Prognostic value of baseline neutrophil/lymphocyte ratio in HER2-positive metastatic breast cancer: exploratory analysis of data from the CLEOPATRA trial.

PURPOSE: This study aimed to evaluate the prognostic role of the baseline neutrophil/lymphocyte ratio (NLR) in HER2-positive metastatic breast cancer (MBC) patients treated with trastuzumab/pertuzumab. EXPERIMENTAL DESIGN: Data from 780 patients from the CLEOPATRA trial and 248 local patients were collected. Patients were divided into the low and high NLR subgroups by the NLR cutoff value. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) methods were used to control bias. Associations between the NLR and progression-free survival (PFS) and overall survival (OS) were analyzed. RESULTS: The baseline characteristics of the subgroups were well balanced after PSM and IPTW. A low baseline NLR was associated with better PFS and OS in the trastuzumab and docetaxel (TH) group in the unadjusted, PSM and IPTW models. After IPTW, a low NLR, versus a high NLR, was associated with improved PFS (HR 1.35, 95% CI 1.07-1.70, P = 0.012) and OS (HR 1.47, 95% CI 1.12-1.94, P = 0.006) in the TH group. In patients undergoing treatment with trastuzumab and pertuzumab and docetaxel (THP), a low baseline NLR was also correlated with better PFS but not OS across the three models. After IPTW, a low NLR was associated with better PFS (HR 1.52, 95% CI 1.20-1.93, P = 0.001) than a high NLR in the THP group. Multivariate analyses showed that a low baseline NLR was a predictor for PFS and OS in the TH group and for PFS in the THP group in all three models. In the real-world setting, a low baseline NLR was a predictor of better PFS among patients treated with docetaxel plus trastuzumab without or with pertuzumab in the multivariate model (P = 0.015 and 0.008, respectively). CONCLUSIONS: A low baseline NLR is associated with better survival outcomes among HER2-positive MBC patients receiving docetaxel plus trastuzumab/pertuzumab as first-line therapy.

Pruritus related to trastuzumab and pertuzumab in HER2 + breast cancer patients.

PURPOSE: The combination of trastuzumab and pertuzumab (HP) as part of a taxane-based regimen has shown benefit in the adjuvant and metastatic HER2 + breast cancer setting. In the CLEOPATRA trial, pruritus was reported in 11-17.6% of patients. The clinical phenotype and potential treatment strategies for this event have not been reported. METHODS: A retrospective review of 2583 patients receiving trastuzumab and pertuzumab for the treatment of HER2 + breast cancer from 11/23/2011 to 6/21/2021 was performed at Memorial Sloan Kettering Cancer Center (MSKCC). Patient demographics, pruritus characteristics, and treatments as documented in the electronic medical record (EMR) were included in this analysis. RESULTS: Of 2583 pts treated with HP, 122 (4.72%) with pruritus were identified. On average, patients experienced pruritus 319.0 days (8-3171) after initiation of HP. The upper extremities (67.4%), back (29.3%), lower extremities (17.4%), and shoulders (14.1%) were the most commonly affected regions. Grade 1/2 pruritus (97.6%) occurred in most cases. Patients responded primarily to treatment with topical steroids (52.2%), antihistamines (29.9%), emollients (20.9%), and gabapentinoids (16.4%). Of those with pruritus, 4 patients (3.3%) required treatment interruption or discontinuation. CONCLUSIONS: Pruritus is uncommon in patients on trastuzumab and pertuzumab, generally a chronic condition, with gabapentinoids or antihistamines representing effective therapies.

Long-term outcomes of neoadjuvant trastuzumab emtansine + pertuzumab (T-DM1 + P) and docetaxel + carboplatin + trastuzumab + pertuzumab (TCbHP) for HER2-positive primary breast cancer: results of the randomized phase 2 JBCRG20 study (Neo-peaks).

PURPOSE: The randomized phase 2 Neo-peaks study examined usefulness of neoadjuvant trastuzumab emtansine + pertuzumab (T-DM1 + P) following docetaxel + carboplatin + trastuzumab + pertuzumab (TCbHP) as compared with the standard TCbHP regimen. We previously reported that pCR rate after neoadjuvant therapy tended to be higher with TCbHP followed by T-DM1 + P. We conducted an exploratory analysis of prognosis 5 years after surgery. METHODS: Neoadjuvant treatment with TCbHP (6 cycles; group A), TCbHP (4 cycles) followed by T-DM1 + P (4 cycles; group B), and T-DM1 + P (4 cycles; group C, + 2 cycles in responders) were compared. Group C non-responders after 4 cycles were switched to an anthracycline-based regimen. We evaluated 5-year disease-free survival (DFS), distant DFS (DDFS), and overall survival (OS). RESULTS: Data from 203 patients (50, 52, and 101 in groups A-C, respectively) were analyzed. No significant intergroup differences were found for DFS, DDFS, or OS. The 5-year DFS rates (95% CI) were 91.8% (79.6-96.8%), 92.3% (80.8-97.0%), and 88.0% (79.9-93.0%) in groups A-C, respectively. TCbHP followed by T-DM1 + P and T-DM1 + P with response-guided addition of anthracycline therapy resulted in similar long-term prognosis to that of TCbHP. CONCLUSIONS: In patients who achieved pCR after neoadjuvant therapy with T-DM1 + P, omission of adjuvant anthracycline may be considered, whereas treatment should be adjusted for non-pCR patients with residual disease. T-DM1 + P with response-guided treatment adjustment may be useful for minimizing toxicity. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: UMIN-CTR, UMIN000014649, prospectively registered July 25, 2014. Some of the study results were presented as a Mini Oral session at the ESMO Breast Cancer 2023 (Berlin, Germany, 11-13 May 2023).

Time trends in real-world treatment patterns and survival in patients diagnosed with de novo HER2+ metastatic breast cancer: an analysis of the SONABRE registry.

PURPOSE: The aim was to determine whether the real-world first-line progression-free survival (PFS) of patients diagnosed with de novo human epidermal growth factor receptor 2 positive (HER2+) advanced breast cancer (ABC) has improved since the introduction of pertuzumab in 2013. In addition to PFS, we aimed to determine differences in overall survival (OS) and the use of systemic and locoregional therapies. METHODS: Included were patients systemically treated for de novo HER2+ ABC in ten hospitals in 2008-2017 from the SONABRE Registry (NCT-03577197). First-line PFS and OS in 2013-2017 versus 2008-2012 was determined using Kaplan-Meier analyses and multivariable Cox proportional hazards modelling. First-given systemic therapy and the use of locoregional therapy within the first year following diagnosis were determined per period of diagnosis. RESULTS: Median and five-year PFS were 26.6 months and 24% in 2013-2017 (n = 85) versus 14.5 months and 10% in 2008-2012 (n = 81) (adjusted HR = 0.65, 95%CI:0.45-0.94). Median and five-year OS were 61.2 months and 51% in 2013-2017 versus 26.1 months and 28% in 2008-2012 (adjusted HR = 0.55, 95%CI:0.37-0.81). Of patients diagnosed in 2013-2017 versus 2008-2012, 84% versus 60% received HER2-targeted therapy and 59% versus 0% pertuzumab-based therapy as first-given therapy. Respectively, 27% and 23% of patients underwent locoregional breast surgery, and 6% and 7% surgery of a metastatic site during the first year following diagnosis. CONCLUSION: The prognosis of patients with de novo HER2 + ABC has improved considerably. Since 2013 one in four patients were alive and free from progression on first-given therapy for at least five years.

Neoadjuvant anthracycline-based (5-FEC) or anthracycline-free (docetaxel/carboplatin) chemotherapy plus trastuzumab and pertuzmab in HER2 + BC patients according to their TOP2A: a multicentre, open-label, non-randomized phase II trial.

PURPOSE: Previous studies have reported the benefit of dual HER2-targeting combined to neoadjuvant chemotherapy in HER2-amplified breast cancer (HER2 + BC). Moreover, besides the cardiac toxicity following their association to Trastuzumab, anthracyclines chemotherapy may not profit all patients. The NeoTOP study was designed to evaluate the complementary action of Trastuzumab and Pertuzumab, and the relevance of an anthracycline-based regimen according to TOP2A amplification status. METHODS: Open-label, multicentre, phase II study. Eligible patients were aged ≥ 18 with untreated, operable, histologically confirmed HER2 + BC. After centralized review of TOP2A status, TOP2A-amplified (TOP2A+) patients received FEC100 for 3 cycles then 3 cycles of Trastuzumab (8 mg/kg then 6 mg/kg), Pertuzumab (840 mg/kg then 420 mg/kg), and Docetaxel (75mg/m2 then 100mg/m2). TOP2A-not amplified (TOP2A-) patients received 6 cycles of Docetaxel (75mg/m2) and Carboplatin (target AUC 6 mg/ml/min) plus Trastuzumab and Pertuzumab. Primary endpoint was pathological Complete Response (pCR) using Chevallier's classification. Secondary endpoints included pCR (Sataloff), Progression-Free Survival (PFS), Overall Survival (OS), and toxicity. RESULTS: Out of 74 patients, 41 and 33 were allocated to the TOP2A + and TOP2A- groups respectively. pCR rates (Chevallier) were 74.4% (95%CI: 58.9-85.4) vs. 71.9% (95%CI: 54.6-84.4) in the TOP2A + vs. TOP2A- groups. pCR rates (Sataloff), 5-year PFS and OS were 70.6% (95%CI: 53.8-83.2) vs. 61.5% (95%CI: 42.5-77.6), 82.4% (95%CI: 62.2-93.6) vs. 100% (95%CI: 74.1-100), and 90% (95%CI: 69.8-98.3) vs. 100% (95%CI: 74.1-100). Toxicity profile was consistent with previous reports. CONCLUSION: Our results showed high pCR rates with Trastuzumab and Pertuzumab associated to chemotherapy. They were similar in TOP2A + and TOP2A- groups and the current role of neoadjuvant anthracycline-based chemotherapy remains questioned. TRIAL REGISTRATION NUMBER: NCT02339532 (registered on 14/12/14).

heredERA Breast Cancer: a phase III, randomized, open-label study evaluating the efficacy and safety of giredestrant plus the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection in patients with previously untreated HER2-positive, estrogen receptor-positive locally advanced or metastatic breast cancer.

BACKGROUND: HER2-positive, estrogen receptor-positive breast cancer (HER2+, ER+ BC) is a distinct disease subtype associated with inferior response to chemotherapy plus HER2-targeted therapy compared with HER2+, ER-negative BC. Bi-directional crosstalk leads to cooperation of the HER2 and ER pathways that may drive treatment resistance; thus, simultaneous co-targeting may optimize treatment impact and survival outcomes in patients with HER2+, ER+ BC. First-line (1L) treatment for patients with HER2+ metastatic BC (mBC) is pertuzumab, trastuzumab, and taxane chemotherapy. In clinical practice, dual HER2 blockade plus a fixed number of chemotherapy cycles are given as induction therapy to maximize tumor response, with subsequent HER2-targeted maintenance treatment given as a more tolerable regimen for long-term disease control. For patients whose tumors co-express ER, maintenance endocrine therapy (ET) can be added, but uptake varies due to lack of data from randomized clinical trials investigating the superiority of maintenance ET plus dual HER2 blockade versus dual HER2 blockade alone. Giredestrant, a novel oral selective ER antagonist and degrader, shows promising clinical activity and manageable safety across phase I-II trials of patients with ER+, HER2-negative BC, with therapeutic potential in those with HER2 co-expression. METHODS: This phase III, randomized, open-label, two-arm study aims to recruit 812 patients with HER2+, ER+ locally advanced (LA)/mBC into the induction phase (fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection [PH FDC SC] plus a taxane) to enable 730 patients to be randomized 1:1 to the maintenance phase (giredestrant plus PH FDC SC or PH FDC SC [plus optional ET]), stratified by disease site (visceral versus non-visceral), type of LA/metastatic presentation (de novo versus recurrent), best overall response to induction therapy (partial/complete response versus stable disease), and intent to give ET (yes versus no). The primary endpoint is investigator-assessed progression-free survival. Secondary endpoints include overall survival, objective response rate, clinical benefit rate, duration of response, safety, and patient-reported outcomes. DISCUSSION: heredERA BC will address whether giredestrant plus dual HER2 blockade is superior to dual HER2 blockade alone, to inform the use of this combination in clinical practice for maintenance 1L treatment of patients with HER2+, ER+ LA/mBC. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05296798; registered on March 25, 2022. Protocol version 3.0 (November 18, 2022). SPONSOR: F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124 4070, Basel, Switzerland.

Safety and efficacy analysis of neoadjuvant pertuzumab, trastuzumab and standard chemotherapy for HER2-positive early breast cancer: real-world data from NeoPowER study.

BACKGROUND: The addition of pertuzumab (P) to trastuzumab (H) and standard chemotherapy (CT) as neoadjuvant treatment (NaT) for patients with HER2 + breast cancer (BC), has shown to increase the pathological complete response (pCR) rate, without main safety concerns. The aim of NeoPowER trial is to evaluate safety and efficacy of P + H + CT in a real-world population. METHODS: We retrospectively reviewed the medical records of stage II-III, HER2 + BC patients treated with NaT: who received P + H + CT (neopower group) in 5 Emilia Romagna institutions were compared with an historical group who received H + CT (control group). The primary endpoint was the safety, secondary endpoints were pCR rate, DRFS and OS and their correlation to NaT and other potential variables. RESULTS: 260 patients were included, 48% received P + H + CT, of whom 44% was given anthraciclynes as part of CT, compared to 83% in the control group. The toxicity profile was similar, excluding diarrhea more frequent in the neopower group (20% vs. 9%). Three patients experienced significant reductions in left ventricular ejection fraction (LVEF), all receiving anthracyclines. The pCR rate was 46% (P + H + CT) and 40% (H + CT) (p = 0.39). The addition of P had statistically correlation with pCR only in the patients receiving anthra-free regimens (OR = 3.05,p = 0.047). Preoperative use of anthracyclines (OR = 1.81,p = 0.03) and duration of NaT (OR = 1.18,p = 0.02) were statistically related to pCR. 12/21 distant-relapse events and 14/17 deaths occurred in the control group. Patients who achieve pCR had a significant increase in DRFS (HR = 0.23,p = 0.009). CONCLUSIONS: Adding neoadjuvant P to H and CT is safe. With the exception of diarrhea, rate of adverse events of grade > 2 did not differ between the two groups. P did not increase the cardiotoxicity when added to H + CT, nevertheless in our population all cardiac events occurred in patients who received anthracycline-containing regimens. Not statistically significant, higher pCR rate is achievable in patients receiving neoadjuvant P + H + CT. The study did not show a statistically significant correlation between the addition of P and long-term outcomes.

HER2-Positive Metastatic Colorectal Cancer.

OPINION STATEMENT: Targeted treatment strategies are available for human epidermal growth factor receptor 2 (HER2)-positive (amplified and/or overexpressed) metastatic colorectal cancer (mCRC), and HER2 testing is indicated in patients with mCRC. At present, standard of care first-line treatment for those with HER2-positive mCRC remains chemotherapy in combination with epidermal growth factor receptor (EGFR) inhibitors or bevacizumab, depending on RAS/BRAF mutational status and tumor sidedness. HER2-targeted agents should be considered for those with RAS/BRAF wild-type disease in subsequent-line treatment and in first-line treatment for patients not appropriate for intensive therapy. While the choice of anti-HER2 therapy is empiric given lack of head-to-head comparisons, the combination of trastuzumab plus tucatinib has received FDA accelerated approval for use in this setting and is generally the authors' preference. Trastuzumab plus lapatinib, trastuzumab plus pertuzumab, and trastuzumab deruxtecan (T-DXd) also have evidence of efficacy in this setting. As T-DXd has demonstrated activity following treatment with other HER2-targeted regimens and carries an increased risk of high-grade toxicities, the authors favor reserving it for use after progression on prior anti-HER2 therapy. HER2-targeted therapies that inhibit signal transduction appear to have limited activity in those with RAS mutations, including trastuzumab-containing regimens. However, the antibody drug conjugate T-DXd has some data showing efficacy in this setting, and the authors would consider T-DXd in subsequent-line therapy for HER2-positive, RAS-mutated mCRC. Several areas of uncertainty remain regarding how to best utilize HER2-targeted therapies in mCRC. These include the optimal sequence of anti-HER2 therapies with chemotherapy and anti-EGFR therapies, the optimal combination partners for anti-HER2 therapies, and the incorporation of predictive biomarkers to guide use of anti-HER2 therapies. Results of ongoing studies may thus alter the treatment paradigm above in the coming years.

Discovery of novel HER2 targeting peptide-camptothecin conjugates with effective suppression for selective cancer treatment.

Due to the strong selectivity and permeability of tumor tissue, anti-cancer peptide-drug conjugates (PDCs) can accumulate high concentration of toxic payloads at the target, effectively killing tumor cells. This approach holds great promise for tumor-targeted treatment. In our previous study, we identified the optimal peptide P1 (NPNWGRSWYNQRFK) targeting HER2 from pertuzumab, a monoclonal antibody that blocks the HER2 signaling pathway. Here, a series of PDCs were constructed through connecting P1 and CPT with different linkers. Among these, Z8 emerged as the optimal compound, demonstrating good antitumor activity and targeting ability in biological activity tests. Z8 exhibited IC50 values of 1.04 ± 0.24 µM and 1.91 ± 0.71 µM against HER2-positive SK-BR-3 and NCI-N87 cells, respectively. Moreover, superior antitumor activity and higher biosafety of Z8 were observed compared to the positive control CPT in vivo, suggesting a novel idea for the construction of PDCs.

Disrupting EGFR-HER2 Transactivation by Pertuzumab in HER2-Positive Cancer: Quantitative Analysis Reveals EGFR Signal Input as Potential Predictor of Therapeutic Outcome.

Pertuzumab (Perjeta®), a humanized antibody binding to the dimerization arm of HER2 (Human epidermal growth factor receptor-2), has failed as a monotherapy agent in HER2 overexpressing malignancies. Since the molecular interaction of HER2 with ligand-bound EGFR (epidermal growth factor receptor) has been implied in mitogenic signaling and malignant proliferation, we hypothesized that this interaction, rather than HER2 expression and oligomerization alone, could be a potential molecular target and predictor of the efficacy of pertuzumab treatment. Therefore, we investigated static and dynamic interactions between HER2 and EGFR molecules upon EGF stimulus in the presence and absence of pertuzumab in HER2+ EGFR+ SK-BR-3 breast tumor cells using Förster resonance energy transfer (FRET) microscopy and fluorescence correlation and cross-correlation spectroscopy (FCS/FCCS). The consequential activation of signaling and changes in cell proliferation were measured by Western blotting and MTT assay. The autocorrelation functions of HER2 diffusion were best fitted by a three-component model corrected for triplet formation, and among these components the slowly diffusing membrane component revealed aggregation induced by EGFR ligand binding, as evidenced by photon-counting histograms and co-diffusing fractions. This aggregation has efficiently been prevented by pertuzumab treatment, which also inhibited the post-stimulus interaction of EGFR and HER2, as monitored by changes in FRET efficiency. Overall, the data demonstrated that pertuzumab, by hindering post-stimulus interaction between EGFR and HER2, inhibits EGFR-evoked HER2 aggregation and phosphorylation and leads to a dose-dependent decrease in cell proliferation, particularly when higher amounts of EGF are present. Consequently, we propose that EGFR expression on HER2-positive tumors could be taken into consideration as a potential biomarker when predicting the outcome of pertuzumab treatment.

Combining Endocrine Therapy with Trastuzumab Emtansine Improves Progression-Free Survival and Overall Survival in HER2-Positive, Hormone Receptor-Positive Metastatic Breast Cancer.

Background and Objectives: Patients with human epidermal growth factor receptor 2 (HER2) -positive, hormone receptor-positive (HR-positive) metastatic breast cancer (MBC) usually undergo trastuzumab emtansine (T-DM1) therapy in subsequent lines. Combining endocrine therapy (ET) with T-DM1 can improve treatment outcomes in this subtype. Therefore, this study aimed to investigate the benefits of using T-DM1 with ET in HER2-positive and HR-positive MBC. This study was the first to investigate the benefits of combining ET with T-DM1. Material and Methods: This study analyzed the medical records of patients with HER2-positive and HR-positive MBC who were treated with T-DM1 from June 2010 to December 2021. The patients were divided into groups based on whether they received concomitant ET with T-DM1. The primary endpoint was to determine the progression-free survival (PFS), while the secondary endpoints were overall survival (OS), objective response rate, and safety of the treatment. Results: Our analysis examined 88 patients, of whom 32 (36.4%) were treated with T-DM1 in combination with ET. The combination therapy showed a significant improvement in median PFS (15.4 vs. 6.4 months; p = 0.00004) and median OS (35.0 vs. 23.1 months; p = 0.026) compared to T-DM1 alone. The ORR was also higher in the combination group (65.6% vs. 29.3%; p = 0.026). Patients treated with pertuzumab priorly had reduced median PFS on T-DM1 compared to those who were not treated with pertuzumab (11.7 vs. 5.4 months, respectively; p < 0.01). T-DM1 demonstrated better median PFS in HER2 3+ patients compared to HER2 2+ patients, with an amplification ratio of >2.0 (10.8 vs 5.8 months, respectively; p = 0.049). The safety profiles were consistent with previous T-DM1 studies. Conclusions: The combination of T-DM1 with ET can significantly improve PFS and OS in patients with HER2-positive and HR-positive MBC. Our study suggests that prior pertuzumab treatment plus trastuzumab treatment might decrease T-DM1 efficacy.

Pyrotinib is effective in both trastuzumab-sensitive and primary resistant HER2-positive breast tumors.

Objective: Primary resistance to trastuzumab frequently occurs in human epidermal growth factor receptor 2 (HER2)-positive (+) breast cancer patients and remains a clinical challenge. Pyrotinib is a novel tyrosine kinase inhibitor that has shown efficacy in the treatment of HER2+ breast cancer. However, the efficacy of pyrotinib in HER2+ breast cancer with primary trastuzumab resistance is unknown. Methods: HER2+ breast cancer cells sensitive or primarily resistant to trastuzumab were treated with trastuzumab, pyrotinib, or the combination. Cell proliferation, migration, invasion, and HER2 downstream signal pathways were analyzed. The effects of pyrotinib plus trastuzumab and pertuzumab plus trastuzumab were compared in breast cancer cells in vitro and a xenograft mouse model with primary resistance to trastuzumab. Results: Pyrotinib had a therapeutic effect on trastuzumab-sensitive HER2+ breast cancer cells by inhibiting phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and rat sarcoma virus (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase (MAPK)/extracellular-signal regulated kinase (ERK) pathways. In primary trastuzumab-resistant cells, pyrotinib inhibited cell growth, migration, invasion, and HER2 downstream pathways, whereas trastuzumab had no effects. The combination with trastuzumab did not show increased effects compared with pyrotinib alone. Compared with pertuzumab plus trastuzumab, pyrotinib plus trastuzumab was more effective in inhibiting cell proliferation and HER2 downstream pathways in breast cancer cells and tumor growth in a trastuzumab-resistant HER2+ breast cancer xenograft model. Conclusions: Pyrotinib-containing treatments exhibited anti-cancer effects in HER2+ breast cancer cells sensitive and with primary resistance to trastuzumab. Notably, pyrotinib plus trastuzumab was more effective than trastuzumab plus pertuzumab in inhibiting tumor growth and HER2 downstream pathways in HER2+ breast cancer with primary resistance to trastuzumab. These findings support clinical testing of the therapeutic efficacy of dual anti-HER2 treatment combining an intracellular small molecule with an extracellular antibody.

Tumor biomarkers and efficacy in patients treated with trastuzumab emtansine + pertuzumab versus standard of care in HER2-positive early breast cancer: an open-label, phase III study (KRISTINE).

BACKGROUND: KRISTINE is an open-label, phase III study of trastuzumab emtansine + pertuzumab (T-DM1 + P) versus docetaxel + carboplatin + trastuzumab + pertuzumab (TCH + P) in patients with HER2-positive, stage II-III breast cancer. We investigated the association of biomarkers with clinical outcomes in KRISTINE. METHODS: Patients were randomized to receive neoadjuvant T-DM1 + P or TCH + P and assessed for pathologic complete response (pCR; ypT0/is, ypN0). HER2 status (per central assessment), hormone receptor status, PIK3CA mutation status, HER2/HER3 mRNA levels, tumor-infiltrating lymphocyte levels, PD-L1 status, and NanoString data were analyzed. pCR rates by treatment arm were compared across biomarker subgroups. Analyses were descriptive. RESULTS: Biomarker analyses included data from all 444 patients (T-DM1 + P, n = 223; TCH + P, n = 221) enrolled in KRISTINE. Biomarker distribution was balanced across treatment arms. All subgroups with higher HER2 amplification/expression and immune marker levels showed numerically higher pCR rates in both arms. Mutated versus non-mutated PIK3CA tumors were associated with numerically lower pCR rates in the T-DM1 + P arm but not in the TCH + P arm. In a multivariate analysis, Prediction Analysis of Microarray with the 50-gene classifier (PAM50) HER2-enriched subtype, HER2 gene ratio ≥ 4, and PD-L1-positive status positively influenced the pCR rate. Biomarkers associated with lower pCR rates (e.g., low HER2 levels, positive hormone receptor status, mutated PIK3CA) were more likely to co-occur. Dynamic on-treatment biomarker changes were observed. Differences in the treatment effects for T-DM1 + P versus TCH + P were similar to those observed in the intent-to-treat population for the majority of the biomarker subgroups. CONCLUSIONS: Although our biomarker analysis did not identify a subgroup of patients that benefited from neoadjuvant T-DM1 + P versus TCH + P, the data revealed that patients with higher HER2 amplification/expression and immune marker levels had improved response irrespective of treatment arm. These analyses confirm the role of HER2 tumor biology and the immune microenvironment in influencing pCR in the neoadjuvant setting and reaffirm the molecular diversity of HER2-positive breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT02131064. Registered 06 May 2014.

Pertuzumab study in the neoadjuvant setting for HER2-positive nonmetastatic breast cancer in Australia (PeRSIA).

The pertuzumab study in the neoadjuvant setting for HER2+ nonmetastatic breast cancer in Australia (PeRSIA-ML39622) is an analysis of safety and effectiveness data from the pertuzumab patient registry. Although the prognosis of patients with early stage HER2+ breast cancer has been greatly improved by advances in chemotherapy approximately 25% to 30% of patients develop recurrent disease. Our study aimed to examine the effectiveness of neoadjuvant pertuzumab on surgical outcomes, describe the medium-term effectiveness outcomes of patients treated with pertuzumab, and describe the planned and actual anticancer treatment regimens that patients received. Deidentified data were collected from the patients' medical records and entered into REDCap, between March 2018 and July 2019 (n = 95). The adverse events (AEs) reported most frequently were diarrhea (20; 21.1%), rash (4; 4.2%), and LVSD (4; 4.2%; two patients during neoadjuvant treatment and two patients during adjuvant treatment). AEs, ≥Grade 3 were diarrhea (2; 2.1%) and LVSD (1; 1.1%). Following surgery, a breast pathological complete response (bpCR) was achieved in 65 patients (70.7%; 95% CI: 60.2%-79.7%) and total pathological complete response (tpCR) in 59 patients (64.1%; 95% CI: 53.4%-73.9%). All patients who did not achieve a tpCR obtained a partial response (33/92, 35.9%). Our study is the first to capture real-world data on the use of pertuzumab in the neoadjuvant setting in Australia. The effectiveness and safety data are consistent with those reported in clinical trials of pertuzumab in patients with HER2+ breast cancer, with no new safety concerns.

Phase 2 prospective open label study of neoadjuvant nab-paclitaxel, trastuzumab, and pertuzumab in patients with HER2-positive primary breast cancer.

BACKGROUND: The objective of this study was to evaluate the safety and efficacy of nab-paclitaxel, trastuzumab, and pertuzumab as neoadjuvant therapy (NAT) in patients with human epidermal growth factor receptor 2 HER2+ breast cancer (HER2+ BC) to determine pathologic complete response (pCR), invasive disease-free survival (iDFS), and overall survival. METHODS: Forty-five patients with HER2+ BC Stages II-III were to be enrolled from 2013 to 2017. Patients were treated with weekly nab-paclitaxel (100 mg/m2 intravenously), weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg), and six cycles of pertuzumab (840 mg loading dose, then 420 mg intravenously day 1 every 21 days). RESULTS: Median follow-up was 60 months (95% CI, 32.3-55.6) and pCR was 29/45 (64%). The 5-year iDFS for patients who achieved pCR (N = 29) was 96.3% (95% CI, 76.5-99.5) and non-pCR patients (N = 16) was 74.3% (95% CI, 39.1-91.0). The 5-year overall survival (N = 45) was 94.1% (95% CI, 77.6-98.5). Based on hormonal status, the 5-year iDFS for HR+ pCR patients (N = 14) was 92.3% (95% CI, 56.6-98.9) and for HR- (N = 15) was 100% (p = .3). CONCLUSIONS: This anthracycline/carboplatin-free regimen with nab-paclitaxel achieved a pCR rate of 64% in patients with HER2+ BC. The 5-year iDFS in patients with and without pCR was 96.3% and 74.3%, respectively. The pCR rate is comparable with docetaxel, carboplatin, trastuzumab, and pertuzumab therapy in the NAT setting, but with fewer treatment-associated toxicities. This finding suggests the possibility of safe avoidance of anthracyclines and carboplatin as components of NAT in patients with HER2+ BC.

Using the HER2/CEP17 FISH Ratio to Predict Pathologic Complete Response Following Neoadjuvant Anti-HER2 Doublet Therapy in HER2+ Breast Cancer.

BACKGROUND: Clinical trials of HER2-directed therapy that omit neoadjuvant conventional chemotherapy for HER+ breast cancer demonstrate that a subset of patients still obtains a pCR. Identifying tumor characteristics which predict pCR may help select patients for de-escalated neoadjuvant dual HER2-targeted treatment without chemotherapy. This is the first study evaluating the HER2/CEP17 ratio by FISH as a biomarker to predict pCR among patients who received neoadjuvant anti-HER2 regimens without chemotherapy. PATIENTS AND METHODS: Data from patients with locally advanced HER2+ breast cancer who received neoadjuvant dual HER2-targeted therapy without conventional chemotherapy from a single center was retrospectively reviewed. All patients were enrolled in one of 3 clinical trials evaluating chemotherapy de-escalation. Logistic regression modeling assessed for a relationship between the HER2/CEP17 FISH ratio obtained from baseline tissue biopsy and pCR based on pathology at the time of definitive breast surgery following neoadjuvant treatment. RESULTS: Following neoadjuvant treatment with dual HER2-targeted therapies in 56 patients, the probability of pCR was 73% among patients with a HER2 ratio of 13.1 compared to a probability of 38% among patients with HER2 ratio of 5.5 (OR 4.14, 95% CI 1.44-11.89; P = .012). This positive association persisted after controlling for different treatment regimens administered (OR 2.87, 95% CI 0.9-9.18, P = .020). CONCLUSIONS: These data found a positive association between the HER2/CEP17 FISH ratio and pCR following neoadjuvant dual HER2-targeted therapy without chemotherapy. Larger prospective studies are needed to validate the HER2 ratio as a biomarker to select patients for neoadjuvant dual anti-HER2 therapy without chemotherapy.

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.

Association of HER2DX with pathological complete response and survival outcomes in HER2-positive breast cancer.

BACKGROUND: The HER2DX genomic test predicts pathological complete response (pCR) and survival outcome in early-stage HER2-positive (HER2+) breast cancer. Here, we evaluated the association of HER2DX scores with (i) pCR according to hormone receptor status and various treatment regimens, and (ii) survival outcome according to pCR status. MATERIALS AND METHODS: Seven neoadjuvant cohorts with HER2DX and clinical individual patient data were evaluated (DAPHNe, GOM-HGUGM-2018-05, CALGB-40601, ISPY-2, BiOnHER, NEOHER and PAMELA). All patients were treated with neoadjuvant trastuzumab (n = 765) in combination with pertuzumab (n = 328), lapatinib (n = 187) or without a second anti-HER2 drug (n = 250). Event-free survival (EFS) and overall survival (OS) outcomes were available in a combined series of 268 patients (i.e. NEOHER and PAMELA) with a pCR (n = 118) and without a pCR (n = 150). Cox models were adjusted to evaluate whether HER2DX can identify patients with low or high risk beyond pCR status. RESULTS: HER2DX pCR score was significantly associated with pCR in all patients [odds ratio (OR) per 10-unit increase = 1.59, 95% confidence interval 1.43-1.77; area under the ROC curve = 0.75], with or without dual HER2 blockade. A statistically significant increase in pCR rate due to dual HER2 blockade over trastuzumab-only was observed in HER2DX pCR-high tumors treated with chemotherapy (OR = 2.36 (1.09-5.42). A statistically significant increase in pCR rate due to multi-agent chemotherapy over a single taxane was observed in HER2DX pCR-medium tumors treated with dual HER2 blockade (OR = 3.11, 1.54-6.49). The pCR rates in HER2DX pCR-low tumors were ≤30.0% regardless of treatment administered. After adjusting by pCR status, patients identified as HER2DX low-risk had better EFS (P < 0.001) and OS (P = 0.006) compared with patients with HER2DX high-risk. CONCLUSIONS: HER2DX pCR score and risk score might help identify ideal candidates to receive neoadjuvant dual HER2 blockade in combination with a single taxane in early-stage HER2+ breast cancer.

Pertuzumab, trastuzumab, and docetaxel for Chinese patients with previously untreated HER2-positive locally recurrent or metastatic breast cancer (PUFFIN): final analysis of a phase III, randomized, double-blind, placebo-controlled study.

PURPOSE: PUFFIN (NCT02896855), a Chinese bridging study in patients with previously untreated HER2-positive locally recurrent or metastatic breast cancer, assessed consistency of efficacy and safety of pertuzumab plus trastuzumab and docetaxel versus placebo, trastuzumab, and docetaxel, with CLEOPATRA (NCT00567190). METHODS: Eligible patients, n = 243, were randomized 1:1, stratified by visceral disease and hormone receptor status, to pertuzumab, trastuzumab, and docetaxel or placebo, trastuzumab, and docetaxel. PRIMARY ENDPOINT: investigator-assessed progression-free survival (PFS). Secondary endpoints: safety and overall survival (OS). After primary analysis, patients could cross over to the pertuzumab arm. RESULTS: Updated median PFS: 16.5 months (pertuzumab arm) and 12.5 months (placebo arm), with a hazard ratio (HR) of 0.60 [95% confidence interval (CI) 0.45, 0.81; p = 0.0008]. Median OS was not reached in either arm; the OS HR was 0.68 (95% CI 0.45, 1.03; p = 0.0658). Safety was similar in both arms with no new safety signals: 73.8% (pertuzumab arm) and 69.2% (placebo arm) experienced grade ≥ 3 adverse events. No heart failure, symptomatic left ventricular systolic dysfunction, or left ventricular ejection fraction decline of < 40% were reported. CONCLUSIONS: The PUFFIN final analysis showed, per the primary analysis, that overall efficacy of pertuzumab plus trastuzumab and docetaxel was consistent with CLEOPATRA. Safety remained consistent with the known pertuzumab profile. Overall, PUFFIN contributes to the totality of data with pertuzumab in previously untreated HER2-positive locally recurrent or metastatic breast cancer and supports the favorable benefit-risk profile of pertuzumab in Chinese patients. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02896855, registered 7 September 2016.

Outcomes for the first four lines of therapy in patients with HER2-positive advanced breast cancer: results from the SONABRE registry.

PURPOSE: We assessed the systemic treatment choices and outcomes in patients diagnosed with human epidermal growth factor receptor-2-positive (HER2 +) advanced breast cancer (ABC), for the first four lines of systemic therapy and by hormone receptor (HR) status. METHODS: We identified 330 patients diagnosed with HER2 + ABC in 2013-2018 in the Southeast of The Netherlands, of whom 64% with HR + /HER2 + and 36% with HR-/HER2 + disease. Overall survival (OS) from start of therapy was calculated using the Kaplan-Meier method. RESULTS: In real world, 95% of patients with HR + /HER2 + and 74% of patients with HR-/HER2 + disease received systemic therapy. In HR + /HER2 + disease, use of endocrine, chemo- and HER2-targeted therapy was , respectively, 64%, 46% and 60% in first line, and 39%, 64% and 75% in fourth line. In HR-/HER2 + disease, 91-96% of patients received chemotherapy and 77-91% HER2-targeted therapy, irrespective of line of therapy. In patients with HR + /HER2 + disease, median OS was 34.9 months (95%CI:25.8-44.0) for the first line and 12.8 months (95%CI:10.7-14.9) for the fourth line. In HR-/HER2 + disease, median OS was 39.9 months (95%CI:23.9-55.8) for the first line and 15.2 months (95%CI:10.9-19.5) for the fourth line. For patients treated with first-line pertuzumab, trastuzumab plus chemotherapy, median OS was not reached at 56.0 months in HR + /HER2 + disease and 48.4 months (95%CI:32.6-64.3) in HR-/HER2 + disease. CONCLUSION: Survival times for later lines of therapy are surprisingly long and justify the use of multiple lines of systemic therapy in well-selected patients with HER2 + ABC. Our real-world evidence adds valuable observations to the accumulating evidence that within HER2 + ABC, the HR status defines two distinct disease subtypes.