Real-World Impact of Adjuvant Anti-HER2 Treatment on Characteristics and Outcomes of Women With HER2-Positive Metastatic Breast Cancer in the ESME Program.

BACKGROUND: Although adjuvant cancer treatments increase cure rates, they may induce clonal selection and tumor resistance. Information still lacks as whether (neo)adjuvant anti-HER2 treatments impact the patterns of recurrence and outcomes of HER2-positive (HER2+) metastatic breast cancer (MBC). We aimed to assess this in the large multicenter ESME real-world database. PATIENTS AND METHODS: We examined the characteristics and outcomes (overall survival (OS) and progression-free survival under first-line treatment (PFS1)) of HER2+ patients with MBC from the French ESME program with recurrent disease, as a function of the previous receipt of adjuvant trastuzumab. Multivariable analyses used Cox models adjusted for baseline demographic, prognostic factors, adjuvant treatment received, and disease-free interval. RESULTS: Two thousand one hundred and forty-three patients who entered the ESME cohort between 2008 and 2017 had a recurrent HER2+ MBC. Among them, 56% had received (neo)adjuvant trastuzumab and 2.5% another anti-HER2 in this setting. Patients pre-exposed to trastuzumab were younger, had a lower disease-free interval, more HR-negative disease and more metastatic sites. While the crude median OS appeared inferior in patients exposed to adjuvant trastuzumab, as compared to those who did not (37.2 (95%CI 34.4-40.3) versus 53.5 months (95% CI: 47.6-60.1)), this difference disappeared in the multivariable model (HR = 1.05, 95%CI 0.91-1.22). The same figures were observed for PFS1. CONCLUSIONS: Among patients with relapsed HER2+ MBC, the receipt of adjuvant trastuzumab did not independently predict for worse outcomes when adjusted to other prognostic factors.

Neuregulin 4 Boosts the Efficacy of Anti-ERBB2 Neutralizing Antibodies.

ERBB4 is a tyrosine kinase receptor reported to exert both oncogenic and tumor suppressor activities. These paradoxical effects were suggested to stem from different ERBB4 homo-/hetero-dimers and/or isoforms. By stratifying breast cancer patients for clinical and molecular subtypes and ERBB4 mRNA abundance, we here report that higher ERBB4 levels correlate with longer relapse-free survival in breast cancer patients of HER2-enriched and luminal A molecular subtypes, proposing a cancer-protecting role for this receptor in these specific subgroups. We also observed that HER2-enriched breast cancers express intermediate ERBB4 mRNA levels compared to luminal and triple-negative/basal-like subgroups, which displayed the highest and the lowest levels, respectively. Inspired by these clinical data, we tested the activation of ERBB4 by Neuregulins as a potential anticancer strategy for HER2+ breast cancers. To this end, we employed two HER2+ breast cancer cellular models (BT474 and SKBR3), which express intermediate/high and low ERBB4 levels, respectively. Cell proliferation and motility were evaluated on these cellular models following treatments with Neuregulin 1 (NRG1), which activates both ERBB3 and ERBB4, or Neuregulin 4 (NRG4), which specifically activates ERBB4. Both NRG1 and NRG4 were used alone or in combination with anti-ERBB2 neutralizing antibodies, namely trastuzumab and pertuzumab. In vitro treatment with NRG1 on BT474 cells restrained cell growth and reduced the anti-proliferative efficacy of trastuzumab. In contrast, treatment with NRG1 on SKBR3 cells increased cell proliferation and migration, and partially or completely impaired the anti-proliferative/anti-migratory action of trastuzumab and/or pertuzumab. Importantly, in both the cell lines, treatment with NRG4 robustly potentiated the anti-proliferative action of trastuzumab and pertuzumab. Collectively, our data in HER2+ breast cancer cells highlight that NRG1 may exert both pro- and anti-proliferative effects, and may reduce the efficacy of anti-HER2 agents, whereas NRG4 may boost the anti-proliferative effects of anti-ERBB2 agents. We propose a provocative paradigm shift in the field of growth factors in cancer progression, suggesting the administration of ERBB4 ligands, such as Neuregulin 4, as a strategy to improve the efficacy of anti-ERBB2 agents.

Diarrhea With HER2-Targeted Agents in Cancer Patients: A Systematic Review and Meta-Analysis.

To fully investigate the diarrhea of human epidermal growth factor receptor 2 (HER2)-targeted agents in cancer patients. The relevant studies of the randomized, controlled trials (RCTs) in cancer patients treated with HER2-targeted agents were retrieved, and the systematic evaluation was conducted. EMBASE, MEDLINE, and PubMed were searched for articles published until August 2018. Forty-two RCTs and 21 633 patients were included. The current meta-analysis suggested that the use of HER2-targeted agents significantly increases the risk of developing all-grade diarrhea (RR, 2.78; 95%CI, 2.37-3.25; P < .00001) and high-grade diarrhea (RR, 4.89; 95%CI, 3.09-7.75; P < .00001). The RRs of all-grade diarrhea and high-grade diarrhea varied significantly according to drug type, control group, and treatment regimen. The RR of all-grade diarrhea varied significantly according to tumor type. Afatinib and neratinib tended to associate with the highest risk of all-grade diarrhea and high-grade diarrhea, respectively. Trastuzumab was associated with the lowest risk of diarrhea. Breast cancer patients tended to have a higher risk of all-grade diarrhea than patients with nonbreast cancer when receiving a HER2-targeted agent. The available data suggested that the use of HER2-targeted agents is associated with a significantly increased risk of diarrhea in cancer patients.

Efficacy and safety of targeted therapy for metastatic HER2-positive breast cancer in the first-line treatment: a Bayesian network meta-analysis.

PURPOSE: Numerous HER2-targeted therapy clinical trials have demonstrated efficacy and safety in the first-line treatment of metastatic breast cancer (MBC). However, the direct or indirect comparison of these drugs is unclear. This network meta-analysis can solve this issue to some extent. MATERIALS AND METHODS: PubMed, Embase, and the Cochrane Library were searched for Phase II/III randomized controlled trials (RCTs) on metastatic HER2-positive breast cancer for first-line treatment up to December 16, 2017. Paired meta-analyses were performed to compare the regimens directly with the TP (trastuzumab plus taxane) regimen. Bayesian network meta-analysis was used to synthesize available evidence of direct or indirect comparison. RESULTS: The database search identified 1,935 articles, among which 13 articles (10 RCTs) were eligible for the analysis involving 5,177 patients treated with 11 different regimens. The progression-free survival (PFS) in the Bayesian network meta-analysis suggested that the PTP (pertuzumab and trastuzumab plus taxane) regimen had the highest probability to be the preferred treatment (surface under the cumulative ranking [SUCRA]: 0.967) followed by the TPC (carboplatin and trastuzumab plus taxane) regimen (SUCRA: 0.923). The PTP regimen (SUCRA: 0.926) was similarly preferred for overall survival (OS). For objective response rate (ORR), the PTC regimen might be the optimal treatment (SUCRA: 0.935), followed by the PTP regimen. CONCLUSION: Overall, PTP might be the optimal first-line treatment for HER-2-positive MBC to improve the PFS and OS. Meanwhile, TPC might be most effective treatment in terms of the ORR. Regarding safety, the two regimens showed acceptable grade 3 or greater hematologic toxicity and heart failure.

Efficacy and safety of a combination of HER2-targeted agents as first-line treatment for metastatic HER2-positive breast cancer: a network meta-analysis.

BACKGROUND: Using network meta-analysis, we assessed the efficacy and safety of a combination regimen of HER2-targeted agents as first-line treatment for metastatic HER2-positive breast cancer. METHODS: We searched the Medline, Embase, and Cochrane Library electronic databases (through December 2016) for phase II/III randomized controlled trials that compared regimens of one or two HER2-targeted agents combined with trastuzumab or chemotherapy. A network meta-analysis including direct and indirect analyses was conducted in WinBUGS using fixed and random effects. Study quality was assessed following the Grading of Recommendations, Assessment, Development and Evaluations method. The primary outcome was overall survival. RESULTS: The network meta-analysis incorporated nine HER2-targeted regimens with 9 direct comparisons and 28 indirect comparisons for the main outcomes (8 studies; n = 3976). Combining direct and indirect effects showed significant increased efficacy of trastuzumab and docetaxel plus pertuzumab (TDP) over other regimens as first-line treatment. With indirect comparison of overall safety, TDP, TDM-1, and TDM-1 plus pertuzumab demonstrated a lower risk of grade 3-4 adverse events compared to other regimens. CONCLUSIONS: TDPs are a preferred first-line treatment for HER2-positive metastatic breast cancer compared with other target agent regimens.

Treatment patterns and survival in metastatic breast cancer patients by tumor characteristics.

OBJECTIVES: Study objectives were to compare the treatment patterns and clinical outcomes among metastatic breast cancer (mBC) patients by receipt of HER2-targeted agents and among subgroups of HER2-targeted agent users. RESEARCH DESIGN AND METHODS: Adult women newly diagnosed with mBC (index date) during 2008-2012 were selected from the Truven MarketScan databases and followed until end of enrollment or inpatient death. Patients with <12 months of data, pre-index primary cancers other than breast cancer, pregnancy, or HIV/AIDS were excluded. Study cohorts were users and nonusers of HER2-targeted agents and women with no treatment; and HER2-targeted agent subgroups by receipt of hormonal therapy (HT), de novo vs. recurrent status, and age group. Pre- and post-index breast cancer treatments were compared across cohorts. Relative risk of progression and death were evaluated among the subset of patients with mortality data. RESULTS: Of 18,059 eligible women selected, 14.6% were users of HER2-targeted agents, 71.1% were nonusers, and 14.3% untreated. HER2-targeted agent users received more aggressive cancer treatments compared to nonusers. HER2-targeted agent users were 33% more likely to progress and had a similar risk of death compared to nonusers. Among HER2-targeted agent subgroups, the risk of progression was 30% lower among HT+ patients vs. HT-, 32% lower for de novo vs. recurrent, and similar across age groups. The risk of death was 52% lower for HT+ vs. HT-, 35% lower for de novo vs. recurrent, and increased with age. LIMITATIONS: Identification of distant metastasis, tumor receptor expression and disease progression were based on claims data rather than on clinical assessment. CONCLUSIONS: Receipt of HER2-targeted agents (vs. non-HER2-targeted agents) was significantly associated with receipt of pre- and post-index breast cancer treatments. HER2-targeted agent users were more likely to progress but had a similar risk of death during follow-up. Among HER2-targeted agent subgroups, HT+ and de novo status were associated with a reduced risk of progression and death.

RON confers lapatinib resistance in HER2-positive breast cancer cells.

Lapatinib-resistance is a major problem for HER2-positive breast cancer treatment. SK-BR-3-LR, a lapatinib-resistant cell clone, was established from HER2-positive SK-BR-3 breast cancer cells following chronic exposure to lapatinib. The PI3K/AKT signaling pathway was demonstrated to be resistant to HER2 inhibition in SK-BR-3-LR cells. However, both small-molecular Recepteur d'Origine Nantais (RON) inhibitors and RON-targeted small interfering RNA (siRNA) effectively restored lapatinib sensitivity in these cells by inhibiting PI3K/AKT activation. Our results demonstrate for the first time the important role of RON in mediating lapatinib resistance and suggest that RON-targeted therapy may become a novel, promising therapeutic strategy after the failure of lapatinib treatment in patients with HER2-positive breast cancer.