Systemic Therapy for HER2-Positive Metastatic Breast Cancer: Current and Future Trends

Targeting mitochondrial dynamics emerges as an effective strategy of cardioprotection against trastuzumab-induced mitochondrial functional aberrations and cardiotoxicity in rats

Trastuzumab (Trz) is a targeted anticancer therapy that specifically acts on tumors overexpressing the human epidermal growth factor receptor 2 (HER2) protein. Previous research has shown that Trz can induce cardiotoxicity by altering mitochondrial function. While modulating mitochondrial dynamics with Mdivi-1 and M1 has shown cardioprotective effects in various cardiac conditions, their impact on Trz-induced cardiotoxicity in rats remains unclear. In this study, thirty-two male Wistar rats were divided into a control group (CON, n = 8) and a Trz-treated group (4 mg/kg/day, i.p. for 7 days, n = 24). The Trz group was further randomized into subgroups receiving either: 1) vehicle (VEH, 3 % DMSO, i.p., n = 8), 2) the mitochondrial fission inhibitor Mdivi-1 (MDV, 1.2 mg/kg/day, i.p., n = 8), or 3) the mitochondrial fusion promoter M1 (2 mg/kg/day, i.p., n = 8). All interventions began on the first day of Trz administration and continued for 7 days. At the end, cardiac function was then assessed, and heart tissue was collected for biochemical analysis. Trz-treated rats exhibited cardiotoxicity, including cardiac dysfunction and injury, as well as disrupted mitochondrial and autophagic processes, increased inflammation, oxidative stress, apoptosis, ferroptosis, and pyroptosis. Co-administration of either Mdivi-1 or M1 with Trz alleviated these harmful effects, suggesting that modulating mitochondrial dynamics might offer a novel therapeutic strategy to mitigate Trz-induced cardiotoxicity.

Trastuzumab Duocarmazine in Pretreated Human Epidermal Growth Factor Receptor 2-Positive Advanced or Metastatic Breast Cancer: An Open-Label, Randomized, Phase III Trial (TULIP)

PURPOSE

Human epidermal growth factor receptor 2 (HER2)-targeted therapy is standard of care for HER2-positive (HER2+) breast cancer, but most patients develop progressive disease with persistent HER2 expression. No definitive treatment guidance currently exists beyond second line. Trastuzumab duocarmazine (T-Duo) is a third-generation, HER2-targeted antibody-drug conjugate that demonstrated efficacy and acceptable safety in phase I studies of heavily pretreated patients with HER2+/HER2-low breast cancer.

METHODS

In this open-label, randomized, phase III trial, T-Duo was compared with physician's choice (PC) in patients with unresectable locally advanced/metastatic HER2+ breast cancer with progression during/after ≥2 HER2-targeted therapies or after trastuzumab emtansine (T-DM1). The primary endpoint was progression-free survival (PFS) by blinded independent central review.

RESULTS

In total, 437 patients were randomly assigned 2:1 to T-Duo (n = 291) or PC (n = 146). The median age was 56.0 years (range, 24-86); most patients (93.6%) had metastatic disease. The median time from diagnosis of metastatic disease to trial entry was 3.5 years; the median number of prior HER2-targeted therapies in metastatic setting was three. The median PFS was 7.0 months (95% CI, 5.4 to 7.2) with T-Duo versus 4.9 months (95% CI, 4.0 to 5.5; hazard ratio [HR], 0.64 [95% CI, 0.49 to 0.84]; P = .002) with PC. PFS benefit was maintained across most predefined subgroups. The median overall survival (first analysis) was 20.4 (T-Duo) versus 16.3 months (PC; HR, 0.83 [95% CI, 0.62 to 1.09]; P = .153). Objective response rate was 27.8% (T-Duo) versus 29.5% (PC); other efficacy end points-clinical benefit rate, duration of response, and reduction in target lesion measurement-tended to favor T-Duo. Grade ≥3 treatment-emergent adverse events occurred in 52.8% (T-Duo) versus 48.2% (PC).

CONCLUSION

Treatment with T-Duo was manageable, but tolerability was affected by prevalent ocular toxicity, leading to a higher discontinuation rate in the T-Duo arm. T-Duo significantly reduced the risk of progression in patients with advanced HER2+ breast cancer who have progressed during/after ≥2 HER2-targeted therapies or after T-DM1.

Unlocking Natural Potential: Antibody-Drug Conjugates With Naturally Derived Payloads for Cancer Therapy

Natural compound-derived chemotherapies remain central to cancer treatment, however, they often cause off-target side effects that negatively impact patients' quality of life. In contrast, antibody-drug conjugates (ADCs) combine cytotoxic payloads with antibodies to specifically target cancer cells. Most approved and clinically investigated ADCs utilize naturally derived payloads, while those with conventional synthetic molecular payloads remain limited. This review focuses on approved ADCs that enhance the efficacy of naturally derived payloads by linking them with antibodies. We provide an overview of the core components of ADCs, their working mechanisms, and FDA-approved ADCs featuring naturally derived payloads, such as calicheamicin, camptothecin, dolastatin 10, maytansine, pyrrolbenzodiazepine (PBD), and the immunotoxin Pseudomonas exotoxin A. This review also explores recent clinical advancements aimed at broadening the therapeutic potential of ADCs, their applicability in treating heterogeneously composed tumors and their potential use beyond oncology. Additionally, this review highlights naturally derived payloads that are currently being clinically investigated but have not yet received approval. By summarizing the current landscape, this review provides insights into promising avenues for exploration and contributes to the refinement of treatment protocols for improved patient outcomes.

Development and Evaluation of a Remote Monitoring Regional Adjuvant Abemaciclib Service for Patients With High-Risk Early Breast Cancer

INTRODUCTION

Adjuvant abemaciclib was recently approved in high-risk early breast cancer, leading to an increase in oncology resource utilisation. We thus developed a regional, remote monitoring clinical service. The set-up, delivery processes and outcomes from the first 6 months' consecutive patients are presented.

METHODS

A regional delivery model with remote monitoring using optional electronic patient outcome measures (ePROMs) and bloods closer to home (BCTH) was implemented. Electronic patient records of patients entering the service (October 31, 2022 to May 31, 2023) were reviewed. Time-in-motion and on-line patient satisfaction surveys were conducted with questions adapted from prior questionnaires used by our cancer center. An independent t-test was used to assess differences in creatinine levels whilst on abemaciclib and a Mann-Whitney test to determine whether the time taken to complete follow-up appointments differed with and without ePROMs.

RESULTS

The first 103 patients to commence abemaciclib (median age 58 [range, 27-85], 66.0% White) had completed a median of 6 cycles (range, 0-9). 51.5% had treatment interruption, 52.4% a dose reduction and 15.5% discontinued therapy. Diarrhoea (90.3%), fatigue (84.9%) and anorexia (73.1%) were the most commonly reported toxicities on ePROMs. 10.8% of patients reported grade 3-4 toxicities. Neutropenia was also common and low grade. 89.5% of patients would recommend ePROMs and 98.0% found the BCTH service easy to use. Review appointments with ePROMs were a similar length to those without (P = .138).

CONCLUSIONS

We have successfully implemented a remote, regional adjuvant clinical service which could serve as a blueprint for other NHS trusts for this and other cancer drugs.

Outcome and toxicities of postmastectomy radiotherapy with integral cervicothoracic thermoplastic mask

BACKGROUND

Appropriate immobilization setup for postmastectomy radiotherapy may help to improve tumor control and to reduce radiation-related toxicities. This study aims at retrospectively evaluate the outcome and toxicities of postmastectomy radiotherapy (PMRT) with a novel integral cervicothoracic thermoplastic mask strategy.

METHODS

Breast cancer patients were treated with modified radical mastectomy and PMRT. Patient immobilization setup was performed with the placement of a 1-cm thickened wax film on the ipsilateral chest wall and an integral cervicothoracic thermoplastic mask. PMRT was delivered according to the institutional protocol. Dose distribution, disease control, patient survival and radiation-induced toxicities were evaluated.

RESULTS

Four-hundred nineteen eligible patients with complete follow-up information were included in the final analysis. The median follow-up was 40.2 (95%CI: 38.9-41.6) months. Two (0.5%) patients had local recurrence and 48 (11.4%) patients had distant metastasis. There were 22 (5.3%) deaths from all causes, of which 19 were caused by breast cancer. The 3-year overall survival (OS) rate was 94.8%. ER status, PR status, triple negative status, and T stages were significantly related to patient survival (p < 0.05). HER2 expression, N stage were not significantly related to patient survival. Most common radiation-induced toxicities included grade I (87.6%) and grade II (10.2%) dermatitis, and grade I pneumonitis (28.9%) found by chest X-ray or CT scans. No clinical detectable cardiovascular event related to radiotherapy was identified.

CONCLUSION

Postmastectomy radiotherapy with integral cervicothoracic thermoplastic mask leads to favorable outcome and moderate toxicities compared with results reported in literature and might be of clinical significance in breast cancer patient. However, this approach has not been compared directly with postmastectomy radiotherapy without immobilization, and its applicability in other regions with different treatment protocols requires further investigation.

Xianling Lianxia formula improves the efficacy of trastuzumab by enhancing NK cell-mediated ADCC in HER2-positive BC

Trastuzumab has improved survival rates in human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC), but drug resistance leads to treatment failure. Natural killer (NK) cell-mediated antibody-dependent cell cytotoxicity (ADCC) represents an essential antitumor immune mechanism of trastuzumab. Traditional Chinese medicine (TCM) has been used for centuries to treat diseases because of its capacity to improve immune responses. Xianling Lianxia formula (XLLXF), based on the principle of "strengthening body and eliminating toxin", exhibits a synergistic effect in the trastuzumab treatment of patients with HER2-positive BC. Notably, this synergistic effect of XLLXF was executed by enhancing NK cells and ADCC, as demonstrated through in vitro co-culture of NK cells and BC cells and in vivo intervention experiments. Mechanistically, the augmented impact of XLLXF on NK cells is linked to a decrease in cytokine inducible Src homology 2 (SH2) containing protein (CISH) expression, which in turn activates the Janus kinase 1 (JAK1)/signal transducer and activator of transcription 5 (STAT5) pathway. Collectively, these findings suggested that XLLXF holds promise for enhancing NK cell function and sensitizing patients with HER2-positive BC to trastuzumab.

A randomized phase III double-blind placebo-controlled trial of first-line chemotherapy and trastuzumab with or without bevacizumab for patients with HER2/neu-positive metastatic breast cancer: a trial of the ECOG-ACRIN Cancer Research Group (E1105)

BACKGROUND

In 2008, bevacizumab received accelerated Food and Drug Administration (FDA) approval for use in human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). Based on the pre-clinical and preliminary clinical activity of the trastuzumab and bevacizumab combination, ECOG-ACRIN E1105 trial was developed to determine if the addition of bevacizumab to a chemotherapy and trastuzumab combination for first-line therapy would improve progression-free survival (PFS) in patients with HER2-positive MBC.

FINDINGS

96 patients were randomized to receive standard first-line chemotherapy and trastuzumab with or without bevacizumab between November 2007 and October 2009, and 93 began protocol therapy. Induction therapy was given for 24 weeks, followed by maintenance trastuzumab with or without bevacizumab. 60% (56/93) began carboplatin and 74% (69/93) completed 6 cycles of induction therapy. Primary endpoint was PFS. Median PFS was 11.1 and 13.8 months for placebo and bevacizumab arms, respectively (hazard ratio [HR] 95%, Confidence Interval [Cl] for bevacizumab vs. placebo: 0.73 [0.43-1.23], p = 0.24), and at a median follow-up of 70.7 months, median survival was 49.1 and 63 months (HR [95% Cl] for OS: 1.09 [0.61-1.97], p = 0.75). The most common toxicities across both arms were neutropenia and hypertension, with left ventricular systolic dysfunction, fatigue, and sensory neuropathy reported more frequently with bevacizumab.

CONCLUSIONS

In this trial, the addition of bevacizumab did not improve outcomes in patients with metastatic HER2-positive breast cancer. Although the trial was underpowered due to smaller than anticipated sample size, these findings corroborated other clinical trials during this time.

CLINICAL TRIAL INFORMATION

NCT00520975.

Neoadjuvant T-DM1 for HER2-positive breast cancer used as a bridging strategy during COVID-19 pandemic: lessons learned-a case series

Background

Coronavirus disease 19 (COVID-19) has played a pivotal role in changing medical care around the world. During the pandemic, the operating rooms (ORs) were closed to elective surgery. Since breast cancer surgery is not regarded as an emergent procedure, there was an adoption of treatment regimen modification due to delays in treatment. Therefore, a decision was made to bridge early-stage HER2-positive breast cancer patients with neoadjuvant treatment to postpone surgery. Consequently, to reduce the frequency of dosing and the number of visits, as well as avoid steroid premedication, these patients were treated with ado-trastuzumab emtansine (T-DM1) every three weeks as opposed to weekly taxol and herceptin (TH).

Case Description

Five patients with early-stage HER2-positive cancer were treated with neoadjuvant T-DM1 3.6 mg/kg IV every three weeks. Three of the five patients developed cancer progression identified by their physical exam and/or imaging. T-DM1 was discontinued, and all three patients underwent immediate surgery. The remaining two patients, 4 and 5, had a complete and partial pathological response, respectively. All five patients received adjuvant therapy after surgery, and currently, none of these patients show evidence of disease on follow-up.

Conclusions

Our findings underscore the obstacles and treatment challenges encountered during the COVID-19 pandemic while preventing the spread of the virus and cancer progression. Furthermore, the use of T-DM1 for neoadjuvant treatment remains controversial, particularly when T-DM1 is used as a bridge to surgery during critical times. Perhaps better patient selection or a different drug regimen could have resulted in a better outcome in our study.

A randomized phase III double-blind placebo-controlled trial of first line chemotherapy and trastuzumab with or without bevacizumab for patients with HER2/neu-positive metastatic breast cancer: a trial of the ECOG-ACRIN Cancer Research Group (E1105)

Background

In 2008, bevacizumab received accelerated Food and Drug Administration (FDA) approval for use in human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). Based on the preclinical and preliminary clinical activity of the trastuzumab and bevacizumab combination, ECOG-ACRIN E1105 trial was developed to determine if the addition of bevacizumab to a chemotherapy and trastuzumab combination for first-line therapy would improve progression-free survival (PFS) in patients with HER2-positive MBC.

Findings

96 patients were randomized to receive standard first-line chemotherapy and trastuzumab with or without bevacizumab between November 2007 and October 2009, and 93 began protocol therapy. Induction therapy was given for 24 weeks, followed by maintenance trastuzumab with or without bevacizumab. 60% (56/93) began carboplatin and 74% (69/93) completed 6 cycles of induction therapy. Primary endpoint was PFS. Median PFS was 11.1 and 13.8 months for placebo and bevacizumab arms, respectively (hazard ratio [HR] 95%, Confidence Interval [Cl] for bevacizumab vs. placebo: 0.73 [0.43-1.23], p = 0.24), and at a median follow-up of 70.7 months, median survival was 49.1 and 63 months (HR [95% Cl] for OS: 1.09 [0.61-1.97], p = 0.75). The most common toxicities across both arms were neutropenia and hypertension, with left ventricular systolic dysfunction, fatigue, and sensory neuropathy reported more frequently with bevacizumab.

Conclusions

In this trial, the addition of bevacizumab did not improve outcomes in patients with metastatic HER2-positive breast cancer. Although the trial was underpowered due to smaller than anticipated sample size, these findings corroborated other clinical trials during this time.

The prognostic value of absolute lymphocyte count and neutrophil-to-lymphocyte ratio for patients with metastatic breast cancer: a systematic review and meta-analysis

Background

Neutrophil-to-lymphocyte ratio (NLR) is considered a potential prognostic marker in early breast cancer. However, the prognosis of absolute lymphocyte count (ALC) and NLR in metastatic breast cancer (MBC) has been reported in a few studies, and conclusions are still conflicting. This present manuscript aims to provide further solid evidence regarding the prognostic values of ALC and NLR in MBC patients.

Method

Eligible studies that reported the associations between ALC or NLR and MBC were included by searching relative electronic databases. Overall survival (OS) and progression-free survival (PFS) were used as outcome measures. The hazard ratio (HR) values and 95% confidence interval (CI) of the outcome measures were collected as effect sizes, and further analysis and discussion were conducted according to the pooled HR, subgroup analysis, publication bias, and interstudy heterogeneity.

Results

Twenty-nine studies comprising 3,973 patients with MBC were included. According to our findings, lower ALC was significantly associated with poorer prognosis of OS (HR = 0.57, 95% CI 0.48 to 0.68) and PFS (HR = 0.68, 95% CI 0.58 to 0.79), and greater NLR was associated with poorer OS (HR = 1.50, 95% CI 1.35 to 1.67) and PFS (HR = 1.82, 95% CI 1.42 to 2.35). Furthermore, the prognostic values of ALC and NLR in MBC were also observed in the subgroup analyses regarding cutoff values and ethnicities.

Conclusion

Low ALC and elevated NLR were observed to be significantly associated with adverse OS and PFS in MBC, indicating that ALC and NLR may act as potential prognostic biomarkers of MBC patients. Meanwhile, our results will also provide some novel evidence and research clues for the selection and development of clinical treatment strategies for MBC patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021224114.

A Comprehensive Review on the State of the Art of Breast Cancers in Italy

Breast cancer (BC) currently represents one of the most prevalent cancers among women worldwide and the leading cause of cancer death among women, also negatively affecting the quality of life (QoL) in patients. Over the past two decades, BC research has led to extraordinary advances in our understanding of the disease, resulting in more effective treatments. However, its occurrence is still increasing. Several new treatments are now under development worldwide, but they are not devoid of wellknown side effects, and a great number of patients develop endocrine resistance. Nevertheless, the design and synthesis of more suitable strategies and new drugs to treat breast cancers, overcome resistance and side effects, and obtain better therapeutic outcomes are needed. In this review, we summarize the therapies and the clinical studies currently ongoing in Italy for the treatment of BCs, mainly HER2+ MBC, HER2-low MBC, and TNBC, focusing on the most recent ones, also in consideration of diverse facets, including some aspects related to QoL. Finally, some studies related to the usefulness of physical activity in BC will be cited.

A disproportionality analysis of adverse events associated to pertuzumab in the FDA Adverse Event Reporting System (FAERS)

BACKGROUND

Pertuzumab is widely used for the treatment of HER2 + breast cancer. But its safety in the real world should be continuously monitored. So, we evaluated the safety of pertuzumab by pharmacovigilance analyze based on related adverse events (AEs) from the FDA Adverse Event Reporting System (FAERS) and find whether potential or uncertain adverse events were present.

METHODS

In disproportionality analysis, four algorithms were employed to detect the signals of pertuzumab from the FAERS between 2012 and 2022. In addition, we also used MYSQL 8.0, Navicat Premium 15, and Microsoft EXCEL 2019 to analyze the potential and high-ROR (reporting odds ratio) signals of pertuzumab. We also collected the onset times of pertuzumab-associated AEs.

RESULTS

From January 2012 to December 2022, there are 39,190,598 AEs reported from the FAERS database, of which 14,707 AEs listed pertuzumab as the 'primary suspected (PS)' drug. A total of 115 (46 potential) significant disproportionality preferred terms (PTs) conforming to the four algorithms were retained. Finally, we detected that the pertuzumab-induced AEs occurred in 12 organ systems. For pertuzumab, unexpected and significant PTs of AEs were found, including but not limited to below PTs: haematotoxicity, cardiotoxicity, cardiomyopathy, mitral valve incompetence, tachycardia, intestinal perforation, hemorrhoids, erysipelas, dehydration, pneumonitis, skin toxicity, onychomadesis, cyanosis, and circulatory collapse. We found there were 9 strong signals (5 potential safety signals) and 68 medium intensity signals (21 potential safety signals) according to IC025 (information component). The potential strong signals (IC025 > 3.0) were myelosuppression, cardiotoxicity, cardiac dysfunction, ejection fraction decreased, interstitial lung disease, and onychomadesis. Excluding unreported or unreasonable onset time reports, a total of 2016 AEs reported onset time and the median onset time was 117 days (4, 96), as median (Q1, Q3). Notably, most of the all AEs (n = 1133, 56%) and cardiac-related events (n = 405, 53%) all occurred within one month after pertuzumab therapy.

CONCLUSION

Analysis of FAERS data identified pertuzumab-associated AEs, and our findings supported continuous clinical monitoring, pharmacovigilance, and further studies of pertuzumab. A significant association was detected between pertuzumab and some potential adverse events which should be regarded with some care. We have to pay attention to the first month after pertuzumab therapy and prepare emergency measures, especially for the elderly and patients with cardiovascular diseases.

Acetylcholinesterase inhibition protects against trastuzumab-induced cardiotoxicity through reducing multiple programmed cell death pathways

BACKGROUND

Trastuzumab (Trz)-induced cardiotoxicity (TIC) is one of the most common adverse effects of targeted anticancer agents. Although oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, and ferroptosis have been identified as potential mechanisms underlying TIC, the roles of pyroptosis and necroptosis under TIC have never been investigated. It has been shown that inhibition of acetylcholinesterase function by using donepezil exerts protective effects in various heart diseases. However, it remains unknown whether donepezil exerts anti-cardiotoxic effects in rats with TIC. We hypothesized that donepezil reduces mitochondrial dysfunction, inflammation, oxidative stress, and cardiomyocyte death, leading to improved left ventricular (LV) function in rats with TIC.

METHODS

Male Wistar rats were randomly assigned to be Control or Trz groups (Trz 4 mg/kg/day, 7 days, I.P.). Rats in Trz groups were assigned to be co-treated with either drinking water (Trz group) or donepezil 5 mg/kg/day (Trz + DPZ group) via oral gavage for 7 days. Cardiac function, heart rate variability (HRV), and biochemical parameters were evaluated.

RESULTS

Trz-treated rats had impaired LV function, HRV, mitochondrial function, and increased inflammation and oxidative stress, leading to apoptosis, ferroptosis, and pyroptosis. Donepezil co-treatment effectively decreased those adverse effects of TIC, resulting in improved LV function. An in vitro study revealed that the cytoprotective effects of donepezil were abolished by a muscarinic acetylcholine receptor (mAChR) antagonist.

CONCLUSIONS

Donepezil exerted cardioprotection against TIC via attenuating mitochondrial dysfunction, oxidative stress, inflammation, and cardiomyocyte death, leading to improved LV function through mAChR activation. This suggests that donepezil could be a novel intervention strategy in TIC.

Recent Developments in Combination Chemotherapy for Colorectal and Breast Cancers with Topoisomerase Inhibitors

DNA topoisomerases are important enzymes that stabilize DNA supercoiling and resolve entanglements. There are two main types of topoisomerases in all cells: type I, which causes single-stranded DNA breaks, and type II, which cuts double-stranded DNA. Topoisomerase activity is particularly increased in rapidly dividing cells, such as cancer cells. Topoisomerase inhibitors have been an effective chemotherapeutic option for the treatment of several cancers. In addition, combination cancer therapy with topoisomerase inhibitors may increase therapeutic efficacy and decrease resistance or side effects. Topoisomerase inhibitors are currently being used worldwide, including in the United States, and clinical trials on the combination of topoisomerase inhibitors with other drugs are currently underway. The primary objective of this review was to comprehensively analyze the current clinical landscape concerning the combined application of irinotecan, an extensively investigated type I topoisomerase inhibitor for colorectal cancer, and doxorubicin, an extensively researched type II topoisomerase inhibitor for breast cancer, while presenting a novel approach for cancer therapy.