Neoadjuvant-adjuvant pertuzumab in HER2-positive early breast cancer: final analysis of the randomized phase III PEONY trial.

The randomized, multicenter, double-blind, placebo-controlled, phase III PEONY trial (NCT02586025) demonstrated significantly improved total pathologic complete response (primary endpoint) with dual HER2 blockade in HER2-positive early/locally advanced breast cancer, as previously reported. Here, we present the final, long-term efficacy (secondary endpoints: event-free survival, disease-free survival, overall survival) and safety analysis (62.9 months' median follow-up). Patients (female; n = 329; randomized 2:1) received neoadjuvant pertuzumab/placebo with trastuzumab and docetaxel, followed by adjuvant 5-fluorouracil, epirubicin, and cyclophosphamide, then pertuzumab/placebo with trastuzumab until disease recurrence or unacceptable toxicity, for up to 1 year. Five-year event-free survival estimates are 84.8% with pertuzumab and 73.7% with placebo (hazard ratio 0.53; 95% confidence interval 0.32-0.89); 5-year disease-free survival rates are 86.0% and 75.0%, respectively (hazard ratio 0.52; 95% confidence interval 0.30-0.88). Safety data are consistent with the known pertuzumab safety profile and generally comparable between arms, except for diarrhea. Limitations include the lack of ado-trastuzumab emtansine as an option for patients with residual disease and the descriptive nature of the secondary, long-term efficacy endpoints. PEONY confirms the positive benefit:risk ratio of neoadjuvant/adjuvant pertuzumab, trastuzumab, and docetaxel treatment in this patient population.

TH-4000, a hypoxia-activated pan-HER inhibitor, shows excellent preclinical efficacy for the treatment of HER2+ breast cancer.

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is correlated with poor prognosis, the current treatment of which is still based on surgery and adjuvant targeted therapy with monoclonal antibody. Problems of drug resistance hinder the use of monoclonal antibodies. Subsequently, tyrosine kinase inhibitors (TKIs) have been noticed, TKIs have the advantages of multi-targets and reduced drug resistance. However, TKIs that target HER family proteins often cause adverse effects such as liver damage and diarrhea. Thus, TKIs with high selectivity are being developed. TH-4000, a prodrug that generated an active form TH-4000Effector (TH-4000E) under hypoxic condition, was evaluated in this research. We found that TH-4000E ([(E)-4-[[4-(3-bromo-4-chloroanilino)pyrido[3,4-d]pyrimidin-6-yl]amino]-4-oxobut-2-enyl]-dimethyl-[(3-methyl-5-nitroimidazol-4-yl)methyl]azanium) (1-1000 nM) had potent and highly selective toxic effects on HER2+ breast cancer cells and inhibited the phosphorylation of HER family kinases at lower doses than that of Lapatinib and Tucatinib. TH-4000E activated Caspase-3 and induced apoptosis through a reactive oxygen species (ROS)-dependent pathway. The prodrug TH-4000 ([(E)-4-[[4-(3-bromo-4-chloroanilino)pyrido[3,4-d]pyrimidin-6-yl]amino]-4-oxobut-2-enyl]-dimethyl-[(3-methyl-5-nitroimidazol-4-yl)methyl]azanium;bromide) (50 mg/kg) effectively suppressed the tumor growth with less liver damage in mouse tumor models. This hypoxia-targeted strategy has possessed advantage in avoiding drug-induced liver damage, TH-4000 could be a promising drug candidate for the treatment of HER2+ breast cancer.

Axillary Nodal Response to Neoadjuvant T-DM1 Combined with Pertuzumab in a Prospective Phase II Multi-Institution Clinical Trial.

BACKGROUND: Patients with ERBB2 (HER2)-positive breast cancer experience high pathologic complete response (pCR) rates after standard neoadjuvant anti-HER2 systemic therapy. We examined axillary pathologic nodal response to neoadjuvant dual HER2-targeted therapy alone, based on breast pathologic response, in a multi-institution clinical trial. STUDY DESIGN: Patients with HER2-positive breast cancer were enrolled to a phase II single-arm trial, which administered 6 cycles of neoadjuvant trastuzumab emtansine (T-DM1) plus pertuzumab. Rates of pathologic nodal disease (ypN) in patients who were clinically node-negative (cN0) and node-positive (cN1) were analyzed, by residual breast disease (pCR and residual cancer burden [RCB] I to III). RESULTS: One hundred fifty-eight patients completed preoperative treatment and proceeded to surgery. Of 92 patients who were cN0, 48 (52.2%) and 10 (10.9%) experienced breast pCR and RCB I, respectively. Of these, 100% were ypN0. Of 34 with RCB II to III, 26 (76.5%) were ypN0. Of 30 patients who were cN1 with breast pCR, 100% were ypN0; of the 12 patients who were cN1 with RCB I, 66.7% were ypN0; and of the 24 patients who were cN1 with RCB II to III, 25% were ypN0. ypN0 rates were significantly different between patients who did and did not experience a pCR, in both cN0 (p = 0.002) and cN1 (p < 0.001) subgroups. CONCLUSIONS: Patients with HER2-positive breast cancer treated with dual HER2-targeted therapy who experienced a breast pCR or RCB I response were frequently ypN0. These findings support future trials considering omission of axillary surgical staging for patients with HER2-positive breast cancer in neoadjuvant trials of active HER2-targeted regimens, particularly if they experience breast pCR or RCB I.

Efficacy of Single-Agent Chemotherapy in Endocrine Therapy-Refractory Metastatic Invasive Lobular Carcinoma.

BACKGROUND: Hormone receptor (HR)-positive, HER2-negative metastatic invasive lobular breast cancer (mILC) is distinct from invasive ductal cancer (IDC) in clinicopathologic and molecular characteristics, impacting its response to systemic therapy. While endocrine therapy (ET) combined with targeted therapies has shown efficacy in ET-sensitive mILC, data on chemotherapy in ET-refractory mILC remain limited. We investigated the efficacy of single-agent capecitabine (CAP) versus taxanes (TAX) in ET-refractory HR+ HER2-negative patients with mILC. MATERIALS AND METHODS: Using data from the MD Anderson prospectively collected breast cancer database, we identified patients with HR+ HER2-negative mILC who received prior ET and first-time chemotherapy in the metastatic setting. We compared outcomes between 173 CAP-treated and 96 TAX-treated patients. RESULTS: CAP-treated patients had significantly better median progression-free survival (PFS) than TAX-treated patients (8.8 vs 5.0 months, HR 0.63, P < .001). Overall survival (OS) did not differ significantly between the groups (42.7 vs 36.6 months for CAP vs TAX, respectively, HR 0.84, P = .241). Multivariate analyses for PFS and OS revealed better outcomes in subjects with fewer metastatic sites and those exposed to more lines of ET. Additionally, Black patients showed worse OS outcomes compared to White patients (HR 2.46; P = .001). CONCLUSION: In ET-refractory HR+ HER2-negative mILC, single-agent CAP demonstrated superior PFS compared to TAX. Our findings highlight the potential benefit of CAP in this patient subset, warranting further investigation through prospective trials.

Circulating Tumor Cells Prediction in Hormone Receptor Positive HER2-Negative Advanced Breast Cancer: A Retrospective Analysis of the MONARCH 2 Trial.

BACKGROUND: The MONARCH 2 trial (NCT02107703) showed the efficacy of abemaciclib, a cyclin-dependent kinase 4 & 6 inhibitor (CDK4/6i), in combination with fulvestrant for hormone receptor-positive, HER2-negative metastatic breast cancer (MBC). The aim of this analysis was to explore the prediction of circulating tumor cells (CTCs) stratification using machine learning for hypothesis generation of biomarker-driven clinical trials. PATIENTS AND METHODS: Predicted CTCs were computed in the MONARCH 2 trial through a K nearest neighbor (KNN) classifier trained on a dataset comprising 2436 patients with MBC. Patients were categorized into predicted Stage IVaggressive (pStage IVaggressive, ≥5 predicted CTCs) or predicted Stage IVindolent (pStage IVindolent, <5 predicted CTCs). Prognosis was tested in terms of progression-free-survival (PFS) and overall survival (OS) through Cox regression. RESULTS: Patients classified as predicted pStage IVaggressive and predicted pStage Stage IVindolent were, respectively, 183 (28%) and 461 (72%). After multivariable Cox regression, predicted CTCs were confirmed as independently associated with prognosis in terms of OS, together with ECOG performance status, liver involvement, bone-only disease, and treatment arm. Patients in the pStage Stage IVindolent subgroup treated with abemaciclib experienced the best prognosis both in terms of PFS and OS. The treatment effect of abemaciclib on OS was then explored through subgroup analysis, showing a consistent benefit across all subgroups. CONCLUSION: This study is the first analysis of CTCs modeling for stage IV disease stratification. These results show the need to expand biomarker profiling in combination with CTCs stratification for improved biomarker-driven drug development.

Intrinsic Subtype and Overall Survival of Patients with Advanced HR+/HER2- Breast Cancer Treated with Ribociclib and ET: Correlative Analysis of MONALEESA-2, -3, -7.

PURPOSE: The MONALEESA-2, -3, -7 trials demonstrated statistically significant and clinically meaningful progression-free survival and overall survival (OS) benefits with ribociclib plus endocrine therapy (ET) versus ET alone in hormone receptor-positive, HER2-negative (HR+/HER2-) advanced breast cancer (ABC). Understanding the association of intrinsic subtypes with survival outcomes could potentially guide treatment decisions. Here, we evaluated the association of intrinsic subtypes with OS in MONALEESA-2, -3, -7. EXPERIMENTAL DESIGN: Tumor samples from MONALEESA-2, -3, -7 underwent PAM50-based subtyping. The relationship between subtypes and OS was assessed using univariable and multivariable Cox proportional hazards models. Multivariable models were adjusted for clinical prognostic factors. RESULTS: Overall, 990 tumors (among 2,066 patients) from ribociclib (n = 580) and placebo (n = 410) arms were profiled. Subtype distribution was luminal A, 54.5%; luminal B, 28.0%; HER2-enriched (HER2E) 14.6%; and basal-like, 2.8%; and was consistent across treatment arms. The luminal A subtype had the best OS outcomes in both arms, while basal-like had the worst. Patients with HER2E (HR, 0.60; P = 0.018), luminal B (HR, 0.69; P = 0.023), and luminal A (HR, 0.75; P = 0.021) subtypes derived OS benefit with ribociclib. Patients with basal-like subtype did not derive benefit from ribociclib (HR, 1.92; P = 0.137); however, patient numbers were small (n = 28). CONCLUSIONS: The prognostic value of intrinsic subtypes for OS was confirmed in this pooled analysis of the MONALEESA trials (largest dataset in HR+/HER2- ABC). While basal-like subtype did not benefit, a consistent OS benefit was observed with ribociclib added to ET across luminal and HER2E subtypes.

Overall Survival and Exploratory Biomarker Analyses of Abemaciclib plus Trastuzumab with or without Fulvestrant versus Trastuzumab plus Chemotherapy in HR+, HER2+ Metastatic Breast Cancer Patients.

PURPOSE: The monarcHER trial has shown that abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, combined with fulvestrant and trastuzumab, improves progression-free survival (PFS) in hormone receptor-positive (HR+), HER2-positive (HER2+) advanced breast cancer (ABC) compared with standard-of-care (SOC) chemotherapy combined with trastuzumab. We report the final overall survival (OS) analysis, updated safety and efficacy data, and exploratory biomarker results from monarcHER. PATIENTS AND METHODS: monarcHER (NCT02675231), a randomized, multicenter, open-label, phase II trial, enrolled 237 patients across Arm A (abemaciclib, trastuzumab, fulvestrant), Arm B (abemaciclib, trastuzumab), and Arm C (SOC chemotherapy, trastuzumab). Following the statistical plan, OS and PFS were estimated in all arms. RNA sequencing (RNA-seq) was performed on archival tissue. RESULTS: Median OS was 31.1 months in Arm A, 29.2 months in Arm B, and 20.7 months in Arm C [A vs. C: HR, 0.71; 95% confidence interval (CI), 0.48-1.05; nominal two-sided P value 0.086; B vs. C: HR 0.83 (95% CI, 0.57-1.23); nominal two-sided P value 0.365]. Updated PFS and safety findings were consistent with previous results. The most frequently reported treatment-emergent adverse events included diarrhea, fatigue, nausea, neutrophil count decrease, and anemia. In exploratory RNA-seq analyses, Luminal subtypes were associated with longer PFS [8.6 vs. 5.4 months (HR, 0.54; 95% CI, 0.38-0.79)] and OS [31.7 vs. 19.7 months (HR, 0.68; 95% CI, 0.46-1.00)] compared with non-Luminal. CONCLUSIONS: In this phase II trial, abemaciclib + trastuzumab ± fulvestrant numerically improved median OS in women with HR+, HER2+ ABC compared with SOC chemotherapy + trastuzumab.

Long-Term Outcomes and Predictors of Response in Breast Cancer Patients with Advanced Nodal Involvement.

BACKGROUND: Advanced nodal disease is associated with poor prognosis. However, modern neoadjuvant systemic therapy (NST) regimens have resulted in higher pathologic complete response (pCR) rates, which are associated with improved survival. We sought to assess contemporary outcomes in patients with advanced nodal involvement and response to NST. STUDY DESIGN: We conducted a single-institution, retrospective study of 521 patients with cN2-3 primary nonmetastatic breast cancer treated with NST followed by surgery and radiation from 2012 to 2018. Descriptive statistics, multivariate Cox regression, and Kaplan-Meier analyses were performed. RESULTS: The mean age was 50.5 years, and median follow-up was 61 (4.7 to 197) months. The majority of patients had hormone receptor-positive (HR+)/HER2-negative tumors (HER2-; n = 242, 47.8%). Most were cT2 (n = 243; 46.6%) or cT3 (n = 139; 26.7%) and 73.3% (n = 382) had cN3 disease. Rate of axillary pCR was 34.2%, and breast and axillary pCR was 19.4% (n = 101). Event-free survival (EFS) at 5 years was 75.1% (95% CI, 0.71 to 0.79). Rate of locoregional recurrence was 6.7%; distant metastatic rate was 29.4%. Axillary pCR with or without breast pCR was significantly associated with longer EFS (p = 0.001). Achieving breast/axillary pCR was an independent predictor of improved EFS (hazard ratio 0.22, p < 0.0001). Having triple-negative disease was associated with worse EFS (hazard ratio 1.74, p = 0.008). CONCLUSIONS: In a high-risk cohort of patients with cN2-3 disease, trimodality therapy was effective in achieving durable EFS. Approximately one-third of patients achieved axillary pCR, which was associated with improved survival. Further studies are needed to accurately determine axillary response in cN2-3 breast cancer after NST in order to develop de-escalation strategies to reduce morbidity associated with axillary surgery.

Convenient determination of serum HER-2 status in breast cancer patients using Raman spectroscopy.

Given the significant therapeutic efficacy of anti-HER-2 treatment, the HER-2 status is a crucial piece of information that must be obtained in breast cancer patients. Currently, as per guidelines, HER-2 status is typically acquired from breast tissue of patients. However, there is growing interest in obtaining HER-2 status from serum and other samples due to the convenience and potential for dynamic monitoring. In this study, we have developed a serum Raman spectroscopy technique that allows for the rapid acquisition of HER-2 status in a convenient manner. The established HER-2 negative and positive classification model achieved an area under the curve of 0.8334. To further validate the reliability of our method, we replicated the process using immunohistochemistry and in situ hybridization. The results demonstrate that serum Raman spectroscopy, coupled with artificial intelligence algorithms, is an effective technical approach for obtaining HER-2 status.

A Phase II Study of Neoadjuvant PLD/Cyclophosphamide and Sequential nab-Paclitaxel Plus Dual HER2 Blockade in HER2-Positive Breast Cancer.

BACKGROUND: Neoadjuvant trastuzumab/pertuzumab (HP) plus chemotherapy for HER2-positive breast cancer (BC) achieved promising efficacy. The additional cardiotoxicity still existed. Brecan study evaluated the efficacy and safety of neoadjuvant pegylated liposomal doxorubicin (PLD)/cyclophosphamide and sequential nab-paclitaxel based on HP (PLD/C/HP-nabP/HP). PATIENTS AND METHODS: Brecan was a single-arm phase II study. Eligible patients with stages IIA-IIIC HER2-positive BC received 4 cycles of PLD, cyclophosphamide, and HP, followed by 4 cycles of nab-paclitaxel and HP. Definitive surgery was scheduled after 21 days for patients completing treatment or experiencing intolerable toxicity. The primary endpoint was the pathological complete response (pCR). RESULTS: Between January 2020 and December 2021, 96 patients were enrolled. Ninety-five (99.0%) patients received 8 cycles of neoadjuvant therapy and all underwent surgery with 45 (46.9%) breast-conserving surgery and 51 (53.1%) mastectomy. The pCR was 80.2% (95%CI, 71.2%-87.0%). Four (4.2%) experienced left ventricular insufficiency with an absolute decline in LVEF (43%-49%). No congestive heart failure and ≥grade 3 cardiac toxicity occurred. The objective response rate was 85.4% (95%CI, 77.0%-91.1%), including 57 (59.4%) complete responses and 25 (26.0%) partial responses. The disease control rate was 99.0% (95%CI, 94.3%-99.8%). For overall safety, ≥grade 3 AEs occurred in 30 (31.3%) and mainly included neutropenia (30.2%) and asthenia (8.3%). No treatment-related deaths occurred. Notably, age of >30 (P = .01; OR = 5.086; 95%CI, 1.44-17.965) and HER2 IHC 3+ (P = .02; OR = 4.398; 95%CI, 1.286-15.002) were independent predictors for superior pCR (ClinicalTrials.gov Identifier NCT05346107). CONCLUSION: Brecan study demonstrated the encouraging safety and efficacy of neoadjuvant PLD/C/HP-nabP/HP, suggesting a potential therapeutic option in HER2-positive BC.

Phase Ia/b Study of Giredestrant ± Palbociclib and ± Luteinizing Hormone-Releasing Hormone Agonists in Estrogen Receptor-Positive, HER2-Negative, Locally Advanced/Metastatic Breast Cancer.

PURPOSE: Giredestrant is an investigational next-generation, oral, selective estrogen receptor antagonist and degrader for the treatment of estrogen receptor-positive (ER+) breast cancer. We present the primary analysis results of the phase Ia/b GO39932 study (NCT03332797). PATIENTS AND METHODS: Patients with ER+, HER2-negative locally advanced/metastatic breast cancer previously treated with endocrine therapy received single-agent giredestrant (10, 30, 90, or 250 mg), or giredestrant (100 mg) ± palbociclib 125 mg ± luteinizing hormone-releasing hormone (LHRH) agonist. Detailed cardiovascular assessment was conducted with giredestrant 100 mg. Endpoints included safety (primary), pharmacokinetics, pharmacodynamics, and efficacy. RESULTS: As of January 28, 2021, with 175 patients enrolled, no dose-limiting toxicity was observed, and the MTD was not reached. Adverse events (AE) related to giredestrant occurred in 64.9% and 59.4% of patients in the single-agent ± LHRH agonist and giredestrant + palbociclib ± LHRH agonist cohorts, respectively (giredestrant-only-related grade 3/4 AEs were reported in 4.5% of patients across the single-agent cohorts and 3.1% of those with giredestrant + palbociclib). Dose-dependent asymptomatic bradycardia was observed, but no clinically significant changes in cardiac-related outcomes: heart rate, blood pressure, or exercise duration. Clinical benefit was observed in all cohorts (48.6% of patients in the single-agent cohort and 81.3% in the giredestrant + palbociclib ± LHRH agonist cohort), with no clear dose relationship, including in patients with ESR1-mutated tumors. CONCLUSIONS: Giredestrant was well tolerated and clinically active in patients who progressed on prior endocrine therapy. Results warrant further evaluation of giredestrant in randomized trials in early- and late-stage ER+ breast cancer.

Current Management and Future Perspectives in Metastatic HER2-Positive Breast Cancer.

OBJECTIVE: Metastatic HER2-positive breast cancer remains a significant clinical challenge with a poor prognosis. The introduction of anti-HER2 therapies has significantly improved survival in early and advanced stages. However, patients with metastatic HER2-positive breast cancer eventually experience progression due to de novo or acquired resistance. This review article comprehensively analyzes the current management of metastatic HER2-positive breast cancer, addressing the complexities in determining the optimal HER2-targeted therapy sequence. DATA SOURCES: Discussion of selected peer-reviewed articles and expert opinion. CONCLUSIONS: We explore the actual standard of care and the emerging therapeutic options that hold promise for further improving patient care and survival in this aggressive breast cancer subtype. This article highlights vital toxicities linked to anti-HER2 therapies, emphasizing their recognition across treatments as interstitial lung disease, diarrhea, or left ventricular dysfunction. IMPLICATIONS FOR NURSING PRACTICES: Oncology nurses have a key role to play in detecting potential adverse effects of anti-HER2 therapies. The development of new drugs, as antibody-drug conjugates, with a distinct toxicity profile makes it necessary for us to be updated on the management of these new toxicities.

Cardiovascular sequelae of trastuzumab and anthracycline in long-term survivors of breast cancer.

OBJECTIVES: Long-term follow-up of patients treated with trastuzumab largely focuses on those with reduced left ventricular ejection fraction (LVEF) on treatment completion. This study sought to evaluate the prevalence of cardiovascular risk factors, overt cardiovascular disease and cardiac imaging abnormalities using cardiac magnetic resonance (CMR), in participants with normal LVEF on completion of trastuzumab±anthracycline therapy at least 5 years previously. METHODS: Participants with human epidermal growth factor receptor 2-positive breast cancer treated with trastuzumab±anthracycline ≥5 years previously were identified from a clinical database. All participants had normal LVEF prior to, and on completion of, treatment. Participants underwent clinical cardiovascular evaluation, ECG, cardiac biomarker evaluation and CMR. Left ventricular systolic dysfunction (LVSD) was defined as LVEF <50%. RESULTS: Forty participants were recruited between 15 March 2021 and 19 July 2022. Median time since completion of trastuzumab was 7.8 years (range 5.9-10.8 years) and 90% received prior anthracycline. 25% of participants had LVSD; median LVEF was 55.2% (Q1-Q3, 51.3-61.2). 30% of participants had N-terminal pro-B-type natriuretic peptide >125 pg/mL and 8% had high-sensitivity cardiac troponin T >14 ng/L. 33% of participants had a new finding of hypertension. 58% had total cholesterol >5.0 mmol/L, 43% had triglycerides >1.7 mmol/L and 5% had a new diagnosis of diabetes. CONCLUSIONS: The presence of asymptomatic LVSD, abnormal cardiac biomarkers and cardiac risk factors in participants treated with trastuzumab and anthracycline at least 5 years previously is common, even in those with normal LVEF on completion of treatment. Our findings reinforce the relevance of comprehensive evaluation of cardiovascular risk factors following completion of cancer therapy, in addition to LVEF assessment.

Toxic Cardiomyopathy in a Young Patient Treated for Her2-Positive Early Breast Cancer: Case Report and Literature Review.

OBJECTIVE: We present the case of toxic cardiomyopathy in a healthy thirty-eight-year-old female patient treated for Her2-positive early breast cancer. CASE REPORT: During the neoadjuvant treatment, the patient received four cycles of AC regimen and four cycles of docetaxel in combination with trastuzumab biosimilar. Two days after she received the ninth dose of trastuzumab biosimilar, she reported feebleness, palpitation, and dyspnoea. A heart ultrasound was performed and was normal without changes in the ejection fraction (EF) compared to previous checks. Three days later she reports worsening of her symptoms that were highly suggestive of heart failure. A cardiologist was consulted who insisted that the patient's symptoms were the consequence of the disease progression. A CT scan showed signs of heart failure. A heart ultrasound was done and the EF dropped to 30%. Drainage of the right pleural cavity was performed and pharmacotherapy for heart failure was started. The treatment led to clinical improvement, but eighteen months later EF is still not back to normal. CONCLUSION: This is a rare case of toxic cardiomyopathy in a young, previously healthy, patient who received anthracyclines followed by trastuzumab biosimilar in combination with taxanes. All the medications this patient received are potentially cardiotoxic. However, the overall presentation is not typical for any of these medications since the patient presented with symptoms and signs of heart failure with significant dilatation of the right atrium, which persists eighteen months after its onset, with only a small increase in the EF. There is also a possibility that the antineoplastic therapy the patient received only facilitated dilatative cardiomyopathy, while the main causative factor was intrinsic or extrinsic.

Pyrotinib plus docetaxel as first-line treatment for HER2-positive metastatic breast cancer: the PANDORA phase II trial.

The role of pyrotinib in the treatment of HER2-positive metastatic breast cancer (MBC) has been well-established. This multicenter, single-arm phase II trial (NCT03876587) aimed to assess the benefit of pyrotinib plus docetaxel as a first-line treatment for HER2-positive MBC. Women with HER2-positive MBC who had not undergone HER2 blockade or chemotherapy for metastatic disease were enrolled in the study and received daily oral pyrotinib 400 mg plus intravenous docetaxel 75 mg/m2 every 3 weeks. The primary endpoint was the objective response rate (ORR), secondary endpoints included progression-free survival (PFS), duration of response (DoR), clinical benefit rate (CBR), overall survival (OS) and safety. From June 2019 to June 2021, 79 patients were enrolled. The confirmed ORR was 79.7% (95% confidence interval [CI], 70.8-88.6), and the CBR was 87.3% (95%CI, 80.0-94.6) in the intention-to-treat population. The pre-specified primary endpoint was met. The median DoR was 15.9 months (interquartile range, 8.3-19.5); the median PFS was 16.0 months (95% CI, 11.2-20.8), and the median OS was not reached. The most common grade ≥3 treatment-related adverse events observed were leukopenia (29.1%), neutropenia (27.8%), and diarrhea (21.5%). This study demonstrates that pyrotinib plus docetaxel show an acceptable safety profile and promising antitumor activity as a first-line treatment option for patients with HER2-positive MBC.

Third-line treatment patterns in HER2-positive metastatic breast cancer: a retrospective analysis of real-world data in Canada.

There is an increasing demand for real-world data pertaining to the usage of cancer treatments, especially in settings where no standard treatment is specifically recommended. This study presents the first real-world analysis of third-line treatment patterns in HER2-positive metastatic breast cancer (mBC) patients in Canada. The purpose was to assess evolution of clinical practice and identify unmet needs in post-second-line therapy. Retrospective data from medical records of 66 patients who received third-line treatment before 31st October 2018, and data from 56 patients who received third-line treatment after this date, extracted from the Personalize My Treatment (PMT) cancer patient registry, were analyzed. In the first cohort, the study revealed heterogeneity in the third-line setting, with trastuzumab, lapatinib, and T-DM1 being the main treatment options. Even though data were collected before the wide availability of tucatinib, neratinib and trastuzumab deruxtecan in Canada, the PMT cohort revealed the emergence of new therapeutic combinations and a shift from lapatinib usage to T-DM1 choice was observed. These findings underscore the evolving nature of third-line treatment strategies in Canada, a facet that is intrinsically tied to the availability of new drugs. The absence of a consensus on post-second-line treatment highlights the pressing need for more efficient therapeutic alternatives beyond the currently available options. This study not only offers valuable insights into the present landscape of third-line treatment in Canada but validates the significance and effectiveness of the PMT registry as a tool for generating pan-Canadian real-world evidence in oncology and its capacity to provide information on evolution of therapeutic practices.

Immunological and clinicopathological features predict HER2-positive breast cancer prognosis in the neoadjuvant NeoALTTO and CALGB 40601 randomized trials.

The identification of prognostic markers in patients receiving neoadjuvant therapy is crucial for treatment optimization in HER2-positive breast cancer, with the immune microenvironment being a key factor. Here, we investigate the complexity of B and T cell receptor (BCR and TCR) repertoires in the context of two phase III trials, NeoALTTO and CALGB 40601, evaluating neoadjuvant paclitaxel with trastuzumab and/or lapatinib in women with HER2-positive breast cancer. BCR features, particularly the number of reads and clones, evenness and Gini index, are heterogeneous according to hormone receptor status and PAM50 subtypes. Moreover, BCR measures describing clonal expansion, namely evenness and Gini index, are independent prognostic factors. We present a model developed in NeoALTTO and validated in CALGB 40601 that can predict event-free survival (EFS) by integrating hormone receptor and clinical nodal status, breast pathological complete response (pCR), stromal tumor-infiltrating lymphocyte levels (%) and BCR repertoire evenness. A prognostic score derived from the model and including those variables, HER2-EveNT, allows the identification of patients with 5-year EFS > 90%, and, in those not achieving pCR, of a subgroup of immune-enriched tumors with an excellent outcome despite residual disease.

Comparative Evaluation of Biosimilar Trastuzumab with Reference Trastuzumab Activity in HER2-Positive Breast Cancer Patients.

One of the breast cancer subtypes, epidermal growth factor receptor 2 (HER2), accounts for 15% of all breast cancers and is characterized by aggressive behavior and a poor prognosis. For patients with HER2-positive breast cancer, trastuzumab, a monoclonal antibody that targets HER2 receptors, is prescribed in addition to chemotherapy to increase their chances of survival. However, the high expense of this treatment makes it impossible for patients in developing nations to easily afford it and undergo this biological therapy. Consequently, trastuzumab biosimilars have been launched as a substitute that offers comparable effectiveness at a reduced price. This study aimed to compare the biological activity and cardiac safety of reference trastuzumab with biosimilar trastuzumab by monitoring serum levels of the tumor biomarker CA15-3 and evaluating N-terminal pro-B-type natriuretic peptide (NT-proBNP) for the adverse cardiac effects of both treatments on HER2-positive breast cancer patients before and after six cycles of biological therapy. This prospective research was performed on 36 females with metastatic and early-stage HER2-positive breast cancer who visited the Oncology Department at Rizgary Hospital, Erbil, Iraq. The patients were within the age range of 30-80 years old. Eighteen individuals received reference trastuzumab, while the remaining 18 received both chemotherapy and biosimilar trastuzumab. Each patient had a data sheet that contained details from hospital-reserved files. In the Herceptin group, there was an insignificant difference in the median of CA15-3, while no significant difference was detected between the means of NT-proBNP before and after treatment. In the biosimilar group, there was a significant reduction in the median CA15-3 as well as a significant increase in the level of NT-proBNP before and after the treatment. Evaluation of the association of trastuzumab-induced cardiotoxicity during breast cancer treatment with different factors indicated that there might be an increased risk of cardiotoxicity after trastuzumab treatment.