Dual HER2 Blockade in Neoadjuvant Treatment of HER2+ Breast Cancer: A Meta-Analysis and Review

Exploring the Combined Action of Adding Pertuzumab to Branded Trastuzumab versus Trastuzumab Biosimilars for Treating HER2+ Breast Cancer

The binding activity of various trastuzumab biosimilars versus the branded trastuzumab towards the glycosylated extracellular domain of the human epidermal growth factor receptor 2 (HER2) target in the presence of pertuzumab was investigated. We employed size exclusion chromatography with tetra-detection methodology to simultaneously determine absolute molecular weight, concentration, molecular size, and intrinsic viscosity. All trastuzumab molecules in solution exhibit analogous behavior in their binary action towards HER2 regardless of the order of addition of trastuzumab/pertuzumab. This analogous behavior of all trastuzumab molecules, including biosimilars, highlights the robustness and consistency of their binding activity towards HER2. Furthermore, the addition of HER2 to a mixture of trastuzumab and pertuzumab leads to increased formation of high-order HER2 complexes, up to concentrations of one order of magnitude higher than in the case of sequential addition. The observed increase suggests a potential synergistic effect between these antibodies, which could enhance their therapeutic efficacy in HER2-positive cancers. These findings underscore the importance of understanding the complex interplay between therapeutic antibodies and their target antigens, providing valuable insights for the development of more effective treatment strategies.

Short-term efficacy and safety of neoadjuvant pyrotinib plus taxanes for early HER2-positive breast cancer: a single-arm exploratory phase II trial

Background

The effectiveness and safety of pyrotinib have been substantiated in human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (BC). However, the role of pyrotinib as a single HER2 blockade in neoadjuvant setting among BC patients has not been studied. The objective of this study was to evaluate the efficacy and tolerability of pyrotinib plus taxanes as a novel neoadjuvant regimen in patients with HER2-positive early or locally advanced BC.

Methods

In this single-arm exploratory phase II trial, patients with treatment-naïve HER2-positive BC (stage IIA-IIIC) received pyrotinib 400 mg once daily and taxanes [docetaxel 75 mg/m2 or nanoparticle albumin-bound (nab)-paclitaxel 260 mg/m2 every 3 weeks, or paclitaxel 80 mg/m2 weekly] for a total of four 21-day cycles before surgery. Efficacy assessment was based on pathological and clinical measurements. The primary endpoint of this study was the total pathological complete response (tpCR) rate. The secondary endpoints included breast pCR (bpCR) rate, investigator-assessed objective response rate (ORR) and adverse events (AEs) profiles.

Results

From 1 September 2021 to 30 December 2022, a total of 31 patients were enrolled. One patient was withdrawn due to unbearable skin rash after the second cycle of neoadjuvant therapy. The majority of the intention-to-treat (ITT) population was premenopausal (54.8%), had large tumors (90.3%) and metastatic nodes (58.1%) at diagnosis and hormone-receptor positive tumors (64.5%). Most participants used nab-paclitaxel (74.2%) and received mastectomy (67.7%) after neoadjuvant treatment. The tpCR and bpCR rates were 48.4% [95% confidence interval (CI): 30.8-66%] and 51.6% (95% CI: 34-69.2%), respectively. Grade ≥3 treatment-related AEs were observed in 16.1% (5/31) of the ITT population, including diarrhea (n=2, 6.5%), hand and foot numbness (n=1, 3.2%), loss of appetite (n=1, 3.2%), and skin rash (n=1, 3.2%). AE related dose reduction or pyrotinib interruption was not required.

Conclusions

In female patients with HER2-positive non-metastatic BC, neoadjuvant pyrotinib monotherapy plus taxanes appears to show promising clinical benefit and controllable AEs [Chinese Clinical Trial Registry (ChiCTR2100050870)]. The long-term efficacy and safety of this regime warrant further verification.

Therapeutic Approaches to Increase the Survival Rate of Cancer Patients in the Younger and Older Population

Various developments have been observed in the treatment of cancer patients, such as higher survival rates and better treatment outcomes. However, expecting similar outcomes in older patients remains a challenge. The main reason for this conclusion is the exclusion of older people from clinical trials for cancer drugs, as well as other factors, such as comorbidity, side effects, age-related frailties and their willingness to undergo multiple treatments. However, the discovery of new techniques and drug combinations has led to a significant improvement in the survival of the elderly population after the onset of the disease. On the other hand, cancer treatments have not become more complex for the younger population when compared to the older population, as the younger population tends to respond well to treatment trials and their physiological conditions are stable in response to treatments. In summary, this review correlates recent cancer treatment strategies and the corresponding responses and survival outcomes of older and younger patients.

Guidelines for breast cancer management in Bosnia and Herzegovina

Breast cancer is the most common cancer among women. In Bosnia and Herzegovina, accurate data on the status of breast cancer are lacking due to the absence of a central registry. Multiple international guidelines imply that institutions that monitor breast cancer patients should have optimal therapeutic options for treatment. In addition, there have been several international consensus guidelines written on the management of breast cancer. Application of consensus guidelines has previously been demonstrated to have a positive influence on breast cancer care. The importance of specialty breast centers has previously been reported. As part of the 2021 Bosnian-Herzegovinian American Academy of Arts and Sciences (BHAAAS) conference in Mostar, a round table of multidisciplinary specialists from Bosnia and Herzegovina and the diaspora was held. All were either members of BHAAAS or regularly participate in collaborative projects. The focus of the consortium was to write the first multidisciplinary guidelines for the general management of breast cancer in Bosnia and Herzegovina. Guidelines were developed for each area of breast cancer treatment and management. These guidelines will serve as a resource for practitioners managing breast cancer in the Bosnia and Herzegovina region. This might also be of benefit to the ministry of health and any future investors interested in developing breast cancer care policies in this region of the world.

Relationship between pathological response and molecular subtypes in locally advanced breast cancer patients receiving neoadjuvant chemotherapy

Majority of patients with breast cancer were diagnosed with locally advanced stages of the disease (54%). This study aimed to explain the pathological response received to neoadjuvant chemotherapy (NACT) according to the molecular classification of breast cancer in patients with locally advanced tumors. One hundred and one patients with locally advanced breast cancer treated with neoadjuvant chemotherapy were analyzed. Patients were classified into five molecular subtypes based on the profile of the estrogen receptor, progesterone receptor, HER2, and Ki-67. We determined associations between complete pathological response (no invasive tumor after neoadjuvant chemotherapy) and molecular subgroups. Most patients had luminal A tumors (n: 28, 27.7%). The overall rate of complete pathological response (pCR) was 34.7% (n:35). Tumors that presented with the highest rate of pCR were pure HER2-positive, at 60% (n:6; OR, 3.2; 95% CI, 0.8-12.2). According to logistic regression analysis, the factors affecting pCR were HER2 positivity and clinically positive axilla before NACT. Luminal A tumors had a significantly lower pCR rate. (7.1%,p: 0.001). Despite the low pCR rate, Luminal A tumor had the best survival rate in the subgroups (p < 0.001). However, there was no difference between EFS and OS according to pCR in any molecular subgroups. Pathological complete response is directly related to the subtypes of breast cancer. A high complete pathological response rate is observed in the pure HER2-positive group. However, EFS and OS were not statistically significant in patients with and without pCR.

Axillary Downstaging and the Impact of Clinical Axillary Status on Efficacy of Neoadjuvant Therapy for HER2-Positive Breast Cancer: A Network Meta-Analysis

Background: Lymph node downstaging and the achievement of total-pCR (ypT0/is ypN0) after neoadjuvant therapy are of great importance in HER-2 positive breast cancer. We aim to provide an overall review of neoadjuvant regimens for lymph node downstaging and to indirectly compare the total-pCR by various neoadjuvant regimens with network meta-analysis in HER2-positive patients according to their clinical lymph node status. Methods: Five English databases were searched comprehensively and systematically for relevant RCTs and case-control studies. The data extracted from the included studies were analyzed with the use of Review Manager 5.3 or STATA 15.0 software. Results: A total of 1508 published manuscripts were identified, and 17 studies including 4747 patients were finally included in our analysis. The network meta-analysis of total-pCR showed that dual-target therapy is significantly better than single-target therapy in clinically node-positive patients, and carboplatin performed significantly better than anthracycline in single-target condition. Lapatinib performed poorly in clinically node-positive patients. However, lapatinib in combination with trastuzumab was ranked at the top in the clinically node-negative group, and pertuzumab showed dissatisfied performance in contrast to the primacy of pertuzumab in clinically node-positive groups. Conclusion: In summary, different lymph node statuses led to the diverse first choice of neoadjuvant regimen. We highly recommended TCbHP as the first choice for the neoadjuvant treatment in clinically node-positive HER-2 positive breast cancer. Since lapatinib with trastuzumab ranked top in the clinically node-negative group, we looked forward to discovering the potential value of TKI in clinically node-negative patients, which needs further analysis in the future.

Pertuzumab combined with trastuzumab compared to trastuzumab in the treatment of HER2-positive breast cancer: A systematic review and meta-analysis of randomized controlled trials

Objective

Although dual anti-HER2 therapy, namely, pertuzumab plus trastuzumab, has shown promising results in patients with HER2-positive breast cancer (BC), it is still unclear whether dual therapy will increase adverse effects (AEs) while ensuring the efficacy compared with trastuzumab monotherapy. We conducted a systematic review and meta-analysis to compare the efficacy and safety of combined therapy with monotherapy.

Methods

A systematic search was performed to identify eligible randomized controlled trials (RCTs) that evaluated the administration of dual anti-HER2 therapy [pertuzumab plus trastuzumab or trastuzumab emtansine (T-DM1)] versus monotherapy (trastuzumab or T-DM1). The primary endpoints were overall survival (OS) and progression-free survival (PFS).

Results

Fourteen RCTs (8,378 patients) were identified. Compared to monotherapy, dual therapy significantly improved the OS (HR = 0.77, 95% CI: 0.59–0.99) and PFS (HR = 0.74, 95% CI: 0.63–0.86) in advanced BC. In neoadjuvant therapy, dual blockade has a higher ORR rate than monotherapy. Grade 3 or higher febrile neutropenia, diarrhea, and anemia as well as heart failure were more frequently reported in dual therapy compared to monotherapy. No significant difference in serious AEs was observed between the two groups. In the subgroup analysis, compared to single-target therapy, dual-target therapy has higher OS and PFS rates in Asian patients with advanced therapy; however, total grade ≥3 AEs and serious AEs were significantly higher in the dual group in Asian patients.

Conclusions

Our study confirms that the combination of pertuzumab and trastuzumab therapy could substantially improve the outcome of patients with HER2-positive breast cancer and was well tolerated compared to trastuzumab monotherapy.

Primary Chemoradiotherapy Treatment (PCRT) for HER2+ and Triple Negative Breast Cancer Patients: A Feasible Combination

Primary systemic treatment (PST) downsizes the tumor and improves pathological response. The aim of this study is to analyze the feasibility and tolerance of primary concurrent radio−chemotherapy (PCRT) in breast cancer patients. Patients with localized TN/HER2+ tumors were enrolled in this prospective study. Radiation was delivered concomitantly during the first 3 weeks of chemotherapy, and it was based on a 15 fractions scheme, 40.5 Gy/2.7 Gy per fraction to whole breast and nodal levels I-IV. Chemotherapy (CT) was based on Pertuzumab−Trastuzumab−Paclitaxel followed by anthracyclines in HER2+ and CBDCA-Paclitaxel followed by anthracyclines in TN breast cancers patients. A total of 58 patients were enrolled; 25 patients (43%) were TN and 33 patients HER2+ (57%). With a median follow-up of 24.2 months, 56 patients completed PCRT and surgery. A total of 35 patients (87.5%) achieved >90% loss of invasive carcinoma cells in the surgical specimen. The 70.8% and the 53.1% of patients with TN and HER-2+ subtype, respectively, achieved complete pathological response (pCR). This is the first study of concurrent neoadjuvant treatment in breast cancer in which three strategies were applied simultaneously: fractionation of RT (radiotherapy) in 15 sessions, adjustment of CT to tumor phenotype and local planning by PET. The pCR rates are encouraging.

Neoadjuvant Efficacy of Three Targeted Therapy Strategies for HER2-Positive Breast Cancer Based on the Same Chemotherapy Regimen

(1) Background: The objective of our study was to provide evidence for choosing the optimal neoadjuvant therapy strategies for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. Three neoadjuvant targeted therapy strategies (H + Py, trastuzumab plus pyrotinib; H, trastuzumab; HP, trastuzumab plus pertuzumab) based on the same chemotherapy regimen (TC, docetaxel and carboplatin) were included in the present study; (2) Methods: We retrospectively analyzed patients with HER2-positive breast cancer who were treated with neoadjuvant TCH + Py, TCH or TCHP, followed by surgery. The outcome was the pathological complete response (pCR) rate; (3) Results: In total, 545 patients were enrolled. The pCR rate was 55.6% (35/63) in the TCH + Py cohort, 32.7% (93/284) in the TCH cohort, and 56.6% (112/198) in the TCHP cohort. The multivariate analysis showed that patients who received TCH had less possibility to achieve pCR than those who received TCH + Py (odds ratio (OR) = 0.334, 95% confidence interval (CI): 0.181−0.619, p < 0.001), while patients who received TCHP had comparable possibility to those who received TCH + Py (OR = 1.043, 95%CI: 0.554−1.964, p = 0.896); (4) Conclusions: TCH + Py provides a better pCR rate compared with TCH, and a comparable pCR rate with TCHP among patients with HER2-positive breast cancer in the neoadjuvant setting. The present study supports a novel potential treatment option for these patients. Further studies need to be explored in the future.

Treatment of small (T1mic, T1a, and T1b) node-negative HER2+ breast cancer - a review of current evidence for and against the use of anti-HER2 treatment regimens

INTRODUCTION

Since the advent of anti-HER2 therapies, evidence surrounding adjuvant treatment of small (T1mic, T1a, and T1b), node-negative, HER2-positive breast cancer (HER2+BC) has remained limited. Practices vary widely between institutions with little known regarding the added benefit of systemic therapy, including cytotoxic chemotherapy and HER2-directed treatments. Our group has set out to perform an extensive review of available literature on this topic.

AREAS COVERED

In this review, we examined HER2 biology, anti-HER therapies, outcome definitions, and available prospective and retrospective data surrounding the use of adjuvant therapy in those with small, node-negative, HER2+BC. For outcomes, we primarily explored breast cancer-specific survival (BCSS), invasive disease-free survival (iDFS), and overall survival (OS). We also investigated the incidence of adverse events with a particular focus on symptomatic and asymptomatic declines in left ventricular ejection fraction.

EXPERT OPINION

Retrospective data will likely be the main driver for future treatment decisions. Given what we know, high risk T1b and T1c subgroups derive measurable added benefit from HER2-guided combination therapies but it's not clear whether these benefits outweigh known risks associated with this combination therapy. For tumors ≤0.5cm (T1mic and T1a), treatment remains highly controversial with limited evidence available through retrospective analysis that suggest over-treatment may be occurring.