Nonpegylated Liposomal Doxorubicin (TLC-D99), Paclitaxel, and Trastuzumab in HER-2-Overexpressing Breast Cancer: A Multicenter Phase I/II Study

Pediatric Cardio-Oncology Medicine: A New Approach in Cardiovascular Care

Survival for pediatric patients diagnosed with cancer has improved significantly. This achievement has been made possible due to new treatment modalities and the incorporation of a systematic multidisciplinary approach for supportive care. Understanding the distinctive cardiovascular characteristics of children undergoing cancer therapies has set the underpinnings to provide comprehensive care before, during, and after the management of cancer. Nonetheless, we acknowledge the challenge to understand the rapid expansion of oncology disciplines. The limited guidelines in pediatric cardio-oncology have motivated us to develop risk-stratification systems to institute surveillance and therapeutic support for this patient population. Here, we describe a collaborative approach to provide wide-ranging cardiovascular care to children and young adults with oncology diseases. Promoting collaboration in pediatric cardio-oncology medicine will ultimately provide excellent quality of care for future generations of patients.

Anthracyclines Strike Back: Rediscovering Non-Pegylated Liposomal Doxorubicin in Current Therapeutic Scenarios of Breast Cancer

Anthracyclines are among the most active chemotherapies (CT) in breast cancer (BC). However, cardiotoxicity is a risk and peculiar side effect that has been limiting their use in clinical practice, especially after the introduction of taxanes. Non-pegylated liposomal doxorubicin (NPLD) has been developed to optimize the toxicity profile induced by anthracyclines, while maintaining its unquestionable therapeutic index, thanks to its delivering characteristics that increase its diffusion in tumor tissues and reduce it in normal tissues. This feature allows NPLD to be safely administered beyond the standard doxorubicin maximum cumulative dose of 450-480 mg/m2. Following three pivotal first-line phase III trials in HER2-negative metastatic BC (MBC), this drug was finally approved in combination with cyclophosphamide in this specific setting. Given the increasing complexity of the therapeutic scenario of HER2-negative MBC, we have carefully revised the most updated literature on the topic and dissected the potential role of NPLD in the evolving therapeutic algorithms.

Trastuzumab Emtansine Plus Non-Pegylated Liposomal Doxorubicin in HER2-Positive Metastatic Breast Cancer (Thelma): A Single-Arm, Multicenter, Phase Ib Trial

Simple Summary

Considering the favorable overall safety profile of trastuzumab emtansine (T-DM1), the low expected rate of cardiotoxicity, and the synergistic effect of anthracyclines with Human Epidermal Growth Factor Receptor 2 (HER2)-targeting agents, it is hypothesized that T-DM1 may be safely combined with non-pegylated liposomal doxorubicin (NPLD). In the THELMA trial, the effect of adding NPLD to T-DM1 was evaluated with the aim of enhancing T-DM1 efficacy using an extensive cardiological assessment in trastuzumab- and taxane-pretreated patients with HER2-positive metastatic breast cancer. Despite an unlikely drug synergism, this combination was generally well tolerated without clinically relevant worsening of cardiac function. No relationship was identified between early predictors of heart failure and left ventricular ejection fraction changes. Thus, the combination of T-DM1 plus NPLD is safe, but this regimen does not seem to improve T-DM1 antitumor activity in this setting.

Abstract

The paper assesses the dose-limiting toxicities and the maximum tolerated dose (MTD) of trastuzumab emtansine (T-DM1) combined with non-pegylated liposomal doxorubicin (NPLD) in HER2-positive (HER2+) metastatic breast cancer (MBC). This single-arm, open-label, phase Ib trial (NCT02562378) enrolled anthracycline-naïve HER2+ MBC patients who had progressed on trastuzumab and taxanes. Patients received a maximum of 6 cycles of NPLD intravenously (IV) at various dose levels (45, 50, and 60 mg/m²) in the “3 plus 3” dose-escalation part. During expansion, they received 60 mg/m² of NPLD every 3 weeks (Q3W) plus standard doses of T-DM1. The MTD was T-DM1 3.6 mg/kg plus NPLD 60 mg/m² administered IV Q3W. No clinically relevant worsening of cardiac function was observed. Among all evaluable patients, the overall response rate was 40.0% (95%CI, 16.3–67.7) with a median duration of response of 6.9 months (95%CI, 4.8–9.1). Clinical benefit rate was 66.7% (95%CI, 38.4–88.2) and median progression-free survival was 7.2 months (95%CI, 4.5–9.6). No significant influence of NPLD on T-DM1 pharmacokinetics was observed. The addition of NPLD to T-DM1 is feasible but does not seem to improve the antitumor efficacy of T-DM1 in HER2+ MBC patients.

Antitumour Anthracyclines: Progress and Perspectives

Anthracyclines are ranked among the most effective chemotherapeutics against cancer. They are glycoside drugs comprising the amino sugar daunosamine linked to a hydroxy anthraquinone aglycone, and act by DNA intercalation, oxidative stress generation and topoisomerase II poisoning. Regardless of their therapeutic value, multidrug resistance and severe cardiotoxicity are important limitations of anthracycline treatment that have prompted the discovery of novel analogues. This review covers the most clinically relevant anthracyclines and their development over decades, since the first discovered natural prototypes to recent semisynthetic and synthetic derivatives. These include registered drugs, drug candidates undergoing clinical trials, and compounds under pre-clinical investigation. The impact of the structural modifications on antitumour activity, toxicity and resistance profile is addressed.

Anthracycline Cardiotoxicity: It Is Possible to Teach an Old Dog Some New Tricks

Anthracyclines have proved to be one of the most effective chemotherapeutic agents in the treatment of numerous solid tumors and hematologic malignancies in both adult and pediatric patients. Their clinical benefit, however, is sometimes hampered by the development of cardiotoxicity, a process that still remains elusive despite decades of investigation. It has been postulated that anthracycline-induced cardiotoxicity is mediated in part by reactive oxygen species and redox cycling. This article reviews anthracycline cardiotoxicity in terms of historical significance, epidemiology, current detection strategies, prevention strategies, and patient care after anthracycline-based chemotherapy.

Primary Prevention Strategies for Anthracycline Cardiotoxicity: A Brief Overview

The clinical use of doxorubicin and other antitumor anthracyclines is limited by a dose-related risk of cardiomyopathy and heart failure which may occur “on treatment” or any time, from months to years, after completing chemotherapy. Dose reductions diminish the incidence of cardiac events attributable to anthracyclines, but heart failure still occurs in some patients exposed to low or moderate anthracycline doses. Because anthracyclines improve the life expectancy of patients with, for example, breast cancer or lymphomas, preventing or diminishing the risk of early or delayed cardiotoxicity is of obvious clinical importance. Here, we briefly review some potential strategies of primary prevention that are based on what we know about the molecular mechanisms of cardiotoxicity, and what can be done, or might be done, to interfere with the pharmacokinetic, pharmacodynamic, and genetic determinants of cardiotoxicity.

Distinct biodistribution of doxorubicin and the altered dispositions mediated by different liposomal formulations

The liposomal formulations of doxorubicin produced distinct efficacy and toxicity profiles compared to doxorubicin solution in cancer patients. This study aims to investigate the drug tissue distribution and the driving force for tissue distribution from doxorubicin solution and two liposomal delivery systems, Doxil and Myocet. These three formulations were intravenously administered to mice at a single dose of 5mg/kg. Eleven organs, plasma and blood were collected at different time points. Total doxorubicin concentrations in each specimen were measured with LC-MS/MS. Compared to doxorubicin solution, both Doxil and Myocet produced distinct doxorubicin tissue exposure in all 11 tissues. Interestingly, the tissue exposure by Myocet was drastically different from that of Doxil and showed a formulation-dependent pattern. Cmax of doxorubicin in heart tissue by Doxil and Myocet was approximately 60% and 50% respectively of that by doxorubicin solution. The predominant driving force for doxorubicin tissue distribution is liposomal-doxorubicin deposition for Doxil and free drug concentration for doxorubicin solution. For Myocet, the driving force for tissue distribution is predominately liposomal-doxorubicin deposition into tissues within the first 4h; as the non-PEGylated doxorubicin liposomal decomposes, the driving force for tissue distribution is gradually switched to the released free doxorubicin. Unique tissue distributions are correlated with their toxicity profiles.

Trastuzumab cardiotoxicity: from clinical trials to experimental studies

Epidermal growth factor receptor-2 (HER-2) is overexpressed in 20 to 25% of human breast cancers, which is associated with aggressive tumour growth and poor prognosis. Trastuzumab (Herceptin®) is a humanized monoclonal antibody directed against HER-2, the first highly selective form of therapy targeting HER-2 overexpressing tumours. Although initial trials indicated high efficacy and a favourable safety profile of the drug, the first large, randomized trial prompted a retrospective analysis of cardiac dysfunction in earlier trials utilizing trastuzumab. There has been ongoing debate on the cardiac safety of trastuzumab ever since, initiating numerous clinical and preclinical investigations to better understand the background of trastuzumab cardiotoxicity and evaluate its effects on patient morbidity. Here, we have given a comprehensive overview of our current knowledge on the cardiotoxicity of trastuzumab, primarily focusing on data from clinical trials and highlighting the main molecular mechanisms proposed.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Emerging delivery systems to reduce doxorubicin cardiotoxicity and improve therapeutic index: focus on liposomes

Anthracyclines are powerful anticancer agents and among the most important tools in the chemotherapy armamentarium of medical oncologists. They are approved for use in the treatment of a broad variety of solid and hematologic neoplasms. However, the usefulness of these agents, particularly doxorubicin, the most widely used anthracycline, is limited by considerable toxicity, especially damage to the cardiac muscle, which is cumulative and mostly irreversible, restricting extended use of this drug. In the last 30 years, extensive research with a variety of drug-delivery systems has attempted to overcome this limitation, with clinical success mostly confined to liposome formulations. Liposomal doxorubicin, and particularly pegylated liposomal doxorubicin, has shown significant pharmacologic advantages and an added clinical value over doxorubicin. Here, we review the mechanisms of action and toxicity of doxorubicin, and ways to reduce toxicity, with a focus on liposome-based drug-delivery systems.

HER2-positive metastatic breast cancer: a changing scenario

Adjuvant trastuzumab (AT) dramatically improved HER2-positive breast cancer prognosis. Relapsed disease after AT has different patterns and information is available from observational studies. In this Review Chemotherapy regimens combined to anti-HER2 blockade are discussed, focusing in particular the role of anthracyclines, taxanes and capecitabine. The use of trastuzumab beyond progression and the role of other anti-HER2 agents like lapatinib, pertuzumab and T-DM1 are explored, as also dual blockade and in trastuzumab resistant Patients. Metastatic "de novo" HER2 Luminal (co-expression of HER2 and hormone receptors) Patients are eligible for anastrozole and trastuzumab but if pretreated with trastuzumab they are also eligible for lapatinib and letrozole. In any case endocrine treatment plays a complementary role to chemotherapy which remains pivotal. The last topic explored is treatment options for patients with brain metastases where both trastuzumab given concurrent with radiotherapy or lapatinib and capecitabine appear as potentially active.

The concomitant management of cancer therapy and cardiac therapy

Antitumor drugs have long been known to introduce a measurable risk of cardiovascular events. Cardio-Oncology is the discipline that builds on collaboration between cardiologists and oncologists and aims at screening, preventing or minimizing such a risk. Overt concern about "possible" cardiovascular toxicity might expose cancer patients to the risk of tumor undertreatment and poor oncologic outcome. Careful analysis of risk:benefit balance is therefore central to the management of patients exposed to potentially cardiotoxic drugs. Concomitant or sequential management of cardiac and cancer therapies should also be tailored to the following strengths and weaknesses: i) molecular mechanisms and clinical correlates of cardiotoxicity have been characterized to some extent for anthracyclines but not for other chemotherapeutics or new generation "targeted" drugs, ii) anthracyclines and targeted drugs cause different mechanisms of cardiotoxicity (type I versus type II), and this classification should guide strategies of primary or secondary prevention, iii) with anthracyclines and nonanthracycline chemotherapeutics, cardiovascular events may occur on treatment as well as years or decades after completing chemotherapy, iv) some patients may be predisposed to a higher risk of cardiac events but there is a lack of prospective studies that characterized optimal genetic tests and pharmacologic measures to minimize excess risk, v) clinical toxicity may be preceded by asymptomatic systolic and/or diastolic dysfunction that necessitates innovative mechanism-based pharmacologic treatment, and vi) patient-tailored pharmacologic correction of comorbidities is important for both primary and secondary prevention. Active collaboration of physicians with laboratory scientists is much needed for improving management of cardiovascular sequelae of antitumor therapy. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

Efficacy and safety of neoadjuvant chemotherapy with concurrent liposomal-encapsulated doxorubicin, paclitaxel and trastuzumab for human epidermal growth factor receptor 2-positive breast cancer in clinical practice

BACKGROUND

Based on previous results obtained with non-pegylated liposomal-encapsulated doxorubicin (TLC-D99) together with paclitaxel and trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive locally advanced or metastatic breast cancer (BC), a similar regimen was evaluated in the neoadjuvant setting in a prospectively selected series of consecutive patients with clinical stage II-III BC. Primary and secondary objectives included the rate of pathologic complete response (pCR), safety, and predictive factors of pCR.

METHODS

Patients received six cycles of TLC-D99 (50 mg/m(2) every 3 weeks), paclitaxel (80 mg/m(2) weekly) and trastuzumab (4 mg/kg initial dose and 2 mg/kg weekly). All patients underwent surgery after treatment. pCR was defined as the absence of invasive cancer cells in the breast and the axilla.

RESULTS

Sixty-two patients with a median age of 46.6 years were analyzed. Stage IIIA was diagnosed in 43.5% of patients and 14.5% had inflammatory BC. Conservative surgery was performed in 46.8% of the patients and pCR was achieved in 63% (95% CI 50.5-75.5). Patients with estrogen receptor (ER)-negative tumors presented a significantly higher pCR rate than patients with ER-positive tumors (74.4 vs 43.5%; P = 0.028). Forty-five patients (72.6%) completed study treatment and 80.6% received at least five treatment cycles. No patients developed congestive heart failure and 14.5% of patients showed a ≥ 10 % decrease in the left ventricular ejection fraction.

CONCLUSION

The triple combination therapy assessed is effective and safe, offering a high pCR rate in patients with HER2-positive BC.

Biweekly combination of trastuzumab, docetaxel and gemcitabine for HER2-positive metastatic breast cancer: results of a Phase II GOIM study

ABSTRACT: 

Aims: Clinical activity of chemotherapy plus trastuzumab in HER2 overexpressing advanced breast cancer has been documented. We report the activity and safety results of biweekly combination of trastuzumab, docetaxel and gemcitabine as first-line therapy in HER2-positive advanced breast cancer. Patients & methods: Patients were biweekly treated with trastuzumab (4 mg/kg), gemcitabine (1000 mg/m2) and docetaxel (50 mg/m2). The primary end point was overall response rate, secondary time to progression, clinical benefit rate (partial response plus complete response plus stable disease for ≥ 24 weeks) and tolerability. Results: A total of 65 patients with HER2-positive advanced breast cancer have been enrolled. In total, 47 patients responded (73%; 95% CI, 60–84), 11 achieved complete response (17%; 95% CI: 8.9–28.7), 36 achieved partial response (56%; 95% CI: 43–68.6). The clinical benefit rate was 87.5% (95% CI: 77–94). Three patients (4.7%) experienced progressive disease. The median time to progression was 14.2 months (95% CI: 10.6–17.8), the median overall survival was 39.3 months and the 36-month survival rate was 55.5% (95% CI: 58–73). The worst toxicities were grade 3 neutropenia (12%), thrombocytopenia (6%) and diarrhea (6%). No cardiac toxicity was reported. Conclusion: As first-line therapy, this combination allowed the delivery of polychemotherapy in association to targeted therapy, with clinical activity and mild toxicity. The promising results should be further explored in Phase III randomized clinical trials.

Phase III trial of nonpegylated liposomal doxorubicin in combination with trastuzumab and paclitaxel in HER2-positive metastatic breast cancer

BACKGROUND

Nonpegylated liposomal doxorubicin liposomal doxorubicin, (Myocet™; Sopherion Therapeutics, Inc Canada, and Cephalon, Europe) (NPLD; Myocet(®)) in combination with trastuzumabHerceptin(®) (Hoffmann-La Roche) has shown promising activity and cardiac safety. We conducted a randomized phase III trial of first-line NPLD plus trastuzumab and paclitaxel (Pharmachemie B.V.) (MTP) versus trastuzumab plus paclitaxel (TP) in patients with human epidermal growth factor 2 receptor (HER2)-positive metastatic breast cancer.

PATIENTS AND METHODS

Patients were randomly assigned to NPLD (M, 50 mg/m(2) every 3 weeks for six cycles), trastuzumab (T, 4 mg/kg loading dose followed by 2 mg/kg weekly), and paclitaxel (P, 80 mg/m(2) weekly) or T + P at the same doses until progression or toxicity. The primary efficacy outcome was progression-free survival (PFS).

RESULTS

One hundred and eighty-one patients were allocated to receive MTP, and 183 to TP. Median PFS was 16.1 and 14.5 months with MTP and TP, respectively [hazard ratio (HR) 0.84; two-sided P = 0.174]. In patients with estrogen receptor (ER)- and progesterone receptor (PR)-negative tumors, PFS was 20.7 and 14.0 months, respectively [HR 0.68; 95% confidence interval (CI) 0.47-0.99]. Median overall survival (OS) was 33.6 and 28.9 months with MTP and TP, respectively (HR 0.79; two-sided P = 0.083). In ER- and PR-negative tumors, OS was 38.2 and 27.9 months, respectively (HR 0.63; 95% CI 0.42-0.93). The frequency of adverse events was higher with MTP, but there was no significant difference in cardiac toxicity between treatment arms.

CONCLUSION(S)

The trial failed to demonstrate a significant clinical improvement with the addition of M to TP regimen. The clinical benefit observed in an exploratory analysis in the ER- and PR-negative population deserves consideration for further clinical trials.

CLINICAL TRIAL NUMBER

NCT00294996.

Substituting Doxorubicin with nonpegylated liposomal Doxorubicin for the treatment of early breast cancer: results of a retrospective study

Introduction. Evidence from the metastatic setting suggests that replacing conventional doxorubicin with nonpegylated liposomal doxorubicin (NPLD) for early breast cancer may maintain efficacy whilst reducing long-term cardiotoxicity, an important consideration with many patients going on to receive multiple lines of treatment. Methods. Consecutive patients with early breast cancer treated with NPLD were assessed for disease progression and changes in cardiac function according to left ventricular ejection fraction (LVEF). Results. Ninety-seven patients (median age at diagnosis 51 (32–76) years) were studied. The majority received NPLD (60 mg/m² plus cyclophosphamide 600 mg/m²) adjuvantly (79.4%) and in sequence with a taxane (79.4%; docetaxel 75 mg/m²). 80.4% had radiotherapy and 15.5% received trastuzumab. Mean time to disease recurrence was 87.0 months (80.7–93.2 [95% confidence interval]) and 5-year disease-free survival was 86.0%. Mean LVEF values remained within the normal range of ≥55% during treatment and throughout the cardiac follow-up period (median 7 months, range 1–21 months). Use of trastuzumab and age at diagnosis did not appear to influence LVEF. Conclusion. NPLD appeared to be a well-tolerated substitute for conventional doxorubicin in patients with early breast cancer.

HCVAD plus imatinib or dasatinib in lymphoid blastic phase chronic myeloid leukemia

BACKGROUND

Chronic myeloid leukemia (CML) may progress to blast phase (BP) at the rate of 1% to 1.5% per year. With the use of single-agent tyrosine kinase inhibitors, median overall survival ranges between 7 and 11 months.

METHODS

The outcome was analyzed for 42 patients with lymphoid BP-CML who were treated with hyperfractionated cyclophosphamide, vincristine, Adriamycin, dexamethasone (HCVAD) plus imatinib or dasatinib.

RESULTS

Complete hematological response was achieved in 90% of patients, complete cytogenetic remission in 58%, and complete molecular remission in 25%. Flow cytometry minimal residual disease negativity was achieved by 42% of evaluable patients after induction. Eighteen patients received allogeneic stem cell transplant (SCT) while in first complete hematological response. Median remission duration was 14 months and was longer among SCT recipients (P = .01) on multivariate analysis. Median overall survival was 17 months (range, 7-27 months) and was longer among SCT recipients (P < .001) and patients treated with dasatinib (P = .07) on multivariate analysis. Although a high rate of hematologic toxicity (100%) and infectious complications (59%) were observed, the related rate of treatment discontinuation was low (7% and 9%, respectively).

CONCLUSIONS

HCVAD combined with tyrosine kinase inhibitors is an effective regimen for the management of BP-CML, particularly when followed by allogeneic SCT.

Liposomal Doxorubicin in the treatment of breast cancer patients: a review

Drug delivery systems can provide enhanced efficacy and/or reduced toxicity for anticancer agents. Liposome drug delivery systems are able to modify the pharmacokinetics and biodistribution of cytostatic agents, increasing the concentration of the drug released to neoplastic tissue and reducing the exposure of normal tissue. Anthracyclines are a key drug in the treatment of both metastatic and early breast cancer, but one of their major limitations is cardiotoxicity. One of the strategies designed to minimize this side effect is liposome encapsulation. Liposomal anthracyclines have achieved highly efficient drug encapsulation and they have proven to be effective and with reduced cardiotoxicity, as a single agent or in combination with other drugs for the treatment of either anthracyclines-treated or naïve metastatic breast cancer patients. Of particular interest is the use of the combination of liposomal anthracyclines and trastuzumab in patients with HER2-overexpressing breast cancer. In this paper, we discuss the different studies on liposomal doxorubicin in metastatic and early breast cancer therapy.

Advances in first-line treatment for patients with HER-2+ metastatic breast cancer

BACKGROUND

The prognosis for breast cancer patients overexpressing human epidermal growth factor receptor (HER)-2 has changed with anti-HER-2-targeted therapy. Although anti-HER-2 therapy with trastuzumab and chemotherapy is the standard first-line treatment, the best therapeutic regimen has yet to be defined, and new strategies are evolving.

METHODS

A literature review of well-established and recently published trials, reviews, and ongoing clinical trials addressing first-line treatment for HER-2(+) metastatic breast cancer patients was performed.

RESULTS

Taxanes are the agents most commonly used in combination with trastuzumab, but other chemotherapy drugs, such as anthracyclines, vinorelbine, and gemcitabine and triple-combination therapies including platinum compounds, capecitabine, and taxanes have been studied. The combination of aromatase inhibitors with anti-HER-2 therapies is a new therapeutic option for some patients who coexpress HER-2 and hormone receptors, although its activity observed in randomized clinical trials seems to be inferior to that of chemotherapy plus anti-HER-2 therapies. In addition, new anti-HER-2 therapies have shown activity in HER-2(+) tumors, both alone and in combination with trastuzumab.

CONCLUSIONS

Trastuzumab plus chemotherapy is the current standard of care for the upfront treatment of HER-2(+) breast cancer patients, though other anti-HER-2-targeting agents may appear as new standards in the upcoming years.

Heart to heart with trastuzumab: a review on cardiac toxicity

Trastuzumab is regarded as the foundation of care for HER2-positive breast cancer as it has revolutionized the treatment of this disease across all settings. Although generally well tolerated, patients may develop symptomatic or asymptomatic cardiotoxicity, forcing a discontinuation of treatment, therefore preventing patients from benefiting from maximal disease control. Evolving research supports that trastuzumab-induced cardiotoxicity may be prevented or at least minimized by a number of prophylactic measures, such as identification of patients at risk and close monitoring. Optimized chemotherapy regimens, scheduling and formulations also contribute to minimizing cardiac adverse events. Equally important, if cardiotoxicity develops, medical interventions are now available that facilitate the reintroduction of trastuzumab once normal cardiac function has been restored. Awareness of this still-evolving information may lead to optimal use of trastuzumab, especially in combination regimens, maximizing antitumor benefit, while minimizing risk.

Emerging drugs in metastatic breast cancer: an update

INTRODUCTION

The incidence of breast cancer at an advanced stage has decreased in the modern world due to screening programs and usage of novel chemotherapy agents at an adjuvant setting. Recurrence is the major problem seen in > 50% of breast cancer patients diagnosed at an early stage. Developing new drugs for metastatic breast cancer is a huge and challenging research area.

AREAS COVERED

Emerging drugs showed positive results in clinical studies and agents in routine clinical usage are updated. Current treatment strategies as a combination of biologic agents and overcoming drug resistance are discussed. Literature search is made from PubMed, ASCO and San Antonio Breast Cancer Symposium Meeting abstracts.

EXPERT OPINION

A number of drugs caused survival benefit for advanced breast cancer. Hundreds of new studies with tens of agents are conducted for treatment of metastatic breast cancer. Tumor resistance and treatment related toxicities are unavoidable which are two main search areas for improving metastatic breast cancer management. Understanding the pathways of genesis and progression yielded many targets for treatment. However, cure in metastatic breast cancer is still a far aim and new agents and treatment strategies are needed.

"Short Course" of Nonpegylated Liposomal Doxorubicin Plus Paclitaxel and Trastuzumb as Primary Systemic Therapy for Operable and Locally-Advanced Breast Cancer: A Phase II Study (PacLiDox 07)

Background

Schedules with anthracyclines and taxanes are one of the best options for primary chemotherapy. The addition of trastuzumab showed an impressive percentage of pathological complete responses in Buzdar trial (66.7%). Recently, nonpegylated liposome-encapsulated doxorubicin (NLD) has been widely used in advanced breast cancer with high response rates (98.1 % in Cortes study). The aims of our study were to assess pathological responses and toxicity of NLD plus paclitaxel (and trastuzumab in patients with HER2 overexpression).

Methods

Thirty patients entered the study: 9 locally advanced and 21 operable. Median age was 58.5 years (range: 31-73). 23 patients without HER2 overexpression (or FISH not amplified) were treated with NLD 50 mg/m² every three weeks for 3 courses and weekly paclitaxel 80 mg/m² for 8 courses. 7 patients with HER2 overexpression or FISH amplified were treated with the same schedules plus trastuzumab (Herceptin) 4 mg/kg for the first administration and 2 mg/kg for the following 7 weekly administrations.

Results

Pathological complete response (pCR) was documented in 1 patient (treated with trastuzumab); no residual tumor (infiltrating or “in situ”) on breast was documented in other 2 patients. Objective clinical responses were documented in 22 patients (73.3%): 8 complete, 10 partial and 4 “minimal” responses. 7 patients have shown stable and 1 progressive disease. Clinical response in patients with HER2 overexpression treated with trastuzumab was 100% (4 complete and 3 partial responses). Conservative surgery was performed in 8 (38%) and mastectomy in 13 (62%) out of 21 operable patients; however, 7 out of 14 responding patients with operable disease underwent quadrantectomy (50%). Main toxicity was neutropenia: febrile in 2 patients (7%) and gr. 3-4 in 13 (43%). Other grade 3 toxicities were as follows: vomiting in 1 patient, asthenia in 1 patient, joint symptom in 1 patient. 3 patients were withdrawn from the study. No episodes of left ventricular ejection fraction (LVEF) < 50% were recorded (with a median reduction of 8%).

Conclusions

A “short course” of paclitaxel and NLD is active in terms of clinical response and conservative surgery for patients with potentially operable and locally advanced breast cancer; toxicity was manageable. High activity of the combination with trastuzumab has been confirmed. However, with this “short course” schedule, the result in term of clinical responses didn't turn into complete pathological responses.

A phase I/II trial of non-pegylated liposomal doxorubicin, docetaxel and trastuzumab as first-line treatment in HER-2-positive locally advanced or metastatic breast cancer

AIM

To assess the activity and safety of non-pegylated liposomal doxorubicin (Myocet®) in combination with docetaxel and trastuzumab as first-line treatment of patients with HER-2/neu-positive metastatic breast cancer (MBC).

PATIENTS AND METHODS

The maximum tolerated dose of the combination was defined in the phase I part of the study. In the phase II part, 45 HER-2/neu-positive MBC patients were enrolled to receive 6-8 cycles of Myocet® 50 mg/m2 (day 1), docetaxel 30 mg/m2 (days 2 and 9) plus trastuzumab (day 2, 4 mg/kg followed by 2 mg/kg/week) every 21 d until unacceptable toxicity or progression occurred. Objective response (primary end-point) and treatment tolerability were assessed according to World Health Organisation criteria. Cardiotoxicity was defined as signs and/or symptoms of congestive heart failure and/or a decrease in left ventricular ejection fraction (LVEF).

RESULTS

The overall response rate was 55.6% (complete response 8.9%, partial response 46.7%), with a median time-to-progression of 10.9 months (C.I. 8.7-15.0). Median overall survival was not reached. The most frequent grade 3-4 adverse events were granulocytopaenia (60.0%), leukocytopenia (43.2%) and alopecia (35.6%). Grade 3-4 diarrhoea, pain, oral and skin toxicity (4.4%, each) and nausea/vomiting, thrombocytopenia and elevated alkaline phosphatase (2.2%, each) were also reported. In 2 patients LVEF fell to <50%, with a decrease from baseline>15%. LVEF median values remained stable from baseline to the end of the study (60%).

CONCLUSIONS

The combination of Myocet®, docetaxel and trastuzumab is safe and shows promising activity as first-line treatment of HER-2-positive MBC.

Anthracycline cardiotoxicity

INTRODUCTION

Anthracyclines are widely prescribed anticancer agents that cause a dose-related cardiotoxicity, often aggravated by nonanthracycline chemotherapeutics or new generation targeted drugs. Anthracycline cardiotoxicity may occur anytime in the life of cancer survivors. Understanding the molecular mechanisms and clinical correlates of cardiotoxicity is necessary to improve the therapeutic index of anthracyclines or to identify active, but less cardiotoxic analogs.

AREAS COVERED

The authors review the pharmacokinetic, pharmacodynamic and biochemical mechanisms of anthracycline cardiotoxicity and correlate them to clinical phenotypes of cardiac dysfunction. Attention is paid to bioactivation mechanisms that converted anthracyclines to reactive oxygen species (ROS) or long-lived secondary alcohol metabolites. Preclinical aspects and clinical implications of the "oxidative stress" or "secondary alcohol metabolite" hypotheses are discussed on the basis of literature that cuts across bench and evidence-based medicine. Interactions of anthracyclines with comorbidities or unfavorable lifestyle choices were identified as important cofactors of the lifetime risk of cardiotoxicity and as possible targets of preventative strategies.

EXPERT OPINION

Anthracycline cardiotoxicity is a multifactorial process that needs to be incorporated in a translational framework, where individual genetic background, comorbidities, lifestyles and other drugs play an equally important role. Fears for cardiotoxicity should not discourage from using anthracyclines in many oncologic settings. Cardioprotective strategies are available and should be used more pragmatically in routine clinical practice.

[Non-pegylated doxorubicin (Myocet®) as the less cardiotoxic alternative of free doxorubicin]

Anthracyclines have probably been considered to be the most active agents for the treatment of breast cancer and some other solid tumors and hematological malignancies. However, they are associated with dose-related cardiotoxicity, which can lead to progressive myocardial damage and limits the maximal cumulative dose that can be given. This review focuses on the non-pegylated liposome-encapsulated doxorubicin (Myocet®), which has been developed to increase the therapeutic index of free doxorubicin. The encapsulation of doxorubicin within a macromolecular vector, such as a liposome ("nanoparticle based drug delivery system") reduces its distribution volume, diminishing its toxicity for healthy tissues while increasing the concentration within the neoplastic tissue. The most common adverse event is neutropenia, which is consistent with previous experience with free doxorubicin. Available evidence suggests that the incidence of hematological toxicity is lower than with conventional doxorubicin. Myocet® both as a single agent and in combination is effective and safe with an associated reduction in incidence and severity of cardiac events. Nagykálnai T. Non-pegylated doxorubicin (Myocet®) as the less cardiotoxic alternative of free doxorubicin.

Role of trastuzumab in the management of HER2-positive metastatic breast cancer

Breast cancer is a major health issue in developed countries. Overexpression of HER2, a member of epidermal growth factor receptor family, occurs in 20%-30% of breast cancers. HER2 drives the cancer cells to develop a more aggressive phenotype, to metastasize to viscera and central nervous system, and to be less sensitive to chemotherapeutic agents. Trastuzumab (Herceptin®) is a monoclonal antibody directed against the extracellular domain of HER2. As single agent or with chemotherapy, trastuzumab improves survival of HER2-positive breast cancers. In the past years, trastuzumab has completely revolutionized the scenario of the treatment of HER2-positive breast cancer, representing one of the most remarkable examples of targeted therapy in oncology. However, issues such as the best chemotherapeutic companion to associate with trastuzumab, cardiac toxicities, and clinical resistance still require tremendous efforts by researchers. Here, we review pharmacology, efficacy studies, and toxicities of trastuzumab in metastatic breast cancer. Moreover, we provide some insights on resistance to therapy. Finally, we briefly discuss trastuzumab's place in the clinical setting.

Novel cytotoxic backbones and targeted therapies: recent data and ongoing clinical trials

Novel therapies are emerging for treatment of patients with localized or advanced breast cancer. Targeted therapies such as trastuzumab, lapatinib, and bevacizumab have demonstrated significant clinical benefit in the metastatic setting, and trastuzumab has also improved patient outcome as adjuvant therapy in HER2+ breast cancer. Novel chemotherapies are also being developed to improve drug delivery, enhance efficacy, or decrease drug toxicity. These novel cytotoxic agents are being combined with established targeted therapies and are showing early promise for the treatment of patients with advanced breast cancer. Finally, new targeted therapies have shown clinical benefit, either as single agents or in combination with established targeted therapy or chemotherapy.

Underuse of anthracyclines in women with HER-2+ advanced breast cancer

This article examines how discouraging the use of anthracyclines in combination with trastuzumab in patients with human epidermal growth factor receptor 2 positive metastatic breast cancer because of fears of cardiotoxicity has influenced the use of these agents in this patient setting.

Anthracyclines are among the most active drugs in breast cancer. Because of excessive cardiotoxicity, their use in combination with trastuzumab has been discouraged in patients with human epidermal growth factor receptor (HER)-2⁺ metastatic breast cancer. We sought to describe how this treatment paradigm influenced the use of anthracyclines in this patient setting.

We analyzed a multi-institutional database containing the treatment history of 450 patients who received at least one trastuzumab-based regimen for HER-2⁺ metastatic breast cancer. Patients were considered eligible for anthracyclines for metastatic disease if they were never exposed (NE) or had been previously exposed (PE) to an anthracycline in the neoadjuvant or adjuvant setting and had relapsed after 12 months from the last dose. We then assessed the use of anthracycline-based therapy after failure with the first trastuzumab-based regimen in eligible patients.

Three-hundred twenty-one patients were considered eligible for anthracyclines. In total, 190 eligible patients developing disease progression during the initial trastuzumab-based therapy were analyzed. An anthracycline was administered as first salvage treatment in 14 NE and two PE patients. Another 15 NE and nine PE patients received an anthracycline as a further line of therapy. Of 119 eligible patients who died from breast cancer, only 30 received an anthracycline for metastatic disease.

In conclusion, despite the fact that two thirds of the patients receiving trastuzumab-based therapy for HER-2 metastatic breast cancer are eligible for anthracyclines, these drugs are infrequently used nowadays to treat trastuzumab-refractory disease. A role for these compounds should be redefined in this patient subset.

Phase II trial of pegylated liposomal doxorubicin plus docetaxel with and without trastuzumab in metastatic breast cancer: Eastern Cooperative Oncology Group trial E3198

The purpose of this trial was to determine cardiac toxicity and overall efficacy of the pegylated liposome doxorubicin (PLD)-docetaxel couplet alone if HER2-negative metastatic breast cancer (internal control) or with trastuzumab if HER2-positive disease. Upon central HER2 confirmation, 84 eligible patients received induction with PLD (30 mg/m(2)) and docetaxel (60 mg/m(2)) every 3 weeks (maximum eight cycles), alone if HER2-negative (arm A; N = 38) or plus trastuzumab (4 mg/kg once, then 2 mg/kg weekly) if HER2-positive disease (arm B; N = 46) as first-line therapy. Maintenance therapy (without PLD) allowed. Primary objectives were to determine whether congestive heart failure (CHF) rate >3% and the efficacy/toxicity of each arm. CHF rate was <3% in each arm. Response rate, median progression-free-, and overall survival in arms A and B were 47.4 and 45.7%, 11 and 10.6 months, and 24.6 and 31.8 months, respectively. Trastuzumab arm was associated with higher rates of hand foot syndrome (grade 3: 22 vs. 38%; P = 0.16; overall 51 vs. 75%, P = 0.03) and treatment discontinuation due to toxicity/patient withdrawal (13 vs. 28%; P = 0.11). Febrile neutropenia occurred in approximately 10% of patients. In conclusion, concurrent administration of trastuzumab with PLD-docetaxel was not associated with higher risk of cardiac toxicity compared with PLD-docetaxel alone, but led to excessive hand-foot syndrome.

A multicentre Phase II study of non-pegylated liposomal doxorubicin in combination with trastuzumab and docetaxel as first-line therapy in metastatic breast cancer

To evaluate the cardiotoxicity, general toxicity, and activity of non-pegylated liposomal doxorubicin, in combination with docetaxel and trastuzumab, as first-line therapy in metastatic breast cancer. Thirty-one patients with metastatic human epidermal growth factor receptor 2-overexpressing breast cancer, who had not previously received chemotherapy for metastatic disease, received non-pegylated liposomal doxorubicin (50 mg/m(2)), docetaxel (75 mg/m(2)) and trastuzumab (2 mg/kg/week) for up to eight cycles, followed by trastuzumab alone for up to 52 weeks. Cardiotoxicity was defined as a decrease in left ventricular ejection fraction (LVEF) to below 45%, or a decrease in LVEF of at least 20% from baseline. Mean LVEF was maintained at baseline level also in the subset of patients who had received anthracycline previously. Cardiotoxicity developed in three patients during the treatment cycles, and in two further patients after the end of the study. The most common adverse events were haematological toxicity, alopecia, asthenia and fever. The best overall response rate was 65.5%. Median time to progression was 13.0 months. The combination of non-pegylated liposomal doxorubicin, docetaxel and trastuzumab combines acceptable cardiac and general toxicity and promising activity as first-line therapy in metastatic breast cancer.

Management of HER2-positive breast cancer in Asia: consensus statement from the Asian Oncology Summit 2009

Patients with breast cancer positive for human epidermal growth-factor receptor type 2 (HER2) are an important subgroup for consideration in the Asian context. Rationally designed, anti-HER2 targeted agents that can substantially improve treatment outcomes have become commercially available, but are still too costly for some groups in developed countries and for underdeveloped and developing nations. This review discusses the available evidence for optimum management of HER2-positive early and advanced breast cancer, and how this evidence can be applied to Asian countries with different levels of health-care resources and economic development--using framework provided by the Breast Health Global Initiative. We provide a brief overview of HER2 testing and discuss management of early and advanced HER2-positive breast cancer, and formulate a consensus statement for the management of breast cancer in the context of basic, limited, enhanced, and maximum health-care resource availability.

Improving the therapeutic index of anthracycline chemotherapy: focus on liposomal doxorubicin (Myocet)

Anthracyclines are valuable cytotoxic agents in cancer treatment. However, their usefulness is limited by cumulative dose-dependent cardiotoxicity that may manifest as life-threatening congestive heart failure. To avoid cardiotoxicity, the use of doxorubicin is typically capped at a safe cumulative dose. Liposomal formulations may reduce cardiac risks whilst maintaining anti-cancer efficacy. Efficacy and safety studies of non-pegylated liposomal doxorubicin (NPLD) in metastatic breast cancer (MBC) are reviewed, along with studies that examine efficacy and cardiac tolerability in combination with newer agents such as paclitaxel and trastuzumab. These show that cardiac safety of liposomal doxorubicin is similar to that of epirubicin in cumulative dose, but that the formulation, unlike epirubicin, has similar anti-cancer efficacy to doxorubicin at equimolar doses. Liposomal doxorubicin may have a better therapeutic index than non-liposomal anthracyclines. This justifies further studies in patients where cumulative cardiotoxicity is a concern, as does study of its use with other potentially cardiotoxic agents.

Simultaneous analysis of liposomal doxorubicin and doxorubicin using capillary electrophoresis and laser induced fluorescence

A method based on a capillary electrophoresis with laser induced fluorescence detection was developed and validated for simultaneous separation of doxorubicin (DOX) and liposomal encapsulated DOX. The separation was accomplished using a fused silica capillary (60cm in total length, 75microm I.D.) and potassium phosphate buffer [12.5mM, pH 7.4] as the running buffer. The effect of sample preparation conditions on maintaining liposomal integrity was also investigated. The limit of detection for DOX was 0.1microg/ml and the precision and accuracy of CE/LIF method was within the ranges of FDA guidelines. The validated method was successfully used to quantify DOX in human plasma using a direct injection of a 4-fold dilution of spiked liposomal DOX in human plasma.