Metronomic Chemotherapy in Elderly Patients.

PURPOSE OF REVIEW: This review describes the most relevant studies found in the scientific literature regarding metronomic chemotherapy (MCT) in the geriatric oncology population to support its use as a feasible treatment of care in the frail elderly patients. RECENT FINDINGS: Recent years have seen a reevaluation of cancer chemotherapeutic drugs and MCT is an emerging schedule in phase II and III clinical trials. Ageing is one of the risk factors for the development of cancer, the incidence of whom increases dramatically in people who live longer. To date, standard oncological protocols involve chemotherapeutic drugs in short cycles of therapy at the maximum tolerated dose (MTD). Although these therapeutic regimens may be successful, they can cause important adverse drug reactions, especially in elderly or frail patients. MCT is a different modality of delivery of chemotherapeutic drugs (frequent low dose for prolonged time) and it looks at the overcoming of the limitations and disadvantages of MTD, in particular the toxicity aspect. We reviewed the experience of clinicians who have used MCT in clinical trials enrolling elderly patients with different cancer types.

Melanocortin receptor 4 as a new target in melanoma therapy: Anticancer activity of the inhibitor ML00253764 alone and in association with B-raf inhibitor vemurafenib.

The aim of our study is to investigate in vitro and in vivo MC4R as a novel target in melanoma using the selective antagonist ML00253764 (ML) alone and in combination with vemurafenib, a B-rafV600E inhibitor. The human melanoma B-raf mutated A-2058 and WM 266-4 cell lines were used. An MC4R null A-2058 cell line was generated using a CRISPR/Cas9 system. MC4R protein expression was analysed by western blotting, immunohistochemistry, and immunofluorescence. Proliferation and apoptotic assays were performed with ML00253764, whereas the synergism with vemurafenib was evaluated by the combination index (CI) and Loewe methods. ERK1/2 phosphorylation and BCL-XL expression were quantified by western blot. In vivo experiments were performed in Athymic Nude-Foxn1nu male mice, injecting subcutaneously melanoma cells, and treating animals with ML, vemurafenib and their concomitant combination. Comet and cytome assays were performed. Our results show that human melanoma cell lines A-2058 and WM 266-4, and melanoma human tissue, express functional MC4R receptors on their surface. MC4R receptors on melanoma cells can be inhibited by the selective antagonist ML, causing antiproliferative and proapoptotic activity through the inhibition of phosphorylation of ERK1/2 and a reduction of BCL-XL. The concomitant combination of vemurafenib and ML caused a synergistic effect on melanoma cells in vitro and inhibited in vivo tumor growth in a preclinical model, without causing mouse weight loss or genotoxicity. Our original research contributes to the landscape of pharmacological treatments for melanoma, providing MC4R antagonists as drugs that can be added to established therapies.

Discovery of a Potent Dual Inhibitor of Aromatase and Aldosterone Synthase.

Estrogen deficiency derived from inhibition of estrogen biosynthesis is a typical condition of postmenopausal women and breast cancer (BCs) patients undergoing antihormone therapy. The ensuing increase in aldosterone levels is considered to be the major cause for cardiovascular diseases (CVDs) affecting these patients. Since estrogen biosynthesis is regulated by aromatase (CYP19A1), and aldosterone biosynthesis is modulated by aldosterone synthase (CYP11B2), a dual inhibitor would allow the treatment of BC while reducing the cardiovascular risks typical of these patients. Moreover, this strategy would help overcome some of the disadvantages often observed in single-target or combination therapies. Following an in-depth analysis of a library of synthesized benzylimidazole derivatives, compound X21 was found to be a potent and selective dual inhibitor of aromatase and aldosterone synthase, with IC50 values of 2.3 and 29 nM, respectively. Remarkably, the compound showed high selectivity with respect to 11ß-hydroxylase (CYP11B1), as well as CYP3A4 and CYP1A2. When tested in cells, X21 showed potent antiproliferative activity against BC cell lines, particularly against the ER+ MCF-7 cells (IC50 of 0.26 ± 0.03 µM at 72 h), and a remarkable pro-apoptotic effect. In addition, the compound significantly inhibited mTOR phosphorylation at its IC50 concentration, thereby negatively modulating the PI3K/Akt/mTOR axis, which represents an escape for the dependency from ER signaling in BC cells. The compound was further investigated for cytotoxicity on normal cells and potential cardiotoxicity against hERG and Nav1.5 ion channels, demonstrating a safe biological profile. Overall, these assays demonstrated that the compound is potent and safe, thus constituting an excellent candidate for further evaluation.

Correction: Bocci et al. Remarkable Remission Rate and Long-Term Efficacy of Upfront Metronomic Chemotherapy in Elderly and Frail Patients, with Diffuse Large B-Cell Lymphoma. J. Clin. Med. 2022, 11, 7162.

In the original publication [...].

Remarkable Remission Rate and Long-Term Efficacy of Upfront Metronomic Chemotherapy in Elderly and Frail Patients, with Diffuse Large B-Cell Lymphoma.

The upfront treatment of very elderly and frail patients with diffuse large B-cell lymphoma (DLBCL) is still a matter of debate. Herein, we report results of the metronomic all-oral DEVEC [prednisolone/deltacortene®, vinorelbine (VNR), etoposide (ETO), cyclophosphamide] combined with i.v. rituximab (R). This schedule was administered as a first line therapy in 22 elderly/frail DLBCL subjects (median age = 84.5 years). In 17/22 (77%) patients, the Elderly-IPI-score was high. After a median follow-up of 24 months, 15 patients had died: seven (50%) for causes unrelated to DLBCL or its treatment, six (40%) for progression, and two (13%) for multiorgan failure. Six treatment-pertinent serious-adverse-events occurred. At the end of induction, 14/22 (64%) achieved complete remission; overall survival and event-free survival at 24 months were both 54% (95% CI = 32−72%), while the time to progression was 74% (95% CI = 48−88%). Furthermore, antiproliferative and proapoptotic assays were performed on DLBCL/OCI-LY3 cell-line using metronomic VNR and ETO and their combination. Both metronomic VNR and ETO had concentration-dependent antiproliferative (IC50 = 0.036 ± 0.01 nM and 7.9 ± 3.6 nM, respectively), and proapoptotic activities in DLBCL cells. Co-administration of the two drugs showed a strong synergism (combination index < 1 and dose reduction index > 1) against cell proliferation and survival. This low-dose schedule seems to compare favourably with intravenous-CHEMO protocols used in the same subset. Indeed, the high synergism shown by metronomic VRN+ETO in in vitro studies, explains the remarkable clinical responses and it allows significant dose reductions.

Predictive Power of Tissue and Circulating Biomarkers for the Severity of Biopsy-Validated Chronic Liver Diseases.

Background: Although liver biopsy remains the gold standard for the diagnosis and the monitoring of liver disease, non-invasive biomarkers have been recently suggested to predict liver disease severity, progression, and response to therapy. We investigated multiple tissue and circulating markers of angiogenesis in predicting the severity of biopsy-validated chronic liver diseases in patients with chronic hepatitis C virus (HCV) and in NAFLD/NASH patients. Methods: We studied samples from forty-six patients with HCV and/or NAFLD who underwent liver biopsy, liver ultrasonography, and liver stiffness measurement. Ishak and Brunt scores were calculated. Expression of selective genes and luminex analyses of 17 different circulating pro-angiogenic factors were performed. Results: The phenotype of NAFLD/NASH or HCV subjects was similar, except for insulin, which was expressed at higher levels in NAFLD/NASH patients. A Mann−Whitney test showed significant differences for the circulating levels of HB-EGF and for follistatin between HCV and NAFLD/NASH patients. In HCV patients, we found an inverse correlation between disease stage and BMP-9 and VEGF-A circulating levels, while in NASH/NAFLD direct correlations between stage and BMP-9 and VEGF-A circulating levels were noted. The K-means algorithm divided HCV and NASH/NAFLD patients in two clusters with significant differences between them. Logistic regression models showed a positive relationship with BMP-9 levels for NASH/NAFLD and with HB-EGF circulating concentrations for HCV. ROC analysis showed for BMP-9 > 1188 pg/mL a worse disease in NASH/NAFLD, whereas for HB-EGF < 61 pg/mL a higher severity of disease in HCV. Conclusion: Our data show that circulating biomarker profiles can identify the severity of chronic liver disease of NAFLD/NASH or HCV origin.

Early increase of plasma soluble VEGFR-2 is associated with clinical benefit from second-line treatment of paclitaxel and ramucirumab in advanced gastric cancer.

Ramucirumab plus paclitaxel is considered the standard of care in the second-line treatment of gastric carcinoma (GC). The aim of this study was to evaluate plasma vascular endothelial growth factor-A (VEGF-A), VEGF-D, and circulating soluble VEGF receptor-2 (sVEGFR-2) as possible markers of resistance or response to ramucirumab administered with paclitaxel in pretreated metastatic GC patients. Plasma samples were collected at different time points (on days 1 and 15 of the first 3 cycles, at best radiologic response and at disease progression). VEGF-A, VEGF-D and sVEGFR-2 were analysed by ELISA. Correlations of biomarker baseline levels or dynamic changes with outcome measures were assessed. Progression-free survival (PFS) was the primary endpoint of the study. Forty-one patients were enrolled. VEGF-A and VEGF-D, but not sVEGFR-2, values significantly increased during treatment compared to baseline (P < 0.001). A positive correlation between VEGF-A and sVEGFR-2 at cycle 2 was found (P=0.045). At univariate analysis, higher baseline levels of VEGF-A were associated with worse OS (P=0.015). Early increase of sVEGFR-2 levels after the first treatment cycle was the only factor associated with longer PFS (6.6 vs. 3.6 months, P=0.049) and OS (18.6 vs. 5.2 months, P=0.008). Significance of sVEGFR-2 early increase was retained at multivariate analysis for OS (HR 0.32; 95% CI 0.12-0.91; P=0.032). The reported results confirmed the prognostic role of baseline VEGF-A and, with the limitations of the limited sample size and the lack of a control arm, suggested that the early increase of sVEGFR-2 after 1 cycle of treatment could be a potential predictive biomarker of benefit from second-line ramucirumab plus paclitaxel in GC.

New antiproliferative agents derived from tricyclic 3,4-dihydrobenzo[4,5]imidazo[1,2-a][1,3,5]triazine scaffold: Synthesis and pharmacological effects.

A series of novel 3,4-dihydrobenzo[4,5]imidazo[1,2-a][1,3,5]triazine (BIT) derivatives were designed and synthesized. In vitro antiproliferative activity was detected toward two human colorectal adenocarcinoma cell lines (CaCo-2 and HT-29) and one human dermal microvascular endothelial cell line (HMVEC-d). The most active compounds, namely 2-4 and 8, were further investigated to clarify the mechanism behind their biological activity. Through immunofluorescence assay, we identified the target of these molecules to be the microtubule cytoskeleton with subsequent formation of dense microtubule accumulation, particularly at the periphery of the cancer cells, as observed in paclitaxel-treated cells. Overall, these results highlight BIT derivatives as robust and feasible candidates deserving to be further developed in the search for novel potent antiproliferative microtubule-targeting agents.

Old and New Systemic Immune-Inflammation Indexes Are Associated with Overall Survival of Glioblastoma Patients Treated with Radio-Chemotherapy.

Background. Systemic immunity and inflammation indexes (SI) derived from blood cells have gained increasing attention in clinical oncology as potential biomarkers that are associated with survival. Materials and methods. We tested 12 different SI using blood tests from patients with isocitrate dehydrogenase 1 and 2 wild-type glioblastomas, treated with radio-chemotherapy. The primary endpoint was their overall survival. Results. A total of 77 patients, comprising 43 males and 34 females, with a median age of 64 years (age range 26-84), who were treated between October 2010 and July 2020, were included in the present analysis (approved by a local ethics committee). In the univariate Cox regression analysis, all the indexes except two showed a statistically significant impact on OS. In the multivariate Cox regression analysis, neutrophil × platelet × leukocyte/(lymphocyte × monocyte) (NPW/LM) and neutrophil × platelet × monocyte/lymphocyte (NPM/L) maintained their statistically significant impact value. Conclusions. This univariate analysis confirms the potential of systemic inflammation indexes in patients with glioblastoma, while the multivariate analysis verifies the prognostic value of NPW/LM and NPM/L.

Association of plasma levetiracetam concentration, MGMT methylation and sex with survival of chemoradiotherapy-treated glioblastoma patients.

Glioblastoma multiforme (GBM) is an aggressive brain tumor, often occurring with seizures managed with antiepileptic drugs, such as levetiracetam (LEV). This study is aimed at associating progression-free survival (PFS) and overall survival (OS) of GBM patients with LEV plasma concentration, MGMT promoter methylation, and sex. In this retrospective, non-interventional, and explorative clinical study, GBM patients underwent surgery and/or radiotherapy and received LEV during adjuvant temozolomide (TMZ) treatment. A high-performance liquid chromatography with UV-detection was used for therapeutic drug monitoring of LEV plasma concentrations. Follow-up average drug concentration was related to patients' clinical characteristics and outcomes. Forty patients (42.5 % female; mean age=54.73 ± 11.70 years) were included, and GBM MGMT methylation status was assessed. All were treated with adjuvant TMZ, and LEV for seizure control. Patients harboring methylated MGMT promoter showed a longer median PFS (460 vs. 275 days, log-rank p < 0.001). The beneficial effect of MGMT promoter methylation was more evident for females (p < 0.001) and in patients with LEV concentration ≤ 20.6 µg/mL (562 days vs. 274.5 days, p = 0.032). Female patients also showed longer OS (1220 vs. 574 days, p = 0.03). Also, higher LEV concentration (>20.6 µg/mL) synergized with MGMT promoter methylation by extending the OS (1014 vs. 406 days of patients with no methylation and low LEV average concentration, p = 0.021). Beneficial effect of higher LEV plasma levels was more evident in males (p = 0.024). Plasma concentrations of LEV may support better outcomes for chemoradiotherapy when other positive prognostic factors are lacking and may promote overall survival by synergizing with MGMT promoter methylation and male sex.

A pharmacogenetic interaction analysis of bevacizumab with paclitaxel in advanced breast cancer patients.

To investigate pharmacogenetic interactions among VEGF-A, VEGFR-2, IL-8, HIF-1α, EPAS-1, and TSP-1 SNPs and their role on progression-free survival (PFS) in metastatic breast cancer (MBC) patients treated with bevacizumab plus first-line paclitaxel or with paclitaxel alone. Analyses were performed on germline DNA, and SNPs were investigated by real-time PCR technique. The multifactor dimensionality reduction (MDR) methodology was applied to investigate the interaction between SNPs. The present study was an explorative, ambidirectional cohort study: 307 patients from 11 Oncology Units were evaluated retrospectively from 2009 to 2016, then followed prospectively (NCT01935102). Two hundred and fifteen patients were treated with paclitaxel and bevacizumab, whereas 92 patients with paclitaxel alone. In the bevacizumab plus paclitaxel group, the MDR software provided two pharmacogenetic interaction profiles consisting of the combination between specific VEGF-A rs833061 and VEGFR-2 rs1870377 genotypes. Median PFS for favorable genetic profile was 16.8 vs. the 10.6 months of unfavorable genetic profile (p = 0.0011). Cox proportional hazards model showed an adjusted hazard ratio of 0.64 (95% CI, 0.5-0.9; p = 0.004). Median OS for the favorable genetic profile was 39.6 vs. 28 months of unfavorable genetic profile (p = 0.0103). Cox proportional hazards model revealed an adjusted hazard ratio of 0.71 (95% CI, 0.5-1.01; p = 0.058). In the 92 patients treated with paclitaxel alone, the results showed no effect of the favorable genetic profile, as compared to the unfavorable genetic profile, either on the PFS (p = 0.509) and on the OS (p = 0.732). The pharmacogenetic statistical interaction between VEGF-A rs833061 and VEGFR-2 rs1870377 genotypes may identify a population of bevacizumab-treated patients with a better PFS.

Antiangiogenic Drugs in NASH: Evidence of a Possible New Therapeutic Approach.

Non-alcoholic fatty liver disease is the most common liver disorder worldwide, and its progressive form non-alcoholic steatohepatitis (NASH) is a growing cause of liver cirrhosis and hepatocellular carcinoma (HCC). Lifestyle changes, which are capable of improving the prognosis, are hard to achieve, whereas a pharmacologic therapy able to combine efficacy and safety is still lacking. Looking at the pathophysiology of various liver diseases, such as NASH, fibrosis, cirrhosis, and HCC, the process of angiogenesis is a key mechanism influencing the disease progression. The relationship between the worsening of chronic liver disease and angiogenesis may suggest a possible use of drugs with antiangiogenic activity as a tool to stop or slow the progression of the disorder. In this review, we highlight the available preclinical data supporting a role of known antiangiogenic drugs (e.g., sorafenib), or phytotherapeutic compounds with multiple mechanism of actions, including also antiangiogenic activities (e.g., berberine), in the treatment of NASH.

Association of XRCC3 rs1799794 polymorphism with survival of glioblastoma multiforme patients treated with combined radio-chemotherapy.

This study reports the results of a monocentric prospective analysis conducted with the aim of evaluating the impact of XRCC1 rs25487, XRCC3 rs861539, XRCC3 rs1799794, RAD51 rs1801320 and GSTP-1 rs1695 single nucleotide polymorphisms (SNP) on patients with high-grade glioma treated with concomitant radio-chemotherapy. From October 2010 to August 2019, a total of 75 patients aged ≥18 years, with histological diagnosis of high-grade glioma, isocitrate dehydrogenase (IDH) 1/2 wild type and treated with radio-chemotherapy and sequential chemotherapy with temozolomide (TMZ) were prospectively recruited. The local ethic committee approved this study (Comitato Etico di Area Vasta Nord Ovest [CEAVNO]; protocol 3304/2011). After a median follow up of 25 months (range: 7-98 months), median progression-free survival (PFS) and overall survival (OS) were 11 months (CI95%: 8-14 months) and 18 months (CI95%: 15-21 months), respectively. In univariate and multivariate Cox regression analysis, a statistically significant association with PFS and OS was found with XRCC3 rs1799794 SNP. The study suggests that XRCC3 rs1799794 SNP can be associated with different PFS and OS in glioblastoma patients treated with radio-chemotherapy.

Active metronomic vinorelbine schedules decrease plasma interleukin-2 levels in mice with Lewis lung carcinoma.

The aim of our study was to investigate the effects of metronomic vinorelbine (mVNR) in a tumor model of Lewis Lung (LL) cancer in immunocompetent C57BL/6 mice, looking at the plasma levels of interleukin-2 (IL-2) and interleukin-8 (IL-8). mVNR caused a concentration-dependent antiproliferative effect in vitro on LL/2 cells. The in vivo experiment showed the significant antitumor effects of mVNR at the dose of 4 mg/Kg and 5 mg/Kg, 3 times/week, and the significant dose-dependent decrease of IL-2 concentrations in plasma samples. Conversely, such an effect was not observed for IL-8. A significant decrease in microvessel density was also found at both the active mVNR doses. In conclusion, our study confirmed the activity of mVNR in an immunocompetent model of lung carcinoma and suggest multiple mechanisms of action, including the modulation of IL-2 levels.

All-oral metronomic DEVEC schedule in elderly patients with peripheral T cell lymphoma.

PURPOSE: Peripheral T cell lymphomas (PTCLs) have an overall poor prognosis. Indeed, registry data in elderly patients show that the median progression-free survival (mPFS) following first- and second-line therapies are only 6.7 and 3.1 months, respectively. The aim of the study is to show the activity of metronomic chemotherapy, a regular administration of low chemotherapeutic drug doses allowing a favourable toxicity profile, on elderly PTCL patients. METHODS: We report a series of 17 PTCL patients, treated with the all-oral metronomic schedule DEVEC (prednisolone-etoposide-vinorelbine-cyclophosphamide) in four Italian centres. Patients 5/17 (29.4%) were treatment-naïve (naïve) and 12/17 (70.6%) were relapsed-refractory (RR), respectively. The median age was 83 years (range 71-87) and 71.5 years (range 56-85) for naïve and RR, respectively. In vitro activity of metronomic vinorelbine (VNR), etoposide (ETO) and their concomitant combination on HH, a PTCL cell line, was also assessed. RESULTS: Histology: PTCL-not-otherwise-specified = 12; angioimmunoblastic = 2; NK/T nasal type = 1; adult-type leukaemia lymphoma = 1, transformed Mycosis Fungoides = 1. The overall response rate was 80 and 58% in naïve and RR, respectively; whereas the PFS was 20 in naïve (95% CI 0-43) and 11 months (95% CI 4.2-17.8) in RR. The occurrence of relevant adverse events was 23.5%, which was managed with ETO dose reduction. In vitro experiments showed that both metronomic VNR and ETO caused a significant inhibitory activity on HH cells and a strong synergism when administered concomitantly. CONCLUSION: All-oral DEVEC showed an encouraging activity and acceptable toxicity. This schedule deserves further studies in elderly PTCL also for assessing combinations with targeted drugs.

Synergistic activity of linifanib and irinotecan increases the survival of mice bearing orthotopically implanted human anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid cancer, and novel combined therapies are urgently needed to prolong patient survival. No data are currently available on the preclinical activity of the combination of linifanib, a CSF-1R inhibitor, and irinotecan in ATC. The aim of the study was to evaluate the in vitro and in vivo activity of linifanib plus irinotecan. Proliferation and apoptosis assays were performed on 8305C and 8505C human ATC cell lines exposed to SN-38, the active metabolite of irinotecan, linifanib alone, and their concomitant combination. Synergism was evaluated by the combination index method. Quantification of pospho-CSF-1R levels was performed by ELISA. In vivo ATC orthotopic xenografts were treated with the single drugs, or their combination, to evaluate their impact on survival. Histology and immunohistochemistry were performed on ATC tissue samples. Both SN-38 and linifanib inhibited in vitro the proliferation of 8305C and 8505C cells in a concentration-dependent manner, whereas their concomitant treatment revealed a strong synergism in the ATC cells. A significant pro-apoptotic activity was found in both ATC cell lines treated with linifanib alone and in combination with SN-38. Moreover, linifanib significantly decreased the levels of phospho-CSF-1R after 24 h and 72 h in both 8505C and 8305C cells, and this was also observed with the concomitant administration of SN-38. In vivo, the combination of linifanib and irinotecan produced a greater survival result than either monotherapy, and resulted in a significant higher median survival. In some of the mice the combination produced a complete response with a macroscopic disappearance of the disease, as confirmed by histology. In conclusion, the synergistic ATC antitumor activity of linifanib/irinotecan combination significantly increased the survival of ATC affected mice and induced some complete responses, suggesting a potential role of this schedule in ATC patient's treatment.

Pharmacological effects of vinorelbine in combination with lenvatinib in anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is a rare neoplasia with a poor prognosis. Proliferation and apoptosis assays were performed on ATC cell lines (8305C, 8505C) exposed to vinorelbine, lenvatinib, as well as to concomitant combinations. ABCB1, ABCG2 and CSF-1 mRNA expression was evaluated by real time PCR. The relative levels of pospho Akt were investigated as part of a human phospho-kinase array analysis, and CSF-1 and VEGFR-2 protein levels were measured by ELISA. The intracellular concentration of lenvatinib in ATC cells was measured by combined reversed-phase liquid chromatography-tandem mass spectrometry. An ATC subcutaneous xenograft tumor model in nude mice was treated with vinorelbine, lenvatinib, or vinorelbine plus lenvatinib. After treatment with vinorelbine, lenvatinib, a significant antiproliferative effect in ATC cell lines was observed. The concomitant treatment of vinorelbine and lenvatinib revealed synergism for all the fractions of affected cells. A decrease in ABCB1 expression was reported in both ATC cell lines treated with the lenvatinib plus vinorelbine combination, as was an increase in the intracellular concentration of lenvatinib. The combination caused a decrease in Akt, GSK3α/ß, PRAS40 and Src phosphorylation, and in both CSF-1 mRNA and protein levels. In the subcutaneous tumor model, the combination reduced the tumor volume during the treatment period. Our results establish the synergistic ATC antitumor activity of a vinorelbine and lenvatinib combination.

Preclinical and clinical combination therapies in the treatment of anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid cancer, and novel therapies are urgently needed to prolong patient survival and improve clinical outcomes. Very few scientific reviews have examined the literature on combination therapies with the goal of describing the available preclinical and clinical data and suggesting future clinical combination treatment schedules. The present review focuses on preclinical and clinical studies of drug combination therapies in ATC. The relevant literature from PubMed and Scopus was reviewed in this article; the ClinicalTrials.gov database was searched for clinical trials not yet published. Recent data from preclinical models strongly support the idea that combination treatments that utilize drugs from different antineoplastic classes have synergistic antitumour activity in ATC. However, rapid translation of these therapies into the clinic is impeded by the difficulty in recruiting enough patients for randomized clinical trials. Although promising results have been obtained in preclinical studies, additional clinical research is required to elucidate the efficacy of combination treatments for clinical practice.

Pharmacological effects of the simultaneous and sequential combinations of trifluridine/tipiracil (TAS-102) and 5-fluorouracil in fluoropyrimidine-sensitive colon cancer cells.

The aim of this study was to investigate possible synergistic effects in vitro of trifluridine/tipiracil (TAS-102) and 5-fluoruracil (5-FU) on fluoropyrimidine-sensitive colon cancer cell lines of different mutational status in order to build a rational basis for the future use of this combination therapy in adjuvant settings or as a first-line treatment for metastatic disease. Proliferation assays were performed on HT-29 (B-raf mutated), SW-620 (ras mutated), and Caco-2 (wild type) colon cancer cell lines exposed to 120-h treatments of 5-FU, TAS-102 and their different combination schedules (simultaneous, sequential and reverse) at equimolar and non-equimolar ratios. The synergistic, additive and antagonistic effects of 5-FU and TAS-102 were determined by the combination index (CI) and dose reduction index (DRI). Our preclinical in vitro results may suggest an apparently counterintuitive but strongly synergistic combination of 5-FU and TAS-102 in fluoropyrimidine-sensitive colon cancer cells allowing a marked theoretical reduction in the administered doses of both drugs. In particular, this association seems to be highly effective in wild-type colon cancer cells, both in sequential and simultaneous schedules. Together, these data may build a rational basis for the future use of TAS-102 combined with 5-FU in adjuvant settings, or as a first-line treatment for metastatic disease.