast cancer (MBC). CDK4/6i retrial as a treatment strategy is commonplace in modern clinical practice; however, the available prospective data investigating this strategy have had inconclusive results. To frame this data in a real-world context, we performed a retrospective analysis assessing the efficacy of CDK4/6is in 195 patients who had previous exposure to CDK4/6i in a prior treatment line at our institution.

Phosphorylation-Driven Epichaperome Assembly: A Critical Regulator of Cellular Adaptability and Proliferation.

The intricate protein-chaperone network is vital for cellular function. Recent discoveries have unveiled the existence of specialized chaperone complexes called epichaperomes, protein assemblies orchestrating the reconfiguration of protein-protein interaction networks, enhancing cellular adaptability and proliferation. This study delves into the structural and regulatory aspects of epichaperomes, with a particular emphasis on the significance of post-translational modifications in shaping their formation and function.

First-in-Human Evaluation of Site-Specifically Labeled Zr-Pertuzumab in Patients with HER2-Positive Breast Cancer.

Radioimmunoconjugates targeting human epidermal growth factor receptor 2 (HER2) have shown potential to noninvasively visualize HER2-positive tumors. However, the stochastic approach that has been traditionally used to radiolabel these antibodies yields poorly defined and heterogeneous products with suboptimal in vivo performance. Here, we describe a first-in-human PET study on patients with HER2-positive breast cancer evaluating the safety, biodistribution, and dosimetry of Zr-site-specific (ss)-pertuzumab PET, a site-specifically labeled radioimmunoconjugate designed to circumvent the limitations of random stochastic lysine labeling.

Trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2-expressing salivary gland carcinoma: a pooled analysis of two phase I studies.

Background: HER2-expressing salivary gland carcinoma (SGC) is associated with poor prognosis. Trastuzumab deruxtecan (T-DXd, DS-8201) has shown evidence of antitumor activity for several HER2-expressing solid tumors in multiple studies. This study aimed to present the efficacy and safety of T-DXd in patients with HER2-expressing SGC from a pooled analysis.

The HER2-directed antibody-drug conjugate DHES0815A in advanced and/or metastatic breast cancer: preclinical characterization and phase 1 trial results.

Approved antibody-drug conjugates (ADCs) for HER2-positive breast cancer include trastuzumab emtansine and trastuzumab deruxtecan. To develop a differentiated HER2 ADC, we chose an antibody that does not compete with trastuzumab or pertuzumab for binding, conjugated to a reduced potency PBD (pyrrolobenzodiazepine) dimer payload. PBDs are potent cytotoxic agents that alkylate and cross-link DNA.

Standard-of-care systemic therapy with or without stereotactic body radiotherapy in patients with oligoprogressive breast cancer or non-small-cell lung cancer (Consolidative Use of Radiotherapy to Block [CURB] oligoprogression): an open-label, randomised, controlled, phase 2 study.

Background: Most patients with metastatic cancer eventually develop resistance to systemic therapy, with some having limited disease progression (ie, oligoprogression). We aimed to assess whether stereotactic body radiotherapy (SBRT) targeting oligoprogressive sites could improve patient outcomes.

Methods: We did a phase 2, open-label, randomised controlled trial of SBRT in patients with oligoprogressive metastatic breast cancer or non-small-cell lung cancer (NSCLC) after having received at least first-line systemic therapy, with oligoprogression defined as five or less progressive lesions on PET-CT or CT.

Incidence of HER2-expressing brain metastases in patients with HER2-null breast cancer: a matched case analysis.

The HER2-directed antibody-drug conjugate trastuzumab deruxtecan is active against lower levels of HER2 expression than prior-generation therapies. The rate of HER2 expression in brain metastases among patients with initially HER2-null breast cancer is undefined, and receptor discordance in advanced breast cancer with brain metastases may underestimate CNS response potential in the absence of brain metastasis sampling. In this cohort study including 136 patients with 401 samples scored according to ASCO/CAP guidelines, 15/28 patients (54%) with HER2-null primary breast cancer have detectable HER2 expression in subsequently resected brain metastases, a significant discordant population.

Analytical and clinical validation of PATHWAY Anti-HER-2/neu (4B5) antibody to assess HER2-low status for trastuzumab deruxtecan treatment in breast cancer.

In DESTINY-Breast04 (DB-04), safety and efficacy of HER2-targeted antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) in previously treated HER2-low unresectable/metastatic breast cancer were established. This manuscript describes the analytical validation of PATHWAY Anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody (PATHWAY HER2 (4B5)) to assess HER2-low status and its clinical performance in DB-04. Preanalytical processing and tissue staining parameters were evaluated to determine their impact on HER2 scoring.

Pruritus related to trastuzumab and pertuzumab in HER2 + breast cancer patients.

Purpose: The combination of trastuzumab and pertuzumab (HP) as part of a taxane-based regimen has shown benefit in the adjuvant and metastatic HER2 + breast cancer setting. In the CLEOPATRA trial, pruritus was reported in 11-17.6% of patients.

Systems-level analyses of protein-protein interaction network dysfunctions via epichaperomics identify cancer-specific mechanisms of stress adaptation.

Systems-level assessments of protein-protein interaction (PPI) network dysfunctions are currently out-of-reach because approaches enabling proteome-wide identification, analysis, and modulation of context-specific PPI changes in native (unengineered) cells and tissues are lacking. Herein, we take advantage of chemical binders of maladaptive scaffolding structures termed epichaperomes and develop an epichaperome-based 'omics platform, epichaperomics, to identify PPI alterations in disease. We provide multiple lines of evidence, at both biochemical and functional levels, demonstrating the importance of these probes to identify and study PPI network dysfunctions and provide mechanistically and therapeutically relevant proteome-wide insights.

Targeting HER2-low in metastatic breast cancer: an evolving treatment paradigm.

The results of the Phase III DESTINY-Breast04 trial of trastuzumab deruxtecan (T-DXd) are leading to a shift in both the classification and treatment of human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. In this trial, T-DXd was associated with a substantial survival benefit among patients with hormone receptor-positive and hormone receptor-negative disease and low expression of HER2, a biomarker previously considered unactionable in this treatment setting. Herein, we discuss the evolving therapeutic pathway for HER2-low disease, ongoing clinical trials, and the potential challenges and evidence gaps arising with treatment of this patient population.