Therapeutic approaches for HER2-positive brain metastases: Circumventing the blood–brain barrier

We aim to summarize data from studies of trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)–positive metastatic breast cancer (MBC) and brain metastasis and to describe novel methods being developed to circumvent the blood–brain barrier (BBB). A literature search was conducted to obtain data on the clinical efficacy of trastuzumab and lapatinib in patients with HER2-positive MBC and brain metastasis, as well as the transport of therapeutic molecules across the BBB. Trastuzumab-based therapy is the standard of care for patients with HER2-positive MBC. Post hoc and retrospective analyses show that trastuzumab significantly prolongs overall survival when given after the diagnosis of central nervous system (CNS) metastasis; this is probably attributable to its control of extracranial disease, although trastuzumab may have a direct effect on CNS disease in patients with local or general perturbation of the BBB. In patients without a compromised BBB, trastuzumab is thought to have limited access to the brain, because of its relatively large molecular size. Several approaches are being developed to enhance the delivery of therapeutic agents to the brain. These include physical or pharmacologic disruption of the BBB, direct intracerebral drug delivery, drug manipulation, and coupling drugs to transport vectors. Available data suggest that trastuzumab extends survival in patients with HER2-positive MBC and brain metastasis. Novel methods for delivery of therapeutic agents into the brain could be used in the future to enhance access to the CNS by trastuzumab, thereby improving its efficacy in this setting.     

HER2 discordance between primary and metastatic breast cancer: Assessing the clinical impact

Background

In the setting of breast cancer relapse, treatment decisions are typically made by utilizing HER2, estrogen, and progesterone receptor expression status of the primary breast cancer. Recently, concern regarding receptor discordance has led to recommendations for rebiopsy for all cases of metastatic disease. However, whether this is an appropriate recommendation is uncertain, particularly as the clinical implications for HER2 discordance are unknown.

Methods

We performed a literature review to identify studies assessing HER2 discordance between primary and metastatic breast cancer. These studies were then reviewed for data relating to (1) impact of clinical factors on discordance rates, (2) prognostic impact of discordance, or (3) clinical outcomes from treatment alteration due to receptor discordance. Results were analyzed qualitatively.

Results

From 60 HER2 discordance studies identified, 24 contained information of interest for this review. No clear factor promoting HER2 discordance was identified. Loss of HER2 seemed to result in worse post-relapse survival and overall survival, although these data were often confounded by lack of treatment in the setting of receptor loss. Conversely, HER2 discordance was not associated with shorter DFS. Individual patients with receptor gain appear to have benefited from addition of targeted treatment, although data are limited to case reports.

Conclusion

Evidence of HER2 discordance leading to alterations in patient outcomes is limited, highlighting the need for further research in this area. Furthermore, lack of alteration in patient outcomes suggests that a more pragmatic approach to the decision to rebiopsy may be appropriate.     

仙蟾片联合曲妥珠单抗和mFOLFOX6方案治疗老年HER2阳性晚期胃癌的临床研究

目的观察仙蟾片联合曲妥珠单抗和mFOLFOX6方案治疗老年表皮生长因子受体-2(HER2)阳性晚期胃癌的临床疗效。方法选取2011年1月—2014年1月在延安市人民医院就诊的老年HER2阳性晚期胃癌患者212例,随机分为对照组和治疗组,每组各106例。两组患者均给予mFOLFOX6方案化疗,每个治疗周期为21 d。对照组在此基础上于第1天静脉滴注注射用曲妥珠单抗8 mg/kg,然后每个周期第1天给予6 mg/kg。治疗组在对照组的基础上口服给予仙蟾片,4片/次,3次/d。两组患者均治疗6个周期。观察两组患者近期和远期疗效,同时比较治疗前后两组患者血清生化指标和不良反应。结果治疗后,对照组临床有效率和控制率分别为60.3%、78.3%,均显著低于治疗组的73.5%、89.6%,两组比较差异具有统计学意义(P0.05)。治疗后,两组患者血清纤维母细胞特异性蛋白-1(FSP-l)、骨髓相关蛋白-14(MRP-l4)、趋化因子受体-4(CXCR4)和基质衍生因子-1(SDF-1)均明显降低(P0.05),且治疗组上述血清生化指标明显低于对照组(P0.05)。远期疗效结果显示,对照组有效病例中平均无疾病进展生存时间(PFS)和总生存时间(OS)均分别明显小于治疗组患者,两组比较差异具有统计学意义(P0.05)。治疗期间,治疗组的不良反应发生率均明显低于对照组,两组比较差异具有统计学意义(P0.05)。结论仙蟾片联合曲妥珠单抗和mFOLFOX6方案治疗老年人表皮生长因子受体-2(HER2)阳性晚期胃癌患者临床疗效较好,能够有效延长生存时间,具有一定的临床推广应用价值。     

曲妥珠单抗与拉帕替尼联合用于乳腺癌新辅助治疗的随机对照研究的 Meta 分析

目的：比较单用曲妥珠单抗与曲妥珠单抗和拉帕替尼两药联合在 HER2阳性乳腺癌新辅助治疗中的有效性和安全性。方法检索 PubMed、MEDLINE、The Cochrane Library、Web of Science、中国期刊全文数据库、万方医药期刊全文数据库和近5年重要国际肿瘤学会议记录,严格按照纳入与排除标准收集 HER2阳性乳腺癌患者使用新辅助化疗联合曲妥珠单抗对比新辅助化疗联合曲妥珠单抗、拉帕替尼双重抗 HER2治疗的有效性和安全性的前瞻性随机对照研究,按 Cochrane 系统评价方法进行质量评价,资料提取后运用 Rev-Man 5.0软件进行 Meta 分析。结果最终纳入4项临床随机对照试验,共779例患者符合条件。Meta分析结果显示,曲妥珠单抗联合拉帕替尼组较单独使用曲妥珠单抗组病理完全缓解率显著升高（53.3%：38.8%, RR =1.39,95%CI 为1.20~1.63,P <0.001）;Ⅲ~Ⅳ级不良反应方面,除了联合组的腹泻发生率更高（25.6%：2.2%,RR =11.54,95%CI 为5.69~23.41,P <0.001）以外,其他差异均无统计学意义。结论在 HER2阳性乳腺癌患者的新辅助治疗中采用新辅助化疗联合曲妥珠单抗、拉帕替尼的双重抗 HER2靶向治疗效果较好,且除了腹泻外并不提高其他不良反应发生率,是一种高效、安全的治疗选择。     

Multicenter phase II study of trastuzumab in combination with capecitabine and oxaliplatin for advanced gastric cancer

BackgroundTrastuzumab has been approved for use in combination with fluoropyrimidine plus cisplatin for the treatment of human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC). Although capecitabine plus oxaliplatin (XELOX) is a standard first-line regimen for AGC, combination trastuzumab plus XELOX has not been studied.MethodsPatients with metastatic or unresectable HER2-positive AGC were diagnosed by either HER2 immunohistochemistry (IHC) 3+ or IHC 2+/fluorescence in-situ hybridisation (FISH)+ received intravenous trastuzumab (8 mg/kg for first cycle and 6 mg/kg for subsequent cycles on day 1) plus oral capecitabine (1000 mg/m² twice daily on days 1–14) and intravenous oxaliplatin (130 mg/m² on day 1), every 3 weeks. The primary end-point was the objective response rate, and secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity profiles.ResultsFifty-five HER2-positive AGC patients were enrolled between August 2011 and February 2013. The median age was 57 years (range = 29–74). The confirmed objective response rate was 67% (95% confidence interval (CI) = 54–80%). After a median follow-up period of 13.8 months (range = 6.1–23.9), the median PFS and OS were 9.8 months (95% CI = 7.0–12.6) and 21.0 months (95% CI = 6.4–35.7), respectively. Frequently encountered grade 3–4 toxicities included neutropenia (18%), anaemia (11%), and peripheral neuropathy (11%). There was a treatment-related death caused by severe diarrhoea and complicated sepsis.ConclusionCombination of trastuzumab and XELOX is well tolerated and highly effective in patients with HER2-positive AGC.     

Potential biomarkers of long‐term benefit from single‐agent trastuzumab or lapatinib in HER2‐positive metastatic breast cancer

In 2009 a prospective, randomized Phase II trial ({"type":"clinical-trial","attrs":{"text":"NCT00842998","term_id":"NCT00842998"}}NCT00842998) was initiated to evaluate the activity of HER2‐targeting agents without chemotherapy (CT) in HER2‐positive metastatic breast cancer (MBC) patients. The primary tumors of the patients enrolled in this study offered a unique opportunity to identify biomarkers that could predict durable clinical benefit from CT‐free anti‐HER2 therapy.Patients with HER2‐positive MBC were randomized to trastuzumab or lapatinib as first‐line therapy. CT was added to anti‐HER2 therapy in patients failing to achieve tumor regression at the 8‐week evaluation and in those progressing at any time. Expression analysis of 105 selected genes was performed from formalin‐fixed paraffin‐embedded primary tumor samples. The research‐based PAM50 intrinsic subtypes were also identified. Additionally, quantitative HER2 (H2T) and p95HER2 (p95) protein expression were evaluated by HERmark® and VeraTag® assay, respectively. Predictors of persistence on protocol (PP) were studied by Cox univariate and multivariate analysis.Nineteen patients were enrolled. Median overall survival was 43 months and median PP was 3.8 months (0.8–38.8+), with 4 patients (21.1%) persisting on single agent trastuzumab or lapatinib for longer than 12 mo (14.9–38.8 + mo). Seventeen patients were evaluable for PP. Gene expression analysis revealed that high expression of the 17q12‐21 amplicon genes HER2 and GRB7, and the PAM50 HER2‐enriched intrinsic profile, were significantly associated with longer PP. Conversely, high expression of luminal‐related genes such as PGR, MDM2 or PIK3CA, or the PAM50 luminal intrinsic profile correlated with reduced PP. Moreover, increasing H2T/p95 ratio was found to be significantly associated with longer PP (HR 0.56 per 2‐fold increase in H2T/p95, P = 0.0015).Our data suggest that patients belonging to the “HER2‐enriched” subtype and/or having high H2T/p95 protein expression ratio are exquisitely sensitive to anti‐HER2 agents. MBC patients with these tumors could be candidates for studies aimed at establishing chemotherapy‐free regimens.     

胃癌HER2信号通路及曲妥珠单抗临床应用进展

胃癌是全世界常见的消化系统恶性肿瘤之一,是我国第二大肿瘤,5年生存率不足20%。近年来,肿瘤的分子分型与分子靶向治疗方兴未艾,在肺癌、乳腺癌、大肠癌等肿瘤中已初见成效,用于临床治疗指导,疗效预测及预后判断。而胃癌的靶向治疗却迟迟未见端倪,     

抗Trastuzumab单克隆抗体制备及其双抗体夹心ELISA检测方法的建立

本研究利用曲妥珠单抗(Trastuzumab)4次腹腔免疫 6-8 周龄BALB/c 雌性小鼠.通过淋巴细胞杂交瘤技术、间接ELISA 筛选技术及腹水制备等技术制备并获得抗Trastuzumab单克隆抗体.试验结果表明,通过细胞融合获得了一株能稳定分泌抗Trastuzumab的杂交瘤细胞株A6E8,其制备的腹水单克隆抗体纯化后效价为256000,该抗体属于IgG1亚类,链的类型为k链.利用制备的单克隆抗体(McAb)建立Trastuzumab双抗体夹心ELISA检测方法,试验结果显示,该检测方法特异性良好,不与其他抗体及蛋白发生交叉反应,所建立的Trastuzumab双抗体夹心ELISA 方法最低检测限为1ng/mL.     

Risk of cardiac dysfunction with trastuzumab in breast cancer patients: a meta-analysis

Background

Trastuzumab is used widely for the treatment of early and advanced breast cancer. However, concerns have arisen regarding its cardiac toxicity. We did a systematic review and meta-analysis of published randomized controlled trials (RCTs) to assess the overall risk of cardiac dysfunction associated with trastuzumab treatment.

Methods

We searched PubMed and Web of Science (January 1966-July 2009) and American Society of Clinical Oncology conferences held (January 2000-July 2009) for relevant articles and abstracts. Summary incidence rates, relative risks (RRs), and 95% confident intervals (CIs) were calculated using a fixed-effects or random-effects model.

Results

11,882 patients from 10 RCTs were included for analysis. The incidences of LVEF decrease and congestive heart failure (CHF) were 7.5% (95% CI 4.2-13.1) and 1.9% (95% CI 1.0-3.8) among patients receiving trastuzumab. Trastuzumab significantly increased the risk of LVEF decrease (RR = 2.13, 95% CI, 1.31-3.49; p = 0.003). In addition, it significantly increased the risk of CHF (RR = 4.19, 95% CI 2.73-6.42; p < 0.00001). The increased risk of CHF was observed in patients with early stage (RR = 4.05, 95% CI 2.49-6.58; p < 0.00001) as well as metastatic disease (RR = 4.75, 95% CI 1.93-11.71; p = 0.0007). Furthermore, trastuzumab significantly increased the risk of CHF (RR = 4.27, 95% CI 2.75-6.61, p < 0.00001) in patients receiving anthracycline-based chemotherapy, but not in patients receiving non-anthracycline chemotherapy (RR = 2.42, 95% CI 0.36-16.19, p = 0.36).

Conclusion

The addition of trastuzumab to anthracycline-based chemotherapy significantly increase the risk of cardiac dysfunction in breast cancer patients. Further studies are recommended for non-anthracycline chemotherapy.