Results of a phase II study of liposomal doxorubicin (Myocet®) in combination with weekly paclitaxel and trastuzumab (Herceptin®) In patients with HER2-positive locally advanced or metastatic breast cancer (LA/MBC)

Enhanced delivery of Paclitaxel using electrostatically-conjugated Herceptin-bearing PEI/PLGA nanoparticles against HER-positive breast cancer cells

We have developed a novel nanoparticle delivery system fabricated from polyethylenimine (PEI) and poly(d,l-lactide-co-glycolide) (PLGA), which were able to deliver the chemotherapeutic agent Paclitaxel, while the biomacromolecule Herceptin acted as a targeting ligand that was conjugated onto the surfaces of the nanoparticles via electrostatic interactions. In this study, these electrostatically-conjugated Herceptin-bearing PEI/PLGA nanoparticles (eHER-PPNs) were optimized and employed as vectors to target HER2-positive breast cancer cells. The eHER-PPNs had an average diameter of ∼ 280 nm and a neutral surface charge (1.00 ± 0.73 mV), which remained stable under physiological conditions. The anticancer effects of eHER-PPNs were investigated in HER2-positive BT474 cells and HER2-negative MCF7 cells. The eHER-PPNs showed enhanced cytotoxicity that was dependent on the receptor expression levels and the incubation time. These conjugated nanoparticles deliver Paclitaxel more efficiently (p<0.001) than unmodified PPNs, Herceptin and the combined effects of these two monotherapies. Furthermore, the chemically-conjugated Herceptin-bearing PEI/PLGA nanoparticles (cHER-PPNs) were fabricated as a comparison. The eHER-PPNs exhibited lower cell viability (46.7%) than that of cHER-PPNs (65.1%). The targeting ability of eHER-PPNs was demonstrated through confocal microscopy images and flow cytometry, which showed that eHER-PPNs displayed higher cellular uptake efficiency (p<0.001) in comparison with cHER-PPNs. Therefore, eHER-PPNs could provide promising platforms for the delivery of therapeutic drugs against HER2-positive breast cancers.

SEOM clinical guidelines for the treatment of metastatic breast cancer

Patients with metastatic breast cancer have a wide number of treatment options, including medical, surgical, and supportive care measures. Treatment decisions are based in predictive and prognostic factors and the informed choice of the patients. SEOM has elaborated these guidelines with evidence-based recommendations for the diagnostic work-up, treatment (chemotherapy, endocrine therapy and targeted therapies) and supportive care for the management of these patients.

Anthracycline cardiotoxicity in breast cancer patients: synergism with trastuzumab and taxanes

Doxorubicin is known to cause cardiomyopathy and congestive heart failure (CHF) upon chronic administration. A major obstacle to doxorubicin-containing multiagent therapies pertains to the possible development of cardiomyopathy and CHF at lower than expected cumulative doses of doxorubicin. For example, the cardiac toxicity of doxorubicin is aggravated by the anti-HER2 antibody Trastuzumab or by the tubulin-active taxane paclitaxel; however, the mechanisms by which Trastuzumab and paclitaxel aggravate doxorubicin-induced cardiotoxicity are mechanistically distinct: Trastuzumab interferes with cardiac-specific survival factors that help the heart to withstand stressor agents like anthracyclines, while paclitaxel acts by stimulating the formation of anthracycline metabolites that play a key role in the mechanism of cardiac failure. Here, we briefly review the molecular mechanisms of the cardiotoxic synergism of Trastuzumab or paclitaxel with doxorubicin, and we attempt to briefly outline how the mechanistic know-how translates into the clinical strategies for improving the safety of anthracycline-based multiagent therapies.

Safety and activity of trastuzumab-containing therapies for the treatment of metastatic breast cancer: our long-term clinical experience (GOIM study)

BACKGROUND

Trastuzumab is widely used as the treatment of choice for HER2-positive metastatic breast cancer (MBC).

PATIENTS AND METHODS

Seventy patients, median age 57 years and range 31-81 years, were included in our retrospective analysis with the aim to evaluate safety and activity of trastuzumab-containing therapies.

RESULTS

We observed for first-line treatment response rate (RR) 41%, stable disease (SD) 47% and time to progression (TTP) 8 months (range 1-44). Corresponding numbers for second line were RR 23%, SD 62% and (TTP) 9 months (range 3-23) and beyond second line RR 22%, SD 78% and (TTP) 9 months (range 4-19). Overall survival was 19.2 months (3-62 months). The median cumulative dose of trastuzumab administrated was 5286 mg (464-17 940 mg). Trastuzumab was well tolerated. Median left ventricular ejection function (LVEF) at baseline was 62% and at the end of treatment was 59%. The more relevant adverse events consisted of an asymptomatic decrease in LVEF to 40% (baseline 60%) and a grade 3 symptomatic increase in bilirubin.

CONCLUSION

Trastuzumab-containing therapies in MBC show a good safety and toxicity profile and a remarkable activity even in heavily pretreated women. Patients should benefit from continued trastuzumab therapy, as shown by the maintenance of (TTP) even beyond second-line treatment.

HER‐2‐Positive Metastatic Breast Cancer: Optimizing Trastuzumab‐Based Therapy

Trastuzumab with a taxane as first-line therapy is now the standard of care for patients with human epidermal growth factor receptor 2 (HER-2)-positive metastatic breast cancer (MBC). The search for additional and more effective trastuzumab-based therapies continues. Novel combinations of trastuzumab with chemotherapeutic agents, including vinorelbine, gemcitabine, and capecitabine, and hormonal therapy agents, such as tamoxifen and aromatase inhibitors, are currently under investigation in clinical trials. Available data suggest these combinations will provide additional treatment options that may ultimately lead to better outcomes for patients with HER-2-positive MBC. Evidence is growing for the use of trastuzumab treatment beyond disease progression and retreatment after (neo)adjuvant relapse is being explored to assist in clinical decision making. Already, the use of trastuzumab in the metastatic setting has changed HER-2-positive status from a marker of poor prognosis to one of better overall outcome, and ongoing studies should expand further the treatment options for patients with HER-2-positive MBC.

Randomized Phase II Trial of weekly paclitaxel alone versus trastuzumab plus weekly paclitaxel as first-line therapy of patients with Her-2 positive advanced breast cancer

BACKGROUND

A randomized Phase II study evaluated the activity of weekly paclitaxel versus its combination with trastuzumab for treatment of patients with advanced breast cancer overexpressing HER-2.

PATIENTS AND METHODS

Among 124 patients randomized, 123 are assessable for toxicity and 118 for response. Patients received weekly paclitaxel single agent (80 mg/m2) or combined with trastuzumab (4 mg/kg loading dose, then weekly 2 mg/kg). HER-2 overexpression was determined by immunohistochemistry (IHC). Patients with 2+/3+ IHC scores were eligible. IHC was compared with HER-2 serum extracellular domain (ECD).

RESULTS

Patient characteristics were similar in the two arms. Both treatments were feasible and well tolerated with no grade 4 hematologic toxicity. No patient developed cardiac toxicity. The combined treatment was statistically significant superior for overall response rate (ORR) (75% vs. 56.9%; P = 0.037), particularly in the subset of IHC 3+ patients (84.5% vs. 47.5%; P = 0.00050). A statistically significant better median time to progression was seen in the subgroup with IHC 3+ (369 vs. 272 days; P = 0.030) and visceral disease (301 vs. 183 days; P = 0.0080) treated with combination. Multivariable analysis of predictive factors showed that only IHC score retained statistically significant value for ORR (P = 0.0035).

CONCLUSION

Weekly paclitaxel plus trastuzumab is highly active and safe and it is superior to paclitaxel alone in patients with IHC score of 3+.

Randomized phase II trial of the efficacy and safety of trastuzumab combined with docetaxel in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer administered as first-line treatment: the M77001 study group

PURPOSE

This randomized, multicenter trial compared first-line trastuzumab plus docetaxel versus docetaxel alone in patients with human epidermal growth factor receptor 2 (HER2) -positive metastatic breast cancer (MBC).

PATIENTS AND METHODS

Patients were randomly assigned to six cycles of docetaxel 100 mg/m2 every 3 weeks, with or without trastuzumab 4 mg/kg loading dose followed by 2 mg/kg weekly until disease progression.

RESULTS

A total of 186 patients received at least one dose of the study drug. Trastuzumab plus docetaxel was significantly superior to docetaxel alone in terms of overall response rate (61% v 34%; P = .0002), overall survival (median, 31.2 v 22.7 months; P = .0325), time to disease progression (median, 11.7 v 6.1 months; P = .0001), time to treatment failure (median, 9.8 v 5.3 months; P = .0001), and duration of response (median, 11.7 v 5.7 months; P = .009). There was little difference in the number and severity of adverse events between the arms. Grade 3 to 4 neutropenia was seen more commonly with the combination (32%) than with docetaxel alone (22%), and there was a slightly higher incidence of febrile neutropenia in the combination arm (23% v 17%). One patient in the combination arm experienced symptomatic heart failure (1%). Another patient experienced symptomatic heart failure 5 months after discontinuation of trastuzumab because of disease progression, while being treated with an investigational anthracycline for 4 months.

CONCLUSION

Trastuzumab combined with docetaxel is superior to docetaxel alone as first-line treatment of patients with HER2-positive MBC in terms of overall survival, response rate, response duration, time to progression, and time to treatment failure, with little additional toxicity.

The future of breast cancer: the role of prognostic factors

There remains a number of unmet clinical needs in patients with breast cancer that research and development aims to address. More sensitive and specific indicators of prognosis are required to identify those patients at greatest risk for disease progression. A number of biological markers including the cyclins, circulating epithelial cells, and components of the urokinase plasminogen system have been shown to correlate with patient outcome. Genomic analysis also has the potential to predict patient response to specific agents, thus ensuring patients derive the maximum benefit from the treatment they receive. Patients who require treatment are often exposed to the undesirable toxic effects that are associated with some treatments. Liposomal and nanoparticle formulations of currently available agents have been shown to be at least as effective as their parent compounds but with improved safety and tolerability profiles. Studies into patient quality of life during therapy have highlighted the importance of early administration of an erythropoietic agent to treat chemotherapy-induced anemia. Further research in breast cancer should further optimize the treatment patients receive ensuring that patients not only live longer but also have quality survival.

Optimizing the treatment of metastatic breast cancer

There is currently no standard care for metastatic breast cancer; consequently, individual patient and tumor characteristics are among several factors considered in treatment decisions. Clinical studies continue to clarify the roles of endocrine therapy, chemotherapy, and biologic therapy, and results have been promising. For patients with hormone receptor-positive disease, several endocrine agents are currently available including selective estrogen receptor (ER) modulators (tamoxifen and toremifene), aromatase inhibitors (anastrozole, exemestane, and letrozole), as well as the selective ER down-regulator, fulvestrant. Effective first- and second-line, single-agent chemotherapeutic treatments include the taxanes, anthracyclines, vinorelbine, capecitabine, and gemcitabine. The benefits of sequential, single-agent versus combination chemotherapy are also being evaluated. Although combination chemotherapy generally results in a greater objective response, it is associated with similar survival and usually greater toxicity compared with sequential, single-agent chemotherapy. Research involving biologic therapy continues to provide encouraging results for patients with metastatic breast cancer. Chemotherapy plus trastuzumab has been shown to result in greater overall survival versus chemotherapy alone in human epidermal growth factor 2 (HER-2)-positive patients. Trastuzumab has been associated with cardiotoxicity when administered with conventional anthracyclines. Newer formulations of anthracyclines have been developed (e.g., liposomal anthracyclines) to decrease the incidence of cardiotoxicity, and these provide additional treatment options for patients with metastatic breast cancer. The potential effect of all of these endocrine, chemotherapeutic, and biologic treatments on quality of life is an important consideration. Additionally, integrating patient concerns into treatment decisions and collaborating with cross-disciplinary healthcare providers can help to manage the disease more effectively.

Optimizing treatment of HER2-positive metastatic breast cancer

The primary goal of therapy for metastatic breast cancer is to improve the outcome for patients. Ideally, this should be achieved with minimal short-term side effects and without long-term irreversible toxicity. Trastuzumab (Herceptin; F. Hoffmann-La Roche, Basel, Switzerland) is proven to be efficacious in women with metastatic breast cancer who have HER2-positive disease. Data from pivotal clinical trials and postmarketing surveillance in women with metastatic breast cancer confirm that trastuzumab is also well tolerated with a low incidence of conventional chemotherapeutic side effects. Severe adverse events are confined to serious infusion-related reactions and cardiac issues, which are infrequent and readily managed. Patients at risk of these severe events can be identified before starting trastuzumab therapy. Ideally, treatment should also be convenient for the patient. This can be achieved through less frequent dosing. A 3-weekly trastuzumab schedule, with higher individual loading and maintenance doses than the conventional weekly schedule, has been investigated. This has similar efficacy, tolerability, and pharmacokinetics (exposure) to the weekly regimen, providing a convenient schedule.

Maximizing clinical benefit with trastuzumab

To optimize patient management in breast cancer a number of factors are considered, including hormone receptor and HER2 status. A feasible approach for women with less aggressive, estrogen receptor/HER2-positive metastatic breast cancer is to consider trastuzumab (Herceptin; F. Hoffmann-La Roche, Basel, Switzerland) combined with endocrine therapy. Randomized clinical trials are ongoing to assess the combination of trastuzumab with aromatase inhibitors. In patients with aggressive HER2-positive metastatic breast cancer, trastuzumab/chemotherapy combination regimens are warranted. When administered first line in combination with a taxane, trastuzumab improves all clinical outcome parameters, including survival, in such patients. Trastuzumab adds little to the toxicity profile of taxanes, and trastuzumab combination therapy is associated with improvements in quality of life when compared with chemotherapy alone. There is encouraging evidence of improved efficacy when trastuzumab is combined with other cytotoxic agents with proven single-agent activity in breast cancer, including capecitabine (Xeloda; F. Hoffmann-La Roche), gemcitabine, and vinorelbine. Trastuzumab is also being investigated as part of triplet drug regimens. Trastuzumab has good single-agent activity in first-line therapy. This is of relevance to women with HER2-positive disease who are not suitable for, or do not wish to receive, cytotoxic chemotherapy. The benefits noted with trastuzumab-containing regimens were documented in clinical trials where trastuzumab was given until disease progression. A further rationale exists to continue trastuzumab beyond progression. Data from retrospective reviews indicate that this strategy is feasible.