Oral Metronomic Cyclophosphamide and Methotrexate Plus Fulvestrant in Advanced Breast Cancer Patients: A Mono-Institutional Case-Cohort Report

Nanoformulations-Based Metronomic Chemotherapy: Mechanism, Challenges, Recent Advances, and Future Perspectives

Cancer-related death is a significant health and economic burden worldwide, and some conventional chemotherapy is associated with limited effectiveness in completely curing various cancers, severe adverse effects, and destruction of healthy cells. To overcome the complications associated with conventional treatment, metronomic chemotherapy (MCT) is extensively suggested. In this review, we aim to highlight the importance of MCT over conventional chemotherapeutic approach with emphasis on nanoformulations-based MCT, their mechanism, challenges, recent advances, and future perspectives. Nanoformulations-based MCT revealed remarkable antitumor activity in both preclinical and clinical settings. For example, the metronomic scheduling of oxaliplatin-loaded nanoemulsion and polyethylene glycol-coated stealth nanoparticles incorporating paclitaxel were proven very effective in tumor-bearing mice and rats, respectively. Additionally, several clinical studies have demonstrated the benefit of MCT with acceptable tolerance. Moreover, metronomic might be a promising treatment strategy for improving cancer care in low- and middle-income nations. However, an appropriate alternative to a metronomic regimen for an individual ailment, suitable combinational delivery and scheduling, and predictive biomarkers are certain parts that remain unanswered. Further clinical-based comparative research studies are mandatory to be performed before entailing this treatment modality in clinical practice as alternative maintenance therapy or in place of transferring to therapeutic management.

Metronomic Chemo-Endocrine Therapy (FulVEC) as a Salvage Treatment for Patients with Advanced, Treatment-Refractory ER+/HER2-Breast Cancer-A Retrospective Analysis of Consecutive Patients Data

BACKGROUND

Breast cancer, with 2.3 million new cases and 0.7 million deaths every year, represents a great medical challenge worldwide. These numbers confirm that approx. 30% of BC patients will develop an incurable disease requiring life-long, palliative systemic treatment. Endocrine treatment and chemotherapy administered in a sequential fashion are the basic treatment options in advanced ER+/HER2- BC, which is the most common BC type. The palliative, long-term treatment of advanced BC should not only be highly active but also minimally toxic to allow long-term survival with the optimal quality of life. A combination of metronomic chemotherapy (MC) with endocrine treatment (ET) in patients who failed earlier lines of ET represents an interesting and promising option.

METHODS

The methodology includes retrospective data analyses of pretreated, metastatic ER+/HER2- BC (mBC) patients who were treated with the FulVEC regimen combining fulvestrant and MC (cyclophosphamide, vinorelbine, and capecitabine).

RESULTS

Thirty-nine previously treated (median 2 lines 1-9) mBC patients received FulVEC. The median PFS and OS were 8.4 and 21.5 months, respectively. Biochemical responses (CA-15.3 serum marker decline ≥50%) were observed in 48.7%, and any increase in CA-15.3 was observed in 23.1% of patients. The activity of FulVEC was independent of previous treatments with fulvestrant of cytotoxic components of the FulVEC regimen. The treatment was safe and well tolerated.

CONCLUSIONS

Metronomic chemo-endocrine therapy with FulVEC regimen represents an interesting option and compares favorably with other approaches in patients' refractory to endocrine treatments. A phase II randomized trial is warranted.

Metronomic Chemotherapy

Simple Summary

The present article reviews the state of the art of metronomic chemotherapy use to treat the principal types of cancers, namely breast, non-small cell lung cancer and colorectal ones, and of the most recent progresses in understanding the underlying mechanisms of action. Areas of novelty, in terms of new regimens, new types of cancer suitable for Metronomic chemotherapy (mCHT) and the overview of current ongoing trials, along with a critical review of them, are also provided.

Abstract

Metronomic chemotherapy treatment (mCHT) refers to the chronic administration of low doses chemotherapy that can sustain prolonged, and active plasma levels of drugs, producing favorable tolerability and it is a new promising therapeutic approach in solid and in hematologic tumors. mCHT has not only a direct effect on tumor cells, but also an action on cell microenvironment, by inhibiting tumor angiogenesis, or promoting immune response and for these reasons can be considered a multi-target therapy itself. Here we review the state of the art of mCHT use in some classical tumour types, such as breast and no small cell lung cancer (NSCLC), see what is new regarding most recent data in different cancer types, such as glioblastoma (GBL) and acute myeloid leukemia (AML), and new drugs with potential metronomic administration. Finally, a look at the strategic use of mCHT in the context of health emergencies, or in low –and middle-income countries (LMICs), where access to adequate healthcare is often not easy, is mandatory, as we always need to bear in in mind that equity in care must be a compulsory part of our medical work and research.

De-escalating cancer treatments during COVID 19 pandemic: Is metronomic chemotherapy a reasonable option?

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COVID 19 pandemic represents an emergency for public health services.

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The reorganization of the healthcare system has had an important impact on the management of cancer patients.

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Oral treatments and de-escalation strategies are encouraged.

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Oral metronomic chemotherapy could be a reasonable treatment option in some cancer patients subgroups during COVID 19 pandemic.

COVID 19 pandemic represents an emergency for public health services and containment measures to reduce the risk of infection have been promptly activated worldwide.

The healthcare systems reorganization has had a major impact on the management of cancer patients who are considered at high risk of infection.

Recommendations and guidelines on how to manage cancer patients during COVID 19 pandemic have been published. Oral administration of chemotherapy is recommended to limit the access of cancer patients to hospital facilities and in some cases to guarantee the continuum of care.

Low-dose metronomic administration of chemotherapy with different drugs and schedules has emerged in the last years as a possible alternative to conventional chemotherapy, due to its promising tumor control rates and excellent safety profiles. Moreover, given that many metronomic schedules use the oral route administration, it could represent a therapeutic strategy to ensure continuum of cancer care during COVID 19 pandemic.

In this review we have selected all the clinical studies that have used the metronomic strategy, especially with oral drugs, in order to identify the subgroups of cancer patients who can benefit most from a metronomic approach even during COVID 19 pandemic.

Recent clinical evidence on metronomic dosing in controlled clinical trials: a systematic literature review

Introduction: Metronomic dosing is used to give continuous chemotherapy at low doses. The low doses have minimal side effects and may enable cancer treatment to be remodeled toward the management of chronic disease.Methods: We searched PubMed database to obtain relevant clinical trials studying metronomic chemotherapy (MCT). Our main focus was to find controlled phase II and phase III trials.Results: This systematic review summarizes the results of 91 clinical reports focusing on randomized phase II and phase III clinical studies between 2012 and 2018. During that time, nine randomized phase II and 10 randomized phase III studies were published. In the majority of the studies, MCT was well tolerated, and major side effects were rarely seen. Altogether, 4 phase III studies and 4 randomized phase II studies presented positive results and some clinical benefit.Discussion: Most of the studies did not show significantly improved overall survival or progression-free survival. Typically, the metronomic dosing was explored in a maintenance setup and was added to other agents given within normal high doses, whereas no trial was performed challenging metronomic dosing and best supportive care in later treatment lines. Therefore, there is no definite evidence on the efficacy of single metronomic dosing and firm evidence of metronomic dosing is still missing. There is a need for further confirmation of the usefulness of this approach in clinical practice.

Metronomic chemotherapy combined with endocrine therapy: are we challenging some dogmas?

INTRODUCTION

Metronomic chemotherapy exerts its effects via inhibition of angiogenesis, immune modulation of the tumoral stroma, induction of senescence and apoptosis of tumor cells. Due to its favorable toxicity profile and its oral administration, metronomic chemotherapy arises as a promising alternative to be combined with endocrine therapy for the treatment of patients with luminal breast cancer.

AREAS COVERED

The present manuscript reviews the rationale supporting the combination of metronomic chemotherapy and endocrine therapy, discussing the studies that evaluated this regimen in the treatment of early-stage and metastatic breast cancer patients. Finally, we conclude by providing an expert opinion on the current role and perspectives for the combination of metronomic chemotherapy and endocrine therapy in the management of patients with luminal breast cancer.

EXPERT OPINION

Retrospective series and early-phase clinical trials have shown promising signs of activity and a favorable toxicity profile with this regimen, which warrants further investigation as a treatment option for luminal breast cancer patients.

Low-dose metronomic chemotherapy as an efficient treatment option in metastatic breast cancer-results of an exploratory case-control study

Purpose

There is growing interest in low-dose metronomic chemotherapy (LDMC) in metastatic breast cancer (MBC). In this retrospective case–control analysis, we compared the efficacy of LDMC and conventional chemotherapy (CCT) in MBC.

Methods

Each LDMC patient receiving oral cyclophosphamide (CTX) (50 mg daily) and methotrexate (MTX) (2.5 mg every other day) was matched with two controls who received CCT. Age, number of chemotherapy lines and metastatic sites as well as hormone receptor (HR) status were considered as matching criteria. Primary endpoint was disease control rate longer than 24 weeks (DCR). Secondary endpoints were progression-free survival (PFS), duration of response (DoR) and subgroup analyses using the matching criteria.

Results

40 cases and 80 controls entered the study. 30.0% patients with LDMC and 22.5% patients with CCT showed DCR (p = 0.380). The median PFS was 12.0 weeks in both groups (p = 0.218) and the median DoR was 31.0 vs. 20.5 weeks (p = 0.383), respectively. Among younger patients, DCR was 40.0% in LDMC vs. 25.0% in the CCT group (p = 0.249). DCR was achieved in 33.3% vs. 26.2% non-heavily pretreated patients (p = 0.568) and in 36.0% vs. 18.0% patients without multiple metastases (p = 0.096), respectively. In the HR-positive group, 30.0% LDMC vs. 28.3% CCT patients showed DCR (p = 1.000). Among triple-negative patients, DCR was achieved in 30.0% LDMC and 5.0% CCT patients (p = 0.095).

Conclusions

We demonstrated a similar efficacy of LDMC compared to CCT in the treatment of MBC. Thus, LDMC may be a valuable treatment option in selected MBC patients.

Secondary analyses of the randomized phase III Stop&Go study: efficacy of second-line intermittent versus continuous chemotherapy in HER2-negative advanced breast cancer

Background: Previously, we showed that reintroduction of the same (first-line) chemotherapy at progression could only partially make up for the loss in efficacy as compared to continuously delivered first-line chemotherapy. Here, we report the probability of starting second-line study chemotherapy in the Stop&Go trial, and the progression-free survival (PFS) and overall survival (OS) of patients who received both the first- and second-line treatment in an intermittent versus continuous schedule.Methods: First-line chemotherapy comprised paclitaxel plus bevacizumab, second-line capecitabine or non-pegylated liposomal doxorubicin, given per treatment line as two times four cycles (intermittent) or as eight consecutive cycles (continuous).Results: Of the 420 patients who started first-line treatment within the Stop&Go trial (210:210), a total of 270 patients continued on second-line study treatment (64% of all), which consisted of capecitabine in 201 patients and of non-pegylated liposomal doxorubicin in 69 patients, evenly distributed between the treatment arms. Median PFS was 3.7 versus 5.0 months (HR 1.07; 95% CI: 0.82-1.38) and median OS 10.9 versus 12.4 months (HR 1.27; 95% CI: 0.98-1.66) for intermittent versus continuous second-line chemotherapy. Second-line PFS was positively influenced by prior hormonal therapy for metastatic disease and longer first-line PFS duration, while triple-negative tumor status had a negative influence. Patients with a shorter time to progression (TTP) in first-line (≤10 months) had a higher probability of starting second-line treatment if they received intermittent compared to continuous chemotherapy (OR 1.97; 95% CI: 1.02-3.80).Conclusion: We recommend continuous scheduling of both the first- and second-line chemotherapy for advanced breast cancer.

Metronomic capecitabine with aromatase inhibitors for patients with metastatic hormone-receptor positive, HER2-negative breast cancer

Aim: To evaluate the efficacy and safety of combined metronomic capecitabine with aromatase inhibitors (AIs) for patients with newly diagnosed metastatic hormone-receptor positive, HER2-negative breast cancer. Patients & methods: A total of 41 women with a diagnosis of metastatic hormone-receptor positive, HER2-negative breast cancer received oral metronomic capecitabine, 500 mg/m2 twice daily combined with an AI. Results: After a median follow-up of 24 months (9–50), a median of 15 months of treatment were completed, the median time to progression was 15 months (12.6–17.3) and the median overall survival was 37 months (23.6–50.4). The treatment was tolerated with less than 10% grade 3 toxicities. Conclusion: Combination of metronomic capecitabine and AIs appears to be safe and has encouraging results in advanced hormone-receptor positive, HER2-negative breast cancer.

Metronomic Chemotherapy: A Systematic Review of the Literature and Clinical Experience

Metronomic chemotherapy, continuous and dose-dense administration of chemotherapeutic drugs with lowered doses, is being evaluated for substituting, augmenting, or appending conventional maximum tolerated dose regimens, with preclinical and clinical studies for the past few decades. To date, the principle mechanisms of its action include impeding tumoral angiogenesis and modulation of hosts' immune system, affecting directly tumor cells, their progenitors, and neighboring stromal cells. Its better toxicity profile, lower cost, and easier use are main advantages over conventional therapies. The evidence of metronomic chemotherapy for personalized medicine is growing, starting with unfit elderly patients and also for palliative treatment. The literature reviewed in this article mainly demonstrates that metronomic chemotherapy is advantageous for selected patients and for certain types of malignancies, which make it a promising therapeutic approach for filling in the gaps. More clinical studies are needed to establish a solidified role for metronomic chemotherapy with other treatment models in modern cancer management.

Explorative Analysis of Low-Dose Metronomic Chemotherapy with Cyclophosphamide and Methotrexate in a Cohort of Metastatic Breast Cancer Patients

Background

Low-dose metronomic chemotherapy (LDMC) is increasingly used in metastatic breast cancer (MBC). In this retrospective analysis, we examined the therapeutic effects and side effects of LDMC in a cohort of MBC patients.

Methods

Patients with MBC were included when LDMC with oral cyclophosphamide (CTX) and methotrexate (MTX) was administered between 2009 and 2015. The primary endpoint was disease control rate (DCR) ≥ 24 weeks after the start of LDMC. Secondary endpoints were duration of progression-free survival (PFS), rates of discontinuation due to side effects, and DCR with regard to subgroups.

Results

Retrospective data of 35 patients were available for this analysis. 31% patients achieved DCR. The median PFS was 12 weeks. 9% of patients discontinued LDMC due to adverse events. DCR was 37% in the first 2 lines and 25% in further lines of therapy. 22% of patients with multiple metastases and 35% with ≤2 different metastatic sites achieved DCR. DCR was achieved in 33% of hormone receptor(HR)-positive patients and 27% of HR-negative patients.

Conclusion

The DCR of 31% is in line with the results of previous phase II studies. LDMC was well tolerated. Subgroup analysis was not able to identify a group in which LDMC was more efficient.

Chemosensitization role of fulvestrant in combination with chemotherapy in postmenopausal hormone receptor positive and human epidermal growth factor negative metastatic breast cancer

In metastatic breast cancer (MBC), hormone receptor positive (HR+), human epidermal growth factor negative (HER2-) subtype accounts for the majority. With various new modalities available to prolong life span in this group of patients, the effect is distant from optimum. Prevalent strategy of treating postmenopausal HR+ HER2- MBC is application of chemotherapy (CT) after progression of disease on endocrine therapy (ET) of several lines. Generally, ET targets HR+ ingredients and CT works better with HR- tumor cells. HR+ MBC, though hormone-sensitive, has HR- portion which reacts poorly to ET. Thus, sequential use of ET and CT neglects its insensitive part and gives rise to drug resistance, while alleviation of tumor burden is the top priority in metastatic setting. Chemohormonal therapy (i.e. concomitant use of ET and chemotherapy) complements for the shortcoming of current therapy strategy targeting both HR+ and HR- ingredients theoretically. Fulvestrant, a pure estrogen receptor antagonist and down-regulator, could be a promising agent using concurrently with CT based on chemosensitizing character shown in preclinical and pilot clinical studies. It is hypothesized in this article that chemohormonal therapy with concurrent fulvestrant and CT would be a promising strategy in postmenopausal HR+ HER2- MBC patients. Proof of this hypothesis would help control evolvement of tumor burden and acquirement of drug resistance over a short period of time.

Metronomic Chemotherapy for Metastatic Breast Cancer - a Systematic Review of the Literature

Conventional chemotherapy is generally administered in high doses followed by a treatment-free period to give the body needful time to recover. This "maximum tolerated dose" approach results in high response rates. However, long periods between therapy cycles can lead to development of resistance mechanisms and consequently disease progression. One of the most interesting alternative strategies is metronomic chemotherapy. This concept relies on the continuous administration of chemotherapy at low doses and aims at targeting endothelial cells in the tumor bed as well. Recently, metronomic chemotherapy has been incorporated into the recommendations issued by the German AGO expert panel (www.ago-online.de). A systematic review of PubMed/Medline, ClinicalTrials.gov, the European Clinical Trials Database (EudraCT) and the Cochrane Database was conducted. In the present review, we discuss the current evidence on metronomic chemotherapy in metastatic breast cancer.

Metronomic therapy and breast cancer: a systematic review

Metronomic therapy (MT) refers to repetitive, low doses of chemotherapy drugs. MT exerts an effect not only on tumour cells, but also on their microenvironment. In particular, the low-dose schedule compromises the repairing process of endothelial cells, leading to an anti-angiogenic effect. In addition to the anti-angiogenic effect, MT could have an immunological action through the restoration of the anticancer effect of the immune system and induction of tumour dormancy. Consequently the association of targeted therapy with anti-angiogenic properties or specific immunologic drugs could enhance the efficacy of MT. During the past 15 years, several studies have been published evaluating the metronomic strategy in breast cancer. We conducted a systematic review of the results of phase I, II and III studies testing MT in breast cancer patients. The analyses included the efficacy and toxicity data of MT, and the future development of this strategy in breast cancer are also discussed. The systematic review presented here suggests that MT is a treatment option for breast cancer patients, has a low toxicity profile, efficacy in most patients and has potentially significant cost-effective advantages for public health.

Metronomics: towards personalized chemotherapy?

Since its inception in 2000, metronomic chemotherapy has undergone major advances as an antiangiogenic therapy. The discovery of the pro-immune properties of chemotherapy and its direct effects on cancer cells has established the intrinsic multitargeted nature of this therapeutic approach. The past 10 years have seen a marked rise in clinical trials of metronomic chemotherapy, and it is increasingly combined in the clinic with conventional treatments, such as maximum-tolerated dose chemotherapy and radiotherapy, as well as with novel therapeutic strategies, such as drug repositioning, targeted agents and immunotherapy. We review the latest advances in understanding the complex mechanisms of action of metronomic chemotherapy, and the recently identified factors associated with disease resistance. We comprehensively discuss the latest clinical data obtained from studies performed in both adult and paediatric populations, and highlight ongoing clinical trials. In this Review, we foresee the future developments of metronomic chemotherapy and specifically its potential role in the era of personalized medicine.

Has the time come for metronomics in low-income and middle-income countries?

In 2008, 72% of cancer deaths occurred in low-income and middle-income countries, where, although there is a lower incidence of cancer than in high-income countries, survival rates are also low. Many patients are sent home to die, and an even larger number of patients do not have access to treatment facilities. New constraint-adapted therapeutic strategies are therefore urgently needed. Metronomic chemotherapy--the chronic administration of chemotherapy at low, minimally toxic doses on a frequent schedule of administration, with no prolonged drug-free breaks--has recently emerged as a potential strategy to control advanced or refractory cancer and represents an alternative for patients with cancer living in developing countries. This low-cost, well-tolerated, and easy to access strategy is an attractive therapeutic option in resource-limited countries. Moreover, combined with drug repositioning, additional anticancer effects can be achieved, ultimately resulting in improved cancer control while maintaining minimum cost of treatment. In this Personal View, we will briefly review the rationale behind the combination of metronomic chemotherapy and drug repositioning-an approach we term metronomics. We assess the clinical experience obtained with this kind of anticancer treatment and describe potential new developments in countries with limited resources. We also highlight the need for adapted clinical study endpoints and innovative models of collaboration between for-profit and non-profit organisations, to address the growing problem of cancer in resource-limited countries.

Strategies for improving the clinical benefit of antiangiogenic drug based therapies for breast cancer

Viewed as a whole, the aggregate outcomes of a number of positive randomized phase III clinical trial results evaluating the VEGF-pathway targeting antiangiogenic drug bevacizumab, with or without concurrent chemotherapy, in metastatic breast cancer patients have been disappointingly modest. In the case of antiangiogenic tyrosine kinase inhibitors (TKIs) the results have been negative. Nevertheless, several findings indicate antiangiogenic drugs, especially bevacizumab, are active and can lead to demonstrable clinical benefit in some patients, thus stimulating research into developing strategies to significantly improve their efficacy and reduce toxicity. Some of these initiatives include: 1) discovery and validation of predictive markers that can prospectively identify patients more likely to benefit from antiangiogenic therapy; 2) recognition that the nature of the chemotherapy partner or backbone can strongly impact outcomes when combined with antiangiogenic drugs such as bevacizumab, and thus developing what may be improved combination chemotherapy partner regimens, e.g. metronomic chemotherapy; 3) evaluating prospectively in more depth whether subtypes of the disease-especially triple negative or inflammatory breast cancer-are more responsive to antiangiogenic therapy than other subtypes; 4) evaluating new agents that inhibit angiogenesis in a VEGF-independent manner and other types of drug that can be effectively combined with antiangiogenics, e.g. c-met inhibitors; 5) uncovering the basis of resistance or relapse/progression on the therapy with antiangiogenic drugs; 6) development of improved predictive preclinical breast cancer models for therapy testing, e.g. treatment of mice with established multi-organ breast cancer metastatic disease or genetically engineered mouse models of breast cancer, or mice bearing patient derived breast cancer tissue xenografts.