Trastuzumab plus vinorelbine or taxane chemotherapy for HER2-overexpressing metastatic breast cancer: the trastuzumab and vinorelbine or taxane study

Pyrotinib Combined with Vinorelbine in Patients with Previously Treated HER2-Positive Metastatic Breast Cancer: A Multicenter, Single-Arm, Prospective Study

PURPOSE

This study aims to evaluate the efficacy and safety of a new combination treatment of vinorelbine and pyrotinib in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) and provide higher level evidence for clinical practice.

MATERIALS AND METHODS

This was a prospective, single-arm, phase 2 trial conducted at three institutions in China. Patients with HER2-positive MBC, who had previously been treated with trastuzumab plus a taxane or trastuzumab plus pertuzumab combined with a chemotherapeutic agent, were enrolled between March 2020 and December 2021. All patients received pyrotinib 400 mg orally once daily plus vinorelbine 25 mg/m2 intravenously or 60-80 mg/m2 orally on day 1 and day 8 of 21-day cycle. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included the objective response rate (ORR), disease control rate (DCR), overall survival, and safety.

RESULTS

A total of 39 patients were enrolled. All patients had been pretreated with trastuzumab and 23.1% (n=9) of them had accepted trastuzumab plus pertuzumab. The median follow-up time was 16.3 months (95% confidence interval [CI], 5.3 to 27.2), and the median PFS was 6.4 months (95% CI, 4.0 to 8.8). The ORR was 43.6% (95% CI, 27.8% to 60.4%) and the DCR was 84.6% (95% CI, 69.5% to 94.1%). The median PFS of patients with versus without prior pertuzumab treatment was 4.6 and 8.3 months (p=0.017). The most common grade 3/4 adverse events were diarrhea (28.2%), neutrophil count decreased (15.4%), white blood cell count decreased (7.7%), vomiting (5.1%), and anemia (2.6%).

CONCLUSION

Pyrotinib plus vinorelbine showed promising efficacy and tolerable toxicity as second-line treatment in patients with HER2-positive MBC.

Long-Term Complete Response with Single-Agent Capecitabine in Her-2-neu-Positive Metastatic Breast Cancer-A Rare Case Report

The standard treatment approach for metastatic breast cancer with HR- and Her-2-neu + disease is trastuzumab with systemic therapy. But in patients having severe cardiac dysfunction, trastuzumab is avoided. Various combination regimens are available in that setting, but no study has shown better efficacy of capecitabine monotherapy in this setting. We hereby present a case report of using capecitabine monotherapy in first-line setting, and the patient had complete resolution of lung metastasis from the last 2 years. A 64-year-old postmenopausal lady with a known case of breast carcinoma in the left side diagnosed in the year 2016 with hormone receptor-positive, Her2-negative disease completed chemoradiation and on is aromatase inhibitor from the last 5 years. She complained of breathlessness and fatigue lasting for 1 month in July 2021. On evaluation, chest CT scan revealed multiple bilateral lung metastases along with 3×3 cm right-sided breast lump with no metastasis elsewhere in the body. Core needle biopsy of breast lump and CT-guided left lung nodule biopsy were performed which revealed infiltrating carcinoma with immunohistochemical markers showing tumor cells positive for Her-2-neu with hormone receptor-negative disease. PET-CT scan was done which revealed FDG avidity in bilateral lung fields and right breast lump with no disease elsewhere. Her echocardiography showed ejection fraction of 40% owing to which injection trastuzumab was deferred and the plan to start tablet capecitabine 1000 mg twice BD days 1-14 cycles every 21 days was made. She showed improvement in symptoms with PET-CT scan revealing resolution of lung metastasis from the last 2 years. Trastuzumab in combination with pertuzumab and taxane is the standard of care for metastatic breast carcinoma with hormone receptor-negative and Her2-positive disease. But in patients who are elderly, frail with severe cardiac dysfunction, trastuzumab-based regimen is contraindicated. No study demonstrated efficacy of capecitabine monotherapy in this subset of disease. More prospective studies are required to identify patients who can benefit from capecitabine monotherapy in first-line setting in this subset of disease. Also capecitabine usage has several advantages mainly low cost and availability in oral form, and patients can be followed up on OPD basis.

Adjuvant trastuzumab and vinorelbine for early-stage HER2+ breast cancer

Background

The single-arm phase II APT trial established trastuzumab and paclitaxel (TH) as the standard adjuvant regimen for small human epidermal growth factor receptor 2 (HER2+) tumors. However, paclitaxel causes alopecia and has high rates of neuropathy and hypersensitivity reactions. In patients with metastatic HER2+ breast cancer (BC), the combination of trastuzumab and vinorelbine (TV) is effective and well tolerated. There is a need for alternative non-anthracycline/taxane-based regimens for patients with HER2+ early-stage BC, especially for those with contraindications or who wish to avoid side effects of taxane-based regimens. Here we describe our institutional experience with adjuvant TV for patients with early-stage HER2+ BC.

Methods

Clinicopathological characteristics, treatment details, and outcomes of patients with localized HER2+ BC treated with adjuvant TV from 2007 to 2021 at a large academic medical institution were collected. Study endpoints included invasive disease-free survival (IDFS), overall survival (OS), and safety/tolerability. IDFS and OS were measured from start date of TV treatment to date of event/last follow-up and date of death/last follow-up, respectively.

Results

A total of 30 patients were treated with TV. All patients received trastuzumab at standard dosing and vinorelbine at a starting dose of 25 mg/m² either on days 1/8 or on days 1/8/21 (weekly) of a 21-day cycle with four planned cycles. Median age at diagnosis was 59 years (range: 36-81). 90.3% of patients had anatomic pathologic stage IA BC and 9.7% stage IIA BC. Of the 30 patients, 24 of them opted to pursue TV due to concerns related to alopecia, neuropathy, and other toxicities, and 6 switched from treatment with TH to TV due to toxicities. Eight patients experienced neutropenia with no cases of febrile neutropenia. No patients experienced alopecia or long-term neuropathy. With a median follow-up of 68 months (5.7 years), the 5-year IDFS rate was 90.9%, with one local and one distant recurrence. The 5-year OS was 100%.

Conclusions

Trastuzumab in combination with vinorelbine in the adjuvant, early-stage setting for low-risk HER2+ BC demonstrated clinical efficacy and appeared to be well tolerated. TV warrants further evaluation as an alternative regimen to TH for patients with early-stage HER2+ BC.

Systemic Treatment of Breast Cancer. 1st Central-Eastern European Professional Consensus Statement on Breast Cancer

This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified based on the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The professional guideline primarily reflects the resolutions and recommendations of the current ESMO, NCCN and ABC5, as well as that of the St. Gallen Consensus Conference statements. The recommendations cover classical prognostic factors and certain multigene tests, which play an important role in therapeutic decision-making. From a didactic point of view, the text first addresses early and then locally advanced breast cancer, followed by locoregionally recurrent and metastatic breast cancer. Within these, we discuss each group according to the available therapeutic options. At the end of the recommendations, we summarize the criteria for treatment in certain rare clinical situations.

Novel Therapies for the Treatment of HER2-Positive Advanced Breast Cancer: A Canadian Perspective

The advent of anti-HER2 targeted therapies has dramatically improved the outcome of HER2-positive breast cancer; however, resistance to treatment in the metastatic setting remains a challenge, highlighting the need for novel therapies. The arrival of new treatment options and clinical trials examining the efficacy of novel agents may improve outcomes in the metastatic setting, including in patients with brain metastases. In the first-line setting, we can potentially cure a selected number of patients treated with pertuzumab + trastuzumab + taxane. In the second-line setting, clinical trials show that trastuzumab deruxtecan (T-DXd) is a highly effective option, resulting in a shift from trastuzumab emtansine (T-DM1) as the previous standard of care. Moreover, we now have data for patients with brain metastases to show that tucatinib + trastuzumab + capecitabine can improve survival in this higher-risk group and be an effective regimen for all patients in the third-line setting. Finally, we have a number of effective anti-HER2 therapies that can be used in subsequent lines of therapy to improve patient outcomes. This review paper discusses the current treatment options and presents a practical treatment sequencing algorithm in the context of the Canadian landscape.

Response of Leptomeningeal Metastasis of Breast Cancer With a HER2/neu Activating Variant to Tucatinib: A Case Report

Metastatic breast cancer demonstrates HER2/neu amplification approximately 15% of the time. However, HER2 mutations, which often stimulate tumor growth, occur in only 3% to 5% of patients, and are seen more frequently in metastatic versus primary tumors. They are more frequent in lobular carcinoma, including triple-negative lobular cancer. Many of these variants are resistant to trastuzumab and lapatinib. However, neratinib can be efficacious, and recent data suggest that antibody-drug conjugates (ADCs) such as ado-trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan may also be helpful. Laboratory and clinical data raise the possibility that simultaneous treatment with ADCs plus neratinib may be even more efficacious. Tucatinib, which has demonstrated significant activity in the central nervous system, has also been shown in vitro to be active against a number of these HER2 variants. This report describes a patient with metastatic estrogen receptor-positive, HER2-nonamplified breast cancer with an activating HER2 mutation whose tumor became resistant to neratinib as well as capecitabine, but whose subsequent leptomeningeal disease had a dramatically successful response to tucatinib plus capecitabine. As the frequency of HER2 mutations increases during the evolution of metastatic breast cancer, it is important to obtain genomic evaluation on these tumors with either repeat tissue or liquid biopsy as they progress over time.

Anti-HER2 therapy in metastatic breast cancer: many choices and future directions

Metastatic HER2 + breast cancer is an expanding area of drug development and research, with three new drugs approved in 2020 alone. While first-line therapy is well-established for metastatic HER2 + breast cancer, the standard of care for second-line therapy will likely be changing soon based on the results of the DESTINY-Breast03 trial. In the third-line setting, many options are available. Considerations in choosing between regimens in the third-line include resistance to trastuzumab, the presence of brain metastases, and tolerability. High rates of resistance exist in this setting particularly due to expression of p95, a truncated form of HER2 that constitutively activates downstream signaling pathways. We suggest a tyrosine kinase inhibitor (TKI)-based regimen because of the activity of TKIs in brain metastases and in p95-expressing tumors. Attempts to overcome resistance to anti-HER2 therapies with PI3K inhibitors, mTOR inhibitors, and CDK 4/6 inhibitors are an active area of research. In the future, biomarkers are needed to help predict which therapies patients may benefit from the most. We review the many new drugs in development, including those with novel mechanisms of action.

Network pharmacology-based approach to understand the effect and mechanism of Danshen against anemia

ETHNOPHARMACOLOGICAL RELEVANCE

Danshen, the dried rhizome of Salvia miltiorrhiza Bge., is widely used to treat cardio-cerebrovascular diseases in China. However, its role in nourishing blood, which has been detailed in historical literature for thousands of years, is perpetually disputed in the academic field. Moreover, there is no systematic research on Danshen in treating anemia. This research aimed to investigate the effects and mechanisms of Danshen on anemia in a zebrafish model based on the results of a network pharmacology study.

MATERIALS AND METHODS

The network pharmacology study was based on the screening of chemical components and related targets from TCMSP and SwissADME database. The genes associated with anemia were obtained from DisgeNet database, and the genes with the intersection of Danshen target genes were screened out. The Cytoscape 3.7.2 software package was used to construct the "ingredient-target-pathway" network. The exploration of target interaction by String system and the enrichment analysis by Metascape system, was used to discover the possible anti-anemia action mechanism of Danshen. Then, a zebrafish anemia model was induced by vinorelbine followed by the administration of aqueous/ethanol extract of Danshen in contrast to SiWu Decoction (SWD), which is generally acknowledged as a positive drug for tonifying blood. Afterward, the red blood cell signal, cardiac output, and blood flow velocity were detected to evaluate their blood-enriching effects. Quantitative real-time polymerase chain reaction (qPCR) was used to analyze the mRNA levels of hematopoietic-related factors, which were predicted in network pharmacology.

RESULTS

Compounds and target screening hinted that 115 chemical targets from Danshen were related to anemia, KEGG pathway enrichment results suggested that the mechanism of Danshen in treating anemia was significantly related to the Jak-STAT signaling pathway. Pharmacodynamic results showed that aqueous extract of Danshen (DSAE) and ethanol extract of Danshen (DSEE) markedly enhanced the number of red blood cells, cardiac output, and blood flow velocity. Compared with DSAE, DSEE exerted anti-anemia effects at a lower dose; however, along with higher toxicity. PCR data demonstrated that DSAE and DSEE treatment both upregulated the mRNA expression of erythroid hematopoiesis-related factors in the Epo-JAK-STAT signaling pathway, such as Gata-1, Epo, EpoR, Jak2, STAT3, and STAT5. In general, DSAE exhibited higher activation of this signaling than DSEE.

CONCLUSIONS

These results indicated that DSAE and DSEE both possess blood-enriching functions related with their ability to promote Jak-STAT signaling. DSAE exerted lower toxicity and attenuated anemia over a wider dose range than DSEE, which suggests that DSAE may be more suitable for the treatment for anemia. These results presented experimental evidence for the clinical use of Danshen as an intervention for anemia, especially in chemotherapy-induced anemia.

Comparative review of pharmacological therapies in individuals with HER2-positive advanced breast cancer with focus on hormone receptor subgroups

Breast cancer is the fifth leading cause of cancer-related deaths worldwide. The randomized controlled trials (RCTs) of targeted therapies in human epidermal receptor 2 (HER2)-positive advanced breast cancer (ABC) have provided an evidence base for regulatory and reimbursement agencies to appraise the use of cancer therapies in clinical practice. However, a subset of these patients harbor additional biomarkers, for example, a positive hormone receptor status that may be more amenable to therapy and improve overall survival (OS). This review seeks to explore the reporting of evidence for treatment effects by the hormone receptor status using the RCT evidence of targeted therapies for HER2-positive ABC patients. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed to identify published RCTs. Extracted data were synthesized using network meta-analysis to obtain the relative effects of HER2-positive-targeted therapies. We identified a gap in the reporting of the effectiveness of therapies by the hormone receptor status as only 15 out of 42 identified RCTs reported hormone receptor subgroup analyses; the majority of which reported progression-free survival but not OS or the overall response rate. In conclusion, we recommend that future trials in ABC should report the effect of cancer therapies in hormone receptor subgroups for all outcomes.

Modelling hypersensitivity to trastuzumab defines biomarkers of response in HER2 positive breast cancer

BACKGROUND

Trastuzumab-based therapies are the therapeutic option for HER2 positive (HER2+) breast cancer. HER2 amplification is the only biomarker validated for trastuzumab-based therapies. However, a proportion of tumors become refractory during treatment course. For this reason, the finding of new biomarkers beyond HER2 overexpression to identify patients who would benefit most from trastuzumab regimens is of outstanding importance.

METHODS

Models of trastuzumab-resistant or hypersensitive cells were generated by exposure to trastuzumab. Cell surface, total HER2, and analyses of proteins involved in cell cycle or apoptosis were analyzed by western blotting. Cell proliferation was analyzed by cell counting, cell cycle and apoptosis was evaluated by FACS. Transcriptomic characterization of the cellular models was performed using bioinformatic online tools, and clinico-genomic analyses were performed using the PAMELA clinical trial data.

RESULTS

Besides differing in sensitivities to trastuzumab, the different cellular models also showed distinct response to other anti-HER2 drugs (lapatinib, neratinib, pertuzumab and T-DM1) used in the clinic. That differential effect was not due to changes in cell surface, total or activated HER2. Trastuzumab caused important induction of cell death in hypersensitive cells but not in parental or resistant cells. Transcriptomic analyses of these cellular models together with querying of online databases allowed the identification of individual genes and gene signatures that predicted prognosis and trastuzumab response in HER2+ breast cancer patients.

CONCLUSION

The identification of trastuzumab response biomarkers may be used to select patients particularly sensitive to facilitate the use of trastuzumab-based therapies and refine follow-up guidelines in patients with HER2+ tumors.

Neu Perspectives, Therapies, and Challenges for Metastatic HER2-Positive Breast Cancer

Even though gene amplification or protein overexpression occurs in approximately one-fifth of all breast cancers, the discovery of HER2 has, nevertheless, had profound implications for the disease. Indeed, the characterization of the receptor resulted in a number of significant advances. Structurally, unique features provided avenues for the development of numerous compounds with target-specificity; molecularly, biological constructs revealed a highly complex, internal signal transduction pathway with regulatory effects on tumor proliferation, survival, and perhaps, even resistance; and clinically, disease outcomes manifested its predictive and prognostic value. Yet despite the receptor’s utility, the beneficial effects are diminished by tumor recurrence after neo- or adjuvant therapy as well as losses resulting from the inability to cure patients with metastatic disease. What these observations suggest is that while tumor response may be partially linked to uncoupling cell surface message reception and nuclear gene expression, as well as recruitment of the innate immune system, disease progression and/or resistance may involve a reprogrammable signaling mainframe that elicits alternative growth and survival signals. This review attempts to meld current perceptions related to HER2-positive metastatic breast cancer with particular attention to current biological insights and therapeutic challenges.

The Efficacy of Pyrotinib as a Third- or Higher-Line Treatment in HER2-Positive Metastatic Breast Cancer Patients Exposed to Lapatinib Compared to Lapatinib-Naive Patients: A Real-World Study

Background: Pyrotinib is a novel irreversible pan-ErbB receptor tyrosine kinase inhibitor. Evidence of the efficacy of pyrotinib-based treatments for HER2-positive metastatic breast cancer (MBC) in patients exposed to lapatinib is limited.

Methods: Ninety-four patients who received pyrotinib as a third- or higher-line treatment for HER2-positive MBC were included in this retrospective study. The primary and secondary endpoints were overall survival (OS) and progression‐free survival (PFS). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were implemented to balance important patient characteristics between groups.

Results: Thirty (31.9%) patients were pretreated with lapatinib and subsequently received pyrotinib as an anti-HER2 treatment, and 64 (68.1%) patients did not receive this treatment. The OS and PFS indicated a beneficial trend in lapatinib-naive group compared to lapatinib-treated group in either the original cohort (PFS: 9.02 vs 6.36 months, p = 0.05; OS: 20.73 vs 14.35 months, p = 0.08) or the PSM (PFS: 9.02 vs 6.08 months, p = 0.07; OS: 19.07 vs 18.00 months, p = 0.61) or IPTW (PFS: 9.90 vs 6.17 months, p = 0.05; OS: 19.53 vs 15.10 months, p = 0.08) cohorts. Subgroup analyses demonstrated lapatinib treatment-related differences in PFS in the premenopausal subgroup and the no prior trastuzumab treatment subgroup, but no significant differences were observed in OS.

Conclusion: Pyrotinib-based therapy demonstrated promising effects in HER2-positive MBC patients in a real-world study, especially in lapatinib-naive patients, and also some activity in lapatinib-treated patients.

Efficacy and Safety of Anti-HER2 Agents in Combination With Chemotherapy for Metastatic HER2-Positive Breast Cancer Patient: A Network Meta-Analysis

Background

The presence of anti-HER2 agents, such as trastuzumab, pertuzumab, and trastuzumab emtansine (T-DM1), significantly improved the prognosis of metastatic HER2-positive (HER2+) breast cancers (BC). However, drug resistance and disease progression are still common. In order to further improve the treatment efficacy, new clinical trials about anti-HER2 agents in combination with chemotherapy are growing rapidly. We conducted the network meta-analysis to synthesize evidences of clinical trials to identify the best therapy for metastatic HER2+ BC.

Methods

A systematic search of randomized controlled trials regarding anti-HER2 agents in combination with chemotherapy for advanced or metastatic breast cancers up to May 2020 was conducted in Embase, PubMed, and the Cochrane Library. The primary outcome was progression-free survival (PFS). The secondary outcomes were overall survival (OS), objective response rate (ORR), and safety. Bayesian network meta-analysis was conducted to synthesize the results and rank the therapies.

Results

Twenty-six studies, including 16 studies for first-line treatments and 10 studies for second- or later-line treatments were included in the network meta-analysis. For first-line studies, the THP (taxanes + trastuzumab + pertuzumab) regimen exhibited the highest probability to be the optimal treatment in all efficacy outcomes and moderate safety. For second- or later-line studies, the T-DM1 and XHTuC (capecitabine + trastuzumab + tucatinib) regimens ranked top two in all efficacy outcomes according to the surface under the cumulative ranking (SUCRA) results. T-DM1 ranked first in PFS and OS whereas XHTuC ranked first in ORR. The safety outcomes of T-DM1 and XHTuC were acceptable.

Conclusions

THP was still the optimal first-line treatment for metastatic HER2+ BC. T-DM1 and XHTuC were recommended for second-line treatments.

Systematic Review Registration

INPLASY.com, identifier (INPLASY202090086).

Targeting HER2 in Breast Cancer: Latest Developments on Treatment Sequencing and the Introduction of Biosimilars

Approximately 20% of all breast cancers overexpress the human epidermal growth factor receptor 2 (HER2). Targeting breast cancer through this vital oncogenic protein has been a major step towards improved patient outcomes. Today, several anti-HER2 agents are in clinical use including: the monoclonal antibodies trastuzumab and pertuzumab; the small molecule inhibitors lapatinib, neratinib, and tucatinib; and the antibody-drug conjugates ado-trastuzumab emtansine and trastuzumab deruxtecan, in some jurisdictions. In addition, several trastuzumab biosimilars have recently been granted regulatory approval in North America and the EU, and are enhancing patient access to HER2-directed therapy. The various agents differ greatly in their side-effect profiles and approved indications, from neoadjuvant and adjuvant use in early disease, to first- and later-line use in metastatic disease. This review discusses the current treatment recommendations for the use of anti-HER2 agents alone and in combination, examines the latest advances in HER2-targeted drugs and how they may be best applied in clinical practice, and provides guidance on optimal sequencing of the growing array of therapeutic options for HER2-positive breast cancer.

ER+ Breast Cancer Strongly Depends on MCL-1 and BCL-xL Anti-Apoptotic Proteins

Breast cancer is the most frequent type of cancer and the major cause of mortality in women. The rapid development of various therapeutic options has led to the improvement of treatment outcomes; nevertheless, one-third of estrogen receptor (ER)-positive patients relapse due to cancer cell acquired resistance. Here, we use dynamic BH3 profiling (DBP), a functional predictive assay that measures net changes in apoptotic priming, to find new effective treatments for ER+ breast cancer. We observed anti-apoptotic adaptations upon treatment that pointed to metronomic therapeutic combinations to enhance cytotoxicity and avoid resistance. Indeed, we found that the anti-apoptotic proteins BCL-xL and MCL-1 are crucial for ER+ breast cancer cells resistance to therapy, as they exert a dual inhibition of the pro-apoptotic protein BIM and compensate for each other. In addition, we identified the AKT inhibitor ipatasertib and two BH3 mimetics targeting these anti-apoptotic proteins, S63845 and A-1331852, as new potential therapies for this type of cancer. Therefore, we postulate the sequential inhibition of both proteins using BH3 mimetics as a new treatment option for refractory and relapsed ER+ breast cancer tumors.

Optimal Strategies for Successful Initiation of Neratinib in Patients with HER2-Positive Breast Cancer

Neratinib is an irreversible, pan-human epidermal growth factor inhibitor that has shown efficacy across human epidermal growth factor receptor 2 (HER2)-positive breast cancer settings. Neratinib is indicated for use as extended adjuvant therapy for HER2-positive early-stage breast cancer or, in combination with capecitabine, in the treatment of HER2-positive metastatic breast cancer. The primary tolerability concern with neratinib is diarrhea, and severe diarrhea early in treatment can lead to a substantial proportion of patients discontinuing neratinib, which may lead to reduced or nonexistent efficacy. In order to establish a set of treatment recommendations for use of neratinib, on May 12, 2020, an expert panel of oncologists and gastroenterologists met virtually to discuss the role of neratinib in the treatment of patients with HER2-positive breast cancer. The panel reviewed the current data on neratinib, including efficacy across settings and diarrhea management strategies. Based on these data and their clinical experience, the panelists developed a set of recommendations to guide selection of patients for neratinib, implement weekly dose escalation at initiation of therapy, and prophylactically manage diarrhea.

Sterile, abscess-like cerebral lesion during trastuzumab therapy after HER2 status switch in a triple negative breast cancer patient: a case report and literature review

Background

Breast cancer is a global health problem – it is the most common malignancy among women. Triple negative breast cancers (TNBC) account for 10–20% of female breast cancer. Most TNBC cases confer poor prognosis. Brain metastasis appears in more than 15% in the triple negative breast cancer population, which causes serious decrease in survival. Changes of immunophenotype are not uncommon in breast cancer, offering new therapeutic options in cases where targetable proteins or pathways are being identified.

Case presentation

After five lines of chemotherapy and 82 months following the first diagnosis, our patient with brain metastatic triple negative breast cancer had human epidermal growth factor receptor 2 (HER2) genetic heterogeneity in the metastatic tissue sample interpreted as HER2 status conversion. After the removal of the metastasis, we started first line therapy for metastatic HER2 positive cancer with trastuzumab and paclitaxel. After the first cycle of trastuzumab, on day 8, she had a seizure, and neurosurgical examination showed an abscess-like lesion. The punctate proved to be sterile by microbiological and pathological examination, so we continued cytostatic therapy without the anti-HER2 antibody. 3 months later, we could not identify the previous abscess-like lesion in the control computer tomography (CT) scan, and our patient had no neurological deficits.

Conclusion

We emphasize the importance of regular tissue confirmation of predictive markers in progressive tumorous disease even if our presented case is not unequivocally a “conversion case”. Tumor subtype is determined according to algorithms and definitions published in guidelines, nevertheless, use of different guidelines may lead to controversial interpretation in cases where HER2 genetic heterogeneity is present. Furthermore, we suggest that seronegative, aseptic intracranial fluid effusion after the removal of a brain metastasis may possibly be a side effect of trastuzumab.

The strategic combination of trastuzumab emtansine with oncolytic rhabdoviruses leads to therapeutic synergy

We have demonstrated that microtubule destabilizing agents (MDAs) can sensitize tumors to oncolytic vesicular stomatitis virus (VSVΔ51) in various preclinical models of cancer. The clinically approved T-DM1 (Kadcyla®) is an antibody-drug conjugate consisting of HER2-targeting trastuzumab linked to the potent MDA and maytansine derivative DM1. We reveal that combining T-DM1 with VSVΔ51 leads to increased viral spread and tumor killing in trastuzumab-binding, VSVΔ51-resistant cancer cells. In vivo, co-treatment of VSVΔ51 and T-DM1 increased overall survival in HER2-overexpressing, but trastuzumab-refractory, JIMT1 human breast cancer xenografts compared to monotherapies. Furthermore, viral spread in cultured HER2⁺ human ovarian cancer patient-derived ascites samples was enhanced by the combination of VSVΔ51 and T-DM1. Our data using the clinically approved Kadcyla® in combination with VSVΔ51 demonstrates proof of concept that targeted delivery of a viral-sensitizing molecule using an antibody-drug conjugate can enhance oncolytic virus activity and provides rationale for translation of this approach.

The Japanese Breast Cancer Society Clinical Practice Guidelines for systemic treatment of breast cancer, 2018 edition

Purpose

We present the English version of The Japanese Breast Cancer Society (JBCS) Clinical Practice Guidelines for systemic treatment of breast cancer, 2018 edition.

Methods

The JBCS formed a task force to update the JBCS Clinical Practice Guidelines, 2015 edition, according to Minds Handbook for Clinical Practice Guideline Development 2014. First, we set multiple outcomes for each clinical question (CQ). Next, quantitative or qualitative systematic review was conducted for each of the multiple outcomes, and the strength of recommendation for the CQ was taken into consideration during meetings, with the aim of finding a balance between benefit and harm. Finalized recommendations from each session were confirmed through discussion and voting at the recommendation decision meeting.

Results

The recommendations, the strength of recommendation and the strength of evidence were determined based on systemic literature reviews and the meta-analyses for each CQ.

Conclusion

The JBCS updated the Clinical Practice Guidelines for systemic treatment of breast cancer.

Electronic supplementary material

The online version of this article (10.1007/s12282-020-01085-0) contains supplementary material, which is available to authorized users.

Breast Cancer, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

Several new systemic therapy options have become available for patients with metastatic breast cancer, which have led to improvements in survival. In addition to patient and clinical factors, the treatment selection primarily depends on the tumor biology (hormone-receptor status and HER2-status). The NCCN Guidelines specific to the workup and treatment of patients with recurrent/stage IV breast cancer are discussed in this article.

Evaluating the clinical effectiveness and safety of various HER2-targeted regimens after prior taxane/trastuzumab in patients with previously treated, unresectable, or metastatic HER2-positive breast cancer: a systematic review and network meta-analysis

Purpose

In the absence of head-to-head trial data, network meta-analysis (NMA) was used to compare trastuzumab emtansine (T-DM1) with other approved treatments for previously treated patients with unresectable or metastatic HER2-positive breast cancer (BC).

Methods

Systematic reviews were conducted of published controlled trials of treatments for unresectable or metastatic HER2-positive BC with early relapse (≤ 6 months) following adjuvant therapy or progression after trastuzumab (Tras) + taxane published from January 1998 to January 2018. Random-effects NMA was conducted for overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and safety endpoints.

Results

The NMA included regimens from seven randomized controlled trials: T-DM1 and combinations of Tras, capecitabine (Cap), lapatinib (Lap), neratinib, or pertuzumab (Per; unapproved). OS results favored T-DM1 over approved comparators: hazard ratio (HR) (95% credible interval [95% CrI]) vs Cap 0.68 (0.39, 1.10), LapCap 0.76 (0.51, 1.07), TrasCap 0.78 (0.44, 1.19). PFS trends favored T-DM1 over all other treatments: HR (95% CrI) vs Cap 0.38 (0.19, 0.74), LapCap 0.65 (0.40, 1.10), TrasCap 0.62 (0.34, 1.18); ORR with T-DM1 was more favorable than with all approved treatments. In surface under cumulative ranking curve (SUCRA) analysis T-DM1 ranked highest for all efficacy outcomes. Discontinuation due to adverse events was less likely with T-DM1 than with all comparators except neratinib. In general, gastrointestinal side effects were less likely and elevated liver transaminases and thrombocytopenia more likely with T-DM1 than with comparators.

Conclusions

The efficacy and tolerability profiles of T-DM1 are generally favorable compared with other treatments for unresectable or metastatic HER2-positive BC.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05577-7) contains supplementary material, which is available to authorized users.

HER2-Targeted PET Imaging and Therapy of Hyaluronan-Masked HER2-Overexpressing Breast Cancer

Human epidermal growth factor receptor 2 (HER2) is a biomarker in breast cancer, and its overexpression is required to initiate therapies using HER2-targeted antibodies. Although trastuzumab is one of the most effective therapeutic antibodies in HER2-overexpressing breast cancer, a significant number of patients do not benefit from this therapy due to inherent or acquired resistance mechanisms. One reported mechanism of resistance is the steric hindering effect caused by the polymeric complex formed between hyaluronan and CD44, thus preventing trastuzumab from binding to HER2. Hyaluronan/CD44 contributes as an obstacle for trastuzumab to bind HER2, but it is also involved in HER2 internalization. In this study, we used zirconium-89 (⁸⁹Zr)-labeled trastuzumab immunoPET to investigate whether degradation of hyaluronan can resensitize HER2-overexpressing breast cancer cells to trastuzumab. Targeted degradation of endogenously produced hyaluronan and inhibition of its synthesis were achieved by treating trastuzumab-resistant JIMT1 breast cancer cells with hyaluronidase (HLX) and 4-methylumbelliferone (4MU). The 4MU/HLX treatment reduced HER2 internalization by depleting hyaluronan/CD44 and the caveolin-1 (CAV1) endocytic protein, resulting in enhanced membrane-bound ⁸⁹Zr-labeled trastuzumab. 4MU/HLX enhanced trastuzumab tumor uptake, as evidenced by increased tumor binding of the ⁸⁹Zr-labeled trastuzumab in JIMT1 tumor xenografts. In vitro mechanistic studies demonstrated a decrease in HER2-mediated oncogenic signaling upon cell treatment with 4MU/HLX. Importantly, 4MU/HLX enhanced trastuzumab efficacy in JIMT1 xenografts. These data showed the utility of ⁸⁹Zr-labeled trastuzumab as a PET imaging agent to monitor the affinity of the antibody to HER2 during CD44/hyaluronan-specific inhibition with the overall goal of improving trastuzumab therapy.

Targeted therapeutic options and future perspectives for HER2-positive breast cancer

Over the past 2 decades, there has been an extraordinary progress in the regimens developed for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine (T-DM1) are commonly recommended anti-HER2 target agents by the U.S. Food and Drug Administration. This review summarizes the most significant and updated research on clinical scenarios related to HER2-positive breast cancer management in order to revise the guidelines of everyday clinical practices. In this article, we present the data on anti-HER2 clinical research of neoadjuvant, adjuvant, and metastatic studies from the past 2 decades. We also highlight some of the promising strategies that should be critically considered. Lastly, this review lists some of the ongoing clinical trials, findings of which may soon be available.

What therapies are on the horizon for HER2 positive breast cancer?

Introduction: Despite dramatic improvements in survival achieved with currently available anti-HER2 agents, HER2-positive metastatic breast cancer remains an almost invariably deadly disease, with primary or acquired resistance to HER2-directed agents developing during treatment. Many efforts are focused on identifying new agents that may more effectively inhibit HER2 signaling and on possible combination strategies. Areas covered: This review summarizes the landscape of drugs under development for HER2-positive metastatic breast cancer, as antibody-drug conjugates, monoclonal anti-HER2 antibodies, bispecific antibodies, or novel tyrosine kinase inhibitors. Moreover, available data for possible combination of anti-HER2 drugs and different agents, as immunotherapy, PI3K/mTOR inhibitors, CDK4/6 inhibitors currently under evaluation are reviewed. These strategies may overcome mechanisms of resistance and further improve patient outcomes. Expert opinion: Identification of valuable predictive biomarkers is needed to better inform choice of treatment sequence for the individual patient and limit the financial toxicity of these agents.

The Use of Immunotherapy to Treat Metastatic Breast Cancer

This article reviews the principal attempts of immune-modulation or immune therapy in metastatic breast cancer. It considers their rationale and reports on results from the relevant key clinical trials. Immune-modulatory or immune-stimulating cytokines used alone or combined with conventional therapies is among the principal approaches of immune manipulation in breast cancer. As this issue has recently been reviewed by us, the aim of the current article is to discuss our updated and unpublished data on this topic. Overall survival in luminal (28 patients) and non-luminal (9 patients) molecular subtypes is 91 and 59 months respectively that is about two and half or three times longer than expected. Thereafter, we focus on monoclonal antibodies (mAb) based-therapies including novel strategies to overcome resistance to anti-HER2 mAb. The main vaccine platforms in different molecular subtypes and immune therapies in triple negative metastatic breast cancer (m-TNBC) are discussed in the last sections. Some phase III investigations have already changed the current clinical practice. In fact, pertuzumab plus trastuzumab and docetaxel is the recommended first line regimen in HER2 positive locally recurrent or metastatic breast cancer and bevacizumab plus paclitaxel or docetaxel is a reasonable option for m-TNBC. In some other observational or phase I/II studies on first-line trastuzumab plus chemotherapy and hormonal therapy and in that on HER2 peptide/protein vaccines promising although preliminary findings have been reported to be further validated. In the remaining studies, results were disappointing. In the future, finding new predictive biomarkers and exploring more suitable synergizing combinations, time and dose-dependent-scheduled sequences of currently and further investigated immunological approaches are main challenges.

A phase Ib study of entinostat plus lapatinib with or without trastuzumab in patients with HER2-positive metastatic breast cancer that progressed during trastuzumab treatment

BACKGROUND

Human epidermal growth factor 2 (HER2) is an effective therapeutic target in breast cancer; however, resistance to anti-HER2 agents such as trastuzumab and lapatinib develops. In a preclinical model, an HDAC inhibitor epigenetically reversed the resistance of cancer cells to trastuzumab and showed synergistic efficacy with lapatinib in inhibiting growth of trastuzumab-resistant HER2-positive (HER2+) breast cancer.

METHODS

A phase 1b, dose escalation study was performed to assess maximum tolerated dose, safety/toxicity, clinical efficacy and explored pharmacodynamic biomarkers of response to entinostat combined with lapatinib with or without trastuzumab.

RESULTS

The combination was safe. The MTD was lapatinib, 1000 mg daily; entinostat, 12 mg every other week; trastuzumab, 8 mg/kg followed by 6 mg/kg every 3 weeks. Adverse events included diarrhoea (89%), neutropenia (31%), and thrombocytopenia (23%). Neutropenia, thrombocytopenia and hypokalaemia were noted. Pharmacodynamic assessment did not yield conclusive results. Among 35 patients with evaluable response, PR was observed in 3 patients and CR in 3 patients, 1 maintained SD for over 6 months.

DISCUSSION

This study identified the MTD of the entinostat, lapatinib, and trastuzumab combination that provided acceptable tolerability and anti-tumour activity in heavily pre-treated patients with HER2+ metastatic breast cancer, supporting a confirmatory trial.

Lapatinib activity in metastatic human epidermal growth factor receptor 2-positive breast cancers that received prior therapy with trastuzumab, pertuzumab, and/or ado-trastuzumab emtansine (T-DM1)

PURPOSE

Lapatinib (L) is approved in combination with capecitabine or letrozole for patients with trastuzumab-resistant HER2-positive metastatic breast cancer (MBC). However, there is no efficacy data of L in patients who received prior pertuzumab (P) and ado-trastuzumab emtansine (T-DM1), now included as standard first- and second-line therapies, respectively. The goal of this study was to assess the efficacy of L in a contemporary patient population that received prior P and/or T-DM1.

METHODS

We identified patients with HER2-positive MBC who received L (n = 520) between 2003 and 2017 at MD Anderson Cancer Center and selected a target cohort who received L after prior P or T-DM1 (n = 43) with the remaining included in the comparison cohort (n = 477). We evaluated outcome measures including clinical benefit rate (CBR), best tumor response (BTR), duration on L, and time to progression (TTP). Survival analyses used Kaplan-Meier statistics.

RESULTS

CBR was 28% (95% CI 10-32) for the target cohort and 40% (95% CI 36-45) for the comparison cohort. The median duration on L was 5 months (95% CI 3.0-9.0) in the target cohort and 6.7 months (5.9-8.0) in the comparison cohort. In both cohorts, the median time to progression (TTP) and overall survival (OS) were longer in patients with de novo metastatic disease compared to patients with disease recurrence.

CONCLUSION

L-based therapy is an active therapeutic option and remains a viable option for HER2 + MBC after prior trastuzumab, P and/or T-DM1.

Monoclonal antibodies for the treatment of non-hematological tumors: a safety review

Introduction: The introduction of monoclonal antibodies (moAbs) into clinical practice revolutionized the treatment strategies in several solid tumors. These agents differ from cytotoxic chemotherapy for their mechanism of action and toxicity. By targeting specific antigens present on healthy cells and modulating immune system activity, these biological drugs are able to generate a wide spectrum of peculiar adverse events that can negatively impact on patients' quality of life. Areas covered: In this review, the main side effects associated with the use of moAbs have been described to show their incidence and current management strategies, which may drive clinicians in their daily practice. Expert opinion: The majority of these drugs represents an example of successful innovation, since they are able to induce a significant improvement of patients' survival and quality of life without any increase in related side effects as compared to standard cancer treatments. For this reason, they have become new milestones in personalized therapy for different non-hematological malignancies. With the increasing use of moAbs in treatment regimens, it is strongly recommended that clinicians are knowledgeable about the side effects associated with these agents, their management and monitoring, to optimize the clinical treatment of cancer patients.

A multicenter REtrospective observational study of first-line treatment with PERtuzumab, trastuzumab and taxanes for advanced HER2 positive breast cancer patients. RePer Study

We carried out a retrospective observational study of 264 HER2-positive advanced breast cancer (ABC) patients to explore the efficacy of first-line treatment with pertuzumab/trastuzumab/taxane in real-world setting. Survival data were analyzed by Kaplan Meier curves and log rank test. Median follow-up, length of pertuzumab/trastuzumab/taxane treatment and of pertuzumab, trastuzumab maintenance were 21, 4 and 15 months, respectively. The response rate was 77.3%, and the clinical benefit rate 93.6%. Median progression-free survival (mPFS) was 21 months, and median overall survival (mOS) was not reached. When comparing patients by trastuzumab-pretreatment, similar PFS were observed, although a longer OS was reached in trastuzumab-naïve patients (p = 0.02). Brain metastases at baseline and their development in course of therapy were associated with significantly shorter PFS (p = 0.0006) and shorter OS, although at a not fully statistically relevant extent (p = 0.06). The addition of maintenance endocrine therapy (ET) to pertuzumab/trastuzumab maintenance was associated with longer PFS (p = 0.0001), although no significant differences were detected in OS (p = 0.31). Results were confirmed by propensity score analysis (p = 0.003 and p = 0.46, respectively). In multivariate models, longer PFS was related to lower Performance Status (PS) (p = 0.07), metastatic stage at diagnosis (p = 0.006) and single metastatic site (p < 0.0001). An OS advantage was observed with lower PS (p < 0.0001), single metastatic site (p = 0.004), no prior exposure to trastuzumab (p = 0.004) and response to pertuzumab-based treatment (p = 0.003). Our results confirm that trastuzumab/pertuzumab/taxane is the standard of care as first-line treatment of patients with HER2-positive ABC even in the real-world setting. Moreover, the double-maintenance therapy (HER2 block and ET) is strongly recommended when feasible.

Patients who achieved long-term clinical complete response and subsequently terminated multidisciplinary and anti-HER2 therapy for metastatic breast cancer: A case series

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Breast cancers that are positive for human epidermal growth factor receptor 2 (HER2) are aggressive and typically associated with a poor prognosis.

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Novel anti-HER2 therapies have recently improved the outcomes in these cases.

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We report a case series in which women were treated for metastatic HER2-positive breast cancer using trastuzumab and various chemotherapies.

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These patients ultimately achieved clinical complete response, and subsequently terminated their systemic therapy after maintenance therapy.

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Our findings indicate that select patients may be suitable for treatment termination if they have achieved a prolonged period of complete response.

Background

Human epidermal growth factor receptor 2 (HER2) -positive breast cancers tend to be more aggressive and more likely to recur than HER2-negative breast cancers. However, novel anti-HER2 therapies have dramatically improved the prognosis of patients with HER2-positive breast cancer.

Case report

We review the cases of 4 women with metastatic breast cancer who achieved clinical complete response (cCR) and terminated their systemic therapy. Two patients had de novo metastatic disease and two patients experienced relapse after adjuvant therapy. All patients achieved cCR using multidisciplinary therapy, experienced prolonged complete remission, and subsequently terminated their systemic therapy without experiencing secondary recurrence.

Conclusion

There is no evidence that systemic therapy can be safely terminated after a specific time period, although adverse events (e.g., cardiotoxicity) and unnecessary treatment should be avoided. Thus, it is possible that select patients may be suitable for termination of systemic therapy after they have achieved a prolonged period of cCR.

Adherence to prescribing restrictions for HER2-positive metastatic breast cancer in Australia: A national population-based observational study (2001-2016)

BACKGROUND

Targeted cancer therapy is often complex, involving multiple agents and chemotherapeutic partners. In Australia, prescribing restrictions are put in place to reflect existing evidence of cost-effectiveness of these medicines. As therapeutic options continue to expand, these restrictions may not be perceived to align with best practice and it is not known if their use in the real-world clinic adheres to these restrictions. We examined the treatment of women receiving trastuzumab for HER2-positive metastatic breast cancer (HER2+MBC) to determine the extent to which treatment adhered to national prescribing restrictions.

PATIENTS AND METHODS

Our population-based, retrospective cohort study used dispensing records for every Australian woman initiating publicly-subsidised trastuzumab for HER2+MBC between 2001-2013, followed through 2016. We used group-based trajectory models (GBTMs) to cluster patients, first on their patterns of trastuzumab exposure, and then on their patterns of lapatinib and chemotherapy exposure. We described the characteristics of patients within each cluster, and examined their treatments and combinations of treatments to determine restriction adherence.

RESULTS

Of 5,052 patients initiating trastuzumab, 1,795 (36%) received at least one non-adherent HER2-targeted treatment. The most common non-adherent treatments were trastuzumab combinations involving vinorelbine (24% of non-adherent treatments); capecitabine (24%); and anthracyclines (10%). Non-adherent lapatinib use was observed in 4% of patients. GBTM identified three trastuzumab exposure clusters, each containing three further sub-clusters. The largest proportions of non-adherent treatments were in sub-clusters with longer trastuzumab exposure and more non-taxane chemotherapy. Patients in these sub-clusters were younger than those in sub-clusters with less non-adherent treatment.

CONCLUSIONS

Our study highlights that, even during the relatively simpler treatment era of our study period, a substantial amount of treatment did not adhere to prescribing restrictions. As more trials are conducted exploring pertuzumab and T-DM1 in combination with different chemotherapies and other HER2-targeted therapies, the regulation and funding of HER2-targeted treatment will become more challenging.

Low neutrophil-lymphocyte ratio correlates with extended survival in patients with metastatic breast cancer who achieved clinically complete response following multidisciplinary therapy: A retrospective study

The prognosis of patients with metastatic or recurrent breast cancer (MBC) is improving as novel treatments are developed. The present study compared the clinical characteristics of patients with MBC with or without a complete clinical response (cCR) and identified the survival-associated factors. This was a retrospective study, which included 171 patients treated for MBC between 2011 and 2017 at the Shiga Medical Center for Adults. Neutrophil to lymphocytes ratios (NLRs) were determined in blood samples. The median follow-up period following diagnosis of MBC was 44 months (range, 0-217 months). A total of 32 patients (18.7%) achieved a cCR. Compared with the non-cCR group, the cCR group had significantly fewer metastases or recurrences (P<0.001), significantly fewer visceral metastases (P<0.001), a significantly lower NLR (P<0.001) and were diagnosed with primary breast cancer at a significantly earlier stage (P=0.003). Prognosis was significantly improved in the cCR group compared with the non-cCR group (P<0.001) and a high NLR (≥19) independently predicted worse survival in a multivariate analysis (P=0.0218; hazard ratio, 1.75; 95% confidence interval, 1.09-2.85). In conclusion, the present study determined that achieving a cCR and having a low NLR are important for the long-term survival of patients with MBC.

Trastuzumab and Vinorelbine as Highly Effective and Safe Therapy for HER-2-Overexpressing Metastatic Breast Cancer. A Single Institution Experience

Aims and Background

Trastuzumab-based therapy has improved survival of women with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic breast cancer.

Study Design

From September 2002 to July 2006, 45 women with metastatic breast cancer HER2 3+, or 2+ and positive for HER2 gene amplification, were enrolled in the study and received a combination therapy with vinorelbine, 25 mg/m2 weeks 1 and 2, plus trastuzumab, 4 mg/kg loading dose and then 2 mg/kg weekly, in a three weeks cycle. Eligibility criteria included measurable disease and a baseline ejection fraction ≥50%. Forty-two percent of the patients were not pretreated, whereas 58% had received a previous chemotherapy regimen for metastatic disease, including anthracy-clines and/or taxanes (47%), and trastuzumab plus taxol (11%).

Results

We observed 14 (31%) complete responses and 21 (47%) partial responses, with an overall response rate of 78%. Stable disease >6 months was assessed for 5 (11%) patients with a clinical benefit of 89%. Five (11%) patients progressed. With a median follow-up of 11 months, median time to progression was 9 months and median duration of response was 7.6 months for complete remissions and 4 months for partial remissions. Median survival was 29 months.

Conclusions

In spite of a smaller dose intensity of vinorelbine than previously reported, the regimen evaluated was notably effective in terms of response rate, time to progression and survival, with very mild toxicity.

Therapeutic Antibodies in Cancer Therapy. Adv Exp Med Biol. 2016;917:95-120. [PMID: 27236554 DOI: 10.1007/978-3-319-32805-8_6]

The therapeutic arsenal in solid tumors comprises different anticancer strategies with diverse chemotherapeutic agents and a growing number of biological substances. Large clinical study-based chemotherapeutic protocols combined with biologicals have become an important component in (neo-) adjuvant therapy alongside surgery in solid cancers as well as radiation therapy in some instances. In recent years, monoclonal antibodies have entered the mainstream of cancer therapy. Their first use was as antagonists of oncogenic receptor tyrosine kinases, but today monoclonal antibodies have emerged as long-sought vehicles for the targeted delivery of potent chemotherapeutic agents and as powerful tools to manipulate anticancer immune responses. There is a growing number of FDA approved monoclonal antibodies and small molecules targeting specific types of cancer suggestive of the clinical relevance of this approach.Targeted cancer therapies , also referred to as personalized medicine, are being studied for use alone, in combination with other targeted therapies, and in combination with chemotherapy. The use of monoclonal antibodies in colorectal and gastric cancer for example have shown best outcome when combined with chemotherapy, even though single agent anti-EGFR antibodies seem to be active in particular setting of metastatic colorectal cancer patients. However, it is not well defined whether the addition of anti-VEGF - and anti-EGFR strategies to chemotherapy could improve outcome in those patients susceptible to colorectal cancer-related metastases resection. Among the most promising approaches to activating therapeutic antitumor immunity is the blockade of immune checkpoints, exemplified by the recently FDA-approved agent, Ipilimumab, an antibody that blocks the coinhibitory receptor CTLA-4. Capitalizing on the success of Ipilimumab, agents that target a second coinhibitory receptor, PD-1, or its ligand, PD-L1, are in clinical development. This section attempts to discuss recent progress of targeted agents and in tackling a more general target applicable to gastrointestinal cancer .

Targeting protein quality control pathways in breast cancer

The efficient production, folding, and secretion of proteins is critical for cancer cell survival. However, cancer cells thrive under stress conditions that damage proteins, so many cancer cells overexpress molecular chaperones that facilitate protein folding and target misfolded proteins for degradation via the ubiquitin-proteasome or autophagy pathway. Stress response pathway induction is also important for cancer cell survival. Indeed, validated targets for anti-cancer treatments include molecular chaperones, components of the unfolded protein response, the ubiquitin-proteasome system, and autophagy. We will focus on links between breast cancer and these processes, as well as the development of drug resistance, relapse, and treatment.

Does dual HER-2 blockade treatment increase the risk of severe toxicities of special interests in breast cancer patients: A meta-analysis of randomized controlled trials

Although dual HER-2 blockade treatment could offer greater clinical efficacy in breast cancer, the risk of severe toxicities of special interest related to this combined regimen in breast cancer remained unknown. We systematically searched public databases (MEDLINE, EMBASE, Cochrane library) to identify relevant studies that comparing anti-HER2 monotherapy (lapatinib or trastuzumab or pertuzumab) with dual HER-2 blockade treatment (pertuzumab plus trastuzumab or trastuzumab plus lapatinib) in breast cancer. A total of 11,941 breast cancer patients from 9 trials were included for analysis. Meta-analysis showed that dual HER2 blockade treatment significantly increased the risk of severe diarrhea (OR 2.52, p<0.001) and treatment discontinuation (OR 1.52, p=0.014), but not for severe rash (OR 1.06, p=0.81), liver toxicities (OR 1.16, p=0.28), CHF (OR 1.46, p=0.09), LVEF decline (OR 1.09, p=0.40) and FAEs (OR 0.97, p=0.91). Similar results were observed in sub-group analysis according to anti-HER2 regimens in terms of severe diarrhea and treatment discontinuation. Additionally, trastuzumab plus lapatinib significantly increased the risk of LVEF decline in comparison with lapatinib alone (OR 1.48, p=0.002). Our analysis indicated that dual anti-HER2 blockade treatment significantly increased the risk of developing severe diarrhea and treatment discontinuation in comparison with anti-HER2 monotherapy. These were no evidence of an increased risk of fatal adverse events with dual-HER2 blockade treatment.

Palliative systemic therapy and overall survival of 1,395 patients with advanced breast cancer - Results from the prospective German TMK cohort study

Data on treatment and outcome of advanced breast cancer in routine practice are rare, especially concerning recurrent disease, but important to complement the results from clinical trials and to improve the standard of care. We present data on choice of systemic first-line treatment, number of treatment lines, and survival of patients treated by medical oncologists in Germany. 1395 patients recruited by 124 sites at start of first-line therapy into the ongoing, prospective German clinical cohort study TMK (Tumour Registry Breast Cancer) between February 2007 and October 2015 were analysed. The median OS was 33.8 months (95% CI 30.2-40.2) for HR-positive/HER2-negative, 38.2 months (95% CI 31.3-43.0) for HER2-positive and 16.8 months (95% CI 11.5-22.0) for triple negative breast cancer. Patients with triple negative tumours more often died before start of a third-line therapy than patients with HR-positive or HER2-positive tumours (44% vs. 25%). Use of taxane-based chemotherapies has increased since 2007, with 65% of all first-line chemotherapy-treatments containing taxanes in 2013-15 (60% HR-positive/HER2-negative, 75% HER2-positive, 56% triple negative). 52% of the patients with HR-positive/HER2-negative tumours received first-line endocrine therapy in 2013-15; when restricted to patients with only non-visceral metastases this percentage increased to 63%. To our knowledge, this is the first cohort study showing systemic first-line therapy for all subtypes of advanced breast cancer. Overall survival in the TMK is comparable to that reported by clinical trials despite the inclusion of older and comorbid patients.

Targeting HER2 in Advanced Breast Cancer

Human epidermal growth factor receptor 2 (HER2) is a human oncogene that is amplified in approximately 20% of breast cancers, and portends a worse prognosis if not treated with anti-HER2 agents. The advent of targeted anti-HER2 therapies has dramatically improved disease control and survival in patients with metastatic HER2-positive breast cancer, and is now considered standard of care in the first-line setting and beyond. This review summarizes the currently available data on targeted anti-HER2 therapies from completed randomized phase III clinical trials, and briefly discusses emerging advances that will address unmet needs in metastatic HER2-positive breast cancer.

Safety and efficacy of vinorelbine in combination with pertuzumab and trastuzumab for first-line treatment of patients with HER2-positive locally advanced or metastatic breast cancer: VELVET Cohort 1 final results

BACKGROUND

Pertuzumab, trastuzumab, and docetaxel is standard of care for first-line treatment of HER2-positive metastatic breast cancer (MBC). However, alternative chemotherapy partners are required to align with patient/physician preferences and to increase treatment flexibility. We report VELVET Cohort 1 results in which the efficacy and safety of pertuzumab and trastuzumab, administered sequentially in separate infusions, followed by vinorelbine, were evaluated. Cohort 2, where pertuzumab and trastuzumab were administered in a single infusion, followed by vinorelbine, recruited after Cohort 1 was fully enrolled, will be reported later.

METHODS

In this multicenter, two-cohort, open-label, phase II study, patients with HER2-positive locally advanced or MBC who had not received chemotherapy or biological therapy for their advanced disease received 3-weekly pertuzumab (840 mg loading, 420 mg maintenance doses) and trastuzumab (8 mg/kg loading, 6 mg/kg maintenance doses), followed by vinorelbine (25 mg/m² initial dose, 30-35 mg/m² maintenance doses) on days 1 and 8 or 2 and 9 of each 3-weekly cycle. Study treatment was given until investigator-assessed disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed objective response rate (ORR) in patients with measurable disease at baseline per RECIST v1.1. Secondary endpoints included progression-free survival (PFS) and safety.

RESULTS

Cohort 1 enrolled 106 patients. Investigator-assessed ORR was 74.2% (95% CI 63.8-82.9) in intent-to-treat patients with measurable disease (89/106 [84.0%]). Median PFS was 14.3 months (95% CI 11.2-17.5) in the intent-to-treat population. Treatment was reasonably well tolerated, with no unexpected toxicities. Diarrhea (61/106 patients [57.5%]) and neutropenia (54/106 [50.9%]) were the most common adverse events (AEs); neutropenia (33/106 [31.1%]) and leukopenia (14/106 [13.2%]) were the most common grade ≥3 AEs. Serious AEs were reported in 32/106 (30.2%) patients. AEs led to study drug discontinuation in 36/106 patients (34.0%). Eighteen of 106 patients (17.0%) had AEs suggestive of congestive heart failure; however, there were no confirmed cases.

CONCLUSIONS

The vinorelbine, pertuzumab, and trastuzumab combination is active and reasonably well tolerated. This regimen offers an alternative for patients who cannot receive docetaxel for first-line treatment of HER2-positive locally advanced or MBC.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01565083 , registered on 26 March 2012.

Targeted Therapies in HER2-Overexpressing Metastatic Breast Cancer

Human epidermal growth factor receptor-2 (HER2) is amplified in 25-30% of breast cancers and is associated with aggressive disease and poorer survival. Multiple anti-HER2 targeted therapies have dramatically changed management and outcome of this subgroup, both in adjuvant and metastatic settings. Despite the improvement of survival thanks to trastuzumab, unclear mechanisms of resistance occur, which has led to the development of new anti-HER2 therapies such as lapatinib, pertuzumab, and trastuzumab emtansine (T-DM1). The optimal sequence of the available drugs is still not well established. All this progress raises the question of toxicity that need to be managed, especially with longer survival of patients. In this article, we review different anti-HER2 therapies used in HER2-positive m etastatic breast cancer.

Real-World Evidence: A Comparison of the Australian Herceptin Program and Clinical Trials of Trastuzumab for HER2-Positive Metastatic Breast Cancer

INTRODUCTION

Estimating the real-world cost-effectiveness of a new drug relies on understanding the differences between clinical trial data (pre-reimbursement) and clinical practice (post-reimbursement). This is important for decision makers when reviewing reimbursement decisions, prices, and considering other drugs for the same condition. Differences can arise from differences in patient characteristics, but also from the availability of new evidence and evolving treatment practices. This paper examines these issues using a case study.

METHODS

In 2001, the Australian Government funded trastuzumab for the treatment of HER2+ metastatic breast cancer through the Herceptin Program. The administrative arrangements of the Program resulted in rich observational data that captured information about patients treated with trastuzumab between 2001 and 2010 (n = 3830). The dataset included patient characteristics, dispensed medicines, medical service use and date of death.

RESULTS

Compared to participants in the clinical trials, patients were older, received more prior chemotherapies and a broader range of co-administered chemotherapies. Treatment practices differed from the clinical trials, but also changed over time. For example, in situ hybridization testing, rather than immunohistochemistry testing, and a three weekly administration schedule, rather than one weekly, were increasingly used. Compared to the clinical trials, patients administered trastuzumab with a concomitant chemotherapy generally experienced longer overall survival (151.3 weeks, 95 % CI: 142.6, 163.4), while those who received trastuzumab as a monotherapy experienced shorter overall survival (94.4 weeks, 95%CI: 86.4, 102.9). These findings may be due to a differing relative treatment effect in clinical practice, but may also be due to a range of other factors.

CONCLUSION

This analysis demonstrates the challenges for decision makers that arise because new evidence and evolving treatment practices create a gap between clinical trial data and real-world clinical practice and outcomes.

Over-treatment in metastatic breast cancer

Metastatic breast cancer is an incurable disease and the main goals of treatment are prolongation of survival and preservation/improvement of quality of life. Thus the main philosophy of treatment should be to use the least toxic methods, as long as they provide sufficient disease control. In ER-positive tumours this can be in many cases achieved by endocrine therapy; in HER2-positive cancers efficacy of backbone therapy can be enhanced by an anti-HER2 agent. In patients requiring chemotherapy, consecutive single agent regimen provide disease control of a duration at least comparable to multidrug regimen, at a cost of significantly lower toxicity and are a preferred strategy in the majority of cases. Available data demonstrate, however, that aggressive chemotherapy is still overused in many metastatic breast cancer patients. The objective of this manuscript is to critically review available data on treatment choices and sequence in metastatic breast cancer across all breast cancer subtypes in relation to possible overtreatment, including therapies which are not recommended by current guidelines or not even approved. Our aim is to provide guidance on applying these data to clinical practice, but also to describe various, often non-scientific factors influencing therapeutic decisions in an aim to identify areas requiring educational and possibly political actions.

First-line therapy in HER2 positive metastatic breast cancer: is the mosaic fully completed or are we missing additional pieces?

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in the biology of breast cancer and the subsequent development of HER2-targeted therapies, have dramatically improved clinical outcomes for women with early-stage and advanced HER2-positive breast cancer (BC).

HER-2 targeted therapies represent a major step forward in achieving the goal of delivering individualized targeted therapy for BC, and trastuzumab was the first anti-HER-2 strategy to be approved for treatment of HER-2 positive BC.

This review discusses the treatment of metastatic HER2-positive BC and describes efficacy and safety of novel anti-HER2 target therapies in first-line metastatic settings and the future challenges include refining such treatments, reducing toxicity and simultaneously developing innovative therapies. Furthermore, combinations of trastuzumab and drugs targeting the downstream pathway are described.

In the next future will be possible to use an ample armamentarium of combination therapies directed against HER2 and key signaling components integrated in the HER network. This approach will allow clinicians to tailor the management of the individual patient on the basis of tumor- specific biomarker profiles.

There is an urgent need for prospective biomarker-driven trials to identify patients for whom targeting is cost-effective.

Pharmacodynamics, pharmacokinetics and clinical efficacy of neratinib in HER2-positive breast cancer and breast cancer with HER2 mutations

INTRODUCTION

Despite the availability of several potent HER2-directed targeted agents, primary and acquired resistance continues to influence patient outcomes in HER2-positive breast cancer. Neratinib is an irreversible pan-HER tyrosine kinase inhibitor in late-phase clinical development.

AREAS COVERED

This review article focuses on neratinib in the treatment of HER2-positive breast cancer - early and metastatic stage - and HER2-mutant breast cancer, with particular emphasis on the pharmacokinetics and pharmacodynamics of the drug.

EXPERT OPINION

The phase III ExteNET trial shows that neratinib improves 2-year invasive disease-free survival after trastuzumab-based adjuvant therapy in early-stage HER2-positive breast cancer, and in particular HER2+/HR+ tumors. Survival data are awaited. The investigational role of neratinib in high-risk patients or conversely in de-escalation dual regimens with other anti-HER2 therapies and without chemotherapy are of interest. Phase II trials show that neratinib has efficacy, either as monotherapy or in combination with other chemotherapeutic or endocrine agents, in patients with HER2-positive metastatic breast cancer and in tumors harboring HER2 mutations. The role of neratinib in therapeutic algorithms of HER2-positive patients, as well as delaying CNS events, awaits the results of ongoing trials such as NALA. Diarrhea, the main toxicity of neratinib, can be effectively managed with early loperamide prophylaxis.