Weekly docetaxel in metastatic breast cancer patients: No superior benefits compared to three-weekly docetaxel

Time above threshold plasma concentrations as pharmacokinetic parameter in the comparison of oral and intravenous docetaxel treatment of breast cancer tumors

BACKGROUND

Prolonging the time which plasma concentrations of antimitotic drugs, such as the taxanes, exceed cytotoxic threshold levels may be beneficial for their efficacy. Orally administered docetaxel offers an undemanding approach to optimize such time above threshold plasma concentrations (t C>threshold ).

METHODS

A nonsystematic literature screen was performed to identify studies reporting in-vitro half-maximal inhibitory concentration (IC 50 ) values for docetaxel. Pharmacokinetics of intravenously (i.v.) docetaxel (75 mg/m 2 ) and orally administered docetaxel (ModraDoc006) co-administered with ritonavir (r) given twice daily (30 + 20 mg concomitant with 100 mg ritonavir bis in die) were simulated using previously developed population models. T C>threshold was calculated for a range of relevant thresholds in terms of in-vitro cytotoxicity and plasma concentrations achieved after i.v. and oral administration of docetaxel. A published tumor growth inhibition model for i.v. docetaxel was adapted to predict the effect of attainment of time above threshold levels on tumor dynamics.

RESULTS

Identified studies reported a wide range of in vitro IC 50 values [median 0.04 µmol/L, interquartile range (IQR): 0.0046-0.62]. At cytotoxic thresholds <0.078 µmol/L oral docetaxel shows up to ~7.5-fold longer t C>threshold within each 3-week cycle for a median patient compared to i.v.. Simulations of tumor dynamics showed the increased relative potential of oral docetaxel for inhibition of tumor growth at thresholds of 0.075, 0.05 and 0.005 µmol/L.

CONCLUSION

ModraDoc006/r is superior to i.v. docetaxel 75 mg/m 2 in terms of median time above cytotoxic threshold levels <0.078 µmol/L. This may indicate superior cytotoxicity and inhibition of tumor growth compared to i.v. administration for relatively docetaxel-sensitive tumors.

A systemic review of taxanes and their side effects in metastatic breast cancer

Taxanes-containing chemotherapy constitutes an essential backbone for both early and metastatic breast cancer (mBC). However, the two major taxane drugs—paclitaxel and docetaxel—have distinct safety profiles. In this review, we summarize the safety outcome and management following treatment with both taxanes from selected clinical trials. We utilized PubMed to perform literature search before April 2021. Five phase III randomized controlled trials with reports of individual taxane adverse events (AEs) were included in this review. Grade 3/4 AEs were summarized and discussed extensively. The rates of grade 3/4 neutropenia were higher with docetaxel than with paclitaxel. For non-hematologic grade 3/4 AEs, peripheral neuropathy was more frequent with paclitaxel while fluid retention was more frequent with docetaxel. Compared to paclitaxel, docetaxel had a higher rate of grade 3/4 gastrointestinal AEs. Grade 3/4 myalgia were generally comparable between the two taxanes. Except for neutropenia, the incidence rate of grade 3/4 AEs of taxanes was generally manageable. Peripheral neuropathy was more common with paclitaxel while grade 3/4 neutropenia was more common with docetaxel.

The influence of docetaxel schedule on treatment tolerability and efficacy in patients with metastatic breast cancer: a systematic review and meta-analysis of randomized controlled trials

Background

Administration of single-agent docetaxel in a weekly schedule may offer similar efficacy, with a more favorable toxicity profile, compared to a three-weekly schedule in patients with metastatic breast cancer.

Methods

The original search of Medline, Embase, and Scopus was performed in September 2018 and references were updated with additional searches up to January 2021. Two reviewers independently screened the identified literature based on a predefined set of criteria.

Randomized controlled trials investigating the use of weekly versus three-weekly docetaxel in metastatic breast cancer patients were included.

Results

Four randomized controlled trials (N = 459 patients) were included in the final analyses. No significant differences were found in terms of objective response rate (risk ratio (RR) 0.75, 95% confidence interval (CI): 0.54 – 1.05), progression-free survival (hazard ratio (HR) 0.95, 95% CI: 0.71 – 1.26) or overall survival (HR 0.95, 95% CI: 0.70 – 1.29) between weekly and three-weekly docetaxel, respectively. Weekly docetaxel was associated with a significantly lower risk of grade 3/4 neutropenia (RR 0.16, 95% CI: 0.10 – 0.27), febrile neutropenia (RR 0.21, 95% CI: 0.08 – 0.55), and neuropathy (RR 0.29, 95% CI: 0.11 – 0.78). Although the risk of epiphora (≥ grade 3/leading to treatment withdrawal, RR 3.62, 95% CI: 1.07–12.22) and onycholysis (≥ grade 2/leading to treatment withdrawal, RR 3.90, 95% CI: 1.34 – 11.32) was increased.

Conclusions

Weekly docetaxel is associated with a lower risk of neutropenia, febrile neutropenia and neuropathy than the three-weekly docetaxel schedule in metastatic breast cancer patients. However, the risk of onycholysis, epiphora, and treatment discontinuation seems increased with weekly administration. No significant differences in efficacy outcomes were found. Weekly docetaxel might be an alternative for patients at risk for developing neutropenia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09196-x.

Docetaxel for Breast Cancer Treatment-Side Effects on Ocular Surface, a Systematic Review

Docetaxel is a very effective chemotherapeutic agent for the treatment of metastatic or locally advanced breast cancer. Epiphora (hyperlacrimation) has been shown to be the most common eye condition in patients receiving docetaxel-based chemotherapy. This symptom does not decrease visual acuity, but decreases the quality of life. Daily activities (reading, working on the computer, watching TV, and so on) are affected, with patients complaining about an alteration of daily life with the appearance of this symptom. The mechanism by which epiphora occurs is considered to be the canalicular stenosis, but the trials on the subject failed to reach statistical significance. The objective of this scoping review is to determine whether there is a treatment regimen-dependent relationship between docetaxel administration and the presence of epiphora in women with breast cancer. The inclusion criteria were met by 10 trials, from which one was excluded owing to data selection biases. Accordingly, nine studies were evaluated quantitatively and qualitatively in the present review. We included subjects with docetaxel as single treatment or docetaxel in combination with other chemotherapy compounds. The occurrence of epiphora among subjects treated with docetaxel, regardless of the therapeutic regimen used, was statistically significant (p = 0.005). The proportion of patients with epiphora after weekly administration of docetaxel (54 out of 131 subjects, 41.22%) was different compared with that of those who received docetaxel at three week intervals (112 out of 325 subjects, 34.15%), but the difference between the two was not statistically significant (p = 0.732). The present study demonstrates that epiphora occurs more frequently in patients receiving weekly docetaxel-based chemotherapy than those taking the three-weekly regimen, but the difference is not statistically significant. Ophthalmologic assessment of all patients starting this treatment is recommended. The causal relationship between canalicular stenosis and epiphora is not fully elucidated as long as this ocular symptom occurs in women who do not have stenosis of the lacrimal system. Further well-designed trials are required to bring new insights into the mechanisms of epiphora pathogenesis in subjects treated with docetaxel.

Pharmacokinetics and Toxicities of Oral Docetaxel Formulations Co-Administered with Ritonavir in Phase I Trials

Introduction

Docetaxel is widely used as intravenous (IV) chemotherapy. Oral docetaxel is co-administered with the cytochrome P450 3A4 and P-glycoprotein inhibitor ritonavir to increase oral bioavailability. This research explores the relationship between the pharmacokinetics (PK) and toxicity of this novel oral chemotherapy.

Methods

The patients in two phase I trials were treated with different oral docetaxel formulations in combination with ritonavir in different dose levels, ranging from 20 to 80 mg docetaxel with 100 to 200 mg ritonavir a day. The patients were categorized based on the absence or occurrence of severe treatment-related toxicity (grade ≥3 or any grade leading to treatment alterations). The docetaxel area under the plasma concentration–time curve (AUC) and maximum plasma concentration (C_max) were associated with toxicity.

Results

Thirty-four out of 138 patients experienced severe toxicity, most frequently observed as mucositis, fatigue, diarrhea, nausea and vomiting. The severe toxicity group had a significantly higher docetaxel AUC (2231 ± 1405 vs 1011 ± 830 ng/mL*h, p<0.0001) and C_max (218 ± 178 vs 119 ± 77 ng/mL, p<0.0001) as compared to the patients without severe toxicity. When extrapolated from IV PK data, the patients without severe toxicity had a similar cumulative docetaxel AUC as with standard 3-weekly IV docetaxel, while the C_max was up to 10-fold lower with oral docetaxel and ritonavir.

Conclusion

Severe toxicity was observed in 25% of the patients treated with oral docetaxel and ritonavir. This toxicity seems related to the PK, as the docetaxel AUC_0-inf and C_max were up to twofold higher in the severe toxicity group as compared to the non-severe toxicity group. Future randomized trials will provide a further evaluation of the toxicity and efficacy of the new weekly oral docetaxel and ritonavir regimen in comparison to standard IV docetaxel.

Use of Taxanes in Metastatic HER2-negative Breast Cancer - a Status Report

The most important goal of treatment of patients with metastatic breast cancer is maintenance or even improvement of quality of life. In this setting, chemotherapy should be used with as much restraint as possible. If palliative chemotherapy is indicated, the taxane drug class is an established treatment option. The updated guidelines of the Gynaecological Oncology Working Group (AGO), Breast Committee, of the German Society for Gynaecology and Obstetrics (DGGG) and the German Cancer Society e. V. (DKG) provide recommendations with the greatest possible evidence on which of the licensed taxanes can be used in which treatment situation in the metastatic setting.

Weekly docetaxel monotherapy for metastatic extramammary Paget's disease: Retrospective single-institute analysis

Monthly docetaxel (DTX) monotherapy is the first-line regimen that is preferably used for metastatic extramammary Paget's disease (EMPD). However, the high-dose DTX regimen frequently causes severe hematological adverse events (AE). To overcome such safety concerns, a weekly low-dose DTX monotherapy has been proposed for use in the treatment of various cancer types. In this study, we aimed to evaluate the feasibility and efficacy of weekly DTX (25 mg/m² ) monotherapy for metastatic EMPD by retrospectively analyzing the clinical courses of 14 patients treated with this regimen. Weekly DTX monotherapy was well tolerated and all patients completed the treatment schedule without treatment withdrawal, dose reduction or treatment-related death. While five cases (35.7%) experienced hematological AE, their severity was mild. The response rate was 35.7% (5/14 cases), which included five partial responses. The mean progression-free survival (PFS) and overall survival were 7.1 (95% confidence interval [CI], 5.1-9.1) and 26.4 months (95% CI, 16.7-36.1), respectively. Furthermore, the median PFS was 7.3 months (95% CI, 4.5-10.0) in patients aged 65 years and younger and 7.1 months (95% CI, 4.4-9.9) in patients older than 65 years. These results suggest that weekly DTX monotherapy may be a useful regimen that has a high treatment continuation rate with low levels of hematological toxicity, regardless of the patient's age for metastatic EMPD.

Statistical analysis of patient-reported outcome data in randomised controlled trials of locally advanced and metastatic breast cancer: a systematic review

Although patient-reported outcomes (PROs), such as health-related quality of life, are important endpoints in randomised controlled trials (RCTs), there is little consensus about the analysis, interpretation, and reporting of these data. We did a systematic review to assess the variability, quality, and standards of PRO data analyses in advanced breast cancer RCTs. We searched PubMed for English language articles published in peer-reviewed journals between Jan 1, 2001, and Oct 30, 2017. Eligible articles were those that reported PRO results from RCTs of adult patients with advanced breast cancer receiving anti-cancer treatments with reported sample sizes of at least 50 patients-66 RCTs met the selection criteria. Only eight (12%) RCTs reported a specific PRO research hypothesis. Heterogeneity in the statistical methods used to assess PRO data was observed, with a mixture of longitudinal and cross-sectional techniques. Not all articles addressed the problem of multiple testing. Fewer than half of RCTs (28 [42%]) reported the clinical significance of their findings. 48 (73%) did not report how missing data were handled. Our systematic review shows a need to improve standards in the analysis, interpretation, and reporting of PRO data in cancer RCTs. Lack of standardisation makes it difficult to draw robust conclusions and compare findings across trials. The Setting International Standards in the Analyzing Patient-Reported Outcomes and Quality of Life Data Consortium was set up to address this need and develop recommendations on the analysis of PRO data in RCTs.

The use of patient-reported outcomes in advanced breast cancer clinical trials: a review of the published literature

OBJECTIVE

As a means to measure quantifiable signs, symptoms, and impacts of a disease or its treatment, patient-reported outcome (PRO) instruments can be applied to numerous settings, including use in drug development to support labeling claims. This research summarizes the use of PROs in trials for 16 commonly used regulatory approved treatments for advanced or metastatic breast cancer.

METHODS

For each treatment (n = 16), a literature search was conducted in MEDLINE, Embase, and PsycINFO. The primary criterion for selection was the report of studies that used PROs to evaluate treatment benefit and/or toxicity in advanced or metastatic breast cancer. From this, a sub-set of articles for each treatment were selected for full-text review where PRO-related information was extracted and summarized.

RESULTS

The searches yielded 1727 publications. Following abstract review, 1702 were excluded because they failed to meet criteria, or were duplicates or less relevant for PRO information reported. Thus, 25 articles were reviewed in detail for this evaluation. Eleven PRO instruments were identified from these publications. The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core (EORTC QLQ-C30) was utilized the most frequently (n = 13, 52.0%). Most publications reported PROs positioned as secondary endpoints (n = 20, 80.0%); described some of the statistical analyses applied to PRO data (n = 21, 84.0%); and specified PRO results (n = 23, 92.0%).

CONCLUSIONS

While several of the publications provided some information on how PROs were utilized, many did not describe details for PRO administration, scoring, analyses, and results interpretation. While it is encouraging that PROs are often used in clinical trials for patients with metastatic breast cancer, they are not commonly used to support endpoints that establish the basis for label claims. Because they yield direct insight into the patient experience of a condition, PROs may be used to provide a more comprehensive perspective of the benefits and risks from treatment.

A Phase II Study of Weekly Docetaxel as Second-Line Chemotherapy in Patients With Metastatic Urothelial Carcinoma

The present multicenter phase II study evaluated the efficacy and safety of weekly docetaxel as second-line chemotherapy for metastatic urothelial carcinoma. Weekly docetaxel was well tolerated but demonstrated modest activity, with a response rate of 6%, a median progression-free survival (PFS) of 1.4 months, and a median overall survival (OS) of 8.3 months. The dichotomy between PFS and OS was likely associated with subsequent platinum-based chemotherapy received by 58% of the patients.

BACKGROUND

Docetaxel is commonly used for second-line therapy for metastatic urothelial carcinoma (UC). However, myelosuppression is a substantial concern when the traditional 3-week docetaxel cycle is used. The present multicenter phase II study evaluated the efficacy and safety of weekly docetaxel as second-line chemotherapy for metastatic UC.

PATIENTS AND METHODS

Patients with progression after previous platinum-based chemotherapy for advanced or metastatic disease were treated with docetaxel 30 mg/m(2) on days 1 and 8 every 21 days. The primary endpoint was the response rate.

RESULTS

The study enrolled 31 patients. Their median age was 64 years (range, 40-79 years). An Eastern Cooperative Oncology Group performance status of 1, liver metastasis, and a hemoglobin level < 10 g/dL were observed in 100%, 32%, and 23% of patients, respectively. Previous platinum-based chemotherapy had been administered for metastatic disease in 29 patients (94%). Although fatigue (13%) and anorexia (6%) were the most frequently observed grade 3 to 4 toxicities, the safety profiles were generally mild and manageable. Two patients (6%) achieved an objective response, which was maintained for 3.0 to 7.8 months. Eight patients experienced disease stabilization (disease control rate, 32%). The median progression-free survival (PFS) and overall survival (OS) were 1.4 months (95% confidence interval [CI], 1.3-1.6) and 8.3 months (95% CI, 5.9-10.6), respectively. A relatively long OS was associated with further salvage platinum-based chemotherapy (n = 18, 58%) showing an encouraging activity (response rate, 44%; median PFS, 4.0 months).

CONCLUSION

Second-line chemotherapy with weekly docetaxel was well tolerated but demonstrated modest activity in patients with metastatic UC. A platinum-based combination as second-line treatment might be considered for selected patients.

Use of Cytotoxic Chemotherapy in Metastatic Breast Cancer: Putting Taxanes in Perspective

Agents that target microtubule (MT) dynamics have been used extensively for the treatment of metastatic breast cancer (MBC). Among these agents are taxanes (solvent-based paclitaxel [sb-paclitaxel], docetaxel, and nab-paclitaxel) and non-taxanes, such as eribulin and ixabepilone. Although these agents have been approved for the treatment of MBC, questions regarding the ideal agent, regimen (single agent vs. combination vs. sequential), and schedule still remain. This systematic review examined pivotal trials for taxanes, eribulin, and ixabepilone as well as first-line taxane trials in MBC. Only randomized trials that enrolled ≥ 100 patients were included. Publications on combination regimens with targeted agents were excluded unless they also included a comparison between nontargeted regimens. The studies were grouped into taxane versus taxane, sb-paclitaxel versus non-taxane, and docetaxel versus non-taxane regimens. In taxane versus taxane comparisons, the efficacy of sb-paclitaxel and docetaxel appeared similar, nab-paclitaxel every 3 weeks (q3w) appeared superior to sb-paclitaxel q3w, and weekly nab-paclitaxel appeared superior to docetaxel. In general, taxane regimens demonstrated higher overall response rates (ORRs) versus non-taxane regimens; however, only 2 trials demonstrated longer overall survival (OS) for taxane regimens. Taxanes will likely continue to be used in earlier lines of therapy, whereas eribulin and ixabepilone may be more appropriate for later lines of treatment. Ongoing research may identify biomarkers that could help in selecting the appropriate MT-targeted agent for a given patient.

Overview of neuropathy associated with taxanes for the treatment of metastatic breast cancer

Taxanes are an established option in the standard treatment paradigm for patients with metastatic breast cancer (MBC). Neuropathy is a common, dose-limiting side effect of taxane therapy that is often managed by dose reductions and delays. The severity, time to onset, and improvement in neuropathy are important considerations for patient management and vary among currently approved taxanes. The rate of grade ≥3 neuropathy with taxanes has been shown to be dose and schedule dependent; however, time to improvement to grade ≤1 is typically shorter for nab-paclitaxel than for other taxanes in patients with MBC. Many tools for assessing patient-reported neuropathy exist. Because MBC is incurable and patient quality of life must be critically considered when making treatment decisions, there is a need for more prospective trials to assess patient-reported neuropathy. Validated predictors of taxane-related neuropathy may play an important role in treatment decisions in the future. This review will focus on the toxicity profile (i.e., neuropathy) of each of the taxanes used in the treatment of MBC, will provide updates on tools used for the assessment of neuropathy, and will highlight newly discovered predictors of taxane-related neuropathy.

Chemotherapy and targeted therapy for women with human epidermal growth factor receptor 2-negative (or unknown) advanced breast cancer: American Society of Clinical Oncology Clinical Practice Guideline

PURPOSE

To identify optimal chemo- and targeted therapy for women with human epidermal growth factor 2 (HER2)- negative (or unknown) advanced breast cancer.

METHODS

A systematic review of randomized evidence (including systematic reviews and meta-analyses) from 1993 through to current was completed. Outcomes of interest included survival, progression-free survival, response, quality of life, and adverse effects. Guideline recommendations were evidence based and were agreed on by the Expert Panel via consensus.

RESULTS

Seventy-nine studies met the inclusion criteria, comprising 20 systematic reviews and/or meta-analyses, 30 trials on first-line treatment, and 29 trials on second-line and subsequent treatment. These trials form the evidence base for the guideline recommendations.

RECOMMENDATIONS

Endocrine therapy is preferable to chemotherapy as first-line treatment for patients with estrogen receptor-positive metastatic breast cancer unless improvement is medically necessary (eg, immediately life-threatening disease). Single agent is preferable to combination chemotherapy, and longer planned duration improves outcome but must be balanced against toxicity. There is no single optimal first-line or subsequent line chemotherapy, and choice of treatment will be determined by multiple factors including prior therapy, toxicity, performance status, comorbid conditions, and patient preference. The role of bevacizumab remains controversial. Other targeted therapies have not so far been shown to enhance chemotherapy outcome in HER2-negative breast cancer.

Presentation and management of docetaxel-related adverse effects in patients with breast cancer

The taxane chemotherapeutic agent docetaxel has been utilized in the management of breast cancer in the adjuvant, neoadjuvant and metastatic setting. Although well tolerated by the majority of patients, docetaxel toxicity may limit the dose which can be administered. Adverse events include infusion reactions, febrile neutropenia, fatigue, fluid retention, pneumonitis, cutaneous and nail toxicity, epiphora and lacrimal duct stenosis, gastrointestinal complications, and neuropathies. In this review, we explore these complications and how they can be effectively managed to improve patient quality of life during and following docetaxel therapy.

A randomized phase II study of weekly docetaxel/cisplatin versus weekly docetaxel/oxaliplatin as first-line therapy for patients with advanced gastric cancer

BACKGROUND

Docetaxel, in combination with cisplatin or oxaliplatin, has demonstrated efficacy in advanced gastric cancer (AGC). This randomized, non-comparative phase II trial evaluated two weekly docetaxel-based regimens to determine which is the most promising in terms of efficacy and safety as a front-line therapy in AGC.

METHODS

Chemotherapy-naïve patients with measurable unresectable and/or metastatic gastric adenocarcinoma were randomly assigned to receive docetaxel (35 mg/m(2)) weekly on days 1 and 8 of a 21-day cycle plus either cisplatin (60 mg/m(2) on day 1) (wDP) or oxaliplatin (120 mg/m(2) on day 1) (wDO).

RESULTS

Of the 77 randomly assigned patients, 76 patients (38 per arm) received one of the study treatments. Overall, response rate (ORR) was 37 % for wDP and 41 % for wDO. Median progression-free survival (PFS) was 4.9 and 4.4 months for wDP and wDO, respectively, and median overall survival (OS) was 9.7 and 12.3 months, respectively. Exploratory analyses showed no significant difference between wDP and wDO in terms of ORR (P = 0.707), PFS (P = 0.324), or OS (P = 0.581). The main grade 3 or 4 toxicity in the wDP and wDO groups was neutropenia (47 % in both groups). wDO was less associated with nausea (66 vs. 82 %) and vomiting (39 vs. 63 %), but more associated with peripheral neuropathy (68 vs. 39 %) than wDP. Rates of overall grade 3 or 4 adverse events were similar (wDP 66 vs. wDO 68 %).

CONCLUSIONS

wDP and wDO were found to be equally active and tolerable as front-line treatments in AGC.

Chemotherapy-induced peripheral neurotoxicity: a critical analysis

With a 3-fold increase in the number of cancer survivors noted since the 1970s, there are now over 28 million cancer survivors worldwide. Accordingly, there is a heightened awareness of long-term toxicities and the impact on quality of life following treatment in cancer survivors. This review will address the increasing importance and challenge of chemotherapy-induced neurotoxicity, with a focus on neuropathy associated with the treatment of breast cancer, colorectal cancer, testicular cancer, and hematological cancers. An overview of the diagnosis, symptomatology, and pathophysiology of chemotherapy-induced peripheral neuropathy will be provided, with a critical analysis of assessment strategies, neuroprotective approaches, and potential treatments. The review will concentrate on neuropathy associated with taxanes, platinum compounds, vinca alkaloids, thalidomide, and bortezomib, providing clinical information specific to these chemotherapies.

Phase II randomized trial of weekly and every-3-week ixabepilone in metastatic breast cancer patients

This multicenter, open-label, randomized phase II trial compared the efficacy and tolerability of weekly ixabepilone versus the standard 3 weekly dosing regimen. Patients with human epidermal growth factor receptor 2-negative, metastatic breast cancer (MBC) were randomly assigned to receive either ixabepilone 16 mg/m(2) as a 1-h intravenous (IV) infusion weekly on days 1, 8, and 15 of a 28-day cycle (1 week off therapy; n = 85), or 40 mg/m(2) as a 3-h IV infusion on day 1 of a 21-day cycle (n = 91), until disease progression or unacceptable toxicity. Randomization was stratified by (i) measurable versus nonmeasurable (evaluable) disease, (ii) ≤two versus >two prior chemotherapy regimens for MBC, and (iii) hormone receptor (HR)-positive versus HR-negative breast cancer. The primary endpoint was rate of progression-free survival (PFS) at 6 months. Of 176 randomized patients, 171 were treated. The 6-month PFS rate was significantly higher in patients treated with ixabepilone every 3 weeks (42.7, 95 % confidence interval [CI] 31.5-53.5) compared with those who received ixabepilone weekly (28.6, 95 % CI 18.9-38.9; log-rank P = 0.03). Every-3-week dosing significantly prolonged median PFS versus weekly dosing (5.3 vs. 2.9 months; log-rank P = 0.05). The every-3-week regimen was associated with higher rates of grade 3/4 toxicities, particularly neutropenia (38.2 vs. 6.1 %) and a higher rate of patient withdrawal due to adverse events. These results suggest that every-3-week ixabepilone is more effective than weekly treatment in MBC, albeit with more toxicity.

A phase 1 study of weekly everolimus (RAD001) in combination with docetaxel in patients with metastatic breast cancer

BACKGROUND

Inhibition of mammalian target of rapamycin with everolimus may improve the efficacy of taxanes. Everolimus and docetaxel are both metabolized by CYP3A4, which could result in a pharmacokinetic (PK) interaction.

METHODS

Fifteen patients with metastatic breast cancer were treated with docetaxel (doses of 40-75 mg/m(2) intravenously on day 1 of a 21-day cycle) in combination with everolimus (doses ranging from 20 to 50 mg orally on days 1 and 8 of a 21-day cycle) in a phase 1 trial using the continuous reassessment method to determine maximum tolerated dose. The first 2 patients developed a dose-limiting toxicity (neutropenic infection), prompting a mandatory dose reduction and PK evaluation of both everolimus and docetaxel for patients enrolled in subsequent dosing cohorts.

RESULTS

Fifteen patients were treated. Dose-limiting toxicity included grade 3 mucositis (n = 1), prolonged grade 4 neutropenia (n = 1), and grade 3 infection/febrile neutropenia (n = 3). Day 8 of everolimus was commonly held for neutropenia despite a dose reduction in docetaxel to 40 mg/m(2). Eleven patients underwent complete PK evaluation for everolimus, and 9 patients underwent complete PK evaluation for both everolimus and docetaxel. Widely variable changes in clearance were seen for both drugs, and the study was terminated because of lack of efficacy and concerns regarding toxicity seen with the combination.

CONCLUSIONS

Weekly everolimus in combination with docetaxel every 3 weeks was associated with excessive neutropenia and variable clearance of both drugs, making combination therapy unpredictable, even at low doses of both drugs.

Alterations in tumor necrosis factor signaling pathways are associated with cytotoxicity and resistance to taxanes: a study in isogenic resistant tumor cells

INTRODUCTION

The taxanes paclitaxel and docetaxel are widely used in the treatment of breast, ovarian, and other cancers. Although their cytotoxicity has been attributed to cell-cycle arrest through stabilization of microtubules, the mechanisms by which tumor cells die remains unclear. Paclitaxel has been shown to induce soluble tumor necrosis factor alpha (sTNF-α) production in macrophages, but the involvement of TNF production in taxane cytotoxicity or resistance in tumor cells has not been established. Our study aimed to correlate alterations in the TNF pathway with taxane cytotoxicity and the acquisition of taxane resistance.

METHODS

MCF-7 cells or isogenic drug-resistant variants (developed by selection for surviving cells in increasing concentrations of paclitaxel or docetaxel) were assessed for sTNF-α production in the absence or presence of taxanes by enzyme-linked immunosorbent assay (ELISA) and for sensitivity to docetaxel or sTNF-α by using a clonogenic assay (in the absence or presence of TNFR1 or TNFR2 neutralizing antibodies). Nuclear factor (NF)-κB activity was also measured with ELISA, whereas gene-expression changes associated with docetaxel resistance in MCF-7 and A2780 cells were determined with microarray analysis and quantitative reverse transcription polymerase chain reaction (RTqPCR).

RESULTS

MCF-7 and A2780 cells increased production of sTNF-α in the presence of taxanes, whereas docetaxel-resistant variants of MCF-7 produced high levels of sTNF-α, although only within a particular drug-concentration threshold (between 3 and 45 nM). Increased production of sTNF-α was NF-κB dependent and correlated with decreased sensitivity to sTNF-α, decreased levels of TNFR1, and increased survival through TNFR2 and NF-κB activation. The NF-κB inhibitor SN-50 reestablished sensitivity to docetaxel in docetaxel-resistant MCF-7 cells. Gene-expression analysis of wild-type and docetaxel-resistant MCF-7, MDA-MB-231, and A2780 cells identified changes in the expression of TNF-α-related genes consistent with reduced TNF-induced cytotoxicity and activation of NF-κB survival pathways.

CONCLUSIONS

We report for the first time that taxanes can promote dose-dependent sTNF-α production in tumor cells at clinically relevant concentrations, which can contribute to their cytotoxicity. Defects in the TNF cytotoxicity pathway or activation of TNF-dependent NF-κB survival genes may, in contrast, contribute to taxane resistance in tumor cells. These findings may be of strong clinical significance.

Effects on quality of life, anti-cancer responses, breast conserving surgery and survival with neoadjuvant docetaxel: a randomised study of sequential weekly versus three-weekly docetaxel following neoadjuvant doxorubicin and cyclophosphamide in women with primary breast cancer

Background

Weekly docetaxel has occasionally been used in the neoadjuvant to downstage breast cancer to reduce toxicity and possibly enhance quality of life. However, no studies have compared the standard three weekly regimen to the weekly regimen in terms of quality of life. The primary aim of our study was to compare the effects on QoL of weekly versus 3-weekly sequential neoadjuvant docetaxel. Secondary aims were to determine the clinical and pathological responses, incidence of Breast Conserving Surgery (BCS), Disease Free Survival (DFS) and Overall Survival (OS).

Methods

Eighty-nine patients receiving four cycles of doxorubicin and cyclophosphamide were randomised to receive twelve cycles of weekly docetaxel (33 mg/m²) or four cycles of 3-weekly docetaxel (100 mg/m²). The Functional Assessment of Cancer Therapy-Breast and psychosocial questionnaires were completed.

Results

At a median follow-up of 71.5 months, there was no difference in the Trial Outcome Index scores between treatment groups. During weekly docetaxel, patients experienced less constipation, nail problems, neuropathy, tiredness, distress, depressed mood, and unhappiness. There were no differences in overall clinical response (93% vs. 90%), pathological complete response (20% vs. 27%), and breast-conserving surgery (BCS) rates (49% vs. 42%). Disease-free survival and overall survival were similar between treatment groups.

Conclusions

Weekly docetaxel is well-tolerated and has less distressing side-effects, without compromising therapeutic responses, Breast Conserving Surgery (BCS) or survival outcomes in the neoadjuvant setting.

Trial registration

ISRCTN: ISRCTN09184069