Contextualizing pertuzumab approval in the treatment of HER2-positive breast cancer patients

The use of adjuvant pertuzumab in HER2-positive early-stage breast cancer has recently been approved by the EMA on the basis of data from the APHINITY trial. Accordingly, we have produced this opinion article with the aim of putting the study data in perspective against other add-on therapeutic strategies, to clarify methodological or statistical doubts about the study, and to define the population of high-risk patients with hormone receptor-negative breast cancer that we agree, in general, should be treated. With this approval, physicians must be well prepared to place the APHINITY study data in context. It is now up to each country to ratify the EMA-approved indications and to agree on reimbursement, and doctors must optimize their use based on knowledge and discussion with patients.     

帕妥珠单抗在HER-2阳性乳腺癌治疗中的临床转化

帕妥珠单抗(pertuzumab)作为一种新的抗人表皮生长因子受体-2(human epidermal growth factor receptor,HER-2)治疗药物,其作用区域不同于曲妥珠单抗,两者联合可以发挥更全面的HER-2抑制作用,基础和临床转化研究均证实帕妥珠单抗和曲妥珠单抗有协同的抗肿瘤作用.Ⅱ期和Ⅲ期临床转化试验结果显示,抗HER-2两药治疗(帕妥珠单抗+曲妥珠单抗)联合化疗可使HER-2阳性晚期乳腺癌的中位无疾病进展时间(progression-free survival,PFS)延长到18个月以上,中位总生存时间(overall survival,OS)接近5年(56.5个月),显著改善了晚期HER-2阳性乳腺癌患者的预后.两项Ⅱ期新辅助治疗临床转化研究也确认帕妥珠单抗联合曲妥珠单抗的协同作用疗效同样突出,病理完全缓解(pathological complete response,pCR)率最高可达66.2％.安全性分析发现,即使是与蒽环类药物联用,加用帕妥珠单抗治疗也并未增加心脏毒性.本文对帕妥珠单抗在HER-2阳性乳腺癌治疗中的上述相关临床转化研究进行综述.     

HER2 mutation status in Japanese HER2-positive breast cancer patients

Background

Human epidermal growth factor receptor 2 (HER2) gene amplification/overexpression is a major therapeutic target in breast cancer, and has been introduced as a predictive biomarker to identify patients who may benefit from therapy with anti-HER2 agents. HER2 somatic mutations have been reported, and these may influence the effect of HER2-targeted drugs.

Methods

Here, we sought HER2 mutations in a group of 135 Japanese breast cancer patients with HER2-positive tumors. We analyzed HER2 mutations by direct Sanger sequencing of two major areas, the extracellular domain at position 309–310 and the kinase domain between 755 and 781.

Results

Two patients with the HER2 somatic mutation S310F in the extracellular domain were found in this series. One patient with the S310F mutation had a node-negative invasive ductal carcinoma classified as HER2 2+ by the HercepTest and fluorescence in situ hybridization (FISH) positive, and which was estrogen receptor (ER)-negative and progesterone receptor (PgR)-negative. Another patient with the S310F mutation had an apocrine carcinoma with seven lymph nodes positive for metastasis, classified as HER2 3+ by the HercepTest, but which was FISH-negative, as well as ER-negative and PgR-negative. Both patients had received adjuvant single-agent trastuzumab therapy, and had no local recurrence or distant metastasis for five and three years after surgery, respectively.

Conclusions

Our data show that HER2 mutations are rare in HER2-positive Japanese breast cancer patients. The two mutations found in this study were identical, S310F. We suggest that in vitro experiments to determine whether the S310F mutation could be involved in resistance to anti-HER2 drugs are worthwhile in future.

     

Factors influencing survival among patients with HER2-positive metastatic breast cancer treated with trastuzumab

Background

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2–3 years from tamoxifen to exemestane. This PathIES aimed to assess the role of immunohistochemical (IHC)4 score in determining the relative sensitivity to either tamoxifen or sequential treatment with tamoxifen and exemestane.

Patients and methods

Primary tumour samples were available for 1274 patients (27% of IES population). Only patients for whom the IHC4 score could be calculated (based on oestrogen receptor, progesterone receptor, HER2 and Ki67) were included in this analysis (N = 430 patients). The clinical score (C) was based on age, grade, tumour size and nodal status. The association of clinicopathological parameters, IHC4(+C) scores and treatment effect with time to distant recurrence-free survival (TTDR) was assessed in univariable and multivariable Cox regression analyses. A modified clinical score (PathIEscore) (N = 350) was also estimated.

Results

Our results confirm the prognostic importance of the original IHC4, alone and in conjunction with clinical scores, but no significant difference with treatment effects was observed. The combined IHC4 + Clinical PathIES score was prognostic for TTDR (P < 0.001) with a hazard ratio (HR) of 5.54 (95% CI 1.29–23.70) for a change from 1st quartile (Q1) to Q1–Q3 and HR of 15.54 (95% CI 3.70–65.24) for a change from Q1 to Q4.

Conclusion

In the PathIES population, the IHC4 score is useful in predicting long-term relapse in patients who remain disease-free after 2–3 years. This is a first trial to suggest the extending use of IHC4+C score for prognostic indication for patients who have switched endocrine therapies at 2–3 years and who remain disease-free after 2–3 years.

     

Incidence of central nervous system metastases in patients with HER2-positive metastatic breast cancer treated with pertuzumab,trastuzumab, and docetaxel: results from the randomized phase III study CLEOPATRA

BackgroundResults from the phase III trial CLEOPATRA in human epidermal growth factor receptor 2-positive first-line metastatic breast cancer demonstrated significant improvements in progression-free and overall survival with pertuzumab, trastuzumab, and docetaxel over placebo, trastuzumab, and docetaxel. We carried out exploratory analyses of the incidence and time to development of central nervous system (CNS) metastases in patients from CLEOPATRA.Patients and methodsPatients received pertuzumab/placebo: 840 mg in cycle 1, then 420 mg; trastuzumab: 8 mg/kg in cycle 1, then 6 mg/kg; docetaxel: initiated at 75 mg/m². Study drugs were administered i.v. every 3 weeks. The log-rank test was used for between-arm comparisons of time to CNS metastases as first site of disease progression and overall survival in patients with CNS metastases as first site of disease progression. The Kaplan–Meier approach was used to estimate median time to CNS metastases as first site of disease progression and median overall survival.ResultsThe incidence of CNS metastases as first site of disease progression was similar between arms; placebo arm: 51 of 406 (12.6%), pertuzumab arm: 55 of 402 (13.7%). Median time to development of CNS metastases as first site of disease progression was 11.9 months in the placebo arm and 15.0 months in the pertuzumab arm; hazard ratio (HR) = 0.58, 95% confidence interval (CI) 0.39–0.85, P = 0.0049. Overall survival in patients who developed CNS metastases as first site of disease progression showed a trend in favor of pertuzumab, trastuzumab, and docetaxel; HR = 0.66, 95% CI 0.39–1.11. Median overall survival was 26.3 versus 34.4 months in the placebo and pertuzumab arms, respectively. Treatment comparison of the survival curves was not statistically significant for the log-rank test (P = 0.1139), but significant for the Wilcoxon test (P = 0.0449).ConclusionsWhile the incidence of CNS metastases was similar between arms, our results suggest that pertuzumab, trastuzumab, and docetaxel delays the onset of CNS disease compared with placebo, trastuzumab, and docetaxel.ClinicalTrials.govNCT00567190.     

Outcomes of HER2-positive non-metastatic breast cancer patients treated with anti-HER2 therapy without chemotherapy

Breast Cancer Research and Treatment - Anti-HER2 therapy delivered in the adjuvant setting for breast cancer is given in conjunction with cytotoxic chemotherapy. For HER2-positive (HER2+) patients...     

Phase 2 prospective open label study of neoadjuvant nab-paclitaxel,trastuzumab, and pertuzumab in patients with HER2-positive primary breast cancer

Background

The objective of this study was to evaluate the safety and efficacy of nab-paclitaxel, trastuzumab, and pertuzumab as neoadjuvant therapy (NAT) in patients with human epidermal growth factor receptor 2 HER2+ breast cancer (HER2+ BC) to determine pathologic complete response (pCR), invasive disease-free survival (iDFS), and overall survival.

Methods

Forty-five patients with HER2+ BC Stages II–III were to be enrolled from 2013 to 2017. Patients were treated with weekly nab-paclitaxel (100 mg/m² intravenously), weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg), and six cycles of pertuzumab (840 mg loading dose, then 420 mg intravenously day 1 every 21 days).

Results

Median follow-up was 60 months (95% CI, 32.3–55.6) and pCR was 29/45 (64%). The 5-year iDFS for patients who achieved pCR (N = 29) was 96.3% (95% CI, 76.5–99.5) and non-pCR patients (N = 16) was 74.3% (95% CI, 39.1–91.0). The 5-year overall survival (N = 45) was 94.1% (95% CI, 77.6–98.5). Based on hormonal status, the 5-year iDFS for HR+ pCR patients (N = 14) was 92.3% (95% CI, 56.6–98.9) and for HR− (N = 15) was 100% (p = .3).

Conclusions

This anthracycline/carboplatin-free regimen with nab-paclitaxel achieved a pCR rate of 64% in patients with HER2+ BC. The 5-year iDFS in patients with and without pCR was 96.3% and 74.3%, respectively. The pCR rate is comparable with docetaxel, carboplatin, trastuzumab, and pertuzumab therapy in the NAT setting, but with fewer treatment-associated toxicities. This finding suggests the possibility of safe avoidance of anthracyclines and carboplatin as components of NAT in patients with HER2+ BC.     

HER2-positive advanced breast cancer

It is important when treating a patient who has advanced breast cancer to establish the biologic characteristics of the tumor. In addition to knowing the hormone receptor status (estrogen and progesterone), human epidermal receptor 2 (HER2) should be evaluated. The measurement of this parameter is essential to optimizing the systemic management. This article reviews the biology of HER2, testing for HER2, clinical studies evaluating HER2-based therapies, side effects (specifically cardiotoxicity), and strategies for HER2-based therapies.     

CLEOPATRA: a phase III evaluation of pertuzumab and trastuzumab for HER2-positive metastatic breast cancer

IntroductionPatients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer have a poor prognosis. Despite proven efficacy with the standard of care, trastuzumab, most patients with HER2-positive metastatic breast cancer (MBC) will eventually progress, requiring further intervention to prolong life. Pertuzumab, a humanized monoclonal antibody, is the first HER2 dimerization inhibitor. It binds to the dimerization site on the HER2 domain and prevents ligand-driven pairing of HER2 with other HER receptors, thus inhibiting tumor cell growth and survival. Combining trastuzumab and pertuzumab therefore provides a more comprehensive blockade of the HER signaling pathways, resulting in greater antitumor efficacy.Study DesignCLEOPATRA (CLinical Evaluation Of Pertuzumab And TRAstuzumab) is an international, randomized, double-blind, placebo-controlled phase III trial that aims to recruit approximately 800 patients from around 250 centers worldwide. Adults with HER2-positive adenocarcinoma of the breast with locally recurrent or metastatic disease will be randomized (1:1) to receive docetaxel, trastuzumab, and pertuzumab or docetaxel, trastuzumab, and placebo. The primary endpoint of the study is progression-free survival (PFS), based on tumor assessments conducted by an independent review facility. Secondary endpoints include PFS evaluated by investigator assessment, overall survival, objective response rate, duration of response, time to symptom progression, and safety. Data will also be collected to identify biomarkers that may correlate with clinical outcomes.ConclusionThe CLEOPATRA study will provide important information about the efficacy and safety of adding pertuzumab to one current standard of care in patients with HER2-positive MBC.     

HER2阳性乳腺癌治疗的研究进展

[摘要] 人表皮生长因子受体2（human epidermal growth factor receptor 2,HER2）阳性乳腺癌侵袭性高,预后差。随着抗HER2药物的不断出现及广泛应用,HER2 阳性乳腺癌患者的预后出现了非常显著的改善。10 年随访结果证实1 年曲妥珠单抗辅助治疗可以显著降低疾病复发风险;对于术后的高危人群,曲妥珠单抗联合帕妥珠单抗或者曲妥珠单抗序贯来那替尼可以进一步减少复发。5 年随访结果表明帕妥珠单抗+曲妥珠单抗为基础的新辅助治疗可使病理完全缓解（pathological complete response,pCR）转化为长期生存获益;白蛋白紫杉醇代替普通紫杉醇与抗HER2 药物联用可以进一步提高pCR率;而抗HER2 药物联合内分泌治疗尚不能达到与联合化疗在新辅助治疗中疗效,即使联合CDK4/6 抑制剂,对于pCR的提高依然有限。曲妥珠单抗+帕妥珠单抗联合紫杉类药物是晚期HER2 阳性乳腺癌的标准一线方案;对于老年、体弱的患者,节拍环磷酰胺可以作为紫杉类药物的替代品;拉帕替尼+曲妥珠单抗联合内分泌治疗可以作为HER2 阳性伴激素受体阳性的选择,疗效优于曲妥珠单抗联合内分泌治疗;T-DM1 无论是作为二线治疗还是三线及以后的治疗均提高了患者生存获益,是治疗晚期、耐药HER2阳性乳腺癌的首选。     

Clinical outcome of patients with brain metastases from HER2-positive breast cancer treated with lapatinib and capecitabine

BackgroundIn the present study, we investigated the clinical outcome of patients with brain metastases (BMs) from human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) treated with lapatinib and capecitabine (LC).MethodsOf 81 HER2+ metastatic BC patients treated with LC at two Italian institutions, 30 patients with BMs eligible for the analysis were identified. All patients were pretreated with trastuzumab for metastatic disease. No patients had received prior lapatinib and/or capecitabine.ResultsMedian age was 45 years (range 24–75) and 26 of 30 patients (86.7%) had received prior cranial radiotherapy. In the 22 patients with BMs evaluable for response, 7 partial responses (31.8%) and 6 disease stabilizations (27.3%) were observed. Overall, the median brain-specific progression-free survival was 5.6 months (95% confidence interval 4.4–6.8). Patients treated with LC had a median overall survival (from the time of development of BMs) significantly longer compared with 23 patients treated with trastuzumab-based therapies only beyond brain progression (27.9 months versus 16.7 months, respectively, P = 0.01).ConclusionsLC is active for BMs from HER2+ BC in patients not pretreated with either lapatinib or capecitabine. The introduction of LC after the development of BMs may further improve survival compared with trastuzumab-based therapies only beyond brain progression.     

Incidence and risk of central nervous system metastases as site of first recurrence in patients with HER2-positive breast cancer treated with adjuvant trastuzumab

BackgroundCentral nervous system (CNS) disease as the site of first relapse after exposure to adjuvant trastuzumab has been reported. We carried out comprehensive meta-analysis to determine the risk of CNS metastases as the first site of recurrence in patients with HER2-positive breast cancer who received adjuvant trastuzumab.MethodsEligible studies include randomized trials of adjuvant trastuzumab administered for 1 year to patients with HER2-positive breast cancer who reported CNS metastases as first site of disease recurrence. Statistical analyses were conducted to calculate the incidence, relative risk (RR), and 95% confidence intervals (CIs) using fixed-effects inverse variance and random-effects models.ResultsA total of 9020 patients were included. The incidence of CNS metastases as first site of disease recurrence in HER2-positive patients receiving adjuvant trastuzumab was 2.56% (95% CI 2.07% to 3.01%) compared with 1.94% (95% CI 1.54% to 2.38%) in HER2-positive patients who did not receive adjuvant trastuzumab. The RR of the CNS as first site of relapse in trastuzumab-treated patients was 1.35 (95% CI 1.02–1.78, P = 0.038) compared with control arms without trastuzumab therapy. The ratio of CNS metastases to total number of recurrence events was 16.94% (95% CI 10.85% to 24.07%) and 8.33% (95% CI 6.49% to 10.86%) for the trastuzumab-treated and control groups, respectively. No statistically significant differences were found based on trastuzumab schedule or median follow-up time. No evidence of publication bias was observed.ConclusionsAdjuvant trastuzumab is associated with a significant increased risk of CNS metastases as the site of first recurrence in HER2-positive breast cancer patients.     

Dual HER2-targeted approaches in HER2-positive breast cancer

Approximately 15–20% of all breast cancers are human epidermal growth factor receptor 2 (HER2) positive, with clinical studies having validated the HER2 receptor tyrosine kinase pathway as an important therapeutic target. Presently, two HER2-targeted therapies are approved by the Food and Drug Administration for treatment of HER2-positive breast cancer: the HER2-targeted humanized monoclonal antibody trastuzumab and the small-molecule tyrosine kinase inhibitor lapatinib. Despite use of these HER2-targeted agents, many patients still experience disease progression. For this reason, numerous new agents and therapeutic strategies are under investigation. Based on preclinical data suggesting synergistic effects from dual therapy targeting HER2, clinical trials that test the effects of combining anti-HER2 agents have been conducted and are ongoing. Here, we review recently presented data from several clinical trials, which indicate that the strategy of combining HER2 blockade therapies can offer greater clinical efficacy, with adverse effects of varying degrees. Specifically, we review new data reported at the 2010 San Antonio Breast Cancer Symposium (SABCS 2010), including the phase II NeoSphere and phase III NeoALTTO clinical trials, and data from three clinical trials reported at the 2011 American Society of Clinical Oncology (ASCO 2011) meeting. Together these trials elucidate the potential role of combining trastuzumab with lapatinib or pertuzumab. We also discuss additional ongoing studies that will help further define the role of dual HER2 blockade therapies and its impact on clinical practice.     

Expression of truncated HER2 and its prognostic value in HER2-positive breast cancer patients

Purpose

The purpose of this work was to assess the truncated form of human epidermal growth factor receptor 2 (HER2) such as p95-HER2 expression in HER2-positive breast cancer (BC) patients who developed metastatic disease after adjuvant treatment with a trastuzumab-containing regimen.

Pertuzumab: new hope for patients with HER2-positive breast cancer

BackgroundHuman epidermal growth factor receptor 2 (HER2) overexpression is detected in approximately 15% to 20% of all breast cancers (BCs). A revolutionary change in the prognosis of this subgroup of patients has occurred since trastuzumab therapy was introduced into daily clinical practice. However, because trastuzumab resistance is common, new molecules with complementary and/or synergistic mechanisms of action have been developed. Pertuzumab is a new anti-HER2 humanized monoclonal antibody that prevents the formation of HER2 dimers.Material and methodsA computer-based literature search was carried out using PubMed (keywords: breast neoplasm, dimerization, HER-2, pertuzumab); data reported at international meetings are included.ResultsThis paper describes pertuzumab's mechanism of action, safety, and role in HER2-positive BCs. It also explores the role of pertuzumab as a single agent or combined with trastuzumab by reviewing data from preclinical research to ongoing clinical trials. Recently published trials, particularly the CLEOPATRA study, highlight the efficacy, tolerability, and increase in disease-free survival associated with this novel agent when combined with trastuzumab.ConclusionThe pertuzumab and trastuzumab anti-HER2 dual blockade is likely to represent a substantial advance for patients with HER2-positive BCs and a new milestone on the way to personalized medicine.     

Serum HER2 testing in patients with HER2-positive breast cancer: the death knell tolls

Determination of the human epidermal growth factor receptor 2 (HER2; also known as ERBB2) status of breast tumours is emphasised in various national guidelines as a necessary step for the diagnosis of breast cancer. As an alternative to tissue-based diagnostic methods, there has been substantial interest in the establishment of an easily accessible serum-based alternative that could be used for prognosis and diagnosis. Detection of serum-soluble-HER2 extracellular domain (ECD) and establishment of its potential clinical usefulness has created much debate. We assessed whether identification of circulating concentrations of HER2 ECD have clinical usefulness for management of patients with HER2-positive breast cancer. We examined data from 63 studies of patients with breast cancer. Prevalence of increased concentrations varied greatly between studies. Some studies showed significant associations between raised concentrations and poor prognosis, poor response to treatments including trastuzumab, or tumour characteristics associated with aggressive disease, whereas others did not. Examination of existing data showed that concentrations of HER2 ECD are not consistently related to patient outcomes; therefore, there is insufficient evidence to support the clinical use of serum HER2 ECD testing. Design and execution of future large-scale trials to investigate the clinical use of HER2 ECD testing, in view of the progressive non-supportive evidence, is not recommended. Oncologists should continue to adhere to national guidelines for determining HER2 status. Furthermore, oncologists should continue to use clinical parameters when making decisions about initiation, continuation, and discontinuation of HER2-targeted treatments.