A phase II study of neoadjuvant chemotherapy with docetaxel, cisplatin and trastuzumab for T2 breast cancers

Combination of Pertuzumab and Trastuzumab in the Treatment of HER2-Positive Early Breast Cancer: A Review of the Emerging Clinical Data

Human epidermal growth factor receptor type 2 (HER2) is a relevant and effective target in breast cancer. The development of monoclonal antibodies against HER2 has revolutionized the treatment of HER2-positive breast cancer. The humanized monoclonal antibody, trastuzumab, was the first in its class to be widely adopted. It was initially studied in the metastatic setting and then in the treatment of early-stage disease, demonstrating significant improvement in overall survival in both settings. The addition of pertuzumab further improved upon results achieved with trastuzumab and chemotherapy, specifically extending overall survival in patients with metastatic disease, lessening the risk of recurrence when used in the adjuvant setting, and improving pathologic complete response rate when utilized in the neoadjuvant setting. In this article, we review the studies that support the use of HER2-directed monoclonal antibodies in early-stage breast cancer both in the adjuvant and neoadjuvant settings and focus on the success of dual HER2-targeted therapy achieved with the combination of trastuzumab and pertuzumab. A newer way to administer these agents, specifically the subcutaneous formulation of pertuzumab and trastuzumab with recombinant human hyaluronidase, will also be discussed.

Neoadjuvant Chemotherapy with Docetaxel, Carboplatin and Weekly Trastuzumab Is Active in HER2-Positive Early Breast Cancer: Results after a Median Follow-Up of over 4 Years

INTRODUCTION

Most patients with HER2-positive breast cancer receive chemotherapy and trastuzumab. Data from adjuvant trials have shown that the combination of docetaxel, carboplatin and weekly trastuzumab (TCH) is well tolerated and as effective as anthracycline-containing regimes. Previous investigations on neoadjuvant treatment with taxanes, platinum salts and trastuzumab showed pathological complete remission (pCR) rates between 43.3 and 76%. To date, the longest published follow-up in this indication is 3 years. Here we present 4-year follow-up data for a cohort of 78 patients treated with neoadjuvant TCH.

METHODS

Between 2009 and 2014 we treated 78 patients with operable HER2-positive breast cancer with a neoadjuvant schedule of docetaxel (75 mg/m²) and carboplatin (AUC 6) every 3 weeks (q3w) and trastuzumab (4 mg/kg loading dose then 2 mg/kg) q1w. Lymph node involvement was verified by sentinel lymph node or core-cut biopsy. Patients were diagnosed at a mean age of 55.5 years; 65.4% had hormone receptor-positive tumors, 34.6% presented with grade 3 disease and 51.3% of patients were node positive. Patients were monitored every 2 cycles by ultrasound. After 6 cycles of chemotherapy all patients had surgery. Axillary dissection was performed in case of positive lymph node status prior to TCH. After surgery, trastuzumab was continued q3w up to 1 year.

RESULTS

No grade III/IV toxicities occurred and no case of congestive heart failure was observed. Neither dose modifications nor dose delays were necessary. 34 of the 78 patients (43.6%) achieved a pCR, 27 of the 40 node-positive patients (67.5%) experienced nodal conversion. After a median follow up of 48.5 months the disease-free survival (DFS) was 84.6%, the distant disease-free survival (DDFS) was 87.2% and the overall survival (OS) was 91%. Only T stage and nodal status at baseline were found to be significantly associated with survival estimates.

CONCLUSION

The anthracycline-free regimen TCH is effective and safe in the neoadjuvant therapy of HER2-positive breast cancer, yielding DFS, DDFS and OS probabilities comparable to the results of adjuvant trials. Our data support the use of TCH as a neoadjuvant therapy regimen for patients with HER2-positive breast cancer. They also strongly encourage the use of taxanes and platinum salts as the chemotherapy backbone in studies investigating dual blockade with trastuzumab and pertuzumab in the neoadjuvant setting.

An overview of the effective combination therapies for the treatment of breast cancer

Breast cancer (BC) is generally classified based on the receptors overexpressed on the cell nucleus, which include hormone receptors such as progesterone (PR) and estrogen (ER), and HER2. Triple-negative breast cancer (TNBC) is a type of cancer that lacks any of these three types of receptor proteins (ER/PR/HER2). Tumor cells exhibit drug resistant phenotypes that decrease the efficacy of chemotherapeutic treatments. Generally, drug resistance has a genetic basis that is caused by an abnormal gene expression, nevertheless, there are several types of drug resistance: efflux pumps reducing the cellular concentration of the drug, alterations in membrane lipids that reduce cellular uptake, increased or altered drug targets, metabolic alteration of the drug, inhibition of apoptosis, repair of the damaged DNA, and alteration of the cell cycle checkpoints. The use of "combination therapy" is recognized as an efficient solution to treat human diseases, in particular, breast cancer. In this review, we give examples of different nanocarriers used to co-deliver multiple therapeutics (chemotherapeutic agent and nucleic acid) to drug-resistant tumor cells, and lastly, we give our recommendations for the future directions for the co-delivery treatments.

Human breast cancer and lymph node metastases express Gb3 and can be targeted by STxB-vectorized chemotherapeutic compounds

BACKGROUND

The B-subunit of Shiga toxin (STxB) specifically binds to the glycosphingolipid Gb3 that is highly expressed on a number of human tumors and has been shown to target tumor cells in mouse models and ex vivo on primary colon carcinoma specimen.

METHODS

Using a novel ex vivo STxB labeling (ESL) method we studied Gb3 expression in cytological specimens of primary human breast tumors from 107 patients, and in synchronous lymph node metastases from 20 patients. Fluorescent STxB was incubated with fine-needle aspiration (FNA) specimens, and Gb3 expression was evaluated by fluorescence microscopy. Furthermore, 11 patient-derived human breast cancer xenografts (HBCx) were evaluated for expression of Gb3 by ESL and FACS. In addition, the biodistribution of fluorescent STxB conjugate was studied after intravenous injection in a Gb3 positive HBCx model.

RESULTS

Gb3 expression was detected in 62 of 107 patients (57.9%), mainly in epithelial tumor cells. Gb3 positivity correlated with estrogen receptor expression (p≤0.01), whereas absence of Gb3 expression in primary tumors was correlated with the presence of lymph node metastases (p≤0.03). 65% of lymph node metastases were Gb3 positive and in 40% of tested patients, we observed a statistically significant increase of metastatic Gb3 expression (p≤0.04). Using concordant ESL and flow cytometry analysis, 6 out of 11 HBCx samples were scored positive. Intravenous injections of fluorescent STxB into HBC xenografted mice showed preferential STxB accumulation in epithelial cells and cells with endothelial morphology of the tumor.

CONCLUSION

The enhanced expression of Gb3 in primary breast carcinomas and its lymph node metastases indicate that the development of STxB-based therapeutic strategies is of interest in this pathology. Gb3 expressing HBCx can be used as a model for preclinical studies with STxB conjugates. Finally, the ESL technique on FNA represents a rapid and cost effective method for the stratification of patients in future clinical trials.

RAD50 targeting impairs DNA damage response and sensitizes human breast cancer cells to cisplatin therapy

In tumor cells the effectiveness of anti-neoplastic agents that cause cell death by induction of DNA damage is influenced by DNA repair activity. RAD50 protein plays key roles in DNA double strand breaks repair (DSBs), which is crucial to safeguard genome integrity and sustain tumor suppression. However, its role as a potential therapeutic target has not been addressed in breast cancer. Our aim in the present study was to analyze the expression of RAD50 protein in breast tumors, and evaluate the effects of RAD50-targeted inhibition on the cytotoxicity exerted by cisplatin and anthracycline and taxane-based therapies in breast cancer cells. Immunohistochemistry assays on tissue microarrays indicate that the strong staining intensity of RAD50 was reduced in 14% of breast carcinomas in comparison with normal tissues. Remarkably, RAD50 silencing by RNA interference significantly enhanced the cytotoxicity of cisplatin. Combinations of cisplatin with doxorubicin and paclitaxel drugs induced synergistic effects in early cell death of RAD50-deficient MCF-7, SKBR3, and T47D breast cancer cells. Furthermore, we found an increase in the number of DSBs, and delayed phosphorylation of histone H2AX after cisplatin treatment in RAD50-silenced cells. These cellular events were associated to a dramatical increase in the frequency of chromosomal aberrations and a decrease of cell number in metaphase. In conclusion, our data showed that RAD50 abrogation impairs DNA damage response and sensitizes breast cancer cells to cisplatin-combined therapies. We propose that the development and use of inhibitors to manipulate RAD50 levels might represent a promising strategy to sensitize breast cancer cells to DNA damaging agents.

Cardiotoxicity of systemic agents used in breast cancer

Several breast cancer therapies can lead to cardiovascular toxicity: drugs such anthracyclines can cause permanent damage, anti-HER2 agents may cause transitory and reversible cardiac dysfunction and others, such as those used in endocrine therapy, primarily disturb lipid metabolism. Considering the seriousness of these complications, trials are now being conducted to address cardiotoxicity associated with new drugs; however, to fully understand their toxicity profiles, longer follow-up is needed. In this review, we compile the information available about cardiac toxicity related to well-established systemic breast cancer treatments, as well as newer drugs, including antiangiogenics, mTOR inhibitors and novel anti-HER2 agents. We also describe current and next generation cardiac biomarkers and functional tests that can optimize treatment and reduce and prevent the incidence of treatment-related cardiotoxicity.

Fluorouracil, epirubicin, and cyclophosphamide (FEC-75) followed by paclitaxel plus trastuzumab versus paclitaxel plus trastuzumab followed by FEC-75 plus trastuzumab as neoadjuvant treatment for patients with HER2-positive breast cancer (Z1041): a randomised, controlled, phase 3 trial

BACKGROUND

Neoadjuvant chemotherapy with trastuzumab for patients with HER2-positive breast cancer can produce a pathological complete response in the breast in 30-65% of patients. We investigated the effect of the timing of trastuzumab administration with anthracycline and taxane neoadjuvant chemotherapy.

METHODS

This randomised trial was done at 36 centres in the USA and Puerto Rico. Women with operable HER2-positive invasive breast cancer were randomly assigned (1:1) with a biased coin minimisation algorithm, stratified for age, tumour size, and hormone receptor status. Neither patients nor investigators (except for a cardiac safety review panel) were masked to treatment assignment. Patients randomly assigned to sequential treatment received fluorouracil 500 mg/m(2), epirubicin 75 mg/m(2), and cyclophosphamide 500 mg/m(2) (FEC-75) on day 1 of a 21-day cycle for four cycles followed by paclitaxel 80 mg/m(2) and trastuzumab 2 mg/kg (after a 4 mg/kg loading dose) once per week for 12 weeks, while those randomly assigned to the concurrent treatment group received paclitaxel and trastuzumab once per week for 12 weeks followed by four cycles of FEC-75 (on day 1 of each 21-day cycle) and once-weekly trastuzumab, in the same doses as the sequential group. Surgery, including evaluation of the axilla, was done within 6 weeks of completion of neoadjuvant treatment. The primary outcome was the percentage of patients who had a pathological complete response in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT00513292.

FINDINGS

From Sept 15, 2007, to Dec 15, 2011, 282 women were enrolled (140 in the sequential group, 142 in the concurrent group). Two patients in the sequential group withdrew consent before starting treatment. 78 of 138 (56·5%, 95% CI 47·8-64·9) patients who received sequential treatment had a pathological complete response in the breast versus 77 of 142 (54·2%, 95% CI 45·7-62·6) who received concurrent treatment (difference 2·3%, 95% CI -9·3 to 13·9). No treatment-related deaths occurred. The most common severe toxic effects were neutropenia (35 [25·3%] of 138 patients in the sequential group vs 45 [31·7%] of 142 patients in the concurrent group) and fatigue (six [4·3%] vs 12 [8·5%]). Left ventricular ejection fraction dropped below the institutional lower limit of normal at week 12 in one (0·8%) of 130 patients who received sequential treatment and four (2·9%) of 137 patients who received concurrent treatment; by week 24, it had dropped below this limit in nine (7·1%) of 126 patients and in six (4·6%) of 130 patients, respectively.

INTERPRETATION

Concurrent administration of trastuzumab with anthracyclines offers no additional benefit and is not warranted.

FUNDING

US National Cancer Institute.