Cardiotoxicity in breast cancer treatment: Causes and mitigation

Survivorship issues and treatment related toxicities have considerably increased in breast cancer patients following improved therapeutic options. Cardiotoxicity has been a major treatment related side effects in these patients. Despite this being a well-known entity, the real magnitude of the problem remains an enigma. The amount of research in mitigation of cardiotoxicity or its management in breast cancer survivors is limited and there is an urgent need for finding solutions for the problem. In this article, we are reviewing the agents that cause cardiotoxicity and suggesting a proposal for follow up of breast cancer survivors in an attempt to reduce the magnitude of impact on their quality of life.

Pertuzumab Cardiotoxicity in Patients With HER2-Positive Cancer: A Systematic Review and Meta-analysis

Background

Human epidermal growth factor receptor 2 (HER2) overexpressing malignancies, including breast and gastro-esophageal, are associated with a poor prognosis. The cardiotoxicity of trastuzumab, a HER2-targeting monoclonal antibody, is well established. However, the cardiotoxic effect of pertuzumab, another HER2-directed therapy, is less well documented. The objective of this systematic review and meta-analysis was to determine the risk of cardiac events in patients with HER2-positive cancer who are receiving pertuzumab.

Methods

We performed a systematic review of phase 2 and 3 randomized controlled trials in which the addition of pertuzumab to other standard therapies in patients with stage I-IV HER2-positive cancer was evaluated, and cardiac adverse effects reported. We searched MEDLINE (1946-2020), Embase (1974-2020), and CENTRAL. Two independent reviewers assessed the risk of bias and extracted the data. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated from the pooled data using the inverse variance method and random-effects models.

Results

Eight randomized controlled trials (8420 patients) were included: 1 was gastro-esophageal; 7 were breast cancer trials. Participants’ median age ranged from 49 to 61.5 years. All participants received trastuzumab and chemotherapy in addition to pertuzumab or placebo. Compared with placebo, pertuzumab increased the risk of clinical heart failure (HF; RR [95% CI]: 1.97 [1.05-3.70]; I² = 0%). However, pertuzumab had no demonstrable effect on asymptomatic/minimally symptomatic left ventricular systolic dysfunction (RR [95% CI]: 1.19 [0.89-1.61]; I² = 19%).

Conclusions

Pertuzumab increases the risk of clinical HF, but not asymptomatic/minimally symptomatic left ventricular systolic dysfunction, in HER2-positive cancer patients. Further research into the mechanisms underlying pertuzumab-related HF is needed to understand its clinical spectrum of cardiotoxicity.

A randomized, double-blind, single-dose, single-center, parallel phase I clinical study comparing the pharmacokinetics, immunogenicity, safety, and tolerance of pertuzumab injection and Perjeta® in healthy Chinese male subjects

BACKGROUND

Perjeta® is a recombinant, humanized monoclonal antibody that has been marketed and approved for the targeted therapy of human epidermal growth factor receptor (HER2) positive breast cancer in the United States. This study compared the bioequivalence, immunogenicity, and safety of pertuzumab injection (a biosimilar of Perjeta® produced by Chia Tai Tianqing Pharmaceutical Group Co., Ltd) and Perjeta® (produced by Roche Pharma AG) in healthy Chinese males.

RESEARCH DESIGN AND METHODS

Healthy Chinese male subjects (N = 87) were randomly given intravenous injection of 5 mg/kg pertuzumab or Perjeta® at a 1:1 ratio. Plasma drug concentrations were detected by enzyme-linked immunosorbent assay, and primary pharmacokinetic parameters were statistically analyzed. We detected the levels of anti-drug antibody (ADA) and neutralizing antibody (nAb) to evaluate drug immunogenicity and safety of the drugs throughout the study.

RESULTS

The geometric mean ratios of AUC_0-t, C_max, and AUC_0-∞ for pertuzumab and Perjeta® were 100.42%, 96.71%, and 101.47%, respectively. The 90% CIs were all within 80%-125%, meeting the bioequivalence standards. The levels of ADA and nAb were similar. In addition, both had good safety in the study.

CONCLUSION

The study shows that pertuzumab injection and Perjeta® had similar bioequivalence, immunogenicity, and safety.

The biological activity of bispecific trastuzumab/pertuzumab plant biosimilars may be drastically boosted by disulfiram increasing formaldehyde accumulation in cancer cells

Studies of breast cancer therapy have examined the improvement of bispecific trastuzumab/pertuzumab antibodies interacting simultaneously with two different epitopes of the human epidermal growth factor receptor 2 (HER2). Here, we describe the creation and production of plant-made bispecific antibodies based on trastuzumab and pertuzumab plant biosimilars (bi-TPB-PPB). Using surface plasmon resonance analysis of bi-TPB-PPB antibodies binding with the HER2 extracellular domain, we showed that the obtained Kd values were within the limits accepted for modified trastuzumab and pertuzumab. Despite the ability of bi-TPB-PPB antibodies to bind to Fcγ receptor IIIa and HER2 oncoprotein on the cell surface, a proliferation inhibition assay did not reveal any effect until α1,3-fucose and β1,2-xylose in the Asn297-linked glycan were removed. Another approach to activating bi-TPB-PPB may be associated with the use of disulfiram (DSF) a known aldehyde dehydrogenase 2 (ALDH2) inhibitor. We found that disulfiram is capable of killing breast cancer cells with simultaneous formaldehyde accumulation. Furthermore, we investigated the capacity of DSF to act as an adjuvant for bi-TPB-PPB antibodies. Although the content of ALDH2 mRNA was decreased after BT-474 cell treatment with antibodies, we only observed cell proliferation inhibiting activity of bi-TPB-PPB in the presence of disulfiram. We concluded that disulfiram can serve as a booster and adjuvant for anticancer immunotherapy.

Novel Human Bispecific Aptamer-Antibody Conjugates for Efficient Cancer Cell Killing

Monoclonal antibodies have been approved by the Food and Drug Administration for the treatment of various human cancers. More recently, oligonucleotide aptamers have risen increasing attention for cancer therapy thanks to their low size (efficient tumor penetration) and lack of immunogenicity, even though the short half-life and lack of effector functions still hinder their clinical applications. Here, we demonstrate, for the first time, that two novel bispecific conjugates, consisting of an anti-epidermal growth factor receptor (EGFR) aptamer linked either with an anti-epidermal growth factor receptor 2 (ErbB2) compact antibody or with an immunomodulatory (anti-PD-L1) antibody, were easily and rapidly obtained. These novel aptamer-antibody conjugates retain the targeting ability of both the parental moieties and acquire a more potent cancer cell killing activity by combining their inhibitory properties. Furthermore, the conjugation of the anti-EGFR aptamer with the immunomodulatory antibody allowed for the efficient redirection and activation of T cells against cancer cells, thus dramatically enhancing the cytotoxicity of the two conjugated partners. We think that these bispecific antibody-aptamer conjugates could have optimal biological features for therapeutic applications, such as increased specificity for tumor cells expressing both targets and improved pharmacokinetic and pharmacodynamic properties due to the combined advantages of the aptamer and antibody.

A Comprehensive Review of US FDA-Approved Immune Checkpoint Inhibitors in Urothelial Carcinoma

Few effective treatment options are available for patients with advanced or metastatic urothelial carcinoma (UC) after unsuccessful first-line platinum-based chemotherapy. To date, immune checkpoint inhibitors are novel therapeutic agents for UC treatment. From May 2016 to May 2017, five anti-PD-1/PD-L1 monoclonal antibodies received accelerated or regular approval from the US Food and Drug Administration (FDA) for the treatment of patients with locally advanced or metastatic UC. The present comprehensive review presents the background information of these five US FDA-approved anticancer agents to provide a basic but concise understanding of these agents for advanced studies. We summarize their immune checkpoint mechanisms, clinical efficacy, recommended usage protocols, adverse events, and the limitations of the PD-L1 biomarker assays.

Trastuzumab and Pertuzumab Plant Biosimilars: Modification of Asn297-linked Glycan of the mAbs Produced in a Plant with Fucosyltransferase and Xylosyltransferase Gene Knockouts

Plant biosimilars of anticancer therapeutic antibodies are of interest not only because of the prospects of their practical use, but also as an instrument and object for study of plant protein glycosylation. In this work, we first designed a pertuzumab plant biosimilar (PPB) and investigated the composition of its Asn297-linked glycan in comparison with trastuzumab plant biosimilar (TPB). Both biosimilars were produced in wild-type (WT) Nicotiana benthamiana plant (PPB-WT and TPB-WT) and transgenic ΔXTFT N. benthamiana plant with XT and FT genes knockout (PPB-ΔXTFT and TPB-ΔXTFT). Western blot analysis with anti-α1,3-fucose and anti-xylose antibodies, as well as a test with peptide-N-glycosidase F, confirmed the absence of α1,3-fucose and xylose in the Asn297-linked glycan of PPB-ΔXTFT and TPB-ΔXTFT. Peptide analysis followed by the identification of glycomodified peptides using MALDI-TOF/TOF showed that PPB-WT and TPB-WT Asn297-linked glycans are mainly of complex type GnGnXF. The core of PPB-WT and TPB-WT Asn297-linked GnGn-type glycan contains α1,3-fucose and β1,2-xylose, which, along with the absence of terminal galactose and sialic acid, distinguishes these plant biosimilars from human IgG. Analysis of TPB-ΔXTFT total carbohydrate content indicates the possibility of changing the composition of the carbohydrate profile not only of the Fc, but also of the Fab portion of an antibody produced in transgenic ΔXTFT N. benthamiana plants. Nevertheless, study of the antigen-binding capacity of the biosimilars showed that absence of xylose and fucose residues in the Asn297-linked glycans does not affect the ability of the glycomodified antibodies to interact with HER2/neu positive cancer cells.

HER2-Positive Metastatic Breast Cancer Patients Receiving Pertuzumab in a Community Oncology Practice Setting: Treatment Patterns and Outcomes

Background

Pertuzumab (Perjeta^®), a HER2/neu receptor antagonist, was approved by the US Food and Drug Administration in June 2012 for use in the first-line setting for patients with HER2-positive metastatic breast cancer (mBC).

Objective

This retrospective study investigated the clinical and demographic characteristics, treatment patterns, safety, and clinical outcomes for patients with HER2-positive mBC who received pertuzumab in the first-line setting in US community oncology practices.

Methods

Patients with HER2-positive mBC, who initiated pertuzumab within 60 days of mBC diagnosis between June 2012 and June 2014, followed through December 2014, had ≥2 visits within the McKesson Specialty Health/US Oncology Network, and were not on clinical trials during the study period, were eligible. This study utilized iKnowMed electronic health records, Claims Data Warehouse, and Social Security Death Index. Progression-free survival (PFS) was assessed by Kaplan–Meier methods.

Results

A total of 266 patients met the selection criteria. A vast majority of the patients (249/266, 93.6%) received a trastuzumab + pertuzumab + taxane (H + P + T) regimen. The number of patients with prior adjuvant/neoadjuvant therapy was higher than the CLEOPATRA trial, but age (median 57 years) and percentage of visceral disease (74.8%) were similar. The most common adverse events were fatigue (50.8%), diarrhea (44.7%), nausea (35.3%), peripheral neuropathy (33.5%), neutropenia (24.9%), and rash (24.4%). The median PFS was 16.9 months (95% CI 14.2–19.7).

Conclusions

In this retrospective study of patients with HER2-positive mBC receiving pertuzumab in the first-line setting, most patients were treated with H + P + T. The safety and PFS of H + P + T were consistent with those observed in the pivotal trial.

Cell-specific biomarkers and targeted biopharmaceuticals for breast cancer treatment

Breast cancer is the second leading cause of cancer death among women, and its related treatment has been attracting significant attention over the past decades. Among the various treatments, targeted therapy has shown great promise as a precision treatment, by binding to cancer cell-specific biomarkers. So far, great achievements have been made in targeted therapy of breast cancer. In this review, we first discuss cell-specific biomarkers, which are not only useful for classification of breast cancer subtyping but also can be utilized as goals for targeted therapy. Then, the innovative and generic-targeted biopharmaceuticals for breast cancer, including monoclonal antibodies, non-antibody proteins and small molecule drugs, are reviewed. Finally, we provide our outlook on future developments of biopharmaceuticals, and provide solutions to problems in this field.

HER2 in solid tumors: more than 10 years under the microscope; where are we now?

HER2 is a well-recognized mediator of the cancerogenic process. It is dysregulated in a wide range of solid tumors, mainly via protein overexpression and/or gene amplification, thus making HER2 an attractive target for tailored treatment. The anti-HER2 therapy trastuzumab was approved for the treatment of HER2-positive metastatic breast cancer patients more than 10 years ago. Since then, trastuzumab and other HER2-inhibitors have been entered into clinical practice for the treatment of breast cancer and, more recently, have been approved to treat HER2-positive metastatic gastric cancers. Currently, HER2-targeted therapies are under evaluation in other tumor types. Due to the relevance of proper patient selection, the accurate assessment of HER2 status is fundamental. This review will discuss the established knowledge and novel insights into the HER2 story, mainly focusing on breast, gastric and colorectal cancers, as well as providing a brief overview of salivary gland, bladder, ovarian and lung tumors.

Effects of a second-generation human anti-ErbB2 ImmunoRNase on trastuzumab-resistant tumors and cardiac cells

The inhibition of ErbB2 by the use of human antibodies can be a valuable strategy for the treatment of breast and gastric cancer. Trastuzumab, a humanized anti-ErbB2 antibody in clinical use, is effective but can engender resistance as well as cardiotoxicity. ImmunoRNases, made up of a human anti-ErbB2 scFv and human pancreatic ribonucleases (HP-RNases), have been engineered to overcome the limits of other immunotoxins, such as immunogenicity and nonspecific toxicity. Here, we report that a novel anti-ErbB2 immunoRNase, called Erb-HPDDADD-RNase, obtained by fusing Erbicin, a human ErbB2-directed scFv, with an HP-RNase variant that resists the cytosolic inhibitor protein, binds with high affinity to a panel of ErbB2-positive gastric tumor cells and inhibits their growth more than does the parental immunoRNase, which is not resistant to the inhibitor. Moreover, Erb-HP-DDADD-RNase is endowed with antiproliferative activity for trastuzumab-resistant cancer cells both in vitro and in vivo that is more potent than that of the parental immunoRNase. Importantly, Erb-HP-DDADD-RNase does not show cardiotoxic effects in vitro on human cardiomyocytes and does not impair cardiac function in a mouse model. Thus, Erb-HP-DDADD-RNase could fulfil the therapeutic need of cancer patients ineligible for trastuzumab treatment due to primary or acquired trastuzumab resistance or to cardiac dysfunction.