Neratinib overcomes trastuzumab resistance in HER2 amplified breast cancer

Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab.     

Pre- and Postoperative Neratinib for HER2-Positive Breast Cancer Brain Metastases: Translational Breast Cancer Research Consortium 022

PurposeThis pilot study was performed to test our ability to administer neratinib monotherapy before clinically recommended craniotomy in patients with HER2-positive metastatic breast cancer to the central nervous system, to examine neratinib’s central nervous system penetration at craniotomy, and to examine postoperative neratinib maintenance.Patients and MethodsPatients with HER2-positive brain metastases undergoing clinically indicated cranial resection of a parenchymal tumor received neratinib 240 mg orally once a day for 7 to 21 days preoperatively, and resumed therapy postoperatively in 28-day cycles. Exploratory evaluations of time to disease progression, survival, and correlative tissue, cerebrospinal fluid (CSF), and blood-based analyses examining neratinib concentrations were planned. The study was registered at ClinicalTrials.gov under number NCT01494662.ResultsWe enrolled 5 patients between May 22, 2013, and October 18, 2016. As of March 1, 2019, patients had remained on the study protocol for 1 to 75+ postoperative cycles pf therapy. Two patients had grade 3 diarrhea. Evaluation of the CSF showed low concentrations of neratinib; nonetheless, 2 patients continued to receive therapy without disease progression for at least 13 cycles, with one on-study treatment lasting for nearly 6 years. Neratinib distribution in surgical tissue was variable for 1 patient, while specimens from 2 others did not produce conclusive results as a result of limited available samples.ConclusionNeratinib resulted in expected rates of diarrhea in this small cohort, with 2 of 5 patients receiving the study treatment for durable periods. Although logistically challenging, we were able to test a limited number of CSF- and parenchymal-based neratinib concentrations. Our findings from resected tumor tissue in one patient revealed heterogeneity in drug distribution and tumor histopathology.     

Safety and efficacy of neratinib (HKI-272) plus vinorelbine in the treatment of patients with ErbB2-positive metastatic breast cancer pretreated with anti-HER2 therapy

BackgroundNeratinib (HKI-272) is a potent irreversible pan-ErbB tyrosine kinase inhibitor with clinical activity in patients with ErbB2/HER2-positive breast cancer.Patients and methodsPhase I of this open-label, phase I/II study investigated the maximum tolerated dose (MTD) of oral neratinib (160 or 240 mg/day) plus vinorelbine (25 mg/m²; days 1 and 8 of each 21-day cycle) in patients with solid tumors. Phase II assessed the safety, clinical activity, and pharmacokinetics of the combination in patients with HER2-positive metastatic breast cancer; the primary efficacy end point was objective response (OR).ResultsIn phase I (n = 12), neratinib (240 mg) plus vinorelbine (25 mg/m²) was established as the MTD. In phase II, 79 patients with HER2-positive metastatic breast cancer were treated at the MTD. The most common treatment-related adverse events were diarrhea (96%), neutropenia (54%), and nausea (50%). Three patients discontinued treatment due to diarrhea. No clinically important skin side-effects were observed. The OR rate in assessable phase II patients was 41% (no prior lapatinib) and 8% (prior lapatinib). There was no evidence of pharmacokinetic interaction between neratinib and vinorelbine.ConclusionNeratinib plus vinorelbine showed promising antitumor activity and no unexpected toxic effects in HER2-positive metastatic breast cancer patients.Trial registrationClinicalTrials.gov #NCT00706030.     

Comparative analysis of drug response and gene profiling of HER2-targeted tyrosine kinase inhibitors

Background Human epidermal growth factor 2 (HER2/ERBB2) is frequently amplified/mutated in cancer. The tyrosine kinase inhibitors (TKIs) lapatinib, neratinib, and tucatinib are FDA-approved for the treatment of HER2-positive breast cancer. Direct comparisons of the preclinical efficacy of the TKIs have been limited to small-scale studies. Novel biomarkers are required to define beneficial patient populations.Methods In this study, the anti-proliferative effects of the three TKIs were directly compared using a 115 cancer cell line panel. Novel TKI response/resistance markers were identified through cross-analysis of drug response profiles with mutation, gene copy number and expression data.Results All three TKIs were effective against HER2-amplified breast cancer models; neratinib showing the most potent activity, followed by tucatinib then lapatinib. Neratinib displayed the greatest activity in HER2-mutant and EGFR-mutant cells. High expression of HER2, VTCN1, CDK12, and RAC1 correlated with response to all three TKIs. DNA damage repair genes were associated with TKI resistance. BRCA2 mutations were correlated with neratinib and tucatinib response, and high expression of ATM, BRCA2, and BRCA1 were associated with neratinib resistance.Conclusions Neratinib was the most effective HER2-targeted TKI against HER2-amplified, -mutant, and EGFR-mutant cell lines. This analysis revealed novel resistance mechanisms that may be exploited using combinatorial strategies.Subject terms: Tumour biomarkers, Targeted therapies     

Neratinib for the treatment of HER2-positive early stage breast cancer

Introduction: Despite the advances in the treatment of HER2-positive breast cancer, resistance to actual chemotherapeutic regimens eventually occurs. Neratinib, an orally available pan-inhibitor of the ERBB family, represents an interesting new option for early-stage HER2-positive breast cancer.

Areas covered: In this article, the development of neratinib, with a special focus on its potential value in the treatment of early-stage HER2-positive breast cancer, has been reviewed. For this purpose, a literature search was conducted, including preclinical studies, early-phase trials in advanced cancer with neratinib in monotherapy and in combination, and phase II and large phase III trials in the early setting. Management of neratinib-induced toxicity, future perspectives for the drug, and ongoing trials are also discussed in this review.

Expert commentary: Neratinib is emerging as a promising oral drug for the treatment of HER2-positive breast cancer. Although FDA and EMA approval is derived from the extended adjuvant treatment, this setting may not be the ideal scenario to obtain the beneficial effects of neratinib. Confirmatory data in the neoadjuvant setting and subgroup analysis from the ExTENET trial might bring some light into the best setting for neratinib therapy. Data from confirmatory trials in the metastatic setting are also required.     

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.     

Phase II study of neratinib in older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer

ObjectiveThe tolerability and efficacy of targeted therapy in older adults with cancer has not been adequately studied. Neratinib is a novel HER1, HER2, HER4 tyrosine kinase inhibitor that has recently been granted FDA approval for treatment of breast cancer. The major toxicity of neratinib is diarrhea, which affects up to 90% of patients. This phase II trial evaluates the safety and tolerability of neratinib in adults ≥60.MethodsPatients aged 60 or older with histologically proven metastatic breast cancer and HER2 amplification (defined by ASCO/CAP guideline) or HER2/HER3 activating mutation were enrolled to receive neratinib at 240 mg daily in 28-day cycles. The association between tolerability, defined as dose reduction and number of completed courses, and log₂ Cancer and Aging Research Group (CARG) toxicity risk score was assessed using a Student's t-test and linear regression, respectively. Response rate, progression free survival, and overall survival were also evaluated.Results25 patients were enrolled with median age of 66 (range 60–79). Seventy-six percent of patients were white, 16% Asian, and 8% African-American. Seventy-six percent were patients with hormone receptor (HR) positive metastatic breast cancer (MBC) and 24% were patients with HR negative MBC. Median number of prior lines of metastatic therapy were 3 (range 0–11). 20/25 (80%) had worst grade toxicities ≥2. A total of 9/25 (36%) had grade 3 toxicities including 5/20 (20%) diarrhea, 2/20 (8%) vomiting, and 2/20 (8%) abdominal pain. There were no grade 4 or 5 toxicities. A total of 9/25 (36%) had dose reduction, and 2/25 (8%) discontinued therapy due to toxicity. The association between dose reductions and CARG toxicity score reached borderline statistical significance suggesting a trend with participants with higher CARG toxicity risk scores being more likely to require a dose modification (p = 0.054). 1/25 (4%) had a partial response, 11/25 (44%) had stable disease, 12/25 (48%) had progression of disease, and 1/25 (4%) was not assessed. Median progression free survival (PFS) was 2.6 months (95% CI [2.56–5.26]), and median overall survival (OS) was 17.4 months (95% CI [10.3, NA]).ConclusionsNeratinib was safe in this population of older adults with HER2 amplified or HER2/3 mutated metastatic breast cancer (BC). Higher CARG toxicity risk score may be associated with greater need for dose adjustments. Future studies are needed to confirm this finding.     

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).     

HER2阳性乳腺癌治疗的研究进展

人表皮生长因子受体2(HER2)阳性乳腺癌因其侵袭性高、预后差而一直备受关注。随着曲妥珠单抗的应用,早期HER2阳性乳腺癌患者的预后已得到显著改善,由于其仍存在耐药性和不良反应,在标准治疗中加入新的抗HER2药物又成为新的研究重点,这些药物包括帕妥珠单抗、抗体药物偶联物曲妥珠单抗-美坦新(T-DM1)和各种小分子抑制剂(拉帕替尼、来那替尼、吡咯替尼)。同时PD1及PD-L1抑制剂如帕博利珠单抗在HER2阳性乳腺癌中的研究也在进行中,并有部分基础研究和病例报道已经证实了其疗效和安全性。本文旨在对目前HER2阳性乳腺癌的治疗方案和支持HER2阳性乳腺癌治疗的最新证据进行综述。     

The role of adjuvant monoclonal antibody therapy for breast cancer: rationale and new studies

HER2 is a member of the epidermal growth factor receptor (EGFR) family of tyrosine kinases and is involved in the growth, invasion, metastasis, and prognosis of breast cancer. The rationale for prospective trials evaluating the role of anti-HER2 monoclonal antibody therapy for patients with high-risk HER2-positive resected breast cancer is based on several factors. These include 1) the relative and absolute poor prognosis of patients with node-positive, HER2-positive breast cancer; 2) the emerging data of potential importance concerning anthracyclines as a component of adjuvant therapy for patients with HER2-positive breast cancer; 3) the role of taxanes in the management of patients with HER2-positive metastatic breast cancer; and 4) the feasibility and efficacy of molecularly targeted anti-HER2 monoclonal antibody treatment alone or in combination with chemotherapy for patients with advanced breast cancer.     

YES1 activation induces acquired resistance to neratinib in HER2‐amplified breast and lung cancers

Molecular‐targeted therapies directed against human epidermal growth factor receptor 2 (HER2) are evolving for various cancers. Neratinib is an irreversible pan‐HER tyrosine kinase inhibitor and has been approved by the FDA as an effective drug for HER2‐positive breast cancer. However, acquired resistance of various cancers to molecular‐targeted drugs is an issue of clinical concern, and emergence of resistance to neratinib is also considered inevitable. In this study, we established various types of neratinib‐resistant cell lines from HER2‐amplified breast and lung cancer cell lines using several drug exposure conditions. We analyzed the mechanisms of emergence of the resistance in these cell lines and explored effective strategies to overcome the resistance. Our results revealed that amplification of YES1, which is a member of the SRC family, was amplified in two neratinib‐resistant breast cancer cell lines and one lung cancer cell line. Knockdown of YES1 by siRNA and pharmacological inhibition of YES1 by dasatinib restored the sensitivity of the YES1‐amplified cell lines to neratinib in vitro. Combined treatment with dasatinib and neratinib inhibited tumor growth in vivo. This combination also induced downregulation of signaling molecules such as HER2, AKT and MAPK. Our current results indicate that YES1 plays an important role in the emergence of resistance to HER2‐targeted drugs, and that dasatinib enables such acquired resistance to neratinib to be overcome.     

Combination neratinib (HKI-272) and paclitaxel therapy in patients with HER2-positive metastatic breast cancer

Introduction:

Neratinib is a potent irreversible pan-ErbB tyrosine kinase inhibitor that has demonstrated antitumour activity and an acceptable safety profile in patients with human epidermal growth factor receptor (HER)-2-positive breast cancer and other solid tumours.

Methods:

This was a phase I/II, open-label, two-part study. Part 1 was a dose-escalation study to determine the maximum tolerated dose (MTD) of neratinib plus paclitaxel in patients with solid tumours. Part 2 evaluated the safety, efficacy, and pharmacokinetics of the combination at the MTD in patients with HER2-positive breast cancer.

Results:

Eight patients were included in the dose-escalation study; no dose-limiting toxicities were observed, and an MTD of oral neratinib 240 mg once daily plus intravenous paclitaxel 80 mg m⁻² on days 1, 8, and 15 of each 28-day cycle was determined. A total of 102 patients with HER2-positive breast cancer were enrolled in part 2. The overall median treatment duration was 47.9 weeks (range: 0.1–147.3 weeks). Common treatment-emergent adverse events (all grades/grade ⩾3) included diarrhoea (92%/29% none grade 4), peripheral sensory neuropathy (51%/3%), neutropenia (50%/20%), alopecia (46%/0%), leukopenia (41%/18%), anaemia (37%/8%), and nausea (34%/1%). Three (3%) patients discontinued treatment due to an adverse event (mouth ulceration, left ventricular ejection fraction reduction, and acute renal failure). Among the 99 evaluable patients in part 2 of the study, the overall response rate (ORR) was 73% (95% confidence interval (CI): 62.9–81.2%), including 7 (7%) patients who achieved a complete response; an additional 9 (9%) patients achieved stable disease for at least 24 weeks. ORR was 71% among patients with 0/1 prior chemotherapy regimen for metastatic disease and no prior lapatinib, and 77% among those with 2/3 prior chemotherapy regimens for metastatic disease with prior lapatinib permitted. Kaplan–Meier median progression-free survival was 57.0 weeks (95% CI: 47.7–81.6 weeks). Pharmacokinetic analyses indicated no interaction between neratinib and paclitaxel.

Conclusion:

The combination of neratinib and paclitaxel was associated with higher toxicity than that of neratinib as a single agent, but was manageable with antidiarrhoeal agents and dose reductions in general. The combination therapy also demonstrated a high rate of response in patients with HER2-positive breast cancer. A phase III trial is ongoing to assess the benefit and risk of this combination in the first-line setting.     

Effects of neratinib on health-related quality of life in women with HER2-positive early-stage breast cancer: longitudinal analyses from the randomized phase III ExteNET trial

BackgroundWe report longitudinal health-related quality-of-life (HRQoL) data from the international, randomized, double-blind, placebo-controlled phase III ExteNET study, which demonstrated an invasive disease-free survival benefit of extended adjuvant therapy with neratinib over placebo in human epidermal growth factor receptor-2-positive early-stage breast cancer.Patients and methodsWomen (N  = 2840) with early-stage HER2-positive breast cancer who had completed trastuzumab-based adjuvant therapy were randomly assigned to neratinib 240  mg/day or placebo for 12  months. HRQoL was an exploratory end point. Patients completed the Functional Assessment of Cancer Therapy–Breast (FACT-B) and EuroQol 5-Dimensions (EQ-5D) questionnaires at baseline and months 1, 3, 6, 9, and 12. Changes from baseline were compared using analysis of covariance with no imputation for missing values. Sensitivity analyses used alternative methods. Changes in HRQoL scores were regarded as clinically meaningful if they exceeded previously reported important differences (IDs).ResultsOf the 2840 patients (intention-to-treat population), 2407 patients were evaluable for FACT-B (neratinib, N  = 1171; placebo, N  = 1236) and 2427 patients for EQ-5D (neratinib, N  = 1186; placebo, N  = 1241). Questionnaire completion rates exceeded 85%. Neratinib was associated with a decrease in global HRQoL scores at month 1 compared with placebo (adjusted mean differences: FACT-B total, –2.9 points; EQ-5D index, −0.02), after which between-group differences diminished at later time-points. Except for the FACT-B physical well-being (PWB) subscale at month 1; all between-group differences were less than reported IDs. The FACT-B breast cancer-specific subscale showed small improvements with neratinib at months 3–9, but all were less than IDs. Sensitivity analyses exploring missing data did not change the results.ConclusionsExtended adjuvant neratinib was associated with a transient, reversible decrease in HRQoL during the first month of treatment, possibly linked to treatment-related diarrhea. With the exception of the PWB subscale at month 1, all neratinib-related HRQoL changes did not reach clinically meaningful thresholds. ClinicalTrials.gov: NCT00878709.     

The Adjuvant Treatment of HER2-Positive Breast Cancer

OPINION STATEMENT: About 15-20% of patients with early stage breast cancer present with tumors that have overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) gene. Before 2005, these individuals had an increased risk of recurrence and death, but since then their outcomes have substantially improved with the adoption in most countries of adjuvant trastuzumab as a standard component of therapy for HER2-positive early-stage breast cancer. Consequently, access to high-quality and accurate HER2 testing methods is critical to accurately determine HER2 status, guide treatment decisions, and ultimately improve clinical outcomes. In 2012, the humanized monoclonal anti-HER antibody trastuzumab was the only approved HER2-targeted therapy in the adjuvant setting. Data from the first generation of trials combining it with various chemotherapy regimens showed significant improvements in disease-free and overall survival (DFS/OS). Based on results from five randomized clinical trials, a trastuzumab-containing regimen for up to 1?year is now considered standard for all patients with HER2-positive tumors larger than 1?cm in size who would have fulfilled eligibility to those studies, and this recommendation is sometimes extended to patients with stage I tumors greater than 0.5?cm (T1b). Second generation adjuvant studies with other HER2-targeted agents like lapatinib and pertuzumab are ongoing, and newer drugs like T-DM1 and neratinib are being actively tested in the metastatic setting.     

Optimizing HER2-Directed Therapy in Early-Stage Breast Cancer

Purpose of Review

HER2-positive early breast cancer has been revolutionized by the development of HER2-directed therapy, which has significantly reduced breast cancer recurrence risk and improved overall survival. Here, we review the available treatment options for this patient population and discuss how we might individualize therapy in the future to optimize the balance of efficacy and toxicity.

Recent Findings

The addition of pertuzumab to a trastuzumab-based adjuvant regimen improves pathologic complete response rates and invasive disease-free survival (DFS). Addition of neratinib for patients with high-risk disease also contributes to improved DFS.

Summary

Current data supports use of dual HER2-directed therapy in combination with chemotherapy, as well as extended HER2-directed therapy (beyond 1 year), in those with high-risk HER2-positive early breast cancer. Ongoing studies aim to identify biomarkers of response and resistance to standard approaches, as well as identify those who might benefit from a chemotherapy-free treatment paradigm.

     

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.     

Neratinib in Combination With Trastuzumab for the Treatment of Patients With Advanced HER2-positive Breast Cancer: A Phase I/II Study

Background

Despite the availability of several human epidermal growth factor receptor 2 (HER2)-directed treatments, many HER2-positive (HER2⁺) breast cancers eventually progress because of primary or acquired resistance.

曲妥珠单抗治疗HER2+乳腺癌的临床进展

临床研究显示曲妥珠单抗与化疗联合用于人表皮生长因子受体2(HER2)+转移性乳腺癌的治疗以及早期乳腺癌的新辅助和辅助治疗,能显著延长患者的生存时间.其与内分泌治疗联合治疗HER2+且雌激素受体阳性的转移性乳腺癌,疗效优于单纯内分泌治疗.曲妥珠单抗联合其他靶向治疗药物,能够逆转肿瘤对曲妥珠单抗的耐药.疾病进展后继续应用曲妥珠单抗仍可使患者生存受益.     

A phase II study of lapatinib monotherapy in chemotherapy-refractory HER2-positive and HER2-negative advanced or metastatic breast cancer

BackgroundThe efficacy and tolerability of the epidermal growth factor receptor/human epidermal growth factor receptor type 2 (HER2) tyrosine kinase inhibitor lapatinib in refractory metastatic breast cancer were assessed.Patients and methodsIn a phase II, open-label study, patients with previously treated HER2-positive (n = 140) or HER2-negative (n = 89) metastatic breast cancer received once-daily oral lapatinib 1500 mg/day.ResultsMost (76%) patients had received four or more lines of prior therapy. The response rate in the HER2-positive cohort was 4.3% by investigator assessment and 1.4% by independent assessment. Both assessments established that ∼6% of HER2-positive patients derived clinical benefit from lapatinib, being progression free for ≥6 months. No objective tumor responses occurred in the HER2-negative cohort. Independent review assessments of median time to progression and median progression-free survival were similar in the HER2-positive and HER2-negative cohorts (9.1 and 7.6 weeks, respectively). All responders exhibited HER2 overexpression (3+ by immunohistochemistry), and five of six responders were HER2 amplified by FISH. Lapatinib-related adverse events, including diarrhea (54%), rash (30%), and nausea (24%), were primarily mild to moderate in severity.ConclusionsLapatinib monotherapy had modest clinical activity in HER2-positive metastatic breast cancer that progressed on prior trastuzumab regimens. No apparent clinical activity was observed in chemotherapy-refractory, HER2-negative disease.