Discovery and development of pyrotinib: A novel irreversible EGFR/HER2 dual tyrosine kinase inhibitor with favorable safety profiles for the treatment of breast cancer

Targeting exon mutations in NSCLC: clinical insights into LAG-3, TIM-3 pathways, and advances in fourth-generation EGFR-TKIs

Lung cancer remains the second leading cause of cancer-related morbidity and mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become the standard first-line therapy for advanced NSCLC with EGFR mutations, offering significant improvements in progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) compared to chemotherapy alone. Recent studies suggest that their effectiveness decreased with the emergence of acquired resistance, such as C797S and T790M. Immunotherapy alone also shows enhanced PFS and OS over chemotherapy; however, its applicability can be limited in cases with low programmed cell death ligand 1 (PD-L1) expression and result in immune-related adverse effects like those observed in retrospective, non-randomized studies. Emerging fourth-generation EGFR-TKIs, currently under clinical trials, show promising potential to address these resistance mechanisms. Advanced inhibitors, including BBT-176, BLU-945, and BLU-701, have effectively targeted resistant mutations and reduced disease progression. Studies have suggested that combining fourth-generation EGFR-TKIs with immunotherapies targeting novel pathways like LAG-3 and TIM-3 may enhance patient outcomes. Such combination regimens aim to optimize PFS, OS, and ORR while minimizing adverse effects and addressing the limitations of current therapies. This study explores the landscape of EGFR mutations, their clinical significance, and the integration of innovative fourth-generation EGFR-TKIs with immunotherapies, emphasizing the potential of precision medicine in advancing the management of EGFR-mutated NSCLC.

HER2-targeted therapies: Unraveling their role in biliary tract cancers

Biliary tract cancers (BTCs) constitute a heterogeneous group of malignancies with rising incidence and limited therapeutic options in advanced stages, leading to increased overall mortality. Extensive genomic profiling has identified key oncogenic drivers in BTCs that represent promising therapeutic targets and could change the treatment paradigm. Evidence suggests improved survival outcomes for patients with actionable molecular alterations who received matched targeted therapies. Human epidermal growth factor receptor 2 (HER2) is a receptor tyrosine kinase and proto-oncogene that has been extensively studied as a prognostic biomarker and a therapeutic target in multiple solid organ malignancies. Recent clinical trials on the combination of trastuzumab with tucatinib, FOLFOX, or pertuzumab for previously treated, HER2-positive, advanced BTCs have shown improved outcomes compared to current second-line therapies. Early evidence from observational studies on trastuzumab-containing regimens as first-line suggests promising efficacy. Furthermore, the recent tumor-agnostic approval of trastuzumab deruxtecan for HER2-positive solid tumors has formally introduced HER2-directed agents in the BTC therapeutic arsenal. This review aims to summarize the rapidly evolving landscape of HER2-directed agents for BTCs, highlighting current evidence of survival benefit. Beginning with a concise presentation of the structural and functional aspects of HER2, we detail the frequency and prognostic significance of HER2 alterations in BTCs and discuss all available preclinical and clinical data on anti-HER2 agents tested for BTCs.

Recent advances in regulating the cell cycle through inhibiting CDKs for cancer treatment

The inhibition of cyclin-dependent kinases (CDKs) is considered a promising strategy for cancer treatment due to their role in cell cycle regulation. However, CDK inhibitors with no selectivity among CDK families have not been approved. A CDK inhibitor with high selectivity for CDK4/6 exhibited significant treatment effects on breast cancer and has become a heavy bomb on the market. Subsequently, resistance gradually decreased the efficacy of selective CDK4/6 inhibitors in breast cancer treatment. In this review, we first introduce the development of selective CDK4/6 inhibitors and then explain the role of CDK2 activation in inducing resistance to CDK4/6 inhibitors. Moreover, we focused on the development of CDK2/4/6 inhibitors and selective CDK2 inhibitors, which will aid in the discovery of novel CDK inhibitors targeting the cell cycle in the future.

Pyrotinib-assisted whole brain radiotherapy alleviates HER2-positive advanced breast cancer and brain metastases: a prospective study in patients

Purpose

The whole-brain radiotherapy (WRBT)-based therapeutic efficacy is often limited against human epidermal growth factor receptor 2 (HER2+)-positive advanced breast cancer (BC) and brain metastases (BM), requiring more effective treatment options. This prospective study evaluates the effectiveness and safety of combining WBRT with pyrotinib in patients with HER2+ advanced BC and BM.

Methods

The enrolled patients (n = 26, from April 2019 to March 2022) were divided into two treatment groups. Group 1 (p-WBRT) received pyrotinib initially, followed by subsequent WBRT. Group 2 (WBRT-p) received WBRT concurrently with pyrotinib. The intracranial progression-free survival (iPFS) was determined.

Results

In the WBRT-p group (n = 11), the median iPFS was recorded as 25.0 months (95% CI, 15.3-34.7), while the overall survival (OS) rates in 1-4 years were 100, 54.5, 9.1, and 0%, respectively. The intracranial objective response rate (iORR) and intracranial clinical benefit rate (iCBR) were 63.6 and 90.9%, respectively. In the p-WBRT group (n = 15), the median iPFS was around 22.0 months (95% CI, 4.3-39.7), and the OS rates in 1-4 years were 100, 53.3, 33.3, and 6.7%, respectively. The iORR and iCBR values were 66.7 and 80.0%, respectively. Notably, no significant differences in iPFS, OS, iORR, and iCBR were observed between treatment groups. Although some instances of adverse events, such as vomiting and reduced white blood cells and neutrophil counts, were evident, these adverse events were grades 1-3.

Conclusion

WBRT combined with pyrotinib exhibited exceptional tolerability, showing long iPFS in patients with HER2+ advanced BC and BM.

The Role of the Fox Gene in Breast Cancer Progression

Forkhead box (FOX) genes are a family of transcription factors that participate in many biological activities, from early embryogenesis to the formation of organs, and from regulation of glucose metabolism to regulation of longevity. Given the extensive influence in the multicellular process, FOX family proteins are responsible for the progression of many types of cancers, especially lung cancer, breast cancer, prostate cancer, and other cancers. Breast cancer is the most common cancer among women, and 2.3 million women were diagnosed in 2020. So, various drugs targeting the FOX signaling pathway have been developed to inhibit breast cancer progression. While the role of the FOX family gene in cancer development has not received enough attention, discovering more potential drugs targeting the FOX signaling pathway is urgently demanded. Here, we review the main members in the FOX gene family and summarize their signaling pathway, including the regulation of the FOX genes and their effects on breast cancer progression. We hope this review will emphasize the understanding of the role of the FOX gene in breast cancer and inspire the discovery of effective anti-breast cancer medicines targeting the FOX gene in the future.

Development of a risk prediction nomogram model of pyrotinib-induced severe diarrhea

BACKGROUND

To identify the factors influencing pyrotinib-induced severe diarrhea and to establish a risk prediction nomogram model.

METHODS

The clinical data of 226 patients received pyrotinib from two medical institutions from January 2019 to December 2023 were analysed retrospectively. A training set was made up of 167 patients from Hainan Cancer Hospital, and the external validation set was made up of 59 patients from Hainan West Central Hospital. Univariate and multivariate logistic regression analysis were used to identify independent factors influencing pyrotinib-induced severe diarrhea, and a risk prediction nomogram model was constructed, which was verified on patients in the external validation set.

RESULTS

History of adverse reactions (ADRs), initial dose of pyrotinib, combination with capecitabine, thrombocytopenia, aspartate transaminase (AST), and use of probiotics or other drugs that regulate the gut microbiota were identified as independent influencing factors for pyrotinib-induced severe diarrhea (all P < 0.05). Based on these, a risk prediction nomogram model of pyrotinib-induced severe diarrhea was established. The area under the receiver operating characteristic curve was 0.794 and 0.863 in the training set and the external validation set, respectively. The calibration curve of the prediction model displayed good consistency both the two sets, which indicated that the model could have favourable predictive ability.

CONCLUSION

The risk prediction nomogram model of pyrotinib-induced severe diarrhea constructed in this study may identify high risk populations earlier so that clinicians can make appropriate decisions in time.

An exploration of the optimal combination chemotherapy regimen based on neoadjuvant therapy containing pyrotinib for HER2-positive breast cancer: A multicenter real-world study

BACKGROUND

The combination of pyrotinib (Py) with cytotoxic agents proved to be effective in early human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). However, the optimal chemotherapy regimen is unknown. This study attempts to explore it from real-world research data.

METHODS

Information was collected from patients with early-stage HER2-positive BC from 23 centers across the country. They were categorized into the anthracycline group (A group) and non-anthracycline group (non-A group). Patients in the non-A group were further categorized into the platinum group and non-platinum group and the short-cycle (≤4 cycles) taxane group and long-cycle (>4 cycles) taxane group. Total pathological complete response (tpCR, ypT0/is ypN0) and breast pathological complete response (bpCR, ypT0/is) rates were assessed.

RESULTS

A total of 107 patients were enrolled. Postoperative pathology indicated a tpCR rate of 36.8 %, a bpCR rate of 42.1 % in the A group, the non-A group had a tpCR rate of 47.8 %, and a bpCR rate of 53.6 %, with P-values of 0.273 and 0.254, respectively. In the long-cycle taxane group, the tpCR and bpCR rates were 60.8 % and 66.7 %, respectively. In the short-cycle taxane group, the tpCR and bpCR rates were 11.1 % and 16.7 %, respectively (both P<0.001). The platinum group had higher tpCR rate (62.9 % vs. 32.4 %, respectively; P = 0.011) and bpCR rate (65.7 % vs. 41.2 %, respectively; P = 0.041).

CONCLUSION

As for a neoadjuvant therapy regimen with Py, an anthracycline-free regimen is feasible. Besides, platinum-containing, long-cycle taxane regimens appear to achieve superior efficacy under anthracycline-removed conditions.

Combined pyrotinib and fulvestrant for hormone receptor-positive and HER2-positive metastatic breast cancer: A multicenter, single-arm, phase II trial

This multicenter, single-arm, phase II clinical trial (NCT04034589) evaluated the efficacy and safety of pyrotinib combined with fulvestrant in patients with HR-positive/HER2-positive metastatic breast cancer who had experienced trastuzumab treatment failure. A total of 46 patients were enrolled, receiving pyrotinib orally once daily and fulvestrant intramuscularly on days 1 and 15 of cycle 1, followed by monthly doses on day 1. The primary endpoint was progression-free survival (PFS), while secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. The median PFS was 18.2 months (95% CI, 11.9-31.1) overall, 19.5 months (95% CI, 10.6-NA) for those receiving the combination as first-line therapy, and 18.4 months (95% CI, 16.7-NA) for patients with brain metastases. Median OS was not reached, with a 3-year OS rate of 75.2% (95% CI, 62.8-90.2%). The ORR was 32.5%, and the DCR was 97.5%. Responses were observed in patients with low tumor mutation burden and ZNF217 mutation. Importantly, no grade 4 or higher treatment-related adverse events or deaths were reported, indicating a favorable safety profile. In conclusion, the combination of pyrotinib and fulvestrant demonstrated promising antitumor activity and acceptable safety in HR-positive/HER2-positive metastatic breast cancer patients.

Epidermal growth factor receptor mutations in breast Cancer: Therapeutic challenges and way forward

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK) that is upregulated in aggressive triple-negative breast cancer (TNBC). Ligands such as EGF, TGF-α, epigen, and amphiregulin activate the auto-phosphorylation activity of tyrosine residues on EGFR, which regulates the growth, proliferation, adhesion, migration, and survival of cancer cells. Our prior studies depicted that inhibition of EGFR modulates the chemosensitivity in breast cancer stem cells and, thus, serves as a potent therapeutic target in breast cancer. Small-molecule tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs) specifically targeting EGFR have been clinically approved for breast cancer treatment. However, intrinsic and acquired resistance generated due to EGFR mutations limits the applications of designed EGFR-TKIs in breast cancer patients. This review highlights the therapeutic approaches, and the challenges encountered in targeting EGFR-specific mutations. It suggests the need to develop more advanced higher-generation inhibitors for use in combinatorial therapy along with chemo-or-immune therapeutics in clinics as a breast cancer treatment strategy against relapse of the disease.

Pyrotinib Plus Taxanes or Vinorelbine for the Treatment of Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer: Prospective Evaluation of Efficacy and Safety

PURPOSE

The clinical benefits of pyrotinib plus taxanes or vinorelbine have not been studied systemically. Consequently, we conducted a prospective evaluation to assess the efficacy and safety of pyrotinib plus taxanes or vinorelbine in patients with human epidermal growth factor 2 (HER2)-positive metastatic breast cancer (MBC).

METHODS

Patients with HER2-positive MBC were included to receive pyrotinib combined with taxanes or vinorelbine in Jiangsu Cancer Hospital. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), and adverse effects (AEs).

RESULTS

Between December 22, 2020 and January 11, 2023, a total of 101 patients were assigned to pyrotinib plus taxanes (n = 83) and pyrotinib plus vinorelbine (n = 18) groups. As of May 24, 2023, the median PFS for all patients was 11.5 months (95% confidence interval [CI], 8.8-15.7). The median PFS was significantly longer in pyrotinib plus taxanes group than in pyrotinib plus vinorelbine group (median PFS, 12.2 months [95% CI, 9.2-18.6] vs. 8.4 months [95% CI, 5.5-13.7]; P = .005). All the treatment-related side effects were tolerated. The most frequent grade 3 or 4 side effects included diarrhea (22.8%), leukopenia (19.5%), and neutropenia (18.2%).

CONCLUSION

Pyrotinib plus taxanes could be an alternative or even the preferred treatment strategy for patients with HER2-positive MBC after trastuzumab and small-molecule tyrosine kinase inhibitors (TKIs). We also suggest that pyrotinib combined with vinorelbine has a therapeutic potential.

REGISTRATION

This trial was registered in Chinese Clinical Trial Registry. URL: https://www.chictr.org.cn/showproj.html?proj=65697 (ChiCTR2000041217).

Pyrotinib and trastuzumab combination treatment synergistically overcomes HER2 dependency in HER2-positive breast cancer: insights from the PHILA trial

BACKGROUND

The PHILA study suggests that pyrotinib, trastuzumab, and docetaxel significantly improved progression-free survival (PFS) compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2-positive metastatic breast cancer. In this study, we aimed to investigate the synergistic mechanisms of pyrotinib plus trastuzumab and provide further insights for the PHILA trial.

METHODS

The in vitro activity of combination treatments was assessed through cell biological and biochemical experiments. The in vivo efficacy was evaluated in cell-derived xenografts, a TUBO tumour model, and one clinical case. Next-generation sequencing was performed on circulating tumour DNA (ctDNA) from patients in the PHILA trial.

FINDINGS

The combination of pyrotinib and trastuzumab more effectively inhibited cell growth than pyrotinib or trastuzumab alone in models of HER2-dependent breast cancer. It potentiated membrane HER2 ubiquitination and downregulation, which resulted in a comprehensive blockade of the HER2 signalling pathway. The pyrotinib-altered membrane HER2 levels had no significant effect on trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity (ADCC). We further validated the synergistic mechanisms in TUBO tumours and one clinical case, rather than models of HCC1954 cells harbouring the PIK3CA H1047R mutation. Similarly, in our centre cohort of the PHILA study, patients with genetic alterations in the HER2 signalling cascade had significantly shorter median PFS than individuals with the wild-type pathway.

INTERPRETATION

Our findings underscore the robust synergy between pyrotinib and trastuzumab in overcoming HER2 dependency and provide a rationale for pyrotinib, trastuzumab, and docetaxel as one of the optimal choices for patients with untreated HER2-positive metastatic breast cancer, who are dependent on the HER2 signalling cascade.

FUNDING

This work was supported by the National Key Research and Development Program of China (2021YFF1201300), the National Natural Science Foundation of China (82172875), the CAMS Innovation Fund for Medical Sciences (CIFMS) (2022-I2M-2-001), and the Joint Innovative Fund of Beijing Natural Science Foundation and Changping District (L234004).

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

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

Efficacy and Safety of Neoadjuvant Pyrotinib for Human Epidermal Receptor 2-Positive Breast Cancer: A Meta-Analysis

Neoadjuvant pyrotinib shows the potential to improve treatment response in human epidermal receptor 2 (HER2)-positive breast cancer patients, but relevant meta-analyses are scarce. This meta-analysis intended to explore the efficacy and safety of neoadjuvant pyrotinib for HER2-positive breast cancer patients. Studies comparing the efficacy and safety between HER2-positive breast cancer patients receiving pyrotinib-containing neoadjuvant treatment (pyrotinib group) and those receiving other neoadjuvant treatments (control group), were searched in EMBASE, Web of Science, Cochrane, PubMed, China National Knowledge Infrastructure, Wanfang, and SinoMed until December 2023. Six randomized controlled trials (RCTs) and 4 cohort studies were included. The pyrotinib group and control group contained 540 and 684 patients, respectively. Pathological complete response (pCR) was higher in the pyrotinib group than in the control group [relative risk (RR)=1.93; 95% confidence interval (CI) = 1.63-2.29; P < 0.001]. Similar results were discovered in subgroup analyses of RCTs (RR = 1.89; 95% CI = 1.49-2.40; P < 0.001) and cohort studies (RR = 1.98; 95% CI = 1.55-2.53; P < 0.001). The objective response rate (ORR) was also higher in the pyrotinib group than in the control group (RR = 1.14; 95% CI = 1.07-1.21; P < 0.001). Regarding adverse events, only the incidence of diarrhea was increased in the pyrotinib group versus the control group (RR = 1.97; 95% CI = 1.31-2.96; P = 0.001), while others were not different, including nausea and vomiting, leukopenia, thrombocytopenia, hand-foot syndrome, and alopecia (all P > 0.05). No publication bias existed, and sensitivity analysis suggested the satisfactory robustness of this meta-analysis. In conclusion, compared with other neoadjuvant treatments, pyrotinib-containing neoadjuvant treatment achieves a better treatment response with a good safety profile in HER2-positive breast cancer patients.

Case report: outcome of anlotinib treatment in breast cancer patient with brain metastases

Brain metastases (BM) represent a common and severe complication of breast cancer (BC), emerging in approximately 10%-16% of all BC patients. The prevalent approach for treating BC patients with BM encompasses a multimodal strategy, combining surgery, whole brain radiation therapy, and stereotactic radiosurgery. Yet, a concrete guideline for localized treatment strategies remains elusive, while systemic treatments like small-molecule-targeted therapy and immunotherapy are still in the clinical trial phase. This case study presents a significant clinical response to anlotinib treatment in a patient with estrogen receptor-negative, progesterone receptor-positive, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer, complicated by BM. After the standard first-line treatment including albumin-bound paclitaxel, trastuzumab and pertuzumab, and a second-line treatment involving pyrotinib, capecitabine, and radiotherapy did not produce the desired results, the patient was then administered anlotinib in combination with pyrotinib and letrozole as a third-line treatment, which led to a partial response (PR). The findings suggest that anti-angiogenic therapy, specifically anlotinib, could be regarded as a promising therapeutic option for BC patients with BM.

Case report: Pyrotinib and tegafur combined with radiotherapy achieved notable response in HER2-amplified rectal cancer with multiple metastases after multiline treatments

Metastatic colorectal cancer (mCRC) is characterized by significant phenotypic heterogeneity at the molecular level and presents a poor prognosis. Chemotherapy is commonly employed as the primary treatment option. Nevertheless, the advantages of chemotherapy are constrained, underscoring the critical necessity for novel treatment protocols aimed at enhancing patient outcomes. Human epidermal growth factor receptor 2 (HER2) has been recognized as a promising therapeutic target in mCRC. Pyrotinib, an innovative irreversible dual tyrosine kinase inhibitor targeting HER2, effectively inhibits cancer progression in various types of human cancers. Here, we present a case of a 39-year-old female with metastatic rectal cancer showing amplification of HER2. Despite resistance to multiple therapies, including trastuzumab and pertuzumab, the patient exhibited a remarkable therapeutic response to pyrotinib, tegafur combined with radiotherapy. This case provides evidence for the feasibility and potential efficacy of deploying pyrotinib in the salvage treatment of mCRC patients with HER2 amplification even though resistant to other anti-HER2 drugs.

Efficacy and safety of first-line regimens for advanced HER2-positive breast cancer: A Bayesian network meta-analysis

Background

The current standard of care for advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer is pertuzumab plus trastuzumab and docetaxel as first-line therapy. However, with the development of newer treatment regimens, there is a lack of evidence regarding which is the optimal treatment strategy. The aim of this network meta-analysis was to evaluate the efficacy and safety of first-line regimens for advanced HER2-positive breast cancer by indirect comparisons.

Methods

A systematic review and Bayesian network meta-analysis were conducted. The PubMed, EMBASE, and Cochrane Library databases were searched for relevant articles published through to December 2023. The hazard ratio (HR) and 95% credible interval (CrI) were used to compare progression-free survival (PFS) between treatments, and the odds ratio and 95% CrI were used to compare the objective response rate (ORR) and safety.

Results

Twenty randomized clinical trials that included 15 regimens and 7094 patients were analyzed. Compared with the traditional trastuzumab and docetaxel regimen, PFS was longer on the pyrotinib and trastuzumab plus docetaxel regimen (HR: 0.41, 95% CrI: 0.22-0.75) and the pertuzumab and trastuzumab plus docetaxel regimen (HR: 0.65, 95% CrI: 0.43-0.98). Consistent with the results for PFS, the ORR was better on the pyrotinib and trastuzumab plus docetaxel regimen and the pertuzumab and trastuzumab plus docetaxel regimen than on the traditional trastuzumab and docetaxel regimen. The surface under the cumulative ranking curve indicated that the pyrotinib and trastuzumab plus docetaxel regimen was most likely to rank first in achieving the best PFS and ORR. Comparable results were found for grade ≥3 AE rates of ≥10%.

Conclusions

Our results suggest that the pyrotinib and trastuzumab plus docetaxel regimen is most likely to be the optimal first-line therapy for patients with HER2-positive breast cancer.

Effectiveness and Safety of Pyrotinib-Based Therapy in the Treatment of HER2-Positive Breast Cancer Patients with Brain Metastases: A Multicenter Real-World Study

BACKGROUND

Approximately 30% to 50% of patients with human epidermal growth factor receptor 2-positive metastatic breast cancer develop brain metastasis (BMs). Pyrotinib has shown promising efficacy in these patients. However, real-world evidence supporting its use is scarce. Therefore, we evaluate the efficacy and safety of pyrotinib-based regimens in the real world.

MATERIALS AND METHODS

We enrolled patients with BMs from various healthcare facilities in China's Shandong region and used an updated breast-graded prognostic assessment (breast-GPA) to predict survival outcomes.

RESULTS

Efficacy and toxicity were assessed in 101 patients. Overall, the median progression-free survival (PFS) was 11.0 months (95% CI, 7.6-14.4 months). PFS was shorter in patients with a breast-GPA of 0 to 2.0 (P< .001). Previous treatment with pertuzumab plus trastuzumab (P = .039) and varying numbers of BMs (P = .028) had a significant positive correlation with PFS. Additionally, radiotherapy (P = .033) for BMs, especially pyrotinib concurrent with radiotherapy (P = .013), significantly prolonged the PFS. In patients with a breast-GPA of 0 to 2.0, a significant difference in PFS was observed depending on whether the brain was the first metastatic site (P< .001). Furthermore, a breast-GPA (0-2.0 vs. 2.5-4.0), and radiotherapy for BMs were found to be independent predictors of PFS. Overall, the objective response rate was 42.6%, while the disease control rate was 88.1%. Diarrhea emerged as the most common adverse event.

CONCLUSION

Pyrotinib-based therapy is effective and tolerable in human epidermal growth factor receptor 2-positive metastatic breast cancer with BMs. Patients who underwent radiotherapy for BMs, particularly those who received pyrotinib concurrently with radiotherapy, exhibited a more favorable prognosis.

Stereoselective Synthesis of Polysubstituted Dihydropyrroles via 1,5-Addition and N-1,4-Addition Cascade

An unprecedented 1,5-addition/N-1,4-addition cascade reaction is established via palladium hydride catalysis. A variety of polysubstituted dihydropyrrole skeletons are constructed in high yield and with exclusively >20 : 1 diastereoselectivity. An enantioselective protocol of this design is also developed to provide a novel access to enantioenriched dihydropyrroles.

Therapeutic strategies targeting the epidermal growth factor receptor signaling pathway in metastatic colorectal cancer

More than 1.9 million new colorectal cancer (CRC) cases and 935000 deaths were estimated to occur worldwide in 2020, representing about one in ten cancer cases and deaths. Overall, colorectal ranks third in incidence, but second in mortality. More than half of the patients are in advanced stages at diagnosis. Treatment options are complex because of the heterogeneity of the patient population, including different molecular subtypes. Treatments have included conventional fluorouracil-based chemotherapy, targeted therapy, immunotherapy, etc. In recent years, with the development of genetic testing technology, more and more targeted drugs have been applied to the treatment of CRC, which has further prolonged the survival of metastatic CRC patients.

Tackling breast cancer with gold nanoparticles: twinning synthesis and particle engineering with efficacy

The World Health Organization identifies breast cancer as the most prevalent cancer despite predominantly affecting women. Surgery, hormonal therapy, chemotherapy, and radiation therapy are the current treatment modalities. Site-directed nanotherapeutics, engineered with multidimensional functionality are now the frontrunners in breast cancer diagnosis and treatment. Gold nanoparticles with their unique colloidal, optical, quantum, magnetic, mechanical, and electrical properties have become the most valuable weapon in this arsenal. Their advantages include facile modulation of shape and size, a high degree of reproducibility and stability, biocompatibility, and ease of particle engineering to induce multifunctionality. Additionally, the surface plasmon oscillation and high atomic number of gold provide distinct advantages for tailor-made diagnosis, therapy or theranostic applications in breast cancer such as photothermal therapy, radiotherapy, molecular labeling, imaging, and sensing. Although pre-clinical and clinical data are promising for nano-dimensional gold, their clinical translation is hampered by toxicity signs in major organs like the liver, kidneys and spleen. This has instigated global scientific brainstorming to explore feasible particle synthesis and engineering techniques to simultaneously improve the efficacy and versatility and widen the safety window of gold nanoparticles. The present work marks the first study on gold nanoparticle design and maneuvering techniques, elucidating their impact on the pharmacodynamics character and providing a clear-cut scientific roadmap for their fast-track entry into clinical practice.

Safety and efficacy of pyrotinib for HER‑2‑positive breast cancer in the neoadjuvant setting: A systematic review and meta‑analysis

As a novel tyrosine kinase inhibitor (TKI), pyrotinib can irreversibly block dual pan-ErbB receptors and has been used in the treatment of advanced or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, there are limited data on the use of pyrotinib in early breast cancer. Therefore, the present meta-analysis was conducted to evaluate the safety and efficacy of pyrotinib in the neoadjuvant setting for patients with early-stage or locally advanced HER2-positive breast cancer. Online databases (Pubmed, Web of Science, Embase and Cochrane Library) were comprehensively searched for eligible prospective clinical trials on August 17, 2023. The primary endpoint was the treatment-related adverse events (TRAEs), and the secondary endpoint was pathological complete response (pCR) rate. In total, seven trials with a total enrolment of 407 patients were included. A total of seven studies evaluated pyrotinib in combination with trastuzumab and chemotherapy in the neoadjuvant setting. The median age ranged from 47-50 years. The most common TRAEs were diarrhea [98% of patients; 95% confidence interval (CI): 92-100%], followed by anemia (71%; 95% CI: 55-89%), vomiting (69%; 95% CI: 55-82%), and leucopenia (66%; 95% CI: 35-91%). No treatment-related deaths occurred. The pooled pCR rate was 57% (95% CI: 47-68%). It was concluded that pyrotinib-containing neoadjuvant therapy could be an effective treatment strategy in patients with early-stage or locally advanced HER2-positive breast cancer; however, the management of adverse events should be a key consideration. The management of adverse events should be paid great attention to, during pyrotinib therapy, although pyrotinib-contained neoadjuvant therapy could be an effective treatment for patients with early-stage or locally advanced HER2-positive breast cancer. Head-to-head randomized clinical trials are warranted to further confirm the benefits and risks associated with pyrotinib therapy in patients with breast cancer.

Efficacy and safety of pyrotinib combined with albumin-bound paclitaxel as first-line treatment for HER2-positive metastatic breast cancer in patients previously treated with adjuvant and/or neoadjuvant trastuzumab therapy: The stage 1 results of a single-arm, phase 2 prospective clinical trial

OBJECTIVE

It has been observed that the prognosis of patients with HER2-positive metastatic breast cancer has improved significantly with HER2-targeted agents. However, there is still a lack of evidence regarding first-line anti-HER2 treatment options for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, there are no reliable markers that can predict the efficacy of anti-HER2 treatment in these patients.

METHODS

Patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer were enrolled. Pyrotinib plus albumin-bound paclitaxel were used as first-line treatment. The primary endpoint was the objective response rate (ORR). The safety profile was also assessed. In order to explore predictive biomarkers using Olink technology, blood samples were collected dynamically.

RESULTS

From December 2019 to August 2023, the first stage of the study involved 27 eligible patients. It has not yet reached the median PFS despite the median follow-up being 17.8 months. Efficacy evaluation showed that the ORR was 92.6%, and the DCR was 100%. Adverse events of grade 3 or higher included diarrhoea (29.6%), leukopenia (11.1%), neutropenia (25.9%), oral mucositis (3.7%), and hand-foot syndrome (3.7%). Toll-like receptor 3 (TLR3) and Proto-oncogene tyrosine-protein kinase receptor (RET) were proteins with significant relevance to PFS in these patients.

CONCLUSIONS

This study demonstrates that pyrotinib plus albumin-bound paclitaxel as a first-line treatment regimen shows good efficacy and manageable safety for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, a significant association was identified between the expression levels of TLR3 and RET and the PFS in patients.

A comparative study of diaryl urea molecules with and without sulfonamide group on Carbonic anhydrase IX and XII inhibition and its consequence on breast cancer cells

To investigate the intrinsic relation between carbonic anhydrase inhibition and anticancer activity, we have prepared four sets of diaryl urea molecules and tested for the inhibition of hCA-IX and XII on two breast cancer cell lines. Among 21 compounds, compound J2 (with -SO2NH2 group) and J16 (without -SO2NH2 group) showed the best activity under normoxic and hypoxic conditions. The IC50 values of J16 for MDA-MB-231 and MCF-7 cells, under normoxic condition were 6.3 and 3.7 µM respectively, which are 1.9/3.3 and 15.8 times better than U-4-Nitro and SLC-0111 respectively. Whereas, under the hypoxic condition the corresponding values were 12.4 and 1.1 µM (MDA-MB-231 and MCF-7 cells respectively), which are equal/8 times better than U-4-Nitro. Whereas, J2 showed better IC50 value than U-4-Nitro (6.3 µM) under normoxic condition for both MDA-MB-231 and MCF-7 cells (1.9/2.7 times). Compound J2 inhibits the activity of hCA-IX and XII in nanomolar concentration [Ki values 4.09 and 9.10 nM respectively with selectivity ratio of 1.8 and 0.8 with hCA-II]. The crystal structure and modelling studies demonstrates that the inhibition of CAs arises due to the blocking of the CO2 coordination site of zinc in its catalytic domain. However, J16 was found to be unable to inhibit the activity of hCAs (Ki > 89000 nM). qPCR and western blot analysis showed a significant reduction (1.5 to 20 fold) of the transcription and expression of HIF1A, CA9 and CA12 genes in presence of J2 and J16. Both J2 and J16 found to reduce accumulation of HIF-1α protein by inhibiting the chaperone activity of hHSP70 with IC50 values of 19.4 and 15.3 µM respectively. Perturbation of the hCA-IX and XII activity by binding at active site or by reduced expression or by both leads to the decrease of intracellular pH, which resulted in concomitant increase of reactive oxygen species by 2.6/2.0 (MCF-7) and 2.9/1.8 (MDA-MB-231) fold for J2/J16. Increased cyclin D1 expression in presence of J2 and J16 was presumed to be indirectly responsible for the apoptosis of the cancer cells. Expression of the other apoptosis markers Bcl-2, Bim, caspase 9 and caspase 3 substantiated the apoptosis mechanism. However, decreased transcription/expression of HIF1A/HIF-1α and hCA-IX/XII also implies the inhibition of the extracellular signal-regulated kinase pathway by J2 and J16.

Pyrotinib Combined with Vinorelbine in Patients with Previously Treated HER2-Positive Metastatic Breast Cancer: A Multicenter, Single-Arm, Prospective Study

PURPOSE

This study aims to evaluate the efficacy and safety of a new combination treatment of vinorelbine and pyrotinib in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and provide higher level evidence for clinical practice.

MATERIALS AND METHODS

This was a prospective, single-arm, phase 2 trial conducted at three institutions in China. Patients with HER2-positive MBC, who had previously been treated with trastuzumab plus a taxane or trastuzumab plus pertuzumab combined with a chemotherapeutic agent, were enrolled between March 2020 and December 2021. All patients received pyrotinib 400 mg orally once daily plus vinorelbine 25 mg/m2 intravenously or 60-80 mg/m2 orally on day 1 and day 8 of 21-day cycle. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included the objective response rate (ORR), disease control rate (DCR), overall survival, and safety.

RESULTS

A total of 39 patients were enrolled. All patients had been pretreated with trastuzumab and 23.1% (n=9) of them had accepted trastuzumab plus pertuzumab. The median follow-up time was 16.3 months (95% confidence interval [CI], 5.3 to 27.2), and the median PFS was 6.4 months (95% CI, 4.0 to 8.8). The ORR was 43.6% (95% CI, 27.8% to 60.4%) and the DCR was 84.6% (95% CI, 69.5% to 94.1%). The median PFS of patients with versus without prior pertuzumab treatment was 4.6 and 8.3 months (p=0.017). The most common grade 3/4 adverse events were diarrhea (28.2%), neutrophil count decreased (15.4%), white blood cell count decreased (7.7%), vomiting (5.1%), and anemia (2.6%).

CONCLUSION

Pyrotinib plus vinorelbine showed promising efficacy and tolerable toxicity as second-line treatment in patients with HER2-positive MBC.

HER2-positive advanced biliary tract cancer responds to second-line pyrotinib therapy: a case report

Biliary tract cancers are solid tumors with poor prognosis and over 70% of patients present in advanced stages. The efficacy of second-line treatment for patients who progressed on GC chemotherapy is limited. Median OS of these patients is less than 1 year with palliative treatment. Despite the success of anti-HER2 therapy in HER2-positive breast cancer, the targeted therapy of HER2 mutations in BTCs is still being explored. This case report is the first report suggesting a 15-month PFS and partial response of pyrotinib in HER2-positive BTC. We report a 64-year-old female with HER2-positive biliary tract cancer. She was diagnosed with AJCC clinical stage IV (cT3N1M1) intrahepatic biliary tract cancer and got PD after 3 cycles of systemic chemotherapy of gemcitabine plus cisplatin. Due to the HER2-positive signature, pyrotinib (400 mg daily in 21-day cycles), an oral irreversible pan-ErbB TKI was prescribed in September 2021, with her informed consent. The tumor shrank significantly after this treatment and imaging assessments conducted on 24 September 2022 showed PR. Until the writing of the case draft, the patient had achieved 15 months of PFS. The present case suggests that Pyrotinib might be a potential effective treatment for HER2-positive advanced BTC.

Efficacy of Pyrotinib With/Without Trastuzumab in Treatment-Refractory, HER2-Positive Metastatic Colorectal Cancer: Result From a Prospective Observational Study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a promising therapeutic target in metastatic colorectal cancer (mCRC). This study was to evaluate the efficacy and safety of pyrotinib alone or pyrotinib with trastuzumab in patients with HER2-positive mCRC.

PATIENTS AND METHODS

In this prospective observational study, patients with HER2 positive, Ras Sarcoma Viral Oncogene Homolog (RAS) wild type mCRC who received at least one standard treatment of palliative chemotherapy were enrolled. Patients were treated with oral pyrotinib alone or pyrotinib with trastuzumab. The primary endpoint was progression free survival (PFS), and the secondary endpoints were overall survival (OS), confirmed objective response rate (ORR), and safety. This trial is registered with chitcr.org, number ChiCTR2100046381.

RESULTS

From February 15, 2021, to January 10, 2023, 32 patients were enrolled in this study. Twenty (62.5%) patients were treated with pyrotinib, while 12 (37.5%) received pyrotinib and trastuzumab. As of June 24, 2023, with a median follow-up of 11.0 months, the median PFS was 5.7 months (95%CI 4.5-10.2), while OS was not evaluable (NE), ORR and disease control rate (DCR were 34.4% and 87.5%. Patients' PFS in the pyrotinib plus trastuzumab subgroup and pyrotinib monotherapy group were 8.6 and 5.5 months, OS was not evaluable (NE) and 10.9 months, ORR was 50.0% and 25.0%, respectively. Most treatment-related adverse events (TRAEs) were grade 1-2, diarrhea was the most frequent TRAE (81.3%, 26/32). Grade 3 TRAEs occurred in 11 patients: 9 for diarrhea, 1 for nausea, and 1 for oral mucositis.

CONCLUSION

Pyrotinib with or without trastuzumab showed promising anti-tumor activity and acceptable toxicities in treatment-refractory, HER2-positive mCRC.

Profiling of ERBB receptors and downstream pathways reveals selectivity and hidden properties of ERBB4 antagonists

ERBB receptor tyrosine kinases are involved in development and diseases like cancer, cardiovascular, neurodevelopmental, and mental disorders. Although existing drugs target ERBB receptors, the next generation of drugs requires enhanced selectivity and understanding of physiological pathway responses to improve efficiency and reduce side effects. To address this, we developed a multilevel barcoded reporter profiling assay, termed 'ERBBprofiler', in living cells to monitor the activity of all ERBB targets and key physiological pathways simultaneously. This assay helps differentiate on-target therapeutic effects from off-target and off-pathway side effects of ERBB antagonists. To challenge the assay, eight established ERBB antagonists were profiled. Known effects were confirmed, and previously uncharacterized properties were discovered, such as pyrotinib's preference for ERBB4 over EGFR. Additionally, two lead compounds selectively targeting ERBB4 were profiled, showing promise for clinical trials. Taken together, this multiparametric profiling approach can guide early-stage drug development and lead to improved future therapeutic interventions.

Efficacy and safety of first-line therapy in patients with HER2-positive advanced breast cancer: a network meta-analysis of randomized controlled trials

PURPOSE

The numerous first-line treatment regimens for human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC) necessitate a comprehensive evaluation to inform clinical decision-making. We conducted a Bayesian network meta-analysis (NMA) to compare the efficacy and safety of different interventions.

METHODS

We systematically searched for relevant randomized controlled trials (RCTs) in Pubmed, Embase, Cochrane Library and online abstracts from inception to June 1, 2023. NMA was performed to calculate and analyze progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and adverse events of grade 3 or higher (≥ 3 AEs).

RESULTS

Out of the 10,313 manuscripts retrieved, we included 28 RCTs involving 11,680 patients. Regarding PFS and ORR, the combination of trastuzumab with tyrosine kinase inhibitors (TKIs) was more favorable than dual-targeted therapy. If only using trastuzumab, combination chemotherapy is superior to monochemotherapy in terms of PFS. It is important to note that the addition of anthracycline did not result in improved PFS. For patients with hormone receptor-positive HER2-positive diseases, dual-targeted combined with endocrine therapy showed better benefit in terms of PFS compared to dual-targeted alone, but it did not reach statistical significance. The comprehensive analysis of PFS and ≥ 3 AEs indicates that monochemotherapy combined with dual-targeted therapy still has the optimal balance between efficacy and safety.

CONCLUSION

Monochemotherapy (Docetaxel) plus dual-target (Trastuzumab and Pertuzumab) therapy remains the optimal choice among all first-line treatment options for ABC. The combination of trastuzumab with TKIs (Pyrotinib) demonstrated a significant improvement in PFS and ORR, but further data are warranted to confirm the survival benefit.

Management and Mechanisms of Diarrhea Induced by Tyrosine Kinase Inhibitors in Human Epidermal Growth Factor Receptor-2-Positive Breast Cancer

Breast cancer has the highest incidence among female malignancies, significantly impacting women's health. Recently, numerous HER2-targeted therapies have achieved excellent clinical outcomes. Currently, anti-HER2 drugs are divided into three main categories: monoclonal antibodies, small-molecule tyrosine kinase inhibitors, and antibody-coupled drugs (ADCs). The main toxic side effects of small molecule TKI-based therapy are diarrhea, hand-foot syndrome, rash, nausea, and vomiting. Diarrhea is a potential predictor of tumor response, affecting up to 95% of cancer patients treated with TKIs. Severe gastrointestinal toxicity can result in the need for dose reductions and treatment interruptions. This not only compromises the efficacy of TKIs but also deteriorates human nutrition and quality of life. The majority of individuals develop diarrhea within 7 days of starting treatment, with approximately 30% developing grade 3 or higher diarrhea within 2-3 days of starting treatment. The severity of diarrhea typically correlates with the dosage of most TKIs. Current prevention and management strategies are primarily empirical, focusing on symptom alleviation rather than addressing the toxicological mechanisms underlying TKI-induced diarrhea. Consequently, anti-diarrheal drugs are often less effective in managing this condition in cancer patients receiving TKIs. Moreover, our understanding of the toxicological mechanisms responsible for such diarrhea remains limited, underscoring the urgent need to identify these mechanisms in order to develop effective anti-diarrheal medications tailored to this specific context. This review aims to elucidate management approaches and mechanisms for diarrhea induced by TKIs during HER2-positive breast cance.

The Efficacy and Safety of Inetetamab and Pyrotinib in Combination with Vinorelbine for Second-line Therapy and Beyond in HER2-positive Metastatic Breast Cancer: A Single-institution Clinical Experience

BACKGROUND AND OBJECTIVES

This study aimed to observe the efficacy and safety of inetetamab and pyrotinib in combination with vinorelbine in second-line therapy and beyond in HER2-positive metastatic breast cancer (MBC).

METHODS

Patients with HER2-positive MBC admitted to our hospital from January 2016 to December 2021 were selected. For patients who could not receive antibody‒drug conjugates (ADCs) during second-line (2nd-line) or third-line and beyond (≥ 3rd-line) anti-HER2 therapy, inetetamab + pyrotinib + vinorelbine was used for treatment until unacceptable adverse events occurred or the disease progressed, as evaluated by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 every 2 cycles. The progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR), and adverse reactions were recorded. Multivariate Cox regression analysis was performed to explore the prognostic factors influencing the curative effect.

RESULTS

Overall, 52 patients were included; 13 patients received 2nd-line treatment, and 39 patients received ≥ 3rd-line treatment. The median PFS (mPFS) for all patients treated with inetetamab + pyrotinib + vinorelbine was 7 months. The mPFS of the 2nd-line subgroup was significantly better than that of the ≥ 3rd-line subgroup (17 vs. 5 months, P = 0.001). The mPFS of the subgroups that received trastuzumab (H) or trastuzumab and pertuzumab (HP) only was significantly better than that of the H or HP and tyrosine kinase inhibitor (TKI) subgroups (8 vs. 5 months, P = 0.030). The mPFS of the HER2 resistance subgroup was better than that of the HER2 refractoriness subgroup (14 vs. 7 months, P = 0.025). Cox regression analysis showed that the treatment line (2nd-line more so than ≥ 3rd-line) was an independent prognostic factor for PFS. In addition, the ORR and CBR of 2nd-line patients were significantly higher than those of ≥ 3rd-line patients (69.2% vs. 30.8% and 92.3% vs. 64.1%, respectively). The most common hematological toxicities were leukopenia and neutropenia, and the most common nonhematological toxicity was diarrhea.

CONCLUSION

Inetetamab and pyrotinib in combination with vinorelbine have good efficacy in ≥ 2nd-line treatment of HER2-positive MBC with controllable toxicity, and the combination is a new treatment option, especially for patients who cannot use ADCs in 2nd-line treatment.

Understanding the mechanistic pathways and clinical aspects associated with protein and gene based biomarkers in breast cancer

Cancer is one of the most widespread and severe diseases with a huge mortality rate. In recent years, the second-leading mortality rate of any cancer globally has been breast cancer, which is one of the most common and deadly cancers found in women. Detecting breast cancer in its initial stages simplifies treatment, decreases death risk, and recovers survival rates for patients. The death rate for breast cancer has risen to 0.024 % in some regions. Sensitive and accurate technologies are required for the preclinical detection of BC at an initial stage. Biomarkers play a very crucial role in the early identification as well as diagnosis of women with breast cancer. Currently, a wide variety of cancer biomarkers have been discovered for the diagnosis of cancer. For the identification of these biomarkers from serum or other body fluids at physiological amounts, many detection methods have been developed. In the case of breast cancer, biomarkers are especially helpful in discovering those who are more likely to develop the disease, determining prognosis at the time of initial diagnosis and choosing the best systemic therapy. In this study we have compiled various clinical aspects and signaling pathways associated with protein-based biomarkers and gene-based biomarkers.

Novel HER-2 Targeted Therapies in Breast Cancer

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

Neoadjuvant pyrotinib plus trastuzumab and chemotherapy for HER2-positive breast cancer: a prospective cohort study

BACKGROUND

This prospective study aims to investigate the efficacy and safety of pyrotinib (P) combined with 4 cycles of epirubicin and cyclophosphamide followed by 4 cycles of taxane and trastuzumab (P + EC-TH) regimen as neoadjuvant therapy for human epidermal growth factor receptor 2 (HER2) positive breast cancer and to investigate the predictive value of p53, p63, and epidermal growth factor receptor (EGFR) status for neoadjuvant efficacy.

METHODS

A total of 138 HER2-positive breast cancer patients who received neoadjuvant therapy and underwent surgery were included. Case group: 55 patients received P + EC-TH regimen.

CONTROL GROUP

83 patients received EC-TH regimen. The chi-square test, Fisher's exact test, and logistic regression analysis were applied. The primary endpoint was total pathologic complete response (tpCR), and the secondary endpoints were breast pathologic complete response (bpCR), overall response rate (ORR), and adverse events (AEs).

RESULTS

In the case group, the tpCR rate was 63.64% (35/55), the bpCR rate was 69.09% (38/55), and the ORR was 100.00% (55/55). In the control group, the tpCR rate was 39.76% (33/83), the bpCR rate was 44.58% (37/83), and the ORR was 95.18% (79/83). The case group had significantly higher tpCR and bpCR rates than those of the control group (P < 0.05), but there was no significant difference in ORR (P > 0.05). The tpCR was associated with the status of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), and the patients with any negative ER, PR, AR, or combined, were more likely to achieve tpCR than those with positive results (P < 0.05). The p53-positive patients were more likely to achieve tpCR and bpCR than p53-negative patients (P < 0.05). The incidence of hypokalemia and diarrhea in the case group was higher than that in the control group (P < 0.05). The AEs developed were all manageable, and no treatment-related death occurred.

CONCLUSION

The efficacy and safety of the P + EC-TH regimen were verified by this study. The HER2-positive breast cancer patients treated with the EC-TH neoadjuvant regimen were more likely to achieve tpCR or bpCR if pyrotinib was administered simultaneously.

Pyrotinib and chrysin synergistically potentiate autophagy in HER2-positive breast cancer

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has been the most challenging subtype of BC, consisting of 20% of BC with an apparent correlation with poor prognosis. Despite that pyrotinib, a new HER2 inhibitor, has led to dramatic improvements in prognosis, the efficacy of pyrotinib monotherapy remains largely restricted due to its acquired resistance. Therefore, identifying a new potential antitumor drug in combination with pyrotinib to amplify therapeutic efficacy is a pressing necessity. Here, we reported a novel combination of pyrotinib with chrysin and explored its antitumor efficacy and the underlying mechanism in HER2-positive BC. We determined that pyrotinib combined with chrysin yielded a potent synergistic effect to induce more evident cell cycle arrest, inhibit the proliferation of BT-474 and SK-BR-3 BC cells, and repress in vivo tumor growth in xenograft mice models. This may be attributed to enhanced autophagy induced by endoplasmic reticulum stress. Furthermore, the combined treatment of pyrotinib and chrysin induced ubiquitination and glucose-6-phosphate dehydrogenase (G6PD) degradation by upregulating zinc finger and BTB/POZ domain-containing family protein 16 (ZBTB16) in tumorigenesis of BC. Mechanistically, we identified that miR-16-5p was a potential upstream regulator of ZBTB16, and it showed a significant inverse correlation with ZBTB16. Inhibition of miR-16-5p overexpression by restoring ZBTB16 significantly potentiated the overall antitumor efficacy of pyrotinib combined with chrysin against HER2-positive BC. Together, these findings demonstrate that the combined treatment of pyrotinib and chrysin enhances autophagy in HER2-positive BC through an unrecognized miR-16-5p/ZBTB16/G6PD axis.

Pyrotinib plus docetaxel as first-line treatment for HER2-positive metastatic breast cancer: the PANDORA phase II trial

The role of pyrotinib in the treatment of HER2-positive metastatic breast cancer (MBC) has been well-established. This multicenter, single-arm phase II trial (NCT03876587) aimed to assess the benefit of pyrotinib plus docetaxel as a first-line treatment for HER2-positive MBC. Women with HER2-positive MBC who had not undergone HER2 blockade or chemotherapy for metastatic disease were enrolled in the study and received daily oral pyrotinib 400 mg plus intravenous docetaxel 75 mg/m2 every 3 weeks. The primary endpoint was the objective response rate (ORR), secondary endpoints included progression-free survival (PFS), duration of response (DoR), clinical benefit rate (CBR), overall survival (OS) and safety. From June 2019 to June 2021, 79 patients were enrolled. The confirmed ORR was 79.7% (95% confidence interval [CI], 70.8-88.6), and the CBR was 87.3% (95%CI, 80.0-94.6) in the intention-to-treat population. The pre-specified primary endpoint was met. The median DoR was 15.9 months (interquartile range, 8.3-19.5); the median PFS was 16.0 months (95% CI, 11.2-20.8), and the median OS was not reached. The most common grade ≥3 treatment-related adverse events observed were leukopenia (29.1%), neutropenia (27.8%), and diarrhea (21.5%). This study demonstrates that pyrotinib plus docetaxel show an acceptable safety profile and promising antitumor activity as a first-line treatment option for patients with HER2-positive MBC.

Comparing pyrotinib with trastuzumab and pertuzumab with trastuzumab for HER2-positive metastatic breast cancer: a retrospective, multicenter analysis

Objective

Pyrotinib and pertuzumab are effective treatment options for HER2-positive metastatic breast cancer (HER2+ MBC). Our study was to directly compare the efficacy and safety of pyrotinib plus trastuzumab (PyroH) and pertuzumab plus trastuzumab (HP) in patients with HER2+ MBC.

Methods

We conducted a retrospective examination of HER2+ MBC patients who received PyroH plus chemotherapy or HP plus chemotherapy between 2017 and 2022 at five institutions in China. Our primary endpoint was progression-free survival (PFS).

Results

This study involved 333 patients, among which 161 received PyroH and 172 received HP. The utilization of PyroH as a first-line therapy for MBC was more prevalent among older patients, those with a shorter duration of disease-free interval, or those who had previously been treated with trastuzumab. Although in the first-line advanced treatment HP cohort showed numerically longer PFS (median PFS: 14.46 vs. 22.90 months, p=0.057), in the second-line or later treatments, there was no significant difference in PFS between the PyroH and HP groups (median PFS: 8.67 vs. 7.92 months, p=0.286). Despite HP showing a longer PFS in the overall cohort (median PFS: 9.30 vs. 13.01 months, p=0.005), it did not serve as an independent predictor of PFS in the multivariate analysis (HR 1.134, 95% CI 0.710-1.811, p=0.598). Without taxane, PyroH demonstrated a longer PFS than HP (median PFS: 10.12 vs. 8.15 months, p=0.017). PyroH group displayed a numerically longer median PFS in patients with brain metastases compared to the HP group, though not statistically significant (median PFS: 9.03 vs. 8.15 months, p=0.976). PyroH had higher incidence of grade 3/4 diarrhea (34.3% vs. 3.0%) but similar overall adverse events.

Conclusion

In conclusion, PyroH is comparable in second-line or later treatment and during brain metastasis, even having superior efficacy without taxane in real-world setting. Toxicities were tolerable in both groups. (ClinicalTrials.gov: NCT05572645).

Efficacy and safety of a pyrotinib-based regimen in non-small cell lung cancer patients harboring HER2 alterations: A real-world retrospective study

BACKGROUND

Pyrotinib, a novel irreversible pan-HER tyrosine kinase inhibitor, has been approved for the treatment of HER2-positive metastatic breast cancer in China. The aim of this study was to evaluate the efficacy and safety of pyrotinib in advanced nonsmall cell lung cancer (NSCLC) patients with HER2 alterations in real-world practice.

MATERIALS AND METHODS

A retrospective analysis of advanced NSCLC with HER2 mutations or amplifications who received pyrotinib-based treatment at the Qilu Hospital in Shandong University was performed. The primary end points were objective response rate and safety. The secondary end points were progression-free survival, disease control rate, and overall survival.

RESULTS

Twenty three eligible patients from a single center were enrolled between June 2019 and March 2023; among them, 21 had HER2 mutation and two harbored HER2 amplification. Evaluation of the efficacy in 21 patients revealed an objective response rate of 28.6% (6/21; 95% confidence interval [CI]: 7.5%-49.6%) and disease control rate of 85.7% (18/21). The median progression-free survival and overall survival were 7.7 months (95% CI: 6.07-9.33) and 20.8 months (95% CI: 8.42-33.18), respectively. The most common adverse events (AEs) included diarrhea (n = 14, 60.9%), nausea (n = 5, 21.7%), and liver dysfunction (n = 5, 21.7%). Seven patients (7/23, 30.4%) had grade 3-4 AE; no grade 5 AE was observed. Furthermore, one patient (1/23, 4.3%) experienced dose withdrawal and two (2/23, 8.7%) presented with dose reduction symptoms.

CONCLUSION

Pyrotinib-based therapy showed promising antitumor activity and acceptable safety in advanced NSCLC patients with HER2 alterations.

Efficacy and safety of trastuzumab with or without a tyrosine kinase inhibitor for HER2-positive breast cancer: A systematic review and meta-analysis

BACKGROUND

This study aimed to explore the efficacy and safety of trastuzumab plus tyrosine kinase inhibitors (TKIs) compared with those of trastuzumab monotherapy in patients with human epidermal growth factor receptor (HER2)-positive breast cancer.

METHODS

The PubMed, Embase, Cochrane, and Web of Science databases were systematically searched for relevant articles from inception until September 2022. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Subgroup analyses were performed based on disease status, TKI type, and hormone receptor status.

RESULTS

Sixteen studies were included in the current analysis. Trastuzumab plus TKI significantly improved OS and PFS compared to trastuzumab monotherapy. In the neoadjuvant setting, trastuzumab plus TKI significantly increased the pathologic complete response (pCR) rate compared to trastuzumab monotherapy. Moreover, a higher objective response rate (ORR) was observed with trastuzumab plus TKI. Patients who received the combination therapy had a higher incidence of discontinuation, all-grade diarrhea, and grade ≥ 3 diarrhea.

CONCLUSIONS

Trastuzumab plus TKI was better than trastuzumab monotherapy for treating different stages of HER2-positive breast cancer. The safety of trastuzumab plus TKI anti-HER2 therapy was controllable. The different efficacies of TKIs combined with trastuzumab may be related to the mechanism of action of the different TKIs, needing further investigations.

Pyrotinib versus placebo in combination with trastuzumab and docetaxel as first line treatment in patients with HER2 positive metastatic breast cancer (PHILA): randomised, double blind, multicentre, phase 3 trial

OBJECTIVE

To assess the efficacy and safety of pyrotinib (an irreversible pan-HER (human epidermal growth factor receptor) inhibitor), trastuzumab, and docetaxel compared with placebo, trastuzumab, and docetaxel for untreated HER2 positive metastatic breast cancer.

DESIGN

Randomised, double blind, placebo controlled, multicentre, phase 3 trial.

SETTING

40 centres in China between 6 May 2019 and 17 January 2022.

PARTICIPANTS

590 female patients (median age 52 (interquartile range 46-58) years) with untreated HER2 positive metastatic breast cancer.

INTERVENTIONS

Eligible patients were randomised 1:1 to receive either oral pyrotinib (400 mg once daily) or placebo, both combined with intravenous trastuzumab (8 mg/kg in cycle 1 and 6 mg/kg in subsequent cycles) and docetaxel (75 mg/m2) on day 1 of each 21 day cycle. Randomisation was stratified by treatment history of trastuzumab in the (neo)adjuvant setting and hormone receptor status. Patients, investigators, and the sponsor's study team were masked to treatment assignment.

MAIN OUTCOME MEASURES

The primary endpoint was progression-free survival as assessed by the investigator.

RESULTS

Of the 590 randomised patients, 297 received pyrotinib, trastuzumab, and docetaxel treatment (pyrotinib group), and 293 received placebo, trastuzumab, and docetaxel treatment (placebo group). At data cut-off on 25 May 2022, the median follow-up was 15.5 months. The median progression-free survival according to the investigator was significantly longer in the pyrotinib group than in the placebo group (24.3 (95% confidence interval 19.1 to 33.0) months versus 10.4 (9.3 to 12.3) months; hazard ratio 0.41 (95% confidence interval 0.32 to 0.53); one sided P<0.001). Treatment related adverse events of grade 3 or higher were reported in 267 (90%) of the 297 patients in the pyrotinib group and 224 (76%) of the 293 patients in the placebo group. No treatment related deaths occurred in the pyrotinib group, and one (<1%; diabetic hyperosmolar coma) treatment related death occurred in the placebo group. Survival and toxicities are still under assessment with longer follow-up.

CONCLUSIONS

Pyrotinib, trastuzumab, and docetaxel showed superiority by significantly improving progression-free survival compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2 positive metastatic breast cancer. The toxicity was manageable. The findings support this dual anti-HER2 regimen as an alternative first line treatment option in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03863223.

Dalpiciclib and pyrotinib in women with HER2-positive advanced breast cancer: a single-arm phase II trial

CDK4/6 inhibitors have shown a synergistic effect with anti-HER2 therapy in hormone receptor (HR)-positive and HER2-positive breast cancer (BC). In this phase 2 study (NCT04293276), we aim to evaluate a dual-oral regimen of CDK4/6 inhibitor dalpiciclib combined with HER2 tyrosine kinase inhibitor pyrotinib as front-line treatment in women with HER2-positive advanced BC (n = 41) including those with HR-negative disease. The primary endpoint is the objective response rate, and secondary endpoints include progression-free survival (PFS), overall survival (OS), and safety. With a median follow-up of 25.9 months, 70% (28/40) of assessable patients have a confirmed objective response, meeting the primary endpoint. The median PFS is 11.0 months (95% CI = 7.3-19.3), and OS data are not mature. The most common grade 3 or 4 treatment-related adverse events (AEs) are decreased white blood cell count (68.3%), decreased neutrophil count (65.9%), and diarrhea (22.0%). Most AEs are manageable, and no treatment-related deaths occur. These findings suggest that this combination may have promising activity and manageable toxicity. Further investigation is needed.

Pyrotinib-based therapeutic approaches for HER2-positive breast cancer: the time is now

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) is a highly aggressive subtype associated with poor prognosis. The advent of HER2-targeted drugs, including monoclonal antibodies, tyrosine-kinase inhibitors (TKIs) and antibody-drug conjugates, has yielded improved prognosis for patients. Compared with widely used monoclonal antibodies, small-molecule TKIs have unique advantages including oral administration and favorable penetration of blood-brain barrier for brain metastatic BC, and reduced cardiotoxicity. Pyrotinib is an irreversible TKI of the pan-ErbB receptor, and has recently been shown to be clinically effective for the treatment of HER2-positive BC in metastatic and neoadjuvant settings. This review highlights the development on the application of pyrotinib-based therapeutic approaches in the clinical settings of HER2-positive BC.

Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials

Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.

P110α inhibitor alpelisib exhibits a synergistic effect with pyrotinib and reverses pyrotinib resistant in HER2+ breast cancer

Human epidermal growth factor receptor 2 (HER2) plays a critical role in breast cancer progression in patients with HER2 overexpression, thereby driving the development of targeted drugs and advancing therapy strategies targeting this gene. Pyrotinib is a novel irreversible pan-ErbB kinase inhibitor, primarily suppresses the downstream MAPK and PI3K/AKT pathways. Alpelisib, a selective PI3K p110α inhibitor, has been approved for clinical application in HR+, HER2-, PIK3CA mutated breast cancers and is also being developed for use in other breast cancer subtypes. In this study, we hypothesised that combining pyrotinib with alpelisib would yield superior results compared to single-drug treatment. Our data demonstrated that the combination of alpelisib and pyrotinib exhibited a synergistic effect in HER2+ breast cancer both in vitro and in vivo. This combination led to decreased cell proliferation and migration, G0-G1 cell cycle arrest, and increased apoptosis rates. Additionally, the deactivation of ErbB receptors and sustained activation of PI3K/AKT pathway by upstream compensatory pathways induced acquired pyrotinib resistant cells resistant to pyrotinib treatment, thus alpelisib combined with pyrotinib showed a tremendous synergistic effect and reverse pyrotinib resistance in acquired pyrotinib resistant cells by suppressing the activated PI3K/AKT pathway. Our results revealed a combination of pyrotinib and alpelisib as an effective therapeutic strategy in treating HER2+ breast cancer, whether sensitive or resistant to pyrotinib treatment.

Pyrotinib in combination with letrozole for hormone receptor-positive, human epidermal growth factor receptor 2-positive metastatic breast cancer (PLEHERM): a multicenter, single-arm, phase II trial

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) targeted therapy combined with endocrine therapy has been recommended as an alternative treatment strategy for patients with hormone receptor (HR)-positive, HER2-positive metastatic breast cancer (MBC). This study aimed to evaluate the role of pyrotinib, an oral pan-HER irreversible tyrosine kinase inhibitor, in combination with letrozole for patients with HR-positive, HER2-positive MBC.

METHODS

In this multi-center, phase II trial, HR-positive and HER2-positive MBC patients who were not previously treated for metastasis disease were enrolled. Patients received daily oral pyrotinib 400 mg and letrozole 2.5 mg until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was the clinical benefit rate (CBR) assessed by an investigator according to the Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

From November 2019 to December 2021, 53 patients were enrolled and received pyrotinib plus letrozole. As of August 2022, the median follow-up duration was 11.6 months (95% confidence interval [CI], 8.7-14.0 months). The CBR was 71.7% (95% CI, 57.7-83.2%), and the objective response rate was 64.2% (95% CI, 49.8-76.9%). The median progression-free survival was 13.7 months (95% CI, 10.7-18.7 months). The most common treatment-related adverse event of grade 3 or higher was diarrhea (18.9%). No treatment-related deaths were reported, and one patient experienced treatment discontinuation due to adverse event.

CONCLUSIONS

Our preliminary results suggested that pyrotinib plus letrozole is feasible for the first-line treatment of patients with HR-positive and HER2-positive MBC, with manageable toxicities.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04407988.

Real-world data of pyrotinib-based therapy for patients with brain metastases of HER2-positive advanced breast cancer: a single-center retrospective analysis and molecular portraits

Introduction

Pyrotinib is a novel irreversible pan-HER tyrosine kinase inhibitor (TKI). However, real-world data of pyrotinib-containing therapy in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and developing brain metastases (BMs) are limited, and the genomic profile of this subpopulation is almost undefined.

Methods and materials

Patients with BM of HER2-positive MBC (n = 35) treated with pyrotinib-containing therapy were enrolled in this analysis. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and toxicity profiles were evaluated. Hazard ratios (HRs) and 95% confidence intervals (CIs) for disease progression were estimated using the Cox proportional hazards models. Targeted next-generation sequencing of 618 cancer-relevant genes was performed on plasma and primary breast tumors from patients with BM and without BM.

Results

The median PFS time was 8.00 (95% CI, 5.98-10.017) months, and the median OS time was 23 (95% CI, 10.412-35.588) months. The ORR was 45.7%, and the DCR was 74.3%. In the Cox multivariate analysis, prior exposure to brain radiotherapy (HR = 3.268), received pyrotinib as third- or higher-line treatment (HR = 4.949), subtentorial brain metastasis (HR = 6.222), and both supratentorial and subtentorial brain metastases (HR = 5.863) were independently associated with increased risk of progression. The frequent grade 3-4 adverse event was increased direct bilirubin (14.3%), and two patients suffered from grade 3-4 diarrhea. In the exploratory genomic analysis, altered frequencies of FGFR3, CD276, CDC73, and EPHX1 were higher in the BM group. The consistency of mutated profiles of plasma and primary lesion in the BM group was significantly lower (30.4% vs. 65.5%; p = 0.0038).

Conclusions

Pyrotinib-containing therapy shows favorable effectiveness and tolerable safety in patients with BM of HER2-positive MBC, particularly in a population that is brain radiotherapy-naïve, received pyrotinib as first- or second-line treatment, and developed supratentorial brain metastasis. In the exploratory genomic analysis, patients with BM showed distinct genomic features from patients without BM.

Cross-species comparison in nonclinical pharmacokinetics of lenvatinib by a simple HPLC with ultraviolet detection

Lenvatinib (Lenvima) is a tyrosine kinase inhibitor on the market and has been used for the treatment of various types of cancer. It is important to understand differences in pharmacokinetics (PK) between nonclinical animals and humans, and thus, we evaluated PK of lenvatinib in mice, rats, dogs, and monkeys. A simple assay for lenvatinib was developed by high performance liquid chromatography with ultraviolet detection and validated in accordance with the bioanalytical guidelines. Lenvatinib was quantifiable at 5-100,000 ng/mL using 50 μL of plasma. Accuracy and precision in the intra- and inter-batch reproducibility were within the acceptance criteria, indicating a robust assay. Lenvatinib was intravenously or orally administered to mice, rats, dogs, and monkeys to fully characterize the cross-species PK. Total clearance and volume of distribution were relatively low and bioavailability of lenvatinib was approximately 64-78% in all the species tested. PK of lenvatinib in mice and rats after oral dose was almost linear at the doses ranging from 3 to 30 mg/kg. An empirical allometric scaling successfully predicted oral systemic exposure of lenvatinib in humans. Collectively, PK profiles of lenvatinib in nonclinical animals were well characterized and were useful for PK prediction in humans.

Pathologic Complete Response Achieved in Early-Stage HER2-Positive Breast Cancer After Neoadjuvant Therapy With Trastuzumab and Chemotherapy vs. Trastuzumab, Chemotherapy, and Pertuzumab: A Systematic Review and Meta-Analysis of Clinical Trials

Patients diagnosed with human epidermal growth factor receptor 2 (HER2)-positive breast cancer require treatment upfront because of the aggressive nature of this type of cancer. Patients with early-stage HER2-positive breast cancer are usually treated with neoadjuvant therapy. This neoadjuvant therapy comprises targeted therapy and chemotherapy. Targeted therapy is given with trastuzumab. Pertuzumab is either administered or not with trastuzumab as a targeted therapy. This systematic review and meta-analysis aim to find out and compare the benefit achieved in terms of pathologic complete response (pCR) by adding pertuzumab to the neoadjuvant treatment regimen for early-stage HER2-positive breast cancer patients. Various databases were searched to find out relevant clinical trials. After going through PubMed, Embase, and Cochrane, three clinical trials were shortlisted for this systematic review and meta-analysis. These three clinical trials were double-armed. Pertuzumab was present in one arm while being absent in one arm to assess the benefit of adding pertuzumab in terms of pCR achieved. Data were analyzed using RevMan Web (Cochrane, London, UK). The odds ratio and 95% confidence interval were calculated for the outcome. The Mantel-Haenszel method and random effect model were used for analysis. The risk of bias in studies was evaluated using the Cochrane risk of bias tool for randomized controlled trials (ROB2). The summary statistics showed that the incidence of pCR was more in the experimental group (having pertuzumab) as compared to the control group (without pertuzumab) with an odds ratio of 2.10 (95% CI: 1.56-2.83) with I2 = 0%. In three double-arm trials, there were 840 participants, 445 in the experimental group and 395 in the control group. A total of 203 (45%) patients out of 445 in the experimental group achieved pCR, whereas 127 (32%) patients out of 395 in the control group achieved pCR. Through the results of this study, it can be concluded that the rate of pCR achieved was higher in that arm in which pertuzumab was present compared to the study arm in which only trastuzumab was given as targeted therapy. Thus, it can be suggested that pertuzumab be added to the neoadjuvant regimen for early-stage HER2-positive breast cancer patients. This would result in achieving a better pCR. And by improving pCR rates, the survival outcomes of patients can be significantly improved.

Recent Advances with Precision Medicine Treatment for Breast Cancer including Triple-Negative Sub-Type

Breast cancer is a heterogeneous disease with different molecular subtypes. Breast cancer is the second leading cause of mortality in woman due to rapid metastasis and disease recurrence. Precision medicine remains an essential source to lower the off-target toxicities of chemotherapeutic agents and maximize the patient benefits. This is a crucial approach for a more effective treatment and prevention of disease. Precision-medicine methods are based on the selection of suitable biomarkers to envision the effectiveness of targeted therapy in a specific group of patients. Several druggable mutations have been identified in breast cancer patients. Current improvements in omics technologies have focused on more precise strategies for precision therapy. The development of next-generation sequencing technologies has raised hopes for precision-medicine treatment strategies in breast cancer (BC) and triple-negative breast cancer (TNBC). Targeted therapies utilizing immune checkpoint inhibitors (ICIs), epidermal growth factor receptor inhibitor (EGFRi), poly(ADP-ribose) polymerase inhibitor (PARPi), antibody-drug conjugates (ADCs), oncolytic viruses (OVs), glucose transporter-1 inhibitor (GLUT1i), and targeting signaling pathways are potential treatment approaches for BC and TNBC. This review emphasizes the recent progress made with the precision-medicine therapy of metastatic breast cancer and TNBC.

Emerging Targeted Therapies for HER2-Positive Breast Cancer

Breast cancer is the most common cancer in women and the leading cause of death. HER2 overexpression is found in approximately 20% of breast cancers and is associated with a poor prognosis and a shorter overall survival. Tratuzumab, a monoclonal antibody directed against the HER2 receptor, is the standard of care treatment. However, a third of the patients do not respond to therapy. Given the high rate of resistance, other HER2-targeted strategies have been developed, including monoclonal antibodies such as pertuzumab and margetuximab, trastuzumab-based antibody drug conjugates such as trastuzumab-emtansine (T-DM1) and trastuzumab-deruxtecan (T-DXd), and tyrosine kinase inhibitors like lapatinib and tucatinib, among others. Moreover, T-DXd has proven to be of use in the HER2-low subtype, which suggests that other HER2-targeted therapies could be successful in this recently defined new breast cancer subclassification. When patients progress to multiple strategies, there are several HER2-targeted therapies available; however, treatment options are limited, and the potential combination with other drugs, immune checkpoint inhibitors, CAR-T cells, CAR-NK, CAR-M, and vaccines is an interesting and appealing field that is still in development. In this review, we will discuss the highlights and pitfalls of the different HER2-targeted therapies and potential combinations to overcome metastatic disease and resistance to therapy.

Opposite and dynamic regulation of the interferon response in metastatic and non-metastatic breast cancer

BACKGROUND

To our current understanding, solid tumors depend on suppressed local immune reactions, often elicited by the interaction between tumor cells and tumor microenvironment (TME) components. Despite an improved understanding of anti-cancer immune responses in the TME, it is still unclear how immuno-suppressive TME are formed and how some cancer cells survive and metastasize.

METHODS

To identify the major adaptations that cancer cells undergo during tumor development and progression, we compared the transcriptome and proteome from metastatic 66cl4 and non-metastatic 67NR cell lines in culture versus their corresponding mouse mammary primary tumors. Using confocal microscopy, RT-qPCR, flow cytometry and western blotting, we studied the signaling pathway and the mechanisms involved. In addition, we used public gene expression data from human breast cancer biopsies to evaluate the correlation between gene expression and clinical outcomes in patients.

RESULTS

We found that type I interferon (IFN-I) response was a key differentially regulated pathway between metastatic and non-metastatic cell lines and tumors. The IFN-I response was active in metastatic cancer cells in culture and markedly dampened when these cells formed primary tumors. Interestingly, the opposite was observed in non-metastatic cancer cells and tumors. Consistent with an active IFN-I response in culture, the metastatic cancer cells displayed elevated levels of cytosolic DNA from both mitochondria and ruptured micronuclei with concomitant activation of cGAS-STING signaling. Interestingly, decreased IFN-I-related gene expression in breast cancer biopsies correlated with an unfavourable prognosis in patients.

CONCLUSION

Our findings show that IFN-I response is dampened in the tumors with the metastatic ability and lower IFN-I expression predicts poor prognosis in triple-negative and HER2 enriched breast cancer patients. This study highlights the possibility of reactivating the IFN-I response as a potential therapeutic strategy in breast cancer. Video Abstract.