First FDA Approval of Dual Anti-HER2 Regimen: Pertuzumab in Combination with Trastuzumab and Docetaxel for HER2-Positive Metastatic Breast Cancer

Depicting Biomarkers for HER2-Inhibitor Resistance: Implication for Therapy in HER2-Positive Breast Cancer

HER2 (human epidermal growth factor receptor 2) is highly expressed in a variety of cancers, including breast, lung, gastric, and pancreatic cancers. Its amplification is linked to poor clinical outcomes. At the genetic level, HER2 is encoded by the ERBB2 gene (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), which is frequently mutated or amplified in cancers, thus spurring extensive research into HER2 modulation and inhibition as viable anti-cancer strategies. An impressive body of FDA-approved drugs, including anti-HER2 monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and HER2-tyrosine kinase inhibitors (TKIs), have demonstrated success in enhancing overall survival (OS) and disease progression-free survival (PFS). Yet, drug resistance remains a persistent challenge and raises the risks of metastatic potential and tumor relapse. Research into alternative therapeutic options for HER2+ breast cancer therefore proves critical for adapting to this ever-evolving landscape. This review highlights current HER2-targeted therapies, discusses predictive biomarkers for drug resistance, and introduces promising emergent therapies-especially combination therapies-that are aimed at overcoming drug resistance in the context of HER2+ breast cancer.

A Randomized, Double-Blind, Phase III Study in India for Comparing Efficacy, Safety, and PK of ZRC-3277 (Pertuzumab Biosimilar) With Perjeta® in Patients With HER2-Positive Metastatic Breast Cancer

INTRODUCTION

To evaluate the efficacy, safety, pharmacokinetics (PK), and immunogenicity of ZRC-3277 (pertuzumab biosimilar) with Perjeta® (pertuzumab) in previously untreated patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC).

PATIENTS AND METHODS

This phase III, multicenter, double-blind study across 38 sites in India randomized (1:1) patients with HER2-positive MBC in either the ZRC-3277 or Perjeta® group. Both groups also received trastuzumab and docetaxel. Of 268 enrolled patients, mITT population had 243 patients (119 and 124 in the ZRC-3277 and Perjeta® groups, respectively). The primary objective was to compare the between-group objective response rate (ORR) after 6 cycles of treatment. ORR was determined by evaluating scans of computed tomography or magnetic resonance imaging following Response Evaluation Criteria in Solid Tumor (RECIST 1.1). Two-sided 95% confidence interval (95% CI) for the difference in ORR was determined to evaluate the noninferiority of ZRC-3277 to Perjeta®. The secondary outcomes included the assessment of PK, immunogenicity, and safety between the 2 groups.

RESULTS

In the mITT population, 104 (87.39%) and 114 (91.94%) participants achieved the ORR in the ZRC-3277 and Perjeta® groups, respectively. For predefined -15% noninferiority margin, obtained 2-sided 95% CIs (-12.19%, 3.11%) for the difference in ORR (-4.55%) between the 2 groups demonstrated the noninferiority of ZRC-3277 to Perjeta®. PK, immunogenicity, and safety were not significantly different between the 2 groups.

CONCLUSION

Efficacy, PK, immunogenicity, and safety profiles of ZRC-3277 was found to be similar to those of Perjeta®.

Structure and conformational variability of the HER2-trastuzumab-pertuzumab complex

Single particle analysis from cryogenic transmission electron microscopy (cryo-EM) is particularly attractive for complexes for which structure prediction remains intractable, such as antibody-antigen complexes. Here we obtain the detailed structure of a particularly difficult complex between human epidermal growth factor receptor 2 (HER2) and the antigen-binding fragments from two distinct therapeutic antibodies binding to distant parts of the flexible HER2, pertuzumab and trastuzumab (HTP). We highlight the strengths and limitations of current data processing software in dealing with various kinds of heterogeneities, particularly continuous conformational heterogeneity, and in describing the motions that can be extracted from our dataset. Our HTP structure provides a more detailed view than the one previously available for this ternary complex. This allowed us to pinpoint a previously overlooked loop in domain IV that may be involved both in binding of trastuzumab and in HER2 dimerization. This finding may contribute to explain the synergistic anticancer effect of the two antibodies. We further propose that the flexibility of the HTP complex, beyond the difficulties it causes for cryo-EM analysis, actually reflects regulation of HER2 signaling and its inhibition by therapeutic antibodies. Notably we obtain our best data with ultra-thin continuous carbon grids, showing that with current cameras their use to alleviate particle misdistribution is compatible with a protein complex of only 162 kDa. Perhaps most importantly, we provide here a dataset for such a smallish protein complex for further development of software accounting for continuous conformational heterogeneity in cryo-EM images.

A clinical systematic literature review of treatments among patients with advanced and/or metastatic human epidermal growth factor receptor 2 positive breast cancer

Aim: This systematic literature review aims to summarize the efficacy/effectiveness of treatments, including eribulin (ERI)-based and anti-human epidermal growth factor receptor 2 (HER2) treatments in advanced/metastatic HER2+ breast cancer. Methods: Three databases from 2016 to September 2021 were searched for clinical trials and observational studies in patients receiving first-line (1L) standard of care (SOC), second-line (2L) SOC or third-line or subsequent lines (3L+). Results: 2692 citations were screened, and 38 studies were included. Eleven studies were randomized-controlled trials (RCTs; 5 in 1L, 6 in 3L+), 6 were single-arm trials (5 in 1L, 1 in 3L+) and 21 were observational studies (13 in 1L, 6 in 2L, 4 in 3L+ [note that studies with subgroups for 1L, 2L, 3L+ are double-counted]). Longer overall survival (OS) was associated with 1L and 2L treatment, and for 3L+ studies that included ERI, ERI or trastuzumab (Tmab) + ERI led to longer OS than treatments of physician's choice (median OS of 11, 10 and 8.9 months, respectively). Progression-free survival was 9 months in Tmab + pertuzumab (Pmab) + ERI, 4 months in Tmab + ERI and 3.3 months in ERI. Conclusion: Available treatments provide a wide range of efficacy. However, later lines lack standardization and conclusions on comparative effectiveness are limited by differing trial designs. Thus, the chance of prolonged survival with new agents warrants further research.

A Vector Nanoplatform for the Bioimaging of Deep-Seated Tumors

Today, in preclinical studies, optical bioimaging based on luminescence and fluorescence is indispensable in studying the development of neoplastic transformations, the proliferative activity of the tumor, its metastatic potential, as well as the therapeutic effect of antitumor agents. In order to expand the capabilities of optical imaging, sensors based on the bioluminescence resonance energy transfer (BRET) mechanism and, therefore, independent of an external light source are being developed. A targeted nanoplatform based on HER2-specific liposomes whose internal environment contains a genetically encoded BRET sensor was developed in this study to visualize deep-seated tumors characterized by overexpression of human epidermal growth factor receptor type 2 (HER2). The BRET sensor is a hybrid protein consisting of the highly catalytic luciferase NanoLuc (an energy donor) and a LSSmKate1 red fluorescent protein with a large Stokes shift (an energy acceptor). During the bioimaging of disseminated intraperitoneal tumors formed by HER2-positive SKOV3.ip1cells of serous ovarian cystadenocarcinoma, it was shown that the developed system is applicable in detecting deep-seated tumors of a certain molecular profile. The developed system can become an efficient platform for optimizing preclinical studies of novel targeted drugs.

Ferroptosis biomarkers predict tumor mutation burden's impact on prognosis in HER2-positive breast cancer

BACKGROUND

Ferroptosis has recently been associated with multiple degenerative diseases. Ferroptosis induction in cancer cells is a feasible method for treating neoplastic diseases. However, the association of iron proliferation-related genes with prognosis in HER2+ breast cancer (BC) patients is unclear.

AIM

To identify and evaluate fresh ferroptosis-related biomarkers for HER2+ BC.

METHODS

First, we obtained the mRNA expression profiles and clinical information of HER2+ BC patients from the TCGA and METABRIC public databases. A four-gene prediction model comprising PROM2, SLC7A11, FANCD2, and FH was subsequently developed in the TCGA cohort and confirmed in the METABRIC cohort. Patients were stratified into high-risk and low-risk groups based on their median risk score, an independent predictor of overall survival (OS). Based on these findings, immune infiltration, mutations, and medication sensitivity were analyzed in various risk groupings. Additionally, we assessed patient prognosis by combining the tumor mutation burden (TMB) with risk score. Finally, we evaluated the expression of critical genes by analyzing single-cell RNA sequencing (scRNA-seq) data from malignant vs normal epithelial cells.

RESULTS

We found that the higher the risk score was, the worse the prognosis was (P < 0.05). We also found that the immune cell infiltration, mutation, and drug sensitivity were different between the different risk groups. The high-risk subgroup was associated with lower immune scores and high TMB. Moreover, we found that the combination of the TMB and risk score could stratify patients into three groups with distinct prognoses. HRisk-HTMB patients had the worst prognosis, whereas LRisk-LTMB patients had the best prognosis (P < 0.0001). Analysis of the scRNA-seq data showed that PROM2, SLC7A11, and FANCD2 were significantly differentially expressed, whereas FH was not, suggesting that these genes are expressed mainly in cancer epithelial cells (P < 0.01).

CONCLUSION

Our model helps guide the prognosis of HER2+ breast cancer patients, and its combination with the TMB can aid in more accurate assessment of patient prognosis and provide new ideas for further diagnosis and treatment.

Standard-of-Care Treatment for HER2+ Metastatic Breast Cancer and Emerging Therapeutic Options

Prior to the advent of the HER2-targeted monoclonal antibody trastuzumab, HER2+ breast cancer (BC) was considered an aggressive disease with a poor prognosis. Over the past 25 years, innovations in molecular biology, pathology, and early therapeutics have transformed the treatment landscape. With the advent of multiple HER2-directed therapies, there have been immense improvements in oncological outcomes in both adjuvant and metastatic settings. Currently, 8 HER2-targeted therapies are approved by the Food and Drug Administration (FDA) for the treatment of early-stage and/or advanced/metastatic disease. Nonetheless, approximately 25% of patients develop recurrent disease or metastasis after HER2-targeted therapy and most patients with HER2+ metastatic breast cancer (MBC) die from their disease. Given the many mechanisms of resistance to HER2-directed therapy, there is a pressing need to further personalize care for patients with HER2+ MBC, by the identification of reliable predictive biomarkers, and the development of novel therapies and combination regimens to overcome therapeutic resistance. Of particular interest are established and novel antibody-drug conjugates, as well as other novel therapeutics and multifaceted approaches to harness the immune system (checkpoint inhibitors, bispecific antibodies, and vaccine therapy). Herein, we discuss standard-of-care treatment of HER2+ MBC, including the management of breast cancer brain metastases (BCBM). Furthermore, we highlight novel treatment approaches for HER2+ MBC, including endeavors to personalize therapy, and discuss ongoing controversies and challenges.

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

PURPOSE

The combination of trastuzumab and pertuzumab (HP) as part of a taxane-based regimen has shown benefit in the adjuvant and metastatic HER2 + breast cancer setting. In the CLEOPATRA trial, pruritus was reported in 11-17.6% of patients. The clinical phenotype and potential treatment strategies for this event have not been reported.

METHODS

A retrospective review of 2583 patients receiving trastuzumab and pertuzumab for the treatment of HER2 + breast cancer from 11/23/2011 to 6/21/2021 was performed at Memorial Sloan Kettering Cancer Center (MSKCC). Patient demographics, pruritus characteristics, and treatments as documented in the electronic medical record (EMR) were included in this analysis.

RESULTS

Of 2583 pts treated with HP, 122 (4.72%) with pruritus were identified. On average, patients experienced pruritus 319.0 days (8-3171) after initiation of HP. The upper extremities (67.4%), back (29.3%), lower extremities (17.4%), and shoulders (14.1%) were the most commonly affected regions. Grade 1/2 pruritus (97.6%) occurred in most cases. Patients responded primarily to treatment with topical steroids (52.2%), antihistamines (29.9%), emollients (20.9%), and gabapentinoids (16.4%). Of those with pruritus, 4 patients (3.3%) required treatment interruption or discontinuation.

CONCLUSIONS

Pruritus is uncommon in patients on trastuzumab and pertuzumab, generally a chronic condition, with gabapentinoids or antihistamines representing effective therapies.

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.

Emerging Intrinsic Therapeutic Targets for Metastatic Breast Cancer

Breast cancer is now the most common cancer worldwide, and it is also the main cause of cancer-related death in women. Survival rates for female breast cancer have significantly improved due to early diagnosis and better treatment. Nevertheless, for patients with advanced or metastatic breast cancer, the survival rate is still low, reflecting a need for the development of new therapies. Mechanistic insights into metastatic breast cancer have provided excellent opportunities for developing novel therapeutic strategies. Although high-throughput approaches have identified several therapeutic targets in metastatic disease, some subtypes such as triple-negative breast cancer do not yet have an apparent tumor-specific receptor or pathway to target. Therefore, exploring new druggable targets in metastatic disease is a high clinical priority. In this review, we summarize the emerging intrinsic therapeutic targets for metastatic breast cancer, including cyclin D-dependent kinases CDK4 and CDK6, the PI3K/AKT/mTOR pathway, the insulin/IGF1R pathway, the EGFR/HER family, the JAK/STAT pathway, poly(ADP-ribose) polymerases (PARP), TROP-2, Src kinases, histone modification enzymes, activated growth factor receptors, androgen receptors, breast cancer stem cells, matrix metalloproteinases, and immune checkpoint proteins. We also review the latest development in breast cancer immunotherapy. Drugs that target these molecules/pathways are either already FDA-approved or currently being tested in clinical trials.

Pruritus Related to Trastuzumab and Pertuzumab in HER2+ Breast Cancer Patients

Purpose

The combination of trastuzumab and pertuzumab (HP) as part of a taxane-based regimen has shown benefit in the adjuvant and metastatic HER2+ breast cancer setting. In the CLEOPATRA trial, pruritus was reported in 11-17.6% of patients. The clinical phenotype and potential treatment strategies for this event have not been reported.

Methods

A retrospective review of 2583 patients receiving trastuzumab and pertuzumab for the treatment of HER2+ breast cancer from 11/23/2011 to 6/21/2021 was performed at Memorial Sloan Kettering Cancer Center (MSKCC). Patient demographics, pruritus characteristics, and treatments as documented in the electronic medical record (EMR) were included in this analysis.

Results

Of 2583 pts treated with HP, 122 (4.72%) with pruritus were identified. On average, patients experienced pruritus 319.0 days (8-3171) after initiation of HP. The upper extremities (67.4%), back (29.3%), lower extremities (17.4%), and shoulders (14.1%) were the most commonly affected regions. Grade 1/2 pruritus (97.6%) occurred in most cases. Patients responded primarily to treatment with topical steroids (52.2%), antihistamines (29.9%), emollients (20.9%), and gabapentinoids (16.4%). Of those with pruritus, 4 patients (3.3%) required treatment interruption or discontinuation.

Conclusions

Pruritus is uncommon in patients on trastuzumab and pertuzumab, generally a chronic condition, with gabapentinoids or antihistamines representing effective therapies.

Privileged Scaffolds in Drug Discovery against Human Epidermal Growth Factor Receptor 2 for Cancer Treatment

HER2 is the membrane receptor tyrosine kinase showing overexpression in several human malignancies, particularly breast cancer. HER2 overexpression causes the activation of Ras- MAPK and PI3K/Akt/ NF-κB cellular signal transduction pathways that lead to cancer development and progression. HER2 is, therefore, presumed as one of the key targets for the development of tumor-specific therapies. Several preclinical have been developed that function by inhibiting the HER2 tyrosine kinase activity through the prevention of the dimerization process. Most HER2 inhibitors act as ATP competitors and prevent the process of phosphorylation, and abort the cell cycle progression and proliferation. In this review, the clinical drug candidates and potent pre-clinical newly developed molecules are described, and the core chemical scaffolds typically responsible for anti-HER2 activity are deciphered. In addition, the monoclonal antibodies that are either used in monotherapy or in combination therapy against HER2-positive cancer are briefly described. The identified key moieties in this study could result in the discovery of more effective HER2-targeted anticancer drug molecules and circumvent the development of resistance by HER2-specific chemotherapeutics in the future.

A novel bispecific antibody able to pass the blood-brain barrier and therapeutically engage within the brain

The use of therapeutic antibodies for treating diseases in the CNS is hampered by the blood-brain barrier (BBB). In this issue, Edavettal et al.¹ report on a novel bioengineered antibody not only capable of passing the BBB but also for intervening in pathological protein deposition and subsequent induction of clearing by microglia.

Antibody drug conjugates targeting HER2: Clinical development in metastatic breast cancer

The identification of the HER2 alteration as an actionable oncogenic driver in breast cancer has propelled the development of HER-targeting monoclonal antibodies (mAb) such as trastuzumab and pertuzumab, which led to dramatic improvements in survival outcomes. Lately, the great strides made toward developing antibody-conjugation methods have led to the development of a new class of compelling compounds, the antibody-drug conjugates (ADCs) targeting HER2 which have profoundly transformed the treatment landscape of breast cancer. HER2-targeting ADCs, trastuzumab-emtansine and trastuzumab-deruxtecan, have improved the overall survival in the second and third-line settings with manageable adverse events. Other HER2-targeting ADCs using novel technological advances in the antibody, linker and/or payload conception have shown promising activity in preclinical and clinical studies and some of them are now being evaluated in larger clinical trials. Multiple challenges still impede the success of ADCs in breast cancer namely the lack of a comprehensive understanding of resistance mechanisms as well as the mechanisms of action of ADCs in special subgroups of patients such as those with low or ultra-low HER2 expression and patients with brain or leptomeningeal metastases (BM). In this framework, we review the approved indications and ongoing trials for HER2-targeting ADCs, across patient subgroups, including those with BM and discuss the associated potential mechanisms of action and resistance. Last, we provide an overview of the future perspectives involving HER2-targeting ADCs in breast cancer.

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.

A randomized, double-blind, parallel control study to evaluate the biosimilarity of QL1209 with Perjeta® in healthy male subjects

Purpose: This is the first study to compare the pharmacokinetics, safety and, immunogenicity of QL1209, a biosimilar of Perjeta^®.

Methods: This study was a randomized, double-blind, parallel-controlled clinical trial evaluating the biosimilarity between QL1209 (specification: 420 mg:14 ml, single use via, manufacturer: Qilu Pharmaceutical Co., Ltd., batch number: 201808001KJL) and Perjeta^® (specification: 420 mg: 14 ml, single use via, manufacturer: Roche Pharma AG, batch number: H0309H02). The trial period was 99 days (blood samples for PK were collected 99 days after infusion). Serum concentrations were determined using a validated assay. PK parameters were calculated using a non-compartmental model and analyzed statistically. Anti-drug antibody (ADA)-positive samples were further tested for the presence of neutralization antibody detection (NAb).

Results: A total of 137 healthy subjects were administrated. The subjects were randomized 1:1 to receive QL1209 or Perjeta^® 420 mg intravenously. The geometric mean ratio (GMRs) for QL1209 versus Perjeta^® are 104.14%, 104.09%, and 110.59% for C_max, AUC_0-t, and AUC_0-∞, respectively, and their 90% confidence interval (CIs) all fell within the predefined bioequivalence margin 80.00–125%. The incidence of drug-related adverse events was 95.6% and 95.5% in the QL1209 and Perjeta^® groups, respectively, also comparable between the two groups.

Conclusion: The results of this comparative clinical pharmacology study demonstrated the PK similarity of QL1209 (420 mg: 14 ml) and Perjeta^® (420 mg: 14 ml) and there was no significant difference in safety and immunogenicity between QL1209 and Perjeta^® manufactured by Roche Pharma AG.

Antibody-Incorporated Nanomedicines for Cancer Therapy

Antibody-based cancer therapy, one of the most significant therapeutic strategies, has achieved considerable success and progress over the past decades. Nevertheless, obstacles including limited tumor penetration, short circulation half-lives, undesired immunogenicity, and off-target side effects remain to be overcome for the antibody-based cancer treatment. Owing to the rapid development of nanotechnology, antibody-containing nanomedicines that have been extensively explored to overcome these obstacles have already demonstrated enhanced anticancer efficacy and clinical translation potential. This review intends to offer an overview of the advancements of antibody-incorporated nanoparticulate systems in cancer treatment, together with the nontrivial challenges faced by these next-generation nanomedicines. Diverse strategies of antibody immobilization, formats of antibodies, types of cancer-associated antigens, and anticancer mechanisms of antibody-containing nanomedicines are provided and discussed in this review, with an emphasis on the latest applications. The current limitations and future research directions on antibody-containing nanomedicines are also discussed from different perspectives to provide new insights into the construction of anticancer nanomedicines.

Rare ocular toxicity induced by pertuzumab/QL1209 in healthy chinese subjects: case reports and whole-exome sequencing analysis

Pertuzumab is a recombinant anti-HER2 humanized monoclonal antibody widely used for the adjuvant treatment of HER2-positive breast cancer. Its safety is well established with the most common adverse effects being diarrhea and rash. To our knowledge, severe pertuzumab-induced ocular adverse events have never been reported. Herein, we describe several cases of pertuzumab/QL1209 (pertuzumab biosimilar)-induced blurred vision in healthy Chinese male subjects after a single injection of 420 mg pertuzumab/QL1209. Persistent optic nerve damage and vision loss occurred in the most severe case even after ophthalmic treatment. We conducted whole-exome sequencing (WES) of DNA samples from 5 cases and 13 controls to analyze the potential genetic factors and identified some associated variants (rs80303690 in RBM24, rs117375173 in CASR, rs1805097 in IRS2, and rs1227049 in CDH23). Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms gene enrichment analyses were carried out for differentially expressed genes clustered in the PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways, which were exactly activated by HER2 phosphorylation. In summary, this is the first report describing the occurrence of ocular toxicity induced by pertuzumab in the Chinese population and exploring the possible genetic mechanisms. These findings could provide evidence for clinicians to raise concerns about the risk of ocular toxicity with the clinical use of pertuzumab.

Multiplex Droplet Digital PCR Assay for Detection of MET and HER2 Genes Amplification in Non-Small Cell Lung Cancer

Non-small-cell lung cancer (NSCLC), a subtype of lung cancer, remains one of the most common tumors with a high mortality and morbidity rate. Numerous targeted drugs were implemented or are now developed for the treatment of NSCLC. Two genes, HER2 and MET, are among targets for these specific therapeutic agents. Alterations in HER2 and MET could lead to primary or acquired resistance to commonly used anti-EGFR drugs. Using current methods for detecting HER2 and MET amplifications is time and labor-consuming; alternative methods are required for HER2 and MET testing. We developed the first multiplex droplet digital PCR assay for the simultaneous detection of MET and HER2 amplification in NSCLC samples. The suitability of qPCR was assessed for the optimization of multiplex ddPCR. The optimal elongation temperature, reference genes for DNA quantification, and amplicon length were selected. The developed ddPCR was validated on control samples with various DNA concentrations and ratios of MET and HER2 genes. Using ddPCR, 436 EGFR-negative NSCLC samples were analyzed. Among the tested samples, five specimens (1.15%) showed a higher ratio of MET, and six samples (1.38%) showed a higher ratio of HER2. The reported multiplex ddPCR assay could be used for the routine screening of MET and HER2 amplification in NSCLC samples.

BCL2A1 regulates Canady Helios Cold Plasma-induced cell death in triple-negative breast cancer

Breast cancer is the leading cause of cancer death among women. Triple-negative breast cancer (TNBC) has a poor prognosis and frequently relapses early compared with other subtypes. The Cold Atmospheric Plasma (CAP) is a promising therapy for prognostically poor breast cancer such as TNBC. The Canady Helios Cold Plasma (CHCP) induces cell death in the TNBC cell line without thermal damage, however, the mechanism of cell death by CAP treatment is ambiguous and the mechanism of resistance to cell death in some subset of cells has not been addressed. We investigate the expression profile of 48 apoptotic and 35 oxidative gene markers after CHCP treatment in six different types of breast cancer cell lines including luminal A (ER+ PR+/-HER2-), luminal B (ER+PR+/-HER2+), (ER-PR-HER2+), basal-like: ER-PR-HER2- cells were tested with CHCP at different power settings and at 4 different incubation time. The expression levels of the gene markers were determined at 4 different intervals after the treatment. The protein expression of BCL2A1 was only induced after CHCP treatment in TNBC cell lines (p < 0.01), whereas the HER2-positive and ER, PR positive cell lines showed little or no expression of BCL2A1. The BCL2A1 and TNF-alpha expression levels showed a significant correlation within TNBC cell lines (p < 0.01). Silencing BCL2A1 mRNA by siRNA increased the potency of the CHCP treatment. A Combination of CHCP and CPI203, a BET bromodomain inhibitor, and a BCL2A1 antagonist increased the CHCP-induced cell death (p < 0.05). Our results revealed that BCL2A1 is a key gene for resistance during CHCP induced cell death. This resistance in TNBCs could be reversed with a combination of siRNA or BCL2A1 antagonist-CHCP therapy.

Epitope Mapping of an Anti-HER2 Monoclonal Antibody (H2Mab-181) Using Enzyme-Linked Immunosorbent Assay

Human epidermal growth factor receptor 2 (HER2) is a type I transmembrane 185 kDa protein expressed in various types of normal or cancer cells. Overexpression of HER2 is found in many cancers and is related to cell proliferation, differentiation, and migration. We recently developed a novel anti-HER2 monoclonal antibody, H₂Mab-181, by immunizing mice with the purified recombinant extracellular domain of HER2. H₂Mab-181 can specifically and sensitively detect HER2 not only in flow cytometry and Western blotting for gastric cancer cell lines, but also in immunohistochemical analyses for gastric cancer tissues. In this study, we analyzed the binding epitope of H₂Mab-181 to HER2 using enzyme-linked immunosorbent assay (ELISA). Results showed that the H₂Mab-181 epitope was determined to be Gly383, Asp384, Ala386, Asn388, and Pro391 by ELISA.

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.

Bone marrow ribonucleotide reductase mRNA levels and methylation status as prognostic factors in patients with myelodysplastic syndrome treated with 5-Azacytidine

Ribonucleotide Reductase (RNR) is a two-subunit (RRM1, RRM2) enzyme, responsible for the conversion of ribonucleotides to deoxyribonucleotides required for DNA replication. To evaluate RNR as a biomarker of response to 5-azacytidine, we measured RNR mRNA levels by a quantitative real-time PCR in bone marrow samples of 98 patients with myelodysplastic syndrome (MDS) treated with 5-azacytidine with parallel quantification of the gene promoter's methylation. Patients with low RRM1 levels had a high RRM1 methylation status (p = 0.005) and a better response to treatment with 5-azacytidine (p = 0.019). A next-generation sequencing for genes of interest in MDS was also carried out in a subset of 61 samples. Splicing factor mutations were correlated with lower RRM1 mRNA levels (p = 0.044). Our results suggest that the expression of RNR is correlated with clinical outcomes, thus its expression could be used as a prognostic factor for response to 5-azacytidine and a possible therapeutic target in MDS.

Development of a Novel Anti-HER2 Monoclonal Antibody H2Mab-181 for Gastric Cancer

Human epidermal growth factor receptor 2 (HER2) is a type I transmembrane 185 kDa protein. HER2 is expressed in a variety of normal tissue types and cancer cells. HER2 is associated with cell proliferation, differentiation, and migration. The overexpression of HER2 has been observed in a number of cancers, including breast and gastric cancers. Gastric cancer is one of the most common cancers worldwide, with an annual case rate of ∼1 million people diagnosed with the disease. Trastuzumab is a humanized anti-HER2 monoclonal antibody (mAb) that has been utilized in gastric cancer therapy. In this study, we have developed a novel anti-HER2 mAb, H₂Mab-181 (IgG₁, kappa), through the immunization of mice with a purified recombinant extracellular domain of HER2. H₂Mab-181 can specifically and sensitively detect HER2 in both flow cytometry and Western blot applications in gastric cancer cell lines and can also be utilized in immunohistochemical analyses of gastric cancer tissues. Together, H₂Mab-181 could be useful for the diagnosis and therapy in gastric cancers.

Precision Medicine in Oncology: A Review of Multi-Tumor Actionable Molecular Targets with an Emphasis on Non-Small Cell Lung Cancer

Precision medicine is essential for the modern care of a patient with cancer. Comprehensive molecular profiling of the tumor itself is necessary to determine the presence or absence of certain targetable abnormalities or biomarkers. In particular, lung cancer is a disease for which targetable genomic alterations will soon guide therapy in the majority of cases. In this comprehensive review of solid tumor-based biomarkers, we describe the genomic alterations for which targeted agents have been approved by the United States Food and Drug Administration (FDA). While focusing on alterations leading to approvals in a tumor-agnostic fashion (MSI-h, TMB-h, NTRK) and on those alterations with approvals in multiple malignancies (BRAF, ERBB2, RET, BRCA, PD-L1), we also describe several biomarkers or indications that are likely to lead to an approved drug in the near future (e.g., KRAS G12C, PD-L1 amplification, HER2 overexpression in colon cancer, HER2 mutations in lung cancer). Finally, we detail the current landscape of additional actionable alterations (EGFR, ALK, ROS1, MET) in lung cancer, a biomarker-rich malignancy that has greatly benefitted from the precision oncology revolution.

Pathologic Complete Response Rates After Neoadjuvant Pertuzumab and Trastuzumab with Chemotherapy in Early Stage HER2-Positive Breast Cancer - Increasing Rates of Breast Conserving Surgery: A Real-World Experience

Purpose: The neoadjuvant use of pertuzumab and trastuzumab with chemotherapy improves the pathologic complete response (pCR) in early HER2+ breast cancer. The aim of this study was to determine the pCR rate obtained with dual HER2 blockade in routine clinical practice. The secondary and tertiary objective was to investigate the impact of neoadjuvant systemic therapy (NST) on performing breast-conserving surgery and survival data.

Methods: This was a multicentre, retrospective, observational study in patients with stage II and III HER2+ early breast cancer who received pertuzumab and trastuzumab-based NST. Data were collected from patients’ medical records.

Results: Eighty-two patients were included in the study treated in 8 cancer centers in Hungary between March 2015 and January 2020. The study included women with a median age of 50.3 years. The majority of the patients (95%) received a sequence of anthracycline-based chemotherapy followed by docetaxel. pCR was achieved in 54% of the cases. As a result of NST a significant increase of conservative breast surgeries (33% vs. 3.6% planned, p = 0.0001) was observed. Ki67 expression and neutrophil-to-lymphocyte ratio (NLR) significantly predicted pCR. None of the variables were independent predictors of DFS.

Conclusion: The pCR rate achieved in our study demonstrates the reproducibility of trial data in a real-world population. The rate of breast-conserving surgery was significantly increased.

Cost-effectiveness of GLP-1 receptor agonists versus insulin for the treatment of type 2 diabetes: a real-world study and systematic review

BACKGROUND

To conduct a real-word-study-based cost-effectiveness analysis of a GLP-1 receptor agonist (GLP-1RA) versus insulin among type 2 diabetes patients requiring intensified injection therapy and a systematic review of cost-effectiveness studies of GLP-1RAs versus insulin.

METHODS

Individual-level analyses incorporating real-world effectiveness and cost data were conducted for a cohort of 1022 propensity-score-matched pairs of GLP-1RA and insulin users from Taiwan's National Health Insurance Research Database, 2007-2016. Study outcomes included the number needed to treat (NNT) to prevent one case of clinical events, healthcare costs, and cost per case of event prevented. Costs were in 2019 US dollars. Analyses were performed from a third-party payer and healthcare sector perspectives. Structured systematic review procedures were conducted to synthesize updated evidence on the cost-effectiveness of GLP-1RAs versus insulin.

RESULTS

Over a mean follow-up of 2.3 years, the NNT using a GLP-1RA versus insulin to prevent one case of all-cause mortality and hospitalized hypoglycemia was 57 and 30, respectively. Using GLP-1RAs instead of insulin cost US$54,851 and US$29,115 per case of all-cause mortality and hospitalized hypoglycemia prevented, respectively, from the payer perspective, and saved US$19,391 and US$10,293, respectively, from the healthcare sector perspective. Sensitivity analyses showed that the probability of using GLP-1RAs versus insulin being cost-effective for preventing one case of all-cause mortality or hospitalized hypoglycemia ranged from 60 to 100%. The systematic review revealed a cost-effective profile of using GLP-1RAs versus insulin.

CONCLUSIONS

Using GLP-1RAs versus insulin for type 2 diabetes patients requiring intensified injection therapy in clinical practice is cost-effective.

Survival outcomes in patients with human epidermal growth factor receptor 2 positive metastatic breast cancer administered a therapy following trastuzumab emtansine treatment

Since 2013, trastuzumab emtansine (T-DM1) has been widely used in Japan to treat patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) who were previously administered trastuzumab and a taxane. However, there is no information about the treatment outcomes after exposure to T-DM1 in Japanese patients with HER2-positive MBC. In this study, we aimed to describe the survival outcomes of patients with HER2-positive MBC who received a treatment following T-DM1 and clarify the predictive factors of their prognosis.We retrospectively identified patients with HER2-positive MBC who received T-DM1 between April 1, 2014, and December 31, 2018, at the National Cancer Center Hospital, and focused on the population that received another line of therapy following T-DM1 discontinuation.Thirty patients were available for the outcome analysis. Median progression-free survival (PFS) of the first subsequent therapy was 6.0 months [95% confidence interval (95% CI) 4.1-6.4], whereas the median overall survival (OS) from the first subsequent therapy was 20.6 months (95% CI 13.5 months to not reached). We divided the patients into 2 groups according to their PFS with T-DM1 treatment and compared their PFS with the subsequent therapy. The results revealed a significant difference in the median PFS with the first subsequent treatment between patients with the PFS of less than and more than 3 months [5.1 (95% CI 1.7-6.2) vs 6.2 (95% CI 4.0-11.3) months, P = .03].This is the first study to evaluate the survival outcomes of post-T-DM1 therapy in Japanese patients with HER2-positive MBC. A short PFS with T-DM1 might affect the PFS with a treatment after T-DM1.

A novel HER2-targeting antibody 5G9 identified by large-scale trastuzumab-based screening exhibits potent synergistic antitumor activity

Background

Pertuzumab is currently used in combination with trastuzumab as the first-line treatment for HER2-positive metastatic breast cancer. However, pertuzumab was originally developed independently from trastuzumab and was later incidentally found to have synergistic efficacy when combined with trastuzumab, it remains to be seen whether a more potent synergistic efficacy partner exists for trastuzumab.

Methods

A trastuzumab-based functional assay was used to screen anti-HER2 antibodies harboring trastuzumab-synergistic antitumor activity. The lead candidate 5G9, in combination with trastuzumab, was further characterized for its bioactivities in cell proliferation, cell apoptosis, antigen-antibody endocytosis and HER2-mediated cell signaling pathway blocking. Finally, animal models were used to evaluate the in vivo synergistic antitumor efficacy of 5G9 in combination with trastuzumab.

Findings

Compared to pertuzumab, 5G9 demonstrated more potent synergistic cell growth inhibitory activity when combined with trastuzumab (85% vs. 55%, P<0.001). In addition, 5G9 exhibited a higher internalization rate than pertuzumab (20% vs. 9%, P<0.05), and was able to further synergize with trastuzumab to promote antigen-antibody endocytosis. The internalization rate of the combination of 5G9 and trastuzumab was higher than that of pertuzumab and trastuzumab (35% vs. 14%, P<0.001). In vivo animal studies demonstrated that 5G9 in combination with trastuzumab showed more potent synergistic antitumor efficacy than the combination of pertuzumab and trastuzumab.

Interpretation

5G9, together with trastuzumab, may provide a potential opportunity for more efficacious treatment of HER2-positive cancers.

Funding

National Natural Science Foundation of China; State Key Laboratory of Analytical Chemistry for Life Science.

Immune checkpoint inhibitors: Key trials and an emerging role in breast cancer

This review focuses on immune checkpoint inhibitors - immunomodulatory agents that aim to relieve tumour-mediated immune-cell suppression. Immune checkpoint proteins can be expressed on the tumour-cell or immune-cell populations. Immune checkpoint proteins dampen the immune response by inactivating immune cells capable of tumour destruction. Blockade of immune checkpoints has shown impressive results in a range of solid cancers, particularly melanoma and non-small cell lung cancer. The potential benefit of this class of drugs is widespread across most cancer types and an unprecedented number of clinical studies are underway to examine the benefit of these agents. The aims of this review are to: provide an overview of the key early immune checkpoint inhibitor trials involving drugs targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) in multiple disease types; provide an overview of emerging therapies aimed at these targets; and provide a detailed exploration of the status of immune checkpoint inhibitors in breast cancer.

Anti-HER2 therapy for breast cancer in older patients

Older patients now form between 30 and 40% of breast cancer (BC) patients. Managing older patients with BC is particularly challenging due to the limited availability of high-quality evidence. In this review we discuss the available evidence on the efficacy and safety of anti-HER2 agents in older patients with HER2-positive BC is presented, with a particular look at the latest results of promising new agents such trastuzumab-deruxtecan. The data suggest that older patients can expect similar efficacy when using standard regimens, with higher toxicity, particular cardiac toxicity and diarrhea. Anti-HER2 agents should thus be used in most older patients most as per standard of care as long as adequate follow-up is available to manage toxicities.

A novel anti-HER2 antibody GB235 reverses Trastuzumab resistance in HER2-expressing tumor cells in vitro and in vivo

HER2 overexpression is frequently associated with tumor metastasis and poor prognosis of breast cancer. More evidence indicates that HER3 is involved in HER2-resistant therapies. Combination treatments with two or more different monoclonal antibodies are a promising strategy to overcome resistance to HER2 therapies. We presented a novel fully human HER2-targeted monoclonal antibody, GB235, screened from a phage-display library against the HER2 antigen. GB235 in combination with Trastuzumab overcomes resistance in HER2-positive tumors and results in more sustained inhibition of tumor growth over time. The competition binding assay showed that the epitopes of GB235 do not overlap with those of Pertuzumab and Trastuzumab on HER2. Further HER2 mutagenesis results revealed that the binding epitopes of GB235 were located in the domain III of HER2. The mechanism of action of GB235 in blocking HER2-driven tumors is different from the mechanisms of Trastuzumab or Pertuzumab. GB235 does not affect the heterodimerization of HER2 and HER3, whereas the GB235 combined treatment with Trastuzumab significantly inhibited heregulin-induced HER3 phosphorylation and downstream signaling. Moreover, GB235 in combination with Trastuzumab reversed the resistance to heregulin-induced proliferation in HER2-overexpressing cancer cell lines. GB235 combined with Trastuzumab treatment in xenograft models resulted in improved antitumor activity. Complete tumor suppression was observed in the HER2-positive NCI-N87 xenograft model treated with the combination treatment with GB235 and Trastuzumab. In a Trastuzumab-resistant patient-derived tumor xenograft model GA0060, GB235 plus Trastuzumab reversed the resistance to Trastuzumab monotherapy. Because GB235 showed a different working mechanism with Pertuzumab and Trastuzumab, these agents can be considered complementary therapy against HER2 overexpression tumors.

Recent advances and optimal management of human epidermal growth factor receptor-2-positive early-stage breast cancer

With the introduction of anthracycline-based regimens, 5-year survival rates have significantly improved in patients with early-stage breast cancer. With the addition of trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor-2 (HER2), improvements in overall survival have been observed among patients with advanced HER2-positive disease. Subsequently, lapatinib, an orally bioavailable small molecule dual HER2- and EGFR/HER1-specific tyrosine kinase inhibitor, received Food and Drug Administration (FDA) approval in combination with capecitabine for patients with advanced HER2+ breast cancer. Then, pertuzumab in 2012 and ado-trastuzumab emtansine in 2013 were approved in the US and elsewhere based on evidence showing an improvement in survival outcomes in patients with mostly trastuzumab naïve or trastuzumab-exposed metastatic disease. The FDA also approved 1 year of extended adjuvant neratinib after chemotherapy and a year of trastuzumab for HER2-positive breast cancer on the basis of the ExteNET trial. The clinical benefit demonstrated by those drugs in advanced disease has triggered several adjuvant and neoadjuvant trials testing them in combination with chemotherapy, but also without conventional chemotherapy, using single or dual HER2-targeting drugs. In this article, we review the current data on the therapeutic management of HER2-positive early-stage breast cancer in the adjuvant and neoadjuvant setting. We also review the data the efficacy and safety of anthracycline-based and nonanthracycline-based adjuvant chemotherapy regimens combined with trastuzumab, and optimum chemotherapy regimens in small HER2-positive tumors.

Oncogenic signaling pathways associated with immune evasion and resistance to immune checkpoint inhibitors in cancer

Immune checkpoint inhibitors (ICIs) are novel class of anti-cancer drugs that exhibit significant therapeutic effects even in patients with advanced-stage cancer. However, the efficacy of ICIs is limited due to resistance. Therefore, appropriate biomarkers to select patients who are likely to respond to these drugs as well as combination therapy to overcome the resistance are urgently necessary. Cancer is caused by various genetic alterations that lead to abnormalities in oncogenic signaling pathways. The aberrant oncogenic signaling pathways serve as not only prognostic and predictive biomarkers, but also targets for molecularly targeted therapy. Growing evidence shows that the aberrant oncogenic signaling pathways in cancer cells facilitate the resistance to ICIs by modulating the regulation of immune checkpoint and cancer immune surveillance. Indeed, it has been demonstrated that some molecular targeted therapies significantly improve the efficacy of ICIs in preclinical and clinical studies. In this review, we highlighted several oncogenic signaling pathways including receptor tyrosine kinases (RTKs), MAPK, PI3K-AKT-mTOR, JAK-STAT, Hippo, and Wnt pathways, and summarized the recent findings of the mechanisms underlying the regulation of cancer immunity and the ICI resistance induced by these aberrant oncogenic signaling pathways in cancer cells. Moreover, we discussed potential combination therapies with ICIs and molecularly targeted drugs to overcome the resistance and increase the efficacy of ICIs.

Cost-Effectiveness Analysis of Adjuvant Neratinib Following Trastuzumab in Early-Stage HER2-Positive Breast Cancer

BACKGROUND

Disease-free survival (DFS) in early-stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer is significantly greater with the addition of neratinib after adjuvant trastuzumab versus no additional therapy. However, it remains uncertain whether these survival gains represent good value for the money, given the substantial cost of neratinib.

OBJECTIVE

To evaluate clinical and economic implications of adding neratinib after adjuvant trastuzumab based on results from the phase III ExteNET trial.

METHODS

A 3-state Markov model was developed to estimate the cost-effectiveness of neratinib for women with early-stage (I-III) HER2-positive breast cancer. Five-year recurrence rates were derived from the ExteNET trial. Mortality and recurrence rates after 5 years were derived from the HERceptin Adjuvant (HERA) trial. Outcomes included life-years, quality-adjusted life-years (QALYs), and direct medical expenditures. The analysis was performed from a payer perspective over a lifetime horizon. One-way sensitivity and probabilistic analyses were conducted to evaluate uncertainty.

RESULTS

Total cost of neratinib following adjuvant trastuzumab was $317,619 versus $152,812 for adjuvant trastuzumab alone. A gain of 0.4 QALYs (15.7 vs. 15.3) and 0.1 years of projected life expectancy (18.3 vs. 18.2) favored neratinib after trastuzumab versus trastuzumab alone. The neratinib cost per QALY gained was $416,106. At standard willingness-to-pay thresholds of $50,000, $100,000, and $200,000 per QALY gained, neratinib has a probability of 2.8%, 16.7%, and 33.9% of cost-effectiveness, respectively. The cost per QALY gained in a scenario analysis only including patients with hormone-receptor positive disease was $275,311.

CONCLUSIONS

Based on 5-year data from ExteNET, neratinib following adjuvant trastuzumab is not projected to be cost-effective, even among those patients shown to derive the greatest clinical benefit. Future analyses should reassess the cost-effectiveness associated with neratinib treatment as trial data mature.

DISCLOSURES

No outside funding supported this study. Roth reports consulting fees from Genentech. Steuten reports grants from AstraZeneca, EMD Serono, and Genomic Health, along with personal fees from Agendia, unrelated to this study. The other authors have no conflicts of interest in connection with this study.

Antibody-drug conjugates for cancer

Antibody-drug conjugates (ADCs) are immunoconjugates comprised of a monoclonal antibody tethered to a cytotoxic drug (known as the payload) via a chemical linker. The ADC is designed to selectively deliver the ultratoxic payload directly to the target cancer cells. To date, five ADCs have received market approval and over 100 are being investigated in various stages of clinical development. In this Therapeutics paper, we review recent clinical experience with the approved ADCs and other promising late-stage candidates on the horizon, following an overview of the biology and chemistry of ADCs and how the individual components of an ADC (antibody [or target], linker and conjugation chemistry, and cytotoxic payload) influence its activity. We briefly discuss opportunities for enhancing ADC efficacy, drug resistance, and future perspectives for this novel antibody-based molecular platform, which has great potential to make a paradigm shift in cancer chemotherapy.

Bp-Bs, a Novel T-cell Engaging Bispecific Antibody with Biparatopic Her2 Binding, Has Potent Anti-tumor Activities

Patients with Human epidermal growth factor receptor type 2 (Her2) overexpression are associated with aggressive tumor growth and poor clinical outcomes. Bispecific antibodies targeting Her2 have recently exhibited potent effects on Her2 signal inhibition. In this study, a novel biparatopic anti-Her2 bispecific antibody (Bp-Bs) was constructed by linking a single anti-CD3 Fab with two different anti-Her2 single-domain antibodies targeting non-overlapping epitopes of Her2. The Bp-Bs demonstrated strong binding on Her2-positive cells and potent cytotoxicity on Her2-positive tumor cells, even Her2-low expression cells, suggesting that biparatopic bispecific antibodies may have improved therapeutic benefits on broad Her2 patient populations.

Prevalence and role of HER2 mutations in cancer

HER2 activating mutations act as oncogenic drivers in various cancer types. In the clinic, they can be identified by next generation sequencing (NGS) in either tumor biopsies or circulating cell-free DNA (cfDNA). Preclinical data indicate that HER2 "hot spot" mutations are constitutively active, have transforming capacity in vitro and in vivo and show variable sensitivity to anti-HER2 based therapies. Recent clinical trials also revealed activity of HER2-targeted drugs against a variety of tumors harboring HER2 mutations. Here, we review the prevalence and type of HER2 mutations identified in different human cancers, their biochemical and biological characterization, and their sensitivity to anti HER2-based therapies in both preclinical and clinical settings.

Anti-Diarrheal Drug Repositioning in Tumour Cell Cytotoxicity

BACKGROUND

Drug repositioning is becoming an ideal strategy to select new anticancer drugs. In particular, drugs treating the side effects of chemotherapy are the best candidates.

OBJECTIVE

In this present work, we undertook the evaluation of anti-tumour activity of two anti-diarrheal drugs (nifuroxazide and rifaximin).

METHODS

Anti-proliferative effect against breast cancer cells (MDA-MB-231, MCF-7 and T47D) was assessed by MTT analysis, the Brdu incorporation, mitochondrial permeability and caspase-3 activity.

RESULTS

Both the drugs displayed cytotoxic effects on MCF-7, T47D and MDA-MB-231 cells. The lowest IC50 values were obtained on MCF-7 cells after 24, 48 and 72 hours of treatment while T47D and MDA-MB-231 were more resistant. The IC50 values on T47D and MDA-MB-231 cells became significantly low after 72 hours of treatment showing a late cytotoxicity effect especially of nifuroxazide but still less important than that of MCF-7 cells. According to the IC50 values, the non-tumour cell line HEK293 seems to be less sensitive to cytotoxicity especially against rifaximin. Both the drugs have shown an accumulation of rhodamine 123 as a function of the rise of their concentrations while the Brdu incorporation decreased. Despite the absence of a significant difference in the cell cycle between the treated and non-treated MCF-7 cells, the caspase-3 activity increased with the drug concentrations rise suggesting an apoptotic effect.

CONCLUSION

Nifuroxazide and rifaximin are used to overcome the diarrheal side effect of anticancer drugs. However, they have shown to be anti-tumour drugs which make them potential dual effective drugs against cancer and the side effects of chemotherapy.

Comprehensive genomic variation profiling of cervical intraepithelial neoplasia and cervical cancer identifies potential targets for cervical cancer early warning

Background

To better understand the pathogenesis of cervical cancer (CC), we systematically analysed the genomic variation and human papillomavirus (HPV) integration profiles of cervical intraepithelial neoplasia (CIN) and CC.

Methods

We performed whole-genome sequencing or whole-exome sequencing of 102 tumour-normal pairs and human papillomavirus probe capture sequencing of 45 CCs, 44 CIN samples and 25 normal cervical samples, and constructed strict integrated workflow of genomic analysis.

Results

Mutational analysis identified eight significantly mutated genes in CC including four genes (FAT1, MLL3, MLL2 and FADD), which have not previously been reported in CC. Targetable alterations were identified in 55.9% of patients. In addition, HPV integration breakpoints occurred in 97.8% of the CC samples, 70.5% of the CIN samples and 42.8% of the normal cervical samples with HPV infection. Integrations of high-risk HPV strains in CCs, including HPV16, 18, 33 and 58, also occurred in the CIN samples. Moreover, gene mutations were detected in 52% of the CIN specimens, and 54.8% of these mutations occurred in genes that also mutated in CCs.

Conclusion

Our results lay the foundation for a deep understanding of the molecular mechanisms and finding new diagnostic and therapeutic targets of CC.

Pertuzumab, trastuzumab and taxane-based treatment for visceral organ metastatic, trastuzumab-naïve breast cancer: real-life practice outcomes

PURPOSE

In this study, we aimed to describe the real-life practice outcomes of pertuzumab-trastuzumab-taxane (PTT) combination in visceral organ metastatic, trastuzumab-naive breast cancer (BC) patients.

METHODS

This study was conducted by Turkish Oncology Group and included 317 patients' data from 36 centers.

RESULTS

Median age was 51 (22-82). Median PFS was 28.5 months, while median OS was 40.3 months. Patients with brain metastases (n: 13, 4.1%) had worse PFS (16.8 m vs. 28.5 m; p = 0.002) and OS (26.7 m vs. 40.3 m; p = 0.009). Patients older than 65 years of age (n: 42, 13.2%) had significantly lower OS results (19.8 m vs. 40.3 m; p = 0.01). Two hundred sixty-eight patients (86.7%) received docetaxel while 37 patients (11.7%) received paclitaxel. PFS and OS were similar between taxane groups. In eight patients (2.5%), 5-40% ejection fraction decrement from baseline was detected without any clinical sign of heart failure.

CONCLUSIONS

Our RLP trial included only visceral metastatic, trastuzumab-naïve BC patients including cases with brain involvement who received PTT combination in the first-line treatment. Regardless of negative prognostic characteristics, our results are in parallel with pivotal trial. Further strategies for brain metastasis should be developed to improve outcomes despite encouraging results with PTT treatment. Taxane selection can be personalized and endocrine maintenance may further improve outcomes after taxanes were discontinued. To our knowledge, this is the largest scale real-life clinical practice study of pertuzumab-trastuzumab-taxane therapy to date.

Synergistic Targeting HER2 and EGFR with Bivalent Aptamer-siRNA Chimera Efficiently Inhibits HER2-Positive Tumor Growth

HER2 overexpression is identified on 20–30% breast cancer and other cancers at different levels. Although HER2 targeted monoclonal antibody combined with chemical drugs has shown improved outcomes in HER2 expressing patients, drug resistance and toxicity have limited their efficacy. To overcome drug resistance, cotargeting  multiple HER receptors was proven to be effective. EGFR/HER2 dimerization can active PI3K/AKT pathway, and resistance to HER2-targeted drugs is associated with upregulation of EGFR. Here, we developed a novel HER2/EGFR targeted nucleic acid therapeutic to address current drug limits. The new therapeutic is constructed by fusing HER2 aptamer-EGFR siRNA sense strand with HER2 aptamer-EGFR siRNA antisense strand into one molecule: a bivalent HER2 aptamer-EGFR siRNA aptamer chimera (HEH). In breast cancer cell lines, HEH can be selectively taken up into HER2 expressing cells and successfully silence EGFR gene and down regulate HER2 expression. In breast cancer xenograft models, HEH is capable of triggering cell apoptosis, decreasing HER2 and EGFR expression, and suppressing tumor growth. The therapeutic efficacy of HEH is superior to HER2 aptamer only, which suggests that HEH has synergistic effect by targeting HER2 and EGFR. This study demonstrated that HEH has great potential as a new HER2 targeted drug to address toxicity and resistance of current drugs and may provide a cure for many HER2 positive cancers.

Targeted Therapies Against Growth Factor Signaling in Breast Cancer

Breast cancer is the most prevalent female malignancy throughout the world. Conventional treatment strategies for breast cancer consist of chemotherapy, radiation, surgery, chemoradiation, hormone therapy, and targeted therapies. Among them, targeted therapies show advantages to reduce cost and toxicity for being possible for individualized treatments based on the intrinsic subtypes of breast cancer. With deeper understanding of key signaling pathways concerning tumor growth and survival, growth factor-controlled signaling pathways are frequently dysregulated in the development and progression of breast cancer. Thus, targeted therapies against growth factor-mediated signaling pathways have been shown to have promising efficacy in both preclinical animal models and human clinical trials. In this chapter, we will briefly introduce inhibitors and monoclonal antibodies that target the main growth factor-modulated scenarios including epidermal growth factor receptor (EGFR), transforming growth factor beta (TGF-β), insulin-like growth factor 1 receptor (IGF1R), and fibroblast growth factor receptor (FGFR) signaling pathways in breast cancer therapy.