Preliminary studies of a novel oral fluoropyrimidine carbamate: capecitabine

Spotlight on capecitabine for the treatment of unresectable or metastatic carcinoma of various origin: A retrospective study of 25 dogs

Capecitabine, the oral prodrug of 5-fluorouracil, is indicated in people to treat various malignant epithelial cancers. In dogs, capecitabine has not been extensively evaluated. The aim of this retrospective study was to investigate toxicity and preliminary efficacy of single agent capecitabine in dogs with advanced malignant epithelial cancers of any site, for which no effective therapy existed, conventional treatment failed or was declined. Capecitabine was administered orally at 750 mg/m2 from day 1 to 14, followed by 1-week rest period, given as 3-week cycles. Safety evaluation was performed after 2 cycles, and every 2-3 cycles thereafter. Tumour response was determined every 2-3 cycles. Twenty-five dogs with hepatocellular carcinoma (n = 6), lung papillary carcinoma (n = 4), anal sac adenocarcinoma (n = 3), colic adenocarcinoma (n = 2), and other individually represented epithelial cancers (n = 10) were included. Dogs received a median of 4 cycles (range, 2-43) for a median of 84 days (range, 42-913). Toxicity occurred in 17 (68.0%) dogs; the most frequent adverse events were gastrointestinal, with the majority being self-resolving and of mild grade. Of the 22 dogs with macroscopic disease, 3 (13.6%) achieved partial remission, 16 (72.7%) were stable and 3 (13.6%) progressed; overall clinical benefit rate was 86.4%. Median progression-free interval was 93 days (95% CI 42-154; range, 1-521) and median tumour-specific survival was 273 days (95% CI 116-482; range 45-913). These findings suggest that capecitabine is an attractive option for the treatment of several types of carcinomas in dogs. Prospective studies are warranted to optimize the scheduling of capecitabine and confirm its efficacy.

A pilot study investigating plasma pharmacokinetics and tolerance of oral capecitabine in carcinoma-bearing dogs

BACKGROUND

Capecitabine is an oral prodrug of the active metabolite 5-fluorouracil, which has been used effectively in human colorectal, head and neck, and mammary carcinomas. Capecitabine has several properties that make it an attractive treatment option for dogs: (i) it is relatively inexpensive, (ii) it has a short half-life in humans, allowing for rapid plasma concentration changes to be achieved with dosage adjustments, (iii) it is effective for treating carcinomas in humans, for which there are no widely-effective oral chemotherapy options in dogs, and (iv) it is thought to preferentially target cancer cells due to different expression of thymidine phosphorylase, thereby decreasing the risk of off-target side effects. However, capecitabine has not been widely explored as a chemotherapy agent for dogs. The goal of this study was to determine the plasma disposition of capecitabine in dogs following a single oral dose and to document any adverse events associated with capecitabine administration over the course of 5 weeks.

RESULTS

Capecitabine was well tolerated throughout the 5-week study period when administered to 5 dogs with naturally occurring carcinomas at 750 mg/m[Formula: see text] by mouth once daily for 14 consecutive days in a 3-week cycle. No dogs withdrew from the study due to adverse events or other causes. The median AUC[Formula: see text] was 890 h[Formula: see text]ng/ml (range 750-1100 h[Formula: see text]ng/ml); however, the maximum blood concentration and time to reach that concentration of capecitabine was highly variable after a single dose.

CONCLUSIONS

Capecitabine appears well-tolerated as an oral chemotherapy agent for dogs with carcinomas, although individualized dosing may be necessary, and further studies are warranted.

A polymorphism in ABCA2 is associated with neutropenia induced by capecitabine in Japanese patients with colorectal cancer

PURPOSE

Capecitabine is a prodrug that converts to 5-fluorouracil (5-FU) in three steps. A previous study showed that ABCA2 rs2271862 (C > T) and ABCG5 rs6720173 were associated with increased clearance of 5-FU and 5'-deoxy-5-fluorouridine, respectively, in Spanish patients with colorectal cancer (CRC) (Br J Clin Pharmacol 2021) and reported that ABCA2 rs2271862 was associated with decreased risk of capecitabine-induced neutropenia. Other studies have reported that ABCB1 rs1128503, rs2032592, and rs1045642 were associated with capecitabine-induced toxicity in Spanish CRC patients (Oncotarget 2015, Phamacogenomics 2010). Here, we prospectively examined the effects of ABC transporter genes polymorphisms on capecitabine pharmacokinetics and toxicity.

METHODS

We enrolled patients with postoperative CRC treated with adjuvant capecitabine plus oxaliplatin (CapeOX) and patients with metastatic CRC receiving CapeOX. Pharmacokinetic analysis of the first capecitabine dose (1000 mg/m2) was performed on day 1. We analyzed plasma concentrations of capecitabine and its three metabolites by high-performance liquid chromatography and ABC transporter genes polymorphisms using direct sequencing.

RESULTS

Patients with ABCA2 rs2271862 T/T genotype had significantly lower area under the plasma concentration-time curve of capecitabine, but not of its metabolites, which were divided by the dose of the parent drug, than patients with C/C or C/T genotype (P = 0.0238). Frequency of ≥ grade 2 neutropenia was significantly lower in patients with ABCA2 rs2271862 T/T genotype (P = 0.00915). Polymorphisms in ABCG5 and ABCB1 were not associated with capecitabine pharmacokinetics and toxicity.

CONCLUSIONS

We found that ABCA2 polymorphism was significantly associated with systemic exposure to capecitabine and capecitabine-induced neutropenia in Japanese patients with CRC.

Metronomic Chemotherapy

Simple Summary

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

Abstract

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

Capecitabine in treating patients with advanced, persistent, or recurrent cervical cancer: an active and safe option?

Introduction: Advanced, persistent or recurrent cervical cancer in patients not amenable to curative surgery or radiotherapy predicts a dismal prognosis. Systemic chemotherapy based on paclitaxel/cisplatin ± bevacizumab is the current standard of care. However, once progression occurs, the possibility of alternative treatment options is very limited.Areas covered: The usefulness of capecitabine has been well-established against several cancer types, including head and neck, breast, and colorectal cancer. This review covers current literature evidence on the clinical efficacy and safety of capecitabine in cervical cancer treatment, either as monotherapy or combined with other agents or chemo-radiotherapy.Expert opinion: Recent clinical data, albeit scant, suggested a promising role for capecitabine both as monotherapy in patients with platinum-resistant cervical cancer and in combination with cisplatin in chemotherapy-naïve patients with metastatic or recurrent cervical cancer. In our opinion, capecitabine, especially in combination regimens, could represent a valid treatment option and further research is warranted to better understand its effectiveness in these challenging patients.

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

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COVID 19 pandemic represents an emergency for public health services.

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

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Oral treatments and de-escalation strategies are encouraged.

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

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

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

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

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

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

Correlation Between the Metabolic Conversion of a Capecitabine Metabolite, 5'-Deoxy-5-fluorocytidine, and Creatinine Clearance

AIM

Capecitabine is a prodrug that is metabolized to its active form, 5-fluorouracil (5-FU), in three enzymatic steps. This prospective pharmacokinetic study evaluated cytidine deaminase (CDA) activity, the second drug-metabolizing enzyme that generates 5'-deoxy-5-fluorouridine (5'-DFUR) from 5'-deoxy-5-fluorocytidine (5'-DFCR), as well as creatinine clearance (CLcr).

PATIENTS AND METHODS

Patients with colorectal cancer who received capecitabine plus oxaliplatin were selected. Pharmacokinetics of capecitabine and its metabolites, and CDA activity in plasma were analyzed.

RESULTS

Eighteen patients were examined. The area under the plasma concentration-time curve (AUC) of 5'-DFUR showed a significant inverse correlation with CLcr (p=0.003). The metabolic ratio, i.e. the ratios of the AUC of 5'-DFUR plus that of 5-FU to the AUC of 5'-DFCR, significantly increased when CLcr decreased (p=0.001) but did not depend on plasma CDA activity.

CONCLUSION

Metabolism of 5'-DFCR to form 5'-DFUR increased as CLcr decreased but the mechanism remains unknown.

Phase I pharmacological study of continuous chronomodulated capecitabine treatment

Purpose

Capecitabine is an oral pre-pro-drug of the anti-cancer drug 5-fluorouracil (5-FU). The biological activity of the 5-FU degrading enzyme, dihydropyrimidine dehydrogenase (DPD), and the target enzyme thymidylate synthase (TS), are subject to circadian rhythmicity in healthy volunteers. The aim of this study was to determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), safety, pharmacokinetics (PK) and pharmacodynamics (PD) of capecitabine therapy adapted to this circadian rhythm (chronomodulated therapy).

Methods

Patients aged ≥18 years with advanced solid tumours potentially benefitting from capecitabine therapy were enrolled. A classical dose escalation 3 + 3 design was applied. Capecitabine was administered daily without interruptions. The daily dose was divided in morning and evening doses that were administered at 9:00 h and 24:00 h, respectively. The ratio of the morning to the evening dose was 3:5 (morning: evening). PK and PD were examined on treatment days 7 and 8.

Results

A total of 25 patients were enrolled. The MTD of continuous chronomodulated capecitabine therapy was established at 750/1250 mg/m²/day, and was generally well tolerated. Circadian rhythmicity in the plasma PK of capecitabine, dFCR, dFUR and 5-FU was not demonstrated. TS activity was induced and DPD activity demonstrated circadian rhythmicity during capecitabine treatment.

Conclusion

The MTD of continuous chronomodulated capecitabine treatment allows for a 20% higher dose intensity compared to the approved regimen (1250 mg/m² bi-daily on day 1–14 of every 21-day cycle). Chronomodulated treatment with capecitabine is promising and could lead to improved tolerability and efficacy of capecitabine.

Electronic supplementary material

The online version of this article (10.1007/s11095-020-02828-6) contains supplementary material, which is available to authorized users.

Capecitabine versus 5-fluorouracil in neoadjuvant chemoradiotherapy of locally advanced rectal cancer: A meta-analysis

BACKGROUND

The differences in efficacy between capecitabine and 5-fuorouracil (5-FU) in neoadjuvant chemoradiotherapy (CRT) of locally advanced rectal cancer (LARC) are not well recognized. We performed this meta-analysis to analyze the effect of capecitabine and 5-FU on neoadjuvant CRT to more accurately understand the differences between the 2 drugs.

METHODS

MEDLINE, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Database were performed to identify all published studies investigating the efficacy of capecitabine in neoadjuvant CRT of LARC versus 5-FU before August, 2017. Primary endpoint was the odds ratio (OR) for improving pathological complete response (pCR) rate of patients with LARC. Secondary endpoints were the ORs of efficiency for downstaging tumor and increasing R0 resection in patients with LARC. Safety analyses were also performed. The OR was the principal measurement of effect, which was calculated as capecitabine group versus 5-FU group, and was presented as a point estimate with 95% confidence intervals (CIs). All calculations and statistical tests were performed using RevMan 5.3 software.

RESULTS

In all, 2916 patients with LARC enrolled in the 10 studies were divided into capecitabine group (n = 1451) and 5-FU group (n = 1465). The meta-analysis showed that capecitabine improved pCR (OR 1.34, 95% CI 1.10-1.63), and R0 resection rate (OR 1.92, 95% CI 1.10-3.36). There were no statistically significant differences either in overall downstaging rate (OR 1.31, 95% CI 0.79-2.16) or in the tumor downstaging rate (OR 1.24, 95% CI 0.79-1.92), but there was a significant difference of the nodal downstaging rate between the 2 groups (OR 1.68, 95% CI 1.11-2.54). There was no statistically significant difference in sphincter preservation rate between the 2 groups (OR 1.36, 95% CI 0.96-1.92). No obvious safety concerns about mortality and complications were raised in these studies. There were no statistically significant differences in 3-year disease-free-survival (OR 1.29, 95% CI 0.75-2.20), and in grade 3 to 4 acute toxicity during CRT (OR 0.63, 95% CI 0.31-1.30).

CONCLUSIONS

Compared with 5-FU-based neoadjuvant CRT, capecitabine-based neoadjuvant CRT can safely improve pCR, nodal down-staging, ad R0 resection of patients with LARC.

Floating molecularly imprinted polymers based on liquid crystalline and polyhedral oligomeric silsesquioxanes for capecitabine sustained release

Molecularly imprinted polymers (MIPs) have drawn extensive attention as carriers on drug delivery. However, most of MIPs suffer from insufficient drug loading capacity, burst release of drugs and/or low bioavailability. To solve the issues, this study designed an imprinted material with superior floating nature for oral drug delivery system of capecitabine (CAP) rationally. The MIPs was synthesized in the presence of 4-methylphenyl dicyclohexyl ethylene (liquid crystalline, LC) and polyhedral oligomeric silsesquioxanes (POSS) via polymerization reaction. The LC-POSS MIPs had extended release of the template molecules over 13.4 h with entrapment efficiency of 20.53%, diffusion coefficient of 2.83 × 10^-11 cm² s^-1, and diffusion exponent of 0.84. Pharmacokinetic studies further revealed the prolong release and high relative bioavailability of CAP in vivo of rats, showing the effective floating effect of the LC-POSS MIPs. The in vivo images revealed visually that the gastroretentive time of the LC-POSS MIPs was longer than non-LC-POSS imprinted polymers. The physical characteristics of the polymers were also characterized by nitrogen adsorption experiment, scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetry analysis. As a conclusion, the LC-POSS MIPs can be used as an eligible CAP carrier and might hold great potential in clinical applications for sustained release drug.

Development and validation of a quantitative method for thymidine phosphorylase activity in peripheral blood mononuclear cells

The enzyme thymidine phosphorylase (TP) is important for activation of capecitabine and 5-fluorouracil. Assessment of TP phenotype might be suitable for identification of patients at risk of fluoropyrimidine-induced toxicity. In this paper, we describe the development and validation an assay for TP activity in peripheral blood mononuclear cells (PBMCs). The assay was based on ex vivo conversion of the TP substrate thymidine to thymine. The amount of thymine formed was determined by high-performance liquid chromatography - ultraviolet detection (HPLC-UV) with 5-bromouracil as internal standard. Lymphocytes and monocytes were purified from isolated PBMCs to examine cell-specific TP activity. TP activity in PBMCs demonstrated Michaelis-Menten kinetics. The lower limit of quantification was 2.3 µg PBMC protein and assay linearity was demonstrated up to 22.7 µg PBMC protein. Within-day and between-day precisions were ≤9.2% and ≤6.0%, respectively. Adequate stability TP activity was demonstrated after long-term storage of PBMC dry pellets and lysates at -80 °C. In monocytes, TP activity was approximately 3 times higher than in lymphocytes. Clinical applicability was demonstrated in samples that were collected from five cancer patients. A simple, precise and sensitive HPLC-UV assay for quantification of TP activity in PBMCs was developed that can be applied for clinical research.

Phase Ib trial combining capecitabine, erlotinib and bevacizumab in pancreatic adenocarcinoma - REBECA trial

Background Purpose of this phase Ib trial was to establish the maximum tolerable dose (MTD) of capecitabine and to escalate the dosages of erlotinib and bevacizumab to determine the recommended phase II dose (RP2D) in patients with advanced/metastatic pancreatic adenocarcinoma not pretreated for metastatic disease. Methods Starting doses were capecitabine 500 mg/m² bid orally continuously, erlotinib 100 mg orally daily, and bevacizumab 5 mg/kg intravenously q 2 weeks. Dose escalation was performed according to a 3 + 3 design for capecitabine until MTD, for erlotinib and bevacizumab until the maximum doses registered by applying a substance-related, toxicity-based scheme accompanied by pharmacokinetic analysis. Circulating tumor cells (CTCs) were determined pretherapeutically by immunohistochemical identification after enrichment with immunomagnetic separation. Results Thirty patients were evaluable at six dose levels. 900 mg/m² bid were determined as MTD for capecitabine based on dose-limiting toxicities: cutaneous in two patients and vascular in another. The most severe (Grade (G)3/4) drug-related treatment-emergent adverse events (toxicities) belonged to the categories gastrointestinal, vascular, cutaneous, cardiovascular, metabolic/nutritional or hematological. G3 toxicities occurred in 14 (47%), G3 + G4 in a single (3%) patient. 2 out of 28 patients (7%) exerted partial response, 17 (61%) stable disease. Pharmacokinetic evaluation revealed lack of drug-drug interaction between capecitabine and erlotinib and their metabolites. Presence of CTCs was associated with shorter progression-free survival (p = 0.009). Conclusions The study met the primary objective. RP2D was capecitabine 800 mg/m² bid continuously, erlotinib 150 mg daily, and bevacizumab 10 mg/kg q 2 weeks. The regimen could be applied safely, but demonstrated limited efficacy.

Thymidine phosphorylase: the unforeseen driver in colorectal cancer treatment?

5-Fluorouracil- and leucovorin-based chemotherapy regimens are the backbone of colorectal cancer treatment. The addition of oxaliplatin, irinotecan and monoclonal antibodies to this backbone has largely improved clinical outcomes, but has also led to new questions, with conflicting data frequently reported in studies. Thymidine phosphorylase (TP) is a nucleoside-metabolizing enzyme involved in 5-fluorouracil pharmacokinetics, as well as inflammatory responses, neoangiogenesis and apoptosis. TP expression is regulated by hypoxia, inflammatory cytokines and antitumoral agents. We hypothesize that TP could be the unforeseen driver in the conflicting data observed with different regimens commonly used in colorectal cancer treatment. Greater comprehension of the role of this enzyme in tumor progression and pyrimidine metabolism may lead to more accurate, patient-tailored therapy.

Acute Cardiotoxicity during Capecitabine Treatment: A Case Report

Capecitabine (Xeloda®, Roche, Monza), a fluoropyrimidine carbamate, is an orally administered drug that delivers fluorouracil (5-FU) selectively to the tumor. The drug has demonstrated activity in metastatic breast cancer, pancreatic cancer and colorectal cancer.

In this case report the authors describe an unusually and reversible cardiac side effect which occurs to 39-year-old patient treated with capecitabine 2000 mg/m2/day for advanced gastric cancer.

It is important to note that the safety data from clinical trials indicate that capecitabine has a toxicity profile typical of infused fluoropyrimidines. However, none of the studies described cardiac side effects.

Radiotherapy and Oral Capecitabine in the Preoperative Treatment of Patients with Rectal Cancer: Rationale, Preliminary Results and Perspectives

Preoperative radiotherapy alone or combined with chemotherapy increases the chances of tumor downstaging and down-sizing and facilitates sphincter-sparing surgical procedures, thereby improving survival and quality of life. Though several innovative agents are being investigated in combination with radiotherapy, 5-fluorouracil in continuous infusion remains the common schedule used in the preoperative chemoradiation setting. However, the protracted venous infusion of 5-fluorouracil requires specialized pumps and long-term venous access, which makes patients susceptible to infections or thrombosis. To overcome the 5-fluorouracil infusion-related problems, oral 5-fluorouracil precursors and inhibitors of 5-fluorouracil degradation have been developed and explored. These include oral fluoropyrimidines such as tegafur (ftora-fur), uracil plus tegafur (UFT), S-1, eniluracil and the oral carbamate capecitabine. Phase I trials have demonstrated the feasibility of the capecitabine-radiotherapy combination with respect to the bolus or infusion 5-fluorouracil-radiation approach and have defined the optimal dose of capecitabine during radiotherapy (825 mg/m2/day through a bid administration). Severe hand-foot syndrome occurred in 7-15% of patients, representing the most commonly observed toxicity. It is noteworthy that severe diarrhea with capecitabine during radiotherapy was not common. Leukopenia frequently occurred but was mild and reversible. Phase II trials, although limited in number, have evidenced a high probability of pathological complete response (up to 31%) with capecitabine and radiation, with an increased probability of sphincter-sparing surgical procedures. Although it is too early to assess whether oral capecitabine will be able to replace iv 5-fluorouracil in combination with preoperative radiotherapy, the NSABP will address this question in a large randomized trial. Finally, phase I-II trials evaluating escalating doses of capecitabine associated with oxaliplatin or irinotecan with radiotherapy are being carried out to assess the maximum-dose tolerance and efficacy in the preoperative setting. It is likely that these new chemoradiation associations might increase rectal cancer clearance, hopefully without increasing toxicity.

Capecitabine: Indications and Future Perspectives in the Treatment of Metastatic Colorectal and Breast Cancer

Fluoropyrimidines remain the most important drugs in the treatment of breast and colorectal carcinoma, but response rates and survival time have been disappointing. Optimal administration is by continuous intravenous infusion, which makes it cumbersome to use and compromises patient independence. Recently, a number of new agents, including fluorouracil prodrugs and selective dihydropyrimidine dehydrogenase inhibitors, have been studied, with promising results. Capecitabine is the first in a new class of fluoropyrimidines. It is an oral, tumor-activated anticancer drug whose activity mimics that of continuously infused 5-fluorouracil. Capecitabine circumvents dihydropyrimidine dehydrogenase catabolism and appears to be at least as active against metastatic colorectal and breast cancer as conventionally administered intravenous 5-fluorouracil, with significantly less toxicity, an improved quality of life, and lesser cost. Capecitabine may ultimately provide enhanced antitumor activity to fluorouracil-containing regimes for advanced colorectal and breast cancer.

Human Thymidylate Synthase Inhibitors Halting Ovarian Cancer Growth

Human thymidylate synthase (hTS) has an important role in DNA biosynthesis, thus it is essential for cell survival. TS is involved in the folate pathways, specifically in the de novo pyrimidine biosynthesis. Structure and functions are intimately correlated, account for cellular activity and, in a broader view, with in vivo mechanisms. hTS is a target for anticancer agents, some of which are clinical drugs. The understanding of the detailed mechanism of TS inhibition by currently used drugs and of the interaction with the mechanism of action of other anticancer agents can suggest new perspective of TS inhibition able to improve the anticancer effect and to overcome drug resistance. TS-targeting drugs in therapy today are inhibitors that bind at the active site and that mostly resemble the substrates. Nonsubstrate analogs offer an opportunity for allosteric binding and novel mode of inhibition in the cancer cells. This chapter illustrates the relationship among the large number of hTS actions at molecular and clinical levels, its role as a target for ovarian cancer therapy, in particular in cases of overexpression of hTS and other folate proteins such as those induced by platinum drug treatments, and address the potential combination of TS inhibitors with other suitable anticancer agents.

Metronomic chemotherapy in metastatic colorectal cancer

Overall survival and quality of life of patients with metastatic colorectal cancer (mCRC) have improved due to the development of standard systemic treatment. However, many patients are still suffering from the eventual progression of cancer, treatment-related toxicities, and the economic burden of new drugs. Salvage or maintenance therapy, which consistently controls or stabilizes tumor progression without debilitating quality of life, is required. Recently, metronomic capecitabine maintenance therapy after disease control using conventional chemotherapy with maximal tolerated doses has demonstrated beneficial results in a phase III trial. Metronomic chemotherapy has been known to control tumors through antiangiogenesis and immunomodulation as well as a direct effect on tumor-initiating cells. It has the characteristics of being minimally toxic, inexpensive, and durable for maintaining disease stabilization. Therefore, patients with mCRC, who tend to be elderly and frail and have been previously treated, might be suitable for metronomic therapeutic strategies. Furthermore, antiangiogenic therapy has been an important component in treating mCRC, but the schedules and doses of metronomic chemotherapy have not yet been established. Here we review translational and clinical research on metronomic chemotherapy in colorectal cancer (CRC).

Capecitabine in Combination with Docetaxel in First Line in HER2-Negative Metastatic Breast Cancer: an Observational Study

Due to the limited experience with capecitabine plus docetaxel (XT) combination in the first-line treatment of metastatic breast cancer in Hungary, the main objective of the study was to analyze the effectiveness and tolerability of XT therapy. A prospective, open-label, non-randomized, single-arm, multicenter, observational study was designed. All female patients were eligible whose metastatic breast cancer could be treated with the XT protocol according to the summary of product characteristics of the drugs. The median progression free survival was 9.9 ± 3.0 months. Time to treatment failure was 4.6 ± 5.1 months on average. The overall response rate was 28.9 %, the clinical benefit rate was 73.3 %. The treatment was discontinued in 35.6 % of patients due to disease progression and in 20.0 % due to adverse events (AE). 33 patients with a total of 73 AEs have been reported, and 13 of them had serious adverse events (SAE). The efficacy and the safety profile of XT chemotherapy proven in the study are consistent with the results demonstrated in randomized trials. First-line XT chemotherapy effectively improves the PFS in metastatic breast cancer.

Effects of capecitabine treatment on the uptake of thymidine analogs using exploratory PET imaging agents: 18F-FAU, 18F-FMAU, and 18F-FLT

Background

A principal goal for the use of positron emission tomography (PET) in oncology is for real-time evaluation of tumor response to chemotherapy. Given that many contemporary anti-neoplastic agents function by impairing cellular proliferation, it is of interest to develop imaging modalities to monitor these pathways. Here we examined the effect of capecitabine on the uptake of thymidine analogs used with PET: 3’-deoxy-3’-[¹⁸F]fluorothymidine (¹⁸F-FLT), 1-(2’-deoxy-2’-[¹⁸F]fluoro-β-D-arabinofuranosyl) thymidine (¹⁸F-FMAU), and 1-(2’-deoxy-2’-[¹⁸F]fluoro-β-D-arabinofuranosyl) uracil (¹⁸F-FAU) in patients with advanced cancer.

Methods

Fifteen patients were imaged, five with each imaging agent. Patients had been previously diagnosed with breast, colorectal, gastric, and esophageal cancers and had not received therapy for at least 4 weeks prior to the first scan, and had not been treated with any prior fluoropyrimidines. Subjects were imaged within a week before the start of capecitabine and on the second day of treatment, after the third dose of capecitabine. Tracer uptake was quantified by mean standard uptake value (SUV_mean) and using kinetic analysis.

Results

Patients imaged with ¹⁸F-FLT showed variable changes in retention and two patients exhibited an increase in SUV_mean of 172.3 and 89.9 %, while the other patients had changes ranging from +19.4 to -25.4 %. The average change in ¹⁸F-FMAU retention was 0.2 % (range -24.4 to 23.1) and ¹⁸F-FAU was -10.2 % (range -40.3 to 19.2). Observed changes correlated strongly with SUV_max but not kinetic measurements.

Conclusions

This pilot study demonstrates that patients treated with capecitabine can produce a marked increase in ¹⁸F-FLT retention in some patients, which will require further study to determine if this flare is predictive of therapeutic response. ¹⁸F-FAU and ¹⁸F-FMAU showed little change, on average, after treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0092-2) contains supplementary material, which is available to authorized users.

Capecitabine: a novel, orally administered, tumour-activated treatment for breast cancer

Objective. To provide a comprehensive review of the preclinical and clinical pharmacology and toxicology of the fluoropyrimidine, capecitabine, with particular reference to its use in metastatic breast cancer.

Data Sources. A MEDLINE search was conducted using the term ‘capecitabine’ for the period 1995 -2001. The reference lists from retrieved articles were reviewed and other relevant papers identified. The abstract books from the annual meetings of the American Society of Clinical and Oncology and the European Society of Medical Oncology were also reviewed.

Data Extraction. The aim of the review was to be comprehensive and descriptive. All studies containing information deemed to be of interest were reviewed by the author; none was excluded on grounds of quality.

Data Summary. Capecitabine is a prodrug of the widely used cytotoxic agent 5-fluorouracil (5-FU). Unlike 5-FU, it is extensively and reliably absorbed after oral administration and does not require folinate (FA) potentiation. The activation of capecitabine is a three-step enzymatic process. The final activating enzyme - thymidine phosphorylase - is found in unusually high concentrations in many solid tumours including breast cancers, resulting in preferential delivery of 5-FU to tumour tissues, and suggesting a greater potential for selective cytotoxicity than is seen with 5-FU.

Capecitabine has been examined both alone and in combination with a variety of cytotoxic drugs in the treatment of metastatic breast cancer. To date, clinical evidence supports the use of capecitabine monotherapy in patients relapsing after prior treatment with anthracyclines and taxanes and in combination with docetaxel in patients failing anthracycline treatment.

Data from phase II studies indicate that in the first of these situations, capecitabine elicits a response in about one-fifth of patients and that responses are associated with symptomatic relief and extended survival. In the latter situation, a phase III study has shown that the combination of docetaxel and capecitabine elicits superior response rates, remission durations, and overall survival compared with the taxane alone and with no clinically important increase in toxicity.

Used alone or in combination, the most notable adverse effect associated with capecitabine is palmar-plantar erythrodysasthesia (hand -foot syndrome), a characteristic complex of reddening, dryness, and soreness of the palms of the hands and soles of the feet, which is rarely disabling and readily managed by treatment interruption and dose reduction.

Pyridoxine treatment and prevention of hand-and-foot syndrome in patients receiving capecitabine

Background. Capecitabine is a novel fluoropyrimidine administered orally for treatment of gastrointestinal and breast malignancies. Toxicity described with capecitabine includes hand-and-foot syndrome (HFS), a potentially painful inflammation of the hands and feet. Pyridoxine has been reported to produce improvement in HFS symptoms. We conducted our study to determine the incidence and severity of HFS symptoms in capecitabine patients and to assess the effects of pyridoxine administered as prophylaxis or treatment.

Patients and methods. We retrospectively reviewed 99 charts of capecitabine patients receiving pyridoxine and 99 charts of those who had not.

Results. Of the 99 pyridoxine patients, 73 (74%) received it as prophylaxis, with the remainder receiving pyridoxine as acute HFS treatment. The median number of capecitabine cycles administered was five, with first-reported HFS onset at cycle 2 in those receiving pyridoxine prophylaxis versus 1.5 in those not (P 5 0.06). Incidence was significantly associated with capecitabine dose, with 76% of patients experiencing HFS in the highest dose ranges compared with 40% in the lowest (P B 0.01). The data did not support that pyridoxine prophylaxis prevented overall HFS incidence in a greater proportion of patients compared with those who did not receive prophylaxis (60% versus 53%, respectively, P 5 NS). However, when used as treatment, a greater proportion of patients receiving pyridoxine reported symptom improvement compared with those not receiving the agent (65% versus 12%, P B0.001). No differences in 12-week tumor response were seen.

Conclusion. The data do not support the use of pyridoxine as prophylaxis as neither the incidence nor the severity of HFS was affected. Once HFS develops, however, pyridoxine may provide some relief of HFS symptoms. A controlled trial of capecitabine with and without pyridoxine seems warranted.

Capecitabine: a novel, orally administered, tumour-activated treatment for colorectal cancer

Objective. To provide a comprehensive review of the preclinical and clinical pharmacology and toxicology of the fluoropyrimidine, capecitabine, with particular reference to its use in its new indication, advanced colorectal cancer.

Data sources. A MEDLINE search was conducted using the term ‘‘capecitabine’’ for the period 1995 -2001. The reference lists from retrieved articles were reviewed and other relevant papers identified. The abstract books from the annual meetings of the American Society of Clinical and Oncology and the European Society of Medical Oncology were also reviewed.

Data extraction. The aim of the review was to be comprehensive and descriptive. All studies containing information deemed to be of interest were reviewed by the author, none were excluded on grounds of quality.

Data synthesis. Capecitabine is a prodrug of the widely used cytotoxic agent 5-fluorouracil (5-FU). Unlike 5-FU it is extensively and reliably absorbed after oral administration and does not require folinate (FA) potentiation. Activation of capecitabine is a three-step enzymatic process. The final activating enzyme, thymidine phosphorylase, is found in unusually high concentrations in many solid tumours, resulting in preferential delivery of 5-FU to tumour tissues, including that of colorectal cancers, suggesting therapeutic potential in this malignancy. Large, randomized trials have demonstrated that capecitabine fulfils this potential—compared with the widely used ‘‘Mayo’’ regimen of intravenous 5-FU and folinic acid, oral capecitabine (1250 mg/m2 twice daily) produced a superior response rate and a similar time to disease progression and duration of survival. It was also better tolerated than 5-FU/FA—of seven common fluoropyrimidine-induced toxicities, four were significantly less common with capecitabine. Capecitabine also produced significantly less grade 4 toxicity or toxicity requiring hospitalization, though the hand -foot syndrome that characterizes prolonged, continuous exposure to 5-FU was more common after capecitabine.

Palmar-plantar erythrodysesthesia

Objective. To provide a comprehensive review of the chemotherapy induced dermatological toxi-city, palmar-plantar erythrodysesthesia (PPE), including clinical presentation, drugs implication in causing the reaction, and approaches for management.

Data sources. A search of MEDLINE (1966-2002), IDIS (1985- 2002) and CANCERLIT (1993-2002) databases was conducted using the terms (and variations of the terms) palmar-plantar erythrodysesthesia, hand-foot syndrome, and acral erythema. Bibliographies from selected articles were also reviewed for appropriate references.

Data extraction. The retrieved literature was reviewed to include all articles pertaining to the incidence, clinical presentation, mechanism, pathology, diagnosis, treatment and prevention of PPE.

Data synthesis. PPE is a distinctive, localized cutaneous reaction to certain antineoplastic agents. A number of drugs have been implicated, including most commonly cytarabine, fluorouracil, doxorubicin, and capecitabine. There appears to be an association with administration schedules that lead to elevated peak plasma concentrations, such as in high-dose therapy, or after prolonged periods of constant exposure, as with continuous infusions, regular oral dosing, or liposomal formulations. The extent and severity of the reaction, time of onset, and duration are variable. Symptoms can occur to both hands and feet, and include dysesthesia, paresthesia, erythema, swelling, pain, blistering, ulceration, and desquamination. Cessation of the offending agent appears to be the most important step in the management of PPE. Dose modification may be necessary for subsequent cycles. As the course of PPE is self-limiting, treatment is commonly supportive and based on the type and severity of symptoms encountered. This can include analgesia, emollient or soothing creams, wound care, and cold compresses. Administration of corticosteroids has produced mixed results. Pyridoxine shows promise as both a treatment and preventative strategy, although confirmation in prospective clinical trials is needed. Advice should be provided to patients to ensure prompt recognition of toxicity and plans for prevention and amelioration of symptoms provided.

Capecitabine for treating head and neck cancer

INTRODUCTION

With an increasing incidence, over half a million cases of head and neck cancer (HNC) are diagnosed annually worldwide. Various chemotherapeutic agents are utilized to achieve adequate locoregional control. Cisplatin, fluorouracil (FU), and taxanes are often used to treat HNC but these regimens have shown high toxicity and poor patient compliance. Capecitabine is an orally administered prodrug that is preferentially converted to FU in tumor cells in comparison to normal cells.

AREA COVERED

In this review, the authors evaluate the role of capecitabine in radical and palliative settings either alone or in combination with other chemotherapeutic drugs in the management of HNC. In addition, metabolic conversion, pharmacokinetics, pharmacodynamics, and toxicity profile of capecitabine are discussed.

EXPERT OPINION

Various phase II trials conducted on capecitabine in the management of recurrent HNC have shown comparable results and tolerable toxic effects especially in pre-treated fragile patients. Capecitabine, used in induction or concurrent settings in the radical management of locoregionally advanced HNC, have also shown promising results. Randomized trials are needed to validate the role of capecitabine in the management of HNC.

A phase 0 clinical trial of novel candidate extended-release formulations of capecitabine

PURPOSE

To examine the pharmacokinetic (PK) profile of several candidate extended-release (ER) formulations of capecitabine in patients.

METHODS

In a phase 0 clinical study, PK profiles of several oral candidate ER formulations of capecitabine were compared to the PK profile of capecitabine after administration of the commercially available immediate-release (IR) tablet. A single dose of 1000 mg IR formulation (two 500 mg tablets) was administered on day 1, and a single dose of a 1000 mg candidate ER formulation of capecitabine (two 500 mg tablets) was administered on day 2. Candidate ER formulations of capecitabine differed with regard to the amount of the ER excipient (Kollidon(®) SR) in tablet matrix (0-5 % w/w) and coating (0-12 mg/cm(2)).

RESULTS

PK profiles of nine different candidate ER formulations were examined. The tablet coating seemed the main determinant for ER of capecitabine and tablet integrity. Average (±standard deviation) AUC0-2h, relative to AUC0-2h after oral administration of the IR tablet, were 43.3 % (±34.9 %) and 1.2 % (±1.2 %) for candidate ER formulations coated with 3 and 6 mg/cm(2), respectively. Corresponding AUC0-last were 93.6 % (±40.2 %) and 44.0 % (±5.4 %).

CONCLUSION

Modulation of capecitabine release in patients can be accomplished by varying tablet coating content. Proof of principle was demonstrated for candidate ER formulations with coating content of 3 mg/cm(2).

Incorporating Historical Data in Bayesian Phase I Trial Design: The Caucasian-to-Asian Toxicity Tolerability Problem

Following phase I dose-finding oncology trials completed in Western countries, Asian investigators often conduct further phase I trials to determine the maximum tolerated dose for Asian patients. This may be due to concerns about possible differences in treatment tolerability between Caucasian and Asian patient groups. Our proposed approach aims to appropriately borrow strength from a previous Caucasian trial to improve the maximum tolerated dose determination in an Asian population of patients. We design an Asian phase I trial using the Bayesian continual reassessment method. First we analyze toxicity data from a Caucasian trial to derive the prior distributions for a subsequent Asian trial. Then, we calibrate the informativeness of the prior distributions according to prior effective sample size defined by Morita et al. Extensive simulation studies demonstrate favourable operating characteristics of the proposed method, compared with two methods based on power and noninformative priors, respectively.

Current and advancing treatments for metastatic colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is one of the leading causes of cancer deaths worldwide. Despite the introduction of several new drugs targeting the vascular endothelial growth factor or epidermal growth factor receptor (EGFR) signaling pathways, survival and disease control in metastatic CRC remains poor.

AREAS COVERED

Chemotherapy based on fluoropyrimidines and irinotecan or oxaliplatin has been the cornerstone of CRC standard of care for several decades. Optimal regimens are selected according to toxicity profiles and patient characteristics. The addition of targeted drugs inhibiting angiogenesis, notably bevacizumab, aflibercept and ramucirumab, has improved chemotherapy outcomes in metastatic CRC. Anti-EGFR agents, cetuximab and panitumumab, in combination with chemotherapy have also improved survival in patients with wild-type RAS tumors. In the refractory setting, there are emerging drugs such as regorafenib or TAS-102 that also have demonstrated impact on outcomes.

EXPERT OPINION

Drugs targeting signaling pathways involved in tumorigenesis improve patient outcomes over chemotherapy alone. Determining the most suitable combination and sequence should be carefully selected, with studies yet to provide a definitive solution to this unknown. Molecular mechanisms of colorectal cancer are at the forefront of research. Knowledge in this domain will help overcome resistance to therapies and introduce new drugs in the personalized CRC therapeutic scenario.

Inside the biochemical pathways of thymidylate synthase perturbed by anticancer drugs: Novel strategies to overcome cancer chemoresistance

Our current understanding of the mechanisms of action of antitumor agents and the precise mechanisms underlying drug resistance is that these two processes are directly linked. Moreover, it is often possible to delineate chemoresistance mechanisms based on the specific mechanism of action of a given anticancer drug. A more holistic approach to the chemoresistance problem suggests that entire metabolic pathways, rather than single enzyme targets may better explain and educate us about the complexity of the cellular responses upon cytotoxic drug administration. Drugs, which target thymidylate synthase and folate-dependent enzymes, represent an important therapeutic arm in the treatment of various human malignancies. However, prolonged patient treatment often provokes drug resistance phenomena that render the chemotherapeutic treatment highly ineffective. Hence, strategies to overcome drug resistance are primarily designed to achieve either enhanced intracellular drug accumulation, to avoid the upregulation of folate-dependent enzymes, and to circumvent the impairment of DNA repair enzymes which are also responsible for cross-resistance to various anticancer drugs. The current clinical practice based on drug combination therapeutic regimens represents the most effective approach to counteract drug resistance. In the current paper, we review the molecular aspects of the activity of TS-targeting drugs and describe how such mechanisms are related to the emergence of clinical drug resistance. We also discuss the current possibilities to overcome drug resistance by using a molecular mechanistic approach based on medicinal chemistry methods focusing on rational structural modifications of novel antitumor agents. This paper also focuses on the importance of the modulation of metabolic pathways upon drug administration, their analysis and the assessment of their putative roles in the networks involved using a meta-analysis approach. The present review describes the main pathways that are modulated by TS-targeting anticancer drugs starting from the description of the normal functioning of the folate metabolic pathway, through the protein modulation occurring upon drug delivery to cultured tumor cells as well as cancer patients, finally describing how the pathways are modulated by drug resistance development. The data collected are then analyzed using network/netwire connecting methods in order to provide a wider view of the pathways involved and of the importance of such information in identifying additional proteins that could serve as novel druggable targets for efficacious cancer therapy.

Maintenance treatment with capecitabine and bevacizumab in metastatic colorectal cancer (CAIRO3): a phase 3 randomised controlled trial of the Dutch Colorectal Cancer Group

BACKGROUND

The optimum duration of first-line treatment with chemotherapy in combination with bevacizumab in patients with metastatic colorectal cancer is unknown. The CAIRO3 study was designed to determine the efficacy of maintenance treatment with capecitabine plus bevacizumab versus observation.

METHODS

In this open-label, phase 3, randomised controlled trial, we recruited patients in 64 hospitals in the Netherlands. We included patients older than 18 years with previously untreated metastatic colorectal cancer, with stable disease or better after induction treatment with six 3-weekly cycles of capecitabine, oxaliplatin, and bevacizumab (CAPOX-B), WHO performance status of 0 or 1, and adequate bone marrow, liver, and renal function. Patients were randomly assigned (1:1) to either maintenance treatment with capecitabine and bevacizumab (maintenance group) or observation (observation group). Randomisation was done centrally by minimisation, with stratification according to previous adjuvant chemotherapy, response to induction treatment, WHO performance status, serum lactate dehydrogenase concentration, and treatment centre. Both patients and investigators were aware of treatment assignment. We assessed disease status every 9 weeks. On first progression (defined as PFS1), patients in both groups were to receive the induction regimen of CAPOX-B until second progression (PFS2), which was the study's primary endpoint. All endpoints were calculated from the time of randomisation. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00442637.

FINDINGS

Between May 30, 2007, and Oct 15, 2012, we randomly assigned 558 patients to either the maintenance group (n=279) or the observation group (n=279). Median follow-up was 48 months (IQR 36-57). The primary endpoint of median PFS2 was significantly improved in patients on maintenance treatment, and was 8·5 months in the observation group and 11·7 months in the maintenance group (HR 0·67, 95% CI 0·56-0·81, p<0·0001). This difference remained significant when any treatment after PFS1 was considered. Maintenance treatment was well tolerated, although the incidence of hand-foot syndrome was increased (64 [23%] patients with hand-foot skin reaction during maintenance). The global quality of life did not deteriorate during maintenance treatment and was clinically not different between treatment groups.

INTERPRETATION

Maintenance treatment with capecitabine plus bevacizumab after six cycles of CAPOX-B in patients with metastatic colorectal cancer is effective and does not compromise quality of life.

FUNDING

Dutch Colorectal Cancer Group (DCCG). The DCCG received financial support for the study from the Commissie Klinische Studies (CKS) of the Dutch Cancer Foundation (KWF), Roche, and Sanofi-Aventis.

Pilot study investigating the prognostic significance of thymidine phosphorylase expression in patients with metastatic breast cancer: a single institution retrospective analysis

Background

The thymidine phosphorylase (TP) enzyme is expressed in higher levels in cancer tissue when compared with normal tissue. It is involved in the intratumoral activation of widely prescribed pyrimidine-derived antimetabolites such as 5′-deoxy-5-fluorouridine and capecitabine (Xeloda^®). The purpose of this study was to determine the clinical correlation between TP expression in tumor tissue and the clinical outcome of capecitabine-based therapy in patients with locally advanced (stage III) or metastatic breast cancer (stage IV).

Methods

The following variables were analyzed as potential determinants of benefit from a capecitabine-based therapy: TP expression, estrogen receptor (ER) and progesterone receptor (PR) status, human epidermal growth factor receptor-2 status, and Ki67 status. This was accomplished by immunohistochemical analysis of paraffin-embedded cancer tissues from 18 patients with breast cancer treated with at least one cycle of capecitabine. Clinical outcome was measured as time to progression.

Results

TP staining intensities in both the invasive and in situ components in patients with lobular and ductal carcinomas were reported. Higher levels of TP in the invasive component were expressed in ER-negative tumors when compared with ER-positive tumors (P<0.05). The ER-positive group expressing lower levels of TP had a median time to progression of 13 months compared with the ER-negative group expressing higher levels of TP which had a median time to progression of 7.5 months (P=0.14).

Conclusion

Patients with ER-positive tumors expressing lower levels of TP exhibit a longer time to progression when compared with patients with ER-negative tumors. Consequently, tumor TP expression does not seem to predict the outcome of capecitabine-based chemotherapy.

Incidence and relative risk of grade 3 and 4 diarrhoea in patients treated with capecitabine or 5-fluorouracil: a meta-analysis of published trials

AIM

Capecitabine is an oral fluoropyrimidine that can effectively replace infusional 5-fluorouracil (5-FU) for treatment of colorectal, gastric and breast cancer. This study aims to analyze the incidence and the relative risk of grade 3 and 4 diarrhoea in patients treated with capecitabine or 5-FU in randomized clinical trials (RCTs).

METHODS

MEDLINE and Cochrane Library were reviewed for RCTs that compared capecitabine with 5-FU for treatment of solid malignancies. The incidence and relative risk (RR) of grade 3/4 diarrhoea were estimated for each arm in the overall population and in colorectal cancer (CRC) patients

RESULTS

Twenty-three studies and 15,761 patients were included. Among these 8303 and 7458 patients received capecitabine or 5-FU based therapies, respectively. In the overall populations severe diarrhoea was reported in 16.6% (95% CI 15.8, 17.4) and in 12.7% (95% CI 11.9, 13.4) of patients treated with capecitabine or 5-FU-based therapies, respectively. The RR was 1.39 (95% CI 1.14, 1.69, P = 0.0010). In 14,899 CRC patients, the incidence of severe diarrhoea was 17.0% (95% CI 16.2, 17.9) and 12.9% (95% CI 12.1, 13.7), respectively, with a RR of 1.46 (95% CI 1.18, 1.81, P < 0.0001). In CRC patients treated with combined chemotherapy, the RR was 1.40 (95% CI 1.07, 1.82; P = 0.01) for patients receiving oxaliplatin and 2.35 (95% CI 1.76, 3.13; P < 0.0001) for patients receiving irinotecan.

CONCLUSIONS

Treatment with capecitabine is characterized by an increased risk of severe diarrhoea, mainly in patients affected by CRC and treated with polichemotherapy. Combination treatment with irinotecan doubles the risk over 5-FU.

A multicenter phase II study of biweekly capecitabine in combination with oxaliplatin as first-line chemotherapy in patients with locally advanced or metastatic gastric cancer

Purpose

We evaluated the safety and efficacy of biweekly capecitabine in combination with oxaliplatin in previously untreated patients with locally advanced or metastatic gastric cancer.

Methods

Patients received oral capecitabine 1,000 mg/m² twice daily on days 1–10 plus oxaliplatin 85 mg/m² as a 2-h intravenous infusion on day 1, every 2 weeks (XELOX). The primary endpoint was overall response rate. Secondary endpoints included progression-free survival, overall survival, and toxicity.

Results

From March 2007 to October 2010, 46 patients were enrolled in this phase II study. The median age was 64 years (range 32–85). A total of 391 (median 7.5, range 1–29) cycles were delivered. Among the 41 patients evaluable for tumor response, 9 showed partial response and 25 had stable disease. The overall response rates of the evaluable and intent-to-treat (ITT) populations were 22 % (95 % CI 10–42 %) and 20 % (95 % CI 9–34 %), respectively. In the ITT analysis, the progression-free survival and overall survival were 5.6 months (95 % CI 4.1–6.3 months) and 8.0 months (95 % CI 6.3–10.1 months), respectively. The most common hematological toxicities were thrombocytopenia (35 %) and leucopenia (34 %), whereas the most common non-hematological toxicities were neuropathy (35 %), fatigue (33 %), diarrhea (27 %), vomiting (26 %), and hand-foot syndrome (25 %). Major grade 3–4 toxicities were anemia (11 %), diarrhea (9 %), and hand-foot syndrome (7 %). No patient died of treatment-related toxicities.

Conclusions

Although the biweekly XELOX regimen failed its primary response rate endpoint, it showed modest efficacy and an acceptable safety profile in the treatment of advanced gastric cancer.

Capecitabine: the new generation of fluoropyrimidines in colorectal cancer

Colorectal cancer is the second leading cause of cancer death in the USA and fluoropyrimidines have been the mainstay of treatment for over 40 years. Currently, capecitabine is the only orally available fluoropyrimidine approved for treatment in the USA. As a single agent it has demonstrated activity and equivalence to 5-fluorouracil (5-FU) intravenous administration via the Mayo Clinic regimen, in both the metastatic and adjuvant settings. Ongoing clinical trials are evaluating the efficacy of capecitabine in combination with oxaliplatin and irinotecan as more convenient substitutes for infusional 5-FU in the 5-FU/leucovorin/oxaliplatin and 5-FU/irinotecan regimens.

Pharmacokinetic evaluation of capecitabine in breast cancer

INTRODUCTION

Capecitabine , an oral prodrug of 5-fluorouracil (5-FU), is adsorbed in its intact form through the intestine and metabolized to 5-FU in tumour cells. In metastatic breast cancer (MBC), capecitabine is an effective and well-tolerated therapeutic option both in monotherapy and in combination with chemotherapeutic or molecular-targeted agents.

AREAS COVERED

We summarized data on pharmacokinetics and pharmacodynamics of capecitabine. We also produced a general review of the most relevant clinical studies of capecitabine in MBC. A literature search was performed using PubMed database including selected articles published in English language up to October 2012.

EXPERT OPINION

The unique pharmacodynamic/pharmacokinetic features represent the bases of the reduced toxicity and the activity of capecitabine in several tumours. Although during the past 10 years there has been an increasing use of this drug in MBC both as single agent and in combination, encouraging results of well tolerated and active combinations with novel agents will lead to a more extensive and protracted use of capecitabine. In view of this, some aspects should be further clarified such as the optimal starting dose and the introduction of alternative schedules of treatment.

Simulations to Assess Phase II Noninferiority Trials of Different Doses of Capecitabine in Combination With Docetaxel for Metastatic Breast Cancer

A phase II trial in metastatic breast cancer (MBC) (NO16853) failed to show noninferiority (progression-free survival, PFS) of capecitabine 825 mg/m² plus docetaxel 75 mg/m² to the registered capecitabine dose of 1,250 mg/m² plus docetaxel 75 mg/m². We developed a modeling framework based on NO16853 and the pivotal phase III MBC study, SO14999, to characterize the link between capecitabine dose, tumor growth, PFS, and survival to simulate response to a range of capecitabine doses and determine a minimum capecitabine dose noninferior to 1,250 mg/m². Simulation showed NO16853 had little power to demonstrate noninferiority (69%). The power reached 80% with a 1,000 mg/m² starting dose and an increased number of PFS events. A starting dose of 1,000 mg/m² could be established as noninferior in terms of efficacy to the registered dose in the second-line MBC setting, with a potentially improved safety, in line with medical practice.

Phase 2 study of capecitabine and irinotecan combination chemotherapy (modified XELIRI regimen) in patients with advanced gastric cancer

OBJECTIVE

The prognosis of patients with advanced gastric cancer (AGC) remains poor, and no single chemotherapy regimen is recognized as a global standard. A phase 2 trial was conducted to determine the efficacy and tolerability of the modified combination regimen of capecitabine and irinotecan (mXELIRI) in patients with AGC.

METHODS

Patients with earlier untreated AGC received intravenous irinotecan (125 mg/m) over 90 minutes on days 1 and 8, and oral capecitabine (850 mg/m) twice daily on days 2 to 15, every 3 weeks. Treatment was continued for at most 8 cycles or until disease progression or intolerable toxicity.

RESULTS

Thirty-two patients were enrolled. In total, 141 cycles of mXELIRI were administered. The overall response rate was 43.7%, with 1 complete response and 13 partial responses. At a median follow-up of 16.2 months, median time to progression and overall survival were 5.6 months (95% confidence interval, 4.27-6.93 mo) and 11.0 months (95% confidence interval, 8.71-13.29 mo), respectively. The most common hematological adverse event was neutropenia (n=18, 56.3%); grade 3 neutropenia was observed in 5 patients, with neutropenic fever in only 2 patients. The most common grade 3/4 nonhematological toxicities were anorexia (n=3, 9.4%), nausea (n=3, 9.4%), vomiting (n=2, 6.3%), and diarrhea (n=2, 6.3%). There was no treatment-related death.

CONCLUSIONS

mXELIRI is a safe and effective first-line treatment for unresectable and metastatic gastric cancer with a manageable tolerability profile. It can be used as one of the first-line treatment options for patients with AGC.

Evaluation of oral chemotherapy with capecitabine and cyclophosphamide plus thalidomide and prednisone in prostate cancer patients

PURPOSE

The aim of this study was to evaluate clinical outcomes of second-line chemotherapy with capecitabine and cyclophosphamide (CTX) plus thalidomide and prednisone in refractory advanced castrate-resistant prostate cancer (CRPC) patients.

METHODS

We retrospectively reviewed patients with advanced CRPC who had previously progressed to first-line docetaxel-based chemotherapy. Patients were given second-line chemotherapy with capecitabine and CTX plus thalidomide and prednisone throughout the course. Patients were evaluated for response and toxicity, and treatment was continued until the disease progression or excessive toxicity was noted.

RESULTS

From April 2007 to February 2010, a total of 28 patients (median age, 72.8 ± 2.9 years) received second-line chemotherapy. The median cycle and duration of metronomic chemotherapy were six (range: 1-12) cycles and 6.3 (range 1.5-20.5) months, respectively. Prostatic-specific antigen was decreased by more than 50% in 10 (35.7%) of the 28 patients. All patients had bone metastases, and 8 patients (28.6%) had measurable soft tissue lesions. Among the 8 patients, 1 patient achieved partial response, and 3 patients had stabilized disease. With a median follow-up time of 29.5 (95% CI, 26.4-33.4) months, median composite progression-free survival and overall survival were 4.7 (95% CI, 3.4-5.7) months and 19.5 (95% CI, 18.9-25.5) months, respectively. No grade 3-4 toxicity was observed, and none of the patients experienced grade 3-4 hematological and nonhematological toxicities.

CONCLUSIONS

These data suggested that oral combination second-line chemotherapy with capecitabine and CTX plus thalidomide and prednisone offers promising activity with an excellent safety profile for patients with advanced CRPC.

Pharmacokinetic analysis of capecitabine and cisplatin in combination with trastuzumab in Japanese patients with advanced HER2-positive gastric cancer

PURPOSE

To evaluate the pharmacokinetics (PK) of capecitabine and cisplatin, administered in combination with or without trastuzumab, in Japanese patients with HER2-positive advanced gastric cancer (AGC).

METHODS

Patients eligible for this PK study (study JP19959), which was carried out during treatment Cycle 1 of the ToGA study, received either capecitabine and cisplatin (XP arm) or trastuzumab plus capecitabine and cisplatin (HXP arm). All patients received capecitabine (1,000 mg/m(2) orally, twice daily for 14 days) and cisplatin (80 mg/m(2) intravenous infusion on Day 1). Patients in the HXP arm also received trastuzumab (8 mg/kg intravenous infusion on Day 1), concurrently with capecitabine. No further study medication was administered during study JP19959. Serial plasma samples for PK analysis were obtained at intervals before and after the administration of capecitabine and cisplatin on Day 1.

RESULTS

Twenty-two patients were enrolled in this PK study: eight in the HXP arm and 14 in the XP arm. All blood samples were available for PK analysis. Co-administration of trastuzumab resulted in no statistically or clinically significant changes in the PK profiles of capecitabine or its metabolites, or of cisplatin (total or unbound platinum).

CONCLUSIONS

Variability in the AUC(last) and C (max) values for the capecitabine was consistent with the known PK profile of capecitabine and fell within established limits. Concurrent trastuzumab therapy is unlikely to alter the PK or safety profile of capecitabine or cisplatin in Japanese patients with HER2-positive AGC.

Optimizing chemotherapy dose and schedule by Norton-Simon mathematical modeling

BACKGROUND

to hasten and improve anticancer drug development, we created a novel approach to generating and analyzing preclinical dose-scheduling data so as to optimize benefit-to-toxicity ratios.

METHODS

we applied mathematical methods based upon Norton-Simon growth kinetic modeling to tumor-volume data from breast cancer xenografts treated with capecitabine (Xeloda®, Roche) at the conventional schedule of 14 days of treatment followed by a 7-day rest (14-7).

RESULTS

the model predicted that 7 days of treatment followed by a 7-day rest (7-7) would be superior. Subsequent preclinical studies demonstrated that this biweekly capecitabine schedule allowed for safe delivery of higher daily doses, improved tumor response, and prolonged animal survival.

CONCLUSIONS

we demonstrated that the application of Norton-Simon modeling to the design and analysis of preclinical data predicts an improved capecitabine dosing schedule in xenograft models. This method warrants further investigation and application in clinical drug development.

Phase II Trial of Capecitabine and Cisplatin in Advanced, Persistent, or Recurrent Carcinoma of the Cervix

Purpose:

Platinum-based drugs are the most active agents in cervical carcinoma. The aim of this study was to assess the activity and toxicity of the association of cisplatin and capecitabine as first-line treatment in patients with advanced, persistent, or recurrent carcinoma of the cervix.

Patients and Methods:

Patients with histological proven primary carcinoma, presence of measurable tumors, age 18 years or older, performance status of 2 or less, and adequate bone marrow, renal, and hepatic functions were potentially eligible for this trial. Prior chemotherapy was allowed only in the context of radiosensitization. Treatment consisted of 50 mg/m2of intravenous cisplatin on day 1 with 2500 mg/m2oral capecitabine daily in 2 divided doses for 14 consecutive days in 21-day cycles. Responses were assessed using response evaluation criteria in solid tumors.

Results:

Between November 2004 and October 2007, 22 women were entered into the trial. Median age was 51 years (range, 37-70 years). Seventeen patients had prior radiotherapy, and 13 received a radiation sensitizer, whereas 2 patients underwent surgery exclusively and 3 patients had no prior treatment. A median of 5 cycles was administered (range, 2-8 cycles). There were one septic death, one grade 4 neutropenia, and one grade 4 anemia. Grade 3 fatigue, gastrointestinal toxicity, renal toxicity, and hand-foot syndrome were seen in 31.8%, 22.7%, 9%, and 9% of the patients, respectively. There were 1 complete response and 6 partial responses for an overall response rate of 31.8%. Seven patients (31.8%) each had stable disease, and 8 patients showed progression. The median time to progression was 7.6 months, with a median overall survival of 20 months.

Conclusion:

These results seem to suggest that the capecitabine-cisplatin combination is a moderately tolerated and active regimen in advanced, persistent, or recurrent cervical carcinoma patients. Further evaluation of this drug combination may be warranted.

Thymidylate synthase and thymidine phosphorylase as predictive markers of capecitabine monotherapy in patients with anthracycline- and taxane-pretreated metastatic breast cancer

PURPOSE

The primary purpose of this study was to evaluate the role of thymidylate synthase (TS) and thymidine phosphorylase (TP) as biomarkers to predict clinical outcomes of capecitabine monotherapy in patients with anthracycline- and taxane-pretreated metastatic breast cancer (MBC).

METHODS

Of the patients who were previously treated with anthracycline and taxane regimens, 90 patients who had available tissue block for immunohistochemistry with measurable lesions were included. All patients received capecitabine (2,500 mg/m(2)/day) for 14 days every 3 weeks.

RESULTS

High TS expression was more common among patients with triple-negative (TN) subtype than among patients with other subtypes (33% for hormone receptor+, 8% for HER2+, and 58% for TN, P = 0.023). The median PFS was significantly lower in patients with high TS (6.6 vs. 3.0 months; P = 0.017) and low TP expressions (6.0 vs. 3.3 months; P = 0.013). A high TS and a low TP expressions were identified as unfavorable independent risk factors for PFS to capecitabine monotherapy in multivariate analysis (hazard ratio [HR], 1.7, P = 0.037 for high TS score; HR, 1.8, P = 0.014 for low TP score).

CONCLUSIONS

Our data suggest that high TS and low TP scores correlate with a shorter PFS for capecitabine monotherapy in patients with anthracycline- and taxane-pretreated MBC.