Current treatment landscape for patients with locally recurrent inoperable or metastatic triple-negative breast cancer: a systematic literature review

Tumor-intrinsic CDC42BPB confers resistance to anti-PD-1 immune checkpoint blockade in breast cancer

Immune checkpoint blockade has been used to treat breast cancer, but the clinical responses remain relatively poor. We have used the CRISPR-Cas9 kinome knockout library consisting of 763 kinase genes to identify tumor-intrinsic kinases conferring resistance to anti-PD-1 immune checkpoint blockade. We have identified the CDC42BPB kinase as a potential target to overcome the resistance to anti-PD-1 immune checkpoint blockade immunotherapy. We found that CDC42BPB is highly expressed in breast cancer patients who are non-responsive to immunotherapy. Furthermore, a small-molecule pharmacological inhibitor, BDP5290, which targets CDC42BPB, synergized with anti-PD-1 and enhanced tumor cell killing by promoting T cell proliferation in both in vitro and in vivo assays. Moreover, anti-PD-1-resistant breast cancer cells showed higher expression of CDC42BPB, and its inhibition rendered the resistant cells more susceptible to T cell killing in the presence of anti-PD-1. We also found that CDC42BPB phosphorylated AURKA, which in turn upregulated PD-L1 through cMYC. Our results have revealed a robust link between tumor-intrinsic kinase and immunotherapy resistance and have provided a rationale for a unique combination therapy of CDC42BPB inhibition and anti-PD-1 immunotherapy for breast cancer.

Datopotamab Deruxtecan in Advanced or Metastatic HR+/HER2- and Triple-Negative Breast Cancer: Results From the Phase I TROPION-PanTumor01 Study

PURPOSE

Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate consisting of a humanized antitrophoblast cell-surface antigen 2 (TROP2) monoclonal antibody linked to a potent, exatecan-derived topoisomerase I inhibitor payload via a plasma-stable, selectively cleavable linker.

PATIENTS AND METHODS

TROPION-PanTumor01 (ClinicalTrials.gov identifier: NCT03401385) is a phase I, dose-escalation, and dose-expansion study evaluating Dato-DXd in patients with previously treated solid tumors. The primary study objective was to assess the safety and tolerability of Dato-DXd. Secondary objectives included evaluation of antitumor activity and pharmacokinetics. Results from patients with advanced/metastatic hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer (BC) or triple-negative BC (TNBC) are reported.

RESULTS

At data cutoff (July 22, 2022), 85 patients (HR+/HER2- BC = 41, and TNBC = 44) had received Dato-DXd. The objective response rate by blinded independent central review was 26.8% (95% CI, 14.2 to 42.9) and 31.8% (95% CI, 18.6 to 47.6) for patients with HR+/HER2- BC and TNBC, respectively. The median duration of response was not evaluable in the HR+/HER2- BC cohort and 16.8 months in the TNBC cohort. The median progression-free survival in patients with HR+/HER2- BC and TNBC was 8.3 and 4.4 months, respectively. All-cause treatment-emergent adverse events (TEAEs; any grade, grade ≥3) were observed in 100% and 41.5% of patients with HR+/HER2- BC and 100% and 52.3% of patients with TNBC. Stomatitis was the most common TEAE (any grade, grade ≥3) in both HR+/HER2- BC (82.9%, 9.8%) and TNBC (72.7%, 11.4%) cohorts.

CONCLUSION

In patients with heavily pretreated advanced HR+/HER2- BC and TNBC, Dato-DXd demonstrated promising clinical activity and a manageable safety profile. Dato-DXd is currently being evaluated in phase III studies.

Capecitabine monotherapy as first-line treatment in advanced HER2-normal breast cancer - a nationwide, retrospective study

Background and purpose: Capecitabine can be used as first-line treatment for advanced breast cancer. However, real-world data on efficacy of capecitabine in this setting is sparse. The purpose of the study is to evaluate outcomes of patients with Human Epidermal Growth Factor Receptor (HER2)-normal advanced breast cancer treated with capecitabine monotherapy as first-line treatment.

MATERIAL AND METHODS

The study utilized the Danish Breast Cancer Group (DBCG) database and was conducted retrospectively across all Danish oncology departments. Inclusion criteria were female patients, with HER2-normal advanced breast cancer treated with capecitabine monotherapy as the first-line treatment from 2010 to 2020. The primary endpoints were overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 494 patients were included. Median OS was 16.4 months (95% confidence interval [CI]: 14.5-18.0), and median PFS was 6.0 months (95% CI: 5.3-6.7). Patients with estrogen receptor (ER)-positive disease had significantly longer OS (median: 22.8 vs. 10.5 months, p < 0.001) and PFS (median: 7.4 vs. 4.9 months, p = 0.003), when compared to ER-negative patients. Stratifying by age, patients under 45 years displayed a median PFS of 4.1 months, while those aged 45-70 years and over 70 years had median PFS of 5.7 and 7.2 months, respectively (p = 0.01).

INTERPRETATION

 In this nationwide study, the efficacy of capecitabine as a first-line treatment for HER2-normal advanced breast cancer is consistent with other, mainly retrospective, studies. However, when assessed against contemporary and newer treatments, its effectiveness appears inferior to alternative chemotherapies or targeted therapies.

Final Results From the Randomized Phase III ASCENT Clinical Trial in Metastatic Triple-Negative Breast Cancer and Association of Outcomes by Human Epidermal Growth Factor Receptor 2 and Trophoblast Cell Surface Antigen 2 Expression

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Sacituzumab govitecan (SG), a first-in-class anti-trophoblast cell surface antigen 2 (Trop-2) antibody-drug conjugate, demonstrated superior efficacy over single-agent chemotherapy (treatment of physician's choice [TPC]) in patients with metastatic triple-negative breast cancer (mTNBC) in the international, multicenter, phase III ASCENT study.Patients were randomly assigned 1:1 to receive SG or TPC until unacceptable toxicity/progression. Final efficacy secondary end point analyses and post hoc analyses of outcomes stratified by Trop-2 expression and human epidermal growth factor receptor 2 status are reported. Updated safety analyses are provided.In this final analysis, SG (n = 267) improved median progression-free survival (PFS; 4.8 v 1.7 months; hazard ratio (HR), 0.41 [95% CI, 0.33 to 0.52]) and median overall survival (OS; 11.8 v 6.9 months; HR, 0.51 [95% CI, 0.42 to 0.63]) over TPC (n = 262). SG improved PFS over TPC in each Trop-2 expression quartile (n = 168); a trend was observed for improved OS across quartiles. Overall, SG had a manageable safety profile, with ≤5% of treatment-related discontinuations because of adverse events and no treatment-related deaths. The safety profile was consistent across all subgroups.These data confirm the clinical benefit of SG over chemotherapy, reinforcing SG as an effective treatment option in patients with mTNBC in the second line or later.

Overall Survival and Prognostic Factors in Metastatic Triple-Negative Breast Cancer: A National Cancer Database Analysis

BACKGROUND

Metastatic triple-negative breast cancer (TNBC) is aggressive with poor median overall survival (OS) ranging from 8 to 13 months. There exists considerable heterogeneity in survival at the individual patient level. To better understand the survival heterogeneity and improve risk stratification, our study aims to identify the factors influencing survival, utilizing a large patient sample from the National Cancer Database (NCDB).

METHODS

Women diagnosed with metastatic TNBC from 2010 to 2020 in the NCDB were included. Demographic, clinicopathological, and treatment data and overall survival (OS) outcomes were collected. Kaplan-Meier curves were used to estimate OS. The log-rank test was used to identify OS differences between groups for each variable in the univariate analysis. For the multivariate analysis, the Cox proportional hazard model with backward elimination was used to identify factors affecting OS. Adjusted hazard ratios and 95% confidence intervals are presented.

RESULTS

In this sample, 2273 women had a median overall survival of 13.6 months. Factors associated with statistically significantly worse OS included older age, higher comorbidity scores, specific histologies, higher number of metastatic sites, presence of liver or other site metastases in those with only one metastatic site (excluding brain metastases), presence of cranial and extra-cranial metastases, lack of chemotherapy, lack of immunotherapy, lack of surgery to distant sites, lack of radiation to distant sites, and receipt of palliative treatment to alleviate symptoms. In the multivariate analysis, comorbidity score, histology, number of metastatic sites, immunotherapy, and chemotherapy had a statistically significant effect on OS.

CONCLUSIONS

Through NCDB analysis, we have identified prognostic factors for metastatic TNBC. These findings will help individualize prognostication at diagnosis, optimize treatment strategies, and facilitate patient stratification in future clinical trials.

Efficacy and safety of eribulin mesylate in patients with locally advanced or metastatic breast cancer previously treated with anthracycline/taxanes

BACKGROUND

This prospective real-world study aimed to assess the efficacy and safety of eribulin in the clinical practice against advanced breast cancer (ABC) in China.

PATIENTS AND METHODS

In this study, eligible patients with inoperable locally advanced or metastatic breast cancer who had experienced prior neo-/adjuvant or failed the palliative treatment with anthracycline/taxanes were included. Eribulin (1.4 mg/m2) was infused intravenously on Day 1 and Day 8 every 3 weeks until disease progression or intolerable toxicity occurred. The progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR), and safety of the treatment were assessed.

RESULTS

One hundred and thirty-four patients were enrolled. The median PFS (mPFS) was 4.3 months (95% CI: 0.3-15.4). The ORR and DCR was 32.1% and 79.1%, respectively. The mPFS of patients who received eribulin as first- or second-line treatment was significantly better than those who received eribulin as ≥3-line treatment (6.9 months [95% CI: 3.2-8.8] vs. 4.0 months [95% CI: 3.4-4.6], p = 0.006). The mPFS of patients with triple-negative, HER2-positive, and HER2(-)/HR(+) was 3.4 (95% CI: 2.7-4.1), 6.2 (95% CI: 2.3-10.1) and 5.0 months (95% CI: 4.1-5.9), respectively. HER2(+) patients had significantly longer PFS than TNBC patients (p = 0.022). Patients received combination therapy had a significantly longer mPFS than those who received eribulin monotherapy (5.0 months [95% CI 3.6-6.3] vs. 4.0 months [95% CI: 3.3-4.7] [p = 0.016]). Multivariate analysis revealed that MBC patients with a molecular typing of non-TNBC receiving eribulin as ≤2-line therapy and combination therapy had a low risk of disease progression. Neutropenia (33.58%), leukopenia (11.94%), and thrombocytopenia (4.48%) were the most common treatment-related adverse events.

CONCLUSION

Eribulin demonstrated effective clinical activity and a favorable tolerability profile in Chinese patients with ABC in the real-world. The efficacy and safety profile were consistent with those reported in previous randomized phase 3 trials.

Estradiol induces bone osteolysis in triple-negative breast cancer via its membrane-associated receptor ERα36

Triple-negative breast cancer (TNBC) is thought to be an estradiol-independent, hormone therapy-resistant cancer because of lack of estrogen receptor alpha 66 (ERα66). We identified a membrane-bound splice variant, ERα36, in TNBC cells that responds to estrogen (E2) and may contribute to bone osteolysis. We demonstrated that the MDA-MB-231 TNBC cell line, which expresses ERα36 similarly to MCF7 cells, is responsive to E2, forming osteolytic tumors in vivo. MDA-MB-231 cells activate osteoclasts in a paracrine manner. Conditioned media (CM) from MDA-MB-231 cells treated with bovine serum albumin-bound E2 (E2-BSA) increased activation of human osteoclast precursor cells; this was blocked by addition of anti-ERα36 antibody to the MDA-MB-231 cultures. Osteoclast activation and bone resorption genes were elevated in RAW 264.7 murine macrophages following treatment with E2-BSA-stimulated MDA-MB-231 CM. E2 and E2-BSA increased phospholipase C (PLC) and protein kinase C (PKC) activity in MDA-MB-231 cells. To examine the role of ERα36 signaling in bone osteolysis in TNBC, we used our bone-cancer interface mouse model in female athymic homozygous Foxn1nu mice. Mice with MDA-MB-231 tumors and treated with tamoxifen (TAM), E2, or TAM/E2 exhibited increased osteolysis, cortical bone breakdown, pathologic fracture, and tumor volume; the combined E2/TAM group also had reduced bone volume. These results suggest that E2 increased osteolytic lesions in TNBC through a membrane-mediated PLC/PKC pathway involving ERα36, which was enhanced by TAM, demonstrating the role of ERα36 and its membrane-associated signaling pathway in bone tumors. This work suggests that ERα36 may be a potential therapeutic target in patients with TNBC.

TROPION-Breast03: a randomized phase III global trial of datopotamab deruxtecan ± durvalumab in patients with triple-negative breast cancer and residual invasive disease at surgical resection after neoadjuvant therapy

Background

Despite advances in the treatment of early triple-negative breast cancer (TNBC), patients with residual invasive disease after neoadjuvant therapy have a high risk of disease recurrence and worse survival outcomes than those who have pathological complete response (pCR). Improving outcomes in early TNBC remains an unmet need requiring new adjuvant treatment approaches. Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate comprising a humanized anti-trophoblast cell-surface antigen 2 immunoglobulin G1 (IgG1) monoclonal antibody attached via a plasma-stable, cleavable linker to a potent topoisomerase I inhibitor payload, with activity observed in advanced TNBC.

Objectives

TROPION-Breast03 is an ongoing phase III study evaluating the efficacy and safety of Dato-DXd alone or combined with durvalumab versus standard-of-care therapy as adjuvant treatment in patients with stage I-III TNBC with residual invasive disease at surgical resection following neoadjuvant treatment.

Methods and design

Eligible patients, aged ⩾18 years, will be randomized in a 2:1:2 ratio to receive Dato-DXd [6 mg/kg intravenously (IV) every 3 weeks (Q3W); eight cycles] and durvalumab (1120 mg IV Q3W; nine cycles), Dato-DXd monotherapy (6 mg/kg IV Q3W), or investigator's choice of therapy (ICT; capecitabine, pembrolizumab, or capecitabine and pembrolizumab). The primary endpoint is invasive disease-free survival (iDFS) for Dato-DXd and durvalumab versus ICT. Key secondary endpoints include safety, distant disease-free survival, and overall survival for Dato-DXd and durvalumab versus ICT and iDFS for Dato-DXd monotherapy versus ICT.

Ethics

TROPION-Breast03 will be approved by the independent ethics committees or institutional review boards at each study site. All study participants will provide written informed consent.

Discussion

TROPION-Breast03 will help define the potential role of Dato-DXd in the treatment of patients with early-stage TNBC who do not have pCR after neoadjuvant therapy.

Trial registration

ClinicalTrials.gov identifier: NCT05629585 (registration date: 29 November 2022).

Nanoscale strides: exploring innovative therapies for breast cancer treatment

Breast cancer (BC) is a predominant malignancy in women that constitutes approximately 30% of all cancer cases and has a mortality rate of 14% in recent years. The prevailing therapies include surgery, chemotherapy, and radiotherapy, each with its own limitations and challenges. Despite oral or intravenous administration, there are numerous barriers to accessing anti-BC agents before they reach the tumor site, including physical, physiological, and biophysical barriers. The complexity of BC pathogenesis, attributed to a combination of endogenous, chronic, intrinsic, extrinsic and genetic factors, further complicates its management. Due to the limitations of existing cancer treatment approaches, there is a need to explore novel, efficacious solutions. Nanodrug delivery has emerged as a promising avenue in cancer chemotherapy, aiming to enhance drug bioavailability while mitigating adverse effects. In contrast to conventional chemotherapy, cancer nanotechnology leverages improved permeability to achieve comprehensive disruption of cancer cells. This approach also presented superior pharmacokinetic profiles. The application of nanotechnology in cancer therapeutics includes nanotechnological tools, but a comprehensive review cannot cover all facets. Thus, this review concentrates specifically on BC treatment. The focus lies in the successful implementation of systematic nanotherapeutic strategies, demonstrating their superiority over conventional methods in delivering anti-BC agents. Nanotechnology-driven drug delivery holds immense potential in treating BC. By surmounting multiple barriers and capitalizing on improved permeability, nanodrug delivery has demonstrated enhanced efficacy and reduced adverse effects compared to conventional therapies. This review highlights the significance of systematic nanotherapy approaches, emphasizing the evolving landscape of BC management.

Subgroup analyses from the phase 3 ASCENT study of sacituzumab govitecan in metastatic triple-negative breast cancer

In this post hoc analysis of the ASCENT study, we compared outcomes with sacituzumab govitecan (SG) vs single-agent chemotherapy in clinically important subgroups of patients with metastatic triple-negative breast cancer (mTNBC). Patients with mTNBC refractory to/relapsing after ≥2 prior chemotherapies (≥1 in the metastatic setting) were randomized 1:1 to receive SG or treatment of physician's choice (TPC) until unacceptable toxicity/progression. The primary endpoint was progression-free survival (PFS) per RECIST 1.1 by central review in patients without brain metastases. Patients with brain metastases were allowed if metastases were stable ≥4 weeks. In the intention-to-treat (ITT) population, 19% of patients were age ≥65 years; 12% were Black, and 12% had brain metastases. SG improved PFS and overall survival (OS), respectively, vs TPC in patients age ≥65 years (7.1 vs 2.4 months and 14.7 vs 8.9 months), or of Black race (5.4 vs 2.2 months and 13.8 vs 8.5 months), consistent with outcomes in the ITT population. Patients with brain metastases had numerically higher median PFS with SG vs TPC, but median OS was similar between treatment groups. SG was well tolerated and had a manageable safety profile consistent with the full safety population across all subgroups; neutropenia and diarrhea were the most common treatment-emergent adverse events. These findings confirm the meaningful clinical benefit of SG vs standard chemotherapy in patient subgroups with high unmet needs. SG should be considered an effective and safe treatment option for patients with mTNBC eligible for second-line or later therapy. ClinicalTrials.gov Number: NCT02574455.

Induced electric fields inhibit breast cancer growth and metastasis by modulating the immune tumor microenvironment

Despite tremendous advances in oncology, metastatic triple-negative breast cancer remains difficult to treat and manage with established therapies. Here, we show in mice with orthotopic triple-negative breast tumors that alternating (100 kHz), and low intensity (<1 mV/cm) induced electric fields (iEFs) significantly reduced primary tumor growth and distant lung metastases. Non-contact iEF treatment can be delivered safely and non-invasively in vivo via a hollow, rectangular solenoid coil. We discovered that iEF treatment enhances anti-tumor immune responses at both the primary breast and secondary lung sites. In addition, iEF reduces immunosuppressive TME by reducing effector CD8+ T cell exhaustion and the infiltration of immunosuppressive immune cells. Furthermore, iEF treatment reduced lung metastasis by increasing CD8+ T cells and reducing immunosuppressive Gr1+ neutrophils in the lung microenvironment. We also observed that iEFs reduced the metastatic potential of cancer cells by inhibiting epithelial-to-mesenchymal transition. By introducing a non-invasive and non-toxic electrotherapeutic for inhibiting metastatic outgrowth and enhancing anti-tumor immune response in vivo, treatment with iEF technology could add to a paradigm-shifting strategy for cancer therapy.

Efficacy and safety of first-line treatment for metastatic triple-negative breast cancer: A network meta-analysis

Background

Metastatic triple-negative breast cancer (mTNBC) is an aggressive histological subtype with poor prognosis. Several first-line treatments are currently available for mTNBC. This study conducted a network meta-analysis to compare these first-line regimens and to determine the regimen with the best efficacy.

Methods

A systematic search of PubMed, EMBASE, the Cochrane Central Register of Controlled Bases, and minutes of major conferences was performed. Progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) were analyzed via network meta-analysis using the R software (R Core Team, Vienna, Austria). The efficacy of the treatment regimens was compared using hazard ratios and 95% confidence intervals.

Results

A total of 29 randomized controlled trials involving 4607 patients were analyzed. The ranking was based on the surface under the cumulative ranking curve. Network meta-analysis results showed that cisplatin combined with nab-paclitaxel or paclitaxel was superior to docetaxel plus capecitabine in terms of PFS and ORR. For programmed death-ligand 1 (PD-L1) and breast cancer susceptibility gene (BRCA) mutation-positive tumors, atezolizumab/pembrolizumab combined with nab-paclitaxel and talazoparib was superior to docetaxel plus capecitabine. No significant difference was observed among the treatments in OS. Neutropenia, diarrhea, and fatigue were common serious adverse events.

Conclusion

Cisplatin combined with nab-paclitaxel or paclitaxel is the preferred first-line treatment for mTNBC. For PD-L1 and BRCA mutation-positive tumors, atezolizumab/pembrolizumab combined with nab-paclitaxel and talazoparib is an effective treatment option. Neutropenia, diarrhea, and fatigue are frequently occurring serious adverse events.

Optimal response to tislelizumab plus chemotherapy in metastatic triple-negative breast cancer: a case report and literature review

Metastatic triple-negative breast cancer (mTNBC) has the worst prognosis among breast cancer subtypes. Immune checkpoint inhibitors (ICIs) plus chemotherapy have promising survival benefits. Herein, we report a 51-year-old woman whose metastatic lesions were diagnosed as triple-negative subtype and who received tislelizumab plus eribulin treatment and achieved excellent efficacy. To our knowledge, this study is the first attempt to present tislelizumab in combination with eribulin for mTNBC treatment. New treatments resulting in prolonged survival and durable clinical responses would benefit mTNBC patients. Then, we summarize the possible influencing factors of the interaction between tislelizumab and eribulin.

Third-line Treatment for Metastatic Triple-negative Breast Cancer: A Systematic Review and Network Meta-analysis

OBJECTIVE

Metastatic triple-negative breast cancer (mTNBC) is an invasive histologic subtype with a poor prognosis and rapid progression. Currently, there is no standard therapy for the third-line treatment of mTNBC. In this study, we conducted a network meta-analysis to compare regimens and determine treatment outcomes.

METHODS

We performed a systematic search of PubMed, EMBASE, the Cochrane Central Register of Controlled Bases, and the minutes of major conferences. Progression-free survival, overall survival, and objective response rate were analyzed through network meta-analysis using the R software (R Core Team). The efficacy of the treatment regimens was compared using hazard ratios, odds ratios, and 95% CIs.

RESULTS

We evaluated 15 randomized controlled trials involving 6,010 patients. Compared with the physician's choice treatment, sacituzumab govitecan showed significant advantages in progression-free survival and overall survival, with hazard ratio values of 0.41 (95% CI: 0.32-0.52) and 0.48 (95% CI, 0.39-0.60). In terms of objective response rate, sacituzumab govitecan is the best-performing therapy (odds ratio: 10.82; 95% CI: 5.58-20.97). Adverse events among grades 3 to 5 adverse reactions, the incidence of neutropenia and leukopenia in each regimen was higher, whereas the incidence of fever, headache, hypertension, and rash was lower.

CONCLUSION

Compared with the treatment of the physician's choice, sacituzumab govitecan appears more efficacious and is the preferred third-line treatment for mTNBC.

Breast Cancer Immunity: It is TIME for the Next Chapter

Our ability to interrogate the tumor immune microenvironment (TIME) at an ever-increasing granularity has uncovered critical determinants of disease progression. Not only do we now have a better understanding of the immune response in breast cancer, but it is becoming possible to leverage key mechanisms to effectively combat this disease. Almost every component of the immune system plays a role in enabling or inhibiting breast tumor growth. Building on early seminal work showing the involvement of T cells and macrophages in controlling breast cancer progression and metastasis, single-cell genomics and spatial proteomics approaches have recently expanded our view of the TIME. In this article, we provide a detailed description of the immune response against breast cancer and examine its heterogeneity in disease subtypes. We discuss preclinical models that enable dissecting the mechanisms responsible for tumor clearance or immune evasion and draw parallels and distinctions between human disease and murine counterparts. Last, as the cancer immunology field is moving toward the analysis of the TIME at the cellular and spatial levels, we highlight key studies that revealed previously unappreciated complexity in breast cancer using these technologies. Taken together, this article summarizes what is known in breast cancer immunology through the lens of translational research and identifies future directions to improve clinical outcomes.

Co-assembly of polymeric conjugates sensitizes neoadjuvant chemotherapy of triple-negative breast cancer with reduced systemic toxicity

Rational design of polymeric conjugates could greatly potentiate the combination therapy of solid tumors. In this study, we designed and prepared two polymeric conjugates (HT-DTX and PEG-YC-1), whereas the drugs were attached to the PEG via a linker sensitive to cathepsin B, over-expressed in TNBC. Stable nanostructures were formed by these two polymer prodrug conjugates co-assembly (PPCC). The stimuli-responsiveness of PPCC was confirmed, and the size shrinkage under tumor microenvironment would facilitate the penetration of PPCC into tumor tissue. In vitro experiments revealed the molecular mechanism for the synergistic effect of the combination of DTX and YC-1. Moreover, the systemic side effects were significantly diminished since the biodistribution of PPCC was improved after i.v. administration in vivo. In this context, the co-assembled nano-structural approach could be employed for delivering therapeutic drugs with different mechanisms of action to exert a synergistic anti-tumor effect against solid tumors, including triple-negative breast cancer. STATEMENT OF SIGNIFICANCE.

Advances in the study of marketed antibody-drug Conjugates (ADCs) for the treatment of breast cancer

Breast cancer continues to have a high incidence rate among female malignancies. Despite significant advancements in treatment modalities, the heterogeneous nature of breast cancer and its resistance to various therapeutic approaches pose considerable challenges. Antibody-drug conjugates (ADCs) effectively merge the specificity of antibodies with the cytotoxicity of chemotherapeutic agents, offering a novel strategy for precision treatment of breast cancer. Notably, trastuzumab emtansine (T-DM1) has provided a new therapeutic option for HER2-positive breast cancer patients globally, especially those resistant to conventional treatments. The development of trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) has further broadened the applicability of ADCs in breast cancer therapy, presenting new hopes for patients with low HER2 expression and triple-negative breast cancer. However, the application of ADCs presents certain challenges. For instance, their treatment may lead to adverse reactions such as interstitial lung disease, thrombocytopenia, and diarrhea. Moreover, prolonged treatment could result in ADCs resistance, complicating the therapeutic process. Economically, the high costs of ADCs might hinder their accessibility in low-income regions. This article reviews the structure, mechanism of action, and clinical trials of commercially available ADCs for breast cancer treatment, with a focus on the clinical trials of the three drugs, aiming to provide insights for clinical applications and future research.

Challenges in HER2-low breast cancer identification, detection, and treatment

Recently, human epidermal growth factor receptor 2 (HER2)-low breast cancer (BC) has emerged as a novel subset within the category of HER2-negative BC, prompting a reassessment of the immunohistochemical negative scores of 0, 1+, and the 2+/in situ hybridization (ISH) negative phenotype. Recent clinical trials have provided compelling evidence of the substantial clinical advantages offered by novel antibody-drug conjugates (ADCs) that target HER2 in the treatment of these specific tumor cohorts. Notably, trastuzumab deruxtecan (T-Dxd), an ADC that specifically targets HER2, has recently received approval from the US Food and Drug Administration as the inaugural targeted therapeutic option for HER2-low BC. However, the classification of HER2-low BC as a distinct subtype, the methods for detecting HER2-low BC, and the optimal treatment approach for HER2-low BC remain subjects of ongoing debate and lack consensus. This comprehensive review aims to address these pertinent concerns, offering insights into the nuanced tumor biology underlying HER2-low BC and critically analyzing the current treatment pathways available. By synthesizing available evidence, the objective is to contribute to an enhanced understanding of HER2-low BC, providing a foundation for more informed clinical decisions and further advancements in tailored therapeutic approaches. As the medical community navigates these uncertainties, this review seeks to consolidate existing knowledge, fostering a collective effort toward establishing consensus in the diagnosis and treatment of HER2-low BC.

Phase II Clinical Trial of Pembrolizumab and Chemotherapy Reveals Distinct Transcriptomic Profiles by Radiologic Response in Metastatic Triple-Negative Breast Cancer

PURPOSE

A single arm, phase II trial of carboplatin, nab-paclitaxel, and pembrolizumab (CNP) in metastatic triple-negative breast cancer (mTNBC) was designed to evaluate overall response rate (ORR), progression-free survival (PFS), duration of response (DOR), safety/tolerability, overall survival (OS), and identify pathologic and transcriptomic correlates of response to therapy.

PATIENTS AND METHODS

Patients with ≤2 prior therapies for metastatic disease were treated with CNP regardless of tumor programmed cell death-ligand 1 status. Core tissue biopsies were obtained prior to treatment initiation. ORR was assessed using a binomial distribution. Survival was analyzed via the Kaplan-Meier method. Bulk RNA sequencing was employed for correlative studies.

RESULTS

Thirty patients were enrolled. The ORR was 48.0%: 2 (7%) complete responses (CR), 11 (41%) partial responses (PR), and 8 (30%) stable disease (SD). The median DOR for patients with CR or PR was 6.4 months [95% confidence interval (CI), 4-8.5 months]. For patients with CR, DOR was >24 months. Overall median PFS and OS were 5.8 (95% CI, 4.7-8.5 months) and 13.4 months (8.9-17.3 months), respectively. We identified unique transcriptomic landscapes associated with each RECIST category of radiographic treatment response. In CR and durable PR, IGHG1 expression was enriched. IGHG1high tumors were associated with improved OS (P = 0.045) and were concurrently enriched with B cells and follicular helper T cells, indicating IGHG1 as a promising marker for lymphocytic infiltration and robust response to chemo-immunotherapy.

CONCLUSIONS

Pretreatment tissue sampling in mTNBC treated with CNP reveals transcriptomic signatures that may predict radiographic responses to chemo-immunotherapy.

Sacituzumab Govitecan as a Second-Line Treatment in Relapsed/Refractory Metastatic Triple-Negative Breast Cancer Patients: A Systematic Review and Meta-analysis

BACKGROUND

Chemotherapy, the only treatment option for metastatic triple-negative breast cancer (mTNBC), showed decreased survival rates. Trophoblast cell surface antigen-2 (Trop-2) could be a possible target for antibody-drug conjugates (ADCs).

OBJECTIVE

Sacituzumab govitecan (SG), an anti-Trop-2 ADC for pretreating relapsed/refractory mTNBC patients, was studied to know the efficacy and safety profile of the drug in mTNBC.

METHODS

The present review searched MEDLINE (via PubMed), WHO Clinical Trial Registry, Clinical Trials.gov, and Cochrane Central Register of Controlled Trials until December 25, 2022. The studies searched comprised randomized trials and observational studies (retrospective [case-control, cross-sectional] and prospective [cohort designs]). Efficacy assessment was performed in terms of complete response (CR), partial response (PR), objective response rate (ORR), stable disease (SD), progressive disease (PD), and clinical benefit rate (CBR), and safety in terms of adverse events.

RESULTS

The overall random-effects pooled prevalence of CR was 4.9 (95% CI: 3.2-7.1), PR was 35.6 (95% CI: 31.5-39.9), ORR was 6.8 (95% CI: 5.9-7.8), SD was 8.0 (95% CI: 6.7-9.4), PD was 5.1 (95% CI: 4.1-6.3), and CBR was 13.4 (95% CI: 11.8-15.1). Adverse events associated with the drug were neutropenia, fatigue, anemia, nausea, and others.

CONCLUSION AND RELEVANCE

This is the first meta-analysis conducted in relapsed/refractory mTNBC patients and found that SG is efficacious but associated with some adverse effects that are related to exposure to the drug. The application of these results will allow clinicians to use SG in the management of patients with mTNBC.

Impact of pembrolizumab versus chemotherapy on health-related quality of life in patients with metastatic triple-negative breast cancer: results from the phase 3 randomised KEYNOTE-119 study

BACKGROUND

In KEYNOTE-119 (ClinicalTrials.gov, NCT02555657), overall survival (primary end-point) was similar between pembrolizumab and chemotherapy in patients with previously treated metastatic triple-negative breast cancer (TNBC), although the pembrolizumab treatment effect increased with tumour PD-L1 expression. We report results of prespecified health-related quality of life (HRQoL) analyses from KEYNOTE-119.

METHODS

Eligible patients were randomised 1:1 to pembrolizumab 200 mg Q3W intravenously for up to 35 cycles or treatment of physician's choice per local/country guidelines. Prespecified exploratory end-points were the change from baseline in HRQoL (EORTC QLQ-C30, QLQ-BR23) and to characterise utilities (EQ-5D-3L). Time to deterioration (TTD) was the time from start of treatment to first onset of a ≥10-point worsening from baseline.

RESULTS

HRQoL analyses included 187 patients with tumour PD-L1 combined positive score (CPS) ≥10. Changes from baseline at 6 weeks (primary analysis time point) were directionally better with pembrolizumab versus chemotherapy for QLQ-C30 GHS/QoL (between-group difference in least-squares mean scores of 4.21 [95% CI, -1.38 to 9.80]), QLQ-C30 functional scales (physical, role, cognitive, social), QLQ-C30 symptom scales/items (fatigue, nausea/vomiting, dyspnoea, appetite loss), and QLQ-BR23 symptom scales/items (systemic therapy side-effects, upset by hair loss). Median TTD was directionally longer for pembrolizumab versus chemotherapy for QLQ-C30 QHS/QoL (4.3 versus 1.7 months), QLQ-C30 nausea/vomiting (7.7 versus 4.8 months), and QLQ-BR23 systemic therapy side-effects (6.1 versus 3.4 months). Minimal treatment differences were observed for other HRQoL end-points.

CONCLUSIONS

HRQoL results were consistent with clinical outcomes and appeared to be driven by results for patients with tumour PD-L1 CPS ≥10.

Understanding the promising role of antibody drug conjugates in breast and ovarian cancer

A nascent category of anticancer therapeutic drugs called antibody-drug conjugates (ADCs) relate selectivity of aimed therapy using chemotherapeutic medicines with high cytotoxic power. Progressive linker technology led to the advancement of more efficacious and safer treatments. It offers neoteric as well as encouraging therapeutic strategies for treating cancer. ADCs selectively administer a medication by targeting antigens which are abundantly articulated on the membrane surface of tumor cells. Tumor-specific antigens are differently expressed in breast and ovarian cancers and can be utilized to direct ADCs. Compared to conventional chemotherapeutic drugs, this approach enables optimal tumor targeting while minimizing systemic damage. A cleavable linker improves the ADCs because it allows the toxic payload to be distributed to nearby cells that do not express the target protein, operating on assorted tumors with dissimilar cell aggregation. Presently fifteen ADCs are being studied in breast and ovarian carcinoma preclinically, and assortment of few have already undergone promising early-phase clinical trial testing. Furthermore, Phase I and II studies are investigating a wide variety of ADCs, and preliminary findings are encouraging. An expanding sum of ADCs will probably become feasible therapeutic choices as solo agents or in conjunction with chemotherapeutic agents. This review accentuates the most recent preclinical findings, pharmacodynamics, and upcoming applications of ADCs in breast and ovarian carcinoma.

Real-World Survival and Treatment Regimens Across First- to Third-Line Treatment for Advanced Triple-Negative Breast Cancer

Background

Metastatic triple-negative breast cancer (mTNBC) is an aggressive subtype of breast cancer with poor survival. Currently, the literature lacks comprehensive real-world evidence on locally recurrent and mTNBC patients. To validate the optimal treatment for patients with mTNBC, real-world evidence in combination with data from clinical trials must be evaluated as complementary.

Objectives

The objective of the study is to examine outcomes and treatment patterns of patients with advanced triple-negative breast cancer (TNBC) utilizing real-world data of patients from all oncology sites across Denmark.

Design

This is a retrospective, non-interventional, multi-site, population-based observational study conducted across all oncology departments in Denmark.

Methods

We included all women diagnosed with metastatic or locally recurrent TNBC from January 1, 2017, to December 31, 2019, using the national Danish Breast Cancer Group database. The primary endpoints were overall survival (OS) and progression-free survival (PFS) in the first to third treatment line.

Results

The study included 243 women diagnosed with metastatic or recurrent TNBC. The median OS (mOS) was 11.6 months after the first line of treatment, 6.5 months after the second line, and 6.5 months after the third line. De novo mTNBC was associated with shorter OS (mOS: 8.3 vs 14.2 months), and those with a relapse within 18 months of primary diagnosis had shorter OS than those with a relapse after 18 months (mOS: 10.0 vs 18.2). In the first line, taxane was the preferred choice of treatment for patients with de novo mTNBC, whereas capecitabine was preferred for patients with recurrent TNBC.

Conclusions

This real-world, nationwide study demonstrated poor OS among patients with metastatic or recurrent TNBC, with a mOS of 11.6 months (95% CI, 9.9-17.3). Patients who presented with de novo mTNBC or who had a relapse of their breast cancer within 18 months of primary diagnosis had shorter OS.

Registration

The study was registered and approved by the Danish Capital Regions research overview (P-2021-605).

Effect of 1 H-NMR serum lipoproteins on immunotherapy response in advanced triple-negative breast cancer patients

We previously reported the results of a phase II trial of anti-PD-1 antibody plus anti-vascular endothelial growth factor receptor 2 inhibitors and eribulin in heavily pretreated advanced triple-negative breast cancer with a favorable objective response rate (ORR) of 37.0% (NCT04303741). Here we report updated survival outcomes and serum metabolite changes of the study. Proton nuclear magnetic resonance spectroscopy was used to detect metabolite dynamics and explore biomarkers for response. We found that treatment-sensitive patients had higher very low-density lipoprotein-related metabolite expression at baseline. A lipid proteomics model consisting of six metabolites predicted ORR and progression-free survival at 6 months with area under the receiver operating characteristic curves of 0.88 and 0.87, respectively. Serum asparagine and sarcosine concentrations were significantly higher after treatment in treatment-resistant patients. In conclusion, we constructed a model consisting of six metabolites to identify patients who benefit more from the triplet treatment, and asparagine and sarcosine may be associated with treatment resistance.

Current perspectives and trends in nanoparticle drug delivery systems in breast cancer: bibliometric analysis and review

The treatment of breast cancer (BC) is a serious challenge due to its heterogeneous nature, multidrug resistance (MDR), and limited therapeutic options. Nanoparticle-based drug delivery systems (NDDSs) represent a promising tool for overcoming toxicity and chemotherapy drug resistance in BC treatment. No bibliometric studies have yet been published on the research landscape of NDDS-based treatment of BC. In this review, we extracted data from 1,752 articles on NDDS-based treatment of BC published between 2012 and 2022 from the Web of Science Core Collection (WOSCC) database. VOSviewer, CiteSpace, and some online platforms were used for bibliometric analysis and visualization. Publication trends were initially observed: in terms of geographical distribution, China and the United States had the most papers on this subject. The highest contributing institution was Sichuan University. In terms of authorship and co-cited authorship, the most prolific author was Yu Zhang. Furthermore, Qiang Zhang and co-workers have made tremendous achievements in the field of NDDS-based BC treatment. The article titled "Nanomedicine in cancer therapy: challenges, opportunities, and clinical applications" had the most citations. The Journal of Controlled Release was one of the most active publishers in the field. "Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries" was the most cited reference. We also analysed "hot" and cutting-edge research for NDDSs in BC treatment. There were nine topic clusters: "tumour microenvironment," "nanoparticles (drug delivery)," "breast cancer/triple-negative breast cancer," "combination therapy," "drug release (pathway)," "multidrug resistance," "recent advance," "targeted drug delivery", and "cancer nanomedicine." We also reviewed the core themes of research. In summary, this article reviewed the application of NDDSs in the treatment of BC.

Immunogenicity and efficacy of pembrolizumab and doxorubicin in a phase I trial for patients with metastatic triple-negative breast cancer

Currently there is a limited understanding for the optimal combination of immune checkpoint inhibitor and chemotherapy for patients with metastatic triple-negative breast cancer (mTNBC). Here we evaluate the safety, efficacy, and immunogenicity of a phase I trial for patients with mTNBC treated with pembrolizumab plus doxorubicin. Patients without prior anthracycline use and 0-2 lines of prior systemic chemotherapies received pembrolizumab and doxorubicin every 3 weeks for 6 cycles followed by pembrolizumab maintenance until disease progression or intolerance. The primary objectives were safety and objective response rate per RECIST 1.1. Best responses included one complete response (CR), five partial responses (PR), two stable disease (SD), and one progression of disease (PD). Overall response rate was 67% (95% CI 13.7%, 78.8%) and clinical benefit rate at 6 months was 56% (95% CI 21.2%, 86.3%). Median PFS was 5.2 months (95% CI 4.7, NA); median OS was 15.6 months (95% CI 13.3, NA). Grade 3-4 AEs per CTCAE 4.0 were neutropenia n = 4/10 (40%), leukopenia n = 2/10 (20%), lymphopenia n = 2/10 (20%), fatigue n = 2/10 (20%), and oral mucositis n = 1/10 (10%). Immune correlates showed increased frequencies of circulating CD3 + T cells (p = 0.03) from pre-treatment to cycle 2 day 1 (C2D1). An expansion of a proliferative exhausted-like PD-1 + CD8 + T cell population was identified in 8/9 patients, and exhausted CD8 + T cells were significantly expanded from pre-treatment to C2D1 in the patient with CR (p = 0.01). In summary, anthracycline-naïve patients with mTNBC treated with the combination of pembrolizumab and doxorubicin showed an encouraging response rate and robust T cell response dynamics.Trial registration: NCT02648477.

Hope and Hype around Immunotherapy in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) holds a poor prognosis compared to other breast cancer subtypes, and the development of new effective treatment strategies is an unmet medical need. TNBC has traditionally been considered not amenable to treatment with targeted agents due to a lack of actionable targets. Therefore, chemotherapy has remained the mainstay of systemic treatment for many decades. The advent of immunotherapy raised very hopeful expectations in TNBC, possibly due to higher levels of tumor-infiltrating lymphocytes, PD-L1 expression and tumor mutational burden compared to other breast cancer subtypes, that predict an effective anti-tumor immune-engagement. The results of clinical trials testing immunotherapy in TNBC led to the approval of the combination of immune checkpoint inhibitors and chemotherapy in both early and advanced settings. However, some open questions about the use of immunotherapy in TNBC still exist. These include a deeper understanding of the heterogeneity of the disease, identification of reliable predictive biomarkers of response, determination of the most appropriate chemotherapy backbone and appropriate management of potential long-term immune-related adverse events. In this review we aim to examine the available evidence on the use of immunotherapy strategies in both early and advanced TNBC, to critically discuss some of the limitations encountered in clinical research and to summarize data on novel promising immunotherapeutic strategies beyond PD-(L)1 blockade that have been investigated in the most recent trials.

A Phase IIb, single arm, multicenter trial of sacituzumab govitecan in Chinese patients with metastatic triple-negative breast cancer who received at least two prior treatments

Refractory or relapsing metastatic triple-negative breast cancer (mTNBC) has a poor prognosis. Sacituzumab govitecan (SG) is a novel antibody-drug conjugate, targeting human trophoblast cell-surface antigen 2 (Trop-2). This is the first report of SG's efficacy and safety in Chinese patients with mTNBC. EVER-132-001 (NCT04454437) was a multicenter, single-arm, Phase IIb study in Chinese patients with mTNBC who failed ≥2 prior chemotherapy regimens. Eligible patients received 10 mg/kg SG on Days 1 and 8 of each 21-day treatment cycle, until disease progression/unacceptable toxicity. The primary endpoint was objective response rate (ORR) assessed by the Independent Review Committee. Secondary endpoints included: duration of response (DOR), clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS) and safety. Eighty female Chinese patients (median age 47.6 years; range 24-69.9 years) received ≥1 SG dose with a median of 8 treatment cycles by the cutoff date (August 6, 2021). Median number of prior systemic cancer treatments was 4.0 (range 2.0-8.0). ORR and CBR were reported 38.8% (95% confidence interval [CI]: 28.06-50.30) and 43.8% (95% CI, 32.68-55.30) of patients, respectively. The median PFS was 5.55 months (95% CI, 4.14-N/A). SG-related Grade ≥3 treatment-emergent adverse events (TEAEs) were reported in 71.3%, the most common were neutrophil count decreased (62.5%), white blood cell count decreased (48.8%) and anemia (21.3%); 6.3% discontinued SG because of TEAEs. SG demonstrated substantial clinical activity in heavily pretreated Chinese patients with mTNBC. The observed safety profile was generally manageable.

Tissue factor overexpression in triple-negative breast cancer promotes immune evasion by impeding T-cell infiltration and effector function

Triple-negative breast cancer (TNBC) remains a most deadly human malignancy with limited response to chemotherapy, targeted therapy and immunotherapy. Tumor immunoenvironment plays an increasingly important role in therapy outcome. Tissue factor (TF) is the target of the FDA-approved ADC Tivdak. HuSC1-39 is the parent antibody of MRG004A, a clinical stage TF-ADC (NCT04843709). Here, we employed HuSC1-39 (termed "anti-TF") to investigate the role of TF in regulating immune-tolerance in TNBC. We found that patients with aberrant TF expression had a poor prognosis and low immune effector cell infiltration, characterizing as "cold tumor". In the 4T1 TNBC syngeneic mouse model, knockout of tumor cell TF inhibited tumor growth and increased tumor infiltration of effector T cell, which was not dependent on the clotting inhibition. In an immune-reconstituted M-NSG mouse model of TNBC, anti-TF inhibited tumor growth, which was further enhanced by a dual-targeting anti-TF&TGFβR fusion protein. There were diminished P-AKT and P-ERK signaling and profound tumor cell death in treated tumors. Transcriptome analyses and immunohistochemistry revealed a dramatically improved tumor immunoenvironment including the increase of effector T cells, decrease of Treg cells and the transformation of tumor into "hot tumor". Moreover, employing qPCR analysis and T cell culture, we further demonstrated that TF expression in tumor cells is sufficient to block the synthesis and secretion of T cell-recruiting chemokine CXCL9/10/11. Treatment of TF-high TNBC cells with anti-TF or TF-knockout all stimulated CXCL9/10/11 production, promoted T cell migration and effector function. Thus, we have identified a new mechanism of TF in TNBC tumor progression and therapy resistance.

Real-world outcomes in metastatic HR+/HER2-, HER2+ and triple negative breast cancer after start of first-line therapy

Aim: We evaluated outcomes of first-line (1L) treatment of metastatic breast cancer by biomarker subtype in the community setting over the last decade. Methods: Eligible patients (n = 1518) were female, ≥18 years, diagnosed with metastatic breast cancer 2010 or later, had documented HR+/HER2-, HER2+, or triple negative breast cancer (TNBC); and initiated 1L therapy. Kaplan-Meier and Cox methods were used to evaluate 1L real-world progression-free survival and overall survival from start of 1L. Results: TNBC was diagnosed at an earlier stage and had higher tumor grade at initial diagnosis. 1L real-world progression-free survival and overall survival from start of 1L were shorter for TNBC than HR+/HER2- or HER2+. Conclusion: Overall prognosis for patients with metastatic TNBC remains poor, and new therapies are needed to improve clinical outcomes.

Dynamic tumor microenvironment, molecular heterogeneity, and distinct immunologic portrait of triple-negative breast cancer: an impact on classification and treatment approaches

Heterogeneity of the tumor microenvironment (TME) and the lack of a definite targetable receptor in triple-negative breast cancer (TNBC) has carved a niche for this cancer as a particularly therapeutically challenging form of breast cancer. However, recent advances in high-throughput genomic analysis have provided new insights into the unique microenvironment and defining characteristics of various subsets of TNBC. This improved understanding has contributed to the development of novel therapeutic strategies including targeted therapies such as PARP inhibitors and CDK inhibitors. Moreover, the recent FDA approval of the immune checkpoint inhibitor against programmed cell death protein 1 (PD-1), pembrolizumab and atezolizumab, holds the promise of improving the quality of life and increasing the overall survival of TNBC patients. This recent approval is one of the many therapeutically novel strategies that are currently being exploited in clinical trials toward eventual contribution to the oncologist's toolbox against TNBC. In this review, we comprehensively discuss TNBC's distinct TME and its immunophenotype. Furthermore, we highlight the histological and molecular classification of this cancer. More importantly, we describe how these characteristics and classifications contribute to the current standards of care and how they steer the development of newer and more targeted therapies toward achieving peak therapeutic goals in the treatment of TNBC.

One New Acid-Activated Hybrid Anticancer Peptide by Coupling with a Desirable pH-Sensitive Anionic Partner Peptide

Anticancer peptides (ACPs) are promising antitumor resources, and developing acid-activated ACPs as more effective and selective antitumor drugs would represent new progress in cancer therapy. In this study, we designed a new class of acid-activated hybrid peptides LK-LE by altering the charge shielding position of the anionic binding partner LE based on the cationic ACP LK and investigated their pH response, cytotoxic activity, and serum stability, in hoping to achieve a desirable acid-activatable ACP. As expected, the obtained hybrid peptides could be activated and exhibit a remarkable antitumor activity by rapid membrane disruption at acidic pH, whereas its killing activity could be alleviated at normal pH, showing a significant pH response compared with LK. Importantly, this study found that the peptide LK-LE3 with the charge shielding in the N-terminal of LK displayed notably low cytotoxicity and more stability, demonstrating that the position of charge masking is extremely important for the improvement of peptide toxicity and stability. In short, our work opens a new avenue to design promising acid-activated ACPs as potential targeting agents for cancer treatment.

Effectiveness, safety and pharmacokinetics of Polo-like kinase 1 inhibitors in tumor therapy: A systematic review and meta-analysis

Objective

To provide a systematic review of existing meta-analysis on the efficacy, safety and pharmacokinetics of the novel Polo-like kinase-1 (Plk1) inhibitors in various tumor treatments, and assess the methodological quality and the strength of evidence of the included meta-analysis.

Methods

The Medline, PubMed, Embase, etc. were searched and updated on 30 June 2022. 22 eligible clinical trials involving a total of 1256 patients were included for analyses. Randomised controlled trials (RCTs) compared the efficacy or safety, or both of any Plk1 inhibitors with placebo (active or inert) in participants. To be included, studies had to be RCTs, quasi-RCTs, and nonrandomized comparative studies.

Results

A meta-analysis of two trials reported progression-free survival (PFS) of the overall population (effect size (ES), 1.01; 95% confidence intervals (CIs), 0.73-1.30, I² =0.0%, P<0.001) and overall survival (OS) of the overall population (ES, 0.91; 95% CIs, 0.31-1.50, I² =77.6%, P=0.003). 18 adverse events (AEs) reflected that the possibility of occurrence of AEs in the Plk1 inhibitors group was 1.28 times higher than in the control group (odds ratios (ORs), 1.28; 95% CIs,1.02-1.61). The results of meta-analysis showed that the incidence of AEs in the nervous system was the highest (ES, 0.202; 95% CIs, 0.161-0.244), followed by blood system (ES, 0.190; 95% CIs, 0.178-0.201) and digestive system (ES, 0.181; 95% CIs, 0.150-0.213). Rigosertib (ON 01910.Na) was associated with a decreased risk of AEs in digestive system (ES, 0.103; 95% CIs, 0.059-0.147), but BI 2536 and Volasertib (BI 6727) increased risk of AEs in blood system (ES, 0.399; 95% CIs, 0.294-0.504). Five eligible studies reported the pharmacokinetic parameters of the low dosage (100 mg) cohort and the high dosage (200 mg) cohort, and there was no statistical difference in the total plasma clearance, terminal half-life and apparent volume of distribution at steady state.

Conclusions

Plk1 inhibitors work better in improving OS and they are well tolerated, effective and safe in reducing the severity of illness while improving the quality of life, especially in patients with non-specific tumors, respiratory system tumors, musculoskeletal system tumors, and urinary system tumors. However, they fail to prolong the PFS. From the vertical whole level analysis, compared to other systems in the body, Plk1 inhibitors should be avoided as far as possible for the treatment of tumors related to the blood circulatory system, digestive system and nervous system, which were attributed to the intervention of Plk1 inhibitors associated with an increased risk of AEs in these systems. The toxicity caused by immunotherapy should be carefully considered. Conversely, a horizontal comparison of three different types of Plk1 inhibitors suggested that Rigosertib (ON 01910.Na) might be relatively suitable for the treatment of tumors associated with the digestive system, while Volasertib (BI 6727) might be even less suitable for the treatment of tumors associated with the blood circulation system. Additionally, in the dose selection of Plk1 inhibitors, the low dose of 100 mg should be preferred, and meanwhile, it can also ensure the pharmacokinetic efficacy that is indistinguishable from the high dose of 200 mg.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022343507.

Targeting Notch-Driven Cytokine Secretion: Novel Therapies for Triple Negative Breast Cancer

Compared with other breast cancer subtypes, triple negative breast cancer (TNBC) is an aggressive malignancy with a high recurrence rate and reduced overall survival. Immune checkpoint inhibition (ICI) has shown modest results in this subgroup, highlighting the need for improved targeted therapeutic options. Notch is a defining feature of TNBC and drives the expression of interleukin-1 beta (IL1β) and C-C motif chemokine ligand 2 (CCL2). These cytokines are involved in the recruitment of tumor-associated macrophages (TAMs) to the tumor, resulting in immune evasion and tumor progression. Targeting Notch, IL1β or CCL2 may reduce TAM recruitment and resistance to ICI, illuminating the potential of combination immunotherapy in TNBC.

Disruption of RBMS3 suppresses PD-L1 and enhances antitumor immune activities and therapeutic effects of auranofin against triple-negative breast cancer

Programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) interaction exerts a vital role in tumor-associated immune evasion. While strategies disrupting PD-1/PD-L1 axis have shown clinical benefits in various cancers, the limited response rate prompts us to investigate the complex mechanisms underlying the molecular regulation of PD-L1. Here, we identify the RNA binding protein RBMS3 as a crucial PD-L1 regulator in triple-negative breast cancer (TNBC). Correlation analysis shows that Rbms3 significantly correlates with immunosuppressive CD274, Rbms1, NT5E and ENTPD1. RBMS3 protein binds to CD274 mRNA specifically in TNBC cells to increase PD-L1 levels. Mechanistically, RBMS3 stabilizes CD274 mRNA by interacting with its 3'UTR, which represents as an intrinsic cancer cell mechanism for driving PL-D1 upregulation in TNBC. RBMS3 depletion not only destabilizes the mRNA stability and protein expression of PD-L1, but also suppresses the migratory abilities of TNBC MDA-MB-231 cells. Importantly, combination of RBMS3 ablation with auranofin (AUF), an FDA-approved thioredoxin reductase inhibitor, facilitates anti-tumor T-cell immunity in vivo and improves AUF-mediated anti-cancer effect. Taken together, our findings reveal RBMS3 as a key post-transcriptional regulator of PD-L1 and how they contribute to immune escape in TNBC, which could lead to novel combinatorial therapeutic strategies to enhance the efficacy of cancer immunotherapy.

Health-related quality of life in the phase III ASCENT trial of sacituzumab govitecan versus standard chemotherapy in metastatic triple-negative breast cancer

BACKGROUND

The antibody-drug conjugate sacituzumab govitecan (SG) prolongs progression-free survival and overall survival in patients with refractory/relapsed metastatic triple-negative breast cancer (mTNBC). Here, we investigated its effect on health-related quality of life (HRQoL).

METHODS

This analysis was based on the open-label phase III ASCENT trial (NCT02574455). Adults with refractory/relapsed mTNBC who had received ≥2 prior systemic therapies (≥1 in the metastatic setting) were randomised 1:1 to SG or treatment of physician's choice (TPC; capecitabine, eribulin, vinorelbine, or gemcitabine). HRQoL was assessed on day 1 of each treatment cycle using the EORTC QLQ-C30. Score changes from baseline were analysed using linear mixed-effect models for repeated measures. Stratified Cox regressions evaluated time to first clinically meaningful change of HRQoL.

RESULTS

The analysis population comprised 236 patients randomised to SG and 183 to TPC. For global health status (GHS)/QoL, physical functioning, fatigue, and pain, changes from baseline were superior for SG versus TPC. Compared with TPC, SG was inferior regarding changes from baseline for nausea/vomiting and diarrhoea but non-inferior for other QLQ-C30 domains. Median time to first clinically meaningful worsening was longer for SG than for TPC for physical functioning (22.1 versus 12.1 weeks, P < 0.001), role functioning (11.4 versus 7.1 weeks, P < 0.001), fatigue (7.7 versus 6.0 weeks, P < 0.05), and pain (21.6 versus 9.9 weeks, P < 0.001).

CONCLUSIONS

SG was generally associated with greater improvements and delayed worsening of HRQoL scores compared with TPC. This supports the favourable profile of SG as an mTNBC treatment.

Pamiparib in patients with locally advanced or metastatic HER2-negative breast cancer with germline BRCA mutations: a phase II study

PURPOSE

To evaluate the efficacy and safety of pamiparib in patients with locally advanced or metastatic human epidermal growth factor receptor 2-negative (HER2-) breast cancer, with deleterious or suspected deleterious germline BRCA1/2 mutations (gBRCA1/2 m).

METHODS

In this open-label, phase II, multicenter study in China (NCT03575065), patients with triple-negative breast cancer (TNBC cohort) or hormone receptor-positive (HR+)/HER2- breast cancer (HR+/HER2- cohort) and ≤ 2 prior lines of chemotherapy received pamiparib 60 mg orally twice daily in 28-day, continuous cycles. The primary endpoint was objective response rate (ORR; RECIST v1.1) by independent review committee.

RESULTS

In total, 88 patients were enrolled (TNBC cohort: 62; HR+/HER2- cohort: 26). Median age was 45.5 (range: 27-67) years, and 60 patients (68.2%) had received 1 or 2 prior lines of chemotherapy; 42 patients (47.7%) had previously received platinum chemotherapy. In the TNBC cohort, ORR was 38.2% (95% confidence interval [CI] 25.4-52.3) and median duration of response (DoR) was 7.0 months (95% CI 3.9-not estimable). In the HR+/HER2- cohort, ORR was 61.9% (95% CI 38.4-81.9) and median DoR was 7.5 months (95% CI 5.6-14.8). The most common treatment-emergent adverse events (TEAEs), treatment-related TEAEs, and ≥ Grade 3 TEAEs were hematologic (including anemia, decreased neutrophil count, and decreased white blood cell count). Overall, 64.8% of patients had TEAEs leading to dose reduction and 2.3% had TEAEs leading to treatment discontinuation.

CONCLUSION

Pamiparib showed encouraging efficacy and an acceptable safety profile in patients with locally advanced and metastatic HER2- breast cancer with gBRCA1/2 m.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03575065; July 2, 2018.

Immune-Checkpoint Inhibitors: A New Line of Attack in Triple-Negative Breast Cancer

Poor prognosis is a distinctive feature of triple-negative breast cancer (TNBC). Chemotherapy has long represented the main and unique treatment for patients with TNBC. Recently, immune checkpoint inhibitors (ICIs) were investigated in several clinical trials and were approved for clinical use in TNBC patients that express programmed cell death protein-1 (PD-1) in combination with chemotherapy in the first-line setting. ICIs are also being investigated in the neoadjuvant and adjuvant settings for TNBC. This chapter aims to discuss different ICIs used to treat all TNBC stages to date.

Pigment epithelium-derived factor downregulation in oestrogen receptor positive breast cancer bone metastases is associated with menopause

Pigment epithelium-derived factor (PEDF) has a critical role in bone development and anti-tumour function in breast cancer (BC). As the expression and role of PEDF in BC bone metastases is unknown, we aimed to characterise PEDF in primary and metastatic BC. Subcellular PEDF localisation was semi-quantitatively analysed via immunohistochemistry in patient-matched, archived formalin-fixed paraffin-embedded primary BC and liver, lung, and decalcified bone metastases specimens. PEDF localisation was evaluated in 23 metastatic BC patients diagnosed with ER+, human epidermal growth factor receptor-2 (HER2) negative BC or TNBC. Cytoplasmic (p = 0.019) and membrane (p = 0.048) PEDF was lower in bone metastases compared to primary ER+/HER2- BC. In contrast, nuclear PEDF scores were higher in metastases compared to primary TNBC (p = 0.027), and increased membrane PEDF in metastatic tissue had improved disease-free interval (p = 0.016). Nuclear PEDF was decreased in bone metastases compared to primary ER+//HER2- BC in post-menopausal patients (p = 0.029). These novel findings indicate PEDF plays a role in clinical BC metastasis. Significantly lower PEDF levels in the post-menopausal compared to pre-menopausal setting suggests future PEDF research may have greater clinical importance in the post-menopausal ER+/HER2- BC population.

Current Biological, Pathological and Clinical Landscape of HER2-Low Breast Cancer

HER2-low breast cancer (BC) is a newly defined subset of HER2-negative BC that has HER2 immunohistochemical (IHC) score of 1+ or score of 2+/in situ hybridization (ISH) negative phenotype. Recent clinical trials have demonstrated significant clinical benefits of novel HER2 directing antibody-drug conjugates (ADCs) in treating this group of tumors. Trastuzumab-deruxtecan (T-Dxd), a HER2-directing ADC was recently approved by the U.S. Food and Drug Administration as the first targeted therapy to treat HER2-low BC. However, HER2-low BC is still not well characterized clinically and pathologically. This review aims to update the current biological, pathological and clinical landscape of HER2-low BC based on the English literature published in the past two years and to propose the future directions on clinical management, pathology practice, and translational research in this subset of BC. We hope it would help better understand the tumor biology of HER2-low BC and the current efforts for identifying and treating this newly recognized targetable group of BC.

Natural Blockers of PD-1/PD-L1 Interaction for the Immunotherapy of Triple-Negative Breast Cancer-Brain Metastasis

The limited treatment options for triple-negative breast cancer with brain metastasis (TNBC-BM) have left the door of further drug development for these patients wide open. Although immunotherapy via monoclonal antibodies has shown some promising results in several cancers including TNBC, it cannot be considered the most effective treatment for brain metastasis. This is due to the protective role of the blood-brain barrier (BBB) which limits the entrance of most drugs, especially the bulky ones such as antibodies, to the brain. For a drug to traverse the BBB via passive diffusion, various physicochemical properties should be considered. Since natural medicine has been a key inspiration for the development of the majority of current medicines, in this paper, we review several naturally-derived molecules which have the potential for immunotherapy via blocking the interaction of programmed cell death protein-1 (PD-1) and its ligand, PD-L1. The mechanism of action, physicochemical properties and pharmacokinetics of these molecules and their theoretical potential to be used for the treatment of TNBC-BM are discussed.

Establishment and verification of a nomogram to predict tumor-specific mortality risk in triple-negative breast cancer: a competing risk model based on the SEER cohort study

Background

Triple-negative breast cancer (TNBC) is the subtype of breast cancer with the worst prognosis, and traditional survival analysis methods are biased when predicting mortality. To predict the risk of death in patients with triple-negative breast cancer more precisely, a competing risk model was developed.

Methods

The clinicopathological data of the TNBC patients from 2010 to 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. The data were assigned into a training set and testing set at a ratio of 7:3 in a randomized pattern. Univariate and multivariate competing risk models were applied to find the independent prognostic factors. A prediction nomogram for cancer-specific mortality (CSM) risk was constructed. The accuracy and discrimination of the nomogram were assessed using receiver operating characteristic (ROC) area under the curve (AUC), concordance index (C-index), and a calibration curve using the training and testing sets, respectively.

Results

A total of 28,430 TNBC patients were randomly grouped into the training set (n=19,900) and the testing set (n=8,530). The median time for follow-up was 59 [1-107] months. A total of 7,014 (24.67%) patients died, among whom 4,801 (68.45%) died from breast cancer and 2,213 (31.55%) due to non-breast cancer events. The independent risk factors were primary site of tumor, grade, tumor-node-metastasis (TNM) stage, T stage, approach of surgery, chemotherapy, axillary lymph node metastases, brain metastases, and liver metastases. The prediction nomogram was constructed by using the aforementioned variables. The 1-, 3-, and 5-year AUC of CSM were predicted to be 0.856, 0.81, and 0.782, respectively, in the training set, and 0.856, 0.81, and 0.782 in the testing set, respectively. The C-index of the nomogram was 0.801 and 0.799 in the training and testing sets, respectively. As confirmed by the validation and training calibration curves, the nomogram was consistent with the results.

Conclusions

We used competing risk models to identify risk factors for CSM and constructed a CSM risk prediction nomogram for TNBC patients, that may be utilized to predict CSM risk in TNBC patients clinically and assist in the creation of individualised clinical treatment options.

Eribulin Treatment for Patients with Metastatic Breast Cancer: The UK Experience - A Multicenter Retrospective Study

INTRODUCTION

This study examined real-world data from patients who received eribulin for metastatic breast cancer (MBC) collected from 14 hospitals across the UK.

METHODS

Anonymized data were collected retrospectively from patients with MBC who had received eribulin. The data included the hormone-receptor status, histological diagnosis, age, prior chemotherapy, response to eribulin, progression-free survival (PFS), and overall survival (OS).

RESULTS

Among 577 patients analyzed, the median age was 56 years, and most patients (73%) were estrogen-receptor positive. The median OS was 288 days (95% confidence interval [CI]: 261-315), and the PFS was 117 days (95% CI: 105-129). The median OS was higher among older patients (≥65 vs. <65 years: 325 days [95% CI: 264-385] vs. 285 days [95% CI: 252-317]; p = 0.028). The median OS was also higher in patients who received eribulin after fewer prior lines of chemotherapy (≤2 vs. >2 prior: 328 days [95% CI: 264-385] vs. 264 days [95% CI: 229-298]; p = 0.042).

DISCUSSION/CONCLUSION

These retrospective data suggest that eribulin can be successfully used in older patients with MBC. Eribulin treatment was more effective in earlier-line settings, which, while predictable, supports consideration of eribulin as a second-line treatment option.

PD-L1 Expression in Triple-negative Breast Cancer-a Comparative Study of 3 Different Antibodies

BACKGROUND

Assessment of programmed death protein-ligand 1 (PD-L1) in triple-negative breast cancer (TNBC) has entered daily practice to identify patients eligible for treatment with immune checkpoint inhibitors. However, different antibodies and different cut-offs for PD-L1 positivity are used, and the interchangeability of these methods is not clear. The aim of our study was to analyze whether different PD-L1 antibodies can be used interchangeably to identify TNBC patients as PD-L1 positive.

METHODS

A tissue microarray encompassing 147 TNBC cases was immunohistochemically analyzed using 3 different antibodies against PD-L1: SP142, SP263, and E1L3N. PD-L1 positivity was determined as ≥1% of positive tumor-associated immune cells. The staining patterns of the 3 antibodies were compared and correlated with clinicopathological data.

RESULTS

A total of 84 cases were evaluable for PD-L1 analysis with all 3 antibodies. PD-L1 was positive in 50/84 patients (59.5%) with SP263, in 44/84 (52.4%) with E1L3N, and in 29/84 (34.5%) with SP142. There was no statistical difference between the performance of SP263 and E1L3N, but both antibodies stained significantly more cases than the SP142 antibody.

CONCLUSIONS

Our results show that the 3 PD-L1 antibodies identify different TNBC patient subgroups as PD-L1 positive and, therefore cannot be used interchangeably. Additional studies are needed to further investigate the use and impact of different PD-L1 antibody clones for predictive selection of TNBC patients for treatment with immune checkpoint inhibitors.

Krüppel-like factor 7 influences translation and pathways involved in ribosomal biogenesis in breast cancer

Background

Ribosomal biogenesis and ribosomal proteins have attracted attention in the context of tumor biology in recent years. Instead of being mere translational machineries, ribosomes might play an active role in tumor initiation and progression. Despite its importance, regulation of ribosomal biogenesis is still not completely understood.

Methods

Using Gene Set Enrichment Analysis of RNA sequencing and proteomical mass spectrometry data in breast cancer cells expressing Krüppel-like factor 7 (KLF7), we identified processes altered by this transcription factor. In silico analyses of a cohort of breast cancer patients in The Cancer Genome Atlas confirmed our finding. We further verified the role of KLF7 the identified ribosomal processes in in vitro assays of mammary carcinoma cell lines and analyses of breast cancer patients’ tissue slices.

Results

We identified the transcription factor Krüppel-like factor 7 (KLF7) as a regulator of ribosomal biogenesis and translation in breast cancer cells and tissue. Highly significant overlapping processes related to ribosomal biogenesis were identified in proteomics and transcriptomics data and confirmed in patients’ breast cancer RNA Seq data. Further, nucleoli, the sites of ribosomal biogenesis, were morphologically altered and quantitatively increased in KLF7-expressing cells. Pre-rRNA processing was identified as one potential process affected by KLF7. In addition, an increase in global translation independent from proliferation and transcription was observed upon exogenous KLF7 expression in vitro. Importantly, in a cohort of breast cancer patients, KLF7-expression levels correlated with aggressiveness of the intrinsic breast cancer subtype and tumor grading. Moreover, KLF7 correlated with nucleolar characteristics in human breast tumor tissue, indicating a role for KLF7 in ribosomal biogenesis.

Conclusion

In mammary carcinoma, KLF7 is involved in ribosomal biogenesis. Alterations of ribosomal biogenesis has far reaching quantitative and qualitative implications for the proteome of the cancer cells. This might influence the aggressiveness of cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-022-01562-8.

An Overview of Clinical Development of Agents for Metastatic or Advanced Breast Cancer Without ERBB2 Amplification (HER2-Low)

Importance

Erb-b2 receptor tyrosine kinase 2 (ERBB2; formerly HER2 [human epidermal growth factor receptor 2]) is an important prognostic and predictive factor in breast cancer. Anti-ERBB2 therapies have improved outcomes in ERBB2-positive breast cancer. However, based on current definitions, tumors with low ERBB2 expression are included in the ERBB2-negative subtype, and therefore, are ineligible for anti-ERBB2 therapies; patients with ERBB2-low (immunohistochemistry [IHC] 1 positive [+] or IHC 2+/in situ hybridization [ISH] negative [-]) tumors account for up to approximately 50% of breast cancer cases. Although the prognostic role of ERBB2-low needs to be defined, ERBB2 offers a potential therapeutic target in these patients.

Observations

Most breast cancer tumors have some ERBB2 expression, with ERBB2-low being more common in hormone receptor-positive than in hormone receptor-negative breast cancer. Although an early clinical study failed to demonstrate benefit of adjuvant trastuzumab for ERBB2-low disease, several novel anti-ERBB2 therapies have shown efficacy in ERBB2-low breast cancer, including the antibody-drug conjugate trastuzumab deruxtecan in a phase 3 trial, and trastuzumab duocarmazine and the bispecific antibody zenocutuzumab in early-phase studies. Although reports are conflicting, some differences in biology and patient outcomes have been found between ERBB2-low and ERBB2 IHC-0 breast cancer. Currently, no established guidelines exist for scoring ERBB2-low expression in breast cancer because the focus has been on binary classification as ERBB2-positive or ERBB2-negative. Additional interpretive cutoffs may be needed to select patients for treatment with effective agents in ERBB2-low breast cancer, along with standardized laboratory quality assurance programs to ensure consistent patient identification for eligibility for ERBB2-low targeting agents.

Conclusions and Relevance

This review suggests that ERBB2-low may be a distinct, clinically relevant breast cancer entity warranting reassessment of traditional diagnostic and therapeutic paradigms. Ongoing clinical trials and further investigations may provide optimized strategies for diagnosing and treating ERBB2-low breast cancer, including reproducible, consistent definitions to identify patients in this diagnostic category and demonstration of benefits of emerging therapies.

A phase II study of TAS-117 in patients with advanced solid tumors harboring germline PTEN-inactivating mutations

PTEN acts as a potent tumor suppressor within the PI3K/AKT/mTOR pathway. Germline mutations in the PTEN gene are a hallmark of PTEN hamartoma tumor syndrome, which includes Cowden syndrome, where they appear to elevate lifetime risk of cancer. Targeted AKT directed therapy has been proposed as an effective approach in cancer patients having germline PTEN mutations. The mechanism of action, safety and dosing regimen for the novel allosteric AKT inhibitor TAS-117 have been explored in a phase I study in Japan in which activity was observed against certain tumor types. Here we describe the study protocol of an international, two-part phase II study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and antitumor activity of TAS-117 in patients with advanced solid tumors harboring germline PTEN-inactivating mutations.

A Systems Biology Approach to Investigate Kinase Signal Transduction Networks That Are Involved in Triple Negative Breast Cancer Resistance to Cisplatin

Triple negative breast cancer (TNBC) remains a therapeutic challenge due to the lack of targetable genetic alterations and the frequent development of resistance to the standard cisplatin-based chemotherapies. Here, we have taken a systems biology approach to investigate kinase signal transduction networks that are involved in TNBC resistance to cisplatin. Treating a panel of cisplatin-sensitive and cisplatin-resistant TNBC cell lines with a panel of kinase inhibitors allowed us to reconstruct two kinase signalling networks that characterise sensitive and resistant cells. The analysis of these networks suggested that the activation of the PI3K/AKT signalling pathway is critical for cisplatin resistance. Experimental validation of the computational model predictions confirmed that TNBC cell lines with activated PI3K/AKT signalling are sensitive to combinations of cisplatin and PI3K/AKT pathway inhibitors. Thus, our results reveal a new therapeutic approach that is based on identifying targeted therapies that synergise with conventional chemotherapies.

Sacituzumab govitecan as second-line treatment for metastatic triple-negative breast cancer-phase 3 ASCENT study subanalysis

Patients with triple-negative breast cancer (TNBC) who relapse early after (neo)adjuvant chemotherapy have more aggressive disease. In the ASCENT trial, sacituzumab govitecan (SG), an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38 via a hydrolyzable linker, improved outcomes over single-agent chemotherapy of physician's choice (TPC) in metastatic TNBC (mTNBC). Of 468 patients without known baseline brain metastases, 33/235 vs 32/233 patients (both 14%) in the SG vs TPC arms, respectively, received one line of therapy in the metastatic setting and experienced disease recurrence ≤12 months after (neo)adjuvant chemotherapy. SG prolonged progression-free survival (median 5.7 vs 1.5 months [HR, 0.41; 95% CI, 0.22-0.76]) and overall survival (median 10.9 vs 4.9 months [HR, 0.51; 95% CI, 0.28-0.91]) vs TPC, with a manageable safety profile in this subgroup consistent with the overall population. In this second-line setting, as with later-line therapy, SG improved survival over conventional chemotherapy for patients with mTNBC.