Metronomic chemotherapy (mCHT) in metastatic triple-negative breast cancer (TNBC) patients: results of the VICTOR-6 study

Current approaches to the pharmacological management of metastatic breast cancer in older women

INTRODUCTION

A substantial majority of patients diagnosed with metastatic breast cancer consists of individuals 65-year-old or above. Emerging treatment approaches, which utilize genomics-guided therapy and innovative biomarkers, are currently in development. Given the numerous choices in the metastatic context, it is necessary to adopt a personalized approach to decision-making for these patients.

AREAS COVERED

The authors provide a comprehensive analysis of the existing literature on the use of systemic anticancer treatments in older women, specifically those aged 65 and above, who have metastatic breast cancer, focusing on the reported effectiveness and adverse effects of these treatments in this population.

EXPERT OPINION

The evidence to treat older patients with metastatic breast cancer primarily relies on subgroup analyses, whose interpretation should be approached with caution. In several clinical trials subgroup analysis, it has been observed that this population seem to have comparable benefits and toxicities to younger patients, but real-world data have showed older women exhibit worse rates of survival compared to younger women. Multiple factors are likely involved in this, but we postulate this is related to lower rates of guideline concordant, and factors such as comorbidity, lack of social supports, malnutrition, and geriatric factors like frailty and/or vulnerability. This underscores the importance of a broader assessment for patients with a geriatric perspective and involvement of multi-disciplinary team.

Phase II randomized trial comparing metronomic anthracycline-containing chemotherapy versus standard schedule in untreated HER2 negative advanced breast cancer: activity and quality of life results of the GOIM 21003 trial

BACKGROUND

Optimizing chemotherapy to achieve disease and symptoms control is a noteworthy purpose in advanced breast cancer (ABC). We reported the activity and quality of life of a phase II study, comparing metronomic regimen with standard schedule as first line chemotherapy for ABC.

METHODS

Patients with HER2 negative ABC were randomized to non-pegylated liposomal doxorubicin (NPLD, 60 mg/m2 every 3 weeks) and cyclophosphamide (CTX, 600 mg/m2 every 3 weeks) (Arm A) or NPLD (20 mg/m2 day, on day 1, 8 and 15 every 4 weeks) and metronomic daily oral CTX 50 mg (ARM B). Primary end-points were overall response rate (ORR) and quality of life, secondary progression-free survival (PFS), overall survival (OS) and toxicity.

RESULTS

From August 2012 to December 2017, 121 patients were enrolled, 105 evaluable. Median follow-up was 21.3 months. Most patients had hormone receptor positive. ORR was 43 % in arm A and 50 % in arm B. Median PFS was 8.9 months in arm A and 6,4 months in arm B. There was no difference in OS. Total score was not clinically different between the two arms. Grade 4 neutropenia was observed in 12 patients and 16 patients respectively; alopecia G2 in 41 % (77 %) vs 14 (27 %) in arm A and in arm B respectively. One cardiac toxicity was observed (arm A).

CONCLUSIONS

First line metronomic chemotherapy for HER2 negative ABC had similar clinical activity and quite better tolerability than standard schedule and could be considered a further treatment option when chemotherapy is indicated.

Single-agent metronomic versus weekly oral vinorelbine as first-line chemotherapy in patients with HR-positive/HER2-negative advanced breast cancer: The randomized Tempo Breast study

INTRODUCTION

Single-agent oral vinorelbine is a standard of care for hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) that has progressed on endocrine therapy. Metronomic administration may offer a better balance of efficacy and safety than standard regimens, but data from previous trials are scarce.

METHODS

In this open-label, multicenter, phase II trial, patients were randomized to oral vinorelbine administered on a metronomic (50 mg three times weekly) or weekly (60 mg/m2 in cycle 1, increasing to 80 mg/m2 if well tolerated) schedule. Treatment was continued until disease progression or intolerance. The primary endpoint was disease control rate (DCR, the proportion of patients with a best overall confirmed response of CR, PR, or stable disease lasting 6 months or more).

RESULTS

One-hundred sixty-three patients were randomized and treated. The DCR was 63.4% (95% confidence interval [CI]: 52.0-73.8) with metronomic vinorelbine and 72.8% (95% CI: 61.8-82.1) with weekly vinorelbine. Weekly vinorelbine was also associated with longer progression-free survival (5.6 vs 4.0 months) and overall survival (26.7 vs 22.3 months) than metronomic vinorelbine, but was associated with more adverse events.

CONCLUSIONS

In this randomized phase II trial, single-agent metronomic oral vinorelbine was effective and well tolerated as first-line chemotherapy for patients with HR-positive/HER2-negative ABC. Formal comparisons are not done in this phase II study and one can simply observe that confidence intervals of all endpoints overlap. When deciding for a chemotherapy after failure of endocrine therapy and CDK 4/6 inhibitors, oral vinorelbine might be an option to be given with either schedule.

CLINICAL TRIAL REGISTRATION NUMBER

EudraCT 2014-003860-19.

Differential Expression of NOTCH-1 and Its Molecular Targets in Response to Metronomic Followed by Conventional Therapy in a Patient with Advanced Triple-Negative Breast Cancer

A group of 27 patients diagnosed with metastatic triple-negative breast cancer (mTNBC) was randomly distributed into two groups and underwent different lines of metronomic treatment (mCHT). The former group (N 14) received first-line mCHT and showed a higher overall survival rate than the second group (N 13), which underwent second-line mCHT. Analysis of one patient still alive from the first group, diagnosed with mTNBC in 2019, showed a complete metabolic response (CMR) after a composite approach implicating first-line mCHT followed by second-line epirubicin and third-line nab-paclitaxel, and was chosen for subsequent molecular characterization. We found altered expression in the cancer stemness-associated gene NOTCH-1 and its corresponding protein. Additionally, we found changes in the expression of oncogenes, such as MYC and AKT, along with their respective proteins. Overall, our data suggest that a first-line treatment with mCHT followed by MTD might be effective by negatively regulating stemness traits usually associated with the emergence of drug resistance.

Key Considerations for the Treatment of Advanced Breast Cancer in Older Adults: An Expert Consensus of the Canadian Treatment Landscape

The prevalence of breast cancer amongst older adults in Canada is increasing. This patient population faces unique challenges in the management of breast cancer, as older adults often have distinct biological, psychosocial, and treatment-related considerations. This paper presents an expert consensus of the Canadian treatment landscape, focusing on key considerations for optimizing selection of systemic therapy for advanced breast cancer in older adults. This paper aims to provide evidence-based recommendations and practical guidance for healthcare professionals involved in the care of older adults with breast cancer. By recognizing and addressing the specific needs of older adults, healthcare providers can optimize treatment outcomes and improve the overall quality of care for this population.

A phase II study of a doublet metronomic chemotherapy regimen consisting of oral vinorelbine and capecitabine in Chinese women with HER2-negative metastatic breast cancer

BACKGROUND

This single-arm prospective phase II trial was performed to assess the efficacy and safety of the dual oral metronomic vinorelbine and capecitabine (mNC) regimen in women with HER2-negative metastatic breast cancer (MBC) in China.

METHODS

The mNC regimen was administered to the enrolled cases, including oral vinorelbine (VNR) 40 mg three times weekly (on days 1, 3 and 5 every week) and capecitabine (CAP) 500 mg three times a day, until disease progression or intolerable toxicity. The primary endpoint was the 1-year progression-free survival (PFS) rate. Secondary endpoints included objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR) and treatment-related adverse events (TRAEs). Stratified factors included treatment lines and hormone receptor (HR) status.

RESULTS

Between June 2018 and March 2023, 29 patients were enrolled into the study. The median follow-up time was 25.4 months (range, 2.0-53.8). In the entire group, the 1-year PFS rate was 54.1%. ORR, DCR and CBR were 31.0%, 96.6% and 62.1%, respectively. The mPFS was 12.5 months (range, 1.1-28.1). Subgroup analysis revealed that ORRs were 29.4% and 33.3% in first- and ≥second-line chemotherapy, respectively. ORRs were 29.2% (7/24) and 40.0% (2/5) for HR-positive MBC and metastatic triple-negative breast cancer (mTNBC), respectively. Grade 3/4 TRAEs were neutropenia (10.3%) and nausea/vomiting (6.9%).

CONCLUSIONS

The dual oral mNC regimen showed very good safety features and improved compliance without loss of efficacy in both first- and second-line treatments. The regimen also reached an excellent ORR in the mTNBC subgroup.

Final results of the real-life observational VICTOR-6 study on metronomic chemotherapy in elderly metastatic breast cancer (MBC) patients

Nowadays, treatment of metastatic breast cancer (MBC) has been enriched with novel therapeutical strategies. Metronomic chemotherapy (mCHT) is a continuous and frequent administration of chemotherapy at a lower dose and so whit less toxicity. Thus, this strategy could be attractive for elderly MBC patients. Aim of this analysis is to provide insights into mCHT's activity in a real-life setting of elderly MBC patients. Data of patients ≥ 75 years old included in VICTOR-6 study were analyzed. VICTOR-6 is a multicentre, Italian, retrospective study, which collected data on mCHT in MBC patients treated between 2011 and 2016. A total of 112 patients were included. At the beginning of mCHT, median age was 81 years (75-98) and in 33% of the patients mCHT was the first line choice. Overall Response Rate (ORR) and Disease Control Rate (DCR) were 27.9% and 79.3%, respectively. Median PFS ranged between 7.6 and 9.1 months, OS between 14.1 and 18.5 months. The most relevant toxicity was the hematological one (24.1%); severe toxicity (grade 3-4) ranged from 0.9% for skin toxicity up to 8% for hematologic one. This is a large study about mCHT in elderly MBC patients, providing insights to be further investigated in this subgroup of frail patients.

Real-World Experience of Metronomic Chemotherapy in Metastatic Breast Cancer: Results of a Retrospective Unicenter Study

INTRODUCTION

Metronomic chemotherapy (MCT) is increasingly used in oncology due to its favorable therapeutic index. There is still a lack of evidence for MCT in metastatic breast cancer (MBC). In this retrospective unicenter study, we demonstrated real-word data on MCT in MBC.

METHODS

MBC patients who received metronomic oral cyclophosphamide (CTX) (50 mg daily) and methotrexate (MTX) (2.5 mg every other day), CTX and capecitabine (CAPE) (500 mg thrice daily), CTX, or vinorelbine (VRL) (30 mg daily) alone for at least 4 weeks between 2009 and 2021 were included. The primary endpoint was disease control rate (DCR) ≥24 weeks. Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Patient characteristics and therapy response were analyzed using χ2 test. For survival analyses, Kaplan-Meier estimator and log-rank test were used.

RESULTS

Seventy-two patients were identified. Sixty-two patients received CTX/MTX, three CTX/CAPE, two CTX, and five VRL. Median age at diagnosis MBC and at start of MCT was 59.0 years and 64.5 years, respectively. 72.2% tumors were hormone receptor positive and 27.8% were triple-negative. 54.2% patients had more than two different metastases. 80.6% patients showed visceral involvement. 31.9% patients achieved DCR ≥24 weeks. Median PFS was 17.0 weeks (95% CI 14.5-19.5) and median OS was 58.0 weeks (95% CI 29.0-87.0). MCT showed similar DCR ≥24 weeks and clinically meaningful but not statistically significant shorter median PFS compared to prior therapy (31.9% versus 32.8% [p = 0.570] and 17.0 weeks versus 20.0 weeks [p = 0.093], respectively) and statistically significant higher DCR ≥24 weeks and longer median PFS compared to subsequent therapy (31.9% versus 17.4% [p = 0.038] and 17.0 weeks versus 12.0 weeks [p = 0.006], respectively). Three (4.2%) patients terminated MCT because of toxicity.

CONCLUSION

In this real-world retrospective study, MCT was effective and well tolerated and may thus represent a valuable treatment option in selected MBC patients.

Personalised Therapies for Metastatic Triple-Negative Breast Cancer: When Target Is Not Everything

Simple Summary

The purpose of the present review is to shed light on new molecular biomarkers in triple-negative breast cancer (TNBC), showing emerging therapeutic approaches related to specific molecular signatures and their mechanisms of action. A general overview of ongoing clinical trials, future perspectives and differences in approval by American and European regulatory authorities is provided.

Abstract

Triple-negative breast cancer—defined by the absence of oestrogen/progesterone receptors and human epidermal growth factor receptor 2 expression—is a complex and heterogeneous type of tumour characterised by poor prognosis, aggressive behaviour and lack of effective therapeutic strategies. The identification of new biomarkers and molecular signatures is leading to development of new therapeutic strategies including immunotherapy, targeted therapy and antibody-drug conjugates (ADCs). Against a background where chemotherapy has always been considered the standard of care, evolution towards a precision medicine approach could improve TNBC clinical practice in a complex scenario, with many therapeutic options and new drugs. The aim of this review was to focus on emerging therapeutic targets and their related specific therapy, discussing available and emerging drugs, underlining differences in approval by American and European regulatory authorities and showing the future perspective in the large number of ongoing clinical trials.