Dose-Adjusting Capecitabine Minimizes Adverse Effects While Maintaining Efficacy: A Retrospective Review of Capecitabine for Metastatic Breast Cancer

The patient perspective on dose optimization for anticancer treatments: A new era of cancer drug dosing-Challenging the "more is better" dogma

The Patient-Centered Dosing Initiative, a patient-led effort advocating for a paradigm shift in determining cancer drug dosing strategies, pioneers a departure from traditional oncology drug dosing practices. Historically, oncology drug dosing relies on identifying the maximum tolerated dose through phase 1 dose escalation methodology, favoring higher dosing for greater efficacy, often leading to higher toxicity. However, this approach is not universally applicable, especially for newer treatments like targeted therapies and immunotherapies. Patient-Centered Dosing Initiative challenges this "more is better" ethos, particularly as metastatic breast cancer patients themselves, as they not only seek longevity but also a high quality of life since most metastatic breast cancer patients stay on treatment for the rest of their lives. Surveying 1221 metastatic breast cancer patients and 119 oncologists revealed an evident need for flexible dosing strategies, advocating personalized care discussions based on patient attributes. The survey results also demonstrated an openness toward flexible dosing and a willingness from both patients and clinicians to discuss dosing as part of their care. Patient-centered dosing emphasizes dialogue between clinicians and patients, delving into treatment efficacy-toxicity trade-offs. Similarly, clinical trial advocacy for multiple dosing regimens encourages adaptive strategies, moving away from strict adherence to maximum tolerated dose, supported by recent research in optimizing drug dosages. Recognizing the efficacy-effectiveness gap between clinical trials and real-world practice, Patient-Centered Dosing Initiative underscores the necessity for patient-centered dosing strategies. A focus on individual patient attributes aligns with initiatives like Project Optimus and Project Renewal, aiming to optimize drug dosages for improved treatment outcomes at both the pre- and post-approval phases. Patient-Centered Dosing Initiative's efforts extend to patient education, providing tools to initiate dosage-related conversations with physicians. In addition, it emphasizes physician-patient dialogues and post-marketing studies as essential in determining optimal dosing and refining drug regimens. A dose-finding paradigm prioritizing drug safety, tolerability, and efficacy benefits all stakeholders, reducing emergency care needs and missed treatments for patients, aligning with oncologists' and patients' shared goals. Importantly, it represents a win-win scenario across healthcare sectors. In summary, the Patient-Centered Dosing Initiative drives transformative changes in cancer drug dosing, emphasizing patient well-being and personalized care, aiming to enhance treatment outcomes and optimize oncology drug delivery.

A Unified Strategy to Improve Lipid Nanoparticle Mediated mRNA Delivery Using Adenosine Triphosphate

A central goal of chemical and drug delivery sciences is to maximize the therapeutic efficacy of a given drug at the lowest possible dose. Here, we report a generalizable strategy that can be utilized to improve the delivery of mRNA drugs using lipid nanoparticles (LNPs), the clinically approved chemistry platforms utilized in the Moderna and Pfizer/BioNTech COVID-19 vaccines. In brief, our strategy updates the chemistry of LNPs to incorporate adenosine triphosphate (ATP) alongside mRNA, a modification that results in upward of a 79-fold increase in LNP-delivered mRNA-encoded protein expression in vitro and a 24-fold increase in vivo when compared to parent mRNA LNP formulations that do not contain ATP. Notably, we find that our ATP co-delivery strategy increases LNP-delivered mRNA-encoded protein expression across eight different LNP chemistries and three different cell lines, under normoxia and hypoxia, and in a well-tolerated fashion. Notably, our strategy also improves the expression of mRNA encoding for intracellular and secreted proteins both in vitro and in vivo, highlighting the utility of leveraging ATP co-delivery within mRNA LNPs as a means to increase protein expression. In developing this strategy, we hope that we have provided a simple yet powerful approach to improving mRNA LNPs that may one day be useful in developing therapies for human disease.

Antibody drug conjugates: The dos and don'ts in clinical development

Antibody Drug Conjugates (ADCs) entered clinical trials in the mid 1990s to selectively deliver cytotoxic chemotherapy to cancer cells with the goal to increase the antitumor activity and decrease normal tissue toxicity. Over nearly 30 years of development the ADC platform has become established with now 11 approved agents and many more in the pipeline. This review is designed to highlight some of the problems and solutions encountered in clinical development as well as provide practical instruction to both clinical investigators on the efficient protocol design for ADCs and the lessons learned.

Patient-centered dosing: oncologists' perspectives about treatment-related side effects and individualized dosing for patients with metastatic breast cancer (MBC)

PURPOSE

Although metastatic breast cancer (MBC) is treatable, it is not curable and most patients remain on treatment indefinitely. While oncologists commonly prescribe the recommended starting dose (RSD) from the FDA-approved label, patient tolerance may differ from that seen in clinical trials. We report on a survey of medical oncologists' perspectives about treatment-related toxicity and willingness to discuss flexible dosing with patients.

METHODS

We disseminated a confidential survey via social media/email in Spring 2021. Eligible respondents needed to be US-based medical oncologists with experience treating patients with MBC.

RESULTS

Of 131 responses, 119 were eligible. Physicians estimated that 47% of their patients reported distressing treatment-related side effects; of these, 15% visited the Emergency Room/hospital and 37% missed treatment. 74% (n = 87) of doctors reported improvement of patient symptoms after dose reduction. 87% (n = 104) indicated that they had ever, if appropriate, initiated treatment at lower doses. Most (85%, n = 101) respondents did not believe that the RSD is always more effective than a lower dose and 97% (n = 115) were willing to discuss individualized dosing with patients.

CONCLUSION

Treatment-related side effects are prevalent among patients with MBC, resulting in missed treatments and acute care visits. To help patients tolerate treatment, oncologists may decrease initial and/or subsequent doses. The majority of oncologists reject the premise that a higher dose is always superior and are willing to discuss individualized dosing with patients. Given potential improvements regarding quality of life and clinical care, dose modifications should be part of routine shared decision-making between patients and oncologists.

Host and gut bacteria share metabolic pathways for anti-cancer drug metabolism

Pharmaceuticals have extensive reciprocal interactions with the microbiome, but whether bacterial drug sensitivity and metabolism is driven by pathways conserved in host cells remains unclear. Here we show that anti-cancer fluoropyrimidine drugs inhibit the growth of gut bacterial strains from 6 phyla. In both Escherichia coli and mammalian cells, fluoropyrimidines disrupt pyrimidine metabolism. Proteobacteria and Firmicutes metabolized 5-fluorouracil to its inactive metabolite dihydrofluorouracil, mimicking the major host mechanism for drug clearance. The preTA operon was necessary and sufficient for 5-fluorouracil inactivation by E. coli, exhibited high catalytic efficiency for the reductive reaction, decreased the bioavailability and efficacy of oral fluoropyrimidine treatment in mice and was prevalent in the gut microbiomes of colorectal cancer patients. The conservation of both the targets and enzymes for metabolism of therapeutics across domains highlights the need to distinguish the relative contributions of human and microbial cells to drug efficacy and side-effect profiles.

The relationship between eGFR and capecitabine efficacy/toxicity in metastatic breast cancer

The objective of this study was to evaluate the efficacy and toxicity of capecitabine in metastatic breast cancer (mBC) according to the estimated glomerular filtration rate (eGFR). A total of 135 patients included in the final analysis were stratified into 3 categories according to baseline eGFR, i.e., eGFR <60 mL/min/1.73 m² (Group 1), eGFR 60-90 mL/min/1.73 m² (Group 2) and eGFR >90 mL/min/1.73 m² (Group 3). If a patient developed a level of toxicity that would lead to capecitabine dose reduction, this was recognized as dose-limiting toxicity (DLT). The dose was reduced due to toxicity in 95 cycles. A total of 95 DLTs were seen in 76 (56.2%) of the 135 patients. When 76 patients with DLT were evaluated according to eGFR, DLT was observed in 93.3% of those in Group 1, 72.5% of those in Group 2 and 41.3% of those in Group 3 (p < 0.001). The median time to progression (TTP) of all patients was 7.4 months. No significant difference in TTP was observed in patients stratified into 3 groups according to eGFR. When the patients were divided into two groups as DLT and without DLT, the median TTP was 8.68 months (95% CI, 7.53-9.81 months) in those with toxicity and 6.23 months (95% CI, 4.04-8.43 months) in those without toxicity (log-rank p = 0.004). We found a significant relationship between low eGFR and increased risk of DLT. Having a DLT was associated with a longer TTP. It indicates the need for more data/larger study investigating these discrepancies.

Tolerance-based capecitabine dose escalation after DPYD genotype-guided dosing in heterozygote DPYD variant carriers: a single-center observational study

OBJECTIVE

Certain polymorphisms of the DPYD gene encoding for the dihydropyrimidine dehydrogenase (DPD) enzyme are associated with fluoropyrimidine-induced toxicity. Dose reductions of the fluoropyrimidine prodrug capecitabine are recommended for patients carrying these DPYD variants to prevent toxicities. Capecitabine dose escalation after an initial genotype-guided dose reduction is advocated when treatment is well tolerated. However, practical guidelines on how to implement these dose escalations are lacking. We implemented a protocol for tolerance-guided capecitabine dosing in DPYD variant carriers and aimed to explore its effect on toxicity of treatment.

PATIENTS AND METHODS

Patients receiving capecitabine-based chemotherapy for different types of solid tumors were identified retrospectively. Capecitabine doses were reduced in case of a DPYD variant (DPYD*2A, c.2846A>T, DPYD*13, or c.1236G>A) and subsequently adjusted on the basis of tolerance. Outcome was evaluated by clinical chart review and dosing characteristics from the hospital pharmacy. Results were compared with a cohort of capecitabine-treated DPYD wild-type patients.

RESULTS

Of 185 patients eligible for analysis, 11 patients were heterozygous for a DPYD variant. A median dose escalation of 8.5% was achieved using the prespecified protocol. One DPYD variant carrier experienced a grade 3 toxicity after a dose escalation. Overall, DPYD variant carriers did not experience more, or more severe toxicities than DPYD wild-type patients. The total prevalence of severe toxicities in the wild-type group was 43.1% and is comparable with the literature.

CONCLUSION

Tolerance-based capecitabine dose escalation did not lead to more toxicity in DPYD variant carriers compared with wild-type patients. Our results can guide future prospective research.

Effect of capecitabine combined with docetaxel on intestinal flora, liver function, and clinical prognosis in patients with breast cancer liver metastases

BACKGROUND

The prevalence of breast cancer is currently on the rise. Although the development of medical technology has resulted in effective control of breast cancer, lymphatic metastasis of breast cancer reduces the lifespan of patients to 9 mo to 2 years. Breast cancer liver metastasis is a common form of metastasis and is very serious. At present, chemotherapy as an effective treatment for liver metastasis, has many side effects, and adjuvant chemotherapy drugs are used clinically to reduce the side effects of the patients. Currently, capecitabine and endocrine drugs are commonly used in maintenance chemotherapy. Capecitabine, one of the effective drugs for the treatment of liver metastasis of breast cancer, can somewhat improve liver function parameters such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and has a positive effect on patient survival.

AIM

To investigate the effect of capecitabine combined with docetaxel on intestinal flora, liver function, and clinical prognosis in patients with liver metastases from breast cancer.

METHODS

From August 2015 to August 2018, 72 patients with liver metastases from breast cancer were randomly divided into two groups (A and B), with 36 patients in each group. Group A was treated with capecitabine combined with docetaxel, and group B was treated with capecitabine combined with vinorelbine. The changes of intestinal flora and liver function and clinical prognosis were compared between the two groups.

RESULTS

After treatment, the changes in intestinal flora were significantly different between the two groups (P < 0.05). Compared with the pretreatment values, there were significant improvements in plasma endotoxin and liver function parameters (ALT and AST) in both groups A and B after treatment (P < 0.05). After treatment, the levels of plasma endotoxin, ALT, and AST in group A were significantly higher than those in group B (P < 0.05). There was no significant difference in clinical prognosis between the two groups after treatment (P > 0.05).

CONCLUSION

Capecitabine combined with docetaxel has a slightly more active effect in the treatment of metastatic breast cancer than capecitabine combined with vinorelbine, because capecitabine combined with docetaxel has a positive effect on intestinal flora, liver function, and clinical prognosis in these patients.

Vinorelbine plus Capecitabine (Vinocap): a retrospective analysis in heavily pretreated HER2 negative metastatic breast cancer patients

PURPOSE

Metastatic breast cancer is regarded as an incurable entity. In heavily pretreated patients with increasingly limited options for palliative management, ensuring proper quality of life continues is to be an elusive issue. With this in mind, the authors evaluated the efficacy and safety of the Vinorelbine/Capecitabine doublet (VINOCAP).

PATIENTS AND METHODS

The investigators retrospectively analyzed a cohort of 67 women with HER2 negative MBC treated at a large breast cancer practice and a local cancer center with Vinorelbine 22.5 mg/m2 IV on days 1 and 8 combined with Capecitabine 1 g PO BID for 14 consecutive days of 21 day cycles. Patients had been treated with an average of 4 prior lines of chemotherapy. Patient characteristics and outcomes were evaluated.

RESULTS

A total of 67 patients received VINOCAP, and an additional 2 underwent repeat exposure yielding a cohort of 69. Clinical benefit rate, defined as complete response (CR), partial response (PR) or stable disease ≥ 6 months (SD), was 55.07%. Complete response was seen in 4.34%, PR in 18.8% and SD ≥ 6 months in 31.9%. Median progression-free survival was 6.2 months and overall survival 35.47 months after VINOCAP exposure. The most common grade 3-4 toxicity was neutropenia in 10% of cases. Dose had to be reduced in 18% of cases due to toxicity of any type. The regimen was well tolerated, and serious side effects were uncommon.

CONCLUSION

Vinorelbine/Capecitabine appears to be an active and well-tolerated regimen in women with MBC. In particular, encouraging was the efficacy of VINOCAP as fourth or greater line of chemotherapy.

5-fluorouracil Toxicity Mechanism Determination in Human Keratinocytes: in vitro Study on HaCaT Cell Line

5-fluorouracil (5-FU) and capecitabine therapy is often accompanied by palmar-plantar erythrodysesthesia (PPE) which is manifestation of 5-FU toxicity in keratinocytes. The main mechanisms of 5-FU action are thymidylate synthase (TS) inhibition which can be abrogated by thymidine and strengthened by calciumfolinate (CF) and incorporation of fluorouridinetriphosphate into RNA which can be abrogated by uridine. For proper PPE treatment 5-FU mechanism of action in keratinocytes needs to be elucidated. We used the 5-FU toxicity modulators uridine, thymidine and CF to discover the mechanism of 5-FU action in human keratinocyte cell line HaCaT. To measure the cellular viability, we used MTT test and RTCA test. CF did not augment 5-FU toxicity and 5-FU toxicity was weakened by uridine. Therefore, the primary mechanism of 5-FU toxicity in keratinocytes is 5-FU incorporation into RNA. The uridine protective effect cannot fully develop in the presence of CF. Thymidine addition to 5-FU and uridine treated cells not only prevents the toxicity-augmenting CF effect but it also prolongs the 5-FU treated cells survival in comparison to uridine only. Therefore, it can be assumed that in the presence of uridine the 5-FU toxicity mechanism is switched from RNA incorporation to TS inhibition. Although particular 5-FU toxicity mechanisms were previously described in various cell types, this is the first time when various combinations of pyrimidine nucleosides and CF were used for 5-FU toxicity mechanism elucidation in human keratinocytes. We suggest that for PPE treatment ointment containing uridine and thymidine should be further clinically tested.

Dose- and time-dependence of the host-mediated response to paclitaxel therapy: a mathematical modeling approach

It has recently been suggested that pro-tumorigenic host-mediated processes induced in response to chemotherapy counteract the anti-tumor activity of therapy, and thereby decrease net therapeutic outcome. Here we use experimental data to formulate a mathematical model describing the host response to different doses of paclitaxel (PTX) chemotherapy as well as the duration of the response. Three previously described host-mediated effects are used as readouts for the host response to therapy. These include the levels of circulating endothelial progenitor cells in peripheral blood and the effect of plasma derived from PTX-treated mice on migratory and invasive properties of tumor cells in vitro. A first set of mathematical models, based on basic principles of pharmacokinetics/pharmacodynamics, did not appropriately describe the dose-dependence and duration of the host response regarding the effects on invasion. We therefore provide an alternative mathematical model with a dose-dependent threshold, instead of a concentration-dependent one, that describes better the data. This model is integrated into a global model defining all three host-mediated effects. It not only precisely describes the data, but also correctly predicts host-mediated effects at different doses as well as the duration of the host response. This mathematical model may serve as a tool to predict the host response to chemotherapy in cancer patients, and therefore may be used to design chemotherapy regimens with improved therapeutic outcome by minimizing host mediated effects.

Supporting adherence to oral anticancer agents: clinical practice and clues to improve care provided by physicians, nurse practitioners, nurses and pharmacists

Background

Healthcare provider (HCP) activities and attitudes towards patients strongly influence medication adherence. The aim of this study was to assess current clinical practices to support patients in adhering to treatment with oral anticancer agents (OACA) and to explore clues to improve the management of medication adherence.

Methods

A cross-sectional, observational study among HCPs in (haemato-)oncology settings in Belgium and the Netherlands was conducted in 2014 using a composite questionnaire. A total of 47 care activities were listed and categorised into eight domains. HCPs were also asked about their perceptions of adherence management on the items: insight into adherence, patients’ communication, capability to influence, knowledge of consequences and insight into causes. Validated questionnaires were used to assess beliefs about medication (BMQ) and shared decision making (SDM-Q-doc).

Results

In total, 208 HCPs (29% male) participated; 107 from 51 Dutch and 101 from 26 Belgian hospitals. Though a wide range of activities were reported, certain domains concerning medication adherence management received less attention. Activities related to patient knowledge and adverse event management were reported most frequently, whereas activities aimed at patient’s self-efficacy and medication adherence during ongoing use were frequently missed. The care provided differed between professions and by country. Belgian physicians reported more activities than Dutch physicians, whereas Dutch nurses and pharmacists reported more activities than Belgian colleagues. The perceptions of medication adherence management were related to the level of care provided by HCPs. SDM and BMQ outcomes were not related to the care provided.

Conclusions

Enhancing the awareness and perceptions of medication adherence management of HCPs is likely to have a positive effect on care quality. Care can be improved by addressing medication adherence more directly e.g., by questioning patients about (expected) barriers and discussing strategies to overcome them, by asking for missed doses and offering (electronic) reminders to support long-term medication adherence. A multidisciplinary approach is recommended in which the role of the pharmacist could be expanded.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3110-2) contains supplementary material, which is available to authorized users.

Efficacy and safety of low-dose capecitabine plus docetaxel versus single-agent docetaxel in patients with anthracycline-pretreated HER2-negative metastatic breast cancer: results from the randomized phase III JO21095 trial

PURPOSE

The randomized phase III JO21095 trial compared the efficacy and safety of low-dose capecitabine plus docetaxel combination therapy (XT) versus single-agent administration of docetaxel in anthracycline-pretreated HER2-negative metastatic breast cancer.

METHODS

Patients were randomized to either low-dose XT (capecitabine 825 mg/m² twice daily, days 1-14; docetaxel 60 mg/m², day 1 every 3 weeks) or docetaxel (70 mg/m², day 1 every 3 weeks). The primary objective was to demonstrate superior progression-free survival (PFS) with low-dose XT versus single-agent docetaxel. Overall survival (OS) and safety were secondary endpoints.

RESULTS

In total, 162 patients were treated. Median PFS was 10.5 months with low-dose XT and 9.8 months with single-agent docetaxel (hazard ratio [HR] 0.62 [95% confidence interval (CI) 0.40-0.97]; p = 0.03). The OS HR was 0.89 (95% CI 0.52-1.53; p = 0.68). Grade ≥3 treatment-related toxicities occurred in 74% of XT-treated patients and 76% of docetaxel-treated patients. The main differences in grade ≥3 treatment-related toxicities were hand-foot syndrome (7.3% of XT-treated patients vs 0% receiving docetaxel), fatigue/malaise (2.4 vs 10.0%), and peripheral edema (1.2 vs 7.5%). Dose modifications were required in 100% of low-dose XT and 49% of docetaxel patients. Toxicity-related treatment discontinuations occurred in 18 and 33%, respectively.

CONCLUSION

The improved PFS with low-dose XT versus docetaxel alone is consistent with higher-dose XT phase III experience, but the safety profile was more favorable and manageable.

Adherence and Patients' Experiences with the Use of Capecitabine in Daily Practice

Introduction: Capecitabine is a widely prescribed oral anticancer agent. We studied medication adherence and explored its use in daily practice from a patients' perspective.

Patients and Methods: Patients (n = 92) starting capecitabine were followed up to five 3-week cycles. Adherence was assessed using a pill count, pharmacy data and dosing information from the patients' medical file. Self-reported adherence was measured using the Medication Adherence Report Scale (MARS). At baseline and during week 2 of cycles 1, 3, and 5, patients filled out questionnaires about quality of life, symptoms, attitude toward medicines and disease and use in daily practice. Simultaneously, blood samples were taken to determine the area under the curve (AUC) of 5′-deoxy-5-fluorouridine (5′-DFUR), 5-fluorouracil (5-FU), and α-fluoro-β-alanine (FBAL) by a population pharmacokinetic model. Associations between AUCs and patient-reported symptoms were tested for cycles 3 and 5.

Results: Most patients (84/92; 91%) had an adherence rate of ≥95 and ≤ 105%. The percentage of patients reporting any non-adherence behavior measured with MARS increased from 16% at cycle 1 to 29% at cycle 5. Symptoms were reported frequently and the dosing regimen was adjusted by the physician at least once in 62% of patients. In multivariate analysis the probability of an adjustment increased with the number of co-medication (OR 1.19, 95% CI: 1.03–1.39) and a stronger emotional response to the disease (OR 1.32, 95% CI: 1.10–1.59). The AUC of 5′-DFUR was associated with weight loss (OR 1.10, 95% CI: 1.01–1.19), AUC of FBAL with hand-foot syndrome (OR 0.90, 95% CI: 0.83–0.99), rhinorrhea (OR 1.21, 95% CI: 1.03–1.42 weight loss (OR 1.09, 95% CI: 1.00–1.20) and depression (OR 0.90, 95% CI: 0.82–0.99). Side effects were reported by one third of patients as the reason to discontinue treatment.

Conclusion: Adherence to capecitabine was generally high. Nevertheless, adherence measured with MARS decreased over time Adherence management to support implementation of correct capecitabine use is specifically relevant in longer term treatment. In addition, it appears that adverse event management is important to support persistence. With the extending armamentarium of oral targeted anticancer agents and prolonged treatment duration, we expect the issue of medication adherence of increasing importance in oncology.

The role of pharmacogenetics in capecitabine efficacy and toxicity

Capecitabine is an oral prodrug of 5-fluorouracil (5-FU) and approved for treatment of various malignancies. Hereditary genetic variants may affect a drug's pharmacokinetics or pharmacodynamics and account for differences in treatment response and adverse events among patients. In this review we present the current knowledge on genetic variants, commonly single-nucleotide polymorphisms (SNPs), tested in cohorts of cancer patients and possibly useful for prediction of capecitabine efficacy or toxicity. Capecitabine is activated to 5-FU by CES, CDA and TYMP, of which SNPs in CDA and CES2 were found to be associated with efficacy and toxicity. In addition, variants in genes of the 5-FU metabolic pathway, including TYMS, MTHFR and DPYD also influenced capecitabine efficacy and toxicity. In particular, well-known SNPs in TYMS and DPYD as well as putative DPYD SNPs had an association with clinical outcome as well as adverse events. Inconsistent findings may be attributable to factors related to ethnic differences, sample size, study design, study endpoints, dosing schedule and the use of multiple agents. Of the SNPs described in this review, dose reduction of fluoropyrimidines based on the presence of DPYD variants ^*2A (rs3918290), ^*13 (rs55886062), -2846A>T (rs67376798) and -1236G>A/HapB3 (rs56038477) has already been recommended. Other variants merit further validation to establish their definite role in explanation of interindividual differences in the outcome of capecitabine-based therapy.

Combining Fulvestrant with Low-Dose Capecitabine is Effective and Tolerable in Woman with Metastatic Breast Cancer

Although the use of endocrine therapy in combination with intravenous chemotherapy has not been standardized, the combination of fulvestrant and chemotherapy may be promising. A 62-year-old woman came to our hospital's outpatient clinic with extensive ascites. Approximately 10 years earlier, she had undergone mastectomy and sentinel lymph node biopsy. Pathologically invasive lobular carcinoma, with a maximum diameter of 28 mm, had been diagnosed in the left breast. The cancer had a histological grade of 2, was positive for estrogen receptor (95% or more positive cells), and was negative for both progesterone receptor (less than 1% positive cells) and human epidermal growth factor receptor 2. For 5 years the patient underwent adjuvant endocrine therapy with tamoxifen and then with anastrozole. Four years 2 months after adjuvant endocrine therapy had been completed, she felt abdominal distention, and her symptoms gradually worsened. A series of intensive examinations indicated that the invasive lobular carcinoma had metastasized to the peritoneum, pleura, uterus, and bone. Aromatase inhibitor was administered as a first-line therapy for the metastatic disease and was accompanied by denosumab injected every 28 days. For 2 months after the start of treatment with anastrozole, the ascites did not decrease and tumor markers increased. Because anastrozole had not been effective, fulvestrant (500 mg) and low-dose capecitabine (500 mg) were administered for the first 21 days of a 28-day cycle; this regimen had been shown by a phase 2 trial to be effective and tolerable in patients with metastatic breast cancer. The patient felt an improvement in abdominal distention, and the tumor markers decreased 2 weeks after the start of this combination therapy. By 10 months after the start of the combined therapy the ascites had decreased and pleural effusion had completely disappeared. The uterine wall became thinner, and the endometrial cavity became smaller. Tumor markers continued decreasing. No adverse events were observed. The combination of fulvestrant and low-dose capecitabine is promising because of its efficacy and tolerability for the treatment of patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer.

Decreased gastrointestinal toxicity associated with a novel capecitabine schedule (7 days on and 7 days off): a systematic review

Capecitabine is widely used in the management of metastatic breast cancer; however, drug delivery is limited by gastrointestinal and other toxicity. We employed mathematical modeling to rationally design an optimized dose and schedule for capecitabine of 2,000 mg twice daily, flat dosing, 7 days on, 7 days off. Preclinical data suggested increased efficacy and tolerability with this novel dosing, and three early-phase clinical trials have suggested a favorable toxicity profile. To further define the tolerability of this regimen, we conducted a systematic review of the gastrointestinal adverse events of patients on these studies. This review demonstrated a favorable gastrointestinal toxicity profile with capecitabine in this novel schedule when given as single agent or in combination therapy with either bevacizumab or lapatinib. No patients discontinued therapy for gastrointestinal toxicity, and there were no grade 4 or 5 gastrointestinal toxicities reported. Grade 3 or greater diarrhea occurred in two (2%); grade 2 or greater mucositis, constipation, and vomiting were reported in three (4%) patients. We conclude that capecitabine administered on a 7 days on, 7 days off schedule has limited gastrointestinal toxicity. Our methodology was based on an analysis of individual patient toxicity data from one phase I single-agent capecitabine and two phase II capecitabine combination studies (with bevacizumab and lapatinib, respectively), focusing specifically on gastrointestinal toxicity.

Efficacy and safety of capecitabine-based first-line chemotherapy in advanced or metastatic breast cancer: a meta-analysis of randomised controlled trials

We sought to evaluate the efficacy and safety of capecitabine-based therapy as first-line chemotherapy in advanced breast cancer. Randomised controlled trials of capecitabine monotherapy or combined treatment were included in the meta-analysis. PubMed, EMBASE, the Cochrane Library database and important meeting summaries were searched systematically. Outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and grades 3-4 drug-related adverse events.Nine trials with 1798 patients were included. The results indicated a significant improvement with capecitabine-based chemotherapy compared with capecitabine-free chemotherapy in ORR (relative risk [RR] 1.14, 95% confidence interval [CI] 1.03 to 1.26, P = 0.013) and PFS (hazard ratio [HR] 0.77, 95% CI 0.69 to 0.87, P < 0.0001). Overall survival favoured capecitabine-based chemotherapy, but this was not significant. There were more incidences of neutropenia and neutropenic fever in the capecitabine-free chemotherapy group and more vomiting, diarrhoea and hand-foot syndrome in the capecitabine-based chemotherapy group. There were no significant differences in nausea, fatigue, cardiotoxicity or mucositis/stomatitis between the two treatment regimens.Capecitabine-based chemotherapy significantly improves ORR and PFS in patients with advanced breast cancer, but has no demonstrable impact on OS. Capecitabine-based regimens are suitable as first-line treatment for patients with advanced breast cancer.

Paclitaxel and bevacizumab with or without capecitabine as first-line treatment for HER2-negative locally recurrent or metastatic breast cancer: a multicentre, open-label, randomised phase 2 trial

BACKGROUND

The addition of bevacizumab to paclitaxel or capecitabine has demonstrated improved progression-free survival (PFS) and objective response rate (ORR) as compared with chemotherapy alone in patients with HER2-negative locally recurrent or metastatic breast cancer (LR/MBC). We evaluated the efficacy and safety of first-line therapy of paclitaxel and bevacizumab with or without capecitabine in patients with HER2-negative LR/MBC.

METHODS

In this multicentre, open-label, randomised phase II trial, women with HER2-negative LR/MBC were randomly assigned in a 1:1 ratio to paclitaxel (90 mg/m2 intravenously [IV] on days 1, 8, and 15) and bevacizumab (10 mg/kg IV on days 1 and 15) every 4 weeks for six cycles, followed by bevacizumab (15 mg/kg IV on day 1) every 3 weeks (AT) or to paclitaxel (90 mg/m2 IV on days 1 and 8), bevacizumab (15 mg/kg IV on day 1) and capecitabine (825 mg/m2 orally twice daily on days 1–14) every 3 weeks for eight cycles, followed by bevacizumab and capecitabine at the same doses every 3 weeks (ATX). The primary end-point was investigator-assessed PFS. Secondary end-points included ORR, duration of response, overall survival (OS) and safety. Exploratory analyses were conducted to evaluate the impact of capecitabine on OS and to validate a novel prognostic model. This trial is registered with EudraCT, number 2006-006058-83.

FINDINGS

Median PFS was significantly longer in ATX as compared with AT (11.2 months versus 8.4 months; stratified hazard ratio (HR), 0.52; 95% confidence interval (CI), 0.41–0.67; p < 0.0001). The ORR in ATX patients with measurable disease (n = 268) was higher than that in AT (69% versus 51%; p = 0.01). The median duration of response was 6.8 versus 5.4 months for, respectively, ATX and AT (p < 0.0001). Median OS was 24.2 months for ATX and 23.1 months for AT (p = 0.53). The increased rate of grade 3–4 adverse events related to the addition of capecitabine, being hand-foot syndrome (34% versus 0% for AT) and neutropenia (20% versus 12% for AT), generally did not preclude continuation of treatment. Exploratory analyses indicated that (1) patients receiving capecitabine at some line for treatment have significantly improved OS and (2) a prognostic model can classify patients into three risk groups associated with OS.

INTERPRETATION

In patients with HER2-negative LR/MBC, addition of capecitabine to paclitaxel and bevacizumab significantly improved PFS, ORR and response duration. This combination was reasonably well tolerated and may be considered of use as first-line treatment in rapidly progressive disease.

FUNDING

F. Hoffmann-La Roche Ltd, the Netherlands.

First-line chemotherapy with docetaxel plus capecitabine followed by capecitabine or hormone maintenance therapy for the treatment of metastatic breast cancer patients

The primary aim of the present study was to evaluate whether maintenance therapy with capecitabine or hormone replacement therapy (HRT) results in improved progression-free survival (PFS) in metastatic breast cancer (MBC) patients who had previously achieved disease control with first-line docetaxel plus capecitabine (TX) chemotherapy. Seventy-nine metastatic breast cancer patients treated between January 2008 and June 2013 with TX chemotherapy were retrospectively analyzed. Following successful initial disease control by the combination chemotherapy, 39 patients received single-agent capecitabine maintenance therapy and 40 patients received HRT as maintenance therapy. The PFS time, objective response rate, clinical benefit rate and safety of the two groups were compared. The median PFS of the total cohort (n=79) was 11.0 months. Furthermore, the median PFS time of the capecitabine (n=39) and HRT groups (n=40) were 10.9 and 11.1 months, respectively (P=0.283). Compared with the PFS time of maintenance treatment only, single-agent capecitabine treatment following TX chemotherapy prolonged the PFS time by 6.8 months and HRT following TX chemotherapy prolonged PFS time by 5.8 months (P=0.551). Of the total cohort, 49 patients did not receive palliative endocrine therapy prior to chemotherapy, including 22 patients in the capecitabine maintenance group and 27 patients in the HRT maintenance group. The PFS time from the commencement of maintenance treatment was significantly different between the two groups, 6.1 months in the capecitabine group compared with 11.5 months in the HRT group (P=0.045). For the 30 patients who underwent palliative endocrine therapy prior to TX chemotherapy, the PFS times of the capecitabine and HRT maintenance treatment groups were 7.5 and 4.1 months, respectively (P=0.043). However, the occurrence of adverse events, such as hematological and gastrointestinal toxicity, as well as hand-foot syndrome, were not significantly different between the two groups. The current study indicated that single-agent capecitabine maintenance therapy may be a potential treatment strategy for MBC patients who responded to capecitabine-based chemotherapy. In particular, capecitabine may provide a more effective maintenance treatment duration compared with HRT for patients who had previously undergone first-line palliative HRT for MBC.

A pooled analysis of gemcitabine plus docetaxel versus capecitabine plus docetaxel in metastatic breast cancer

In two randomized phase III trials of patients with metastatic breast cancer (MBC), gemcitabine-docetaxel (GD) and capecitabine-docetaxel (CD) had similar efficacy, but distinct safety profiles. Methods. Data from two GD versus CD studies were pooled; overall survival (OS), progression-free survival (PFS), and overall response rate (ORR) were determined. Cox proportional hazards models identified prognostic factors associated with improved OS and PFS. Using a multivariate prognostic model incorporating identified adverse prognostic factors, we grouped MBC patients into low-, intermediate-, and high-risk categories. Hazard ratios (HRs) of GD over CD for OS and PFS were determined for subsets of patients. Results. Baseline demographics of the pooled population were mostly well balanced. In the pooled population, there were no significant differences between GD versus CD for OS (HR = 1.02; p = .824), PFS (HR = 1.15; p = .079), and ORR (p = .526). In the pooled crossover population, there were trends toward improved OS (HR = 0.82; p = .171) and PFS (HR = 0.93; p = .557) with GD. Several prognostic factors (including prior adjuvant taxane) for improved OS or PFS were identified; however, there were no significant interactions between treatment arms and prognostic factors for PFS or OS, except number of metastatic sites. In the prognostic model, median OS and PFS were numerically lower in the high-risk group versus the intermediate- and low-risk groups. Conclusion. This analysis confirms the lack of efficacy difference between GD and CD in the pooled population, crossover population, and almost all subpopulations. Several prognostic factors were associated with improved outcomes in the pooled population.

A high-throughput yeast assay identifies synergistic drug combinations

Drug combinations are commonly used in the treatment of a range of diseases such as cancer, AIDS, and bacterial infections. Such combinations are less likely to be thwarted by resistance, and they have the desirable potential to be synergistic. Synergistic combinations can have decreased toxicity if lower doses of the constituent agents can be used. Conversely, antagonistic combinations can lead to lower efficacy of a treatment. Unfortunately, practical limitations, including the large number of possible combinations to be tested and the importance of optimizing concentrations and order of addition, discourage systematic studies of compound combinations. To address these limitations, we present a platform to screen drug combinations at multiple concentrations with varying orders of addition in Saccharomyces cerevisiae, at high throughput. In a proof of principle, we screened all possible pairwise combinations of 11 DNA damaging agents and found that of the 66 combinations tested, six were synergistic and three were antagonistic. The strength of two-thirds of these combinations was dependent on the order in which the drugs were added to the cells. We further tested the synergistic and antagonistic combinations in two cancer cell lines and found the combination of mitomycin C and irinotecan to be synergistic in both cell lines. This pilot study demonstrates the utility of using yeast for screening large matrices of drug combinations, and it provides a means to prioritize drug combination tests in human cells. Finally, we underscore the importance of testing the order of addition for assessing drug combinations.

Phase II trial of fulvestrant with metronomic capecitabine for postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer

BACKGROUND

In this phase II study, we explored efficacy and toxicity of combined endocrine and low-dose metronomic chemotherapy therapy consisting of fulvestrant and capecitabine in estrogen and/or progesterone receptor-positive, HER2-negative MBC.

PATIENTS AND METHODS

Patients with ≤ 1 previous hormonal treatment in the metastatic setting received an injection fulvestrant loading dose 500 mg on day 1, 250 mg on days 15 and 29 followed by 250 mg every 28 days along with continuous oral capecitabine in divided doses. The total fixed daily dose of capecitabine was either 1500 mg or 2000 mg, depending on the patient's weight (< 80 kg vs. ≥ 80 kg). Primary end points were PFS and TTP. Toxicity was assessed by continuous evaluations of treatment-emergent adverse events (AEs) and changes from baseline in laboratory values.

RESULTS

Forty-one women, with a mean age of 64.5 years, were enrolled. Patients completed a median of 11 monthly treatment cycles. Median PFS was 14.98 months (95% confidence interval [CI], 7.26-upper limit [UL] not estimated) and median TTP was 26.94 months (95% CI, 7.26-UL not estimated). Median overall survival was 28.65 months (95% CI, 23.95-UL not estimated). Treatment was well tolerated with < 10% Grade 3 palmar-plantar erythrodysesthesia. Overall, the most frequent AEs were palmar-plantar erythrodysesthesia, fatigue, and nausea.

CONCLUSION

Fulvestrant with metronomic capecitabine demonstrates substantial activity in hormone receptor-positive MBC and is well tolerated. Combined chemoendocrine approaches should be further explored considering the low toxicity of the combination with meaningful TTP.

Fixed-dose capecitabine is feasible: results from a pharmacokinetic and pharmacogenetic study in metastatic breast cancer

The pro-drug capecitabine is approved for treatment of anthracycline- and paclitaxel-resistant metastatic breast cancer. However, toxicity and large interpatient pharmacokinetic variability occur despite body surface area (BSA)-dosing. We hypothesized that a fixed-dose schedule would simplify dosing and provide an effective and safe alternative to BSA-based dosing. We conducted an open label, single-arm, two-stage study of oral capecitabine with fixed starting dose (3,000 mg total daily dose in two divided doses × 14 days q21 days) in patients with metastatic breast cancer. We correlated pharmacodynamic endpoints [e.g., efficacy (response) per RECIST and toxicity], adherence and pharmacokinetics/pharmacogenetics. Sample size of 45 patients was required to detect a 25 % response rate from null response rate of 10 % using a Simon two-stage design. Twenty-six patients were enrolled in the first-stage and 21 were evaluable after a median of four cycles of capecitabine. Two thirds of patients received either the same dose or a dose 500 mg lower than what would have been administered with a commonly used 2,000 mg/m(2) BSA-dosing schedule. Eight patients had stable disease but progressed after a median of seven cycles. Despite a clinical benefit rate of 19 %, no RECIST responses were observed following the first stage and the study was closed. Dose-reductions were required for grade 2 hand-foot syndrome (28 %) and vomiting (5 %). Adherence was similar when using both patient-reported and Medication Event Monitoring System methods. High interpatient variability was observed for capecitabine and metabolite pharmacokinetics, but was not attributed to observed pharmacogenetic or BSA differences. Single agent activity of capecitabine was modest in our patients with estrogen receptor-positive or -negative metastatic breast cancer and comparable to recent studies. BSA was not the main source of pharmacokinetic variability. Fixed-dose capecitabine is feasible, and simplifies dosing.

Dasatinib plus capecitabine for advanced breast cancer: safety and efficacy in phase I study CA180004

PURPOSE

Dasatinib is an Src family kinase inhibitor with modest activity in advanced breast cancer. We aimed to assess toxicity and maximum tolerated dose (MTD) for dasatinib plus capecitabine, estimate efficacy, and explore effects on angiogenesis.

EXPERIMENTAL DESIGN

Dose levels (DL) were dasatinib 50 mg twice daily (DL1), 70 mg twice daily (DL2 and DL3), or 100 mg daily (DL3a); plus capecitabine on days 1 to 14 of a 21-day cycle, at 825 mg/m(2) twice daily (DL1 and DL2) or 1,000 mg/m(2) twice daily [DL3 and DL3a (MTD)]. DL3a was expanded to evaluate safety/efficacy. Plasma samples were collected for biomarker analysis.

RESULTS

Thirty-one and 21 patients were treated in the escalation and expansion phases. Sixty percent of tumors were hormone receptor-positive. Most common adverse events (AE) were any grade nausea (58%), hand-foot syndrome (44%), diarrhea (33%), fatigue (33%), vomiting (31%), and asthenia (31%). Most common grade 3/4 AEs were hand-foot syndrome (12%), diarrhea (8%), fatigue (8%), pleural effusion (8%), and vomiting (6%). The MTD was defined at DL3a (capecitabine 1,000 mg/m(2) twice daily and dasatinib 100 mg daily). Of 25 response-evaluable patients treated at DL3a, confirmed partial response was noted in 24% and stable disease in an additional 32%; median progression-free survival was 14.4 weeks. Significant decreases in plasma VEGF-A and increases in VEGFR-2 and collagen-IV were observed.

CONCLUSIONS

Dasatinib 100 mg once daily plus capecitabine 1,000 mg/m(2) twice daily were tolerable and were associated with clinical benefit in 56% of response-evaluable patients. Biomarker changes were consistent with an antiangiogenic effect.

Pooled analysis of individual patient data from capecitabine monotherapy clinical trials in locally advanced or metastatic breast cancer

We assessed the efficacy and safety of capecitabine across treatment lines, and the impact of patient and disease characteristics on outcomes using data from phase II/III trials. Individual patient data were pooled from seven Roche/Genentech-led trials conducted from 1996 to 2008 where single-agent capecitabine was the test or control regimen for metastatic breast cancer (MBC). Data were analyzed from 805 patients: 268 in the first-line metastatic setting and 537 in the second-line or later setting. Baseline characteristics were balanced across treatment lines. Patients receiving second-line or later versus first-line capecitabine had lower objective response rates (ORR: 19.0 vs. 25.0 %, respectively, odds ratio 0.70; 95 % CI: 0.5-1.0) and significantly shorter progression-free survival (PFS: median 112.0 days [3.7 months] vs. 150.0 days [4.9 months]; p < 0.0001) and overall survival (OS: median 396.0 days [13.0 months] vs. 666.0 days [21.9 months]; p < 0.0001). In multivariate analysis by backward elimination, significantly improved ORR (p = 0.0036), PFS (p < 0.0001) and OS (p < 0.0001) with capecitabine were demonstrated in patients with estrogen receptor (ER) and/or progesterone receptor (PgR)-positive versus both ER and PgR-negative tumors. Hand-foot syndrome (HFS) was the most common adverse event (AE) in 63 % of patients. Overall, 7 % of patients discontinued and two patients (<1 %) died from treatment-related AEs. Significantly improved survival was observed in patients developing capecitabine-related HFS (p < 0.0001 PFS/OS) or diarrhea (p = 0.004 OS; p = 0.0045 PFS) versus patients without these events. In this pooled analysis of individual patient data, first-line capecitabine was associated with improved ORR, PFS, and OS versus second or later lines. Multivariate analyses identified greater ORR, PFS, and OS with capecitabine in patients with ER and/or PgR-positive versus ER/PgR-negative tumors. Safety was in-line with previous phase III trials in MBC.

A phase II trial of capecitabine in combination with the farnesyltransferase inhibitor tipifarnib in patients with anthracycline-treated and taxane-resistant metastatic breast cancer: an Eastern Cooperative Oncology Group Study (E1103)

Capecitabine produces an objective response rate of up to 25% in anthracycline-treated, taxane-resistant metastatic breast cancer (MBC). The farnesyltransferase inhibitor tipifarnib inhibits Ras signaling and has clinical activity when used alone in MBC. The objective of this study was to determine the efficacy and safety of tipifarnib-capecitabine combination in MBC patients who were previously treated with an anthracycline and progressed on taxane therapy. Eligible patients received oral capecitabine 1,000 mg/m2 twice daily plus oral tipifarnib 300 mg twice daily on days 1-14 every 21 days. The primary endpoint was ORR. The trial was powered to detect an improvement in response rate from 25 to 40%. Among 63 eligible, partial response occurred in six patients (9.5%; 90% CI 4.2-17.9%), median progression-free survival was 2.6 months (95% CI 2.1-4.4), and median overall survival was 11.4 months (95% CI 7.7-14.0). Dose modifications were required for 43 patients (68%) for either tipifarnib and/or capecitabine. Grades 3 and 4 toxicities were seen in 30 patients (44%; 90% CI 44.4-67.0%) and 11 patients (16%; 90% CI 10.8-29.0%), respectively. The most common grade 3 toxicities included neutropenia, nausea, and vomiting; and the most common grade 4 toxicity was neutropenia (8 out of 11 cases). The tipifarnib-capecitabine combination is not more effective than capecitabine alone in MBC patients who were previously treated with an anthracycline and taxane therapy.

Phase II study of bevacizumab in combination with trastuzumab and capecitabine as first-line treatment for HER-2-positive locally recurrent or metastatic breast cancer

We report the first results from a phase II, open-label study designed to evaluate the efficacy and safety of bevacizumab in combination with trastuzumab and capecitabine as first-line therapy for human epidermal growth factor receptor (HER)-2-positive locally recurrent (LR) or metastatic breast cancer (MBC). Patients were aged ≥18 years with confirmed breast adenocarcinoma, measurable LR/MBC and documented HER-2-positive disease. Patients received bevacizumab (15 mg/kg on day 1) plus trastuzumab (8 mg/kg on day 1 of cycle 1, 6 mg/kg on day 1 of each subsequent cycle) plus capecitabine (1,000 mg/m2 twice daily, days 1-14) every 3 weeks until disease progression, unacceptable toxicity, or consent withdrawal. Eighty-eight patients were enrolled; 40 (46%) are still on study treatment. The median follow-up was 8.8 months (range, 0.9-17.1 months). The overall response rate, the primary endpoint, was 73% (95% confidence interval [CI], 62%-82%), comprising 7% complete and 66% partial responses. The median progression-free survival interval was 14.4 months (95% CI, 10.4 months to not reached [NR]), with 35 events. The median time to progression was 14.5 months (95% CI, 10.5 months to NR), with 33 events. Treatment was well tolerated; main side effects were grade 3 hand-foot syndrome (22%), grade ≥3 diarrhea (9%), and grade ≥3 hypertension (7%). Overall, 44% of patients experienced grade ≥3 treatment-related adverse events and 13 patients discontinued capecitabine because of toxicity, but continued with bevacizumab and trastuzumab. Heart failure was seen in two patients. The combination of bevacizumab, trastuzumab, and capecitabine was clinically active as first-line therapy for patients with HER-2-positive MBC, with an acceptable safety profile and no unexpected toxicities.

Capecitabine monotherapy: review of studies in first-line HER-2-negative metastatic breast cancer

The goals of treatment for metastatic breast cancer (MBC) are to prolong overall survival (OS) while maximizing quality of life, palliating symptoms, and delaying tumor progression. For many years, anthracyclines and taxanes have been the mainstay of treatment for MBC, but these agents are now commonly administered earlier in the course of the disease. A recent meta-analysis revealed adverse effects on OS and overall response rates in patients with MBC receiving first-line anthracycline-based chemotherapy following relapse on adjuvant chemotherapy. Noncrossresistant cytotoxic agents and combinations that combine high clinical activity and acceptable tolerability while being convenient for patients are therefore needed for the first-line treatment of MBC patients. Capecitabine has substantial antitumor activity in the first-line treatment of patients with MBC in prospective, randomized, phase II/III clinical trials as monotherapy and in combination with biologic and novel agents. First-line capecitabine monotherapy has a favorable safety profile, lacking myelosuppression and alopecia, and does not compromise the administration of further lines of chemotherapy. Capecitabine is suitable for long-term administration without the cumulative toxicity that can limit the prolonged use of other chemotherapy agents. Here, we review the available data on capecitabine as a single agent for first-line treatment of patients with human epidermal growth factor receptor 2-negative MBC.