ERBB3 expression

PBX1, IGHM and CXCL13 are associated with the expression level of the ERBB3 and are prognostic markers for HER2-positive in BC, which may play an important role in the development and progression of BC.

The upregulation of GJB2 may serve as a prognostic biomarker, along with IL20RB, a known mediator of bone metastases. Furthermore, TDFP1 and ISL1 were identified as relevant transcription factors that could potentially regulate the biological processes in ROS1-rearranged NSCLC.

TFE3-RCC ARID2 KO cells demonstrated heightened sensitivity to the ERBB3 inhibitor AZD8931 compared to their wild-type counterparts, exhibiting significantly reduced migration and proliferation rates. These findings suggest that the PRCC-TFE3-ARID2-ERBB3 axis plays a critical role in TFE3-RCC pathogenesis and highlights the potential of targeting ERBB3 in ARID2-deficient TFE3-RCC as a therapeutic strategy. This study provides new insights into the molecular mechanisms of TFE3-RCC and suggests avenues for precision treatment of this aggressive cancer.

P2, N=121, Active, not recruiting, SCRI Development Innovations, LLC | Recruiting --> Active, not recruiting

Importantly, we found ER target gene transcription and promoter cofactor recruitment by tamoxifen can be reversed by induced miR205 expression. Altogether, miR-205 functions as a negative regulator of MED1 and HER3, affecting the regulation of the HER3-PI3K/Akt-MED1 axis in anti-estrogen resistance, and could serve as a potential therapeutic regime to overcome treatment resistance.

A high prevalence of HER3 expression was observed in pancreatic cancer patients after chemotherapy. Our findings indicate that HER3 is a potential therapeutic target for pancreatic cancer, deserving further clinical investigation.

Suppression of EMP3 expression enhanced sensitivity of BC cells to trastuzumab in vitro...Co‑expression of EMP3 and HER2 was positively associated with ER expression (P=0.028) and tended to be associated with nodal metastasis (P=0.085), however this was not significant. Taken together, the present results supported the potential of targeting EMP3 as a novel therapeutic strategy for human BC via co‑expression of HER2 and EMP3.

Inhibition of NRG1 in CAFs attenuated their impact on enzalutamide resistance, providing insight into the role of NRG1 in mediating the crosstalk between CAFs and prostate cancer in the context of enzalutamide resistance. This study elucidates the pivotal role of CAF-secreted NRG1 in promoting enzalutamide resistance in prostate cancer, providing valuable insights for developing targeted therapeutic strategies to overcome resistance in advanced prostate cancer.

The overexpression of ERBB2 or ERBB3 partially offset the anti-tumor effects of SD. Scleromitrion diffusum (Willd.) R. J. Wang inhibited gastric cancer growth and metastasis in vitro, which may be related to the inhibition of the ERBB2/ERBB3/PI3K/AKT pathway.

P1, N=388, Recruiting, Shanghai Chest Hospital; CSPC Megalith Biopharmaceutical Co., Ltd

The YAP-HER3 axis is crucial for the survival and adaptive resistance of high YAP-expressing RET-aberrant cancer cells treated with RET-TKIs. Combining YAP/HER3 inhibition with RET-TKIs represents a highly potent strategy for initial treatment.

The antitumor activity of HER3-DXd (10 mg/kg or 3 mg/kg dosed once weekly, 4 doses in total; Q1W x 4) was assessed in 30 BC PDX models (21 ER+/HER2- and 9 triple negative [TNBC]) and compared to the antitumor activity of the clinically approved TOP1 inhibitor irinotecan (50 mg/kg dosed once weekly; Q1W). HER3-DXd exerts a potent antitumor response in BC PDXs across baseline levels of HER3/ERBB3 expression in ER+/HER2- and TNBC models. Based on our data, basal-like PDX models were more likely to show long-term responses to HER3-DXd than luminal B PDX models. Results also suggest that BRCA1/2-altered PARPi-resistant tumors will show high benefit with HER3-DXd treatment.

This multifaceted approach could ultimately lead to more personalized treatment options for patients with HER3-positive breast cancers, thereby improving overall patient management and outcomes in this challenging disease landscape. This study presents recombinant affibodies tailored to bind to HER3 for cancer cell identification, along with novel methods for producing a range of affibody molecules.

Consistent with the initial results, HER3-ECD-targeting PAbs were cytotoxic in several human epithelial tumor cell lines and exerted antitumor effects in vivo. These results support the value of HER3 as a tumor antigen and the effector mechanisms of HER3-specific therapeutic MAbs, while suggesting the potential of the proposed vaccine candidate for the treatment of HER3-expressing carcinomas.

This study identified immunoregulatory protein expression according to HER3 status in breast cancer patients. As tumor with HER3 expression have more immunogenic microenvironment, investigating combination treatment of HER3 targeting agent and immunotherapy in HER3 expressing breast cancer may be promising.

P1/2, N=81, Recruiting, Cancer Research UK | N=135 --> 81

Treatment of mice with BxPC3 human pancreatic cancer xenografts showed that a combination of ZHER3-ABD-ZHER3-mcDM1 and its cytostatic analog ZHER3-ABD-ZHER3 was efficacious and superior to treatment with only ZHER3-ABD-ZHER3, providing tumor growth inhibition and longer median survival (90 d) in comparison to monotherapy (68 d) and vehicle control (49 d). ZHER3-ABD-ZHER3-mcDM1 was found to be a potent drug conjugate for the treatment of HER3-expressing tumors in mice.

P2, N=100, Recruiting, Medical College of Wisconsin | Not yet recruiting --> Recruiting

Simultaneously, numerous approaches to HER3 targeted therapy are enumerated, and the clinical detection methods for HER3 that are commonly employed in pathology are sorted and contrasted to offer physicians a range of options. We think that a better knowledge of the mechanisms underlying HER3 in tumors and the advancement of targeted HER3 therapy will contribute to an improved prognosis for cancer patients and an increase in the efficacy of anticancer therapies.

The study found that HER2 and HER3 biomarkers, which are targets for different therapies, are co-expressed in various types of cancer.

Membrane H-scores were calculated. Of 203 evaluable samples, HER3 expression was observed in 98.5%, including all histologies, genomic subtypes and regardless of prior systemic anticancer treatments. The median H-score was 140, and 70.4% had a HER3 intensity of 3+. HER3 is widely expressed in NSCLC, indicating that HER3-directed therapy may be broadly applicable across diverse subtypes of NSCLC.

We identified SON as a novel RNA splicing factor that plays a critical role in regulating ErbB2/3 expression, suggesting SON is an ideal therapeutic target in ErbB2-positive breast cancers.

P1, N=24, Recruiting, Herbert Lyerly | Trial completion date: Sep 2025 --> Jan 2026 | Trial primary completion date: Sep 2024 --> Jan 2025

P2, N=63, Active, not recruiting, MedSIR | Recruiting --> Active, not recruiting

High ERBB3 expression was associated with better survival. These data support the role of HER3 as a viable therapeutic target across multiple molecular subsets.

COS7 cells transiently transfected with the HER3-V104L mutation in the presence of HER binding partners showed higher expression of p-HER3, p-ERK1/2 versus HER3-WT in a NRG-independent manner without any change in AKT signaling. Overall, this study shows the clinical relevance of the HER3 V104L and the V104M mutations and its response to HER2, PI3K and ERK inhibitors.

P2, N=60, Recruiting, MedSIR | Trial primary completion date: Apr 2024 --> Dec 2025

P2, N=100, Not yet recruiting, Medical College of Wisconsin

P1, N=24, Recruiting, Herbert Lyerly | Trial completion date: Mar 2025 --> Sep 2025 | Trial primary completion date: Mar 2024 --> Sep 2024

Combination treatment with lorlatinib and erlotinib significantly reduced HRG1-induced activation of RTK signaling in ALK-positive NSCLC cells. HER3 overexpression has potential as a prognostic marker in ALK-positive NSCLCs, including ALK-TKI naïve and treated cases, especially those with EML4-ALK V1/V2. Assessing HER3 expression may be crucial for treatment planning and outcome prediction in these patients.

In patients with EGFR-mutated NSCLC after EGFR TKI and PBC, HER3-DXd treatment was associated with a clinically meaningful OS. The tumor biomarker characterization comprised the first description of potential mechanisms of resistance to HER3-DXd therapy.

In diverse CSPC patient populations, ERBB3 OE was associated with high AR signaling despite low intraprostatic androgen. Mechanistic studies demonstrated a direct link between HER3 and enzalutamide resistance. ERBB3 OE as a biomarker could thus stratify patients for intensification of therapy in castration-sensitive disease, including targeting HER3 directly to improve sensitivity to AR-targeted therapies.

Monoclonal antibodies such as lumretuzumab, seribantumab, and patritumab have shown potential in targeting HER3 to overcome resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Additionally, antibody-drug conjugates (ADCs) like HER3-DXd (patritumab deruxtecan) are new drug candidates that have demonstrated selective delivery of cytotoxic chemicals to NSCLC cells by exploiting HER3's widespread expression, minimizing cytotoxicity. This review aims to evaluate the efficacy of current HER3 therapeutics in development and their therapeutic potential in NSCLC, incorporating evidence from clinical trials.

P2, N=60, Recruiting, MedSIR | Not yet recruiting --> Recruiting

Considering the high cost of NGS, FISH remains a useful method for screening NRG1 fusions in various types of tumors. This study provides valuable insights into the molecular mechanisms of NRG1 fusion and identifies potential treatment targets for patients suffering from this disease.

HERTHENA-Lung02 is the first phase III trial to evaluate the safety and efficacy of HER3-DXd versus PBC in patients with progression on a third-generation EGFR TKI. Clinical Trial Registration: NCT05338970 (clinicaltrials.gov); 2021-005879-40 (EudraCT Number).

In diverse CSPC patient populations, ERBB3 OE was associated with high AR signaling and serum PSA despite low intraprostatic androgen, suggesting ERBB3 OE as a prospective biomarker for ligand-independent AR activation. In this context, ERBB3 OE could stratify patients for intensification of therapy in castration-sensitive disease and emphasizes the importance of biomarker-directed clinical trials with diverse populations.

In summary, we evaluated biomarkers for therapeutic targets using newly established PDX models of GAS. Frequent HER3 overexpression and HER2 expression in GAS tumors suggest the possibility of new treatments for patients with GAS by targeting HER3 and HER2.

In RAS wt mCRC patients receiving EGFR-targeted therapy, BRAF mutation is a powerful prognostic and therapy-predictive biomarker, with no effect found for PIK3CA mutation, PTEN mutation or deletion, but the combined biomarker KRAS/NRAS/BRAF/PIK3CA mutations predict resistance to anti-EGFR therapy. Low miR-31-3p expression may have positive prognostic and therapy predictive effects. Evidence on the prognostic and predictive roles of EGFR and its ligands, and HER2/3/4 is insufficient.

ErbB3 expression in human PDAC cell lines was similarly dependent on CtBP2 and depletion of ErbB3 in a human PDAC cell line severely attenuated growth, demonstrating the critical role of ErbB3 signaling in maintaining PDAC cell growth. Sensitivity to the ErbB2-targeted tyrosine kinase inhibitor lapatinib, but not the EGFR-targeted agent erlotinib, varied in proportion to the level of ErbB3 expression in mouse and human PDAC cells, suggesting that an ErBb2 inhibitor can effectively leverage CtBP2-driven transcriptional activation of physiologic ErbB2/3 expression and signaling in PDAC cells for therapeutic benefit.

We recently found that panobinostat and romidepsin potently induced TNBC cell growth inhibition and apoptosis via downregulation of HER3 through suppression of forkhead box protein A1 (FOXA1), a pioneering transcription factor...Notably, the combination of HDACis with an EGFR inhibitor (gefitinib) or an anti-HER3 antibody synergistically enhanced the anti-survival effects on BLBC cells... HDACis exhibit potent inhibitory effects on BLBC cells via downregulation of GATA2/3-mediated repression of FOXA1 gene transcription, which in turn suppresses HER3 expression and signaling. Our findings indicate that epigenetic targeting of the GATA2/3-FOXA1-HER3 axis may be an effective therapeutic strategy for the eradication of BLBC tumors.

We present novel metrics of HER2 heterogeneity via HDmIF, which offer detailed characterization of the diversity of HER2 expression in a large, clinically-annotated cohort with long-term follow-up. Identification of a strong association between immunophenotype and RFS supports further investigation of the highly immune activated subsets of ER-/HER2+ breast cancer. Strong correspondence of HER2 IF and IHC and our HAIQu methodology offers a pathway to translation of HER2het metrics to clinical practice.