Metronomic chemotherapy from rationale to clinical studies: a dream or reality?

Precision meets repurposing: Innovative approaches in human papillomavirus and Epstein-Barr virus-driven cancer therapy

Viral malignancies represent a distinct entity among cancers. Oncoviruses like the Human Papilloma Virus (HPV) and the Epstein Barr Virus (EBV) are highly potent inducers of oncogenic transformation leading to tumor development. HPV and EBV are known to be increasingly involved in the pathogenesis of various classes of cancers like cervical, head and neck, colorectal, breast, oral and anogenitial. Therapeutic vaccines directed at such oncoviruses, often fail to unleash the desired immune response against the tumor. This is largely due to the immunosuppressive microenvironment of the virus-induced tumors. Consequently, metronomic chemotherapies administered in conjunction with therapeutic viral vaccines have considerably enhanced the antitumor activity of these vaccines. Moreover, given the unique attributes of HPV and EBV-associated cancers, therapeutic agents directly targeting the oncoproteins of these viruses are still obscure. In this light, an increasing number of reports have evidenced the repurposing of drugs for therapeutic benefits in such cancers. This work delineates the significance and implications of metronomic chemotherapy and drug repurposing in HPV and EBV-associated cancers.

Efficacy and safety of metronomic oral vinorelbine and its combination therapy as second- and later-line regimens for advanced non-small-cell lung cancer: a retrospective analysis

OBJECTIVE

This retrospective analysis aimed to evaluate the efficacy and adverse reactions of metronomic oral vinorelbine and its combination therapy as second- and later-line regimens for advanced non-small-cell lung cancer (NSCLC).

METHODS

NSCLC patients undergoing metronomic oral vinorelbine as second- and later-line regimens in Fujian Cancer Hospital from October 2018 to October 2022 were enrolled, and patients' demographic and clinical characteristics were collected. The efficacy and safety of metronomic oral vinorelbine monotherapy and its combination therapy regimens were compared.

RESULTS

Of 57 study subjects, 63.2% received third- and later-line therapy, with median progression-free survival (mPFS) of 4 months, overall response rate (ORR) of 10.5%, and disease control rate (DCR) of 80.7%. The incidence of therapy-related adverse events was 42.1%, and there was only one case presenting grades 3 and 4 adverse events (1.8%). Among driver gene-negative participants, vinorelbine combination therapy regimens achieved longer mPFS (4.6 vs. 1.2 months, hazards ratio = 0.11, P < 0.0001) and comparable toxicity in relative to metronomic oral vinorelbine, and metronomic oral vinorelbine combined with immune checkpoint inhibitors showed the highest response, with mPFS of 5.6 months (95% CI 4.8 to 6.4 months), ORR of 25%, and DCR of 81.3%. Among participants with gradual resistance to osimertinib, continuing osimertinib in combination with metronomic oral vinorelbine achieved mPFS of 6.3 months (95% CI 0.1 to 12.5 months) and DCR of 86.7%.

CONCLUSION

Metronomic oral vinorelbine and its combination therapy regimens are favorable options as second- and later-line therapy for advanced NSCLC patients, with acceptable efficacy and tolerable toxicity. Vinorelbine combination therapy regimens show higher efficacy and comparable toxicity in relative to metronomic oral vinorelbine, and metronomic oral vinorelbine may have a synergistic effect with immunotherapy and EGFR-TKI targeted therapy.

The inherent fragility of collective proliferative control

Tissues achieve and maintain their sizes through active feedback, whereby cells collectively regulate proliferation and differentiation so as to facilitate homeostasis and the ability to respond to disturbances. One of the best understood feedback mechanisms-renewal control-achieves remarkable feats of robustness in determining and maintaining desired sizes. Yet in a variety of biologically relevant situations, we show that stochastic effects should cause rare but catastrophic failures of renewal control. We define the circumstances under which this occurs and raise the possibility such events account for important non-genetic steps in the development of cancer. We further suggest that the spontaneous stochastic reversal of these events could explain cases of cancer normalization or dormancy following treatment. Indeed, we show that the kinetics of post-treatment recurrence for many cancers are often better fit by a model of stochastic re-emergence due to loss of collective proliferative control, than by deterministic models of cancer relapse.

Metronomic chemotherapy: bridging theory to clinical application in canine and feline oncology

Veterinary oncology has experienced significant evolution over the last few decades, with chemotherapy being currently applied to several neoplasms with therapeutic success. Traditionally, chemotherapy protocols are based on classic cytostatic drugs under the concept of maximum tolerated dose (MTD), which has been associated with a greater risk of toxicity and resistance. Thus, new therapeutic alternatives have emerged, such as metronomic chemotherapy (MC), introducing a new paradigm in cancer treatment. MC consists of administering low doses of chemotherapy drugs continuously over a long period of time, modulating the tumour microenvironment (TME) due to the combination of cytotoxic, antiangiogenic and immunomodulatory effects. This multi-targeted therapy has been described as a treatment option in several canine and feline cancers since 2007, with positive results already published in the literature, particularly in mammary carcinomas and soft tissue sarcomas in dogs. The aim of this review article is to describe the current knowledge about the use of MC in small animal oncology, with emphasis on its mechanisms of action, the most commonly used drugs and clinical outcome.

Metronomic chemotherapy in hematology: Lessons from preclinical and clinical studies to build a solid rationale for future schedules

Metronomic chemotherapy (mCHEMO), based on frequent, regular administration of low, but pharmacologically active drug doses, optimizes antitumor efficacy by targeting multiple targets and reducing toxicity of antineoplastic drugs. This minireview will summarize preclinical and clinical studies on cytotoxic drugs given at weekly, daily, or at continuous metronomic schedules alone or in combination with novel targeted agents for hematological malignancies, including lymphoma, multiple myeloma, and leukemia. Most of the preclinical in vitro and in vivo studies have reported a significant benefit of both mCHEMO monotherapy and combinatorial regimens compared with chemotherapy at the maximum tolerated dose. However, the combination of mCHEMO with targeted drugs is still little explored in the hematologic clinical setting. Data obtained from preclinical studies on low dose metronomic chemotherapy in hematological malignancies clearly suggested the possibility to clinically investigate more tolerable and effective strategies for the treatment of patients with advanced hematological malignancies, or at least for those frail and elderly patients, who are not eligible or resistant to standard treatments.

Evolution and contemporary role of metronomic chemotherapy in the treatment of neuroblastoma

Metronomic chemotherapy refers to the consistent and regular administration of low-dose chemotherapeutic agents over an extended period, with minimal or no extended drug-free intervals. The effectiveness of metronomic chemotherapy is derived from its capacity to impede tumor angiogenesis and foster antitumor immune responses, rather than merely interrupting tumor cell mitosis. Metronomic chemotherapy has been applied in the treatment of neuroblastoma for decades, including patients with newly diagnosed high-risk neuroblastoma and relapsed or refractory neuroblastoma. In the modern era of neuroblastoma treatment, metronomic chemotherapy remains a viable option for maintenance therapy in newly diagnosed neuroblastoma patients without access to autologous stem cell transplantation or immunotherapy, especially in resource-limited regions. For relapsed or refractory patients, metronomic chemotherapy is a suitable alternative for individuals intolerant to intensified treatments or receiving palliative care. Cyclophosphamide, etoposide, vinca alkaloids, and celecoxib constitute the primary components of current metronomic chemotherapy. Given the need for additional research to determine the optimal regimen, comprehensive studies must be conducted to explore and establish standardized metronomic chemotherapy protocols. Additionally, investigating potential biomarkers and clinical prognostic factors is imperative for future advancements in this field.

Metronomic cyclophosphamide for bone marrow carcinomatosis in metastatic castration-resistant prostate cancer

PURPOSE

In some patients with prostate cancer, bone marrow carcinomatosis develops later in the course of the disease, which has a poor prognosis. These are often heavily pretreated patients in the castration-resistant situation for whom there are no other therapeutic options, because either all available systemic therapies have already been used or the use of one is not possible due to the cytopenias associated with bone marrow carcinomatosis. In our literature search, there are no data on this treatment in the setting available, especially no clinical trial or even randomized data. This case series is to determine the clinical efficacy of metronomic cyclophosphamide in patients with metastatic castration-resistant prostate cancer and bone marrow carcinomatosis, particularly with regard to stabilization of the blood count (thrombocytopenias) and thus the possibility of further (more toxic) lines of therapy.

METHODS

Retrospective unicenter analysis was performed on eleven patients between 54 and 84 years of age on metronomic cyclophosphamide for bone marrow carcinomatosis in metastatic castration-resistant prostate cancer treated at a Swiss cancer center between 2014 and 2023.

RESULTS

Eleven patients received metronomic cyclophosphamide for varying periods of time; the majority had severe cytopenias (especially thrombocytopenias). Partially hematologic stabilization was achieved with administration of further systemic therapies.

CONCLUSION

Our case series demonstrates that the use of metronomic cyclophosphamide allows hematologic stabilization for months, benefiting patients who had already received all available therapies for metastatic castration-resistant prostate cancer. Alternatively, it may act as bridging therapy to allow consecutive administration of more toxic therapies with proven survival benefit.

Global trajectory and future prospects of metronomic chemotherapy research: A scientometric analysis (2000-2022)

This scientometric study aimed to provide a first comprehensive overview of the global research landscape of Metronomic Chemotherapy (MC) from 2000 to 2022 using a data-driven approach to identify key trends, collaborations, and potential opportunities. This study highlights the increasing prevalence of MC, with annual outputs increasing substantially over the same timeframe. The United States contributed the most to MC research, followed by Italy and China, while there was a lack of collaborative research efforts between countries and organizations. Through keyword co-occurrence analysis, we identified emerging interdisciplinary research areas, such as "nanoparticles," "immunotherapy," and "antitumor immunity." Our citation analysis identified the most influential authors, institutions, and journals, providing a comprehensive overview of the structure of knowledge and dissemination of MC research. Although the number of publications has decreased since 2019, the analysis indicates that this field has received substantial scholarly attention. These discoveries are extremely important for researchers, funding organizations, and policymakers because they highlight the need for more collaboration, interdisciplinary approaches, and resource allocation in underrepresented fields. This study concludes with recommendations for guiding future research and collaboration, resulting in a larger impact and fostering substantial advancements in MC research.

Using oral tegafur/uracil (UFT) plus leucovorin as adjuvant chemotherapy in stage II colorectal cancer: a propensity score matching study from Taiwan

BACKGROUND

Early-stage colorectal cancer had excellent outcomes after curative resection, typically. However, a perplexing survival paradox between stage II and stage III was noted. This paradox could be influenced by the administration of routine postoperative adjuvant chemotherapy and the presence of high-risk factors in stage II CRC. The objective of the study was to investigate the influence of high-risk factors on patients with stage II CRC and assess the efficacy of oral tegafur/uracil (UFT) plus leucovorin as adjuvant chemotherapy for stage II CRC patients.

METHODS

A retrospective study was conducted using propensity score matching at a single medical institution. A total of 1544 patients with stage II colorectal cancer who underwent radical surgery between January 2004 and January 2009 were included. The intervention used was tegafur/uracil plus leucovorin as adjuvant chemotherapy. The main outcome measures were disease-free survival and overall survival.

RESULTS

After propensity score matching, 261 patients were included in three groups: no-treatment, half-year treatment, and one-year treatment. The clinical characteristics of each group tended to be more consistent. The Cox proportional hazard models showed that tegafur/uracil treatment or not was a significant independent factor for oncological outcome. Kaplan-Meier analysis also showed significantly better disease-free survival and overall survival. Further investigation revealed that tegafur/uracil duration was an independent factor for oncological outcome. While the survival curve did not reach statistical significance, the one-year UFT treatment group demonstrated the best treatment trend.

CONCLUSIONS

This study suggests that tegafur/uracil plus leucovorin is a feasible adjuvant chemotherapy regimen for patients with stage II colorectal cancer after curative surgical treatment. Prolonged tegafur/uracil plus leucovorin treatment for 12 months showed a trend towards better outcomes in patients with stage II colorectal cancer.

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.

Ixazomib, Oral Metronomic Cyclophosphamide, and Dexamethasone for First-Line Treatment of Multiple Myeloma: A Phase II Brown University Oncology Group Study

BACKGROUND

Newly diagnosed multiple myeloma patients have many available treatment options. While lenalidomide, bortezomib, and dexamethasone (RVD) is the preferred initial treatment for many patients, several other agents may provide similar efficacy with less toxicity and improved ease of administration.

METHODS

We evaluated the safety and efficacy of the all-oral regimen of ixazomib, cyclophosphamide, and dexamethasone with the use of metronomic cyclophosphamide dosing in the treatment of patients with newly diagnosed multiple myeloma.

RESULTS

The study was stopped prior to planned enrollment due to slow recruitment, with 12 patients available for final analysis. The overall response rate was 58.3% with 2 patients achieving a very good partial response (16.7%) and 5 patients achieving a partial response (41.7%). Median progression-free survival was 16 months, and median overall survival was 43 months. There were no episodes of grade 3 or greater peripheral neuropathy. Grade 3 or greater dermatologic toxicity was experienced in 50% of patients.

CONCLUSION

Although limited enrollment prevented full efficacy evaluation, our data do not support further study of metronomic cyclophosphamide in combination with ixazomib and dexamethasone in the treatment of newly diagnosed multiple myeloma. The activity of this regimen in the relapsed/refractory setting requires further study (ClinicalTrials.gov Identifier: NCT02412228).

Adjuvant Capecitabine Following Concurrent Chemoradiotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: A Randomized Clinical Trial

Importance

Induction or adjuvant chemotherapy with concurrent chemoradiotherapy (CCRT) are first-line treatment options for treatment of locoregionally advanced nasopharyngeal carcinoma (LA-NPC). Adjuvant platinum regimens are, however, poorly tolerated, highlighting the unmet need for an efficacious, tolerable adjuvant regimen.

Objective

To investigate the efficacy and safety of adjuvant capecitabine with CCRT for the treatment of patients with LA-NPC.

Design, Setting, and Participants

This open-label randomized clinical trial recruited patients from March 31, 2014, to July 27, 2018, at 3 institutions in China, with at least 3 years of follow-up. The data collection cutoff date was February 9, 2022. Eligibility included stage III-IVb nasopharyngeal carcinoma and at least 1 of the following: T3-4N2 or T1-4N3; plasma Epstein-Barr virus DNA titer higher than 20 000 copies/mL; primary gross tumor volume larger than 30.0 cm3; fluorodeoxyglucose F 18 positron emission tomography/computed tomography maximum standard uptake value of the primary gross tumor volume larger than 10.0; or multiple nodal metastases and any larger than 4.0 cm.

Interventions

Patients were randomly assigned 1:1 to receive either capecitabine (1000 mg/m2 twice daily for 14 days every 3 weeks for 8 cycles) or observation following CCRT (100 mg/m2 cisplatin every 3 weeks for 2 to 3 cycles, depending on duration of radiotherapy).

Main Outcomes and Measures

Failure-free survival in the intention-to-treat cohort was assessed using Kaplan-Meier survival curves compared with the log-rank test. Unstratified Cox proportional hazards regression models were used to estimate hazard ratios, with corresponding 95% CIs based on the Wald test.

Results

There were 180 patients enrolled (median [IQR] age, 47 [40-55] years; 143 [79.4%] men). Among 90 patients in the capecitabine group, 76 (84.4%) had at least 2 high-risk factors; among 90 patients in the control group, 80 (88.9%) had at least 2 high-risk factors. All patients completed CCRT, except 1 patient in the capecitabine group who received 1 cycle of cisplatin. Of the 90 patients in the capecitabine group, 85 (94.4%) received capecitabine, with 71 (78.9%) completing 8 cycles. With a median (IQR) follow-up of 58.0 (49.5-80.1) months, 18 events were recorded in the capecitabine group vs 31 events in the control group. Failure-free survival was improved with adjuvant capecitabine (3 years, 83.3% vs 72.2%; 5 years, 78.5% vs 65.9%; hazard ratio, 0.53 [95% CI, 0.30-0.94]; P = .03). The incidence of grade 3 treatment-related adverse events (TRAEs) was higher in the capecitabine group than in the control group (54 of 90 patients [60.0%] vs 46 of 90 patients [51.1%]). Treatment-related adverse events included xerostomia (17 [18.9%] vs 9 [10.0%] patients), mucositis (21 [23.3%] vs 15 [16.7%] patients), and anorexia (8 [8.9%] vs 4 [4.4%] patients). The incidence of grade 3 delayed treatment-related adverse events was comparable in both groups (9 of 83 [10.8%] vs 7 of 81 [8.6%] patients).

Conclusions and Relevance

In this randomized clinical trial, adjuvant capecitabine at the full dose following CCRT was well tolerated and improved failure-free survival among patients with LA-NPC and high-risk factors. Further investigations assessing optimal dose and duration are warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT02143388.

Maintenance tegafur-plus-uracil after adjuvant concurrent chemoradiotherapy may improve outcome for resected oral cavity squamous cell carcinoma with extranodal extension

Objectives

To evaluate whether tegafur-uracil maintenance (UFTm) following postoperation adjuvant cisplatin-based concurrent chemoradiotherapy (CCRT) may reduce distant metastasis in patients with resected oral cavity squamous cell carcinoma (OSCC) with pathologic extranodal extension (pENE+).

Methods

A retrospective comparison was conducted between two cohorts of patients with resected pENE+ OSCC who completed adjuvant CCRT between March 2015 and December 2017, including one cohort of a phase II trial using UFTm and a trial-eligible but off-protocol cohort without using UFTm (non-UFTm) after their adjuvant CCRT. The UFTm trial enrolled patients without relapse within 2 months after the end of adjuvant CCRT and administered UFT 400 mg/day for 1 year. Kaplan-Meier methods estimated the actuarial rate of distant metastasis-free (DMF), locoregional control (LRC), event-free survival (EFS), and overall survival (OS).

Results

A total of 103 patients were included in this study, 64 patients in UFTm and 39 patients in non-UFTm. Severe adverse events in UFTm included grade 3 anemia (n = 1, 1.6%) and grade 3 mucositis (n = 1, 1.6%). A total of 40 (62.5%) patients completed the full course of UFTm, while the remaining terminated UFTm earlier due to disease relapse (n = 14, 21.8%), poor compliance (n = 9, 14.1%), and adverse event (n = 1, 1.6%). The median (range) follow-up time of surviving patients was 43 (22-65) months. The outcomes compared between UFTm and non-UFTm were OS (hazard ratio [HR] 0.31 [95% CI: 0.17-0.57], p < 0·001), EFS (0.45 [0.25-0.82], 0.009), LRC (0.45 [0.19-1.05], 0.067), and DMF (0.47 [0.24-0.95], 0.035). Multivariable analysis, adjusted for UFTm, Charlson comorbidity index score 1-3, site of tongue, and number of ENE+ LN ≧4, confirmed better OS (0.29 [0.16-0.54], <0.001) and EFS (0.47 [0.26-0.85], 0.012) in favor of UFTm over non-UFTm. The 2-year DM rate was 25.8% in UFTm and 44.2% in non-UFTm. For relapsed patients in UFTm vs. non-UFTm, the rate of metastasectomy for oligometastasis was 53% vs. 6%, and the OS was 21.0 (95% CI: 17.8-24.1) months vs. 11.0 (9.1-12.8) months (p < 0.001), respectively.

Conclusions

UFTm may improve the dismal outcomes of the resected pENE+ OSCC. Further investigations are needed to confirm our observations.

Efficacy and Safety of Capecitabine for Triple-Negative Breast Cancer: A Meta-Analysis

Background

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with limited treatment options and poor prognosis. Capecitabine, as a novel adjuvant chemotherapy for TNBCs, remains controversial. Therefore, we conducted this meta-analysis to assess the efficacy and safety of capecitabine for early-stage TNBCs combined with neo-/adjuvant chemotherapy.

Methods

We searched Medline, Embase, Web of Science, and Cochrane databases updated on Mar 18, 2022 for relevant RCTs. In all, 11 RCTs with 5,175 patients were included. We used hazard ratios (HRs) and odds ratios (ORs) to assess the differences between disease-free survival (DFS), overall survival (OS), and adverse events.

Results

Our study demonstrated significance differences in both DFS and OS (DFS: HR=0.77; 95% CI 0.68–0.86; OS: HR=0.73, 95% CI 0.63–0.85). In subgroup analysis, the lower dosage group showed higher DFS (HR=0.79, 95% CI 0.69–0.91), higher frequency (HR=0.72, 95%CI 0.62–0.83), and adjuvant chemotherapy (HR=0.74, 95% CI 0.65–0.84). However, capecitabine was also associated with a higher risk of diarrhea (OR=3.10, 95% CI 2.32–4.15), hand–foot syndrome (OR=25.79, 95% CI 15.32–43.42), and leukopenia (OR=2.08, 95% CI 1.13–3.84).

Conclusion

The addition of capecitabine to early-stage TNBC patients receiving standard adjuvant chemotherapy showed significant DFS and OS improvement with tolerable adverse events. The lower dosage and higher frequency of capecitabine combined with adjuvant chemotherapy demonstrated a better survival outcome.

Toxicity profile, adverse drug reactions and drug-drug interactions among geriatric cancer patients under metronomic chemotherapy in a South Indian tertiary care hospital

OBJECTIVE

The study aims to examine the toxicity profile, pattern of adverse drug reactions (ADRs) and drug-drug interactions (DDIs) in geriatric cancer patients receiving metronomic chemotherapy.

PATIENTS AND METHODS

Patients were followed after each cycle till 12 weeks. Haematological parameters such as complete blood count, liver function test and renal function test were recorded from the baseline to the final visit. The Common Terminology Criteria for Adverse Events (CTCAE) scale was used to characterise the toxicity profile. ADRs that the patients had were documented and assessed for its causality, severity and preventability. The Lexicomp drug interaction checker was used to grade DDIs.

RESULTS

Of 129 patients, according to CTCAE grading, haemoglobin indicated grade 1 toxicity, while other haematological parameters revealed no toxicity. Although there was a statistically significant difference in ALT, alkaline phosphate, serum creatinine and potassium (p < 0.05), it was not clinically significant. A total of 226 ADRs were documented. Anaemia was the most frequently occurred ADR (14%) and Capecitabine caused the highest number of ADRs. Assessments of causality showed that the majority of cases are "possible" (63%). In evaluating the severity of ADRs, 99% ADRs were "mild" and 61% of ADRs were "probably" preventable. Upon assessing the DDIs, 82% of the prescriptions had "no known interaction".

CONCLUSION

Metronomic chemotherapy in geriatric cancer patients exhibited grade 1 toxicity for haemoglobin. Anemia was the most common ADRs. The majority of cases were "possible" in causality, "mild" in severity, and "probably" preventable. The majority of the prescriptions have no known DDIs.

A novel oral metronomic chemotherapy provokes tumor specific immunity resulting in colon cancer eradication in combination with anti-PD-1 therapy

In this study, we investigated the immune-modulating effects of a novel metronomic chemotherapy (MCT) featuring combined oral oxaliplatin (OXA) and pemetrexed (PMX) for colon cancer. OXA and PMX were ionically complexed with lysine derivative of deoxycholic acid (DCK), and incorporated into nanoemulsions or colloidal dispersions, yielding OXA/DCK-NE and PMX/DCK-OP, respectively, to improve their oral bioavailabilities. MCT was not associated with significant lymphotoxicity whereas the maximum tolerated dose (MTD) afforded systemic immunosuppression. MCT was associated with more immunogenic cell death and tumor cell MHC-class I expression than was MTD. MCT improved the tumor antigen presentation of dendritic cells and increased the number of functional T cells in the tumor. MCT also helped to enhance antigen-specific memory responses both locally and systemically. By combining MCT with anti-programmed cell death protein-1 (αPD-1) therapy, the tumor volume was suppressed by 97.85 ± 84.88% compared to the control, resulting in a 95% complete response rate. Upon re-challenge, all tumor-free mice rejected secondary tumors, indicating the induction of a tumor specific memory response. Thus, MCT using an OXA and PMX combination, together with αPD-1, successfully treated colon cancer by activating both innate and adaptive immune cells and elicited tumor-specific long-term immune memory while avoiding toxicity caused by MTD treatment.

Metronomic delivery of orally available pemetrexed-incorporated colloidal dispersions for boosting tumor-specific immunity

In this study, we developed oral pemetrexed (PMX) for metronomic dosing to enhance antitumor immunity. PMX was electrostatically complexed with positively charged lysine-linked deoxycholic acid (DL) as an intestinal permeation enhancer, forming PMX/DL, to enhance its intestinal permeability. PMX/DL was also incorporated into a colloidal dispersion (CD) comprised of the block copolymer of poly(ethylene oxide) and poly(propylene oxide), and caprylocaproyl macrogol-8 glycerides (PMX/DL-CD). CD-containing PMX/DL complex in a 1:1 molar ratio [PMX/DL(1:1)-CD] showed 4.66- and 7.19-fold greater permeability than free PMX through the Caco-2 cell monolayer and rat intestine, respectively. This resulted in a 282% improvement in oral bioavailability in rats. In addition, low-dose metronomic PMX led to more immunogenic cell death in CT26.CL25 cells compared to high PMX concentrations at the maximum tolerated dose. In CT26.CL25 tumor-bearing mice, oral metronomic PMX/DL-CD elicited greater antitumor immunity not only by enhancing the number of tumor-infiltrating lymphocytes but also by suppressing T cell functions. Oral PMX/DL-CD substantially increased programmed cell death protein ligand-1 (PD-L1) expression on tumor cells compared to the control and PMX-IV groups. This increased antitumor efficacy in combination with anti-programmed cell death protein-1 (aPD-1) antibody in terms of tumor rejection and immunological memory compared to the combination of PMX-IV and aPD-1. These results suggest that oral metronomic scheduling of PMX/DL-CD in combination with immunotherapy has synergistic antitumor effects.

Immunotherapy Combined with Metronomic Dosing: An Effective Approach for the Treatment of NSCLC

Simple Summary

Non-small cell lung cancer (NSCLC) claims almost 80% of the total lung cancer cases, with the late-stage disease having an estimated median survival time of up to five years. Patients with NSCLC benefit from traditional maximum tolerated dose (MTD) chemotherapy alone or combined with immunotherapy. However, efficacious such treatment options lead to side effects and poor patient quality of life. We show that metronomic (MTR) chemotherapy—based on the daily administration of chemotherapeutics in low, nontoxic doses—could potentially supplement MTD treatment options and indirectly prevent tumor growth leading to efficacy and less toxicity. Importantly when MTR chemotherapy is combined with an immunotherapy anti-PD1 agent, the anticipated efficacy is achieved with less toxicity, thus providing new options for the treatment of NSCLC.

Abstract

Pioneering studies on tumor and immune cell interactions have highlighted immune checkpoint inhibitors (ICIs) as revolutionizing interventions for the management of NSCLC, typically combined with traditional MTD chemotherapies, which usually lead to toxicities and resistance to treatment. Alternatively, MTR chemotherapy is based on the daily low dose administration of chemotherapeutics, preventing tumor growth indirectly by targeting the tumor microenvironment. The effects of MTR administration of an oral prodrug of gemcitabine (OralGem), alone or with anti-PD1, were evaluated. Relevant in vitro and in vivo models were developed to investigate the efficacy of MTR alone or with immunotherapy and the potential toxicities associated with each dosing scheme. MTR OralGem restricted tumor angiogenesis by regulating thrombospondin-1 (TSP-1) and vascular endothelial growth factor A (VEGFA) expression. MTR OralGem enhanced antitumor immunity by increasing T effector responses and cytokine release, concomitant with dampening regulatory T cell populations. Promising pharmacokinetic properties afforded minimized blood and thymus toxicity and favorable bioavailability upon MTR administration compared to MTD. The combination of MTR OralGem with immunotherapy was shown to be highly efficacious and tolerable, illuminating it as a strong candidate therapeutic scheme for the treatment of NSCLC.

Metronomic oral vinorelbine in previously untreated advanced non-small-cell lung cancer patients unfit for platinum-based chemotherapy: results of the randomized phase II Tempo Lung trial

Background

To assess the efficacy and safety of a metronomic schedule of oral vinorelbine (mVNR) in advanced non-small-cell lung cancer (NSCLC) in patients unfit for platinum-based combination chemotherapy.

Patients and methods

This was a multicenter, prospective, randomized, open-label phase II study in treatment-naive patients with TNM stage IIIB/IV NSCLC. Patients received mVNR at a fixed dose of 50 mg × 3 or standard schedule 60-80 mg/m² weekly until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) without grade 4 toxicity (G4PFS; NCI-CTC v4). Main secondary objectives were safety, disease control rate (DCR) without grade 4 toxicity (G4DCR), DCR, PFS, overall survival (OS) and quality of life (QoL).

Results

A total of 167 patients were included, 83 and 84 patients in the mVNR and standard arms, respectively. The median G4PFS was 4.0 months [95% confidence interval (CI): 2.6-4.3] and 2.2 months (95% CI: 1.5-2.9), hazard ration (HR) = 0.63 (95% CI: 0.45-0.88), P = 0.0068 in favor of metronomic arm; G4DCR was 45.8% and 26.8% in the mVNR and standard arms, respectively. Grade 3-4 treatment-related adverse events were less frequent in the mVNR arm (25.3% versus 54.4%) mainly owing to a reduction in all grades (15.7% versus 51.9%) and grade 3-4 neutropenia (10.8% versus 42%). PFS was 4.3 (95% CI: 3.3-5.1) and 3.9 months (95% CI: 2.8-5.2) in mVNR and standard arms, respectively. No difference in median OS was observed. QoL was comparable between arms.

Conclusions

Metronomic oral vinorelbine significantly prolonged median G4PFS in advanced NSCLC patients unfit for platinum combinations as first-line treatment. It was associated with a clear reduction in toxicity and may be considered as an important option in this challenging population.

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First-line oral vinorelbine prolonged PFS without grade 4 toxicity in platinum-unfit patients with advanced NSCLC.

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Metronomic oral vinorelbine is associated with a clear reduction of grade 3-4 toxicities (mainly hematological ones).

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Metronomic oral vinorelbine allows home treatment and easy tailoring of the treatment according to patient tolerance.

The role of capecitabine-based neoadjuvant and adjuvant chemotherapy in early-stage triple-negative breast cancer: a systematic review and meta-analysis

BACKGROUND

The role of capecitabine in neoadjuvant and adjuvant chemotherapy for early-stage triple-negative breast cancer (TNBC) is highly controversial. Our meta-analysis was designed to further elucidate the effects of capecitabine on survival in early-stage TNBC patients and its safety.

METHODS

PubMed, Embase, and papers presented at several main conferences were searched up to December 19, 2019, to investigate capecitabine-based versus capecitabine-free neoadjuvant and adjuvant chemotherapy in TNBC patients. Heterogeneity was assessed using I2 test, combined with hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CI) computed for disease-free survival (DFS), overall survival (OS), and over grade 3 adverse events (AEs).

RESULTS

A total of 9 randomized clinical trials and 3842 TNBC patients were included. Overall, the combined capecitabine regimens in neoadjuvant and adjuvant chemotherapy showed significantly improved DFS (HR = 0.75; 95% CI, 0.65-0.86; P < 0.001) and OS (HR = 0.63; 95% CI, 0.53-0.77; P < 0.001). In subgroup analysis, there were improvements in DFS in the groups with addition of capecitabine (HR = 0.64; 95% CI, 0.53-0.78; P < 0.001), adjuvant chemotherapy (HR = 0.73; 95% CI, 0.63-0.85; P < 0.001), and lymph node positivity (HR = 0.62; 95% CI, 0.44-0.86; P = 0.005). Capecitabine regimens were related to higher risks of diarrhea (OR = 2.88, 95% CI 2.23-3.74, P < 0.001), stomatitis (OR = 2.01, 95% CI 1.53-2.64, P < 0.001) and hand-foot syndrome (OR = 8.67, 95% CI 6.70-11.22, P < 0.001).

CONCLUSION

This meta-analysis showed that neoadjuvant and adjuvant chemotherapy combined with capecitabine significantly improved both DFS and OS in early-stage TNBC patients with tolerable AEs. There were benefits to DFS in the groups with the addition of capecitabine, adjuvant chemotherapy, and lymph node positivity.

Gene Expression Signatures of a Preclinical Mouse Model during Colorectal Cancer Progression under Low-Dose Metronomic Chemotherapy

Understanding the molecular signatures of colorectal cancer progression under chemotherapeutic treatment will be crucial for the success of future therapy improvements. Here, we used a xenograft-based mouse model to investigate, how whole transcriptome signatures change during metastatic colorectal cancer progression and how such signatures are affected by LDM chemotherapy using RNA sequencing. We characterized mRNAs as well as non-coding RNAs such as microRNAs, long non-coding RNAs and circular RNAs in colorectal-cancer bearing mice with or without LDM chemotherapy. Furthermore, we found that circZNF609 functions as oncogene, since over-expression studies lead to an increased tumor growth while specific knock down results in smaller tumors. Our data represent novel insights into the relevance of non-coding and circRNAs in colorectal cancer and provide a comprehensive resource of gene expression changes in primary tumors and metastases. In addition, we present candidate genes that could be important modulators for successful LDM chemotherapy.

The Evolution and Ecology of Resistance in Cancer Therapy

Despite the continuous deployment of new treatment strategies and agents over many decades, most disseminated cancers remain fatal. Cancer cells, through their access to the vast information of the human genome, have a remarkable capacity to deploy adaptive strategies for even the most effective treatments. We note there are two critical steps in the clinical manifestation of treatment resistance. The first, which is widely investigated, requires molecular machinery necessary to eliminate the cytotoxic effect of the treatment. However, the emergence of a resistant phenotype is not in itself clinically significant. That is, resistant cells affect patient outcomes only when they succeed in the second step of resistance by proliferating into a sufficiently large population to allow tumor progression and treatment failure. Importantly, proliferation of the resistant phenotype is by no means certain and, in fact, depends on complex Darwinian dynamics governed by the costs and benefits of the resistance mechanisms in the context of the local environment and competing populations. Attempts to target the molecular machinery of resistance have had little clinical success largely because of the diversity within the human genome-therapeutic interruption of one mechanism simply results in its replacement by an alternative. Here we explore evolutionarily informed strategies (adaptive, double-bind, and extinction therapies) for overcoming treatment resistance that seek to understand and exploit the critical evolutionary dynamics that govern proliferation of the resistant phenotypes. In general, this approach has demonstrated that, while emergence of resistance mechanisms in cancer cells to every current therapy is inevitable, proliferation of the resistant phenotypes is not and can be delayed and even prevented with sufficient understanding of the underlying eco-evolutionary dynamics.

Toxicity of a methotrexate metronomic schedule in Wistar rats

Metronomic chemotherapy is a relevant strategy that uses low doses of antineoplastic drugs for sustained periods to control tumor growth, an alternative frequently utilized in veterinary patients. This work aimed to evaluate the toxic effects of a metronomic oral dose of methotrexate (MTX) for 45 days in tumor-free Wistar rats when compared with control animals. Clinical alterations, body weight, food, and water intake were monitored daily, and bone marrow suppression, hematological, biochemical, and histopathological analyses were performed at three points (days 30, 45, and 60). MTX-treated animals did not demonstrate severe systemic involvement. At 30 days, compared with control animals, MTX-treated animals showed significant leukocytosis (11.9 ± 2.3 vs. 7.8 ± 0.2 10⁶/μL; P < .05) and augmentation of immature myeloid populations from bone marrow (9.0 ± 0.8 vs. 6.5 ± 1.5%; P < .05), and at 60 days, treated animals showed significant neutrophilia (35.0 ± 11.0 vs. 23.00 ± 3.0%; P < .05), depletion of bone marrow lymphocytes (8.2 ± 0.7 vs. 11.5 ± 1.9%; P < .05), and immature myeloid populations (7.2 ± 0.7 vs. 8.3 ± 0.6%; P < .05). At a histopathological level, splenic hypoplasia and respiratory inflammatory lesions were significant when compared with control animals, presenting mild to moderate myelotoxicity, immune suppression, and associated clinical compromise that persisted beyond treatment withdrawal. This suggested that MTX metronomic toxicity should not be neglected owing to the observed residual side-effects and special care should be taken regarding myelosuppression.

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.

Can we cure stage IV triple-negative breast carcinoma?: Another case report of long-term survival (7 years)

RATIONALE

Triple-negative breast cancer has a dismal prognosis, especially once it has spread to other organs, due to the lack of effective treatments available at this time. Finding an effective treatment for metastatic triple-negative breast cancer remains an unmet medical need.

PATIENT CONCERNS

A 60-year-old woman was diagnosed with stage IIIC triple-negative breast cancer after undergoing a mastectomy. Her mastectomy was followed by adjuvant chemotherapy and radiation therapy. Approximately 1 year later, the patient presented with enlarging lymph nodes in her neck. A biopsy of a left supraclavicular lymph node was positive for recurrent disease. Positron emission tomography and computed tomography scans performed after the biopsy showed metabolic activity in the T6 vertebral body and the right level IIB lymph nodes.

DIAGNOSES

The patient was diagnosed with recurrent metastatic triple-negative breast carcinoma with metastases to the bone and lymph nodes.

INTERVENTIONS

The patient was treated with weekly metronomic chemotherapy, sequential chemotherapy regimens, and immunotherapy.

OUTCOMES

The patient is now 68 years old and 7 years out from her diagnosis of metastatic disease. She achieved a complete response to her treatment and routine scans continue to show no evidence of recurrent disease.

LESSONS

Utilizing sequential weekly metronomic chemotherapy regimens in combination with immunotherapy looks to be a promising treatment option for patients with metastatic triple-negative breast carcinoma. This is a second case where we were able to achieve long-term remission by using the above treatment strategy. These exciting results warrant further investigation of this treatment methodology. We hope that the treatment strategy described in this article can provide an outline for researchers and give patients with this disease more treatment options.

Glioblastoma Treatment Modalities besides Surgery

Glioblastoma multiforme (GBM) is commonly known as the most aggressive primary CNS tumor in adults. The mean survival of it is 14 to 15 months, following the standard therapy from surgery, chemotherapy, to radiotherapy. Efforts in recent decades have brought many novel therapies to light, however, with limitations. In this paper, authors reviewed current treatments for GBM besides surgery. In the past decades, only radiotherapy, temozolomide (TMZ), and tumor treating field (TTF) were approved by FDA. Though promising in preclinical experiments, therapeutic effects of other novel treatments including BNCT, anti-angiogenic therapy, immunotherapy, epigenetic therapy, oncolytic virus therapy, and gene therapy are still either uncertain or discouraging in clinical results. In this review, we went through current clinical trials, underlying causes, and future therapy designs to present neurosurgeons and researchers a sketch of this field.

Anti-Angiogenic Effect of Orally Available Pemetrexed for Metronomic Chemotherapy

Metronomic chemotherapy (MCT) is defined as the frequent administration of low-dose chemotherapeutics, without long drug-free periods, with the exertion of antitumor activity exclusively through anti-angiogenic mechanisms. In this study, we have developed an orally available formulation of pemetrexed (PMX) for MCT. PMX was first complexed ionically with N^α-deoxycholyl-l-lysyl-methylester (DCK) as the permeation enhancer. This was followed by dispersion with poloxamer 188 and Labrasol to form the solid oral formulation of PMX (PMX/DCK-OP). PMX/DCK-OP exhibited a 10.6-fold increase in permeability across a Caco-2 cell monolayer compared to PMX alone. This resulted in a 70-fold increase in the oral bioavailability of PMX/DCK-OP in mice over oral PMX alone. In the A549 xenograft model, tumor volume was reduced by 51.1% in the PMX/DCK-OP treated group compared to only 32.8% in the maximum tolerated dose (MTD)-treated group. Furthermore, PMX/DCK-OP exhibited a significant anti-angiogenic effect on the A549 xenograft mice when compared to the MTD-treated group, as indicated by microvessel density quantification for CD-31. In addition, PMX/DCK-OP enhanced the release of an endogenous angiogenesis inhibitor, thrombospondin-1 (TSP-1), into both the blood circulation and the tumor microenvironment. Therefore, due to its oral route of administration, PMX/DCK-OP appears to be a better alternative to the conventional treatment of PMX.

Case report of long-term survival with metastatic triple-negative breast carcinoma: Treatment possibilities for metastatic disease

RATIONALE

Breast cancer is the most common as well as one of the most devastating cancers among women in the United States. Prognosis is poor for patients with metastatic breast cancer, especially for patients with so-called "triple-negative" disease. The lack of effective therapies for metastatic triple-negative breast cancer outlines the need for novel and innovative treatment strategies.

PATIENT CONCERNS

A 58-year-old underwent a mastectomy which revealed a recurrent triple-negative breast carcinoma. Afterward, she presented with a growing mass in her left axilla and chest wall. A computed tomography scan showed axillary and supraclavicular adenopathy, nodules in the left upper and lower lobe of the lungs, and 2 areas of disease in the liver. A bone scan showed lesions in the ribs.

DIAGNOSIS

The patient was diagnosed with a recurrent metastatic triple-negative breast carcinoma that spread to the lung, liver, and bones.

INTERVENTIONS

The patient was treated with metronomic chemotherapy, sequential chemotherapy regimens, and immunotherapy.

OUTCOMES

The patient is now over 15 years out from her diagnosis of metastatic disease without any evidence of recurrent disease, likely due to the patient's treatment strategy which included sequential metronomic chemotherapy regimens and immunotherapy.

LESSONS

Sequential metronomic chemotherapy regimens in combination with immunotherapy might be an effective treatment option for patients with metastatic triple-negative breast cancer. We hope that this case can provide some guidance for the treatment of metastatic triple-negative breast cancer and motivate research that can potentially lead to more cases of long-term survival for patients who develop this dismal disease.

Management of recurrent nasopharyngeal carcinoma: current perspectives

Nasopharyngeal carcinoma is a rare disease in Western countries. Nevertheless, its incidence in China, Singapore, and other Eastern countries reaches 20 cases per 100,000 people. Being an extremely chemo- and radiosensitive disease, upfront treatment often consists in the association of intensity-modulated radiation therapy and concurrent cisplatin. Unfortunately, about 20% of the patients suffer from a radioresistant disease which recurs after upfront therapy. For these patients, mainly available therapeutic options consist in systemic therapy, in particular poly-chemotherapy. In those showing a single locoregional recurrence, chemotherapy is not considered to be the preferred approach and other different strategies may be employed. Re-irradiation and surgery are strategies that are always used more often, albeit related to high risk of morbidity. Immunotherapy and targeted therapy, such as heavy ions-based re-irradiations, are experimental but very intriguing options.

Low-dose eribulin reduces lung metastasis of osteosarcoma in vitro and in vivo

Lung metastasis markedly reduces the prognosis of osteosarcoma. Moreover, there is no effective treatment for lung metastasis, and a new treatment strategy for the treatment of osteosarcoma lung metastasis is required. Therefore, in this study, we investigated the suppressive effect of the microtubule inhibitor eribulin mesylate (eribulin) on lung metastasis of osteosarcoma. At concentrations >proliferation IC₅₀, eribulin induced cell cycle arrest and apoptosis in a metastatic osteosarcoma cell line, LM8. However, at concentrations <proliferation IC₅₀, (low dose), eribulin changed cell morphology and decreased LM8 migration. Low eribulin concentrations also reduced directionality during migration, peripheral localization of adenomatous polyposis coli protein, and turnover of focal adhesions. In a three-dimensional collagen culture system, low eribulin concentrations inhibited tumor cell proliferation and colony formation. Higher doses of eribulin administered on a standard schedule inhibited lung metastasis and primary tumor growth in a murine osteosarcoma metastasis model. Frequent low-dose eribulin administration (0.3 mg/kg every 4 days × 4) effectively inhibited lung metastasis but had little effect on primary tumor growth. Overall, our results indicate that eribulin could reduce osteosarcoma lung metastasis.

Tumor endothelial cells as a potential target of metronomic chemotherapy

Drug resistance and toxic side effects are major therapeutic hurdles affecting cancer patients receiving conventional chemotherapy based on the maximum tolerated dose. Metronomic chemotherapy (MCT), a new therapeutic approach developed to avoid these problems generally, consists of the continuous administration of low-dose cytotoxic agents without extended intervals. This therapy targets the tumor microenvironment, rather than exerting a direct effect on tumor cells. As a result, the MCT regimen functionally impairs tumor endothelial cells and circulating endothelial progenitor cells, leading to tumor dormancy via anti-angiogenesis. Over the past 10 years, several studies have highlighted the impact of MCT on the tumor microenvironment and angiogenesis and demonstrated its potential as a switch from the pro-angiogenic to the anti-angiogenic state. However, the mechanisms of action are still obscure. Here, we systematically review the evidence regarding the anti-angiogenic potential of MCT as a crucial determinant of tumor dormancy and cancer treatment.

Oral vinorelbine-based concomitant chemoradiotherapy in unresectable stage III non-small cell lung cancer: a systematic review

INTRODUCTION

Cisplatin-based chemotherapy administered concomitantly to thoracic radiotherapy is the treatment recommended by the European guidelines for fit patients with unresectable stage III non-small cell lung cancer (NSCLC). Cisplatin may be combined with etoposide, vinorelbine or other vinca alkaloids, which act also as radiation sensitizers. Initially administered intravenously, vinorelbine is also available as oral formulation and is the only orally available microtubule-targeting agent. In addition, the oral formulation avoids the risk of extravasation and phlebitis. Areas covered: A literature search has been performed for articles reporting phase II-III trials aimed to evaluate efficacy and safety of oral vinorelbine-based chemoradiotherapy in unresectable locally advanced NSCLC. Expert commentary: In a series of trials with various protocols published from 2008 to 2018, mostly phase II studies, oral vinorelbine demonstrated a significant activity in concomitant chemoradiotherapy for unresectable locally advanced NSCLC typically as part of combination schedules with cisplatin. Main toxicities were hematologic (neutropenia and anemia); non-hematological toxicities included esophagitis and gastro-duodenal adverse events. Large prospective phase III trials are needed to confirm the role of vinorelbine-based chemotherapy associated to thoracic radiotherapy in unresectable stage III NSCLC and more particularly trials with metronomic oral vinorelbine.

The Evolution and Ecology of Resistance in Cancer Therapy

Despite continuous deployment of new treatment strategies and agents over many decades, most disseminated cancers remain fatal. Cancer cells, through their access to the vast information of human genome, have a remarkable capacity to deploy adaptive strategies for even the most effective treatments. We note there are two critical steps in the clinical manifestation of treatment resistance. The first, which is widely investigated, requires deployment of a mechanism of resistance that usually involves increased expression of molecular machinery necessary to eliminate the cytotoxic effect of treatment. However, the emergence of a resistant phenotype is not in itself clinically significant. That is, resistant cells affect patient outcomes only when they form a sufficiently large population to allow tumor progression and treatment failure. Importantly, proliferation of the resistant phenotype is by no means certain and, in fact, depends on complex Darwinian dynamics governed by the costs and benefits of the resistance mechanisms in the context of the local environment and competing populations. Attempts to target molecular machinery of resistance have had little clinical success largely because of the diversity within the human genome-therapeutic interruption of one mechanism simply results in its replacement by an alternative. We explore an alternative strategy for overcoming treatment resistance that seeks to understand and exploit the critical evolutionary dynamics that govern proliferation of the resistant phenotypes. In general, this approach has shown that, although emergence of resistance mechanisms in cancer cells to every current therapy is inevitable, proliferation of the resistant phenotypes is not and can be delayed and even prevented with sufficient understanding of the underlying ecoevolutionary dynamics.

Inhibition of tumor growth by cancer vaccine combined with metronomic chemotherapy and anti-PD-1 in a pre-clinical setting

Tumor microenvironment (TME) is characterized by multiple immune suppressive mechanisms able to suppress anti-tumor effector cell immunity. Combinatorial strategies, including vaccine and immunomodulatory drugs, need to be developed for improved immunotherapy efficacy. A novel combinatorial approach was assessed in C57BL/6 mice injected with mouse melanoma B16F10 cells. A multi-peptide vaccine (PEPT) was combined with a low dose metronomic chemotherapy (MCT) and an anti-PD-1 checkpoint inhibitor (CI). Statistical analysis were performed with the unpaired two-sided Student's t-test and ANOVA. Animals treated with the multi-peptide vaccine combined with MCT or CI showed remarkable delay in tumor growth and prolonged survival as compared to control groups. The multi-pronged combination including PEPT+MCT+CI was able to prolong survival in all mice and inhibit tumor growth in 66.6% of mice. All animals which did not show tumor growth were re-challenged with the same melanoma cells and one of them showed complete tumor growth inhibition. The anti-tumor effect was associated with strong T cell immune response to vaccine mutated peptides and significant reduction of regulatory T cells. The combination of a vaccine with MCT and CI was highly efficient in potentiating the vaccine's anti-tumor effects. The approach is highly promising to be moved into clinical trial.

Metronomic chemotherapy for non-metastatic triple negative breast cancer: Selection is the key

Triple negative breast cancer (TNBC) accounts for 15%-20% of all breast cancer, and is still defined as what it is not. Currently, TNBC is the only type of breast cancer for which there are no approved targeted therapies and maximum tolerated dose chemotherapy with taxanes and anthracycline-containing regimens is still the standard of care in both the neoadjuvant and adjuvant settings. In the last years, metronomic chemotherapy (MC) is being explored as an alternative to improve outcomes in TNBC. In the neoadjuvant setting, purely metronomic and hybrid approaches have been developed with the objective of increasing complete pathologic response (pCR) and prolonging disease free survival. These regimens proved to be very effective achieving pCR rates between 47%-60%, but at the cost of great toxicity. In the adjuvant setting, MC is used to intensify adjuvant chemotherapy and, more promisingly, as maintenance therapy for high-risk patients, especially those with no pCR after neoadjuvant chemotherapy. Considering the dismal prognosis of TNBC, any strategy that potentially improves outcomes, specially being the oral agents broadly available and inexpensive, should be considered and certainly warrants further exploration. Finally, the benefit of MC needs to be validated in properly designed clinical trials were the selection of the population is the key.

Metronomic treatment in immunocompetent preclinical GL261 glioblastoma: effects of cyclophosphamide and temozolomide

Glioblastoma (GBM) causes poor survival in patients even when applying aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment, but resistance always ensues. In previous years, efforts have focused on new therapeutic regimens with conventional drugs to activate immune responses that may enhance tumor regression and prevent regrowth, for example the "metronomic" approaches. In metronomic scheduling studies, cyclophosphamide (CPA) in GL261 GBM growing subcutaneously in C57BL/6 mice was shown not only to activate antitumor CD8⁺ T-cell response, but also to induce long-term specific T-cell tumor memory. Accordingly, we have evaluated whether metronomic CPA or TMZ administration could increase survival in orthotopic GL261 in C57BL/6 mice, an immunocompetent model. Longitudinal in vivo studies with CPA (140 mg/kg) or TMZ (range 140-240 mg/kg) metronomic administration (every 6 days) were performed in tumor-bearing mice. Tumor evolution was monitored at 7 T with MRI (T₂ -weighted, diffusion-weighted imaging) and MRSI-based nosological images of response to therapy. Obtained results demonstrated that both treatments resulted in increased survival (38.6 ± 21.0 days, n = 30) compared with control (19.4 ± 2.4 days, n = 18). Best results were obtained with 140 mg/kg TMZ (treated, 44.9 ± 29.0 days, n = 12, versus control, 19.3 ± 2.3 days, n = 12), achieving a longer survival rate than previous group work using three cycles of TMZ therapy at 60 mg/kg (33.9 ± 11.7 days, n = 38). Additional interesting findings were, first, clear edema appearance during chemotherapeutic treatment, second, the ability to apply the semi-supervised source analysis previously developed in our group for non-invasive TMZ therapy response monitoring to detect CPA-induced response, and third, the necropsy findings in mice cured from GBM after high TMZ cumulative dosage (980-1400 mg/kg), which demonstrated lymphoma incidence. In summary, every 6 day administration schedule of TMZ or CPA improves survival in orthotopic GL261 GBM with respect to controls or non-metronomic therapy, in partial agreement with previous work on subcutaneous GL261.

Anti-angiogenic and anti-tumor effects of metronomic use of novel liposomal zoledronic acid depletes tumor-associated macrophages in triple negative breast cancer

Zoledronic acid (ZOL) has been used as an adjuvant therapy for breast cancer. It is suggested that ZOL might be associated with inhibition of macrophages, which in turn reduces tumor growth, metastasis and tumor angiogenesis. Moreover, metronomic therapy can inhibit tumor angiogenesis and tumor immune cells. Previously we developed ZOL based cationic liposomes that allowed a higher intratumor delivery of drug compared with free ZOL in vivo. Therefore, in this study, Asn-Gly-Arg (NGR) and PEG2000 were used as ligands to modify the surface of liposomes (NGR-PEG-LP-ZOL) in metronomic therapy to clear the tumor-associated macrophages (TAMs) and inhibit the formation of tumor angiogenesis, achieving the purpose of anti-tumor growth.

Our data showed that NGR-PEG-LP-ZOL metronomic therapy has the strongest inhibitory effect on tumor growth. Further, NGR-PEG-LP-ZOL metronomic therapy could significantly impair TAMs by inhibiting the expression of CD206 antibody in tumor tissues, decreasing the expression of cytokine related gene expression of TAMs, as well as reducing the percentage of TAMs in tumor tissues. In addition, NGR-PEG-LP-ZOL metronomic therapy could significantly inhibit the expression of tumor neovascular specific antibody CD31 and reduce the microvessel density. In conclusion, our study demonstrated that NGR-PEG-LP-ZOL metronomic therapy could impair TAMs by inhibiting tumor angiogenesis and enhance the antitumor effect of ZOL.

Slow release of etoposide from dextran conjugation shifts etoposide activity from cytotoxicity to differentiation: A promising tool for dosage control in anticancer metronomic therapy

Drug conjugation, improving drug stability, solubility and body permanence, allows achieving impressive results in tumor control. Here, we show that conjugation may provide a straightforward method to administer drugs by the emerging anticancer metronomic approach, presently consisting of low, repeated doses of cytotoxic drugs used in traditional chemotherapy, thus reducing toxicity without reducing efficiency; however, low dose maintenance in tumor sites is difficult. We show that conjugating the antitumor drug etoposide to dextran via pH-sensitive bond produces slow releasing, apoptosis-proficient conjugates rapidly internalized into acidic lysosomes; importantly, release of active etoposide requires cell internalization and acidic pH. Conjugation, without impairing etoposide-induced complete elimination of tumor cells, shifted the mode of apoptosis from cytotoxicity- to differentiation-related; interestingly, high conjugate doses acted as low doses of free etoposide, thus mimicking the effect of metronomic therapy. This indicates slow release as a promising novel strategy for stabilizing low drug levels in metronomic regimens.

Immunotherapeutic approaches for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a cancer with a high mortality rate due to the fact that the diagnosis usually occurs at anadvanced stage. Even in case of curative surgical treatment, recurrence is common. Sorafenib and regorafenib are the only therapeutic agents that have been demonstrated to be effective in advanced HCC, thus novel curative approaches are urgently needed. Recent studies focus on the role of immune system in HCC. In fact, the unique immune response in the liver favors tolerance, which can represent a real challenge for conventional immunotherapy in these patients. Spontaneous immune responses against tumor antigens have been detected, and new immune therapies are under investigation: dendritic cell vaccination, immune-modulator strategy, and immune checkpoint inhibition. In recent years different clinical trials examining the use of immunotherapy to treat HCC have been conducted with initial promising results. This review article will summarize the literature data concerning the potential immunotherapeutic approaches in HCC patients.

Metronomic oral cyclosphosphamide as third-line systemic treatment or beyond in patients with inoperable locoregionally advanced recurrent or metastatic nasopharyngeal carcinoma

There is no standard third-line or further systemic treatment for patients with inoperable locoregionally advanced recurrent or metastatic nasopharyngeal carcinoma (NPC). Metronomic oral cyclophosphamide provides an acceptable and cheap option for these heavily pretreated patients who had limited choices. We conducted a prospective phase II single-arm open-label study of metronomic oral cyclophosphamide. Patients with locoregionally advanced recurrent inoperable (rT3/T4, rN2-N3b) or metastatic (rM1) NPC who had Eastern Cooperative Oncology Group (ECOG) performance status (PS) (0-2) and had progressed after at least 2 lines of palliative systemic chemotherapy were eligible. They received oral cyclophosphamide between 50 and 150 mg once daily until progressive disease or unacceptable toxicity. Objective response rate (ORR), disease control rate (DCR), biochemical response (two consecutive declines of plasma EBV DNA after treatment), progression-free survival (PFS), overall survival (OS), and safety profiles were evaluated. A total of 56 patients were recruited. Thirty-three, 13, 6, 3, and 1 patients received cyclophosphamide as 3rd, 4th, 5th, 6th, and 7th line of therapy respectively. After a median follow-up of 9.95 months (range 1.76-59.51 months), the ORR was 8.9% and the DCR was 57.1%. The median PFS and OS were 4.47 and 9.20 months, respectively. Those with PS 1 had longer median PFS (5.49 months) compared to those with PS 2 (3.75 months, P = .011). Besides, those who had locoregionally recurrent disease had better PFS (8.97 months, 95% CI, 0.53-17.41 months) compared to those who had distant metastases (4.14 months, 95% CI, 2.53-5.75 months, P = .020). Multivariable analysis revealed that PS 1 (vs 2) (P = .020) and locoregional recurrence (vs metastasis) (P = .029) were the only significant independent prognostic factors of PFS. Around 16 (28.6%) patients developed grade ≥3 adverse events, including malaise (5.4%), hematological (8.9%), gastrointestinal (3.6%), feverish (3.6%), and hemorrhagic (1.8%) events. The median cost of the whole drug treatment was 51.65 US dollars (USD) (range 4.15-142.75 USD) (1 USD = 7.8 HK dollars [HKD]). Metronomic oral cyclophosphamide is an acceptable third-line or beyond systemic therapy for locoregionally advanced recurrent or metastatic NPC with acceptable toxicity and limited financial burden.

Metronomic treatment of advanced non-small-cell lung cancer with daily oral vinorelbine - a Phase I trial

Micro-abstract

In a Phase I dose-finding study of metronomic daily oral vinorelbine in advanced non-small-cell lung cancer, a recommended dose was established for this therapeutic approach. In addition, this trial revealed promising efficacy data and an acceptable tolerability profile. The observed vinorelbine blood concentrations suggest continuous anti-angiogenic coverage.

Introduction

We present a Phase I dose-finding study investigating metronomic daily oral vinorelbine (Navelbine^® Oral, NVBo) in advanced non-small-cell lung cancer (NSCLC).

Patients and methods

Patients with stage III/IV NSCLC received daily NVBo at fixed dose levels of 20–50 mg/d for 21 days of each 4-week cycle. Primary end point was the maximum tolerated dose. Secondary end points included tumor response, time to progression (TTP), overall survival (OS) and tolerability.

Results

Twenty-seven patients with advanced NSCLC were enrolled. Most of them were extensively pretreated. Daily NVBo was well tolerated up to 30 mg/d. At 40 mg/d, two of five patients experienced dose-limiting toxicities (DLTs). Three of six patients had DLTs at the 50 mg/d level. The recommended dose was established at 30 mg/d in cycle 1, with escalation to 40 mg/d in cycle 2, if tolerated. Pharmacokinetic analyses showed continuous blood exposure over 21 days and only marginal accumulation. The tolerability profile was acceptable (all dose levels – all grades: decreased appetite 33%, diarrhea 33%, leukopenia 33%, nausea 30%, vomiting 26%; ≥grade 3: leukopenia 30%, lymphopenia 19%, neutropenia 19%, febrile neutropenia 15%). Disease control rate, OS and TTP signaled a treatment effect.

Conclusion

Daily metronomic NVBo therapy in extensively pretreated patients with advanced NSCLC is feasible and safe at the recommended dose of 30 mg/d. Escalation to 40 mg/d in the second cycle is possible. The blood concentrations of vinorelbine after daily metronomic dosing reached lower peaks than intravenous or oral conventional dosing. Blood concentrations were consistent with anti-angiogenic or immune modulating pharmacologic properties of vinorelbine. Further studies are warranted to evaluate the safety and efficacy of this novel approach in specific patient populations.

Metronomic capecitabine versus best supportive care as second-line treatment in hepatocellular carcinoma: a retrospective study

Preliminary studies suggest that capecitabine may be safe and effective in HCC patients. The aim of this study was to retrospectively evaluate the safety and efficacy of metronomic capecitabine as second-line treatment. This multicentric study retrospectively analyzed data of HCC patients unresponsive or intolerant to sorafenib treatment with metronomic capecitabine or best supportive care (BSC).Median progression free survival was 3.1 months in patients treated with capecitabine (95%CI: 2.7-3.5). Median overall survival was 12.0 months (95% CI: 10.7-15.8) in patients receiving capecitabine, while 9.0 months (95% CI: 6.5-13.9) in patients receiving BSC. The result of univariate unweighted Cox regression model shows a 46% reduction in death risk for patients on capecitabine (95%CI: 0.357-0.829; p  =0.005) compared to patients receiving BSC alone. After weighting for potential confounders, death risk remained essentially unaltered (45%; 95%CI: 0.354-0.883; p = 0.013). Metronomic capecitabine seems a safe second-line treatment for HCC patients in terms of management of adverse events, showing a potential anti-tumour activity which needs further evaluation in phase III studies.

Targeting Protein Kinase CK2: Evaluating CX-4945 Potential for GL261 Glioblastoma Therapy in Immunocompetent Mice

Glioblastoma (GBM) causes poor survival in patients even with aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for GBM treatment but resistance always ensues. Protein kinase CK2 (CK2) contributes to tumour development and proliferation in cancer, and it is overexpressed in human GBM. Accordingly, targeting CK2 in GBM may benefit patients. Our goal has been to evaluate whether CK2 inhibitors (iCK2s) could increase survival in an immunocompetent preclinical GBM model. Cultured GL261 cells were treated with different iCK2s including CX-4945, and target effects evaluated in vitro. CX-4945 was found to decrease CK2 activity and Akt(S129) phosphorylation in GL261 cells. Longitudinal in vivo studies with CX-4945 alone or in combination with TMZ were performed in tumour-bearing mice. Increase in survival (p < 0.05) was found with combined CX-4945 and TMZ metronomic treatment (54.7 ± 11.9 days, n = 6) when compared to individual metronomic treatments (CX-4945: 24.5 ± 2.0 and TMZ: 38.7 ± 2.7, n = 6) and controls (22.5 ± 1.2, n = 6). Despite this, CX-4945 did not improve mice outcome when administered on every/alternate days, either alone or in combination with 3-cycle TMZ. The highest survival rate was obtained with the metronomic combined TMZ+CX-4945 every 6 days, pointing to the participation of the immune system or other ancillary mechanism in therapy response.

Metronomic chemotherapy and immunotherapy in cancer treatment

Systemic chemotherapy given at maximum tolerated doses (MTD) has been the mainstay of cancer treatment for more than half a century. In some chemosensitive diseases such as hematologic malignancies and solid tumors, MTD has led to complete remission and even cure. The combination of maintenance therapy and standard MTD also can generate good disease control; however, resistance to chemotherapy and disease metastasis still remain major obstacles to successful cancer treatment in the majority of advanced tumors. Metronomic chemotherapy, defined as frequent administration of chemotherapeutic agents at a non-toxic dose without extended rest periods, was originally designed to overcome drug resistance by shifting the therapeutic target from tumor cells to tumor endothelial cells. Metronomic chemotherapy also exerts anti-tumor effects on the immune system (immunomodulation) and tumor cells. The goal of immunotherapy is to enhance host anti-tumor immunities. Adding immunomodulators such as metronomic chemotherapy to immunotherapy can improve the clinical outcomes in a synergistic manner. Here, we review the anti-tumor mechanisms of metronomic chemotherapy and the preliminary research addressing the combination of immunotherapy and metronomic chemotherapy for cancer treatment in animal models and in clinical setting.

CT Perfusion as an Early Biomarker of Treatment Efficacy in Advanced Ovarian Cancer: An ACRIN and GOG Study

Purpose: ACRIN 6695 was a feasibility study investigating whether CT perfusion (CTP) biomarkers are associated with progression-free survival (PFS) at 6 months (PFS-6) in patients with advanced ovarian cancer who were treated with carboplatin and either dose-dense (weekly) or conventional (3-weekly) paclitaxel, with optional bevacizumab in the prospective phase III GOG-0262 trial.Experimental Design: ACRIN 6695 recruited participants with residual disease after primary cytoreductive surgery or planned interval cytoreduction following neoadjuvant therapy, to undergo CTP studies before (T0), 3 weeks (T1), and 4 weeks (T2) after chemotherapy initiation. Tumor blood flow (BF) and blood volume (BV) were derived with commercial software. Fisher exact tests assessed the associations of CTP biomarkers changes from T0 to T2 dichotomized at zero with PFS-6 and overall radiographic response rate, while Cox regression assessed the associations between CTP biomarker changes and PFS and overall survival (OS). Bonferroni correction was used to account for multiple comparisons.Results: Seventy-six of 120 enrolled patients from 19 centers were evaluable with a median age of 61 years. BV increase was significantly associated with lower chance of PFS-6 (P = 0.028), while BF achieves borderline significance (P = 0.053). In addition, BF increase was associated with shorter PFS (HR 2.9, 95% CI, 1.3-6.4, P = 0.008) and remained significant after adjusting for age, change in tumor volume, and surgery status (P = 0.007). Neither BF nor BV changes were significantly associated with treatment response rate or OS.Conclusions: Early CTP biomarkers measurement may provide early prognostic information for PFS in newly diagnosed ovarian cancer. Clin Cancer Res; 23(14); 3684-91. ©2017 AACR.