Circulating HER2 extracellular domain and resistance to chemotherapy in advanced breast cancer.

To test the hypothesis of an association between HER2 and chemotherapy resistance, we performed a prospective assessment of the predictive value of the circulating HER2 extracellular domain (ECD) in patients with advanced breast carcinoma in the setting of a multicenter Phase II trial using paclitaxel and doxorubicin. Serum samples were collected from 58 patients with metastatic breast carcinoma before first-line chemotherapy for advanced disease, and the levels of circulating HER2 ECD were measured using an enzyme immunoassay. Immunohistochemistry with anti-HER2 monoclonal antibody CB11 was used to assess the overexpression of HER2 in the primary tumors. When 450 fmol/ml was used as a cutoff, 24 cases (41%) had elevated HER2 ECD levels. Elevated levels of circulating HER2 ECD were associated with the expression of HER2 in the primary tumor tissue and with the metastatic tumor burden (evaluated with the marker CA 15-3; P = 0.032 and P = 0.002, respectively) but not with variables such as menopausal status, stage at diagnosis, previous adjuvant therapy, or the number of metastatic sites. The levels of circulating HER2 ECD correlated inversely with the response to treatment. The probability of obtaining a complete response to chemotherapy was significantly lower (P = 0.021) in patients with elevated HER2 ECD levels (0%; 95% confidence interval, 0-13%) compared with patients with nonelevated HER2 (26%; 95% confidence interval, 12-45%). In addition, the duration of clinical response was significantly shorter in patients with elevated HER2 ECD, compared with the cases with nonelevated HER2 (7.5 versus 11 months; P = 0.035). In conclusion, elevated levels of circulating HER2 ECD in patients with metastatic breast cancer correlate with reduced efficacy of a paclitaxel-doxorubicin chemotherapy combination. We suggest that the poor response rate associated with HER2 expression in advanced breast cancer may not be reversed by aggressive chemotherapy alone.     

A Phase II Neoadjuvant Trial of Sequential Nanoparticle Albumin-Bound Paclitaxel Followed by 5-Fluorouracil/Epirubicin/Cyclophosphamide in Locally Advanced Breast Cancer

BackgroundNeoadjuvant chemotherapy has become standard treatment for women with locally advanced breast cancer (LABC). Various regimens have explored the addition of newer agents to determine safety and efficacy. The aim of this phase II study was to incorporate albumin-bound paclitaxel with sequential anthracycline-based therapy.Patients and MethodsSixty-six women with LABC but without prior treatment and regardless of hormone receptor or HER2 status were enrolled. All patients were to receive albumin-bound paclitaxel weekly for 12 weeks followed by 5-fluorouracil/epirubicin/cyclophosphamide (FEC) every 3 weeks for 4 cycles. Trastuzumab was allowed in HER2-positive (HER2⁺) patients. Primary endpoint was pathologic complete response (pCR; CR) in breast. Secondary endpoints included pCR in breast and nodes, clinical CR, 2-year progression-free survival, and overall survival.ResultsSixty-five patients received at least 1 dose of chemotherapy and were included in this analysis. Sixty-three patients completed 4 cycles of albumin-bound paclitaxel. Sixty-two patients received at least 1 dose of FEC, and 58 completed 4 cycles. Seventeen of 19 HER2⁺ women received trastuzumab. The pCR in breast was 29% (19 of 65). For the HER2⁺ subset, the pCR was 58% (11 of 19). Both albumin-bound paclitaxel and FEC were well tolerated. The most significant toxicities were grade 2/3 neuropathy (16%) with albumin-bound paclitaxel and grade 3/4 febrile neutropenia (7%) with FEC.ConclusionAlbumin-bound paclitaxel given over 12 weeks is well tolerated. Albumin-bound paclitaxel should be further evaluated in a randomized setting in both adjuvant and neoadjuvant trials.     

Serum HER2 extracellular domain in metastatic breast cancer patients treated with weekly trastuzumab and paclitaxel: association with HER2 status by immunohistochemistry and fluorescence in situ hybridization and with response rate.

PURPOSE: We explored the relationship between circulating HER2 extracellular domain (ECD) and tissue HER2 status as determined by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). We also examined its predictive value in a cohort of metastatic breast cancer patients treated with weekly trastuzumab and paclitaxel. METHODS: Eligible patients had pre- and post-treatment stored serum specimens and were treated on a previously reported phase II trial. Retrospective analysis evaluated: the association between pretreatment serum HER2 ECD and tissue HER2 status by IHC and FISH; and the association between change in serum HER2 ECD after 12 weeks of therapy and response proportion. RESULTS: Stored serum samples were available for 55/95 (58%) patients. Statistically significant associations were found between HER2 status as assessed by IHC and FISH, and baseline serum HER2 ECD level. Patients whose ECD normalized after 12 weeks of therapy had a higher response proportion compared with patients with persistently high ECD levels (68% versus 15%, P=0.005). A relative decline of over 55% from baseline HER2 ECD predicted response to therapy. CONCLUSION: A statistically significant association was observed between pretreatment serum HER2 ECD and tissue HER2 status as assessed by IHC and FISH. A decrease in serum HER2 ECD level was a significant predictor of response to trastuzumab-based therapy.     

Monitoring the circulating levels of the HER2/neu oncoprotein in breast cancer

The HER2/neu oncoprotein is a major target for the development of new cancer therapies and is similar to the estrogen receptor, which guides hormone therapy. The HER2/neu status is used to guide therapy decisions in patients with HER2/neu-overexpressing breast cancer tumors. The HER2/neu oncogene, or c-erbB-2, encodes a transmembrane receptor protein that is expressed on normal epithelial cells and can be overexpressed in breast cancer cells. Studies have shown that the extracellular domain (ECD) of the HER2/neu oncoprotein is released from the cell and can be measured in the circulation of women with breast cancer. Enzyme-linked immunosorbent assay methods used to measure the circulating HER2/neu ECD have shown that the prevalence of elevated ECD levels is approximately 18.1% in women with primary breast cancer and approximately 45.6% in women with metastatic breast cancer (MBC). Many studies have monitored the circulating ECD levels after surgery and indicate that increasing ECD levels can indicate recurrence of breast cancer earlier than clinical diagnosis. Studies in women with MBC showed that serial changes in circulating HER2/neu ECD levels paralleled the clinical course of disease, regardless of the treatment regimen. Several studies identified a subgroup of patients with MBC who had HER2/neu-negative disease by tissue testing but developed elevated ECD levels with MBC. In contrast to tissue testing, which is a one-time event, monitoring the circulating levels of the HER2/neu ECD in patients with breast cancer provides a real-time assessment of the HER2/neu status and provides important information for managing the therapy of patients with MBC.     

贝伐单抗联合白蛋白结合型紫杉醇治疗难治三阴性乳腺癌的初步临床观察

为了评价贝伐单抗联合白蛋白结合型紫杉醇治疗晚期难治性三阴性乳腺癌的临床效果,选取经病理学确诊的晚期三阴性乳腺癌患者6例(ER、PR和HER-2均为阴性),既往使用过蒽环、紫杉类、吉西他滨及卡培他滨等药物治疗后进展,接受贝伐单抗联合白蛋白结合型紫杉醇方案治疗,其中贝伐单抗7.5 mg/kg,静脉滴入,d1,3周重复;白蛋白结合型紫杉醇260 mg/m2,静脉滴入,d1,3周重复,不做抗过敏预处理.3例患者接受化疗6个周期,3例4个周期.PR 2例,SD 3例,PD 1倒.毒副反应主要是骨髓抑制和神经毒性,其中Ⅳ度粒细胞减少1例,Ⅲ度粒细胞减少2倒,Ⅱ度粒细胞减少2倒,Ⅰ度粒细胞减少1例;Ⅲ度感觉神经病变2例,Ⅱ度感觉神经病变2例,Ⅰ度感觉神经病变2例;高血压1倒,蛋白尿2例.初步研究结果提示,贝伐单抗联合白蛋白结合型紫杉醇治疗晚期难治性三阴性乳腺癌疗效较好,毒副反应可耐受,值得进一步研究.     

The efficacy of bevacizumab plus paclitaxel as first-line treatment for HER2-negative metastatic breast cancer: a meta-analysis of randomized controlled trials

Although both bevacizumab and paclitaxel significantly improve the efficacy of chemotherapy for human epidermal growth factor receptor 2 (HER2)-negative patients with metastatic breast cancer (MBC), little have changed with overall survival rates when they have been used alone or combined with other chemotherapy. Thus, a meta-analysis was conducted to evaluate the efficacy of bevacizumab combined with paclitaxel in HER2-negative MBC patients. Pubmed and Embase were systematically reviewed for studies published up to September 2013 in which bevacizumab plus paclitaxel were compared with other chemotherapy. Primary outcomes comprised overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Eight phase II/III clinical trials met the inclusion criteria, with a total of 3,758 patients. The pooled results showed that combination of bevacizumab and paclitaxel significantly improved the PFS (HR?=?0.63, 95 % CI, 0.55–0.73, P?=?0.011), ORR (RR?=?1.28, 95 % CI, 0.96–1.70, P?=?0.0), but had no effect on OS (HR?=?0.91, 95 % CI, 0.81–1.01, P?=?0.855). The meta-analysis confirms the benefits of bevacizumab–paclitaxel combination therapy in HER2 negative metastatic breast cancer, with an improvement in both progression free survival and objective response rate. However, no significant OS benefit was observed.     

Changes over time of extracellular domain of HER2 (ECD/HER2) serum levels have prognostic value in metastatic breast cancer

Background Blood levels of the extracellular domain of HER-2/neu (ECD/HER2) have been suggested to have potential as a tumor marker in breast cancer. Our aim was to assess the prognostic value of baseline levels of ECD/HER2, but more importantly changes in levels over time, in women with metastatic breast cancer. Methods Baseline and serial levels of ECD/HER2 were measured in 158 women with newly-diagnosed metastatic breast cancer, in whom we previously performed serial measurement of plasma osteopontin. ECD/HER2 was measured in 1,282 serum samples using a validated ELISA at baseline and every 3–12 weeks during and after therapy until death (median, n = 8 samples per patient). Multivariate time-dependent survival analyses were conducted using models that right-censored patient outcomes 3, 6 and 12 months after last known ECD/HER2 measurement. Results Thirty-four patients (22%) had elevated baseline ECD/HER2 (median 10.2 ng/ml: range 4.1–40.4 ng/ml). In univariate analysis, elevated baseline ECD/HER2 was associated with short survival (P = 0.001). In a multivariate model incorporating standard clinical prognostic factors, baseline ECD/HER2 was significantly associated with survival duration (RR 1.029; P = 0.020). Presence of visceral metastases and ECOG status 2–4 also retained significance. In a multivariate model incorporating standard prognostic factors and changes in sequential ECD/HER2 levels, an ECD/HER2 increase of >12 ng/ml at any time was the variable with most prognostic value for poor survival (RR 6.10; P = 0.0003); poor ECOG status also retained significance. Conclusion Increases over time of ECD/HER2 levels were strongly associated with poor survival in this cohort of women with metastatic breast cancer. An invited commentary to this article can be found at doi:.     

Biweekly paclitaxel plus gemcitabine in advanced breast cancer: phase II trial and predictive value of HER2 extracellular domain.

BACKGROUND: We wanted to assess the toxicity and efficacy of paclitaxel plus gemcitabine in advanced breast cancer and to confirm whether circulating HER2 extracellular domain (ECD) correlates with treatment response. PATIENTS AND METHODS: Forty-three patients received paclitaxel 150 mg/m2 followed by gemcitabine 2500 mg/m2, both on day 1 of 14-day cycles, with a maximum of eight cycles. Serum levels of HER2 ECD were assessed by ELISA. RESULTS: All patients were evaluable for toxicity and 42 for efficacy. Overall toxicity was low. Grade 3 neutropenia occurred in 12% of patients and grade 4 in 17%, and other grade 3 toxicities in <5%. One patient had an allergic infusion reaction. Overall response rate was 71% [95% confidence interval (CI) 62% to 81%], with 11 patients achieving a complete response (26%). With a median follow-up of 26 months, the median time to progression was 16.6 months. Response rate correlated significantly with HER2 ECD, with 42% of HER2 ECD-positive patients responding versus 83% of HER2 ECD-negative patients (P = 0.02). Furthermore, response duration was shorter in patients with positive HER2 ECD levels (7.9 versus 14.4 months; P = 0.04). CONCLUSIONS: Paclitaxel plus gemcitabine given as an every 2-weeks schedule is a well tolerated and active regimen in advanced breast carcinoma. This is an attractive combination to use when anthracyclines are not indicated, such as in HER2 positive cases that receive trastuzumab. In addition, elevated levels of HER2 ECD adversely affect the efficacy of treatment.     

HER2/HER3 heterodimers and p21 expression are capable of predicting adjuvant trastuzumab response in HER2+ breast cancer

Human epidermal growth factor receptor 2 (HER2) plays an important role in breast cancer progression and provides predictive information for response to targeted therapy including trastuzumab although this is limited. Downstream pathways, such as PI3K/Akt, are associated with HER2/HER3 heterodimerization promoting survival and proliferation amongst cancer cells. Thus, patient outcome and trastuzumab therapy effectiveness might be further characterised by HER2/HER3 dimerisation and its signalling pathways. HER2/HER3 dimerisation status was assessed, using chromogenic in situ Proximity Ligation Assay, in two breast cancer series: early stage primary breast cancer, including 224 HER2+ patients that were not submitted to trastuzumab, and HER2+ breast cancer where patients were treated with adjuvant trastuzumab (n = 143). Levels of biomarkers including PI3K, pAKT, ER, PgR, HER3, BCL2, p53, PTEN and p21 were measured using immunohistochemistry. Levels of HER2/HER3 heterodimers were compared with biomarker expression and patient outcome. An association between high levels of HER2/HER3 dimerisation and absence of hormone receptors, ER and PgR, was observed. We further show for the first time the presence of HER2/HER3 heterodimers and the loss of p21 expression in HER2+ breast cancer predicts a significantly poorer outcome when submitted to adjuvant trastuzumab. Breast cancer patients that reveal high levels of HER2/HER3 dimerisation and loss of p21 are associated with poor survival prognosis in patients with HER2+ breast cancer treated with adjuvant trastuzumab. Further quantification analysis of HER dimer/ligand complexes and downstream signalling pathways will begin to unravel the complex associations with patient outcome and its relationship with sensitivity to targeted treatment.     

Phase I–II study of the farnesyl transferase inhibitor tipifarnib plus sequential weekly paclitaxel and doxorubicin–cyclophosphamide in HER2/neu-negative inflammatory carcinoma and non-inflammatory estrogen receptor-positive breast carcinoma

Tipifarnib (T) is a farnesyl transferase inhibitor (FTI) that enhances the antineoplastic effects of cytotoxic therapy in vitro, has activity in metastatic breast cancer, and enhances the pathologic complete response (pCR) rate to neoadjuvant doxorubicin–cyclophosphamide (AC) chemotherapy. We, therefore, performed a phase I–II trial of T plus neoadjuvant sequential weekly paclitaxel and 2-week AC chemotherapy in locally advanced breast cancer. Eligible patients with HER2-negative clinical stage IIB–IIIC breast cancer received 12 weekly doses of paclitaxel (80 mg/m²) followed by AC (60/600 mg/m² every 2 weeks and filgrastim), plus T (100 or 200 mg PO on days 1–3 of each P dose, and 200 mg PO on days 2–7 of each AC cycle). The trial was powered to detect an improvement in breast pCR rate from 15 to 35 % (α = 0.10, β = 0.10) in two strata, including ER and/or PR-positive, non-inflammatory (stratum A) and inflammatory carcinoma (stratum B). Of the 60 patients accrued, there were no dose-limiting toxicities among the first six patients treated at the first T dose level (100 mg BID; N = 3) or second T dose level (200 mg BID; N = 3) plus paclitaxel. Breast pCR occurred in 6/33 patients (18 %, 95 % confidence intervals (CI) 7–36 %) and 1/22 patients (4 %, 95 % CI 0–8 %) in stratum B. Combination of the FTI T with weekly paclitaxel–AC is unlikely to be associated with a breast pCR rate of 35 % or higher in patients with locally advanced HER2/neu-negative inflammatory or non-inflammatory ER- and/or PR-positive breast carcinoma.     

Trastuzumab plus paclitaxel or docetaxel in HER-2-negative/HER-2 ECD-positive anthracycline- and taxane-refractory advanced breast cancer

Trastuzumab is considered effective against human epidermal growth factor receptor (HER)-2-positive breast cancer as assessed by immunohistochemistry (IHC) and fluorescence or chromogenic in situ hybridization (FISH/CISH) on biopsy material. Trastuzumab is now approved in both the adjuvant and metastatic settings for this patient population. Because HER-2 extracellular domain (ECD) levels have been correlated with disease progression in the metastatic setting, we considered trastuzumab salvage therapy plus a taxane in heavily pretreated trastuzumab-naive relapsed breast cancer patients with high serum levels of HER-2 ECD (> or =15 ng/ml). All patients had previously failed at least two lines of anthracycline- and taxane-based regimens and were HER-2 negative by IHC and FISH/CISH prior to a centralized reanalysis, and were serum positive for HER-2 ECD (> or =15 ng/ml) at baseline. Regular serum accounts of HER-2 ECD were recorded and compared with response and survival outcomes. Twenty-two patients were finally eligible for salvage therapy. Minor responses were observed in five (23%) and stable disease (SD) was observed in 11 patients, leading to a clinical benefit rate of 73% (16 of 22 patients). The median time to progression and overall survival time were 5 (6.5 months in minor responders and SD) and 12 months, respectively; 11 and eight patients remained progression free for >6 and >12 months, respectively. Eleven and seven patients were alive at 12 and 15 months, respectively, after treatment start. Furthermore, in total, 13 (59.1%) patients obtained a biochemical response. In our study, patients with conventionally HER-2-negative disease but with expression of HER-2 ECD above the normal limit (> or =15 ng/ml) displayed a rapid response, both biochemically and clinically, to the trastuzumab-taxane combination. This is the first study assessing anti-HER-2-based treatment in HER-2-negative advanced breast cancer according to HER-2 ECD positivity; if our results are confirmed, additional patients with "hidden" HER-2-positive breast cancer might benefit from anti-HER-2 treatment.     

Role of cytotoxics in combination with targeted agents

Combining cytotoxics with targeted agents can lead to enhanced efficacy in metastatic breast cancer (MBC). Cytotoxic/targeted agent combinations approved for the treatment of MBC include trastuzumab plus paclitaxel or docetaxel for the first-line treatment in patients presenting with HER2-positive breast cancer. Furthermore, in HER2-negative disease combining bevacizumab with paclitaxel for the first-line treatment of HER2-negative patients is superior compared to monotherapy with either drug. Lapatinib plus capecitabine recently received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) for conditional marketing authorisation in patients with HER2-positive breast cancer following prior therapy with anthracyclines, taxanes and trastuzumab. The novel epothilone ixabepilone is also under investigation in this setting. Preclinical studies have demonstrated synergistic activity in combination with targeted agents including trastuzumab and bevacizumab and early clinical studies have revealed encouraging response rates in combination with trastuzumab and carboplatin in patients with HER2-positive MBC. This article will review recent data on the efficacy of combining cytotoxics with targeted agents for the treatment of MBC.     

Importance of confirming HER2 overexpression of recurrence lesion in breast cancer patients

Background

The systemic management of metastatic breast cancer (MBC) is usually based on ER or HER2 status of the primary tumor. However, the hormonal status or the overexpression of human epidermal growth factor 2 (HER2) may change in every metastatic site because of the effects of the long-term treatment of metastatic cancer with endocrine therapy, chemotherapy, or biological agents. The purpose of this study was to investigate the frequency of change in HER2 expression in primary and distant metastatic tumors in breast cancer patients. Another objective of the study was to examine the effect of the clinical therapy on the basis of HER2 expression in a metastatic tumor.

Materials and methods

In our hospital between 1991 to December 2010, retrospectively, 156 patients had biopsy or surgical resection of their metastatic site. All sample were analyzed pathologically to confirm metastatic disease and, second, to evaluate HER2 status by immunohistochemistry or by FISH.

Results

The recurrence lesions were resected from the breast or lymph node (n = 67, local lesion), brain (n = 27), lung (n = 16), liver (n = 20), bone (n = 16), and from the stomach, intestine, ovary, and uterus (n = 10). Loss, increase, or no change in HER2 overexpression was observed in 3, 5, and 92%, respectively. Positive changes of HER2 in metastatic sites were 3 (4%) local lesion, 3 (11%) brain, 1 (7%) lung, 0 (0%) liver, 2 (17%) bone, and 0 (0%) others. In 3 of these 8 patients, trastuzumab was administered. In 2 of 3 patients, trastuzumab achieved long stable disease. The negative conversion rate of HER2 expression in metastatic lesions was 37% in patients treated with trastuzumab and 6% in those not treated with trastuzumab, a significant difference between the two groups (P < 0.05).

Conclusions

The results of this study emphasize the significance of confirming HER2 expression in a recurrence lesion. For patients with positive conversion of HER2 status, more treatment options may be available. On the other hand, the rate of loss of HER2 expression was high in patients treated with trastuzumab, suggesting that the results of biopsy may provide an opportunity to reconsider treatment strategies for these patients.     

High circulating HER2 extracellular domain levels correlate with reduced efficacy of an aromatase inhibitor in hormone receptor-positive metastatic breast cancer: a confirmatory prospective study

BACKGROUND: In this specifically designed, prospective study, the authors addressed the predictive value of circulating levels of the extracellular domain (ECD) of HER2 in patients with metastatic breast cancer who were treated with letrozole. METHODS: Two hundred twenty-six patients with hormone receptor-positive, metastatic breast cancer received letrozole (2.5 mg daily) until they developed either disease progression or unacceptable toxicity. Efficacy was measured primarily as the time to progression (TTP) and, secondarily, as the objective response rate (ORR) and overall survival. HER2 ECD levels were determined by using a sandwich enzyme HER2/neu immunoassay before letrozole treatment was initiated. Positive HER2 ECD status was correlated with treatment efficacy. RESULTS: Forty-two patients (19%) had elevated HER2 ECD levels, which were associated with primary tumor HER2 expression (P < .001) but not with age, performance status, location, or number of metastatic sites. The median TTP was significantly shorter among patients who had elevated HER2 ECD compared with the median TTP among patients who had normal levels (4 months vs 14 months; P = .0004), and the ORR was lower in the group with elevated HER2 ECD levels (14% vs 30%; P < .036). Overall survival was significantly shorter among patients with elevated serum HER-2 ECD (P < .0005). CONCLUSIONS: Elevated HER2 ECD concentrations predicted poorer outcomes in postmenopausal women with metastatic hormone receptor-positive breast cancer who were treated with aromatase inhibitors like letrozole.     

Safety and efficacy of neratinib in combination with weekly paclitaxel and trastuzumab in women with metastatic HER2-positive breast cancer: an NSABP Foundation Research Program phase I study

Purpose

Neratinib is an oral, small-molecule inhibitor that irreversibly binds to pan-HER (ErbB) receptor tyrosine kinases. Studies suggest that dual anti-HER therapies utilized in breast cancer patients are more efficacious than single agents in both the metastatic and neoadjuvant settings. In this phase I study, neratinib was combined with trastuzumab and paclitaxel in metastatic HER2-positive patients.

Methods

Twenty-one patients entered this dose-escalation study to determine the maximum-tolerated dose, safety, and efficacy of neratinib (120 up to 240 mg/day) with trastuzumab (4 mg/kg IV loading dose, then 2 mg/kg IV weekly), and paclitaxel (80 mg/m² IV days 1, 8, and 15 of a 28-day cycle) in women with HER2-positive metastatic breast cancer previously treated with anti-HER agent(s) and a taxane.

Results

The recommended phase II dose of neratinib with trastuzumab and paclitaxel was 200 mg/day. Common grade 3/4 adverse events were diarrhea (38 %), dehydration (14 %), electrolyte imbalance (19 %), and fatigue (19 %). With mandated primary diarrheal prophylaxis, ≥grade 3 diarrhea was not observed. Objective responses, complete (CR) and partial (PR), occurred in eight patients (38 %), with a clinical benefit of CR + PR+ stable disease (SD) ≥24 weeks in 11 patients (52 %). Median time-to-disease progression was 3.7 months.

Conclusions

Dual anti-HER blockade with neratinib and trastuzumab resulted in significant clinical benefit despite prior exposure to trastuzumab, lapatinib, T-DM1, a taxane, and multiple lines of chemotherapy. In selected populations, inhibiting multiple ErbB-family receptors may be more advantageous than single-agent inhibition. Based on favorable tolerance and efficacy, this three-drug combination will be further assessed in a randomized phase II neoadjuvant trial (NSABP FB-7:NCT01008150).     

Weekly trastuzumab and paclitaxel therapy for metastatic breast cancer with analysis of efficacy by HER2 immunophenotype and gene amplification.

PURPOSE: This phase II study evaluated weekly trastuzumab and paclitaxel therapy in women with HER2-normal and HER2-overexpressing metastatic breast cancer. Efficacy was correlated with immunohistochemical and fluorescent in situ hybridization (FISH) assay results. PATIENTS AND METHODS: Eligible patients had bidimensionally measurable metastatic breast cancer. Up to three prior chemotherapy regimens, including prior anthracycline and taxane therapy, were allowed. Trastuzumab 4 mg/kg and paclitaxel 90 mg/m2 were administered on week 1, with trastuzumab 2 mg/kg and paclitaxel 90 mg/m2 administered on subsequent weeks. HER2 status was evaluated using four different immunohistochemical assays and FISH. RESULTS: Patients received a median of 25 weekly infusions (range, one to 85 infusions). Median delivered paclitaxel dose-intensity was 82 mg/m2/wk (range, 52 to 90 mg/m2/wk). The intent-to-treat response rate for all 95 patients enrolled was 56.8% (95% confidence interval, 47% to 67%). A response rate of 61.4% (4.5% complete response, 56.8% partial response) was observed in 88 fully assessable patients. In patients with HER2-overexpressing tumors, overall response rates ranged from 67% to 81% compared with 41% to 46% in patients with HER2-normal expression (ranges reflect the different assay methods used to assess HER2 status). Differences in response rates between patients with HER2-overexpressing tumors and those with normal HER2 expression were statistically significant for all assay methods, with CB11 and TAB250 antibodies and FISH having the strongest significance. Therapy was generally well tolerated, although three patients had serious cardiac complications. CONCLUSION: Weekly trastuzumab and paclitaxel therapy is active in women with metastatic breast cancer. Therapy was relatively well tolerated; however, attention to cardiac function is necessary.     

Phase II study evaluating lapatinib in combination with nab-paclitaxel in HER2-overexpressing metastatic breast cancer patients who have received no more than one prior chemotherapeutic regimen

Lapatinib, an oral, reversible inhibitor of epidermal growth factor receptor and human epidermal growth factor receptor 2 (HER2) tyrosine kinase, has proven antitumor activity in HER2-positive metastatic breast cancer (MBC). Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is indicated for the treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy. This was an open-label, single-arm, multicenter, Phase II study to evaluate the efficacy and safety of nab-paclitaxel plus lapatinib in women with HER2 over-expressing MBC who had received no more than one prior chemotherapeutic regimen. The primary efficacy endpoint was the overall response rate (ORR). This was defined as the percentage of patients having either a complete response (CR) or partial response (PR). Secondary efficacy endpoints included progression-free survival (PFS), overall survival, duration of response (DoR), time to response (TTR), and time to progression (TTP). Investigator-assessed ORR was 53 % (n = 32, 95 % confidence interval (CI): 40.7–66.0) with the majority of patient responses demonstrating a PR (47 %). Four (7 %) patient responses demonstrated a CR, and ten (17 %) a stable disease. The median Kaplan–Meier estimate of investigator-assessed PFS, DoR, TTR, and TTP was 39.7 weeks (95 % CI 34.1–63.9), 48.7 weeks (95 % CI 31.7–57.1), 7.8 weeks (95 % CI 7.4–8.1), and 41 weeks (95 % CI 39.1–64.6), respectively. Lapatinib 1,000 mg with nab-paclitaxel 100 mg/m² IV is feasible with manageable and predictable toxicity and an ORR of 53 % comparing favorably with other HER2-based combinations in this setting.     

Preoperative therapy with trastuzumab and paclitaxel followed by sequential adjuvant doxorubicin/cyclophosphamide for HER2 overexpressing stage II or III breast cancer: a pilot study.

PURPOSE: Trastuzumab combined with chemotherapy improves outcomes for women with human epidermal growth factor receptor 2 (HER2) overexpressing advanced breast cancer. We conducted a pilot study of preoperative trastuzumab and paclitaxel, followed by surgery and adjuvant doxorubicin and cyclophosphamide chemotherapy in earlier stage breast cancer. PATIENTS AND METHODS: Patients with HER2-positive (2+ or 3+ by immunohistochemistry) stage II or III breast cancer received preoperative trastuzumab (4 mg/kg x 1, then 2 mg/kg/wk x 11) in combination with paclitaxel (175 mg/m(2) every 3 weeks x 4). Patients received adjuvant doxorubicin and cyclophosphamide chemotherapy following definitive breast surgery. Clinical and pathologic response rates were determined after preoperative therapy. Left ventricular ejection fraction and circulating levels of HER2 extracellular domain were measured serially. RESULTS: Preoperative trastuzumab and paclitaxel achieved clinical response in 75% and complete pathologic response in 18% of the 40 women on study. HER2 3+ tumors were more likely to respond than 2+ tumors (84% v 38%). No unexpected treatment-related noncardiac toxicity was encountered. Four patients developed grade 2 cardiotoxicity (asymptomatic declines in left ventricular ejection fraction). Baseline HER2 extracellular domain was elevated in 24% of patients and declined with preoperative therapy. Immunohistochemical analyses of posttherapy tumor specimens indicated varying patterns of HER2 expression following trastuzumab-based treatment. CONCLUSION: Preoperative trastuzumab and paclitaxel is active against HER2 overexpressing early-stage breast cancer and may be feasible as part of a sequential treatment program including anthracyclines. The observed changes in cardiac function merit further investigation. Correlative analyses of HER2 status may facilitate understanding of tumor response and resistance to targeted therapy.     

Trastuzumab (Herceptin) in the treatment of breast cancer with HER2 overexpression

HER2 is a 185 kDa transmembrane receptor with tyrosine kinase activity encoded by the HER2/neu gene. HER2 is overexpressed in 25%–30% of breast cancer and confers an agressive clinic course. Trastuzumab (Herceptin) is a monoclonal antibody directed against HER2 receptor that has a favorable toxicity profile and produces responses as a single agent in women with metastatic breast cancer with HER2 overexpression. A multicenter phase III trial in HER2 positive metastatic breast cancer, compared first line chemotherapy with adriamycin/cyclophosphamide or paclitaxel alone or the same chemotherapy plus trastuzumab. Response rate, duration of response and time to progression, were better with the combination. Remarkably, overall survival was significantly improved in patients with trastuzumab and chemotherapy. These studies led to the approval of trastuzumab for HER2 positive metastatic breast cancer. Ongoing trials are analyzing new combinations of trastuzumab and chemotherapy or hormonal therapy. The role of trastuzumab in adjuvant and neoadjuvant therapy is also under investigation.      

Phase II Trial of Weekly Nanoparticle Albumin-Bound Paclitaxel With Carboplatin and Trastuzumab as First-line Therapy for Women With HER2-Overexpressing Metastatic Breast Cancer

PurposeThis multicenter phase II trial evaluated the efficacy and safety of weekly nanoparticle albumin-bound paclitaxel with carboplatin and weekly trastuzumab as first-line therapy for women with HER2-overexpressing metastatic breast cancer (MBC).Patients and MethodsWe treated 32 patients who had measurable MBC that was HER2-positive defined by an immunohistochemical staining score of 3+ or gene amplification by fluorescence in situ hybridization, required for those with an IHC of 2+. Patients were treated with albumin-bound paclitaxel 100 mg/m² and carboplatin at area under the curve (AUC) = 2 on days 1, 8, and 15 of a 28-day cycle. Trastuzumab was administered at 2 mg/kg weekly after a loading dose of 4 mg/kg. Because of hypersensitivity reactions occurring during carboplatin infusion numbers 6–8 in 4 of the first 13 patients with this premedication-free regimen, the protocol was amended for carboplatin and dosed at AUC = 6 day 1 each 28-day cycle, in lieu of introducing steroid prophylaxis. Patients were treated with 6 cycles and allowed to continue with all 3 drugs or trastuzumab alone if free of progression and unacceptable toxicity after 6 cycles.ResultsThe overall response rate (ORR) was 62.5% (95% CI, 45.7%–79.3%) with 3 confirmed complete responders (CRs; 9%) and 17 confirmed partial responses (PRs; 53%). An additional 6 patients (19%) had stable disease (SD) for greater than 16 weeks for a clinical benefit rate (ORR + SD > 16 weeks) of 81%. As of April 16, 2009, 20 patients (63%) had progressed with a median progression-free survival (PFS) of 16.6 months (95% CI, 7.5-26.5 months). Antitumor activity was similar for patients treated with weekly carboplatin and every-4-week carboplatin (ORR, 65% vs. 67%, respectively). Hematologic toxicities were the only grade 4 toxicities noted and were infrequent with grade 4 neutropenia in 3 patients (9%) and 1 febrile neutropenia. Grade 2/3 peripheral neuropathy was uncommon (13%/3%).ConclusionWeekly albumin-bound paclitaxel with carboplatin and trastuzumab is highly active in HER2-overexpressing MBC. In the absence of corticosteroid premedication, which we avoided with albumin-bound paclitaxel, carboplatin seems best dosed every 4 weeks rather than weekly because of carboplatin-associated hypersensitivity reactions. The regimen was very well tolerated with few grade 3 and 4 nonhematologic toxicities experienced, and severe hematologic toxicity and peripheral neuropathy were infrequent.