Metastatic Human Breast Cancer Research Articles

A systematic review of health-related quality of life outcomes in patients with advanced breast cancer treated with palbociclib.

Aim: To evaluate the impact of palbociclib treatment on health-related quality of life (HRQoL) in patients with hormone receptor-positive, human epidermal growth factor 2-negative advanced breast cancer (HR+/HER2- aBC) or metastatic breast cancer (mBC) in both the clinical and real-world setting. Materials & methods: A systematic literature review was conducted to identify clinical trials and real-world evidence studies up to June 2023 that reported HRQoL outcomes in patients with HR+/HER2- aBC or mBC treated with Palbociclib. Results: 15 unique studies reported across 35 records were identified. Of these, seven were randomized controlled trials (RCTs), three were single-arm clinical trials and five were real-world evidence (RWE) studies. HRQoL was generally found to be maintained in patients with HR+/HER2- aBC or mBC across RCTs, single-arm clinical trials and RWE studies. HRQoL measures across instruments, study types and line of therapy, were largely reported to be at least maintained if not improved from baseline among patients treated with palbociclib and were observed to be comparable or better in the palbociclib group versus monotherapy control arm in RCTs. Similar results were seen for treatment-related outcomes (e.g., sexual functioning, upset by hair loss, systemic therapy side effects etc.), and important individual patient outcomes, including pain, fatigue and physical functioning. Findings were also consistent across key clinical characteristics (visceral metastases, neutropenia), as well as patient populations often underrepresented in clinical trials (Asian patients, older adults). Conclusion: Overall, current evidence suggests that HRQoL is largely preserved with the addition of palbociclib to endocrine therapy in patients with HR+/HER2- aBC or mBC across study types and populations.

Mapping the transcriptional evolution of human metastatic breast cancer.

Many aspects of breast cancer metastasis remain poorly understood, despite its clinical importance. In this issue of the JCI, Winkler et al. have applied an elegant patient-derived xenograft (PDX) model to map the transcriptomes of single cells in matched primary tumors and lung metastases across 13 breast cancer PDX models. They identified distinct transcriptional changes associated with metastatic evolution in lowly and highly metastatic primary tumors. Furthermore, by classifying the "epithelial-mesenchymal plasticity" (EMP) state of single cells, they revealed that considerable EMP heterogeneity exists among primary and metastatic human breast cancer cells. However, the EMP profile of a tumor does not change substantially upon metastasis. These findings give an unprecedentedly detailed view into the transcriptional heterogeneity and evolution of metastatic human breast cancer.

Palbociclib: Randomized Studies and Real-world Evidence as the Basis for Therapeutic Planning in Metastatic Breast Cancer.

Endocrine-based combination therapy with an inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6 inhibitors) is currently the first-line therapy of choice for patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-), locally advanced or metastatic breast cancer (mBC). The efficacy and safety of the treatment with palbociclib, the first CDK4/6 inhibitor approved for this indication, have been confirmed in large randomized controlled clinical trials (RCTs) with strictly defined patient cohorts. Since then, many relevant questions about CDK4/6 inhibition with palbociclib for mBC have been investigated in RCTs and real-world studies. Based on this evidence, palbociclib is widely used in clinical practice since many years because of its efficacy and good tolerability. The aim of this review is to summarize findings from RCTs and RWE considering clinically relevant aspects such as safety, tolerability, quality of life and efficacy with a focus on specific questions and patient characteristics. A critical discussion and review of the overall evidence for endocrine-based therapy with the CDK4/6 inhibitor palbociclib can contribute to support therapy decisions in daily clinical practice.

Incidence and Prognostic Values in Human Epidermal Growth Factor Receptor 2-Low Expression Metastatic Breast Cancer in Southeast Asian Population: A 10-Year Retrospective Study.

Breast cancer progression varies across molecular subtypes, and treatment options for human epidermal growth factor receptor 2 (HER2)-low expression tumors are limited compared with those of HER2 overexpression tumors. Comprehensive information regarding the epidemiology and clinical outcomes of metastatic HER2-low expression breast cancer in a Southeast Asian population is lacking. This retrospective cohort study was performed to analyze data from patients with de novo advanced breast cancer, including HER2 expression, tumor stage, and metastatic pattern. Statistical analyses, including chi-square tests and survival analyses, were used to compare HER2-low expression and HER2-negative groups. Of the 491 patients, 21.2% had HER2-low expression, 30% had HER2 overexpression, and 50% had HER2-negative expression. Among the hormone receptor (HR)-positive patients, 34% had HER2-low expression; in the triple-negative patients, the HER2-low incidence was 20.6%. No significant differences in clinical characteristics between HER2-low and HER2-negative groups were observed, except for more HR-positive patients in the HER2-low group. HER2-low patients had a longer overall survival (OS) than HER2-negative patients (43 v 23 months; hazard ratio, 0.7; P < .001), especially in HR-positive patients. After adjusting for HR status, HER2-low patients maintained improved outcomes. HR-positive HER2-low patients showed nonsignificant OS gains compared with HR-positive HER2-negative patients, regardless of first-line chemotherapy or endocrine therapy. This study revealed the incidence and clinical outcomes of HER2-low expression in de novo advanced breast cancer, suggesting favorable outcomes, particularly in HR-positive breast cancer. These findings may inform personalized treatment strategies. Further research into the mechanisms and implications of HER2-low expression in breast cancer is required.

Current and Novel Treatment Options in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer.

Metastatic breast cancer (mBC) remains an incurable disease, and most patients will experience disease progression during their treatment course. Although endocrine therapy remains the mainstay of treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative mBC, significant progress has been and continues to be made in the treatment of this BC subtype. The discovery of molecular markers, mutations in key cellular pathways, and genomic signatures have led to the development of novel and targeted agents, such as antibody-drug conjugates, oral selective estrogen receptor downregulators, and inhibitors of the PI3K/AKT/mTOR pathway. This has resulted in significant improvements in the survival and quality of life of patients. With the increasing number of treatment options for patients, appropriate drug sequencing remains a challenge. Treatment discussions should involve patient-physician shared decision making, with consideration of genomic data, previous lines of therapy, side effect profiles, and clinical trial enrollment.

Fe-doped 45S5 bioactive glass compositions impair the metabolic activity and proliferation of metastatic human breast cancer cells in vitro

Many kinds of human tumors, including breast carcinomas, frequently metastasize to the bone, making it prone to pathologic fractures. Surgical management of bone metastases ranges from the resection of metastases to bone repair. Current surgical methods for the repair of bone defects include the use of polymethyl methacrylate (PMMA)-based bone cements. A promising alternative material are bioactive glass (BG) particles that in addition to providing physical stability can also induce bone regeneration. Moreover, BGs doped with Fe2O3may also have a negative impact on tumor cells. Here, we tested the hypothesis that BGs can affect metastatic human breast cancer cells. To this end, we assessed the effects of different BG compositions with and without Fe2O3on metastatic human MDA-MB-231 breast cancer cellsin vitro. We found that all BGs tested impaired the viability and proliferation of breast cancer cells in a concentration-dependent manner. The anti-proliferative effects inversely correlated with BG particle size, and were in general less pronounced in mesenchymal stromal cells (MSCs) that served as a control. Moreover, Fe2O3-doped BGs were more potent inhibitors of tumor cell proliferation and metabolic activity than Fe2O3-free BG. Our data therefore indicate that BGs can affect human breast cancer cells more strongly than MSCs, and suggest that the presence of Fe2O3can potentiate anti-proliferative and anti-metabolic effects of BGs. Fe2O3-doped BGs thus have the potential to be used for the surgical management of metastatic bone lesions, and may in addition to their regenerative properties also allow the local control of bone metastases.

Pyrotinib plus taxanes or vinorelbine for human epidermal growth factor receptor 2-positive metastatic breast cancer: A prospective study.

e13004 Background: Pyrotinib in combination with capecitabine is recommended as the second-line treatment for human epidermal growth factor 2 (HER2)-positive metastatic breast cancer (MBC) in China. The efficacy and safety of pyrotinib combined with non-capecitabine chemotherapy regimens remain unclear. Thus, we conducted this study to evaluate the efficacy and safety of pyrotinib combined with taxanes or vinorelbine in HER2-positive MBC. Methods: Patients with HER2-positive MBC were included to receive pyrotinib combined with taxanes or vinorelbine in Jiangsu Cancer Hospital. Patients received pyrotinib 400mg orally once daily plus taxanes (docetaxel 75-100 mg/m2 on day1, or nab-paclitaxel 125 mg/m2 on days 1 and 8, paclitaxel 80 mg/m2 on days 1 and 8, every 3 week) or vinorelbine 25 mg/m2 on days 1 and 8, every 3 weeks. 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), overall survival (OS) and safety. Results: Between Nov 20, 2018, and Jan 11, 2023, a total of 101 patients were assigned to pyrotinib plus taxanes group (n=83) and pyrotinib plus vinorelbine group (n=18). The median number of pyrotinib therapy lines was 2 (IQR 1-7), the first line accounted for 23.8%, the second line, and third line and above was 34.6%, 41.6%, respectively. As of May 24, 2023, the median PFS in the total was 11.5 months (95% confidence interval [CI], 8.8-15.7). The median PFS was significantly longer in the pyrotinib plus taxanes group than in the pyrotinib plus vinorelbine group, with median PFS being 12.2 months (95% CI, 9.2-18.6) and 8.4 months (95% CI, 5.5-13.7) (HR=2.2 [95% CI, 1.2-3.9]; P=0.005), respectively. The median PFS in the first-line, second-line, and third-line and above treatment was 28.6 (95% CI, 10.6-NA), 12.2 (95% CI, 8.5-16.3), and 8.3 months (95% CI, 6.3-14.5), respectively. The most common grade 3 or 4 adverse events were diarrhea (22.8%), leukopenia (19.5%), and neutropenia (18.2%). Conclusions: The median PFS of pyrotinib plus taxanes or vinorelbine, especially taxanes, was not inferior even superior to that of pyrotinib combined capecitabine. No increase treatment-related side effects was reported. Thus, the combination of pyrotinib and taxanes or vinorelbine regimen can be an option for HER2-positive MBC. Clinical trial information: ChiCTR2000041217.

A case of biopsy proven acute tubular injury from cyclin dependent kinase 4/6 inhibitor

Cyclin-dependent kinase (CDK) 4/6 inhibitors, combined with endocrine therapy, stand as one of the preferred first-line treatment regimens for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer. However, data regarding renal toxicities from CDK 4/6 inhibitors is conflicting. Some literature suggests a link to pseudo-acute kidney injury (AKI), while others indicate a potential intrinsic injury. These conflicting findings are compounded by the novelty of the treatment. We report a case of a 66-year-old woman with metastatic breast cancer who developed a true AKI on ribociclib, a CDK4/6 inhibitor. Upon evaluation, her urinalysis demonstrated proteinuria, and her serologic workup (including complements and free light chains) was within normal limits. Her Cystatin C-based eGFR was also found to be decreased. She ultimately underwent a kidney biopsy that demonstrated acute tubular injury (ATI). The etiology of her ATI was thought to be secondary to her CDK 4/6 inhibitor, as other factors causing ATI were ruled out. This case highlights that although much attention is put on CDK 4/6 inhibitors causing pseudo-AKI, it is imperative to ensure that patients are not experiencing true AKIs by assessing kidney function with alternative methods outside of creatinine, such as Cystatin C and exogenous filtration markers such as radionuclides, along with pursuing a renal biopsy when appropriate.

Comprehensive studies on the biological activities of human metastatic (MDA-MB-231) and non-metastatic (MCF-7) breast cancer cell lines, directly or combinedly treated using non-thermal plasma-based approaches

Progressive incidence and a pessimistic survival rate of breast cancer in women worldwide remains one of the most concerning topics. Progressing research indicates a potentially high effectiveness of use cold atmospheric plasma (CAP) systems. The undoubted advantage seems its simplicity in combination with other anti-cancer modalities. Following observed trend of studies, one inventory CAP system was applied to directly treat human breast cancer cell lines and culturing in two different Plasma Activated Media (PAM) for combined utilization. Proposed CAP treatments on MCF-10 A, MCF-7, and MDA-MB-231 cell lines were studied in terms of impact on cell viability by MTT assay. Disturbances in cell motility following direct and combined CAP application were assessed by scratch test. Finally, the induction of apoptosis and necrosis was verified with annexin V and propidium iodide staining. Reactive species generated during CAP treatment were determined based on optical emission spectrometry analysis along with colorimetric methods to qualitatively assess the NO2−, NO3−, H2O2, and total ROS with free radicals concentration. The most effective approach for CAP utilization was combined treatment, leading to significant disruption in cell viability, motility and mostly apoptosis induction in breast cancer cell lines. Determined CAP dose allows for mild outcome, showing insignificant harm for the non-cancerous MCF-10 A cell line, while the highly aggressive MDA-MB-231 cell line shows the highest sensitivity on proposed CAP treatment. Direct CAP treatment seems to drive the cells into the sensitive state in which the effectiveness of PAM is boosted. Observed anti-cancer response of CAP treatment was mostly triggered by RNS (mostly NO2− ions) and ROS along with free radicals (such as H2O2, OH•, O2-•, 1O2, HO2•). The combined application of one CAP source represent a promising alternative in the development of new and effective modalities for breast cancer treatment.

Abstract PO1-06-03: Efficacy of First-line Treatments for Hormone Receptor-positive, Human Epidermal Growth Factor Receptor 2-positive Metastatic Breast Cancer: A Systematic Literature Review and Network Meta-analysis Feasibility Assessment

Abstract Background: A comprehensive summary of clinical evidence for first-line (1L) treatments for hormone receptor-positive, human epidermal growth factor receptor 2-positive (HR+/HER2+) advanced or metastatic breast cancer (mBC) is needed to understand which treatments have been evaluated and the outcomes associated with different treatments. Understanding the available clinical evidence for HR+/HER2+ mBC 1L treatments can also inform the feasibility of network meta-analyses (NMAs) to estimate relative treatment effects where head-to-head trials are not available. The objective was to prepare a systematic summary of clinical trials of 1L treatments for HR+/HER2+ mBC and assess the feasibility of NMAs for key efficacy outcomes. Methods: A systematic literature review (SLR) was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical trials evaluating 1L treatments for adults with HR+/HER2+ mBC published between January 2000 and January 2023 were identified via predefined searches of databases (Embase, MEDLINE, Cochrane Library), relevant congress proceedings, and ClinicalTrials.gov (updating a previous SLR covering January 2000 to December 2020). Study design characteristics, patient characteristics, and efficacy outcomes were extracted from identified trials. An NMA feasibility assessment that considered network connectivity and cross-study heterogeneity was conducted for four efficacy outcomes of interest: progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and clinical benefit rate (CBR). Results: After screening, 37 records reporting on 23 unique studies (11 randomized controlled trials [RCTs] and 12 single-arm trials; 35 study arms in total) were selected. Included trials were mostly phase II or phase III multi-country studies that evaluated a HR+ or HER2+ population, with outcomes being reported for the subgroup of patients with the HR+/HER2+ subtype. Treatments evaluated included one or two anti-HER2 therapies (AHTs) + endocrine therapy (ET) (5/35 study arms), AHTs + chemotherapy (CT) (20/35), AHTs + ET + CT (2/35), AHTs alone (5/35), and ET alone (3/35). For HR+/HER2+ patients, PFS and OS were reported by 17/23 and 10/23 studies, respectively. Reported median PFS and OS ranged from 2.4-23.7 months and 23.9-66.7 months, respectively. Among the 11 included RCTs, hazard ratios and/or Kaplan-Meier curves, which were considered a requirement for NMAs for time to event outcomes, were reported for PFS and OS by 9 and 6 studies, respectively. Among these studies, reported median PFS and OS ranged from 2.4-19.2 months and 23.9-57.9 months, respectively. For HR+/HER2+ patients, ORR and CBR were reported by 13/23 and 6/23 studies, respectively. Assuming all CTs could be considered equivalent treatments and all ETs could be considered equivalent treatments, NMAs involving networks of 9, 6, 6, and 3 treatments were feasible for PFS, OS, ORR, and CBR, respectively. Some patient characteristics including time since mBC diagnosis and proportion with bone metastases were not reported consistently across trials. However, included studies were broadly comparable based on study design characteristics, outcome definitions and other reported patient characteristics such as age and Eastern Cooperative Oncology Group performance status. Conclusion: Clinical trials in 1L HR+/HER2+ mBC have evaluated various combinations of AHTs, CTs, and ETs, with most study arms being AHTs + CT. Although efficacy outcomes of interest were not consistently reported across trials, NMAs were found to be feasible for PFS, OS, ORR, and CBR based on available data. Citation Format: Priyanka Sharma, Chau Dang, Christopher Drudge, Amrita Debnath, Manvir Rai, Eric Gauthier, Edward Broughton. Efficacy of First-line Treatments for Hormone Receptor-positive, Human Epidermal Growth Factor Receptor 2-positive Metastatic Breast Cancer: A Systematic Literature Review and Network Meta-analysis Feasibility Assessment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-06-03.

Abstract PO4-04-12: A Phase 1b/2 study of palazestrant (OP-1250) in combination with ribociclib or alpelisib in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, advanced and/or metastatic breast cancer

Abstract Background: Endocrine therapy (ET) when administered with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors has improved outcomes in patients (pts) with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (BC) or metastatic breast cancer (MBC) and is the current standard of care for first-line treatment. Addition of the PIK3 inhibitor alpelisib to ET significantly improved progression-free survival in pts with PIK3CA-mutated, ER-positive, HER2-negative MBC, and alpelisib + fulvestrant is the standard of care for second or later-line treatment. Most pts will acquire resistance to ET, with mutations in ESR1 constituting the most common mechanism of resistance. Palazestrant (OP-1250) is a small molecule oral complete ER antagonist (CERAN) and selective ER degrader (SERD) that binds the ligand binding domain of ER and completely blocks ER-driven transcriptional activity in both wild-type (ESR1-wt) and mutant (ESR1-mut) forms of ER. In preclinical studies, palazestrant in combination with ribociclib demonstrated activity in both ESR1-wt and ESR1-mut xenograft models and showed efficacy in brain metastasis xenograft models. In a Phase 1/2 monotherapy study in pts with ER-positive, HER2-negative MBC, palazestrant was well tolerated with demonstrated antitumor efficacy and favorable pharmacokinetics (PK) supporting once a day (qd) dosing at the recommended Phase 2 dose (RP2D) of 120 mg. The aim of this study is to evaluate the safety, PK, and antitumor activity of palazestrant + ribociclib or alpelisib in pts with ER-positive, HER2-negative advanced BC or MBC. Methods: Eligible pts have evaluable ER-positive, HER2-negative advanced BC or MBC; ≤2 prior ETs (prior CDK4/6 inhibitors allowed); and ≤1 prior line of chemotherapy. In the alpelisib arm, pts must have a PIK3CA mutation in the tumor or ctDNA. Patients are administered oral palazestrant at escalating doses of 30, 60, and 120 mg qd in combination with the approved dose of oral ribociclib (600 mg qd; days 1–21 of 28-day cycle) or approved dose of oral alpelisib (300 mg qd) in a 3+3 design to identify the RP2D. The dose-expansion part will assess additional safety and PK parameters and the antitumor activity of palazestrant in combination with ribociclib or alpelisib (NCT05508906). Results: As of June 15, 2023, 10 pts have received 30 mg and 60 mg doses of palazestrant in combination with ribociclib (n=6) or alpelisib (n=4). No dose-limiting toxicities have been observed. After administration in the first two combination dose levels of 30 and 60 mg, palazestrant exposure was consistent with monotherapy administration; exposure data show no drug–drug interactions (DDI) when compared to published exposure parameters. Most reported treatment-emergent adverse events (TEAEs) were grade 1 or 2 and consistent with the known safety profiles of all 3 drugs. In the ribociclib arm, the TEAEs occurring in ≥2 pts included grade 1 nausea (n=4), grade 1 constipation (n=2), and neutropenia (grade 2, n=1; grade 3, n=3). For the 3 pts in the 30 mg palazestrant + alpelisib cohort, the only TEAE occurring in ≥2 pts was grade 1 diarrhea. One pt had grade 1 hyperglycemia. Conclusions: In this ongoing study, palazestrant in combination with ribociclib or alpelisib was well tolerated, and enrollment to the palazestrant 120 mg dose with ribociclib or alpelisib is ongoing. No new safety signals were observed for the 3 drugs, and no clinically significant DDIs were observed between palazestrant and ribociclib or alpelisib at the doses evaluated. Exposure of each drug was consistent with observed monotherapy exposure levels. Updated data will be presented. Citation Format: Virginia Borges, Carlos Alemany, Nancy Lin, Sara Nunnery, Cynthia Ma, Margaret Tonda, Morena Shaw, Arlene Chan. A Phase 1b/2 study of palazestrant (OP-1250) in combination with ribociclib or alpelisib in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, advanced and/or metastatic breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-04-12.

Abstract PO1-04-13: CARDIAC-STAR: Prevalence of Cardiovascular Comorbidities in Hormone Receptor Positive Human Epidermal Growth Factor Negative metaStatic breasT cAnceR

Abstract BACKGROUND: Baseline cardiovascular (CV) comorbidities can impact treatment decisions for patients (pts) with metastatic breast cancer (mBC). There is limited data on the prevalence of CV comorbidities at the time of hormone receptor positive human epidermal growth factor negative (HR+/HER2-) mBC diagnosis. The primary objective of this study is to describe the prevalence of pre-existing CV comorbidities in women and men with newly diagnosed HR+/HER2- mBC. A secondary objective is to describe the first documented cancer treatment for patients with or without CV comorbidities. METHODS: Women and men ≥18 years of age with newly diagnosed HR+/HER2- mBC from 01/2016 to 12/2021 were included in this retrospective, observational study using the Merative™ Marketscan® Commercial and Medicare Databases which is nationally representative. Evidence of mBC was defined as having two or more claims containing one or more diagnosis code for BC at least 30 days apart and at least two secondary malignancy diagnosis codes. Previously published claims-based algorithms were used to identify the HR+/HER2- molecular subtype. The index date is defined as the date of first mBC diagnosis. Patients had a 1-year pre-index period for observation of CV comorbidities and a 6-month post-index period for first documented cancer treatmen RESULTS: We identified 5,452 pts with HR+/HER2- mBC, 99% of whom were female, with a median age of 58 years (yrs) (IQR 13), and 83% having a health plan from an employer; i.e., are still employed. At mBC diagnosis, 3,335 pts (61.2%) had at least one pre-existing CV comorbidity (see Table). The most reported CV comorbidities were hypertension (50.7%), hyperlipidemia (33.7%), and diabetes (19.2%). The median age of pts with or without a CV comorbidity was 61 and 52 yrs, respectively; 16.2% with CV comorbidities were ≥75 yrs. Additional data, including first documented treatment, will be presented at the meeting. CONCLUSIONS: The prevalence of CV comorbidities in pts with HR+/HER2- mBC is often underrecognized. In this analysis, more than half of pts had at least one CV comorbidity by mBC diagnosis. CV comorbidities may impact treatment decisions in the HR+/HER2- mBC population, particularly in older pts. Table Citation Format: Susan Dent, Avirup Guha, Heather Moore, Rachael McCaleb, Irene Arias, Stella Stergiopoulos, Benjamin Li, Doris Makari, Michael Fradley. CARDIAC-STAR: Prevalence of Cardiovascular Comorbidities in Hormone Receptor Positive Human Epidermal Growth Factor Negative metaStatic breasT cAnceR [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-04-13.

Abstract PS15-04: A Phase 1b/2 study of palazestrant (OP-1250), an oral complete estrogen receptor antagonist (CERAN) and selective ER degrader (SERD), with palbociclib in ER-positive, HER2-negative, advanced or metastatic breast cancer patients

Abstract Background: Palazestrant (OP-1250) is a small molecule oral complete estrogen receptor (ER) antagonist (CERAN) and selective ER degrader (SERD) that binds the ligand binding domain of ER and completely blocks ER-driven transcriptional activity in both wild-type (ESR1-wt) and mutant (ESR1-mut) forms of ER. In preclinical studies, palazestrant demonstrated improved tumor growth inhibition and shrinkage when combined with a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. In a Phase 1/2 monotherapy clinical study in patients with ER-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer, palazestrant was well tolerated with demonstrated antitumor efficacy and favorable pharmacokinetics (PK) supporting once a day (qd) dosing at the recommended Phase 2 dose of 120 mg. In this study, pts received palazestrant at escalating doses of 30, 60, 90, and 120 mg qd in combination with palbociclib (125 mg qd) and no dose-limiting toxicities were observed. Palazestrant did not affect palbociclib PK and no drug–drug interactions (DDIs) occurred. Here we report updates on safety, efficacy, and PK from the ongoing study of palazestrant in combination with palbociclib. Methods: Patients with advanced or metastatic breast cancer with progression on or after ≤1 line of endocrine therapy (prior CDK4/6 inhibitor therapy and ≤1 chemotherapy allowed) were enrolled to receive oral palazestrant 120 mg qd with oral palbociclib 125 mg qd for 21 of 28 days (NCT0526610). Results: As of May 12, 2023, 33 patients have been treated with palazestrant in combination with palbociclib; 12 pts were dosed in the dose-escalation phase and 21 patients were dosed in the dose-expansion phase of the study. Twenty-two patients (67%) received prior CDK4/6 inhibitor therapy; 15 patients received prior palbociclib. Thirteen of 25 patients (52%) with available baseline ctDNA had an ESR1 mutation. The most common (≥20%) treatment-emergent adverse events (TEAEs) were neutropenia, nausea, vomiting, constipation, and diarrhea. Most of these events were grade 1 or 2. The most common grade 3 or 4 related AE was neutropenia (18/33 [55%] were grade 3; 3/33 [9%] were grade 4). The steady-state exposure of palazestrant when dosed with 125 mg palbociclib was consistent with the monotherapy study. Palbociclib exposure at steady-state was comparable to published monotherapy data when combined with palazestrant at all dose levels tested. As of the data cut-off, there were 4 partial responses (2 confirmed) out of 19 response-evaluable patients, with a clinical benefit rate (CBR) of 42% (8/19) across all patients and 67% (6/9) in patients with ESR1 mutations. Conclusions: Palazestrant and palbociclib dosed in combination were well tolerated with a safety profile consistent with the individual profiles of each drug as monotherapy, and there were no DDIs. Tumor responses and clinical benefit were observed in this population of patients, including those who received prior CDK4/6 inhibitors. Expanding on our previous report, these data provide the rationale to continue advancing the clinical development of palazestrant with the approved dose of palbociclib. Updated data will be presented. Citation Format: Arlene Chan, Daphne Day, Phuong Dinh, Michael Slancar, Janine Lombard, Vinod Ganju, Nicole McCarthy, Rosalind Wilson, Demiana Faltaos, Gurpreet Mathauda-Sahota, Caitlin Murphy. A Phase 1b/2 study of palazestrant (OP-1250), an oral complete estrogen receptor antagonist (CERAN) and selective ER degrader (SERD), with palbociclib in ER-positive, HER2-negative, advanced or metastatic breast cancer patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS15-04.

Cost of disease progression among US patients with human epidermal growth factor receptor 2-positive metastatic breast cancer.

Aim: The objectives were to investigate the differences in per patient per month (PPPM) healthcare resource utilization (HCRU) and costs among commercially insured and Medicare Advantage patients with human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer (mBC) who experience disease progression in 12months compared with those who don't investigate the impact of progression timing on cumulative healthcare costs. Patients & methods: This claims-based study included patients diagnosed with mBC between 1January 2013 and 30April 2020 and received HER2-targeted therapy. Patients were categorized as progressed or nonprogressed. For objective one, monthly HCRU and costs were assessed for up to two lines of therapy (LOTs). Data were summarized descriptively and compared using a generalized linear model (GLM). For objective two, patients with at least 6 months of follow-up were assessed and cumulative healthcare costs were estimated in the 3 years following the start of LOT1 or LOT2 using a GLM and Kaplan-Meier weighting. Results: Among the 4113 patients in the study sample, 3406 had at least 12 months of follow-up (or less if due to death). Compared with nonprogressed patients, progressed patients had higher mean PPPM healthcare costs (LOT1: $22,014 vs $18,372, p<0.001; LOT2: $19,643 vs $16,863, p=0.001), and HCRU, including number of emergency room visits and inpatient stays (both p<0.001) in the 12 months following LOT start. Progressed patients had higher 3-year mean cumulative healthcare costs than nonprogressed patients following LOT1 and LOT2 and this difference was greater for patients who progressed earlier. Conclusion: Disease progression was associated with significant increases in HCRU and costs. Delays in progression were associated with lower cumulative healthcare costs. Earlier use of more clinically effective treatments to delay progression may reduce the economic burden among these patients.

Efficacy and safety of Trastuzumab Emtansine in treating human epidermal growth factor receptor 2-positive metastatic breast cancer in Chinese population: a real-world multicenter study.

Trastuzumab emtansine (T-DM1) has been approved worldwide for treating metastatic breast cancer (mBC) in patients who have received first-line therapy, shown disease progression, and are human epidermal growth factor receptor 2 (HER2)-positive. T-DM1 received approval in China to treat early-stage breast cancer (BC) in 2020 and for mBC in 2021. In March 2023, T-DM1 was included in medical insurance coverage, significantly expanding the eligible population. This post-marketing observational study aimed to assess the safety and effectiveness of T-DM1 in real-world clinical practice in China. This study enrolled 31 individuals with HER2-positive early-stage BC and 70 individuals with HER2-positive advanced BC from 8 study centers in Shandong Province, China. The T-DM1 dosage was 3.6 mg/kg injected intravenously every 3 weeks until the disease advanced or the drug toxicity became uncontrollable, whichever occurred earlier. Additionally, efficacy and safety information on T-DM1 were collected. During the 7-month follow-up period, no recurrence or metastases were observed in patients who had early-stage BC. The disease control rate was 31.43% (22/70) in patients with advanced BC. The most common adverse effect of T-DM1 was thrombocytopenia, with an incidence of 69.31% (70/101), and the probability of Grade ≥ 3 thrombocytopenia was 11.88% (12/101). This real-world study demonstrated that T-DM1 had good efficacy and was well tolerated by both HER2-positive early-stage BC and mBC patients.

The Marine Alga Sargassum horneri Is a Functional Food with High Bioactivity

Functional food factors can play a preventive and therapeutic role in several human diseases. The marine alga Sargassum horneri (S. horneri) has restorative effects in several types of metabolic disorders, including osteoporosis, diabetes, inflammatory conditions, and cancer cell growth. Osteoporosis is widely recognized as a major public health problem. Bone loss associated with ageing and diabetic states was prevented through the intake of bioactive compounds from S. horneri water extract in vivo by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption in vitro. The intake of S. horneri water extract was found to have preventive effects on diabetic findings with an increase in serum glucose and lipid components. Furthermore, the S. horneri component has been shown to suppress adipogenesis from rat bone marrow cells and inflammatory conditions in vitro. Notably, the growth of bone metastatic human breast cancer MDA-MB-231 cells, which induce bone loss with osteolytic effects, was suppressed through culturing with the S. horneri water extract component in vitro. The S. horneri component, which has a molecular weight of less than 1000, was found to suppress the activation of NF-κB signaling by tumor necrosis factor-α, a cytokine associated with inflammation, in osteoblastic cells and macrophage RAW264.7 cells in vitro, suggesting a molecular mechanism. The bioactive component of S. horneri may play a multifunctional role in the prevention and treatment of metabolic disorders. This review outlines the advanced knowledge of the biological activity of the aqueous extract components of S. horneri and discusses the development of health supplements using this material.

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

BackgroundApproximately 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 MethodsWe 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. ResultsEfficacy 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. ConclusionPyrotinib-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.

Iron oxide nanoparticles synthesized using Mentha spicata extract and evaluation of its antibacterial, cytotoxicity and antimigratory potential on highly metastatic human breast cells

Iron oxide nanoparticles (Fe2O3 NPs) were synthesized utilizing Mentha spicata sourced from Cyprus as a stabilizing agent. The study delved into assessing the antimicrobial, cytotoxic, anti-proliferative, and anti-migratory potential of Fe2O3 NPs through disc diffusion, trypan blue, and 3-[4, 5-dimethylthiazol-2-yl]−2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Characterization of the synthesized Fe2O3 NPs was conducted using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), UV–vis spectroscopy (UV–vis), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX). The FTIR, XRD, and SEM-EDX spectra confirmed the successful formation of Fe2O3 NPs. The analysis of UV–vis spectra indicates an absorption peak at 302 nm, thereby confirming both the successful synthesis and remarkable stability of the nanoparticles. The nanoparticles exhibited uniform spherical morphology and contained Fe, O, and N, indicating the synthesis of Fe2O3 NPs. Additionally, the Fe2O3 NPs formed through biosynthesis demonstrated antimicrobial capabilities against Escherichia coli and Bacillus cereus. The significant anti-migratory potential on MDA-MB 231 human breast cancer cells was observed with lower concentrations of the biosynthesized Fe2O3 NPs, and higher concentrations revealed cytotoxic effects on the cells with an IC50 of 95.7 μg/ml. Stable Fe2O3 NPs were synthesized using Mentha spicata aqueous extract, and it revealed antimicrobial activity on E. coli and B. cereus, cytotoxic, anti-proliferative and anti-migratory effect on highly metastatic human breast cancer cell lines.

Therapy for Hormone Receptor-Positive, Human Epidermal Growth Receptor 2-Negative Metastatic Breast Cancer Following Treatment Progression via CDK4/6 Inhibitors: A Literature Review.

Endocrine therapy (ET) with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) is currently the first-line standard treatment for most patients with hormone receptor-positive (HR+) and human epidermal growth receptor 2-negative (HER2-) metastatic or advanced breast cancer. However, the majority of tumors response to and eventually develop resistance to CDK4/6is. The mechanisms of resistance are poorly understood, and the optimal postprogression treatment regimens and their sequences continue to evolve in the rapidly changing treatment landscape. In this review, we generally summarize the mechanisms of resistance to CDK4/6is and ET, and describe the findings from clinical trials using small molecule inhibitors, antibody-drug conjugates and immunotherapy, providing insights into how these novel strategies may reverse treatment resistance, and discussing how some have not translated into clinical benefit. Finally, we provide rational treatment strategies based on the current emerging evidence.

Abstract 3157: The crosstalk between STAT3 and p53/ERK signaling regulates brain metastasis

Abstract Brain metastasis (BM) affects approximately 10% of cancer patients with metastatic disease, representing a major cause of morbidity and mortality. BM is a complex multi-step process involving various immune checkpoint proteins. Mitogen-activated protein kinase (MAPK), particularly extracellular signal-regulated kinases 1/2 (ERK1/2), and signal transducer and activator of transcription 3 (STAT3) are implicated in tumorigenesis and are critical upstream regulators of Programmed Death Ligand 1 (PD-L1) expression, a common immunotherapy target. Tumor suppressor p53 is shown to regulate STAT3 and ERK1/2 signaling, which are dysregulated in various malignancies. We hypothesize that p53 along with STAT3 and ERK1/2 play a critical role in the initiation and maintenance of BM. Twenty-six BM tumors with various primary sites of origin were used following IRB guidelines. pSTAT3Tyr705, pERK1/2Thr202/Tyr204, mutant p53 (p53mt), and PD-L1 expression was determined by immunohistochemistry. Gene expression analysis of BM was performed on a cDNA microarray. Human brain metastatic breast cancer cells (MDA-MB-231) were treated with STAT3 inhibitor (NSC74859) or MAPK inhibitor (U0126) in regular or astrocytic media to determine cell proliferation and migration by MTT assay and scratch-wound, respectively. ERK1/2 signaling pathway status was determined by Western blotting. Results demonstrated: 1) pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 were expressed profusely at tumor margins, while p53mt was uniformly expressed throughout. 81% of BM expressed p53mt while 86% and 63% expressed pERK1/2Thr202/Tyr204 and pSTAT3Tyr705, respectively. Venn analysis displayed significant overlap between expression, with 62% overlap between p53mt and pERK1/2Thr202/Tyr204 and a 50% overlap between both pSTAT3Tyr705 and pERK1/2Thr202/Tyr204 with p53mt. Expression of PD-L1 was seen in a majority of BM tumors. 2) Gene expression analysis demonstrated alterations in 32 STAT3- and MAPK-associated genes; these included upregulation of stathmin-1 and stathmin-like 3, which control microtubule dynamics in STAT3-related cell migration, and changes in cytokine-related genes, suggesting altered immune responses. 3) Cell proliferation showed augmented growth in astrocytic media (p≤0.05) and was significantly decreased following treatment with NSC74850 or U0126 (p≤0.01). While migration showed a trend towards significance in reduction following NSC74859 (p=0.08), migration stagnated following U0126 treatment in astrocytic media (p≤0.01). 4) pERK1/2Thr202/Tyr204 expression was reduced following U0126 or NSC74859 treatment. These findings suggest activation of STAT3 and ERK1/2 promote BM and suppression of these pathways may lead to a reduction in cell viability and motility. Therefore, this provides compelling evidence for the use of STAT3 and ERK1/2 along with p53 as potential targets for immunotherapy in brain metastatic disease. Citation Format: Sabrina L. Zeller, Eris Spirollari, John V. Wainwright, Simon J. Hanft, Chirag D. Gandhi, Meena Jhanwar-Uniyal. The crosstalk between STAT3 and p53/ERK signaling regulates brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3157.