HER2 expression status in diverse cancers: review of results from 37,992 patients

Monotherapy and combination therapy using antibody‑drug conjugates for platinum‑resistant ovarian cancer

Platinum‑resistant ovarian cancer (PROC) is a significant clinical challenge due to the limited number of treatment options and poor outcomes. Moreover, cytotoxic drugs have an unsatisfactory therapeutic efficacy, high toxicity and side effects. An antibody‑drug conjugate (ADC) is a novel cancer therapeutic strategy that combines an antibody, a linker and a payload. ADCs precisely target the tumor cells by binding to the antigen on the surface of tumor cells, thus accurately delivering the cytotoxic drugs and minimizing systemic toxicity. The approval of mirvetuximab soravtansine by the US Food and Drug Administration for treating folate receptor alpha‑positive, platinum‑resistant epithelial ovarian cancer has promoted studies on the use of ADCs in ovarian cancer. A phase III clinical trial showed that mirvetuximab soravtansine achieved an objective remission rate of 42.3% in platinum‑resistant, FRα‑positive ovarian cancer, compared with 15.9% using chemotherapy, demonstrating its immense potential for ADC development. The present review summarizes the research progress on the use of ADCs in PROC as a monotherapy and combination therapy and considers the future development direction of ADCs in PROC.

Precision oncology - Guideline of the Austrian, German and Swiss Societies for hematology and medical oncology

Precision oncology is a multi-step process including patient selection, tumor profiling, molecular tumor board discussion and personalized cancer management. So far, it remains largely unstandardized. The implementation of precision oncology can be beneficial for patients but implementation differs widely between tumor types and local practices. A working group was established by the Austrian, German and Swiss societies for Hematology and Medical Oncology to establish an expert consensus on evidence-based standards and implementation of precision oncology. Herein, we present a summary of this guideline. The full documents are available at www.onkopedia-guidelines.info.

Expression of HER2 in urothelial carcinoma and its significance

Objectives

We explored the expression levels and clinical significance of human epidermal growth factor receptor 2 (HER2) in urothelial carcinoma (UC) tissues.

Materials and methods

Patient data were reviewed, and 111 paraffin specimens of UC obtained from the Department of Urology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, from 2020 to 2021 were collected. Immunohistochemistry was used to detect HER2 protein expression in all UC tumor tissues. The χ 2 and Fisher exact tests were used to analyze the relationship between HER2 protein expression and clinicopathological data (sex, age, histopathological diagnosis, invasiveness, histopathological grade, maximum tumor diameter, muscle invasion, regional lymph node metastasis, and clinical stage).

Results

In this study, 92 cases (82.88%) showed HER2 protein expression, and there was a statistically significant difference in the distribution of HER2 positivity (immunohistochemistry 2+ and 3+) according to the pathological grades of UC (p = 0.021). Human epidermal growth factor receptor 2 positivity was not associated with sex, age, histopathological diagnosis, invasiveness, maximum tumor diameter, muscle invasion, regional lymph node metastasis, or clinical stage (all p < 0.05).

Conclusions

Human epidermal growth factor receptor 2 protein is highly expressed in UC, and its expression may be closely related to the high pathological grade of UC.

Unveiling HER2 immunoexpression in canine hepatoid gland neoplasms: clinicopathological and morphological associations

Canine hepatoid gland neoplasms (HGNs) are significant clinical concerns due to their high prevalence and diverse biological behaviour. Human epidermal growth factor receptor 2 (HER2), a tyrosine kinase receptor implicated in various aspects of tumorigenesis, has been extensively studied in human and animal neoplasms but remains unexplored in HGNs. This study aimed to assess HER2 immunoexpression in canine HGNs and its association with clinicopathological and morphological features. A total of 61 formalin-fixed paraffin-embedded samples, including normal hepatoid glands (n = 10), hepatoid gland adenomas (HGAs, n = 20), hepatoid gland epitheliomas (HGEs, n = 16), and hepatoid gland carcinomas (HGCs, n = 15), were analysed using immunohistochemistry. HER2 expression was scored based on percentage positivity and staining intensity. HER2-positive expression was detected in 50% of HGEs (score 2  +  ) and 73.3% of HGCs, with 36.4% of cases scoring 3   +   . In contrast, all HGAs and normal hepatoid tissues were HER2-immunonegative. Statistical analysis revealed significant differences in HER2 expression among normal and neoplastic hepatoid glands (p < 0.001). Only in HGCs, HER2 expression was significantly associated with tissue invasion (p = 0.007), mitotic count (p = 0.033), and nuclear pleomorphism (p = 0.007). These findings suggest that HER2 may play a role in the progression of malignant HGNs, particularly HGCs. This preliminary study highlights the potential of HER2 as a diagnostic marker and emphasizes the need for further investigation into its prognostic value and role in HER2-targeted therapy for canine HGCs.

The potential of chimeric antigen receptor -T cell therapy for endocrine cancer

Endocrine cancer, a relatively rare and heterogeneous tumor with diverse clinical features. The facile synthesis of hormones further complicates endocrine cancer treatment. Thus, the development of safe and effective systemic treatment approaches, such as chimeric antigen receptor (CAR) T cell therapy, is imperative to enhance the prognosis of patients with endocrine cancer. Although this therapy has achieved good results in the treatment of hematological malignancies, it encounters diverse complications and challenges in the context of endocrine cancer. This review delineates the generation of CAR-T cells, examines the potential of CAR-T cell therapy for endocrine cancer, enumerates pivotal antigens linked to endocrine cancer, encapsulates the challenges confronted with CAR-T cell therapy for endocrine cancer, and expounds upon strategies to overcome these limitations. The primary objective is to provide insightful perspectives that can contribute to the advancement of CAR-T cell therapy in the field of endocrine cancer.

Development and clinical evaluation of [68Ga]Ga-NODAGA-ADAPT6 as a novel HER2-targeted PET radiotracer for breast cancer imaging and treatment monitoring

PURPOSE

Accurate assessment of human epidermal growth factor receptor type 2 (HER2) expression is crucial for diagnosis, treatment planning, and monitoring of breast cancer patients. A 68Ga-labeled tracer based on the albumin-binding domain-derived affinity protein 6 (ADAPT6) was developed to evaluate HER2 expression in breast cancer.

METHODS

The gene encoding ADAPT6 was modified with N-terminal (GHEHEHEDANS) and C-terminal (GSSC) extensions to enhance its functionality. The precursor was synthesized, purified, and characterized, followed by radiolabeling with 68Ga to produce [68Ga]Ga-NODAGA-ADAPT6. In vivo metabolism and biodistribution studies were performed in HCC1954 (HER2-positive) and MDA-MB-468 (HER2-negative) tumor-bearing mice. Additionally, with ethical approval and informed consent, 22 breast cancer patients underwent [68Ga]Ga-NODAGA-ADAPT6 PET imaging to assess HER2 expression in primary and metastatic lesions.

RESULTS

The tracer was prepared with a radiochemical purity exceeding 99% and demonstrated high stability in vivo. Micro-PET/CT imaging revealed significant accumulation of the radiotracer in HCC1954 tumors, which was markedly reduced after HER2 blockade with trastuzumab. In contrast, MDA-MB-468 tumors showed minimal uptake. In the clinical study, [68Ga]Ga-NODAGA-ADAPT6 PET images displayed varying levels of radiotracer uptake in primary and metastatic lesions, which correlated well with the HER2 expression status determined by pathological analysis.

CONCLUSION

[68Ga]Ga-NODAGA-ADAPT6 exhibited excellent pharmacokinetic properties and high specificity for HER2-expressing lesions in PET imaging. These findings highlight its potential as a promising tool for distinguishing different levels of HER2 expression in breast cancer, aiding in personalized treatment strategies.

Affibody-based HER2 prodrug shows conditional cytotoxic effect on HER2-positive cancer cells

Therapeutic affinity proteins offer a targeted mode of action due to their typically high affinity and specificity for disease-associated molecules. In cancer therapy, such target molecules are often overexpressed receptors on tumor cells. However, their presence in healthy tissues can lead to on-target, off-tumor toxicity, necessitating strategies to enhance tumor selectivity. Here, we present an affibody-based prodrug concept that exploits tumor-associated proteases for selective activation. As proof of concept, we designed, produced, and characterized HER2-specific prodrug candidates, each incorporating a distinct protease substrate for selective activation by tumor-associated proteases. Their activation by corresponding proteases and subsequent HER2 binding were assessed. The most promising prodrug candidate was conjugated to the cytotoxic agent DM1 and evaluated for cytotoxicity in HER2-positive cancer cells. The results demonstrated potent, HER2-dependent cell killing, with markedly reduced cytotoxicity in the absence of prodrug activation. These findings support the feasibility of affibody-based prodrugs as a strategy to enhance tumor selectivity and minimize off-tumor toxicity in targeted cancer therapy.

Both complete response and long-term survival after combination therapy with toripalimab in a patient with meta-oligometastases cervical cancer: a case report

Background

The therapeutic landscape for recurrent or metastatic cervical cancer remains limited, with few options available. According to National Comprehensive Cancer Network (NCCN) guidelines, pembrolizumab combined with chemotherapy, with or without bevacizumab, is recommended for affected patients. Despite these guidelines, recurrence rates remain elevated, and survival outcomes following standard interventions are unsatisfactory. Furthermore, real-world management of recurrent or metastatic cervical cancer presents inherent complexities, often requiring an integrative, multidimensional treatment approach to enhance long-term survival. The pressing need to refine and adopt multimodal therapeutic strategies is evident in addressing the persistent challenges associated with disease recurrence and progression.

Case description

The case involved a 40-year-old female diagnosed with advanced cervical cancer who underwent radical hysterectomy. Postoperative pathology identified high-risk features, including lymph node involvement, necessitating adjuvant chemoradiotherapy. However, disease progression occurred during treatment, manifesting as metastases in the left supraclavicular and axillary lymph nodes. Subsequent local radiotherapy and systemic therapy led to a favorable response. By November 2024, overall survival (OS) had surpassed 72 months, with toripalimab administered for 65 months, during which no immunotherapy-related adverse events occurred.

Conclusion

This case offers clinical insight into the efficacy and safety of integrating chemotherapy, immunotherapy, and radiotherapy in recurrent or metastatic cervical cancer. The multimodal approach contributes to prolonged survival in this patient. Further clinical trials are essential to substantiate the therapeutic benefits of this regimen in broader patient cohorts.

A novel anti-HER2/EGFR bispecific antibody-drug conjugate demonstrates promising antitumor efficacy and overcomes resistance to HER2- or EGFR-targeted ADCs

HER2 and EGFR are frequently co-expressed in various tumors. While antibody-drug conjugates (ADCs) targeting HER2, such as T-DM1 and T-Dxd, have shown remarkable antitumor effects in clinical responses, their effectiveness is constrained by drug resistance. EGFR amplification or high expression is one of the factors that lead to resistance against HER2-targeted ADCs. Likewise, the amplification of HER2 may lead to the development of resistance to EGFR-targeted therapies. To overcome these challenges, we, therefore, developed a bispecific antibody (B2C4) that targets HER2 and EGFR. B2C4 exhibited strong binding affinity and internalization activity in tumor cells with high expression of HER2 and EGFR, as well as in those with high expression of either target. B2C4 was then conjugated with vc-MMAE to create a bispecific ADC (B2C4-MMAE) with an average DAR of 4.05. By effectively engaging both arms of the bispecific ADC, B2C4-MMAE demonstrated significant antitumor activity in tumor cells and animal models that were unresponsive HER2- or EGFR-targeted ADCs. B2C4-MMAE could serve as an alternative therapeutic option for tumors that are resistant to single-target treatments. Additionally, B2C4-MMAE exhibited potential in treating tumors resistant to T-Dxd, underscoring its promise as a treatment for challenging cases.

Distribution and concordance of HER2 scores in endometrial and ovarian cancer

OBJECTIVES

Although multiple HER2 scoring criteria exist, the optimal strategy to identify patients with gynecologic malignancies who may benefit from HER2-directed therapies remains unknown. The objectives of this study were to assess the distribution and concordance of HER2 scores in endometrial and ovarian cancer.

METHODS

One hundred five tumor specimens from 94 patients with endometrial or epithelial ovarian cancer (EOC) who underwent Caris tumor profiling from 11/2022 to 01/2025 were identified from a retrospective database. Each sample was assigned a HER2 immunohistochemistry (IHC) score of 0, 1+, 2+, or 3+ using breast, endometrial, and gastric criteria. ERBB2 amplification and HER2 IHC scores were abstracted from Caris reports. Patient characteristics and HER2 score distributions were analyzed using descriptive statistics and Fisher's exact test. Matrix correlation coefficients were used to assess HER2 score concordance.

RESULTS

A total of 105 samples underwent internal triplicate HER2 scoring - 63 EOC and 42 endometrial. A higher percentage of patients with endometrial cancer were HER2-high compared to those with EOC (45.2-50 % vs 20.6 %, p < 0.05). Internal triplicate HER2 score concordance was strong (r ≥ 0.96, p < 0.001) but weaker when compared to Caris scores (r = 0.66). Of the 23 discordant HER2 results, 13 would have changed therapy eligibility (56.5 %). Only 12 patients (12.7 %) had intermediate or high ERBB2 amplification.

CONCLUSIONS

A clinically significant percentage of patients had HER2-high tumors regardless of tumor type. HER2 score concordance was strong within each sample but weaker when compared to Caris scores. Incorporating multi-site testing and/or validation of external IHC into any gynecologic HER2 scoring algorithm should be considered.

A novel DNA sequence-selective, guanine mono-alkylating ADC payload suitable for solid tumour treatment

Pyridinobenzodiazepines (PDDs) are a new class of DNA mono-alkylating antibody-drug conjugate (ADC) payloads that can be linked through their C9 position to a sequence recognition component, guiding them to specific DNA sequences. Compound 18 is a PDD monomer with a unique sequence-selectivity profile and high cytotoxicity in vitro (e.g., IC50 = 0.30 nM in SW60; 1.6 nM in LIM1215 and 0.142 nM in SW48 cell line, after 96 hours incubation). To evaluate its potential as an ADC payload, an amine functionality was introduced into the terminal phenyl ring, and the modified compound was conjugated to trastuzumab (drug-antibody ratio [DAR] = 1.6). The resulting ADC exhibits significant in vivo efficacy in a pancreatic cancer xenograft model using BALB-c mice transplanted with the CAPAN-1 cell line. Complete tumour regression is observed out to 60 days after a single dose of 2 mg kg-1 comparing favourably to a 10 mg kg-1 dose of trastuzumab deruxtecan (Enhertu®). The novel ADC has a good tolerability profile, with a maximum tolerated dose (MTD) above 15 mg kg-1. The tolerability and efficacy profile of compound 18 in an ADC format suggests that PDDs represent a potentially valuable new class of payloads for the treatment of solid tumours.

Pan-Cancer Molecular Biomarkers: Practical Considerations for the Surgical Pathologist

Traditional anatomic pathologic classification of cancer is based on tissue of origin and morphologic and immunohistochemical characterization of the malignant cells. With the technological improvements of massively parallel or next-generation sequencing, oncogenic drivers that are shared across different tumor types are increasingly being identified and used as pan-cancer biomarkers. This approach is reflected in the growing list of Food and Drug Administration-approved tumor-agnostic therapies, including pembrolizumab in the setting of microsatellite instability and high tumor mutational burden, larotrectinib and entrectinib for solid tumors with NTRK fusions, and combined dabrafenib-trametinib for BRAF V600E-mutated neoplasms. Several other biomarkers are currently under investigation, including fibroblast growth factor receptor (FGFR), RET, and ROS1 fusions; ERBB2 amplification; and mutations in the AKT1/2/3, NF1, RAS pathway and (mitogen-activated protein kinase (MAPK) pathway. As molecular assays are increasingly incorporated into routine tumor workup, the emergence of additional pan-cancer biomarkers is likely to be a matter more of "when" than "if." In this review, we first explore some of the conceptual and technical considerations at the intersection of surgical and molecular pathology, followed by a brief overview of both established and emerging molecular pan-cancer biomarkers and their diagnostic and clinical applications.

New Gain-of-Function Mutations Prioritize Mechanisms of HER2 Activation

ERBB2 (HER2) is a well-studied oncogene with several driver mutations apart from the well-known amplification defect in some breast cancers. We used the GigaAssay to test the functional effect of HER2 missense mutations on its receptor tyrosine kinase function. The GigaAssay is a modular high-throughput one-pot assay system for simultaneously measuring molecular function of thousands of genetic variants at very high accuracy. The activities of 5,886 mutations were classified, significantly more than mutants previously reported. These variants include 112 new in vitro, 10 known, and 9 new in vivo gain-of-function (GOF) mutations. Many of the GOFs spatially cluster in sequence and structure, supporting the activation mechanisms of heterodimerization with EGFR and release of kinase inhibition by the juxtamembrane domain. Retrospective analysis of patient outcomes from the Genomic Data Commons predicts increased survival with the newly identified HER2 GOF variants.

A Checkpoint Reversal Receptor Mediates Bipartite Activation and Enhances CAR T-cell Function

SIGNIFICANCE

Enhancing CART function and persistence while balancing immune effector-mediated inflammation is crucial. Using our clinically relevant HER2-CAR platform, we demonstrate that tumor-intrinsic signals like the PD-1/PD-L1 immune checkpoint can be leveraged in CART design to modulate immune synapse and metabolic parameters, improving antitumor function without increasing cytokine production.

Tissue-Based Biomarkers Important for Prognostication and Management of Genitourinary Tumors, Including Surrogate Markers of Genomic Alterations

A better understanding of the molecular alterations that underlie urologic malignancies and advances in targeted therapies has impacted classification, prognostication, and treatment. In bladder tumors, these advances include the development of antibody-drug conjugates targeting nectin-4 and Trop-2, as well as human epidermal growth factor receptor 2 and immunotherapy. In prostate cancer, assessment of the percentage of Gleason pattern 4, presence of cribriform glands, and molecular alterations, including PTEN and mismatch repair protein loss, have become standard for clinical care. In renal malignancies, alterations in TSC1/2, mammalian target of rapamycin, anaplastic lymphoma kinase, and other genes impact classification and therapeutic decisions.

Treatment advances across the cervical cancer spectrum

Cervical cancer is preventable with screening and vaccination approaches; however, access to these preventative measures is limited both nationally and globally and thus many women will still develop cervical cancer. Novel treatments and practice-changing research have improved cervical cancer outcomes over the past few decades. In this Review, we discuss clinical trials that have refined or redefined the treatment of cervical cancers across the early stage, locally advanced, persistent, recurrent and/or metastatic disease settings. Advances for patients with early stage disease have been achieved through trials evaluating less extensive and fertility-preserving surgeries, different surgical approaches (open versus minimally invasive), and sentinel versus full pelvic lymph node dissection. We also discuss results from trials testing the use of neoadjuvant, induction and adjuvant chemotherapy as well as immune-checkpoint inhibitors in patients with locally advanced disease. Finally, we review the progress made with systemic chemotherapy and novel therapeutics, including anti-angiogenic agents, immune-checkpoint inhibitors and antibody-drug conjugates, in the setting of metastatic and/or recurrent cervical cancer. The advances highlighted in this manuscript have reduced morbidity and improved overall survival for patients with this challenging-to-treat disease, while also inspiring additional research and trials in the field.

HER2 expression in a molecularly defined cohort of endometrial cancer patients: The SPECTRUM study

BACKGROUND

HER2 antibody-drug conjugates like Trastuzumab deruxtecan (TDxd) have shown efficacy in HER2-low cancers, however the prevalence and clinical impact of HER2-low in endometrial cancer (EC) remains unclear. This study investigates HER2 expression in EC, focusing on HER2-low frequency, its distribution across histologic and molecular subtypes, intratumoral heterogeneity, and prognostic significance.

METHODS

This retrospective analysis included EC patients categorized histologically and molecularly, using ASCO/CAP HER2 scoring guidelines for endometrial, gastric, and breast cancers. The main aim was to determine HER2-low frequency by molecular subtype, with secondary goals of assessing HER2 heterogeneity, changes between primary and recurrent tumors, guidelines concordance and the impact of HER2 status on recurrence-free (RFS) and overall survival (OS).

RESULTS

193 EC patients were included, 111 low grade endometrioid EC and 82 high grade EC with various histotypes. Based on endometrial criteria, 69.9 % were HER2-negative, 25.8 % HER2-low, and 4.3 % HER2-positive, with HER2-low being most common in POLEmut (66.7 %) and p53abn (45.1 %) subtypes. Low heterogeneity in HER2 expression was observed between different tumors areas and between primary tumors and their recurrences. The endometrial and gastric criteria had high concordance (88.7 %), with endometrial guidelines detecting more HER2-low cases. Neither HER2-low nor HER2-positivity versus HER2-negativity had an impact on RFS or OS, with the stage at diagnosis being the only factor associated with survival, while age was associated only with OS.

CONCLUSIONS

This study highlights the distribution of HER2-low across EC molecular subtypes, with endometrial criteria proving more sensitive for identifying HER2-low cases, though HER2 status had no prognostic value in this cohort.

Selecting Targets for Molecular Imaging of Gastric Cancer: An Immunohistochemical Evaluation

PURPOSE

Tumor-targeted positron emission tomography (PET) and fluorescence-guided surgery (FGS) could address current challenges in pre- and intraoperative imaging of gastric cancer. Adequate selection of molecular imaging targets remains crucial for successful tumor visualization. This study evaluated the potential of integrin αvβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM) and human epidermal growth factor receptor-2 (HER2) for molecular imaging of primary gastric cancer, as well as lymph node and distant metastases.

METHODS

Expression of αvβ6, CEACAM5, EGFR, EpCAM and HER2 was determined using immunohistochemistry in human tissue specimens of primary gastric adenocarcinoma, healthy surrounding stomach, esophageal and duodenal tissue, tumor-positive and tumor-negative lymph nodes, and distant metastases, followed by quantification using the total immunostaining score (TIS).

RESULTS

Positive biomarker expression in primary gastric tumors was observed in 86% for αvβ6, 72% for CEACAM5, 77% for EGFR, 93% for EpCAM and 71% for HER2. Tumor expression of CEACAM5, EGFR and EpCAM was higher compared to healthy stomach tissue expression, while this was not the case for αvβ6 and HER2. Tumor-positive lymph nodes could be distinguished from tumor-negative lymph nodes, with accuracy ranging from 82 to 93% between biomarkers. CEACAM5, EGFR and EpCAM were abundantly expressed on distant metastases, with expression in 88-95% of tissue specimens.

CONCLUSION

Our findings show that CEACAM5, EGFR and EpCAM are promising targets for molecular imaging of primary gastric cancer, as well as visualization of both lymph node and distant metastases. Further clinical evaluation of PET and FGS tracers targeting these antigens is warranted.

Exploring Zanidatamab's efficacy across HER2-positive Malignancies: a narrative review

BACKGROUND

HER2-positive cancers involve amplification or overexpression of the HER2 gene, leading to aggressive tumor growth across several cancer types, including breast, gastric, ovarian, and pancreatic cancers. Detection methods such as immunohistochemistry, next-generation sequencing, and fluorescence in situ hybridization are used, with new advancements like biosensors and circulating tumor DNA offering improved diagnostic potential. Treatment strategies have evolved, including anti-HER2 drugs like trastuzumab and newer agents like zanidatamab, which show promise against HER2-positive malignancies.

METHODS

A comprehensive search of the following academic databases was performed including PubMed, Cochrane Library, and clinicaltrials.gov. A detailed search string was made. Studies were selected based on whether they contained the keywords and if they reported the details of treatment for zanidatamab. A total of 16 studies were selected. Abstracts were independently examined by one author and critically reviewed by another and if there were any conflicting viewpoints they were discussed until consensus was reached.

DISCUSSION

Zanidatamab has shown promising clinical outcomes in several HER2-positive cancers, including biliary tract, breast, gastric, and lung cancers, with high disease control rates and progression-free survival. Although it is not yet FDA-approved, it has received priority review for HER2-positive biliary tract cancer, with an FDA decision expected in November 2024. The safety profile of zanidatamab has been well-studied. The most common side effects include diarrhea, infusion reactions, and other mild to moderate treatment-related adverse events. In combination with Palbociclib for HER2-positive breast cancer, more severe side effects were observed, resulting in some patients discontinuing treatment. However, no treatment-related deaths have been reported across trials. While its anticancer efficacy and manageable safety profile are promising, long-term safety and efficacy data are still needed. Early clinical trials demonstrate strong efficacy, though some side effects, such as diarrhea and decreased ejection fraction, were noted. Future research should focus on understanding potential resistance mechanisms and establishing zanidatamab's broader role in the treatment landscape of HER2-positive cancers.

CONCLUSION

In summary, zanidatamab has shown significant tumor response, progression-free survival, disease control, and improved quality of life in early trials, however, the lack of long-term safety and efficacy data remains a key limitation, requiring further research.

HER2 amplification and HER2 low expression in endometrial carcinoma: prevalence across molecular, histological and clinicopathological risk groups

BACKGROUND

Emerging HER2-targeted therapies provide new treatment options for patients with HER2-expressing tumors. This study investigates the prevalence of HER2 amplification and HER2 low expression across a well-characterized cohort of endometrial carcinoma.

METHODS

HER2 chromogenic in situ hybridization (CISH) was used to detect HER2 amplification in endometrial carcinoma samples. Chromogenic HER2 immunohistochemistry (IHC) was performed. HER2 low was defined as IHC 1 + /2+ and negative CISH.

RESULTS

CISH confirmed HER2 amplification in 2% (n = 26) of the 1239 endometrial carcinoma samples including all the IHC 3+ cases (n = 13) and 20% of the 2+ cases (n = 55). Amplified cases presented various histotypes but consisted almost exclusively of p53 abnormal tumors. HER2 low 2+ category (n = 44) was heterogeneous with regard to molecular subgroup and histotype with 64.3% of the patients having high-risk disease. HER2 status did not independently predict disease-specific survival.

CONCLUSIONS

p53 abnormal molecular subgroup predicts HER2 amplification better than histotype. HER2 low cases present a wide range of histotypes and molecular subgroups including many patients with high-risk uterine cancer. Future trials of anti-HER2 therapies will clarify the clinical relevance of HER2 low status, treatment indications and guidelines for HER2 testing in endometrial carcinoma.

Phase I trial of the combination of the pan-ErbB inhibitor neratinib and mTOR inhibitor everolimus in advanced cancer patients with ErbB family gene alterations

BACKGROUND

The ErbB family of receptor tyrosine kinases are key targets for antitumor therapy. Although neratinib, a pan-ErbB kinase inhibitor, is approved in ErbB2-positive breast cancer, drug resistance is common. Preclinical data suggest that combining neratinib with the mTOR inhibitor everolimus may overcome such resistance.

PATIENTS AND METHODS

Our trial evaluated this combination's safety and efficacy in advanced cancers with ErbB alterations. We conducted a phase I dose-escalation trial of neratinib and everolimus. Primary objectives were to assess safety, tolerability, and dose-limiting toxicities (DLTs) and establish the maximum tolerated dose (MTD). Secondary objectives included objective response by RECIST v1.1 and pharmacokinetic analyses.

RESULTS

Twenty-two patients (median age 61, median of four prior therapies) with ErbB alterations (mutations 63.6%, amplification 36.3%, or ErbB2-overexpressed by immunohistochemistry 9.1%) were enrolled. Common tumor types included breast (31.8%), colorectal (18.2%), cervical (9.1%), and endometrial (9.1%) cancers. Frequent grade (G) 3 treatment-related adverse events were diarrhea (18.2%), anemia (9.1%), mucositis (9.1%), and acute kidney injury (9.1%). DLTs included G3 mucositis and diarrhea at dose level (DL) 5, and G3 increased creatinine at DL4. The MTD was DL4: neratinib 240 mg with everolimus 7.5 mg. The objective response rate was 19% with partial response in four patients. Stable disease ≥16 weeks was seen in two patients (9.5%), resulting in a clinical benefit rate of 28.6%.

CONCLUSION

Pharmacokinetic data indicated reduced neratinib clearance possibly due to CYP3A4 pathway saturation by everolimus. Combination therapy with neratinib and everolimus has a tolerable safety profile and clinical activity in ErbB-altered patients. ErbB family receptors and the PI3K pathway are commonly implicated in oncogenesis. This clinical study of neratinib and everolimus demonstrated favorable clinical activity and tolerability.

Comprehensive review of signaling pathways and therapeutic targets in gastrointestinal cancers

Targeted therapy, the milestone in the development of human medicine, originated in 2004 when the FDA approved the first targeted agent bevacizumab for colorectal cancer treatment. This new development has resulted from drug developers moving beyond traditional chemotherapy, and several trials have popped up in the last two decades with an unprecedented speed. Specifically, EGF/EGFR, VEGF/VEGFR, HGF/c-MET, and Claudin 18.2 therapeutic targets have been developed in recent years. Some targets previously thought to be undruggable are now being newly explored, such as the RAS site. However, the efficacy of targeted therapy is extremely variable, especially with the emergence of new drugs and the innovative use of traditional targets for other tumors in recent years. Accordingly, this review provides an overview of the major signaling pathway mechanisms and recent advances in targeted therapy for gastrointestinal cancers, as well as future perspectives.

Current Landscape of Molecular Biomarkers in Gastroesophageal Tumors and Potential Strategies for Co-Expression Patterns

The treatment of metastasized gastroesophageal adenocarcinoma largely depends on molecular profiling based on immunohistochemical procedures. Therefore, the examination of HER2, PD-L1, and dMMR/MSI is recommended by the majority of clinical practice guidelines, as positive expression leads to different treatment approaches. Data from large phase-III trials and consequent approvals in various countries enable physicians to offer their patients several therapy options including immunotherapy, targeted therapy, or both combined with chemotherapy. The introduction of novel therapeutic targets such as CLDN18.2 leads to a more complex decision-making process as a significant number of patients show positive results for the co-expression of other biomarkers besides CLDN18.2. The aim of this review is to summarize the current biomarker landscape of patients with metastatic gastroesophageal tumors, its direct clinical impact on daily decision-making, and to evaluate current findings on biomarker co-expression. Furthermore, possible treatment strategies with multiple biomarker expression are discussed.

Digestive cancers: mechanisms, therapeutics and management

Cancers of the digestive system are major contributors to global cancer-associated morbidity and mortality, accounting for 35% of annual cases of cancer deaths. The etiologies, molecular features, and therapeutic management of these cancer entities are highly heterogeneous and complex. Over the last decade, genomic and functional studies have provided unprecedented insights into the biology of digestive cancers, identifying genetic drivers of tumor progression and key interaction points of tumor cells with the immune system. This knowledge is continuously translated into novel treatment concepts and targets, which are dynamically reshaping the therapeutic landscape of these tumors. In this review, we provide a concise overview of the etiology and molecular pathology of the six most common cancers of the digestive system, including esophageal, gastric, biliary tract, pancreatic, hepatocellular, and colorectal cancers. We comprehensively describe the current stage-dependent pharmacological management of these malignancies, including chemo-, targeted, and immunotherapy. For each cancer entity, we provide an overview of recent therapeutic advancements and research progress. Finally, we describe how novel insights into tumor heterogeneity and immune evasion deepen our understanding of therapy resistance and provide an outlook on innovative therapeutic strategies that will shape the future management of digestive cancers, including CAR-T cell therapy, novel antibody-drug conjugates and targeted therapies.

Current status and innovative developments of CAR-T-cell therapy for the treatment of breast cancer

Breast cancer will overtake all other cancers in terms of diagnoses in 2024. Breast cancer counts highest among women in terms of cancer incidence and death rates. Innovative treatment approaches are desperately needed because treatment resistance brought on by current clinical drugs impedes therapeutic efficacy. The T cell-based immunotherapy known as chimeric antigen receptor (CAR) T cell treatment, which uses the patient's immune cells to fight cancer, has demonstrated remarkable efficacy in treating hematologic malignancies; nevertheless, the treatment effects in solid tumors, like breast cancer, have not lived up to expectations. We discuss in detail the role of tumor-associated antigens in breast cancer, current clinical trials, barriers to the intended therapeutic effects of CAR-T cell therapy, and potential ways to increase treatment efficacy. Finally, our review aims to stimulate readers' curiosity by summarizing the most recent advancements in CAR-T cell therapy for breast cancer.

Exploring lipidomic profiles and their correlation with hormone receptor and HER2 status in breast cancer

Dysregulated lipid metabolism promotes the progression of various cancer types, including breast cancer. The present study aimed to explore the lipidomic profiles of patients with breast cancer, providing insights into the correlation between lipid compositions and tumor subtypes characterized by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. Briefly, 30 patients with breast cancer were categorized into four groups based on their HR and HER2 status: HR+ no HER2 expression (HER2-0), HR+ HER2-low; HR+ HER2-positive (pos) and HR- HER2-pos. The lipidomic profiles of these patients were analyzed using high-throughput liquid chromatography-mass spectrometry. The data were processed through principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and random forest (RF) classification to assess the lipidomic variations and significant lipid features among these groups. The profiles of the lipids, particularly triglycerides (TG) such as TG(16:0-18:1-18:1)+NH4, were significantly different across the groups. PCA and PLS-DA identified unique lipid profiles in the HR+ HER2-pos and HR+ HER2-0 groups, while RF highlighted phosphatidylinositol-3,4,5-trisphosphate(21:2)+NH4 as a crucial lipid feature for accurate patient grouping. Advanced statistical analysis showed significant correlations between lipid carbon chain length and the number of double bonds within the classifications, providing insights into the role of structural lipid properties in tumor biology. Additionally, a clustering heatmap and network analysis indicated significant lipid-lipid interactions. Pathway enrichment analysis showed critical biological pathways, such as the 'Assembly of active LPL and LIPC lipase complexes', which has high enrichment ratio and statistical significance. In conclusion, the present study underscored that lipidomic profiling is crucial in understanding the metabolic alterations associated with different breast cancer subtypes. These findings highlighted specific lipid features and interactions that may serve as potential biomarkers for breast cancer classification and target pathways for therapeutic intervention. Furthermore, advanced lipidomic analyses can be integrated to decipher complex biological data, offering a foundation for further research into the role of lipid metabolism in cancer progression.

HER2-targeted ADC DX126-262 combined with chemotherapy demonstrates superior antitumor efficacy in HER2-positive gastric cancer

Gastric cancer is a common malignant tumor with high incidence and mortality. The overexpression of Human epidermal growth factor receptor 2 (HER2) is associated with increased metastatic potential and poor clinical outcome in gastric cancer. Despite the proven clinical response rates of approved HER2-targeted therapies, including Trastuzumab combined with chemotherapy, their limited long-term clinical benefits and inevitable disease progression still pose significant challenges to the clinical treatment of gastric cancer. Hence, exploring novel strategies to enhance therapeutic outcomes for HER2-positive patients is extremely crucial and urgent. Here, we reported that DX126-262, a novel HER2-targeted antibody-drug conjugate, generated by conjugating a potent Tubulysin B analogue (Tub-114) to humanized anti-HER2 monoclonal antibody, exhibited a significant synergistic inhibitory effect with both Cisplatin and 5-FU in HER2-positive gastric cancer NCI-N87 cells. Moreover, the triple-drug combination strategy of DX126-262 combined with Cisplatin and 5-FU showed much better in vitro and in vivo therapeutic efficacy than monotherapy or double-drug combination (Cisplatin plus 5-FU) or first-line standard-of-care (SOC, Herceptin plus Cisplatin and 5-FU), and comparable or even superior in vivo efficacy than third-line SOC (DS-8201a) in NCI-N87 cells and xenograft models. Meanwhile, the triple-drug combination therapy did not exhibit superimposed toxicity. Taken together, our findings provide compelling evidence that DX126-262 in combination with Cisplatin and 5-FU exerts synergistic antitumor activity and is a promising strategy to improve the clinical efficacy of HER2-positive advanced or metastatic gastric cancer.

HER2-Positive Serous Endometrial Cancer Treatment: Current Clinical Practice and Future Directions

The most common histological subtypes of endometrial cancer consist of endometrioid and uterine serous carcinoma, with the latter being more aggressive and accompanied by poor prognosis. Human epidermal growth factor receptor 2 (HER2) is a transmembrane tyrosine kinase receptor associated with cell proliferation, differentiation, and survival. HER2 positivity can be diagnosed in many solid tumors. It has been found that approximately one-third of the patients diagnosed with serous carcinoma may overexpress HER2/neu protein and/or show the amplification of the c-erBb2 gene. The prognostic and predictive value of HER2 biomarker is nowadays highlighted and the updates of HER2-directed treatment offer new opportunities for improved efficacy and survival. A number of HER2-targeted therapies have become available in recent years and have had promising results, prompting full drug approvals and additional investigation in many cancer types, among which is endometrial cancer. Data from clinical trials combining classical chemotherapy with anti-HER2 agents, mainly trastuzumab, alone or in combination with pertuzumab, do exist and have been incorporated into international guidelines. Moreover, further research with antibody-drug conjugates and tyrosine kinase inhibitors is being conducted. Acquired resistance remains an important problem, and its underlying mechanisms in endometrial cancer are mostly unknown. Studies exploring earlier use of Her2-directed therapy are also on the way. The purpose of this literature review is to describe the available therapies in the current clinical practice and the most prominent research data regarding the future. In any case, a number of unmet medical needs do exist for HER2-positive serous endometrial cancer, and additional research and studies are warranted to provide further understanding and improved outcomes for this tumor type.

Synthesis and biological assessment of chalcone and pyrazoline derivatives as novel inhibitor for ELF3-MED23 interaction

HER2 overexpression significantly contributes to the aggressive nature and recurrent patterns observed in various solid tumors, notably gastric cancers. Trastuzumab, HER2-targeting monoclonal antibody drug, has shown considerable clinical success; however, readily emerging drug resistance emphasizes the pressing need for improved interventions in HER2-overexpressing cancers. To address this, we proposed targeting the protein-protein interaction (PPI) between ELF3 and MED23 as an alternative therapeutic approach to trastuzumab. In this study, we synthesized a total of 26 compounds consisting of 10 chalcones, 7 pyrazoline acetyl, and 9 pyrazoline propionyl derivatives, and evaluated their biological activity as potential ELF3-MED23 PPI inhibitors. Upon systematic analysis, candidate compound 10 was selected due to its potency in downregulating reporter gene activity of ERBB2 promoter confirmed by SEAP activity and its effect on HER2 protein and mRNA levels. Compound 10 effectively disrupted the binding interface between the ELF3 TAD domain and the 391-582 amino acid region of MED23, resulting in successful inhibition of the ELF3-MED23 PPI. This intervention led to a substantial reduction in HER2 levels and its downstream signals in the HER2-positive gastric cancer cell line. Subsequently, compound 10 induced significant apoptosis and anti-proliferative effects, demonstrating superior in vitro and in vivo anticancer activity overall. We found that the anticancer activity of compound 10 was not only restricted to trastuzumab-sensitive cases, but was also valid for trastuzumab-refractory clones. This suggests its potential as a viable therapeutic option for trastuzumab-resistant gastric cancers. In summary, compound 10 could be a novel alternative therapeutic strategy for HER2-overexpressing cancers, overcoming the limitations of trastuzumab.

Molecular Biology of Cancer-Interplay of Malignant Cells with Emerging Therapies

Cancer is currently one of the leading causes of death worldwide, and according to data from the World Health Organization reported in 2020, it ranks as the second leading cause of death globally, accounting for 10 million fatalities [...].

Real-world evidence of Trastuzumab Deruxtecan (T-DXd) Efficacy in HER2-expressing gynecological malignancies

Human epidermal growth factor receptor 2 (HER2) overexpression emerges as an attractive therapeutic target in gynecological malignancies. Recently, Trastuzumab-Deruxtecan (T-DXd) has shown substantial efficacy in HER2 overexpressing carcinomas, most prominently in ovarian, endometrial and cervical patients. We have examined the efficacy of T-DXd in patients with metastatic endometrial, ovarian and cervical malignancies that were treated in the Department of Clinical Therapeutics, Alexandra Hospital, School of Medicine, National and Kapodistrian University of Athens.MethodsPatients with gynecological malignancies with HER2 expression 2 + /3 + as assessed by immunohistochemistry (IHC) that were treated with T-DXd were retrospectively identified. Patients received T-DXd intravenously at a dose of 5.4 mg/kg every 3 weeks until disease progression or unacceptable toxicity.ResultsIn total, 10 patients treated with T-DXd for recurrent/metastatic disease were identified. Regarding histology, there were 5 patients with uterine neoplasms (serous carcinoma (n = 3), uterine carcinosarcoma (n = 1), uterine leiomyosarcoma (n = 1)), 1 patient with squamous cervical carcinoma and 4 patients with ovarian cancer (ovarian carcinosarcoma (n = 2), high-grade serous carcinoma (n = 1) and mucinous ovarian carcinoma (n = 1)). Median age was 65.4 years (25th-75th percentile, 58.1-75.2 years). 5 patients had HER2 expression 3 + by IHC and 5 patients had HER2 expression 2 + . Median number of previous lines of therapy was 4 (range 2-6), 2 patients with uterine serous carcinoma were pretreated with trastuzumab and 4 patients had already received immunotherapy. In the entire cohort median progression-free survival (PFS) was 5.4 months (95%CI 0.8-9.8 months). Regarding responses, 5 patients had partial response (including 2 patients that were pretreated with trastuzumab), 1 patient had stable disease at 12 weeks and 4 patients had disease progression at initial assessment. All patients but one that derived clinical benefit had HER2 3 + expression.DiscussionIn the real-world setting, T-DXd showed activity in a cohort of heavily pre-treated patients with HER2-expressing gynecological malignancies.

[64Cu]Cu-NOTA-Trastuzumab and [89Zr]Zr-DFO-Trastuzumab in Xenografts with Varied HER2 Expression

Positron emission tomography (PET) has potential as a complementary technique to biomarker analysis, especially for human epidermal growth factor receptor 2 (HER2)-expressing tumors characterized by high heterogeneity. In this study, zirconium-89 (89Zr) and copper-64 (64Cu) labeled trastuzumab were employed to monitor varying levels of tumoral HER2 expression. Additionally, we studied the use of the cholesterol-depleting lovastatin as a pharmacological approach to enhance cell-surface HER2 expression in tumors with moderate to low HER2 levels, aiming to increase antibody accumulation in these tumor types. Both 89Zr- and 64Cu-labeled trastuzumab effectively monitor HER2 expression levels in xenografts exhibiting varying HER2 expression. No significant difference in tumor uptake was observed between 89Zr- or 64Cu-labeled trastuzumab, and tumor uptake for both radioimmunoconjugates positively correlated with HER2 protein levels. These findings underscore the potential of PET to monitor HER2 protein levels across heterogeneous tumors. Furthermore, our results suggest that further optimization of statin dosing and timing could offer a promising strategy to enhance trastuzumab accumulation in HER2-high, HER2-moderate, and HER2-low tumors.

Real-World Prevalence, Treatment Patterns, and Outcomes for Patients With HER2 (ERBB2)-Mutant Metastatic Non-Small Cell Lung Cancer, From a US-Based Clinico-Genomic Database

OBJECTIVES

Targeted therapies have been shown to improve outcomes in metastatic non-small cell lung cancer (mNSCLC) with driver mutations. We evaluated the real-world prevalence of human epidermal growth factor receptor 2 (HER2; ERBB2) tumor gene mutations among patients with mNSCLC and described historical treatments and outcomes in patients with HER2-mutant mNSCLC, during a period when there was no approved targeted therapy for HER2-mutant mNSCLC.

MATERIALS AND METHODS

This retrospective observational study used a US nationwide de-identified NSCLC clinico-genomic database. Eligible patients were adults diagnosed with HER2-mutant mNSCLC from January 2014 to July 2021 without co-occuring epidermal growth factor receptor (EGFR) tumor mutations. Descriptive statistics were used to summarize prevalence, baseline characteristics and treatment patterns. Clinical outcomes were estimated with Kaplan-Meier analyses.

RESULTS

Among 9206 patients with mNSCLC, 164 (1.78%) met the eligibility criteria (mean age: 67.3 years, 63.4% White, 56.7% female, and 53.0% with a smoking history). 132/164 (80.5%) had at least one line of treatment. Platinum-based chemotherapy (45.5%) and immune checkpoint inhibitor (ICI) with chemotherapy (28.0%) were the most frequently used first-line treatments. The median (95% confidence interval [CI]) real-world (rw) progression-free survival in first-line was 5.5 (4.8, 6.2) months and 3.0 (2.3, 4.2) months in second-line. The median rw overall survival in first-line was 13.2 (10.6, 18.4) months and 8.2 (6.6, 13.2) months in second-line.

CONCLUSION

During this study period, the most common regimens were platinum-based chemotherapy with or without ICI in first and second line, and median rwOS was 13.2 and 8.2 months, respectively. These results indicate the need for more effective targeted therapies in this patient population.

Targeted HER2-positive cancer therapy using ADAPT6 fused to horseradish peroxidase

Targeted cancer therapy is a promising alternative to the currently established cancer treatments, aiming to selectively kill cancer cells while sparing healthy tissues. Hereby, molecular targeting agents, such as monoclonal antibodies, are used to bind to cancer cell surface markers specifically. Although these agents have shown great clinical success, limitations still remain such as low tumor penetration and off-target effects. To overcome this limitation, novel fusion proteins comprised of the two proteins ADAPT6 and Horseradish Peroxidase (HRP) were engineered. Cancer cell targeting is hereby enabled by the small scaffold protein ADAPT6, engineered to specifically bind to human epidermal growth factor receptor 2 (HER2), a cell surface marker overexpressed in various cancer types, while the enzyme HRP oxidizes the nontoxic prodrug indole-3-acetic acid (IAA) which leads to the formation of free radicals and thereby to cytotoxic effects on cancer cells. The high affinity to HER2, as well as the enzymatic activity of HRP, were still present for the ADAPT6-HRP fusion proteins. Further, in vitro cytotoxicity assay using HER2-positive SKOV-3 cells revealed a clear advantage of the fusion proteins over free HRP by association of the fusion proteins directly to the cancer cells and therefore sustained cell killing. This novel strategy of combining ADAPT6 and HRP represents a promising approach and a viable alternative to antibody conjugation for targeted cancer therapy.

Trastuzumab Deruxtecan in Advanced Solid Tumors With Human Epidermal Growth Factor Receptor 2 Amplification Identified by Plasma Cell-Free DNA Testing: A Multicenter, Single-Arm, Phase II Basket Trial

PURPOSE

HERALD/EPOC1806 was conducted as a multicenter phase II trial assessing trastuzumab deruxtecan (T-DXd) therapy for patients with human epidermal growth factor receptor 2 (HER2)-amplified progressive stage solid tumors detected by cell-free DNA (cfDNA) testing.

PATIENTS AND METHODS

Patients exhibited advanced solid tumors with HER2 amplification that was identified via next-generation sequencing of cfDNA testing, without the requirement for immunohistochemical HER2 testing. The studied group was administered T-DXd at 5.4 mg/kg once every 3 weeks until onset of disease progression or intolerable toxicity.

RESULTS

Overall, 4,734 patients underwent cfDNA testing from December 2019 to January 2022, and 252 demonstrated HER2 amplification. Finally, the study included 62 patients with 16 cancer types with a median baseline plasma HER2 copy number (CN) of 8.55 (range, 2.4-73.9). Confirmed overall response rate (ORR) by investigator assessment was 56.5% (95% CI, 43.3 to 69.0), thus showing a value beyond the 5% threshold. Responses were evaluated for 13 cancer types, including KRAS-mutant colorectal (1/3), PIK3CA-mutant endometrial (5/6), and tissue HER2-negative gastric (1/2) cancers. Plasma HER2 CN above versus below the baseline median value did not differ for impact response; however, clearance of HER2 amplification in cfDNA on cycle 2 day 1 had higher response values compared with persistence. Median progression-free survival and response duration were 7.0 (95% CI, 4.9 to 9.7) and 8.8 (95% CI, 5.8 to 11.2) months, respectively, with the majority of complications being mild to moderate. Interstitial lung diseases were identified in 16 (26%) patients, including 14 patients with grade 1 disease, one patient with grade 2 disease, and one patient with grade 3 disease.

CONCLUSION

T-DXd treatment demonstrated high ORR with durable response in patients with advanced HER2-amplified solid tumors determined with cfDNA testing.

Trastuzumab-MMAU Antibody-Auristatin Conjugates: Valine-Glucoserine Linker with Stabilized Maleimide Conjugation Improves In Vivo Efficacy and Tolerability

Antibody-drug conjugates (ADC) have shown impressive clinical activity with approval of many agents in hematologic and solid tumors. However, challenges remain with both efficacy and safety of ADCs. This study describes novel trastuzumab-auristatin conjugates with the hydrophilic monomethylauristatin E (MMAE) prodrug MMAU, and optimization of a glycopeptide linker leading to a wider therapeutic window. Trastuzumab was conjugated with auristatin payloads via a series of linkers using a stabilized maleimide handle. The ADCs were characterized in vitro and their relative in vivo antitumor efficacies were assessed in HER2+ xenograft models. Relative linker stabilities and the mechanism of linker cleavage were studied using in vitro assays. Toxicity and toxicokinetics of the best performing ADC were evaluated in cynomolgus monkey (cyno). The trastuzumab-MMAU ADC with stabilized glycopeptide linker showed maleimide stabilization and higher resistance to cleavage by serum and lysosomal enzymes compared with a valine-citrulline conjugated trastuzumab ADC (trastuzumab-vc-MMAE). A single dose of 1 or 2 mg/kg of trastuzumab-MMAU at drug-to-antibody ratios (DAR) of eight and four respectively resulted in xenograft tumor growth inhibition, with superior efficacy to trastuzumab-vc-MMAE. Trastuzumab-MMAUDAR4 was tolerated at doses up to 12 mg/kg in cyno, which represents 2- to 4-fold higher dose than that observed with vedotin ADCs, and had increased terminal half-life and exposure. The optimized trastuzumab-MMAU ADC showed potent antitumor activity and was well tolerated with excellent pharmacokinetics in nonhuman primates, leading to a superior preclinical therapeutic window. The data support potential utility of trastuzumab-MMAU for treatment of HER2+ tumors.

Evaluation of a novel 177Lu-labelled therapeutic Affibody molecule with a deimmunized ABD domain and improved biodistribution profile

PURPOSE

Fusion of Affibody molecules with an albumin-binding domain (ABD) provides targeting agents, which are suitable for radionuclide therapy. To facilitate clinical translation, the low immunogenic potential of such constructs with targeting properties conserved is required.

METHODS

The HER2-targeting Affibody molecule ZHER2:2891 was fused with a deimmunized ABD variant and DOTA was conjugated to a unique C-terminal cysteine. The novel construct, PEP49989, was labelled with 177Lu. Affinity, specificity, and in vivo targeting properties of [177Lu]Lu-PEP49989 were characterised. Experimental therapy in mice with human HER2-expressing xenografts was evaluated.

RESULTS

The maximum molar activity of 52 GBq/µmol [177Lu]Lu-PEP49989 was obtained. [177Lu]Lu-PEP49989 bound specifically to HER2-expressing cells in vitro and in vivo. The HER2 binding affinity of [177Lu]Lu-PEP49989 was similar to the affinity of [177Lu]Lu-ABY-027 containing the parental ABD035 variant. The renal uptake of [177Lu]Lu-PEP49989 was 1.4-fold higher, but hepatic and splenic uptake was 1.7-2-fold lower than the uptake of [177Lu]Lu-ABY-027. The median survival of xenograft-bearing mice treated with 21 MBq [177Lu]Lu-PEP49989 (> 90 days) was significantly longer than the survival of mice treated with vehicle (38 days) or trastuzumab (45 days). Treatment using a combination of [177Lu]Lu-PEP49989 and trastuzumab increased the number of complete tumour remissions. The renal and hepatic toxicity was minimal to mild.

CONCLUSION

In preclinical studies, [177Lu]Lu-PEP49989 demonstrated favourable biodistribution and a strong antitumour effect, which was further enhanced by co-treatment with trastuzumab.

Histology Agnostic Drug Development: An Updated Review

Recent advancements in oncology have led to the development of histology-agnostic therapies, which target genetic alterations irrespective of the tumor's tissue of origin. This review aimed to provide a comprehensive update on the current state of histology-agnostic drug development, focusing on key therapies, including pembrolizumab, larotrectinib, entrectinib, dostarlimab, dabrafenib plus trametinib, selpercatinib, trastuzumab deruxtecan, and reprotrectinib. We performed a detailed analysis of each therapy's mechanism of action, clinical trial outcomes, and associated biomarkers. The review further explores challenges in drug resistance, such as adaptive signaling pathways and neoantigen variability, as well as diagnostic limitations in identifying optimal patient populations. While these therapies have demonstrated efficacy in various malignancies, significant hurdles remain, including intratumoral heterogeneity and resistance mechanisms that diminish treatment effectiveness. We propose considerations for refining trial designs and emerging biomarkers, such as tumor neoantigen burden, to enhance patient selection. These findings illustrate the transformative potential of histology-agnostic therapies in precision oncology but highlight the need for continued research to optimize their use and overcome existing barriers.

Identification of a central network hub of key prognostic genes based on correlation between transcriptomics and survival in patients with metastatic solid tumors

Background

Dysregulated pathways in cancer may be hub addicted. Identifying these dysregulated networks for targeting might lead to novel therapeutic options.

Objective

Considering the hypothesis that central hubs are associated with increased lethality, identifying key hub targets within central networks could lead to the development of novel drugs with improved efficacy in advanced metastatic solid tumors.

Design

Exploring transcriptomic data (22,000 gene products) from the WINTHER trial (N = 101 patients with various metastatic cancers), in which both tumor and normal organ-matched tissue were available.

Methods

A retrospective in silico analysis of all genes in the transcriptome was conducted to identify genes different in expression between tumor and normal tissues (paired t-test) and to determine their association with survival outcomes using survival analysis (Cox proportional hazard regression algorithm). Based on the biological relevance of the identified genes, hub targets of interest within central networks were then pinpointed. Patients were grouped based on the expression level of these genes (K-mean clustering), and the association of these groups with survival was examined (Cox proportional hazard regression algorithm, Forest plot, and Kaplan-Meier plot).

Results

We identified four key central hub genes-PLOD3, ARHGAP11A, RNF216, and CDCA8, for which high expression in tumor tissue compared to analogous normal tissue had the most significant correlation with worse outcomes. The correlation was independent of tumor or treatment type. The combination of the four genes showed the highest significance and correlation with the poorer outcome: overall survival (hazard ratio (95% confidence interval (CI)) = 10.5 (3.43-31.9) p = 9.12E-07 log-rank test in a Cox proportional hazard regression model). Findings were validated in independent cohorts.

Conclusion

The expression of PLOD3, ARHGAP11A, RNF216, and CDCA8 constitute, when combined, a prognostic tool, agnostic of tumor type and previous treatments. These genes represent potential targets for intercepting central hub networks in various cancers, offering avenues for novel therapeutic interventions.

HER2 Antibody-Drug Conjugates Are Active against Desmoplastic Small Round Cell Tumor

PURPOSE

Desmoplastic small round cell tumor (DSRCT) is a rare but highly aggressive soft tissue sarcoma that arises in the abdominopelvic cavity of young males. Since the discovery of EWSR1::WT1 fusion as the driver of DSRCT, no actionable genomic alterations have been identified, limiting disease management to a combination of surgery, chemotherapy, and radiation, with very poor outcomes. Herein, we evaluated ERBB2/HER2 expression in DSRCT as a therapeutic target.

EXPERIMENTAL DESIGN

ERBB2/HER2 expression was assessed in clinical samples and patient-derived xenografts (PDX) using RNA sequencing, RT-qPCR, and a newly developed HER2 IHC assay (clone 29D8). Responses to HER2 antibody-drug conjugates (ADC)-trastuzumab deruxtecan (T-DXd) and trastuzumab emtansine-were evaluated in DSRCT PDX, cell line, and organoid models. Drug internalization was demonstrated by live microscopy. Apoptosis was evaluated by Western blotting and caspase activity assays.

RESULTS

ERBB2/HER2 was detectable in DSRCT samples from patients and PDXs, with higher sensitivity RNA assays and improved IHC detectability using clone 29D8. Treatment of ERBB2/HER2-expressing DSRCT PDX, cell line, and organoid models with T-DXd or trastuzumab emtansine resulted in tumor regression. This therapeutic response was long-lasting in T-DXd-treated xenografts and was mediated by rapid HER2 ADC complex internalization and cytotoxicity, triggering p53-mediated apoptosis and growth arrest. Xenograft regression was associated with bystander payload effects triggering global tumor niche responses proportional to HER2 status.

CONCLUSIONS

ERBB2/HER2 is a therapeutic target in DSRCT. HER2 ADCs may represent novel options for managing this exceptionally aggressive sarcoma, possibly fulfilling an urgent and historically unmet need for more effective clinical therapy.

Cardiac toxicity of HER-2 targeting antibody-drug conjugates: overview and clinical implications

Antibody-drug conjugates (ADCs) have recently emerged as a promising therapeutic option that combine the specificity of monoclonal antibodies and the cytotoxic effect of chemotherapy. With numerous ADCs approved and on the market, a particular concern of ADCs that target HER-2 has been their cardiac side effects, in view of the crucial role of HER-2 in cardiac development and physiology. While rarely toxic and generally safe, numerous publications have outlined the consistent association of trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) with the development of cardiac toxicity. Despite not being clinically relevant in most cases, cardiac baseline evaluation, monitoring and early detection of cardiac adverse events remain pivotal with HER-2 targeting ADCs. This review aims to summarize and better characterize the complete cardiac toxicity profile of HER-2 ADCs, with the goal of improving clinical understanding of this adverse event, leading to better recognition, monitoring and management.

ADC: a deadly killer of platinum resistant ovarian cancer

Platinum is a key component of ovarian cancer systemic therapy. However, most patients will eventually face a recurrence, leading to chemotherapy resistance, especially against platinum. For individuals with platinum-resistant ovarian cancer (PROC), treatment options are limited, and their survival prospects are grim. The emergence of antibody-drug conjugates (ADCs) shows promises as a future treatment for PROC. This review synthesizes current research on the effectiveness of ADCs in treating PROC. It encapsulates the advancements and clinical trials of novel ADCs that target specific antigens such as Folate Receptor alpha (FRα), MUC16, NaPi2b, Mesothelin, Dipeptidase 3(DPEP3), and human epidermal growth factor receptor 2 (HER2), as well as tissue factor, highlighting their potential anti-tumor efficacy and used in combination with other therapies. The ADCs landscape in ovarian cancer therapeutics is swiftly evolving, promising more potent and efficacious treatment avenues.

Advances in HER2-Targeted Therapies: From monoclonal antibodies to dual inhibitors developments in cancer treatment

HER2 receptors, overexpressed in certain human cancers, have drawn significant attention in cancer research due to their correlation with poor survival rates. Researchers have developed monoclonal antibodies like Trastuzumab and Pertuzumab against HER2 receptors, which have proven highly beneficial in cancer therapy. Bispecific antibodies like Zanidatamab and antibody-drug conjugates like T-DM1 have been developed to overcome the resistance associated with monotherapy. Small molecules such as Lapatinib, Neratinib, and Pyrotinib were initially developed for treating breast cancer. However, ongoing research is investigating their potential use in other types of cancer, often in combination with other medications. EGFR/HER2 dual-targeted drugs have overcome drug resistance associated with HER2-targeted monotherapy. This comprehensive review covers the structural characteristics of HER2, the HER family signaling pathway mechanism, recent findings regarding HER2 receptor involvement in various cancers, and diverse HER2-targeted therapies. This information provides a comprehensive understanding of HER2-targeted strategies in the evolving field of cancer treatment.

Prognostic and Predictive Roles of HER2 Status in Non-Breast and Non-Gastroesophageal Carcinomas

The oncogene ERBB2, also known as HER2 or c-ERB2, is located on chromosome 17 (q12). It encodes a tyrosine kinase receptor, the human epidermal growth factor receptor 2 (HER2), involved in neoplastic proliferation, tumor angiogenesis, and invasiveness. Over the past years, the introduction of various anti-HER2 therapies has significantly improved outcomes for patients with HER2-positive breast and gastroesophageal carcinomas. More recently, the introduction of a new antibody-drug conjugate, that is trastuzumab deruxtecan, expanded the therapeutic options to low-HER2 breast and gastroesophageal tumors. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers. We critically analyzed the key published studies, focusing on utilized scoring systems and assays used, and analyzed clinical parameters and therapeutic approaches. Although the evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal has been widely increasing over the last decade, it still remains investigational, revealing a tumor site-related prognostic and predictive value of the different types of HER2 alterations. However, standardized and validated scoring system assays have not been well-established for many organs.

Trastuzumab, a monoclonal anti-HER2 antibody modulates cytotoxicity against cholangiocarcinoma via multiple mechanisms

Cholangiocarcinoma (CCA) is an aggressive and fatal cancer. The prognosis is very poor and no optimal chemotherapy has been established. Human epidermal growth factor receptor 2 (HER2, neu, and erbB2) is highly-expressed in breast cancer and is expressed in many other tumors but poorly expressed in CCA. The anti-HER2 antibody, trastuzumab, has been used for the treatment of HER2-positive breast and gastric cancer. In this study, we examined the surface expression of HER2 on seven Thai liver-fluke-associated CCA cell lines by flow cytometry, and found all of these CCA cells were weakly positive for HER2. MTT assay revealed that trastuzumab directly suppressed the growth of CCA. By using FcR-bearing recombinant Jurkat T-cell-expressing firefly luciferase gene under the control of NFAT response elements, we defined the activities of antibody-dependent cytotoxicity (ADCC) and antibody-dependent cell phagocytosis (ADCP). ADCC was confirmed by using expanded NK cells. ADCP was confirmed by using mouse peritoneal macrophages and human monocyte-derived macrophages as effector cells. Rabbit serum was administered to test the complement-dependent cytotoxicity (CDC) activity of trastuzumab. Finally, we evaluated the efficacy of trastuzumab in in vivo patient-derived cell xenograft and patient-derived xenograft (PDX) models. Our results showed that a distinct population of CCA (liver-fluke-associated CCA) expressed HER2. Trastuzumab demonstrated a potent inhibitory effect on even HER2 weakly positive CCA both in vitro and in vivo via multiple mechanisms. Thus, HER2 is a promising target in anti-CCA therapy, and trastuzumab can be considered a promising antibody immunotherapy agent for the treatment of CCA.

Criteria for assessing evidence for biomarker-targeted therapies in rare cancers-an extrapolation framework

Background

Advances in targeted therapy development and tumor sequencing technology are reclassifying cancers into smaller biomarker-defined diseases. Randomized controlled trials (RCTs) are often impractical in rare diseases, leading to calls for single-arm studies to be sufficient to inform clinical practice based on a strong biological rationale. However, without RCTs, favorable outcomes are often attributed to therapy but may be due to a more indolent disease course or other biases. When the clinical benefit of targeted therapy in a common cancer is established in RCTs, this benefit may extend to rarer cancers sharing the same biomarker. However, careful consideration of the appropriateness of extending the existing trial evidence beyond specific cancer types is required. A framework for extrapolating evidence for biomarker-targeted therapies to rare cancers is needed to support transparent decision-making.

Objectives

To construct a framework outlining the breadth of criteria essential for extrapolating evidence for a biomarker-targeted therapy generated from RCTs in common cancers to different rare cancers sharing the same biomarker.

Design

A series of questions articulating essential criteria for extrapolation.

Methods

The framework was developed from the core topics for extrapolation identified from a previous scoping review of methodological guidance. Principles for extrapolation outlined in guidance documents from the European Medicines Agency, the US Food and Drug Administration, and Australia's Medical Services Advisory Committee were incorporated.

Results

We propose a framework for assessing key assumptions of similarity of the disease and treatment outcomes between the common and rare cancer for five essential components: prognosis of the biomarker-defined cancer, biomarker test analytical validity, biomarker actionability, treatment efficacy, and safety. Knowledge gaps identified can be used to prioritize future studies.

Conclusion

This framework will allow systematic assessment, standardize regulatory, reimbursement and clinical decision-making, and facilitate transparent discussions between key stakeholders in drug assessment for rare biomarker-defined cancers.

Imaging CAR-NK cells targeted to HER2 ovarian cancer with human sodium-iodide symporter-based positron emission tomography

Chimeric antigen receptor (CAR) cell therapies utilize CARs to redirect immune cells towards cancer cells expressing specific antigens like human epidermal growth factor receptor 2 (HER2). Despite their potential, CAR T cell therapies exhibit variable response rates and adverse effects in some patients. Non-invasive molecular imaging can aid in predicting patient outcomes by tracking infused cells post-administration. CAR-T cells are typically autologous, increasing manufacturing complexity and costs. An alternative approach involves developing CAR natural killer (CAR-NK) cells as an off-the-shelf allogeneic product. In this study, we engineered HER2-targeted CAR-NK cells co-expressing the positron emission tomography (PET) reporter gene human sodium-iodide symporter (NIS) and assessed their therapeutic efficacy and PET imaging capability in a HER2 ovarian cancer mouse model.NK-92 cells were genetically modified to express a HER2-targeted CAR, the bioluminescence imaging reporter Antares, and NIS. HER2-expressing ovarian cancer cells were engineered to express the bioluminescence reporter Firefly luciferase (Fluc). Co-culture experiments demonstrated significantly enhanced cytotoxicity of CAR-NK cells compared to naive NK cells. In vivo studies involving mice with Fluc-expressing tumors revealed that those treated with CAR-NK cells exhibited reduced tumor burden and prolonged survival compared to controls. Longitudinal bioluminescence imaging demonstrated stable signals from CAR-NK cells over time. PET imaging using the NIS-targeted tracer 18F-tetrafluoroborate ([18F]TFB) showed significantly higher PET signals in mice treated with NIS-expressing CAR-NK cells.Overall, our study showcases the therapeutic potential of HER2-targeted CAR-NK cells in an aggressive ovarian cancer model and underscores the feasibility of using human-derived PET reporter gene imaging to monitor these cells non-invasively in patients.

Evaluation of HER2 immunohistochemistry expression in non-standard solid tumors from a Single-Institution Prospective Cohort

Aim

Human epidermal growth factor receptor-2 (HER2) is a well-established prognostic and predictive biomarker. It is an FDA-approved therapeutic target for HER2 positive breast, gastroesophageal, and more recently, lung and colon cancers. It is an emerging biomarker in biliary tract, bladder, cervical, endometrial, ovarian, and pancreatic cancers. The emergence of new indications warrants further characterization of HER2 expression in diverse cancer populations. This study investigated HER2 expression in solid tumour samples and the feasibility of obtaining these results.

Methods

Prospective consent was obtained at a Canadian tertiary academic cancer center from adult oncology patients who were referred for molecular genetic testing of malignant tissue samples. Standard HER2-targeted malignancies were considered breast and gastroesophageal, and were excluded from this study. Between July 2020 and November 2023, 499 samples of solid tumors underwent immunohistochemistry (IHC) HER2 staining. A median turnaround time (TAT) of 14 days would be considered feasible for clinical decision making.

Results

The mean age (± SD) of participants was 67 ± 12.5 years, with 270 (54%) male and 229 (46%) female. HER2 protein expression was measured in 42 unique cancer types. IHC levels of 0, 1+, 2+, and 3+ were reported and were 43%, 12%, 35%, and 10% of all analyzable samples respectively (tissue inadequate in 3% of samples). The median TAT for HER2 expression results from time of request to result in release was 18 (interquartile range, 11 to 30) days.

Conclusions

HER2 protein expression varies widely between different cancer types. TAT for HER2 IHC results was a median of 18 days, which is close to our feasibility cut-off.

HER2/ERBB2 overexpression in advanced gallbladder carcinoma: comprehensive evaluation by immunocytochemistry and fluorescence in situ hybridisation on fine-needle aspiration cytology samples

AIMS

Advanced gallbladder carcinoma (AGBC) carries a poor prognosis with dismal survival. There are no data regarding HER2/ERBB2 expression in AGBC. This study evaluated the overexpression of HER2/ERBB2 in cytological aspirates from AGBCs to identify potential patients for whom anti-HER2 targeted therapies can benefit.

METHODS

This prospective, case-control study was performed on 50 primary AGBC cases. A detailed cytomorphological assessment, followed by immunocytochemistry (ICC) for HER2/ERBB2, was performed on AGBC cell blocks. A similar number of age-matched and gender-matched resected chronic cholecystitis specimens were included as controls. Fluorescence in situ hybridisation (FISH) was performed in equivocal cases.

RESULTS

A total of 10 (20%) cases showed positive (3+), 19 (38%) equivocal (2+) expression and 21 (42%) were negative on HER2/ERBB2 ICC. None of the equivocal cases demonstrated HER2 amplification by FISH. Among the controls, none showed positive (3+) immunoexpression, 23 (46%) demonstrated equivocal expression and 27 (54%) were negative. On statistical analysis, HER2/ERBB2 overexpression was significantly associated with AGBC compared with the controls. Of all the clinical, radiological and cytomorphological parameters, the predominant papillary or acinar arrangements of the tumour cells were significantly associated with HER2/ERBB2 overexpression.

CONCLUSIONS

This is the first study to evaluate the expression of HER2/ERBB2 on cytological aspirates in AGBC using ICC and FISH. HER2/ERBB2 overexpression(20%) was significantly associated with AGBC. Furthermore, predominant papillary or acinar arrangements of tumour cells in the cytological smears were significantly associated with HER2/ERBB2 overexpression. They can serve as potential predictors of HER2/ERBB2 overexpression to select AGBC patients for anti-HER2 targeted therapies.