Phase II trial of paclitaxel by 3-hour infusion as initial and salvage chemotherapy for metastatic breast cancer

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.

Efficacy and safety of apatinib monotherapy for patients with advanced breast cancer: a systematic review and meta-analysis

Background

Patients with advanced breast cancer usually have poor prognosis. Apatinib is a small-molecule tyrosine kinase inhibitor, and the reports regarding the efficacy and safety of apatinib monotherapy for advanced breast cancer in the current literature are controversial. Therefore, we performed a systematic review and meta-analysis to collect and pool efficacy and safety data of apatinib monotherapy for advanced breast cancer with the aim of providing up-to-date evidence to aid clinical practice.

Methods

This study was registered at PROSPERO (CRD42020190049). Three literature databases, including PubMed, EMBASE, and Cochrane Library, were searched. For evaluating efficacy, the objective response rate and disease control rate were extracted or calculated. Safety was evaluated in terms of the proportions of patients with grade 3 or 4 treatment-related adverse events. The pooled proportions of the outcomes and their 95% confidence interval were shown. The Kaplan–Meier curves of overall survival and progression-free survival were pooled from the extracted data of the included studies. Furthermore, pooled medians for overall survival and progression-free survival were calculated. A p-value of < 0.05 was considered statistically significant.

Results

Six studies were included and deemed eligible for further quality evaluation and analysis. The pooled objective response rate and disease control rate were 20.4% and 71.6%, respectively. The pooled proportions of four hematologic adverse events ranged from 2.6% to 6.9%. The pooled proportions of hypertension, hand-foot syndrome, transaminase increased, and proteinuria ranged from 4.1% to 24.3%, and other non-hematologic adverse events were <1%. The pooled median progression-free survival and overall survival were 4.00 and 10.43 months, respectively, in cases of advanced breast cancer treated with apatinib.

Conclusions

This study confirms the reliable efficacy of apatinib monotherapy for advanced breast cancer. However, non-hematologic grade 3–4 adverse events, especially hypertension, are more frequently observed during apatinib treatment than during treatment with other tyrosine kinase inhibitors, such as sunitinib or sorafenib.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42020190049.

Outcome of patients with metastatic triple negative breast cancer treated with first-line chemotherapy: a single institution retrospective analysis

PURPOSE

Metastatic triple negative breast cancer (mTNBC) is associated with poor prognosis and limited treatment options. It is known to be high immunogenic, with a high level of programmed cell death-ligand 1 (PD-L1) expression. PD-L1 expression in TNBC does not have a clear prognostic relevance. In this study, we aimed to assess survival outcomes according to PD-L1 expression in the real world.

METHODS

We retrospectively analyzed mTNBC patients treated with first-line chemotherapy at European Institute of Oncology with evaluable PD-L1 expression. Primary endpoints were Progression-Free Survival (PFS) and Overall Survival (OS) according to PD-L1 expression.

RESULTS

From January 2000 to December 2018, 190 patients fulfilled the inclusion criteria for final analysis. PD-L1 positive (≥ 1%) subgroup showed a median PFS of 6.8 vs 5.6 months in PD-L1 negative subgroup (PFS-HR 1.25, 95% CI 0.89-1.74, p-value = 0.191), while at data cutoff we had 120 deaths in the PD-L1 < 1% population with a median OS of 22.1 months and 42 deaths in PD-L1 positive patients with a median OS of 20.8 months (OS-HR 1.09, 95% CI 0.76-1.55, p-value = 0.64). No difference in PFS and OS was related to the choice of chemotherapy (p-value for PFS: 0.19, p-value for OS: 0.53).

CONCLUSION

No differences in clinical outcome were found according to PD-L1 status or chemotherapy regimen chosen. In "unselected" patients, single agent or combination chemotherapy could be appropriate, although in the immunotherapy era patients with newly diagnosed mTNBC should be routinely tested for PD-L1 status. The variability in PD-L1 expression by metastatic site warrants further investigation.

Smart Polymeric Nanoparticles with pH-Responsive and PEG-Detachable Properties (II): Co-Delivery of Paclitaxel and VEGF siRNA for Synergistic Breast Cancer Therapy in Mice

Background

The dual-loaded nano-delivery system can realize chemotherapeutic drug and small interfering RNA (siRNA) co-loading as well as enhance the therapeutic effect of drugs on tumors through a synergistic effect, while reducing their toxic and side effects on normal tissues.

Methods

Previously, we developed layered smart nanoparticles (NPs) to co-deliver survivin siRNA as well as small molecule drugs for lung cancer. In this study, we used such smart NPs to co-deliver paclitaxel (PTX) and siRNA against vascular endothelial growth factor (VEGF) gene for breast cancer therapy in mice models. For the prepared NPs, characterizations such as particle size, zeta potential, gel electrophoresis imaging and in vitro stability were investigated. Then, 4T1 cells were used to evaluate the in vitro VEGF silencing capacity, tumor cell inhibitory and anti-apoptotic abilities. Finally, an orthotopic model of mouse breast cancer was established to evaluate the in vivo antitumor effects and safety properties of PTX-siRNA^VEGF-NPs.

Results

We prepared PTX-siRNA^VEGF-NPs with particle size of 85.25 nm, PDI of 0.261, and zeta potential of 5.25 mV. The NPs with VEGF siRNA effectively knocked down the expression of VEGF mRNA. Cell counting kit-8 (CCK-8) and apoptosis assays revealed that the PTX-siRNA^VEGF-NPs exhibited antiproliferation effect of PTX on 4T1 cells. The in vivo anti-tumor study indicated that PTX-siRNA^VEGF-NPs could exert an antitumor effect by inhibiting the formation and development of new blood vessels in tumor tissues, thereby cutting off nutrient and blood supplies required for tumor tissue growth. Both the anti-tumor efficacy and in vivo safety of the PTX-siRNA^VEGF-NPs group were better than that of the PTX-NPs and siRNA^VEGF-NPs groups.

Conclusion

The combination of PTX and VEGF siRNA exerts good antitumor effect on 4T1 tumor cells. This study provides a theoretical and practical basis for breast cancer therapy.

First in class dual MDM2/MDMX inhibitor ALRN-6924 enhances antitumor efficacy of chemotherapy in TP53 wild-type hormone receptor-positive breast cancer models

BACKGROUND

MDM2/MDMX proteins are frequently elevated in hormone receptor-positive (ER+) breast cancer. We sought to determine the antitumor efficacy of the combination of ALRN-6924, a dual inhibitor of MDM2/MDMX, with chemotherapy in ER+ breast cancer models.

METHODS

Three hundred two cell lines representing multiple tumor types were screened to confirm the role of TP53 status in ALRN-6924 efficacy. ER+ breast cancer cell lines (MCF-7 and ZR-75-1) were used to investigate the antitumor efficacy of ALRN-6924 combination. In vitro cell proliferation, cell cycle, and apoptosis assays were performed. Xenograft tumor volumes were measured, and reverse-phase protein array (RPPA), immunohistochemistry (IHC), and TUNEL assay of tumor tissues were performed to evaluate the in vivo pharmacodynamic effects of ALRN-6924 with paclitaxel.

RESULTS

ALRN-6924 was active in wild-type TP53 (WT-TP53) cancer cell lines, but not mutant TP53. On ER+ breast cancer cell lines, it was synergistic in vitro and had enhanced in vivo antitumor activity with both paclitaxel and eribulin. Flow cytometry revealed signs of mitotic crisis in all treatment groups; however, S phase was only decreased in MCF-7 single agent and combinatorial ALRN-6924 arms. RPPA and IHC demonstrated an increase in p21 expression in both combinatorial and single agent ALRN-6924 in vivo treatment groups. Apoptotic assays revealed a significantly enhanced in vivo apoptotic rate in ALRN-6924 combined with paclitaxel treatment arm compared to either single agent.

CONCLUSION

The significant synergy observed with ALRN-6924 in combination with chemotherapeutic agents supports further evaluation in patients with hormone receptor-positive breast cancer.

The Impact of Immunological Checkpoint Inhibitors and Targeted Therapy on Chronic Pruritus in Cancer Patients

Although pruritus may sometimes be a consequential situation to neoplasms, it more frequently emerges after commencing chemotherapy. In this review, we present our analysis of the chemotherapy treatments that most often induce skin changes and itching. After discussing conventional chemotherapies capable of inducing pruritus, we present our evaluation of new drugs such as immunological checkpoint inhibitors (ICIs), tyrosine kinase inhibitors, and monoclonal antibodies. Although ICIs and targeted therapy are thought to damage tumor cells, these therapies can modify homeostatic events of the epidermis and dermis, causing the occurrence of cutaneous toxicities in treated subjects. In the face of greater efficacy, greater skin toxicity has been reported for most of these drugs. A remarkable aspect of some reports is the presence of a probable correlation between cutaneous toxicity and treatment effectiveness in tumor patients who were treated with novel drugs such as nivolumab or pembrolizumab. Findings from these experiments demonstrate that the occurrence of any grade of skin side effects can be considered as a predictor of a better outcome. In the near future, studies on the relationship between the onset of skin alterations and outcomes could open new perspectives on the treatment of neoplasms through specific target therapy.

Cost-Effectiveness of Ribociclib for Hormone Receptor-Positive HER2-Negative Advanced Breast Cancer

PURPOSE

Ribociclib has provided significant improvements in progression-free survival (PFS) and overall survival (OS) of postmenopausal patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC). However, given the high cost of ribociclib, its value must be evaluated based on cost-effectiveness. Thus, we aimed to explore the cost-effectiveness of ribociclib for postmenopausal patients with HR-positive and HER2-negative ABC.

METHODS

A comprehensive Markov model was developed to estimate the cost-effectiveness of ribociclib plus fulvestrant versus placebo plus fulvestrant as first-line treatment for HR-positive, HER2-negative ABC. Variables were estimated based on data from the randomized Phase III MONALEESA-3 trial. Ten-year values were estimated for quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Direct treatment costs were estimated from the perspective of a United States payer. One-way and probabilistic sensitivity analyses were conducted to confirm the model's robustness.

RESULTS

Ribociclib plus fulvestrant increased the treatment cost by $382,172 and provided 0.47 QALYs, relative to fulvestrant alone, which corresponded to an ICER of $813,132 per QALY. Sensitivity analyses revealed that ribociclib was unlikely to be cost-effective even under the most favorable assumptions. When the cost of ribociclib was <$1,384, there was a >50% chance of cost-effectiveness at a willingness-to-pay threshold of $150,000/QALY. Subgroup analyses also confirmed that ribociclib was not cost-effective.

CONCLUSION

At current drug prices in the United States, ribociclib is unlikely to be cost-effective for treating postmenopausal patients with HR-positive HER2-negative ABC. Despite the clinical benefits of ribociclib, its cost would need to decrease to provide more favorable economic outcomes.

Novel formulations of docetaxel, paclitaxel and doxorubicin in the management of metastatic breast cancer

The management of breast cancer with advanced disease or metastasis is a common problem in India and other countries. A panel of 13 oncology experts deliberated on the sidelines of the 35th Indian Cooperative Oncology Network Conference held in Mumbai to formulate an expert opinion recommendation on the novel drug delivery system (NDDS) formulations in the treatment of metastatic breast cancer (MBC). The survey comprised of 39 questions related to limitations of conventional formulations and therapeutic positioning of NDDS formulations of docetaxel, paclitaxel and doxorubicin in the management of MBC. The experts used data from published literature and their practical experience to provide expert opinion and recommendations for use by the community oncologists. The experts opined that the newer NDDS formulations should provide a significant efficacy advantage in terms of overall survival and progression-free survival, or demonstrate better tolerability when compared with conventional formulations. The newer NDDS formulations of taxanes should be considered in special circumstances such as diabetes, in patients who have had hypersensitivity reactions and in cases where steroids need to be avoided. The novel formulations of doxorubicin should be used in the elderly and in patients with borderline cardiac function.

Paclitaxel Administered Weekly in Patients with Docetaxel-Resistant Metastatic Breast Cancer: A Single-Center Study

Aims and background

We evaluated retrospectively the efficacy and toxicity of paclitaxel in patients with docetaxel-resistant metastatic breast cancer.

Study design

Paclitaxel (80 mg/m2) was administered weekly to 44 patients who had previously received chemotherapy regimens for metastatic breast cancer. All patients had progressive disease in spite of having received docetaxel therapy.

Results

Treatment was repeated until there was evidence of disease progression. Objective responses were obtained in 14 of 44 assessable patients (31.8%; 95% confidence interval, 17.5–46.1). Fourteen patients had partial responses; none responded completely. Seven of 14 responders had primary resistance to docetaxel therapy. The median duration of response was 6.1 months (range, 2.1–12.7). The median time to progression was 5.0 months. Clinically severe adverse events (grade 3 or 4) included neutropenia (27.2%), leukopenia (25.0%), neuropathy-sensory (13.6%), febrile neutropenia (6.8%), anemia (2.2%), constipation (2.2%), and edema (2.2%). Treatment was generally well tolerated and could be continued on an out-patient basis.

Conclusions

Weekly paclitaxel is effective in patients with docetaxel-resistant metastatic breast cancer. This observation suggests partial cross-resistance between paclitaxel and docetaxel. There was no evidence for additive cumulative toxic effects of the two taxanes.

Salvage Treatment with Epirubicin and/or Paclitaxel in Metastatic Breast Cancer Patients Relapsed after High-dose Chemotherapy with Peripheral Blood Progenitor Cells

Aims and Background

To evaluate feasibility and efficacy of paclitaxel as a single agent or in combination with epirubicin in breast cancer taxane-naive patients who have failed previous high-dose chemotherapy.

Methods

Since February 1995, we have treated 32 patients in first relapse or progression after high-dose chemotherapy. Nineteen patients had metastatic breast cancer, 12 more than 3 involved axillary lymph nodes, and 1 inflammatory breast cancer at inclusion to the program. The median time to relapse after high-dose chemotherapy was 12 months (range, 2-43). At relapse, 12 patients were treated with epirubicin (90 mg/m2) plus paclitaxel (175 mg/m2) administered on day 1 every 21 days. In 20 patients who had previously received more than 350 mg/m2 of a cumulative dose of epirubicin and in one patient pretreated with chemotherapy containing mitoxantrone, we employed paclitaxel (175 mg/m2) alone. A median number of five courses was administered (range, 2-10).

Results

The overall response rate after 3 courses (29 of 32 patients were assessable) was 55% and after 6 courses (21 of 32 patients were assessable) was 57%. The median time to progression was 7 months (95% CI, 5.7-9.2), and median survival was 27.5 months (95% CI, 17.8-37.0). Toxicity was recorded for 180 cycles (epirubicin + paclitaxel for 62 cycles and paclitaxel alone for 118 cycles). The main toxicity in both regimens was hematologic. We observed WHO grade 3-4 neutropenia (in 8 patients, 25%), for which G-CSF (5 μg/kg/day sc) was employed. WHO grade 3-4 thrombocytopenia occurred in 2 patients (6%) and WHO grade 3 anemia in 1 patient (3%).

Conclusions

Our study showed that paclitaxel (alone or in combination with epirubicin) is feasible as salvage treatment in heavily pretreated patients.

Paclitaxel Activity in Anthracycline Refractory Breast Cancer Patients

Aims and background

We investigated the efficacy and tolerability of two doses of paclitaxel, 175 mg/m2 and 135 mg/m2, over a 3-hr infusion, without prophylactic G-CSF, in heavily pretreated patients with anthracycline-resistant breast cancer. Although paclitaxel may share with anthracyclines a common mechanism of drug resistance, there is evidence that the two drugs are not completely cross resistant.

Methods

From July 1994 to January 1996, 42 patients were treated every 3 weeks, for a maximum of 6 cycles; paclitaxel dose was established according to pretreatment extension.

Results

In 41 assessable patients we observed 9 partial responses, for an overall response rate of 22% (95% CI, 10–34%). There was no difference in response rate between the two dose levels. Median duration of response was 9 months, median time to progression 5 months, and median survival 9 months. The dose-limiting toxicity was neutropenia, which was grade 3–4 in 40% (135 mg/m2) and 62% (175 mg/m2) of the patients (P = 0.28); neutropenic fever occurred in 24% of the patients, without significant differences between the two dose levels. Other toxicity was mild to moderate.

Conclusions

Paclitaxel at doses of 175 mg/m2 or 135 mg/m2 is active and well tolerated in advanced breast cancer patients resistant to anthracyclines. The prophylactic use of colony-stimulating factors seems appropriate in heavily pretreated patients given the higher dose level.

Taxane-induced arthralgia and myalgia: A literature review

Purpose

Arthralgia and myalgia following taxane chemotherapy has been documented in the literature. However, these two toxicities associated with taxane treatment have not been closely examined in the literature, and data remain inconsistent in terms of the reported incidences of these toxicities. The purpose of this literature review was to provide a more comprehensive understanding of the incidence of taxane-induced arthralgia and myalgia, as well as to document the risk factors and preventative and therapeutic treatments that have been investigated.

Methods

A literature search was conducted in Ovid Medline, OldMedline, Embase, Embase Classic, and Cochrane Central Register of Controlled Trials using relevant subject headings and keywords such as: “arthralgia,” “myalgia,” “muscle pain,” “joint pain,” “taxane,” “chemotherapy,” “docetaxel,” “paclitaxel.”

Results

The reported incidences of arthralgia and myalgia were variable. Taxane chemotherapy was found to be associated with greater incidences of arthralgia and myalgia than non-taxane forms of chemotherapy. Moreover, docetaxel and nab-paclitaxel seem to be associated with lower incidences of arthralgia and myalgia than paclitaxel. Finally, the literature on prevention and therapeutic treatment of taxane-induced arthralgia and myalgia is scarce.

Conclusion

More studies should be done in order to more conclusively identify optimal therapeutic and preventative treatments as well as different risk factors. We recommend that a prospective study be done in order to better understand the true incidence of arthralgia and myalgia in patients being treated with the paclitaxel, docetaxel, and nab-paclitaxel.

Paclitaxel impairs adipose stem cell proliferation and differentiation

BACKGROUND

Cancer patients with chemotherapy-induced immunosuppression have poor surgical site wound healing. Prior literature supports the use of human adipose-derived stem cell (hASC) lipoinjection to improve wound healing. It has been established that multipotent hASCs facilitate neovascularization, accelerate epithelialization, and quicken wound closure in animal models. Although hASC wound therapy may benefit surgical cancer patients, the chemotherapeutic effects on hASCs are unknown. We hypothesized that paclitaxel, a chemotherapeutic agent, impairs hASC growth, multipotency, and induces apoptosis.

METHODS

hASCs were isolated and harvested from consented, chemotherapy and radiation naive patients. Growth curves, MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide), and EdU (5-ethynyl-2-deoxyguridine) assays measured cytotoxicity and proliferation. Oil Red O stain, Alizarin Red stain, matrigel tube formation assay, and quantitative polymerase chain reaction analyzed hASC differentiation. Annexin V assay measured apoptosis. Immunostaining and Western blot determined tumor necrosis factor α (TNF-α) expression.

RESULTS

hASCs were selectively more sensitive to paclitaxel (0.01-30 μM) than fibroblasts (P < 0.05). After 12 d, paclitaxel caused hASC growth arrest, whereas control hASCs proliferated (P = 0.006). Paclitaxel caused an 80.6% reduction in new DNA synthesis (P < 0.001). Paclitaxel severely inhibited endothelial differentiation and capillary-like tube formation. Differentiation markers, lipoprotein lipase (adipogenic), alkaline phosphatase (osteogenic), CD31, and van Willebrand factor (endothelial), were significantly decreased (all P < 0.05) confirming paclitaxel impaired differentiation. Paclitaxel was also found to induce apoptosis and TNF-α was upregulated in paclitaxel-treated hASCs (P < 0.001).

CONCLUSIONS

Paclitaxel is more cytotoxic to hASCs than fibroblasts. Paclitaxel inhibits hASC proliferation, differentiation, and induces apoptosis, possibly through the TNF-α pathway. Paclitaxel's severe inhibition of endothelial differentiation indicates neovascularization disruption, possibly causing poor wound healing in cancer patients receiving chemotherapy.

Quantitative optical imaging of primary tumor organoid metabolism predicts drug response in breast cancer

There is a need for technologies to predict the efficacy of cancer treatment in individual patients. Here, we show that optical metabolic imaging of organoids derived from primary tumors can predict the therapeutic response of xenografts and measure antitumor drug responses in human tumor-derived organoids. Optical metabolic imaging quantifies the fluorescence intensity and lifetime of NADH and FAD, coenzymes of metabolism. As early as 24 hours after treatment with clinically relevant anticancer drugs, the optical metabolic imaging index of responsive organoids decreased (P < 0.001) and was further reduced when effective therapies were combined (P < 5 × 10(-6)), with no change in drug-resistant organoids. Drug response in xenograft-derived organoids was validated with tumor growth measurements in vivo and staining for proliferation and apoptosis. Heterogeneous cellular responses to drug treatment were also resolved in organoids. Optical metabolic imaging shows potential as a high-throughput screen to test the efficacy of a panel of drugs to select optimal drug combinations. Cancer Res; 74(18); 5184-94. ©2014 AACR.

Chemotherapy dose reduction due to chemotherapy induced peripheral neuropathy in breast cancer patients receiving chemotherapy in the neoadjuvant or adjuvant settings: a single-center experience

Purpose

Taxanes are a cornerstone treatment in early and advanced stage breast cancer and in other common solid tumor malignancies; however, the development of chemotherapy induced peripheral neuropathy (CIPN) often necessitates dose-reduction, which may hamper the effectiveness of the drug and compromise survival outcomes especially when used in the adjuvant setting. Limited literature is available on the prevalence and severity of dose reduction due to CIPN. We sought to determine the frequency and severity of CIPN-induced dose reduction in early stage breast cancer patients who received taxane-based chemotherapy in the neoadjuvant or adjuvant settings.

Methods

We conducted a retrospective single-institution breast cancer clinic chart review of 123 newly diagnosed breast cancer patients and treated with taxane-based neoadjuvant/adjuvant chemotherapy at the University of Maryland Greenebaum Cancer Center between January 2008 and December 2011.

Results

Forty-nine of 123 (40%; 95% CI: 31-49%) patients required dose reduction. Twenty-one (17%; 95% CI: 11-25%) of these patients were dose-reduced specifically due to CIPN that developed during treatment. The median relative dose intensity (received dose/planned dose) for the 21 CIPN-induced dose reduction patients was 73.4% (range, 68.0-94.0%). Patients with diabetes appeared to have a higher risk of taxane-induced dose reduction (p-value=0.01). African-American patients and those treated with paclitaxel (rather than docetaxel) experienced a higher-risk of CIPN-induced dose reduction (p-values are <0.001 and 0.001, respectively).

Conclusions

The incidence of CIPN-associated dose reduction in our patient population was 17%. African-American patients, diabetics and subjects treated with paclitaxel had a higher risk for CIPN-associated dose reduction in our study.

Full Dose Paclitaxel Plus Vinorelbine as Salvage Chemotherapy in Anthracycline-Resistant Advanced Breast Cancer: A Phase II Study

This phase II trial studied the efficacy and toxicity of full dose paclitaxel plus vinorelbine, as salvage chemotherapy in patients with metastatic breast cancer resistant to anthracyclines. Patients received vinorelbine (30 mg/m2) followed 1 hour later by full dose paclitaxel (175 mg/m2) every 3 weeks for a maximum of 8 cycles or until disease progression. Because of the heavy pretreatment of the patients, prophylactic granulocyte-colony stimulating factor (5 microg/kg) was administered daily for 5-10 days. To minimize potentially cumulative neurotoxicity due to both agents, amifostine was given prior to chemotherapy. Thirty-four patients: 8 with tumors primary resistant and 26 with tumors recurring within 3-6 months after anthracycline treatment, were evaluable for efficacy and toxicity. Objective responses occurred in 11 patients [32%; 95% confidence interval (CI): 16.3-47.7%), all partial responses. Responses were observed in lung and liver. The median response duration was 4 months (range 3-7), median time to progression was 5 months (range 3-9) and median overall survival was 8 months (range 4-24). Neutropenia was dose limiting (35% grade 3-4 toxicity). The left ventricular ejection fraction, measured and followed in 18 patients, fell less than 20% below baseline level in 9 patients (50%), but only one patient developed congestive cardiac failure. The paclitaxel-vinorelbine regimen was moderately tolerated and moderately effective in poor prognosis breast cancer patients with visceral metastases and tumors resistant to anthracyclines. The combination at these doses and schedules should be considered in the design of regimens for advanced breast cancer.

Capecitabine plus paclitaxel versus epirubicin plus paclitaxel as first-line treatment for metastatic breast cancer: efficacy and safety results of a randomized, phase III trial by the AGO Breast Cancer Study Group

Capecitabine/taxane combinations are highly active in metastatic breast cancer (MBC). We conducted a randomized, phase III, noninferiority trial comparing capecitabine plus paclitaxel (XP) with epirubicin plus paclitaxel (EP) as first-line therapy for MBC, regarding progression-free survival (PFS) as primary efficacy endpoint. Females who had received no prior chemotherapy for MBC were randomized to six 3-weekly cycles of XP (capecitabine 1000 mg/m(2) b.i.d., days 1-14; paclitaxel 175 mg/m(2) 3-h infusion, day 1) or EP (epirubicin 60 mg/m(2) 1-h infusion, day 1; paclitaxel as above). Secondary endpoints included response rate, overall survival, tolerability, and quality of life (QoL). Each arm included 170 patients, most of whom received all six cycles as planned. The difference in means of (logarithmic) PFS times (-0.205) did not meet the pre-defined level for noninferiority (-0.186). However, PFS was similar in the two arms [HR: XP vs. EP: 1.012 (95 % CI 0.785-1.304); median 10.4 months XP vs. 9.2 months EP]. Overall survival was also similar [HR 1.027 (95 % CI 0.740-1.424); median 22.0 vs. 26.1 months], and response rate was 47 % versus 42 %. Both regimens were tolerable: there were more grade 3/4 diarrhea and grade 3 hand-foot syndromes with XP and more grade 3/4 hematologic toxicities with EP. There were no major differences in QoL. Although, noninferiority of XP to EP was formally not proven, first-line XP was active and feasible. XP is a valid first-line alternative to anthracycline/taxane regimens, especially in patients previously treated with adjuvant anthracyclines.

Higher rate of skin rash in a phase II trial with weekly nanoparticle albumin-bound paclitaxel and cisplatin combination in Chinese breast cancer patients

Abstracts

Nab-paclitaxel for first-line treatment of patients with metastatic breast cancer and poor prognostic factors: a retrospective analysis

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) has demonstrated clinical benefit in metastatic breast cancer (MBC) in a randomized phase III trial versus paclitaxel (CA012; N = 454) and in a randomized phase II trial versus docetaxel (CA024; N = 300). This retrospective analysis examines whether patients with poor prognostic factors demonstrate similar outcomes to the intent-to-treat (ITT) populations in these trials. This retrospective analysis evaluated the efficacy and safety of previously untreated patients with MBC with the following poor prognostic factors: visceral dominant metastases and short disease-free interval (DFI; ≤2 years). In CA012 (n = 186 first-line patients), nab-paclitaxel demonstrated a significantly higher overall response rate (ORR) versus paclitaxel in patients with visceral dominant metastases (42 vs. 23 %; P = 0.022), whereas the higher ORR for nab-paclitaxel in patients with a short DFI (43 vs. 33 %; P = NS) was not statistically significant. In CA024, a significantly higher ORR for nab-paclitaxel 150 mg/m² versus docetaxel was observed in patients with visceral dominant metastases (76 vs. 37 %; P < 0.001). No significant differences in ORR were observed in patients with a short DFI. Although progression-free survival (PFS) and overall survival showed trends similar to ORR, statistical significance was only achieved for comparisons of PFS in patients with visceral dominant metastases in CA024 (13.1 months for nab-paclitaxel 150 mg/m² vs. 7.8 months for docetaxel [P = 0.019] and 7.5 months for nab-paclitaxel 100 mg/m² [P = 0.010]). Safety results were similar to previous reports of the ITT populations. nab-Paclitaxel demonstrated similar efficacy in patients with poor prognostic factors as in the ITT populations of these two trials. In each trial, ORR was significantly higher for nab-paclitaxel versus the comparator taxane among patients with visceral dominant metastases.

Taxanes for the treatment of metastatic breast cancer

Taxanes have remained a cornerstone of breast cancer treatment over the past three decades, improving the lives of patients with both early- and late-stage disease. The purpose of this review is to summarize the current role of taxanes, including an albumin-bound formulation that enhances delivery of paclitaxel to tumors, in the management of metastatic breast cancer (MBC). Since the introduction of Cremophor EL-paclitaxel to the clinic in the mid-1990s, a substantial amount of investigation has gone into subjects such as formulation, dose, schedule, and taxane resistance, allowing physicians greater flexibility in treating patients with MBC. This review will also examine how the shrinking pool of taxane-naive patients, a result of the expansion of taxanes into the neoadjuvant and adjuvant settings, will respond to taxane retreatment for metastatic disease. Taxane treatment seems likely to continue to play an important role in the treatment of MBC.

Whole-genome studies identify solute carrier transporters in cellular susceptibility to paclitaxel

OBJECTIVE

The clinical use of paclitaxel is limited by variable responses and the potential for significant toxicity. To date, studies of associations between variants in candidate genes and paclitaxel effects have yielded conflicting results. We aimed to evaluate the relationships between global gene expression and paclitaxel sensitivity.

METHODS

We utilized well-genotyped lymphoblastoid cell lines derived from the International HapMap Project to evaluate the relationships between cellular susceptibility to paclitaxel and global gene expression. Cells were exposed to varying concentrations of paclitaxel to evaluate paclitaxel-induced cytotoxicity and apoptosis. Among the top genes, we identified solute carrier (SLC) genes associated with paclitaxel sensitivity and narrowed down the list to those that had single nucleotide polymorphisms associated with both the expression level of the SLC gene and also with paclitaxel sensitivity. We performed an independent validation in an independent set of cell lines and also conducted functional studies using RNA interference.

RESULTS

Of all genes associated with paclitaxel-induced cytotoxicity at P less than 0.05 (1713 genes), there was a significant enrichment in SLC genes (31 genes). A subset of SLC genes, namely SLC31A2, SLC43A1, SLC35A5, and SLC41A2, was associated with paclitaxel sensitivity and had regulating single nucleotide polymorphisms that were also associated with paclitaxel-induced cytotoxicity. Multivariate modeling demonstrated that those four SLC genes together explained 20% of the observed variability in paclitaxel susceptibility. Using RNA interference, we demonstrated increased paclitaxel susceptibility with knockdown of three SLC genes, SLC31A2, SLC35A5, and SLC41A2.

CONCLUSION

Our findings are novel and lend further support to the role of transporters, specifically solute carriers, in mediating cellular susceptibility to paclitaxel.

Current approaches to the management of Her2-negative metastatic breast cancer

While metastatic breast cancer (MBC) remains incurable, a vast array of active therapeutic agents has provided the opportunity for long-term disease control while maintaining quality of life and physical function. Optimal management of MBC balances a multitude of factors, including a woman's performance status, social support, symptoms, disease burden, prior therapies, and surrogates for tumor biology. Choosing the most appropriate initial therapy and subsequent sequence of treatments demands flexibility as goals and patient preferences may change. Knowledge of the estrogen receptor (ER), progesterone receptor (PR), and Her2 receptor status of the metastatic tumor has become critical to determining the optimal treatment strategy in the metastatic setting as targeted therapeutic approaches are developed. Patients with ER⁺ or PR⁺ breast cancer or both have a wide array of hormonal therapy options that can forestall the use of cytotoxic therapies, although rapidly progressive phenotypes and the emergence of resistance may ultimately lead to the need for chemotherapy in this setting. So-called 'triple-negative' breast cancer - lacking ER, PR, and Her2 overexpression - remains a major challenge. These tumors have an aggressive phenotype, and clear targets for therapy have not yet been established. Chemotherapy remains the mainstay of treatment in this group, but biologically based clinical trials of new agents are critical to developing a more effective set of therapies for this patient population.

Capecitabine and weekly paclitaxel as first-line therapy in Thai patients with metastatic breast cancer

AIM

The combination of a taxane and capecitabine offers synergistic antitumor activity. This study aimed to determine the efficacy and tolerability of a paclitaxel and capecitabine combination in Thai patients with metastatic breast cancer (MBC) not previously treated for metastatic disease.

METHODS

This open-label, single-center, non-comparative phase II study was conducted between December 2006 and March 2009. In all 40 MBC patients were treated with oral capecitabine 1000 mg/m(2) twice daily on days 1 to 14, and weekly paclitaxel 80 mg/m(2) in a 3-week cycle for a total of six cycles.

RESULTS

After a median follow up of 13.4 months, an overall objective response rate of 80%, with a partial response of 74% and a complete response of 5% were achieved. While 8% of patients achieved stable disease, 13% had progressive disease. Median time to progress was 8 months and median overall survival was 24.4 months. One patient discontinued because of hypersensitivity to paclitaxel. There was no grade 4 toxicity. Skin and nail toxicity was found in 75% of patients (with 25% in grade 2 or 3), followed by neutropenia (45% in all with 15% in grades 2 or 3), neuropathy (25% in total with 5% in grade 2) and stomatitis and diarrhea (in both of which 5% experienced grade 1 severity).

CONCLUSION

A first-line regimen of weekly paclitaxel plus capecitabine is effective and tolerable in Thai MBC patients.

Antitumor activity and molecular dynamics simulations of paclitaxel-laden triazine dendrimers

The antitumor activities of triazine dendrimers bearing paclitaxel, a well-known mitotic inhibitor, are evaluated in SCID mice bearing human prostate cancer xenografts. To increase the activity of a first generation prodrug 1 that contained twelve paclitaxel molecules tethered via an ester linkage, the new construct described here, prodrug 2, tethers paclitaxel with linkers containing both an ester and disulfide. While PEGylation is necessary for solubility, and may improve biocompatibility and increase plasma half-life, it increases the heterogeneity of the sample with an average of eight to nine PEG chains (2 kDa each) incorporated. The heterogeneous population of PEGylated materials was used without fractionation based on models obtained from molecular dynamics simulations. Three models were examined; hexaPEGylated, nonaPEGylated, and dodecaPEGylated constructs. Intravenous delivery of prodrug 2 was performed by single, double or triple dosing regimes with doses spaced by one week. The doses varied from 50 mg of paclitaxel/kg to 200 mg of paclitaxel/kg. Tumor growth arrest and regression was observed over the 10-week treatment period without mortality for mice treated with the 50 mg of paclitaxel/kg treated three times.

Weekly Paclitaxel plus Capecitabine versus Docetaxel Every 3 Weeks plus Capecitabine in Metastatic Breast Cancer

Background. We performed a randomized phase II study comparing efficacy and toxicity of weekly paclitaxel 80 mg/m(2) (Weetax) with three weekly docetaxel 75 mg/m(2) (Threetax), both in combination with oral capecitabine 1000 mg/m(2) twice daily for 2 weeks followed by a 1-week break. Patients. Thirty-seven women with confirmed metastatic breast cancer were randomized. Results. Median TTF was 174 (Weetax) versus 147 days (Threetax) (P=0.472). Median OS was 933 (Weetax) versus 464 days (Threetax) (P=0.191). Reasons for TTF were PD 8/18 (Weetax), 9/19 (Threetax); and toxicity: 8/18 (Weetax), 8/19 (Threetax). ORR was 72% (Weetax) versus 26% (Threetax) (P = 0.01). The Threetax-combination resulted in a higher incidence of leuco-/neutropenia compared to Weetax. Grade II anemia was more pronounced in the Weetax group. No difference was found in quality of life. Conclusion. Taxanes in combination with capecitabine resulted in a high level of toxicity. Taxanes and capecitabine should be considered given sequentially and not in combination.

Clinical trials in the era of personalized oncology

The rapid pace of discoveries in tumor biology, imaging technology, and human genetics hold promise for an era of personalized oncology care. The successful development of a handful of new targeted agents has generated much hope and hype about the delivery of safer and more effective new treatments for cancer. The design and conduct of clinical trials has not yet adjusted to a new era of personalized oncology and so we are more in transition to that era than in it. With the development of treatments for breast cancer as a model, we review the approaches to clinical trials and the development of novel therapeutics in the prior era of population oncology, the current transitional era, and the future era of personalized oncology.

Clinical presentation and management of hand-foot skin reaction associated with sorafenib in combination with cytotoxic chemotherapy: experience in breast cancer

Current combination therapies for advanced breast cancer provide a modest survival benefit but with greater toxicity than with monotherapies. New combinations are needed that improve the efficacy of current treatments and have acceptable tolerability profiles. Recent clinical trials have assessed the efficacy and safety of the multikinase inhibitor sorafenib in combination with common treatments for advanced breast cancer. Sorafenib has both antiangiogenic and antiproliferative activities and is indicated for patients with unresectable hepatocellular and advanced renal cell carcinoma. Generally, sorafenib is associated with manageable, non-life-threatening adverse events. One of the more common adverse events seen with sorafenib is hand-foot skin reaction, a dermatologic toxicity usually localized to the pressure points of the palms and soles. Although hand-foot skin reaction is reversible and not life threatening, it can have a significant impact on a patient's quality of life and may necessitate dose modification. Moreover, sorafenib is being evaluated in combination with breast cancer treatments that are associated with a similar dermatologic toxicity (e.g., capecitabine-induced hand-foot syndrome). This review looks at the use of sorafenib in combination with selected chemotherapies in patients with advanced breast cancer and considers the incidence, prevention, and management of hand-foot skin reaction.

Weekly docetaxel in the treatment of metastatic breast cancer

Breast cancer is the most frequent tumor among women worldwide and is the second cause of cancer-related mortality in the US. Metastatic breast cancer (MBC) accounts for less than 10% of newly diagnosed breast cancer patients and about 30% of early breast cancer patients will develop recurrent, advanced, or metastatic disease. It remains an incurable illness and the primary goal of its management is palliative. Several agents are active for the first-line treatment of MBC. The taxanes, paclitaxel and docetaxel, represent the standard of care for the treatment of these patients. Among the various schedules, docetaxel can be administered weekly, achieving similar efficacy results with lower toxicity compared with conventional schedules. Weekly docetaxel (25–40 mg/m²) has been widely tested in several phase I and II studies both as a single agent and in multichemotherapy regimens, reaching overall response rates ranging from 26% and 86% or 20% and 73% with docetaxel alone or in combination, respectively, depending on doses, associations, and line of treatment. Overall, published data support the administration of weekly docetaxel for the treatment of MBC patients even if data from phase III randomized trials are still lacking.

Peripheral neuropathy with microtubule-targeting agents: occurrence and management approach

Microtubule-targeting agents (MTAs), which include vinca alkaloids, taxanes, and the recently introduced epothilone, ixabepilone, are widely used chemotherapeutic agents for treatment of patients with cancer. MTAs interfere with the normal structure and function of microtubules, leading to cell-cycle arrest and tumor cell death. Microtubule function is critical to normal neuronal function, thus MTA therapy is commonly associated with some form of neuropathy. There is poor agreement between tools for clinical assessment of MTA-associated peripheral neuropathy, and standardization of grading scales is needed to reduce variability. For a majority of patients, MTA-associated neuropathy is mild to moderate in intensity and reversible, but it can be severe and resolve incompletely. The incidence and severity of MTA-associated neuropathy is drug, dose, and schedule dependent. The first-generation vinca alkaloids (eg, vincristine) are associated with severe mixed sensory and motor neuropathy, whereas the newer vinca alkaloids (eg, vinorelbine, vinflunine) induce a milder sensory neuropathy. Taxane-associated sensory neuropathy occurs more often with standard (polyoxyethylated castor oil-based) and albumin-bound paclitaxel than with docetaxel. The incidence and presentation of peripheral neuropathy with ixabepilone, alone or in combination with capecitabine, are similar to that with taxanes. Management of neuropathy may involve reducing or delaying the MTA dose, or in severe persistent or disabling cases discontinuing treatment. Reversal of neuropathy after dosage intervention appears to be more rapid with ixabepilone than with other MTAs.

Sunitinib plus paclitaxel versus bevacizumab plus paclitaxel for first-line treatment of patients with advanced breast cancer: a phase III, randomized, open-label trial

INTRODUCTION

A multicenter, open-label phase III study was conducted to test whether sunitinib plus paclitaxel prolongs progression-free survival (PFS) compared with bevacizumab plus paclitaxel as first-line treatment for patients with HER2(-) advanced breast cancer.

PATIENTS AND METHODS

Patients with HER2(-) advanced breast cancer who were disease free for ≥ 12 months after adjuvant taxane treatment were randomized (1:1; planned enrollment 740 patients) to receive intravenous (I.V.) paclitaxel 90 mg/m(2) every week for 3 weeks in 4-week cycles plus either sunitinib 25 to 37.5 mg every day or bevacizumab 10 mg/kg I.V. every 2 weeks. [corrected]

RESULTS

The trial was terminated early because of futility in reaching the primary endpoint as determined by the independent data monitoring committee during an interim futility analysis. At data cutoff, 242 patients had been randomized to sunitinib-paclitaxel and 243 patients to bevacizumab-paclitaxel. Median PFS was shorter with sunitinib-paclitaxel (7.4 vs. 9.2 months; hazard ratio [HR] 1.63 [95% confidence interval (CI), 1.18-2.25]; 1-sided P = .999). At a median follow-up of 8.1 months, with 79% of sunitinib-paclitaxel and 87% of bevacizumab-paclitaxel patients alive, overall survival analysis favored bevacizumab-paclitaxel (HR 1.82 [95% CI, 1.16-2.86]; 1-sided P = .996). The objective response rate was 32% in both arms, but median duration of response was shorter with sunitinib-paclitaxel (6.3 vs. 14.8 months). Bevacizumab-paclitaxel was better tolerated than sunitinib-paclitaxel. This was primarily due to a high frequency of grade 3/4, treatment-related neutropenia with sunitinib-paclitaxel (52%) precluding delivery of the prescribed doses of both drugs.

CONCLUSION

The sunitinib-paclitaxel regimen evaluated in this study was clinically inferior to the bevacizumab-paclitaxel regimen and is not a recommended treatment option for patients with advanced breast cancer.

Weekly paclitaxel combining with gemcitabine is an effective and safe treatment for advanced breast cancer patients

OBJECTIVE

Patients with metastatic breast cancer usually accept several lines of chemotherapy. This retrospective study is to analyze the therapeutic effect and tolerance of weekly paclitaxel/gemcitabine combination on patients with metastatic breast cancer.

METHODS

Paclitaxel 80 mg/m(2) and gemcitabine 800 mg/m(2) were administered sequentially on days 1, 8 and 15 every 28 days. Patients with measurable metastatic breast cancer or locally advanced breast cancer were included.

RESULTS

From March 2005 to December 2006, 50 patients received this treatment at Chang Gung Memorial Hospital, Kaohsiung Medical Center. Thirteen (26%) patients accepted this regimen as their first-line treatment for metastatic breast cancer and 25 (50%) patients accepted this regimen after at least three lines of therapies for metastatic breast cancer. The overall response rate was 56% (95% confidence interval: 42.2-69.8%), 2 patients achieved complete response and 26 patients (52, 95% confidence interval: 38.2-65.9%) achieved partial response. The median progression free survival was 7.4 months (95% confidence interval: 5.5-9.3 months), and the median overall survival was 19.0 months (95% confidence interval: 9.7-28.3 months). Except alopecia, the most common Grade 3/4 toxicities were anemia and leucopenia; the incidences of both were fewer than 10%.

CONCLUSIONS

The combination of weekly gemcitabine and paclitaxel in patients with advanced breast cancer showed acceptable outcome and excellent toxic profiles. This therapeutic benefit could be achieved in any linage of patients with good performance status; earlier usage of this regimen can provide better result.

Management of metastatic breast cancer: monotherapy options for patients resistant to anthracyclines and taxanes

Resistance to chemotherapeutic agents is a significant obstacle to the effective treatment of metastatic breast cancer (MBC). Anthracycline- and taxane-based regimens are active as first-line treatment for MBC; however, MBC often progresses because of primary or acquired resistance to anthracyclines and taxanes. There are few options for the treatment of patients with anthracycline- and taxane-resistant or taxane-refractory MBC. This article reviews several single agents that have demonstrated activity as treatment for patients with MBC who progress during, or rapidly following, treatment with anthracyclines and taxanes. Results from clinical trials evaluating agents such as ixabepilone, albumin-bound paclitaxel, capecitabine, vinorelbine, pemetrexed, and irinotecan are presented. Single-agent capecitabine is approved for the treatment of patients after failure of anthracyclines and taxanes. Ixabepilone has demonstrated efficacy in patients with MBC resistant to multiple chemotherapeutic agents and is the only agent approved by the Food and Drug Administration as monotherapy for anthracycline-, taxane-, and capecitabine-resistant MBC. Improved treatment strategies and further evaluation of newer agents may reduce the current burden of treatment-resistant or treatment-refractory MBC.

Predictive and prognostic values of tau and ERCC1 in advanced breast cancer patients treated with paclitaxel and cisplatin

OBJECTIVE

We studied tau and excision repair cross-complementing 1 expression to evaluate their predictive values in advanced breast carcinoma patients.

METHODS

Patients treated with paclitaxel and cisplatin as the first-line chemotherapy for locally advanced or metastatic breast cancer were enrolled. The expression levels of tau and excision repair cross-complementing 1 were assessed by immunohistochemistry and examined for their associations with treatment response and survival.

RESULTS

Fifty-four patients were included in this study. Despite the strong association between tau expression and lower histological grade and estrogen receptor expression, tau expression remained an independent predictor for a lower response rate in multivariate analysis (odd ratio = 0.24, P = 0.02). However, tau expression was a predictor for longer overall survival in both univariate analysis (median, 57.5 vs. 30.4 months, P = 0.02) and multivariate analysis (hazard ratio = 0.36, P = 0.008). Excision repair cross-complementing 1 was not associated with treatment response or overall survival.

CONCLUSIONS

Tau expression but not excision repair cross-complementing 1 in advanced breast cancer predicts poor response to combination chemotherapy of paclitaxel and cisplatin. However, tau expression is significantly associated with longer overall survival.

Therapeutic options for metastatic breast cancer

Metastatic breast cancer (MBC) remains an incurable disease despite ongoing therapeutic advances. Recently there has been progress extending the range of available cytotoxic chemotherapy drugs and optimizing their scheduling. In addition, a greater understanding of tumor biology has led to the development of a number of targeted therapies. Several of these newer agents, such as trastuzumab, lapatinib and bevacizumab, have demonstrated activity in combination with chemotherapy and have improved the prognosis of patients with MBC. We hope that further progress elucidating the pathophysiology and biology of MBC will continue to lead to corresponding advances in treatment.

Paclitaxel and docetaxel in the treatment of breast cancer

BACKGROUND

Paclitaxel and docetaxel are considered fundamental drugs in the treatment of breast cancer.

OBJECTIVES

To review the current role of taxanes in the treatment breast cancer, with emphasis on data from randomized trials comparing the two taxanes.

METHODS

We have reviewed the available evidence in the literature to gauge the results of therapy of early and advanced breast cancer with taxanes.

RESULTS

Clinically benefits were first shown in metastatic setting. More recently, benefits have also been seen in the therapy of early-stage disease. It seems reasonable to consider either drug as standard treatment for node-positive early stage or metastatic breast cancer. Future studies should explore the optimal way of combining taxanes with novel biological and cytotoxic drugs.

CONCLUSION

Based on existing evidence, clinicians should choose a taxane-based regimen for their patients, according to clinical activity, toxicity profile, pharmacokinetics, and a dosing schedule that best meets the therapeutic needs and convenience.

Phase II trial of vinorelbine and trastuzumab in patients with HER2-positive metastatic breast cancer. A prospective, open label, non-controlled, multicenter phase II trial (to investigate efficacy and safety of this combination chemotherapy)

The purpose of this study was to evaluate the efficacy (progression free survival (PFS) and response rate) and safety of vinorelbine and trastuzumab combination chemotherapy in patients with HER2-overexpressing, metastatic breast cancer as a first line chemotherapy regimen. Patients with histologically confirmed, HER2-positive (immunohistochemistry (ICH) 3+, or 2+ and FISH+) metastatic breast cancer who had nor received prior vinorelbine or anti-HER2 therapy in the adjuvant setting, received at least eight weeks of vinorelbine i.v. (25 mg/g weekly) and trastuzumab (4 mg/kg on day 1 followed by 2 mg/kg weekly). Forty-one women from six participating centers were enrolled into the trial. The overall response rate, was 43.9% (18 of 41 patients), (CI 28-60.3%), 30% of patients were progression free after 1 year. Four patients reached complete remission, 14 partial remission and five had stable disease for at least 18 weeks. Six patients developed primary progression. 35 patients (85%) experienced progression after a median time of 235 days. Therapy was in general well-tolerated. There were two CTC grade 4 infusion syndromes and two patients experienced cardiotoxicity at least grade 2. This phase II trial of vinorelbine and trastuzumab demonstrated an effective and well-tolerated regimen with a favourable safety profile.

Ixabepilone: a new microtubule-targeting agent for breast cancer

Results of clinical trials over the past 15 years demonstrate that the taxanes are among the most effective new class of cytotoxic drugs to treat breast cancer and other solid tumors. Moreover, the efficacy of the taxanes added further credence to the relevance of the microtubule as a tumor target. In spite of the significant benefits observed in early and advanced breast cancer, a number of factors contribute to disease relapse and, perhaps more discouragingly, disease refractoriness. After exhausting cytotoxic chemotherapy, hormonal therapy, and other molecular-based-therapies, patients whose tumors exhibit taxane resistance had virtually no additional options. This paper, a product of the ongoing advances in the treatment of breast cancer, reviews two important areas: first, molecular concepts and relevance of the microtubule in breast cancer and second, clinical implications of ixabepilone, a novel, nontaxane tubulin-stabilizing agent in patients with taxane-resistant breast cancer.

Protein nanoparticles as drug carriers in clinical medicine

Solvent-based delivery vehicles for chemotherapy agents have been instrumental in providing a means for hydrophobic agents to be administered intravenously. These solvents, however, have been associated with serious and dose-limiting toxicities. Solvent-based formulations of taxanes, a highly active class of cytotoxic agents, are associated with hypersensitivity reactions, neutropenia, and neuropathy. Nanoparticle technology utilizing the human protein albumin exploits natural pathways to selectively deliver larger amounts of drug to tumors while avoiding some of the toxicities of solvent-based formulations. 130 nM albumin-bound (nab) paclitaxel (nab-paclitaxel; Abraxane) was recently approved for use in patients with metastatic breast cancer who have failed combination therapy. In a randomized, phase III study in metastatic breast cancer, nab-paclitaxel was found to have improved efficacy and safety compared with conventional, solvent-based paclitaxel. Preliminary data also suggest roles for nab-paclitaxel as a single agent and in combination therapy for first-line treatment of metastatic breast cancer as well as in other solid tumors, including non-small-cell lung cancer, ovarian cancer, and malignant melanoma. The nab technology promises to have broad utility in cancer therapy, and clinical trials are underway using nab formulations of other water-insoluble anticancer agents such as docetaxel and rapamycin.

Weekly epirubicin and paclitaxel with granulocyte colony-stimulating factor support in previously untreated metastatic breast cancer patients: a phase II study

We conducted a phase II study to determine the activity and tolerability of weekly epirubicin-paclitaxel and granulocyte colony-stimulating factor in breast cancer patients untreated for metastatic disease. The phase II study was designed following the Simon optimal-two stage method. Patients received epirubicin 25 mg/m and paclitaxel 80 mg/m every week, and granulocyte colony-stimulating factor on days 2 and 4 for 24 consecutive weeks in the absence of progression. From 1999 to 2004, 53 patients entered the study; 1093 weekly courses were delivered, with a median number of cycles of 22. Patients received a median relative dose intensity of 94%. No hematological grade 3-4 toxicities were observed. One patient had one episode of grade 3 mucositis and two patients (3.8%) suffered grade 2 asthenia. Eight patients (15.1%) experienced grade 2 neutropenia, grade 2 anemia was registered in seven patients (13.2%). No cardiotoxicity was observed. Ten out of 53 patients (18.9, 95% confidence interval 8.3, 29.4%) showed a complete response, whereas 28 (52.8, 95% confidence interval 39.4, 66.3%) had a partial response, with an overall response rate of 71.7% (95% confidence interval 59.6, 83.8%). In addition, 14 patients (26.4%) had stable disease. Median time to progression was 12 months (95% confidence interval 7, 17). Median response duration was 14 months (range 3-60). The 1-, 3- and 5-year survival rates were 90.1, 68.0 and 56.6%, respectively. In untreated metastatic breast cancer patients, the weekly administration of epirubicin and paclitaxel with granulocyte colony-stimulating factor support seems to be extremely tolerable and active, and deserves further investigation into a phase III trial.