First-in-human phase 1 study of margetuximab (MGAH22), an Fc-modified chimeric monoclonal antibody, in patients with HER2-positive advanced solid tumors

Advances in Human Epidermal Growth Factor Receptor 2-Targeted Therapy in Upper Gastrointestinal Cancers

The Trastuzumab for Gastric Cancer (ToGA) trial marked a pivotal moment in the adoption of trastuzumab for treating advanced human epidermal growth factor receptor 2 (HER2)-positive esophagogastric (EG) cancer. The KEYNOTE-811 trial brought to light the synergistic effect of immune modulation and HER2 targeting. Additionally, the emergence of trastuzumab deruxtecan (T-DXd) highlighted the potential of new pharmaceutical technologies to extend response, particularly for patients who have advanced beyond initial HER2-targeted therapies. This review aims to navigate through both the successes and challenges encountered historically, as well as promising current trials on innovative and transformative therapeutic strategies, including promising first-in-class and novel first-in-human agents.

Recent Progress in Treatment for HER2-Positive Advanced Gastric Cancer

Human epidermal receptor (HER) 2-positive advanced gastric cancer is one of the major subtypes of gastric cancer, accounting for ~20% of all cases. Although combination therapy with trastuzumab and chemotherapy provides meaningful survival benefit, clinical trials targeting HER2 have failed to demonstrate clinical benefits in first- or subsequent-line treatment. Trastuzumab deruxtecan, an antibody-drug conjugate, has shown positive results even in later-line treatment and has become new standard treatment. In first-line therapy, combination therapy with pembrolizumab and trastuzumab plus chemotherapy demonstrated a dramatic response rate. Therefore, the FDA rapidly approved it without waiting for the results of survival time. The emergence of combination therapy including immunotherapy with HER2-targeting agents and the development of HER2 targeting agents with or without immunotherapy have been advancing for treating HER2-positive gastric cancer. In this review, we will discuss the current status of treatment development and future perspectives for HER2-positive gastric cancer.

HER2+ advanced gastric cancer: Current state and opportunities (Review)

Human epidermal growth factor receptor 2 (HER2)+ gastric cancer (GC) is a distinct subtype of GC, accounting for 10‑20% of all cases of GC. Although the development of the anti‑HER2 monoclonal antibody trastuzumab has markedly improved response rates and prognosis of patients with HER2+ advanced GC (AGC), drug resistance remains a considerable challenge. Therefore, dynamic monitoring of HER2 expression levels can facilitate the identification of patients who may benefit from targeted therapy. Besides trastuzumab, DS‑8201 and RC48 have been applied in the treatment of HER2+ AGC, and several novel anti‑HER2 therapies are undergoing preclinical/clinical trials. At present, combination immunotherapy with anti‑HER2 agents is used as the first‑line treatment of this disease subtype. New promising approaches such as chimeric antigen receptor T‑cell immunotherapy and cancer vaccines are also being investigated for their potential to improve clinical outcomes. The current review provides new insights that will guide the future application of anti‑HER2 therapy by summarizing research progress on targeted therapy drugs for HER2+ AGC and combination treatments.

Management of patients with advanced-stage HER2-positive breast cancer: current evidence and future perspectives

Amplification and/or overexpression of ERBB2, the gene encoding HER2, can be found in 15-20% of invasive breast cancers and is associated with an aggressive phenotype and poor clinical outcomes. Relentless research efforts in molecular biology and drug development have led to the implementation of several HER2-targeted therapies, including monoclonal antibodies, tyrosine-kinase inhibitors and antibody-drug conjugates, constituting one of the best examples of bench-to-bedside translation in oncology. Each individual drug class has improved patient outcomes and, importantly, the combinatorial and sequential use of different HER2-targeted therapies has increased cure rates in the early stage disease setting and substantially prolonged survival for patients with advanced-stage disease. In this Review, we describe key steps in the development of the modern paradigm for the treatment of HER2-positive advanced-stage breast cancer, including selecting and sequencing new-generation HER2-targeted therapies, and summarize efficacy and safety outcomes from pivotal studies. We then outline the factors that are currently known to be related to resistance to HER2-targeted therapies, such as HER2 intratumoural heterogeneity, activation of alternative signalling pathways and immune escape mechanisms, as well as potential strategies that might be used in the future to overcome this resistance and further improve patient outcomes.

Emerging Landscape of Targeted Therapy of Breast Cancers With Low Human Epidermal Growth Factor Receptor 2 Protein Expression

CONTEXT.—

Human epidermal growth factor receptor 2 (HER2) status in breast cancer is currently classified as negative or positive for selecting patients for anti-HER2 targeted therapy. The evolution of the HER2 status has included a new HER2-low category defined as an HER2 immunohistochemistry score of 1+ or 2+ without gene amplification. This new category opens the door to a targetable HER2-low breast cancer population for which new treatments may be effective.

OBJECTIVE.—

To review the current literature on the emerging category of breast cancers with low HER2 protein expression, including the clinical, histopathologic, and molecular features, and outline the clinical trials and best practice recommendations for identifying HER2-low-expressing breast cancers by immunohistochemistry.

DATA SOURCES.—

We conducted a literature review based on peer-reviewed original articles, review articles, regulatory communications, ongoing and past clinical trials identified through ClinicalTrials.gov, and the authors' practice experience.

CONCLUSIONS.—

The availability of new targeted therapy potentially effective for patients with breast cancers with low HER2 protein expression requires multidisciplinary recognition. In particular, pathologists need to recognize and identify this category to allow the optimal selection of patients for targeted therapy.

Impact of structural modifications of IgG antibodies on effector functions

Immunoglobulin G (IgG) antibodies are a critical component of the adaptive immune system, binding to and neutralizing pathogens and other foreign substances. Recent advances in molecular antibody biology and structural protein engineering enabled the modification of IgG antibodies to enhance their therapeutic potential. This review summarizes recent progress in both natural and engineered structural modifications of IgG antibodies, including allotypic variation, glycosylation, Fc engineering, and Fc gamma receptor binding optimization. We discuss the functional consequences of these modifications to highlight their potential for therapeutical applications.

Hormone, Targeted, and Combinational Therapies for Breast Cancers: From Humans to Dogs

Breast cancer (BC) is the most frequent cancer in women. In female dogs, canine mammary gland tumor (CMT) is also the leading neoplasm. Comparative oncology indicates similar tumor behaviors between human BCs (HBCs) and CMTs. Therefore, this review summarizes the current research in hormone and targeted therapies and describes the future prospects for HBCs and CMTs. For hormone receptor-expressing BCs, the first medical intervention is hormone therapy. Monoclonal antibodies against Her2 are proposed for the treatment of Her2+ BCs. However, the major obstacle in hormone therapy or monoclonal antibodies is drug resistance. Therefore, increasing alternatives have been developed to overcome these difficulties. We systemically reviewed publications that reported inhibitors targeting certain molecules in BC cells. The various treatment choices for humans decrease mortality in females with BC. However, the development of hormone or targeted therapies in veterinary medicine is still limited. Even though some clinical trials have been proposed, severe side effects and insufficient case numbers might restrict further explorations. This difficulty highlights the urgent need to develop updated hormone/targeted therapy or novel immunotherapies. Therefore, exploring new therapies to provide more precise use in dogs with CMTs will be the focus of future research. Furthermore, due to the similarities shared by humans and dogs, well-planned prospective clinical trials on the use of combinational or novel immunotherapies in dogs with CMTs to obtain solid results for both humans and dogs can be reasonably anticipated in the future.

Advances in HER2-Targeted Treatment for Advanced/Metastatic Urothelial Carcinoma

Urothelial carcinoma (UC) represents a common malignancy of the urinary system that can involve the kidneys, ureter, bladder, and urethra. Advanced/metastatic UC (mUC) tends to have a poor prognosis. UC ranks third in terms of human epidermal growth factor receptor 2 (HER2) overexpression among all tumors. However, multiple studies found that, unlike breast cancer, variable degrees of HER2 positivity and poor consistency between HER2 protein overexpression and gene amplification have been found. Trials involving trastuzumab, pertuzumab, lapatinib, afatinib, and neratinib have failed to prove their beneficial effect in patients with HER2-positive mUC, and a clinical trial on T-DM1 (trastuzumab emtansine) was terminated prematurely because of the adverse reactions. However, a phase II trial showed that RC48-ADC was effective. In this review, we provided an in-depth overview of the advances in the research regarding HER2-targeted therapy and the role of HER2 in mUC. Furthermore, we also discussed the prospects of potential strategies aimed at overcoming anti-HER2 resistance, and summarize the novel anti-HER2 approaches for the management of mUC used in recent clinical trials.

Exploring the clinical outcomes and safety profile of inetetamab treatment in metastatic breast cancer patients: A multicenter assessment of a Chinese-origin recombinant Anti-HER2 monoclonal antibody

BACKGROUND

Inetetamab is a novel recombinant humanized anti-HER2 monoclonal antibody. This study aimed to evaluate the efficacy and safety of inetetamab and predictive factors for response in HER2-positive metastatic breast cancer (MBC) patients.

METHODS

A cohort of HER2-positive MBC patients who received inetetamab-based therapy between June 2020 and August 2021 was evaluated. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR) and disease control rate (DCR). Adverse events (AEs) were graded according to the National Cancer Institute Common Toxicity Criteria.

RESULTS

A total of 141 patients were included in the final analysis. The median PFS of the entire cohort was 7.1 months. The median number of treatment lines administered was three. The ORR was 36.9 %, and the DCR was 80.9 %. The most frequently employed treatment strategy was inetetamab + chemotherapy (49/141, 34.8 %), followed by inetetamab + HER2-tyrosine kinase inhibitors (HER2-TKIs) + chemotherapy, inetetamab + pertuzumab + chemotherapy, inetetamab + endocrine treatment and inetetamab + HER2-TKIs. Cox multivariate analysis revealed that PFS was associated with liver metastasis (hazard ratio [HR] 2.112, 95 % confidence interval [CI] 1.334-3.343, p = 0.001), previous HER2-TKI treatment (HR 2.019, 95 % CI 1.133-3.597, p = 0.017) and estrogen receptor positivity (HR 0.587, 95 % CI 0.370-0.934, p = 0.024). The toxicity was tolerable, with neutropenia being the most common treatment-related grade 3/4 AE (14.9 %).

CONCLUSION

Inetetamab demonstrates effectiveness with a manageable safety profile, offering a promising therapeutic option for HER2-positive breast cancer patients who have shown resistance to prior anti-HER2 treatments.

The PD-1- and LAG-3-targeting bispecific molecule tebotelimab in solid tumors and hematologic cancers: a phase 1 trial

Tebotelimab, a bispecific PD-1×LAG-3 DART molecule that blocks both PD-1 and LAG-3, was investigated for clinical safety and activity in a phase 1 dose-escalation and cohort-expansion clinical trial in patients with solid tumors or hematologic malignancies and disease progression on previous treatment. Primary endpoints were safety and maximum tolerated dose of tebotelimab when administered as a single agent (n = 269) or in combination with the anti-HER2 antibody margetuximab (n = 84). Secondary endpoints included anti-tumor activity. In patients with advanced cancer treated with tebotelimab monotherapy, 68% (184/269) experienced treatment-related adverse events (TRAEs; 22% were grade ≥3). No maximum tolerated dose was defined; the recommended phase 2 dose (RP2D) was 600 mg once every 2 weeks. There were tumor decreases in 34% (59/172) of response-evaluable patients in the dose-escalation cohorts, with objective responses in multiple solid tumor types, including PD-1-refractory disease, and in LAG-3+ non-Hodgkin lymphomas, including CAR-T refractory disease. To enhance potential anti-tumor responses, we tested margetuximab plus tebotelimab. In patients with HER2+ tumors treated with tebotelimab plus margetuximab, 74% (62/84) had TRAEs (17% were grade ≥3). The RP2D was 600 mg once every 3 weeks. The confirmed objective response rate in these patients was 19% (14/72), including responses in patients typically not responsive to anti-HER2/anti-PD-1 combination therapy. ClinicalTrials.gov identifier: NCT03219268 .

Trastuzumab Combined With Ramucirumab and Paclitaxel in Patients With Previously Treated Human Epidermal Growth Factor Receptor 2-Positive Advanced Gastric or Gastroesophageal Junction Cancer

PURPOSE

Trastuzumab-containing chemotherapy is the recommended first-line regimen for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric or gastroesophageal junction (G/GEJ) cancer. We evaluated the safety and efficacy of trastuzumab combined with ramucirumab and paclitaxel as second-line treatment for HER2-positive G/GEJ cancer.

PATIENTS AND METHODS

Patients with HER2-positive advanced G/GEJ cancer who progressed after first-line treatment with trastuzumab-containing chemotherapy were enrolled from five centers in the Republic of Korea. Patients were administered a 28-day cycle of trastuzumab (once on days 1, 8, 15, and 22: 2 mg/kg followed by 4 mg/kg loading dose), ramucirumab (once on days 1 and 15: 8 mg/kg), and paclitaxel (once on days 1, 8, and 15: dose level 1, 80 mg/m2; or dose level -1, 70 mg/m2). Phase II was conducted with the recommended phase II dose (RP2D). Primary end points were determination of RP2D during phase Ib and investigator-assessed progression-free survival (PFS) in patients treated with RP2D.

RESULTS

Dose-limiting toxicity at dose level 1 was not documented during phase Ib, and a full dose combination was selected as the RP2D. Among 50 patients with a median follow-up duration of 27.5 months (95% CI, 17.4 to 37.6), median PFS and overall survival were 7.1 months (95% CI, 4.8 to 9.4) and 13.6 months (95% CI, 9.4 to 17.7), respectively. Objective response rate was 54% (27 of 50, including one complete response), and disease control rate was 96% (48 of 50). Loss of HER2 expression was observed in 34.8% (8 of 23) patients after first-line treatment, and no definite association between HER2 expression and the outcome was revealed. Safety profiles were consistent with previous reports.

CONCLUSION

Trastuzumab combined with ramucirumab and paclitaxel showed appreciable efficacy with manageable safety profiles in patients with previously treated HER2-positive G/GEJ cancer.

A review of treatment options in HER2-low breast cancer and proposed treatment sequencing algorithm

The expansion of the spectrum of human epidermal growth factor receptor 2 (HER2)-status to HER2-low, defined as HER2 expression of 1+ by immunohistochemistry (IHC) or 2+ by IHC without gene amplification, has made a major impact in the field of oncology. The HER2-low expression has emerged as a targetable biomarker, and anti-HER2 antibody-drug conjugate trastuzumab deruxtecan has shown significant survival benefit in pretreated metastatic HER2-low breast cancer (BC). With these recent data, the treatment algorithm for hormone receptor-positive and triple-negative BC needs to be reconsidered, as approximately half of these BCs are HER2-low. Although there are different therapeutic agents for hormone receptor-positive and hormone receptor-negative HER2-low BCs, there is no consensus regarding the sequencing of these agents. In this article, the treatment options for HER2-low BC are enumerated and a treatment sequencing algorithm based on the current clinical evidence proposed.

Peptides Targeting HER2-Positive Breast Cancer Cells and Applications in Tumor Imaging and Delivery of Chemotherapeutics

Breast cancer represents the most common cancer type and one of the major leading causes of death in the female worldwide population. Overexpression of HER2, a transmembrane glycoprotein related to the epidermal growth factor receptor, results in a biologically and clinically aggressive breast cancer subtype. It is also the primary driver for tumor detection and progression and, in addition to being an important prognostic factor in women diagnosed with breast cancer, HER2 is a widely known therapeutic target for drug development. The aim of this review is to provide an updated overview of the main approaches for the diagnosis and treatment of HER2-positive breast cancer proposed in the literature over the past decade. We focused on the different targeting strategies involving antibodies and peptides that have been explored with their relative outcomes and current limitations that need to be improved. The review also encompasses a discussion on targeted peptides acting as probes for molecular imaging. By using different types of HER2-targeting strategies, nanotechnology promises to overcome some of the current clinical challenges by developing novel HER2-guided nanosystems suitable as powerful tools in breast cancer imaging, targeting, and therapy.

Appraisal of Systemic Treatment Strategies in Early HER2-Positive Breast Cancer-A Literature Review

BACKGROUND

The overexpression of the human epidermal growth factor receptor 2 (HER2+) accounts for 15-20% of all breast cancer phenotypes. Even after the completion of the standard combination of chemotherapy and trastuzumab, relapse events occur in approximately 15% of cases. The neoadjuvant approach has multiple benefits that include the potential to downgrade staging and convert previously unresectable tumors to operable tumors. In addition, achieving a pathologic complete response (pCR) following preoperative systemic treatment is prognostic of enhanced survival outcomes. Thus, optimal evaluation among the suitable strategies is crucial in deciding which patients should be selected for the neoadjuvant approach.

METHODS

A literature search was conducted in the Embase, Medline, and Cochrane electronic libraries.

CONCLUSION

The evaluation of tumor and LN staging and, hence, stratifying BC recurrence risk are decisive factors in guiding clinicians to optimize treatment decisions between the neoadjuvant versus adjuvant approaches. For each individual case, it is important to consider the most likely postsurgical outcome, since, if the patient does not obtain pCR following neoadjuvant treatment, they are eligible for adjuvant T-DM1 in the case of residual disease. This review of HER2-positive female BC outlines suitable neoadjuvant and adjuvant systemic treatment strategies for guiding clinical decision making around the selection of an appropriate therapy.

Understanding NK cell biology for harnessing NK cell therapies: targeting cancer and beyond

Gene-engineered immune cell therapies have partially transformed cancer treatment, as exemplified by the use of chimeric antigen receptor (CAR)-T cells in certain hematologic malignancies. However, there are several limitations that need to be addressed to target more cancer types. Natural killer (NK) cells are a type of innate immune cells that represent a unique biology in cancer immune surveillance. In particular, NK cells obtained from heathy donors can serve as a source for genetically engineered immune cell therapies. Therefore, NK-based therapies, including NK cells, CAR-NK cells, and antibodies that induce antibody-dependent cellular cytotoxicity of NK cells, have emerged. With recent advances in genetic engineering and cell biology techniques, NK cell-based therapies have become promising approaches for a wide range of cancers, viral infections, and senescence. This review provides a brief overview of NK cell characteristics and summarizes diseases that could benefit from NK-based therapies. In addition, we discuss recent preclinical and clinical investigations on the use of adoptive NK cell transfer and agents that can modulate NK cell activity.

Smart chitosan-PLGA nanocarriers functionalized with surface folic acid ligands against lung cancer cells

Lung cancer is the second most prevalent and first killer cancer worldwide, and conventional approaches do not have enough ability to suppress it. Therefore, a novel targeted chitosan (CS)-poly lactic-co-glycolic acid (PLGA)-folic acid (FA) nanocarrier was developed for delivery of sorafenib (Sor) to lung cancer cells. The nanocarrier (CPSF) had a size of 30-40 nm with globular shapes. Surface charge and drug content of CPSF were ascertained at about 1.1 mV and 15 %, respectively. Controlled (4 % within 2 h) and pH-sensitive (18 % within 2 h at pH = 5.0) Sor release were observed for the nanocarrier. The MTT assay demonstrated a cell viability of 13 % after 24 h treatment with 400 nM CPSF in A549 cancer cells while it was 78 % in MSC normal cells. The qRT-PCR revealed >8 folds and 11 folds increase for Caspase9 and P53 genes after 5 h treatment with 100 nM (IC₅₀) CPSF; but a reduction of 5 folds was observed for the Bcl2 gene. Besides, 57 % and 20 % apoptosis were attained in cell cycle arrest and apoptosis assays for CPSF, respectively. CPF indicated about 88 % internalization in cancer cells. These data prove that CPSF is a promising nanodelivery system for lung cancer suppression.

Gastric cancer treatment: recent progress and future perspectives

Gastric cancer (GC) is one of the most common malignancies worldwide. Most patients are diagnosed at advanced stages due to the subtle symptoms of earlier disease and the low rate of regular screening. Systemic therapies for GC, including chemotherapy, targeted therapy and immunotherapy, have evolved significantly in the past few years. For resectable GC, perioperative chemotherapy has become the standard treatment. Ongoing investigations are exploring the potential benefits of targeted therapy or immunotherapy in the perioperative or adjuvant setting. For metastatic disease, there have been notable advancements in immunotherapy and biomarker-directed therapies recently. Classification based on molecular biomarkers, such as programmed cell death ligand 1 (PD-L1), microsatellite instability (MSI), and human epidermal growth factor receptor 2 (HER2), provides an opportunity to differentiate patients who may benefit from immunotherapy or targeted therapy. Molecular diagnostic techniques have facilitated the characterization of GC genetic profiles and the identification of new potential molecular targets. This review systematically summarizes the main research progress in systemic treatment for GC, discusses current individualized strategies and presents future perspectives.

Defining the Emergence of New Immunotherapy Approaches in Breast Cancer: Role of Myeloid-Derived Suppressor Cells

Breast cancer (BC) continues to be the most diagnosed tumor in women and a very heterogeneous disease both inter- and intratumoral, mainly given by the variety of molecular profiles with different biological and clinical characteristics. Despite the advancements in early detection and therapeutic strategies, the survival rate is low in patients who develop metastatic disease. Therefore, it is mandatory to explore new approaches to achieve better responses. In this regard, immunotherapy arose as a promising alternative to conventional treatments due to its ability to modulate the immune system, which may play a dual role in this disease since the relationship between the immune system and BC cells depends on several factors: the tumor histology and size, as well as the involvement of lymph nodes, immune cells, and molecules that are part of the tumor microenvironment. Particularly, myeloid-derived suppressor cell (MDSC) expansion is one of the major immunosuppressive mechanisms used by breast tumors since it has been associated with worse clinical stage, metastatic burden, and poor efficacy of immunotherapies. This review focuses on the new immunotherapies in BC in the last five years. Additionally, the role of MDSC as a therapeutic target in breast cancer will be described.

Deviating HER2 test results in gastric cancer: analysis from the prospective multicenter VARIANZ study

PURPOSE

The prospective multicenter VARIANZ study aimed to identify resistance biomarkers for HER2-targeted treatment in advanced gastric and esophago-gastric junction cancer (GC, EGJC). HER2 test deviations were found in 90 (22.3%) of 404 cases (central versus local testing) and were associated with negative impact on survival for trastuzumab-treated patients. Here, we investigated methodological and biological variables that may promote deviating HER2 test results.

METHODS

We analyzed HER2 testing procedures and participation in quality assurance programs of 105 participating local pathology laboratories. Furthermore, tumor localization and histological subtypes were compared between patients with centrally confirmed (central HER2 + /local HER2 + , n = 68) and unconfirmed HER2 status (central HER2 -/local HER2 + , n = 68).

RESULTS

For central HER2 testing, concordance between in situ hybridization (ISH) and immunohistochemistry (IHC) was 98.3%, with IHC sensitivity of 93.3% (84 IHC + of 90 ISH +), specificity of 99.5% (389 IHC- of 391 ISH-), and a positive diagnosis rate of 97.7%. Central confirmation of the local HER2 IHC scores were seen for the majority of locally HER2- IHC 0/1 (172/178; 96.6%), but less frequently for locally IHC3 + (57/124; 46.0%) cases. Deviation rate was not associated with IHC antibody platform used in the local pathology institute neither with participation in quality-assuring tests. Regarding tumor characteristics, deviating test results were more frequently found in GC vs. EGJC (69.1% vs. 39.7%; p = 0.001) and in Laurén diffuse vs. intestinal subtype (23.5% vs. 5.9%, p = 0.004).

CONCLUSION

Tumor localization and histological subtype have an impact on HER2 test deviation rates. Assessment of HER2 remains challenging for GC and EGJC.

Current developments in gastric cancer: from molecular profiling to treatment strategy

Gastric cancer and gastro-oesophageal junction cancer represent a global health-care challenge. Despite the efficacy of improved chemotherapy and surgical options, these patients still have a poor prognosis. In advanced disease, only trastuzumab and some immune checkpoint inhibitors, such as nivolumab and pembrolizumab in addition to chemotherapy, have demonstrated consistent and reliable efficacy in patients with HER2-positive and PDL1-positive tumours, respectively. In this Review, we discuss the intrinsic characteristics of gastric and gastro-oesophageal cancer from the molecular and clinical perspectives and provide a comprehensive review of previously reported and ongoing phase II and III clinical trials with targeted agents and immunotherapy in advanced and localized settings. Finally, we suggest alternative strategies to help overcome current challenges in precision medicine and to improve outcomes for these patients.

Advances in targeted therapy for gastric cancer based on tumor driver genes

As the understanding of the pathogenic mechanisms of gastric cancer deepens and the identification of gastric cancer driver genes advances, drugs targeting gastric cancer driver genes have been applied in clinical practice. Among them, trastuzumab, as the first targeted drug for gastric cancer, effectively inhibits the proliferation and metastasis of tumor cells by targeting overexpressed human epidermal growth factor receptor 2 (HER2). Trastuzumab has become the standard treatment for HER2-positive gastric cancer patients. Ramucirumab, on the other hand, inhibits tumor angiogenesis by targeting vascular endothelial growth factor receptor 2 (VEGFR2) and has been used as second-line therapy for advanced gastric cancer patients. In addition, bemarituzumab targets overexpressed fibroblast growth factor receptor 2 (FGFR2), while zolbetuximab targets overexpressed claudin 18.2 (CLDN18.2), significantly extending progression-free survival and overall survival in patients with gastric cancer in clinical trials. This article reviews the roles of tumor driver genes in the progression of gastric cancer, and the treatment strategies for gastric cancer primarily based on targeting HER2, VEGF, FGFR2, CLDN18.2 and MET. This provides a reference for clinical application of targeted therapy for gastric cancer.

Challenges and future of HER2-positive gastric cancer therapy

Gastric cancer is the fifth most common cancer worldwide, and the treatment of advanced gastric cancer has relatively little progress. With the continuous development of molecularly targeted therapy for tumors, it has been discovered that human epidermal growth factor receptor 2 (HER2) contributes to the poor prognosis and pathogenesis of various cancers. In order to treat HER2-positive advanced gastric cancer, Trastuzumab has emerged as the first first-line targeted medication used in conjunction with chemotherapy. The consequent trastuzumab resistance has become an important issue, and various new HER2-targeted gastric cancer drugs are emerging to address this challenge. This review's primary concern is the drug mechanism of various HER2-positive gastric cancer targeted therapy and fresh techniques of detection.

Biology and Treatment of HER2-Low Breast Cancer

Current guidelines recommend a dichotomous classification of HER2 as either positive or negative, to guide clinicians in treatment decisions. Until now, only patients with HER2-positive breast cancer (BC) had been demonstrated to derive clinical benefit from anti-HER2 therapies. However, novel ADCs have recently emerged, with activity in the large population of patients with HER2-low-expressing BC. Although it remains unclear whether HER2-low BC represents a distinct entity, given the therapeutic implication its crucial to accurately distinguish HER2-low from HER2-0 BC. Efforts are needed to standardize HER2 testing in BC and to introduce more sensitive assays to better discriminate HER2 levels.

Margetuximab Versus Trastuzumab in Patients With Previously Treated HER2-Positive Advanced Breast Cancer (SOPHIA): Final Overall Survival Results From a Randomized Phase 3 Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Final overall survival (OS) in SOPHIA (ClinicalTrials.gov identifier: NCT02492711), a study of margetuximab versus trastuzumab, both with chemotherapy, in patients with previously treated human epidermal growth factor receptor 2-positive advanced breast cancer, is reported with updated safety. Overall, 536 patients in the intention-to-treat population were randomly assigned to margetuximab (15 mg/kg intravenously once every 3 weeks; n = 266) plus chemotherapy or trastuzumab (6 mg/kg intravenously once every 3 weeks after a loading dose of 8 mg/kg; n = 270) plus chemotherapy. Primary end points were progression-free survival, previously reported, and OS. Final OS analysis was triggered by 385 prespecified events. The median OS was 21.6 months (95% CI, 18.89 to 25.07) with margetuximab versus 21.9 months (95% CI, 18.69 to 24.18) with trastuzumab (hazard ratio [HR], 0.95; 95% CI, 0.77 to 1.17; P = .620). Preplanned, exploratory analysis of CD16A genotyping suggested a possible improvement in OS for margetuximab in CD16A-158FF patients versus trastuzumab (median OS, 23.6 v 19.2 months; HR, 0.72; 95% CI, 0.52 to 1.00) and a possible improvement in OS for trastuzumab in CD16A-158VV patients versus margetuximab (median OS, 31.1 v 22.0 months; HR, 1.77; 95% CI, 1.01 to 3.12). Margetuximab safety was comparable with trastuzumab. Final overall OS analysis did not demonstrate margetuximab advantage over trastuzumab. Margetuximab studies in patients with human epidermal growth factor receptor 2-positive breast cancer with different CD16A allelic variants are warranted.

Breakthroughs in the Systemic Treatment of HER2-Positive Advanced/Metastatic Gastric Cancer: From Singlet Chemotherapy to Triple Combination

Gastric cancer is heterogeneous in morphology, biology, genomics, and treatment response. Alterations in human epidermal growth factor receptor 2 (HER2) overexpression, microsatellite instability (MSI) status, programmed death-ligand 1 (PD-L1) levels, and fibroblast growth factor receptor 2 (FGFR2) can be used as biomarkers. Since the combination of fluoropyrimidine/platinum plus trastuzumab that was investigated in the ToGA trial was approved as a standard of care in HER2-positive patients in 2010, no other agents showed efficacy in the first- (HELOISE, LOGiC, JACOB trials) and second- (TyTAN, GATSBY, T-ACT trials) line treatments. Despite the success in treating breast cancer, various anti-HER2 agents, including a monoclonal antibody (pertuzumab), an antibody-drug conjugate (ADC; trastuzumab emtansine [T-DM1]), and a small molecule (lapatinib) failed to translate into clinical benefits until the KEYNOTE-811 (first-line) and DESTINY-Gastri01 (≥second-line) trials were conducted. The incorporation of HER2-directed treatment with immune checkpoint inhibitors in the form of a monoclonal antibody or ADC is now approved as a standard treatment. Despite the promising results of new agents (engineered monoclonal antibodies, bi-specific antibodies, fusion proteins, and small molecules) in the early phase of development, the management of HER2-positive gastric cancer requires further optimization to achieve precision medicine with a chemotherapeutic backbone. Treatment resistance is a complex process that can be overcome using a combination of chemotherapy, targeted agents, and immune checkpoint inhibitors, including novel agents. HER2 status must be reassessed in patients undergoing anti-HER2 treatment with disease progression after the first-line treatment. As a general guideline, patients who need systemic treatment should receive chemotherapy plus targeted agents, anti-angiogenic agents, immune checkpoint inhibitors, or their combinations.

Innovative Therapeutic Approaches for Patients with HER2-Positive Breast Cancer

Overexpression of human epidermal growth factor receptor 2 (HER2), a transmembrane tyrosine kinase receptor, has been described in about 15-20% of breast cancer (BC) and is associated with poor outcomes. Trastuzumab is the first anti-HER2 monoclonal antibody (mAB) that blocks receptor activity but it also activates immune response against cancer cells, thus, revolutionizing the prognosis of patients with HER2-positive BC. Over the years, new therapies have been developed, including other mAbs and tyrosine kinase inhibitors (TKIs) that required multimodal approaches with chemotherapy to optimize their anticancer activity. This chapter gives a comprehensive overview of the last advancements including new approaches and future combinations, which seem to be very promising in overcoming resistance to the traditional anti-HER2 treatments. A modern therapeutic algorithm should include treatment options based on tumour patterns and a patient-centred approach. A proper patient's selection is crucial to derive maximal benefits from a treatment strategy and emerging biomarkers should be integrated along with the HER2 status, which is currently the only validated biomarker in the context of HER2-positive disease. These biomarkers might include molecular features with reported prognostic/predictive significance, such as phosphatidylinositol 3' -kinase (PI3K) or mitogen-activated protein kinase (MAPK) pathways, programmed cell death protein ligand 1 (PD-L1), and tumour-infiltrating lymphocytes (TILs), which all affect prognosis and response to treatments.

The diverse landscape of dermatologic toxicities of non-immune checkpoint inhibitor monoclonal antibody-based cancer therapy

BACKGROUND

Since their first approval 25 years ago, monoclonal antibodies (mAbs) have become important targeted cancer therapeutics. However, dermatologic toxicities associated with non-immune checkpoint inhibitor (non-ICI) mAbs may complicate the course of cancer treatment. Data on the incidence and types of these reactions are limited.

METHODS

A comprehensive review was conducted on dermatologic toxicities associated with different classes of non-ICI mAbs approved for treatment of solid tumors and hematologic malignancies. The review included prospective Phase 1, 2, and 3 clinical trials; retrospective literature reviews; systematic reviews/meta-analyses; and case series/reports.

RESULTS

Dermatologic toxicities were associated with several types of non-ICI mAbs. Inflammatory reactions were the most common dermatologic toxicities, manifesting as maculopapular, urticarial, papulopustular/acneiform, and lichenoid/interface cutaneous adverse events (cAEs) with non-ICI mAbs. Immunobullous reactions were rare and a subset of non-ICI mAbs were associated with the development of vitiligo cAEs.

CONCLUSION

Dermatologic toxicities of non-ICI mAbs are diverse and mostly limited to inflammatory reactions. Awareness of the spectrum of the histopathologic patterns of cAE from non-ICI mAbs therapy is critical in the era of oncodermatology and oncodermatopathology.

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

Approximately 20% of breast cancers (BC) overexpress human epidermal growth factor receptor 2 (HER2). This subtype of BC is a clinically and biologically heterogeneous disease that was associated with an increased risk for the development of systemic and brain metastases and poor overall survival before anti-HER2 therapies were developed. The standard of care was dual blockade with trastuzumab and pertuzumab as first-line followed by TDM-1 as second-line. However, with the advent of new HER2-targeted monoclonal antibodies, tyrosine kinase inhibitors and antibody- drug conjugates, the clinical outcomes of patients with HER2-positive BC have changed dramatically in recent years, leading to a paradigm shift in the treatment of the disease. Notably, the development of new-generation ADCs has led to unprecedented results compared with T-DM1, currently establishing trastuzumab deruxtecan as a new standard of care in second-line. Despite the widespread availability of HER2-targeted therapies, patients with HER2-positive BC continue to face the challenges of disease progression, treatment resistance, and brain metastases. Response rate and overall life expectancy decrease with each additional line of treatment, and tumor heterogeneity remains an issue. In this review, we update the new-targeted therapeutic options for HER2-positive BC and highlight the future perspectives of treatment in this setting.

A Review of Margetuximab-Based Therapies in Patients with HER2-Positive Metastatic Breast Cancer

Breast cancer (BC) is the most commonly diagnosed cancer globally, with high mortality rates. Targeted drug therapies have revolutionized cancer treatment. For example, treatment with human epidermal receptor 2 (HER2) antagonists has markedly improved the prognosis of patients with HER2-positive BC (HER2 + BC). However, HER2+ metastatic BC (MBC) remains prevalent owing to its resistance to conventional anti-HER2 drugs. Therefore, novel agents are needed to overcome the limitations of existing cancer treatments and to enhance the progression-free and overall survival rates. Progress has been made by optimizing the fragment crystallizable (Fc) domain of trastuzumab, an IgG1 monoclonal, chimeric anti-HER2 antibody, to develop margetuximab. The modified Fc domain of margetuximab enhances its binding affinity to CD16A and decreases its binding affinity to CD32B, thereby promoting its antitumor activity. This review summarizes studies on the efficacy of margetuximab, discusses its utility as an anti-HER2 monoclonal antibody drug for the treatment of HER2 + BC, and presents the latest advances in the treatment of BC. This review provides insights into the clinical implication of margetuximab in HER2 + MBC treatment.

Focusing on NK cells and ADCC: A promising immunotherapy approach in targeted therapy for HER2-positive breast cancer

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer has a high metastatic potential. Monoclonal antibodies (mAbs) that target HER2, such as trastuzumab and pertuzumab, are the cornerstone of adjuvant therapy for HER2-positive breast cancer. A growing body of preclinical and clinical evidence points to the importance of innate immunity mediated by antibody-dependent cellular cytotoxicity (ADCC) in the clinical effect of mAbs on the resulting anti-tumor response. In this review, we provide an overview of the role of natural killer (NK) cells and ADCC in targeted therapy of HER2-positive breast cancer, including the biological functions of NK cells and the role of NK cells and ADCC in anti-HER2 targeted drugs. We then discuss regulatory mechanisms and recent strategies to leverage our knowledge of NK cells and ADCC as an immunotherapy approach for HER2-positive breast cancer.

Immune-based combination therapy for esophageal cancer

Esophageal cancer (EC) is an aggressive malignancy raising a healthcare concern worldwide. Standard treatment options include surgical resection, chemotherapy, radiation therapy, and targeted molecular therapy. The five-year survival rate for all stages of EC is approximately 20%, ranging from 5% to 47%, with a high recurrence rate and poor prognosis after treatment. Immunotherapy has shown better efficacy and tolerance than conventional therapies for several malignancies. Immunotherapy of EC, including immune checkpoint inhibitors, cancer vaccines, and adoptive cell therapy, has shown clinical advantages. In particular, monoclonal antibodies against PD-1 have a satisfactory role in combination therapy and are recommended for first- or second-line treatments. Here, we present a systematic summary and analysis of immunotherapy-based combination therapies for EC.

Complete response in patient with liver metastasis of HER2-positive breast cancer following therapy with margetuximab: a case report

Metastatic human epidermal growth factor receptor 2 (HER2) positive breast cancer has a poor prognosis and few effective targeted therapies. However, several anti-HER2 agents are emerging in conjunction with chemotherapy, which may lead to increased rates of pathological complete response in patients with HER2-positive metastatic breast cancer. Among them, margetuximab demonstrated a significant improvement in progression-free survival compared with trastuzumab, when combined with chemotherapy in pretreated patients. Here we present a case of a 67-year-old female patient who was diagnosed with HER2-positive, histological grade III and invasive ductal carcinoma of the left breast in September 2018. She received postoperative adjuvant therapy with EC-TH plus radiotherapy, followed by therapy with HER2-targeted trastuzumab for 1 year (till December 2019). In May 2020, routine reexamination showed a supraclavicular lymph node and bone metastasis. Patient was then treated with pyrotinib, capecitabine and bisphosphonate for a period of 3 months. In December 2020, liver MRI revealed multiple liver metastases. The patient received eight cycles of second-line therapy (vinorelbine plus margetuximab) from January 2021. Since the ninth cycle, the patient was continued with only margetuximab. In March 2021, MRI showed a 70% decrease in the liver metastasis lesions. By June 2021, liver lesions were totally disappeared. During therapy, patient experienced only grade-1 anemia. This case demonstrates that margetuximab plus chemotherapy is safe and might bring clinical benefits for patients with HER2-positive breast cancer with liver metastasis. Further studies evaluating the efficacy and safety of margetuximab in Chinese HER2-positive breast cancer patients are needed.

Combined Vaccination with B Cell Peptides Targeting Her-2/neu and Immune Checkpoints as Emerging Treatment Option in Cancer

The application of monoclonal antibodies (mAbs), targeting tumor-associated (TAAs) or tumor-specific antigens or immune checkpoints (ICs), has shown tremendous success in cancer therapy. However, the application of mAbs suffers from a series of limitations, including the necessity of frequent administration, the limited duration of clinical response and the emergence of frequently pronounced immune-related adverse events. However, the introduction of mAbs has also resulted in a multitude of novel developments for the treatment of cancers, including vaccinations against various tumor cell-associated epitopes. Here, we reviewed recent clinical trials involving combination therapies with mAbs targeting the PD-1/PD-L1 axis and Her-2/neu, which was chosen as a paradigm for a clinically highly relevant TAA. Our recent findings from murine immunizations against the PD-1 pathway and Her-2/neu with peptides representing the mimotopes/B cell peptides of therapeutic antibodies targeting these molecules are an important focus of the present review. Moreover, concerns regarding the safety of vaccination approaches targeting PD-1, in the context of the continuing immune response, as a result of induced immunological memory, are also addressed. Hence, we describe a new frontier of cancer treatment by active immunization using combined mimotopes/B cell peptides aimed at various targets relevant to cancer biology.

Strategies for the treatment of HER2+ advanced breast cancer based on clinical practice in Chinese patients: a roundtable discussion

Human epithelial growth factor receptor 2-positive (HER2+) breast cancer is easy to relapse and metastasize in the early stage, and usually has more aggressive clinical behavior and worse patient survival outcomes as compared with estrogen receptor-positive (ER+), HER2-negative (HER2-) breast cancer. The HER2+ breast cancer has been significantly enhanced by trastuzumab and other multiple novel HER2 anti-tumor drugs. The dual combination regimen of trastuzumab + pertuzumab has been established as the standard first-line therapy for advanced HER2+ patients, and pyrotinib with capecitabine is the preferred second-line treatment in Chinese patients. However, no third- or later-line regimens are currently recommended, and thus, the treatment needs of these patients remain unmet. Margetuximab is a human/mouse chimeric anti-HER2 immunoglobulin G1 (IgG1) monoclonal antibody (mAb) based on the murine precursor of trastuzumab, has shown greater efficacy than trastuzumab in terms of its natural killer (NK) cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) effect and may become the preferred solution for HER2+ metastatic breast cancer (mBC) following progression on second-line therapy with small molecule tyrosine kinase inhibitors (TKIs). This paper explores discussion of therapeutic strategies of anti-HER2 drugs based on Chinese clinical practice, and summarizes the consensus and controversy in the post-anti-HER2 TKIs guideline recommendations, so as to provide certain guidance to HER2+ mBC patients pretreated with TKIs in the third or later lines.

Therapeutic landscape of advanced HER2-positive breast cancer in 2022

HER2-positive breast cancer is an aggressive subtype of breast cancer with five-year survival rates of 30% for the advanced stage. The development of anti-HER2 treatments has led to a paradigm shift in the management and clinical outcomes of advanced HER2-positive breast cancer patients. The standard first-line treatment consists of taxane-based chemotherapy plus dual anti-HER2 therapies with trastuzumab and pertuzumab. The antibody-drug conjugate (ADC) ado-trastuzumab emtansine (T-DM1) has been a second-line therapeutic standard, but the second-line treatment approach is rapidly evolving. Given a substantial advantage of another ADC, Fam-trastuzumab deruxtecan (T-DXd), compared to T-DM1 in a recent randomized trial in the second-line setting, T-DXd is currently the preferred second-line option. Optimal third-line treatment strategies are still not established, and multiple approaches have been used including combinations based on capecitabine, trastuzumab, or both with oral anti-HER2 tyrosine kinase inhibitors. Tucatinib plus capecitabine and trastuzumab, lapatinib plus trastuzumab, neratinib or lapatinib plus capecitabine are some of the FDA approved combinations. Another newer agent approved for third- or later-line therapy in the metastatic setting is margetuximab, an Fc-engineered anti-HER2 monoclonal antibody, in combination with chemotherapy. Other novel agents currently under clinical trials are the drugs that indirectly target HER2, including immune cell cycle inhibitors, PI3K/mTOR inhibitors, and immunotherapy agents.

Small-molecule inhibitors, immune checkpoint inhibitors, and more: FDA-approved novel therapeutic drugs for solid tumors from 1991 to 2021

The United States Food and Drug Administration (US FDA) has always been a forerunner in drug evaluation and supervision. Over the past 31 years, 1050 drugs (excluding vaccines, cell-based therapies, and gene therapy products) have been approved as new molecular entities (NMEs) or biologics license applications (BLAs). A total of 228 of these 1050 drugs were identified as cancer therapeutics or cancer-related drugs, and 120 of them were classified as therapeutic drugs for solid tumors according to their initial indications. These drugs have evolved from small molecules with broad-spectrum antitumor properties in the early stage to monoclonal antibodies (mAbs) and antibody‒drug conjugates (ADCs) with a more precise targeting effect during the most recent decade. These drugs have extended indications for other malignancies, constituting a cancer treatment system for monotherapy or combined therapy. However, the available targets are still mainly limited to receptor tyrosine kinases (RTKs), restricting the development of antitumor drugs. In this review, these 120 drugs are summarized and classified according to the initial indications, characteristics, or functions. Additionally, RTK-targeted therapies and immune checkpoint-based immunotherapies are also discussed. Our analysis of existing challenges and potential opportunities in drug development may advance solid tumor treatment in the future.

Targeting HER2 in metastatic gastroesophageal adenocarcinomas: What is new?

Gastric and esophageal adenocarcinomas represent a biologically heterogeneous disease. The identification, in early eighties, of human epidermal growth factor receptor 2 (HER2) overexpression, being present in 12 to 20% of the cases, marked a major milestone in the efforts of unraveling the molecular complexity of this disease. This led to the development of anti-HER2-therapies, trastuzumab being the first to demonstrate, in combination with cisplatin and 5FU/capecitabine chemotherapy, an improvement in response rate and survival in the first-line setting of patients with metastatic, HER2-positive gastroesophageal adenocarcinomas. Afterwards, during a decade, several studies have tried new strategies either to block HER2 pathway differently or to combine different anti-HER2, without efficacy. Everything changed with studies demonstrating additive effect between anti-HER2 and immune checkpoint inhibitors and leading to phase III clinical trials combining anti-HER2 and anti-PD-L1/PD1 therapies. Pembrolizumab, a PD-1 inhibitor, was recently granted by FDA an accelerated approval, in patients with HER2-positive gastro-oesophageal adenocarcinomas, in combination with trastuzumab and platinum-based chemotherapy following meaningful improvement in overall response rate over standard treatment. Progression-free and overall-survival results are still awaited to change our first-line standard treatment. Furthermore, new HER2 inhibitors have been developed, blocking HER2-mediated pathway signaling via different mechanisms from pan-HER inhibition to anti-HER2 antibody drug conjugates with promising results in pretreated patients. Trastuzumab-deruxtecan has in particular showed interesting results in pretreated patients. We present here a review of the recent data and perspectives in HER2-positive metastatic gastroesophageal adenocarcinomas.

HER2-targeted advanced metastatic gastric/gastroesophageal junction adenocarcinoma: treatment landscape and future perspectives

Recently, the global incidence of gastric/gastroesophageal junction (G/GEJ) cancer has remained high. China is also a large country with a high gastric cancer (GC) incidence rate, where the cases of GC account for 40% of all cases worldwide. More than 90% of GEJ cancers are the adenocarcinoma pathological type. Patients with early-stage G/GEJ adenocarcinoma may have a better prognosis after surgery. In contrast, patients with advanced metastatic G/GEJ adenocarcinoma usually choose comprehensive treatment based on systemic pharmacotherapy, but the subsequent long-term survival is not optimistic. The discovery of various biomarkers, especially microsatellite instability (MSI), programmed cell death-ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), tumor mutational burden (TMB) and Epstein-Barr virus (EBV), has led to the identification of an increasing number of targeted populations and has greatly improved the clinical efficacy of treatments for G/GEJ adenocarcinoma. The ToGA trial added trastuzumab to standard chemotherapy, showed improved survival of patients with HER2-positive advanced G/GEJ adenocarcinoma and brought these patients into a new era of HER2-targeted therapy. Moreover, many HER2-targeted agents have been developed and studied in patients with advanced HER2-positive G/GEJ adenocarcinoma who have demonstrated excellent clinical outcomes. However, many patients experience disease progression with HER2-targeted therapy; hence, new anti-HER2 drugs keep being developed, significantly reducing HER2 resistance. This paper reviews HER2-targeted drugs for advanced metastatic G/GEJ adenocarcinoma, potential resistance mechanisms and future directions.

HER2 Inhibition in Gastric Cancer-Novel Therapeutic Approaches for an Established Target

Gastric cancer is a leading cause of cancer-related deaths globally. Human epidermal growth receptor 2 (HER2) overexpression of HER2 gene amplification is present in 20% of gastric cancers and defines a subset amenable to HER2-directed therapeutics. The seminal ToGA study led to routine use of the monoclonal antibody trastuzumab in conjunction to platinum-fluoropyridimine first-line chemotherapy for HER2-positive gastric cancers as standard-of-care. Although limited progress was made in the decade following ToGA, there is now an abundance of novel therapeutic approaches undergoing investigation in parallel. Additionally, new data from randomised trials have indicated efficacy of the antibody-drug conjugate trastuzumab deruxtecan in chemorefractory patients and increased responses with the addition of first-line immune checkpoint blockade to trastuzumab and chemotherapy. This review will outline the data supporting HER2 targeting in gastric cancers, discuss mechanisms of response and resistance to HER2-directed therapies and summarise the emerging therapies under clinical evaluation that may evolve the way we manage this subset of gastric cancers in the future.

Harnessing natural killer cells for cancer immunotherapy: dispatching the first responders

Natural killer (NK) cells have crucial roles in the innate immunosurveillance of cancer and viral infections. They are 'first responders' that can spontaneously recognize abnormal cells in the body, rapidly eliminate them through focused cytotoxicity mechanisms and potently produce pro-inflammatory cytokines and chemokines that recruit and activate other immune cells to initiate an adaptive response. From the initial discovery of the diverse cell surface receptors on NK cells to the characterization of regulatory events that control their function, our understanding of the basic biology of NK cells has improved dramatically in the past three decades. This advanced knowledge has revealed increased mechanistic complexity, which has opened the doors to the development of a plethora of exciting new therapeutics that can effectively manipulate and target NK cell functional responses, particularly in cancer patients. Here, we summarize the basic mechanisms that regulate NK cell biology, review a wide variety of drugs, cytokines and antibodies currently being developed and used to stimulate NK cell responses, and outline evolving NK cell adoptive transfer approaches to treat cancer.

Development of a variant of dinutuximab with enhanced anti‐tumor efficacy and reduced induction of neuropathic pain

Dinutuximab (ch14.18) was the first approved monoclonal antibody against the tumor‐associated antigen disialoganglioside GD2. Despite its success in treating neuroblastoma (NB), it triggers a significant amount of neuropathic pain in patients, possibly through complement‐dependent cytotoxicity (CDC). We hypothesized that modifying ch14.18 using antibody engineering techniques, such as humanization, affinity maturation, and Fc engineering, may enable the development of next‐generation GD2‐specific antibodies with reduced neuropathic pain and enhanced antitumor activity. In this study we developed the H3‐16 IgG1m4 antibody from ch14.18 IgG1. H3‐16 IgG1m4 exhibited enhanced binding activity to GD2 molecules and GD2‐positive cell lines as revealed by ELISA, and its cross‐binding activity to other gangliosides was not altered. The CDC activity of H3‐16 IgG1m4 was decreased, and the antibody‐dependent cellular cytotoxicity (ADCC) activity was enhanced. The pain response after H3‐16 IgG1m4 antibody administration was also reduced, as demonstrated using the von Frey test in Sprague–Dawley (SD) rats. In summary, H3‐16 IgG1m4 may have potential as a monoclonal antibody with reduced side effects.

From CD16a Biology to Antibody-Dependent Cell-Mediated Cytotoxicity Improvement

Antibody-dependent cell-mediated cytotoxicity (ADCC) is a potent cytotoxic mechanism that is mainly mediated in humans by natural killer (NK) cells. ADCC mediates the clinical benefit of several widely used cytolytic monoclonal antibodies (mAbs), and increasing its efficacy would improve cancer immunotherapy. CD16a is a receptor for the Fc portion of IgGs and is responsible to trigger NK cell-mediated ADCC. The knowledge of the mechanism of action of CD16a gave rise to several strategies to improve ADCC, by working on either the mAbs or the NK cell. In this review, we give an overview of CD16a biology and describe the latest strategies employed to improve antibody-dependent NK cell cytotoxicity.

Molecular pathogenesis and emerging targets of gastric adenocarcinoma

Gastric adenocarcinoma (GC) is a devastating disease and is the third leading cause of cancer deaths worldwide. This heterogeneous disease has several different classification systems that consider histological appearance and genomic alterations. Understanding the etiology of GC, including infection, hereditary conditions, and environmental factors, is of particular importance and is discussed in this review. To improve survival in GC, we also must improve our therapeutic strategies. Here, we discuss new targets that warrant further exploration.

Profile of Margetuximab: Evidence to Date in the Targeted Treatment of Metastatic HER2-positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) positive breast cancer accounts for about 20% of all breast cancers and this subtype has been historically associated with worse prognosis. Margetuximab is a chimeric and Fc-engineered monoclonal antibody directed to HER2 that can enhance the activation of the innate and adaptive immune responses while maintaining trastuzumab’s antiproliferative effects. Margetuximab in combination with chemotherapy was approved by the US FDA in December 2020 for patients with metastatic HER2+ breast cancer who have received two or more HER2-targeted regimens. This approval was based on the results of the SOPHIA trial that showed a modest improvement in progression-free survival with margetuximab and chemotherapy compared to trastuzumab and chemotherapy. Ongoing studies are assessing the role of margetuximab in other settings and diseases such as early stage breast cancer and gastrointestinal malignancies. Here we review the rationale for the development of margetuximab, previous and ongoing clinical trials and current role in clinical practice.

Colorectal Cancer Heterogeneity and the Impact on Precision Medicine and Therapy Efficacy

Novel targeted therapies for metastatic colorectal cancer are needed to personalize treatments by guiding specific biomarkers selected on the genetic profile of patients. RAS and BRAF inhibitors have been developed for patients who become unresponsive to standard therapies. Sotorasib and adagrasib showed promising results in phase I/II basket trial and a phase III trial was planned with a combination of these RAS inhibitors and anti-EGFR monoclonal antibodies. Encorafenib and binimetinib were administered in phase II clinical trials for BRAF mutated patients. Pembrolizumab is now recommended in patients exhibiting microsatellite instability. Larotrectinib and entrectinib showed a fast and durable response with few and reversible adverse events in cases with NTRK fusions. Trastuzumab and trastuzumab deruxtecan exhibited promising and durable activity in HER-2-positive patients. In this review, the reasons for an extension of the molecular profile of patients were assessed and placed in the context of the advancements in the understanding of genetics. We highlight the differential effect of new targeted therapies through an ever-deeper characterization of tumor tissue. An overview of ongoing clinical trials is also provided.

Efficacy and safety of inetetamab in combination with chemotherapy as first-line treatment of HER2-positive metastatic breast cancer: a subgroup analysis in the HOPES study

Background

Our aim was to evaluate the efficacy and safety of inetetamab plus chemotherapy in the first-line treatment of HER2-positive metastatic breast cancer.

Methods

A HOPES study was conducted on patients with HER2-positive metastatic breast cancer. Eligible patients were randomly divided into test group and control group at a 2:1 ratio. Among them, patients in test group received inetetamab plus vinorelbine. Concurrently, patients in the control group received vinorelbine. During the trial, safety evaluation was conducted every 4 weeks and efficacy evaluation was conducted every 8 weeks. As assessed by the Response Criteria Evaluation in Solid Tumors (RECIST) 1.0 criteria, the primary endpoint was progression-free survival (PFS) and the secondary endpoints included objective response rate (ORR) and disease control rate (DCR). Safety was estimated according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2.0. Efficacy and safety of the postoperative recurrent-metastases first-line subgroup in the HOPES registry study of inetetamab was analyzed and compared with previous clinical studies of trastuzumab in the first-line treatment of HER2-positive metastatic breast cancer.

Results

In total, we included 315 patients. Among them, 114 patients in the postoperative recurrent-metastases first-line subgroup were assigned to the full analysis set (FAS) (test group, 72; and control group, 42). The test group significantly prolonged median PFS (mPFS) (11.1 vs. 3.3 months of the control group; P<0.0001). ORR and DCR were remarkably higher than the control group (ORR, 61.5% vs. 29.7% with an increase of 31.8%, P=0.0224; DCR, 93.8% vs. 59.4% with an increase of 34.4%, P=0.0003). Efficacy and safety of postoperative recurrent-metastases first-line subgroup in the HOPES study was comparable to previous clinical studies of trastuzumab as first-line treatment of HER2-positive metastatic breast cancer.

Conclusions

Inetetamab has shown efficacy and safety equivalent to trastuzumab for patients in the first-line treatment of postoperative recurrence-metastases HER2-positive breast cancer, which confirms its important status and potential as first-line treatment. Inetetamab provides more first-line targeted therapy options for patients with HER2-positive metastatic breast cancer.

Immunotherapy for HER2-Positive Breast Cancer: Clinical Evidence and Future Perspectives

Breast cancer is the most common malignancy among women worldwide, and HER2-positive breast cancer accounts for approximately 15% of all breast cancer diagnoses. The advent of HER2-targeting therapies has dramatically improved the survival of these patients, significantly reducing their risk of recurrence and death. However, as a significant proportion of patients ultimately develop resistance to these therapies, it is extremely important to identify new treatments to further improve their clinical outcomes. Immunotherapy has revolutionized the treatment and history of several cancer types, and it has already been approved as a standard of care for patients with triple-negative breast cancer. Based on a strong preclinical rationale, immunotherapy in HER2-positive breast cancer represents an intriguing field that is currently under clinical investigation. There is a close interplay between HER2-targeting therapies (both approved and under investigation) and the immune system, and several new immunotherapeutic strategies, including immune checkpoint inhibitors, CAR-T cells and therapeutic vaccines, are being studied in this disease. In this narrative review, we discuss the clinical evidence and the future perspectives of immunotherapy for patients with HER2-positive breast cancer.

Developments in the Management of Metastatic HER2-Positive Breast Cancer: A Review

Approximately 20% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2), providing an actionable target for many different therapies. In the metastatic setting, prognosis has improved greatly with the use of anti-HER2 drugs such as trastuzumab, pertuzumab, and trastuzumab-emtansine. In the third line setting and beyond, several emerging treatments have shown benefits, including novel small molecule targeted agents and antibody-drug conjugates. Systemic treatment of brain metastases in HER2-positive patients and the role of endocrine-based treatment for patients with hormone receptor (HR) positive disease remain areas of research interest. This article will review the current approach to systemic management of metastatic HER2-positive breast cancer in Canada, and present novel treatments that may be available in the near future.