新型抗Her-2药物T-DM1

T-DM1是新型抗体-药物偶联物,具有曲妥珠单抗类似的生物活性,可特异性的将强效抗微管药物DM1释放至Her-2过表达的肿瘤细胞内。T-DM1单药疗效优于拉帕替尼联合卡培他滨,有望成为Her-2阳性晚期乳腺癌的标准二线治疗药物。比较T-DM1与曲妥珠单抗联合紫杉类药物一线治疗晚期乳腺癌的试验正在进行中。该药是继曲妥珠单抗之后又一种全新的抗Her-2药物。美国FDA正式批准T-DM1作为治疗Her-2阳性晚期乳腺癌患者的药物。      

T-DM1应用于乳腺癌的最新研究进展

T-DM1是由曲妥珠单抗、细胞毒药物DM1通过连接子偶联而成的抗体药物偶联物,具有靶向性和细胞毒杀伤双重抗肿瘤作用,是第4个被FDA批准上市的抗HER-2靶向治疗药物。在HER-2阳性晚期乳腺癌一线、二线以及多线治疗的临床研究中,T-DM1均显示出突出的抗肿瘤活性,且耐受性良好,NCCN指南推荐其作为曲妥珠单抗治疗失败后的二线首选治疗方案。目前正在进行的临床研究将明确T-DM1在早期乳腺癌治疗领域中的地位,以及与其他药物联合的疗效和安全性。本文综述了T-DM1的作用机制、疗效与安全性、与疗效相关的因素、克服耐药的策略以及应用前景,有助于指导T-DM1的临床应用。     

Beyond trastuzumab: novel therapeutic strategies in HER2-positive metastatic breast cancer

The use of trastuzumab, a monoclonal antibody that targets the human epidermal growth factor receptor 2 (HER2) alteration present in 25 to 30% of breast cancers, has been associated with improved survival outcomes in both the adjuvant and metastatic settings. However, despite the robust clinical efficacy of trastuzumab in HER2-positive metastatic breast cancer (MBC), primary and secondary resistance remains a clinical challenge. Although lapatinib has demonstrated modest activity in this setting, trials reported to date have yet to demonstrate improvements in overall survival with its use. Novel therapeutic strategies to circumvent trastuzumab resistance are warranted, and agents targeting the HER, vascular endothelial growth factor, heat shock protein 90, phosphoinositide 3 kinase/Akt/mammalian target of rapamycin, and insulin-like growth factor-1 receptor pathways represent rational approaches in the management of HER2-positive disease. In this review, early-phase and emerging trial data surrounding the use of these promising agents in HER2-positive MBC will be discussed.     

恩美曲妥珠单抗T-DM1在HER2阳性乳腺癌中的研究进展

T-DM1是由人源化单克隆抗体曲妥珠单抗通过连接子和细胞毒性药物DM1偶联形成的一种抗体-药物偶联物,综合了抗体的靶向性和细胞毒性药物的高效杀伤癌细胞特性,发挥双倍抗肿瘤效应的同时又降低了常规化疗药物的毒副反应。多项临床研究探索了T-DM1应用于晚期HER2阳性转移性乳腺癌的解救治疗以及早期HER2阳性乳腺癌的辅助化疗和新辅助化疗的有效性和耐受性,并展现出良好的临床应用前景。本文就T-DM1应用于HER2阳性乳腺癌的最新临床研究进展简要综述。     

Trastuzumab-DM1 is highly effective in preclinical models of HER2-positive gastric cancer

Background

A novel antibody–drug conjugate (trastuzumab-DM1, T-DM1) is currently in clinical trials for patients with trastuzumab resistant HER2-positive breast cancer. Since no clinical data is available from gastric cancer, we studied T-DM1 on HER2-positive human gastric cancer cells and xenograft tumors.

Methods

Effects of T-DM1 were studied in four HER2-positive gastric cancer cell lines (N-87, OE-19, SNU-216 and MKN-7) in vitro. Xenograft tumors from N-87 and OE-19 were studied to determine the effect of T-DM1 in vivo.

Results

T-DM1 was found more effective than trastuzumab in N-87 and OE-19, and moderately effective in MKN-7 cells. On SNU-216 cells both trastuzumab and T-DM1 showed limited efficacy. In xenograft tumor experiments, complete pathological response was observed in all OE-19 xenografted mice and in half of the N-87 xenografted mice. The results were equally good irrespective of the tumor burden at therapy initiation, or preceding trastuzumab treatment. T-DM1 treatment showed direct effects (apoptotic cell death and aberrant mitosis) as well as it mediated antibody-dependent cellular cytotoxcity (ADCC).

Conclusions

T-DM1 showed a promising anti-tumor effect in HER2-positive gastric cancer cell lines in vitro and in vivo, even in tumors which had developed resistance to trastuzumab. T-DM1 therapy may warrant clinical trials for HER2-positive gastric cancer patients.     

恩美曲妥珠单抗在乳腺癌中的临床研究进展

恩美曲妥珠单抗(T-DM1)是曲妥珠单抗、连接头和微管抑制剂组成的抗体偶合物。T-DM1结合了抗体的高效靶向性与细胞毒性药物的高抗肿瘤活性优势,降低了细胞毒性药物的脱靶不良反应。T-DM1应用于人表皮生长因子受体2(HER-2)阳性乳腺癌的新辅助治疗和晚期乳腺癌的解救治疗,极大地改善了乳腺癌患者的预后。越来越多有关T-DM1治疗HER-2阳性乳腺癌及其他实体瘤的临床试验正在开展,期待有更多的阳性结果。     

Population pharmacokinetics of trastuzumab in patients With HER2+ metastatic breast cancer

Purpose: To characterize the population pharmacokinetics of trastuzumab in patients with metastatic breast cancer. Methods: A nonlinear mixed effect model was based on pharmacokinetic data from phase I, II, and III studies of 476 patients. The phase I study enrolled patients with advanced solid tumors. The phase II and III studies enrolled patients with HER2-positive metastatic breast cancer. Patients in the pivotal phase II and III studies were treated with a 4 mg/kg loading dose of trastuzumab followed by 2 mg/kg weekly for up to 840 days. The model adequately predicted observed trastuzumab concentrations. Model stability and performance were verified using bootstrap simulations. Percentiles, mean, and standard deviation of observed levels were compared with their distributions from 100 replicates of datasets simulated under the model. Results: A two-compartment linear pharmacokinetic model best described the data and accounted for the long-term accumulation observed following weekly administration of trastuzumab. Population estimates from the base model for clearance (CL) and volume of distribution of the central compartment (V₁) of trastuzumab were 0.225 L/day, and 2.95 L, respectively. Estimated terminal halflife (t_1/2) based on the population estimate was 28.5 days. Interpatient variabilities in clearance and volume were 43 and 29%, respectively. The number of metastatic sites, plasma level of extracellular domain of the HER2 receptor, and patient weight were significant baseline covariates for clearance, volume, or both (P<0.005). However, these covariate effects on trastuzumab exposure were modest and not clinically important in comparison with the large inter-patient variability of CL. Concomitant chemotherapy (anthracycline plus cyclophosphamide, or paclitaxel) did not appear to influence clearance. Conclusion: This population pharmacokinetic model can predict trastuzumab exposure in the long-term treatment of patients with metastatic breast cancer and provide comparison of alternative dosage regimens via simulation.     

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.      

PD-1/PD-L1抑制剂联合曲妥珠单抗在HER2阳性乳腺癌中的研究进展

乳腺癌中有20%~30%的患者表达HER2基因,HER2阳性乳腺癌预后较差,易发生复发和转移。但HER2的表达为乳腺癌治疗提供了新方向。曲妥珠单抗是抗HER2治疗的经典基础药物,然而其原发继发耐药问题引起了大家的注意,研究发现其不敏感及耐药机制的发生可能与肿瘤细胞表面PD-L1上调相关。因此大量关于PD-1/PD-L1抑制剂联合曲妥珠单抗的研究展开意在提高其敏感度,改善其耐药问题。本文就PD-1/PD-L1抑制剂在HER2阳性乳腺癌的临床前及临床研究作一综述。     

Trastuzumab and breast cancer: developments and current status

The emergence of trastuzumab has drastically changed therapy for breast cancer. Trastuzumab (Herceptin; Genentech) is a recombinant humanized monoclonal antibody that targets an epitope in the extracellular domain of the human epidermal growth factor receptor 2 (HER2) protein. HER2 is a member of a family of four transmembrane receptor tyrosine kinases that regulate cell growth, survival, and differentiation via multiple signal transduction pathways. Overexpression of HER2 or amplification of the HER2 gene occurs in 20%–30% of human breast cancers. Preclinical models have demonstrated that this antibody has significant antitumor activity as a single agent, and it also has a synergy with certain chemotherapeutic drugs. Phase II and III clinical trials performed in women with metastatic breast cancers that overexpress HER2 have shown trastuzumab to have clinical activity when used as monotherapy, while also improving survival when used as a first-line therapy in combination with chemotherapy. At present, clinical investigations are focusing attention on the efficacy of trastuzumab in both the adjuvant and neoadjuvant setting, as well as in the metastatic setting. In this review, we describe the developments and current status of trastuzumab-based treatment for breast cancer.     

Dual HER2 Targeted Therapy With Pyrotinib and Trastuzumab in Refractory HER2 Positive Metastatic Colorectal Cancer: A Result From HER2-FUSCC-G Study

BackgroundDual-HER2 targeted therapy has led to a promising antitumor effect in HER2 positive cancers including gastrointestinal cancer. The present data focus on patients with HER2 positive colorectal cancer who received pyrotinib and trastuzumab after failure to standard second-line treatment.MethodsPatients diagnosed of HER2 positive refractory or metastatic colorectal cancer were enrolled to receive trastuzumab in combination with pyrotinib as third-line and beyond therapy. Trastuzumab was given as a loading dose at 8 mg/kg followed by 6mg/kg once every 3 weeks, and oral pyrotinib as 400 mg per day until progression. ORR was set as the primary endpoint. PFS and OS were set as a secondary endpoints. This trial is registered with Clinical Trial.gov, NCT04960943, and is ongoing.ResultsBetween February 2020 to December 2021, 16 patients including 14 with RAS wild-type status were enrolled in this cohort. ORR was 50.0% in the overall population, and 57.1% in RAS wild-type patients. At a median follow-up of 11.2 months, median PFS and OS were 7.53 and 16.8 months, respectively. The RAS/BRAF wild-type patients had prolonged survival (PFS: 7.53 vs. 1.63 months, P = .02; OS: NR vs.4.13 months, P = .001) compared with RAS/BRAF mutant patients. The most common treatment-emergent adverse event (TEAE) reported is diarrhea. Five (31.3%) patients reported grade 3 TEAEs, and no death was reported.ConclusionsTrastuzumab in combination with pyrotinib demonstrated encouraging antitumor activity that translated to prolonged survival benefit in HER2 positive refractory or mCRC patients who are RAS wild-type with acceptable tolerance.     

Evolution of anti-HER2 therapies for cancer treatment

The development of HER2-directed monoclonal antibodies and tyrosine kinase inhibitors have provided benefits to cancer patients, as well as produced many insights into the biology of the ErbB receptor family. Current therapies based on ErbB family members have resulted in improved overall survival with associated improvements in quality of life for the cancer patients that respond to treatment. Compared to monotherapy using either two antibodies to block the HER2 receptor blockade or combinatorial approaches with HER2 antibodies and standard therapies has provided additional benefits. Despite the therapeutic success of existing HER2 therapies, personalising treatment and overcoming resistance to these therapies remains a significant challenge. The heterogeneous intra-tumoural HER2 expression and lack of fully predictive and prognostic biomarkers remain significant barriers to improving the use of HER2 antibodies. Imaging modalities using radiolabelled pertuzumab and trastuzumab allow quantitative assessment of intra-tumoural HER2 expression, HER2 antibody saturation and the success of different drug delivery systems to be assessed. Molecular imaging with HER2 antibodies has the potential to be a non-invasive, predictive and prognostic technique capable of influencing therapeutic decisions, predicting response and failure of treatments as well as providing insights into receptor recycling and signalling. Similarly, conjugating HER2 antibodies with novel toxic payloads or combining HER2 antibodies with cellular immunotherapy provide exciting new opportunities for the management of tumours overexpressing HER2. Future research will lead to higher therapeutic responses, lower toxicities and providing insight into the mechanisms of resistance to HER2-targeted treatments.     

Trastuzumab for HER2+ metastatic breast cancer in clinical practice: Cardiotoxicity and overall survival

The evidence on efficacy and safety of trastuzumab in metastatic breast cancers (MBC) mainly derives from randomized clinical trials. We assessed short- and long-term overall survival (OS) and cardiotoxicity in a large cohort of women with MBC treated with trastuzumab in clinical settings.Using healthcare administrative data of Lombardy (10 millions inhabitants), we identified a cohort of women receiving trastuzumab for MBC between 2006 and 2009. The cumulative risk of severe cardiac events and the OS from the first trastuzumab administration were estimated using the Kaplan–Meier method. Their predictors were assessed using Cox regression models.We found 681 trastuzumab MBC users. Thirty two (4.7%) women experienced severe cardiac adverse events. The cumulative risk increased sharply, reaching a value of 2.4% and 4.3% during the first and second year; thereafter it increased of about 1% per year. Age was a strong predictor of cardiotoxicity. The OS was 81.8%, 64.0%, 50.2%, 41.1% and 37.2% at 1, 2, 3, 4 and 5 years, respectively. Independent predictors of worse OS were: age, brain liver or lung metastasis compared to other metastasis, use of taxanes and other chemotherapies, a cardiac adverse event after trastuzumab use, and a higher time between metastasis and BC diagnoses.The incidence of cardiotoxicity among women treated with trastuzumab for HER2-positive MBC appeared higher than that reported in RCTs, particularly in elder patients. In spite of this, median survival, was, if anything, better.     

In vitro effects of Trastuzumab Emtansine (T-DM1) and concurrent irradiation on HER2-positive breast cancer cells

BackgroundTo determine the effects of concurrent irradiation and T-DM1 on HER2-positive breast cancer cell lines.MethodsFive human breast cancer cell lines (in vitro study) presenting various levels of HER2 expression were used to determine the potential therapeutic effect of T-DM1 combined with radiation. The toxicity of T-DM1 was assessed using viability assay and cell cycle analysis was performed by flow cytometry after BrdU incorporation. HER2 cells were irradiated at different dose levels after exposure to T-DM1. Survival curves were determined by cell survival assays (after 5 population doubling times).ResultsThe results revealed that T-DM1 induced significant lethality due to the intracellular action of DM1 on the cell cycle with significant G2/M phase blocking. Even after a short time incubation, the potency of T-DM1 was maintained and even enhanced over time, with a higher rate of cell death. After irradiation alone, the D₁₀ (dose required to achieve 10% cell survival) was significantly higher for high HER2-expressing cell lines than for low HER2-expressing cells, with a linearly increasing relationship. In combination with irradiation, using conditions that allow cell survival, T-DM1 does not induce a radiosensitivity.ConclusionsAlthough there is a linear correlation between intrinsic HER2 expression and radioresistance, the results indicated that T-DM1 is not a radiation-sensitizer under the experimental conditions of this study that allowed cell survival. However, further investigations are needed, in particular in vivo studies before reaching a final conclusion.     

Targeting HER 1 and 2 in breast cancer with lapatinib

Numerous clinical trials support the biological relevance of the HER2 oncoprotein in breast cancer. In spite of improved outcomes, overexpression of the receptor is associated with increased risks of disease relapse, even in patients with early, and potentially curable, disease. Until recently, development of resistance to trastuzumab left patients with no therapeutic option other than specifically targeted HER2. This paper provides an in-depth review of lapatinib, a dual HER kinase inhibitor, as well as some insight into three HER family members, in breast cancer.     

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.

Poly (ADP-ribose) polymerase inhibition enhances trastuzumab antitumour activity in HER2 overexpressing breast cancer

AimPoly (ADP-ribose) polymerase (PARP) inhibitors have shown promising results in Breast Cancer (BRCA) deficient breast cancer, but not in molecularly unselected patient populations. Two lines of research in this field are needed: the identification of novel subsets of patients that could potentially benefit from PARP inhibitors and the discovery of suitable targeted therapies for combination strategies.MethodsWe tested PARP inhibition, alone or combined with the anti-HER2 antibody trastuzumab on HER2+ breast cancer. We used two PARP inhibitors in clinical development, olaparib and rucaparib, as well as genetic downmodulation of PARP-1 for in vitro studies. DNA damage was studied by the formation of γH2AX foci and comet assay. Finally, the in vivo anti-tumour effect of olaparib and trastuzumab was examined in nude mice subcutaneously implanted with BT474 cells.ResultsIn a panel of four HER2 overexpressing breast cancer cell lines, both olaparib and rucaparib significantly decreased cell growth and enhanced anti-tumour effects of trastuzumab. Cells exposed to olaparib and trastuzumab had greater DNA damage than cells exposed to each agent alone. Mechanistic exploratory assays showed that trastuzumab downmodulated the homologous recombination protein proliferating cell nuclear antigen (PCNA). Combination treatment in the BT474 xenograft model resulted in enhanced growth inhibition, reduced tumour cell proliferation, and increased DNA damage and apoptosis.ConclusionTaken together, our results show that PARP inhibition has antitumour effects and increases trastuzumab activity in HER2 overexpressing breast cancer. These findings make this novel combination a promising strategy for clinical development.     

Trastuzumab monotherapy versus combination therapy for treating recurrent breast cancer: time to progression and survival

Background HER2 expression is an important prognostic and predictive factor of treatment efficacy in breast cancer. Trastuzumab, in particular, is a key drug in the treatment of HER2-positive recurrent breast cancer. However, the difference in treatment efficacy between trastuzumab monotherapy and combination therapy with chemotherapy is unclear. In order to elucidate this point, both treatments were compared in terms of efficacy by metastatic site, time to progression (TTP), and survival. Patients and methods The subjects were 1,471 breast cancer patients who had been evaluated for HER2 expression between 1998 and March 2006; 74 of these had recurrent breast cancer that had been treated with trastuzumab. Of these 74 patients, 39 received trastuzumab alone and 45 trastuzumab in combination with chemotherapy. The items of investigation were clinical effect, TTP, survival, biological markers such as ER/PgR, proliferation (Ki67) or p53 overexpression, nuclear grade, performance status (PS), lymph node metastasis, and tumor size. Results The HER2-positive rate was 23.3%, and the degree of malignancy in these HER2-positive patients was high; postoperative disease-free survival (DFS) was low. However, this tendency was clear in patients with hormone-responsive breast cancer. In patients with hormone-non-responsive breast cancer, HER2 negativity had a significantly higher Ki67 value, and there was no difference in DFS between patients with HER2-positive and -negative tumors. Among the 74 patients with recurrent breast cancer, the response rate to trastuzumab was 64.9%; however, among patients who received the combination treatment, the response rate was 86%. In patients with liver metastasis, the effect of trastuzumab alone was low, but that of the combination treatment was significantly high. TTP was 5.7 months and 15.9 months with trastuzumab alone and the combination therapy, respectively. Furthermore, a significant difference was seen in post-treatment survival; however, there was no significant difference in survival after a recurrence. In the multivariate analysis on factors for TTP, PS, clinical effect, and combination treatment were significant. However, good PS and early treatment were the significant factors in post-treatment survival. Conclusions The effect of trastuzumab in patients with recurrent breast cancer who received the combination treatment was significantly high and TTP was long. However, this was not a significant factor in terms of overall survival. In particular, a good PS and early treatment were important in post-treatment survival. This article is based on a presentation delivered at Symposium 3, “Molecular target therapy: basics and clinical application,” held on 30 June 2007 at the 15th Annual Meeting of the Japanese Breast Cancer Society in Yokohama.     

A Roundtable Discussion of the Breast Cancer Therapy Expert Group (BCTEG): Clinical Developments and Practice Guidance on Human Epidermal Growth Factor Receptor 2 (HER2)-positive Breast Cancer

Expression of human epidermal growth factor receptor 2 (HER2) in breast cancer defines a subset of patients (∼15%-20%) who are candidates for anti-HER2 therapies, most notably, trastuzumab, pertuzumab, antibody drug conjugates (eg, T-DM1), and tyrosine kinase inhibitor (TKI) drugs (eg, lapatinib and neratinib), all of which have dramatically changed the prognosis for this aggressive subtype of breast cancer. A roundtable meeting of the Breast Cancer Therapy Expert Group (BCTEG) was convened in March 2018 in an effort to discuss and clarify, from the perspective of the practicing community oncologist, recent developments in the diagnosis and treatment of HER2-positive (HER2⁺) breast cancer. Members of the group selected 4 key topics for discussion prior to the meeting, including diagnosis of HER2⁺ disease, and its treatment in the neoadjuvant, adjuvant, and metastatic settings. Approved testing methods, such as immunohistochemistry and fluorescence in situ hybridization, are used to demonstrate overexpression and/or amplification of HER2 in breast tumors, and established clinical guidelines are used to appropriately define treatment plans for patients with HER2⁺ disease. The panel acknowledges a range of treatment options now available for treatment of HER2⁺ breast cancer in the neoadjuvant, adjuvant, and advanced/metastatic settings, although it is noted that many controversies remain, including the optimal sequence of therapies, the most appropriate treatment(s) for subsets of patients with HER2⁺ disease (eg, hormone receptor-negative or -positive/HER2⁺), and uncertainties surrounding the diagnosis and definition of HER2⁺ disease. The current report summarizes the discussion of the BCTEG panel on this topic.     

Long-term Clinical Outcome of Trastuzumab and Lapatinib for HER2-positive Metastatic Colorectal Cancer

BackgroundERBB2 amplification occurs in 5% of RAS wild-type metastatic colorectal cancer (mCRC) and it has been shown to be a target for treatment with 2 HER2-directed combinations of trastuzumab and lapatinib or trastuzumab and pertuzumab. We present long-term clinical results of trastuzumab and lapatinib (HERACLES-A trial) at 6.7 years (82 months) follow-up and focus on central nervous system (CNS) recurrences.Patients and MethodsPatients had histologically confirmed KRAS exon 2 (codons 12 and 13) wild-type and HER2-positive mCRC. HER2 positivity was assessed by immunohistochemistry and in situ hybridization HERACLES diagnostic criteria. Patients were treated with intravenous trastuzumab 4 mg/kg loading dose, then 2 mg/kg once per week, and oral lapatinib 1000 mg per day until disease progression or toxicity. Patients who presented with symptoms or signs of CNS disease received brain computed tomography scan or magnetic resonance imaging.ResultsA total of 35 patients received trastuzumab and lapatinib and 32 were evaluable for response. One patient (3%) achieved complete response (CR), 8 (25%) partial response, and 13 (41%) stable disease. Therefore, response rate was 28%. Median progression-free survival was 4.7 months (95% confidence interval [CI] 3.7–6.1). Median overall survival was 10.0 months (95% CI 7.9–15.8). One patient achieved sustained CR still maintained at 7 years of follow-up. Progression in the central nervous system (CNS) occurred in 6 (19%) of 32 patients.ConclusionsLong-term (6.7 years) follow-up analysis of HERACLES-A supports using of trastuzumab and lapatinib as treatment reference for KRAS wild-type, chemorefractory HER2-positive mCRC. In this subset of patients, prolongation of survival is accompanied by CNS recurrences that will require diagnostic and therapeutic attention in future studies.Clinicaltrials. Gov identifier: NCT 03225937.