Anti-human Epidermal Growth Factor Receptor Research Articles

Unveiling the regulatory mechanisms of nimotuzumab on PD-L1 expression in head and neck squamous cell carcinoma patients: Implications for enhanced anticancer treatment strategies

The overexpression of programmed death ligand 1 (PD-L1) is associated with resistance to anticancer therapies and poor prognosis in patients with head and neck squamous cell carcinoma (HNSCC). Nimotuzumab, a humanized anti-epidermal growth factor receptor (EGFR) mAb, has been widely used clinically for treating several solid tumors. However, whether its anticancer effect involves a reduction in PD-L1 expression remains unclear. The current study aimed to investigate the regulatory effects and underlying mechanisms of nimotuzumab on PD-L1 expression in HNSCC both in vitro and in vivo. In vitro, nimotuzumab inhibited IFN-γ-induced PD-L1 upregulation at both the transcriptional and protein levels in the HNSCC cell lines. Subsequent mechanism research revealed that nimotuzumab suppressed IFN-γ-stimulated PD-L1 upregulation mainly by inhibiting phosphorylation of EGFR/MEK/ERK pathway, which was further validated by MEK and ERK inhibitors. In a HNSCC tumor-bearing model, nimotuzumab significantly decreased PD-L1 expression during tumor progression or chemotherapy, and this reduction was accompanied by increased sensitivity of the tumor to docetaxel and atezolizumab. Additionally, nimotuzumab reversed PD-L1 upregulation when combined with Taxol + Cisplatin (TP) induction chemotherapy regimens and improved the CD4+ and CD8+ T cells infiltration in HNSCC patients. These findings provide new insights into the anticancer mechanisms of nimotuzumab in HNSCC.

Breast Cancer Immunotherapy: A Clinical Review for the Plastic Surgeon.

Immunotherapy has transformed breast cancer management. However, it can be challenging to remain familiar with the adverse events, contraindications, and perioperative recommendations for each agent. We used FDALabel to identify all Food and Drug Administration-approved immunotherapies indicated for the treatment of breast cancer. We extracted details regarding warnings and precautions, indications, and adverse events from each package insert. We identified nine immunotherapies belonging to three classes: anti-human epidermal growth factor receptor 2 (HER2) agents, anti-programmed cell death protein 1 (PD-1) agents, and anti-trophoblast cell-surface antigen 2 (TROP-2) agents. Cardiotoxicity, including heart failure and cardiomyopathy, was common among those receiving anti-HER2 agents, and hypothyroidism was common among patients receiving the anti-PD-1 agent. The anti-TROP-2 agent was associated with diarrhea and neutropenia. Given the adverse event profile for each drug, we recommend preoperative evaluation components, including transthoracic echocardiography, liver function tests, and thyroid panels. We also indicate here which immunotherapies raise concern for venous thromboembolism, hematoma, and infection. Using data from clinical trials, we recommend a preoperative evaluation tailored to the immunotherapeutic regimen of individual patients.

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 8.9months, respectively). Progression-free survival was 9months in Tmab+pertuzumab (Pmab)+ERI, 4months in Tmab+ERI and 3.3months 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.

State-of-the-Art Advancements in Gastroesophageal Cancer Treatment: Harnessing Biomarkers for Precision Care.

Gastroesophageal cancers (GECs) represent a significant clinical challenge. For early resectable GEC, the integration of immune checkpoint inhibitors into the perioperative chemotherapy and chemoradiation treatment paradigms are being explored and showing promising results. Frontline management of metastatic GEC is exploring the role of targeted therapies beyond PD-1 inhibitors, including anti-human epidermal growth factor receptor 2 agents, Claudin 18.2 inhibitors, and FGFR2 inhibitors, which have shown considerable efficacy in recent trials. Looking ahead, ongoing trials and emerging technologies such as bispecific antibodies, antibody-drug conjugates, and adoptive cell therapies like chimeric antigen receptor T cells are expected to define the future of GEC management. These advancements signify a paradigm shift toward personalized and immunotherapy-based approaches, offering the potential for improved outcomes and reduced toxicity for patients with GEC.

Plant-Derived Anti-Human Epidermal Growth Factor Receptor 2 Antibody Suppresses Trastuzumab-Resistant Breast Cancer with Enhanced Nanoscale Binding.

Traditional monoclonal antibodies such as Trastuzumab encounter limitations when treating Human Epidermal Growth Factor Receptor 2 (HER2)-positive breast cancer, particularly in cases that develop resistance. This study introduces plant-derived anti-HER2 variable fragments of camelid heavy chain domain (VHH) fragment crystallizable region (Fc) KEDL(K) antibody as a potent alternative for overcoming these limitations. A variety of biophysical techniques, in vitro assays, and in vivo experiments uncover the antibody's nanoscale binding dynamics with transmembrane HER2 on living cells. Single-molecule force spectroscopy reveals the rapid formation of two robust bonds, exhibiting approximately 50 pN force resistance and bond lifetimes in the second range. The antibody demonstrates a specific affinity for HER2-positive breast cancer cells, including those that are Trastuzumab-resistant. Moreover, in immune-deficient mice, the plant-derived anti-HER2 VHH-FcK antibody exhibits superior antitumor activity, especially against tumors that are resistant to Trastuzumab. These findings underscore the plant-derived antibody's potential as an impactful immunotherapeutic strategy for treating Trastuzumab-resistant HER2-positive breast cancer.

Half-life extension via ABD-fusion leads to higher tumor uptake of an affibody-drug conjugate compared to PAS- and XTENylation.

A critical parameter during the development of protein therapeutics is to endow them with suitable pharmacokinetic and pharmacodynamic properties. Small protein drugs are quickly eliminated by kidney filtration, and in vivo half-life extension is therefore often desired. Here, different half-life extension technologies were studied where PAS polypeptides (PAS300, PAS600), XTEN polypeptides (XTEN288, XTEN576), and an albumin binding domain (ABD) were compared for half-life extension of an anti-human epidermal growth factor receptor 2 (HER2) affibody-drug conjugate. The results showed that extension with the PAS or XTEN polypeptides or the addition of the ABD lowered the affinity for HER2 to some extent but did not negatively affect the cytotoxic potential. The half-lives in mice ranged from 7.3 h for the construct including PAS300 to 11.6 h for the construct including PAS600. The highest absolute tumor uptake was found for the construct including the ABD, which was 60 to 160% higher than the PASylated or XTENylated constructs, even though it did not have the longest half-life (9.0 h). A comparison of the tumor-to-normal-organ ratios showed the best overall performance of the ABD-fused construct. In conclusion, PASylation, XTENylation, and the addition of an ABD are viable strategies for half-life extension of affibody-drug conjugates, with the best performance observed for the construct including the ABD.

Abstract PO3-17-07: Real-world experience with trastuzumab deruxtecan in patients with breast cancer: 6 month-interim analysis of an all-patient postmarketing surveillance in Japan

Abstract Background: Trastuzumab deruxtecan (T-DXd) is an anti-human epidermal growth factor receptor 2 (HER2) antibody-drug conjugate. T-DXd has shown great efficacy in HER2-positive breast cancer, hence receiving approval in Japan in March 2020. In Japan, all-patient postmarketing surveillance (PMS) is underway to evaluate the risk of interstitial lung disease/pneumonitis (ILD/p) in patients with breast cancer treated with T-DXd. Due to the limited generalizability of results from clinical trials, there is a need for more information about ILD/p in a real-world setting. Herein we present an interim analysis of the large-scale all-patient PMS. Methods: This is an observational, multicenter, all-patient PMS (jRCT1080225197) with an observation period of 18 months that enrolled all patients treated with T-DXd for recurrent/advanced HER2-positive breast cancer. Patients who initiated T-DXd treatment between May 2020 (launch date of T-DXd) and May 2021 were included in the interim analysis to ensure the observation period of 6 months from the initial treatment of T-DXd. This interim analysis is based on safety data from the first 6 months of 1204 patients. Data collected includes baseline characteristics and information on ILD/p. All potential ILD/p (identified based on the AE terms) reported by physicians were adjudicated by an independent ILD adjudication committee. The incidence of ILD/p was calculated from adjudicated drug-related ILD/p. Results: The interim analysis set included 1204 patients with median age of 60 years. Three of the 1204 patients (0.2%) received T-DXd as a first-line treatment, 30 (2.5%) as second-line, 1159 (96.3%) as third- line or later treatment. At baseline, 105 (8.7%) of patients had an Eastern Cooperative Oncology Group performance status (ECOG PS) 2 or greater, 8 (0.7%) had severe renal impairment (15≤ creatinine clearance (CLcr) < 30 mL/min), 4 (0.3%) had end-stage renal disease (CLcr < 15 mL/min), 5 (0.4%) had severe liver impairment (total bilirubin >4.5 mg/dL), and 32 (2.7%) had comorbid ILD/radiation pneumonitis. Those were defined as exclusion criteria in clinical trials of T-DXd. The median dose at the start of administration of T-DXd was 5.4 mg/kg (range:2.7-5.4). During the first 6 months from the initial treatment, T-DXd was discontinued in 403 (33.5%) of the 1204 patients. The most common reasons for discontinuation were disease progression in 232 (57.6%) of the discontinued 403 patients followed by ILD/p in 97 (24.1%) of the 403 patients. In the first 6 months, the incidence of all grade, grade ≥3, and grade 5 ILD/p were 8.2% (n=99), 1.7% (n=20) and 0.4% (n=5), respectively. The incidence of ILD/p stratified by baseline characteristics identified as potential risk factors of drug-related ILD/p is shown in Table. Conclusion: This is the first report demonstrating real-world experience with T-DXd in Japan. The interim analysis revealed useful information including patient and treatment profiles of T-DXd and the incidence of ILD/p during the first 6 months from the initial treatment in a real-world setting in Japan. The final analysis of the ongoing PMS is warranted for further evaluation. Incidence of interstitial lung disease/pneumonitis by patient baseline characteristics XX XX ILD/p: interstitial lung disease/pneumonitis, 95% CI: 95% confidence interval, CLCr: creatinine clearance using the Cockcroft-Gault equation * includes ILD/p, pulmonary fibrosis, radiation pneumonitis, chronic obstructive pulmonary disease, emphysema, and Asthma (Source: Powell CA, Modi S, Iwata H, et al. Pooled analysis of drug-related interstitial lung disease and/or pneumonitis in nine trastuzumab deruxtecan monotherapy studies. ESMO Open 2022;7(4):100554) Citation Format: Junji Tsurutani, Hideki Mizutani, Ayumi Tanabe. Real-world experience with trastuzumab deruxtecan in patients with breast cancer: 6 month-interim analysis of an all-patient postmarketing surveillance in Japan [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-17-07.

Abstract PO3-15-12: Expression and co-expression patterns of TROP2 and HER2 in breast cancer: implications for bispecific antibody-drug conjugate therapy

Abstract Introduction: Antibody-drug conjugates (ADCs) targeting trophoblast cell surface antigen 2 (TROP2), such as sacituzumab-govitecan and datopotamab-deruxtecan, have recently been developed. A preclinical study has reported the efficacy of anti-human epidermal growth factor receptor 2 (HER2) and TROP2 bispecific ADCs in treating HER2 and TROP2 co-expressing tumors, including HER2-low tumors in various solid tumors (Chengzhang Shang et al: AACR 2023). In this study, we aimed to evaluate the expression of TROP2 by immunohistochemistry (IHC) at different sites and investigate the changing status and co-expression of HER2 and TROP2 among breast cancer patients. Methods: We collected 244 archival paired samples of primary tumors and metastatic sites from 111 breast cancer patients treated in our hospital from 2000 to 2018. Estrogen receptor (ER), progesterone receptor (PgR), and HER2 status were determined from previous pathology reports. HER2 low was defined as HER2 IHC score of 1+ or 2+ with negative fluorescent in situ hybridization (ISH). In addition, we determined the expression of TROP2 using IHC assays and categorized the results based on the histochemical score (H-score). Results: Among the samples, ER+HER2- was 139, ER+HER2+ was nine, ER-HER2+ was eight, and triple-negative (TN) was 88. HER2 3+ or 2+ with ISH positive was 17, HER2 low was 112, HER2 negative was 115. The median TROP2 H-score was 10, with a mean of 37.5 (range: 0-265). Overall, 27% of the samples had H-score of 0, 73% had H-score of 1<, 47% had H-score of 10<, and 12% had H-score of 100< . No statistically significant association was observed between TROP2 expression and breast cancer subtypes (ER+HER2-; H-score of 0 24%, H-score of 1< 76%, H-score of 10< 44%, H-score of 100< 14%, TN; H-score of 0 30%, H-score of 1< 70%, H-score of 10< 54%, H-score of 100< 11%). On the other hand, samples from the metastatic site showed a higher rate of TROP-2 expression H-score of 1< compared to the primary site (primary site; H-score of 0 36%, H-score of 1< 64%, metastatic site; H-score of 0 18%, H-score of 1< 82%; p< 0.01). The rates of TROP2-positive expression defined as H-score of 1<, varied among the metastatic sites, with 100% in liver, 92% in brain, 89% in lymph nodes, 64% in lung, and 60% in bone. Regarding the co-expression of HER2 and TROP2, among HER2-positive samples, 35% had TROP2 H-score of 0, 24% had TROP2 H-score of 1<, and 41% had TROP2 H-score of 10<, while among HER2 low samples, 21% had TROP2 H-score of 0, 27% had TROP2 H-score of 1<, 39% had TROP2 H-score of 10<, and TROP2 H-score of 100< was found in 13% of patients. Based on the definition of co-expression such as TROP2 H-score of 1< and HER2 1+ or more, overall, 40% of the samples had co-expression of HER2 and TROP2, and the metastatic site had a higher rate of co-expression than the primary tumor (49%, 32% respectively, p=0.002). Conclusions: This study demonstrates that TROP-2 expression by IHC in breast cancer varies between primary and metastatic sites in breast cancer. Metastatic sites and specific organs show higher rate of TROP2 expression. Additionally, 40% of the samples had the co-expression of HER2 and TROP2, suggesting a potential target for future bispecific ADCs therapy. Citation Format: Mai Onishi, Tatsunori Shimoi, Yuki Kojima, Shu Yazaki, Taro Yamanaka, Rui Kitadai, Asuka Kawachi, Hitomi Okuma, Mai Hoshino, Ayumi Saito, Munehiro Ito, Aiko Maejima, Tadaaki Nishikawa, Kazuki Sudo, Emi Noguchi, Yasuhiro Fujiwara, Masayuki Yoshida, Kan Yonemori. Expression and co-expression patterns of TROP2 and HER2 in breast cancer: implications for bispecific antibody-drug conjugate therapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-15-12.

Abstract PS05-03: MagSense® HER2, a Molecularly Targeted Magnetic Resonance Imaging Agent for the Detection of Axillary Nodal Metastasis in Subjects with Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Breast Cancer

Abstract Background Precise nodal staging is critical in guiding systemic and regional treatments including surgery in the management of breast cancer. Regional nodal assessment includes axillary imaging (mostly by ultrasound) and lymph node sampling. Since imaging findings suggestive of nodal metastasis are based on size and morphologic changes and not specific to tumor type, pathologic confirmation through either biopsy or removal of sentinel lymph node (SLN) remains the gold standard. Imagion is developing the MagSense® HER2 Imaging Agent (MSH2IA), an anti-human epidermal growth factor receptor 2 (HER2) conjugated with iron oxide nanoparticles, for the detection of nodal metastasis in HER2+ breast cancer patients. MSH2IA is currently being investigated in a first-in-human phase 1 study (ACTRN12621000126819) in HER2+ breast cancer patients who are diagnosed to have suspicious nodes by conventional imaging. Methods The key objectives of the phase 1 study are safety and tolerability of MSH2IA and confirmation that MSH2IA drains to the axillary lymph nodes. The study also explores MSH2IA’s ability to detect metastatic nodes when used with magnetic resonance imaging (MRI), with tumor status assessed by standard tissue histopathology. All eligible subjects receive a 22.5 mg (iron equivalent) subareolar or peritumoral injection of MSH2IA. MRI of the axilla are obtained before and 24 to 72 hours after MSH2IA injection. Core biopsy or dissection of a node suspicious by ultrasound is obtained for histopathology assessments. After completing the first cohort of 6 subjects, the protocol was amended to include the insertion of an MRI compatible clip in a node suspicious by ultrasound to localize the suspicious node for core biopsy and postdose MRI scan. Review of MRI scans and histopathology are performed in respective central laboratories. Results Thirteen participants with HER2+ breast cancer have completed the study. MSH2IA appears safe and well tolerated. The imaging agent, as administered, is detectable by MRI and pathology, confirming that MSH2IA drains to the lymph nodes via the chosen route of administration. In postdose MRI scans, study central radiologists reported distinct and differentiable MRI appearance in morphologically normal and suspicious nodes. The presence of a distinct postdose MR image appearance was confirmed by a group of independent radiologists in a separate blinded review. While normal nodes appeared with homogeneous hypointensity, morphologically suspicious nodes showed partial irregular darkening and/or speckled heterogeneous hypointensity. In evaluable subjects, histopathology of the core biopsies obtained from the clipped nodes confirmed the presence of HER2+ nodal metastasis, providing preliminary evidence for node-level concordance between MRI vs pathology observations. Safety, imaging, and pathology results from all available subjects will be presented. This phase 1 study in Australia will be closing enrollment by July 31, 2023. A phase 2 study in the United States and elsewhere is being planned with the objectives of optimizing dose, schedule, and imaging parameters for best diagnostic performance for clinical utility. Conclusion Available data from the ongoing phase 1 study show that MSH2IA appears safe and drains to the axillary lymph nodes. MSH2IA displays a distinct and differentiable MRI appearance in nodes morphologically highly suspicious for tumor, which is confirmed to be HER2+ metastasis by histopathology by node level concordance. This data provides preliminary proof of principle for the mechanism of molecularly targeted MR imaging and suggests that MSH2IA has the potential to provide tumor-specific MR imaging not currently available in conventional axillary imaging. Citation Format: Jane Fox, Shanta Velaiutham, Natalie Yang, Eddie lau, Kowsi Murugappan, Beena Kumar, Alex Laslowski, Koushik Govindarajan, Steven Reich, Stephen Thomas, Nitika Neha, Marie Zhang, Isaac Bright. MagSense® HER2, a Molecularly Targeted Magnetic Resonance Imaging Agent for the Detection of Axillary Nodal Metastasis in Subjects with Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS05-03.

Association between human epidermal growth factor receptor 2 status, namely low and zero expression, and prognosis in hormone receptor-positive breast cancer: a single-center retrospective study.

The recently developed anti-human epidermal growth factor receptor 2 (HER2) therapy has substantially improved the prognosis of HER2-positive breast cancer. The DESTINY-Breast04 trial results showed that trastuzumab deruxtecan (T-DXd) significantly prolonged the survival of patients with HER2-low breast cancer, thus presenting a paradigm shift in anti-HER2 therapy. This may facilitate a change in the treatment strategy for HER2-low breast cancer. However, the implication of HER2-low in hormone receptor (HR)-positive breast cancer is unclear. In this retrospective study, we aimed to reveal the association between HER2 status, namely HER2-low and HER2-zero, and prognosis in HR-positive breast cancer. We collected the data of 247 patients with estrogen receptor (ER)-positive/HER2-negative breast cancer (159 with HER2-low and 88 with HER2-zero breast cancer) who underwent surgery. Patients were divided into HER2-low and HER2-zero groups. Univariate analysis was performed to evaluate the baseline characteristics using the Wilcoxon rank sum test and Fisher's exact test. Survival analysis of the HER2-low and HER2-zero groups was performed using the Kaplan-Meier method. The median observation period was 2,706 days, and the median period until recurrence was 1,380 days; 25 patients (10%) had recurrences. Age (P=0.004) and menopausal status (P=0.04) were significant variables in the univariate analysis of baseline characteristics. In the subgroup analysis of luminal A- and B-like breast cancers, there was a significant difference in overall survival (OS) only in patients with luminal A-like breast cancer, but relapse-free survival (RFS) of the HER2-low luminal B-like cancer subgroups tended to be relatively short. We inferred that the HER2-low and HER2-zero statuses do not affect the RFS and OS of patients with ER-positive breast cancer. The prognostic significance of HER2-low or HER2-zero status in luminal A- and B-like breast cancers might differ, and a new treatment strategy is required for the HER2-low subgroup.

Recurrent severe hypocalcemia following chemotherapy regimen changes in advanced breast cancer: two case reports

BackgroundAs an oncologic emergency related to abnormalities in calcium metabolism, hypercalcemia associated with paraneoplastic syndrome and bone metastases is well known. Meanwhile, the incidence of hypocalcemia is low, except in cases associated with bone-modifying agents used for bone metastases. Hypocalcemia induced by bone-modifying agents typically occurs early after the initial administration, and its incidence can be significantly reduced by preventive administration of calcium and vitamin D3 supplements.Case reportWe report two cases of recurrent severe hypocalcemia occurring during chemotherapy for metastatic breast cancer with multiple bone metastases.Case 1: A 35-year-old Japanese woman developed metastases in the bone, liver, and ovaries during postoperative endocrine therapy for invasive lobular carcinoma of the breast. She underwent chemotherapy and treatment with denosumab. She experienced recurrent episodes of severe hypocalcemia subsequent to a change in the chemotherapy regimen. Case 2: A 65-year-old Japanese woman encountered multiple bone metastases after postoperative anti-human epidermal growth factor receptor 2 therapy and during endocrine therapy for invasive ductal carcinoma of the breast. She underwent anti-human epidermal growth factor receptor 2 therapy and treatment with denosumab. She experienced recurrent severe hypocalcemia subsequent to a change in the chemotherapy regimen to letrozole + lapatinib, trastuzumab emtansine, and lapatinib + capecitabine.ConclusionsWe observed two cases of recurrent severe hypocalcemia in patients with advanced breast cancer and bone metastases after modifications to their therapy regimens. These cases differed from the typical hypocalcemia induced by bone-modifying agents. It is possible that antitumor drugs affect calcium and bone metabolism associated with bone metastases. While these cases are rare, it is crucial for oncologists to be aware of hypocalcemia not only at the initiation of bone-modifying agents but also throughout the entire antitumor therapy, as hypocalcemia can lead to fatal outcomes.

Abstract 2601: Potent antitumor activity of anti-HER2 antibody-topoisomerase I inhibitor conjugate based on self-immolative dendritic dimeric-linker

Abstract Antibody-drug conjugates (ADCs) are a rapidly expanding class of anticancer therapeutics, with 14 ADCs already approved worldwide. We developed unique linker technologies for the bioconjugation of drug molecules with controlled-release applications. We synthesized cathepsin-cleavable ADCs using a dimeric prodrug system based on a self-immolative dendritic scaffold, resulting in a high drug-antibody ratio (DAR) with the potential to reach 16 payloads due to its dendritic structure, increased stability in the circulation and efficient release profile of a highly cytotoxic payload at the targeted site. Using our novel cleavable linker technologies, we conjugated the anti-human epidermal growth factor receptor 2 (anti-HER2) antibody, trastuzumab, with topoisomerase I inhibitors, exatecan or belotecan. The newly synthesized ADCs were tested in vitro on mammary carcinoma cells overexpressing human HER2, demonstrating a substantial inhibitory effect on the proliferation of HER2-positive cells. Importantly, a single dose of our trastuzumab-based ADCs administered in vivo to mice bearing HER2-positive tumors, showed a dose-dependent inhibition of tumor growth and survival benefit, with the most potent antitumor effects observed at 10 mg/kg, which resulted in complete tumor regression and survival of 100% of the mice. Overall, our novel dendritic technologies using the protease-cleavable Val-Cit linker present an opportunity for the development of highly selective and potent controlled-released therapeutic payloads. This strategy could potentially lead to the development of novel and effective ADC technologies for patients diagnosed with HER2-positive cancers. Moreover, our proposed ADC linker technology can be implemented in additional medical conditions such as other malignancies as well as autoimmune diseases that overexpress targets, other than HER2. Citation Format: Yulia Liubomirski, Galia Tiram, Anna Scomparin, Samer Gnaim, Sayantan Das, Sachin Gholap, Liang Ge, Eilam Yeini, Omri Shelef, Arie Zauberman, Nir Berger, Doron Kalimi, Mira Toister-Achituv, Christian Schröter, Stephan Dickgiesser, Jason Tonillo, Min Shan, Carl Deutsch, Stanley Sweeney-Lasch, Doron Shabat, Ronit Satchi-Fainaro. Potent antitumor activity of anti-HER2 antibody-topoisomerase I inhibitor conjugate based on self-immolative dendritic dimeric-linker [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2601.

Abstract 1366: Dual immune checkpoint inhibition enhances the anti-tumor activity of trastuzumab deruxtecan in preclinical models

Abstract Background Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) composed of an anti-human epidermal growth factor receptor 2 (HER2) antibody, a cleavable tetrapeptide-based linker, and a topoisomerase I inhibitor payload. Recent clinical trials such as BEGONIA have highlighted the potential therapeutic benefit in combining T-DXd with immuno-oncology (IO) agents such as the PD-L1 inhibitor durvalumab. Here, we report preclinical findings demonstrating enhanced anti-tumor activity when T-DXd is combined with dual immune checkpoint inhibition. Methods HER2-expressing human cancer cell lines were treated in vitro with T-DXd and assessed for induction of immunogenic cell death (ICD) markers and expression of NK cell-activating ligands. Human macrophages and T cells were incubated with supernatants from treated cancer cells, and their activation status evaluated via flow cytometry. In vivo, the effects of T-DXd in combination with inhibitors of PD-L1, CTLA-4, and a monovalent bispecific anti-PD-1/TIGIT antibody - a murine surrogate of rilvegostomig - on tumor growth were evaluated in BALB/c mice bearing human HER2-low EMT6 murine mammary tumors. The anti-tumor activity of T-DXd in combination with volrustomig, a monovalent bispecific antibody targeting PD-1 and CTLA-4, was also assessed in hu-CD34+ NSG mice bearing HER2-low Caki-1 renal cell carcinoma tumors. Results In vitro, T-DXd induced ICD via DXd-mediated extracellular release of inflammatory mediators ATP and HMGB1, and cell surface exposure of calreticulin. This was associated with a greater than 2-fold increase in expression of NK cell-activating ligands, and activation of both macrophages and T cells. In immunocompetent mice bearing human HER2 expressing EMT6 tumors, T-DXd treatment drove tumor growth inhibition (53%, P <0.001) that was associated with an increase in tumoral T cells (2.6-fold, P <0.05) and increased CD8+ T cell expression of the immune checkpoints PD-1, TIGIT, and TIM-3. Tumor growth inhibition relative to vehicle-treated mice was enhanced when T-DXd was combined with inhibitors of PD-L1 (108%, P <0.001), PD-L1 plus CTLA-4 (172%, P <0.001), or a bispecific PD-1/TIGIT inhibitor (181%, P <0.001). Pharmacodynamic analysis revealed how the combination of T-DXd and PD-1/TIGIT inhibition increased tumoral NK cells (3.2-fold, P <0.001) and CD8+ T cells (3.8-fold, P <0.001) relative to vehicle. Consistent with findings in syngeneic models, the combination of T-DXd with a bispecific PD-1/CTLA-4 inhibitor also enhanced tumor growth inhibition in a humanised Caki-1 model (121%) compared to T-DXd alone (72%) (P <0.001). Conclusions These data provide insight into the clinical activity observed with T-DXd and provide scientific rationale for combination strategies with novel, bispecific IO agents targeting CTLA-4 or TIGIT in addition to the PD-1/PD-L1 axis. Citation Format: Liam Jenkins, Laura Kazlauskas, Matt Wilson, Scott A. Hammond, Theresa Proia, Jerome Mettetal. Dual immune checkpoint inhibition enhances the anti-tumor activity of trastuzumab deruxtecan in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1366.

Exploring Immunological Effects and Novel Immune Adjuvants in Immunotherapy for Salivary Gland Cancers.

Salivary gland cancer (SGC) is rare and comprises over 20 histological subtypes. Recently, clinical experience regarding immunotherapies for SGCs has been accumulating, yet their efficacy remains controversial. Understanding the tumor microenvironment (TME), including the expression of immune checkpoint molecules in SGC, is crucial to optimizing immunotherapy. In this review, we demonstrate that high-grade mucoepidermoid carcinoma and salivary duct carcinoma generally exhibit immune-hot TME with high immune cell infiltration, frequent genetic mutations, and robust immune checkpoint molecule expression. In contrast, adenoid cystic carcinomas exhibit an immune-cold TME. While the reported efficacy of immune checkpoint inhibitors (ICIs) for SGCs is generally poor, several studies showed promising clinical efficacy of ICIs, with an objective response rate ranging from 20.0-33.3%, indicating that ICIs might be beneficial for a specific population of SGC. Molecule-targeted therapies including anti-human epidermal growth factor receptor 2 and anti-androgen receptor therapies have shown promising clinical efficacy against SGC. Recent evidence indicates that these molecules could be targets for antigen-specific immunotherapies including chimeric antigen receptor-T therapy and cancer vaccines. This review discusses the current understanding and future directions of immunotherapies for SGCs, including ongoing clinical trials.

A Cell-Penetrating Peptide Improves Anti-HER2 Single-Chain Variable Fragment Internalization and Antitumor Activity against HER2-Positive Breast Cancer In Vitro and In Vivo.

Cell-penetrating peptides (CPPs) are invaluable tools for delivering various substances into cells by crossing biological membranes. However, the effects of cell-penetrating peptide fusion proteins on the biological activity of antibodies remain to be fully understood. Here, we engineered a recombinant protein, LP-scFv, which combines the single-chain variable region of anti-human epidermal growth factor receptor-2 with a novel and non-oxic cell-penetrating peptide as a leader peptide. The introduction of this leader peptide led to a more than twofold increase in the internalization efficiency of the single-chain antibody, as confirmed using microscopic analysis and flow cytometry. The effects of the single-chain antibodies and LP-scFv on cell viability were evaluated using the MTT assay. Both the single-chain antibodies and LP-scFv reduced the viability of BT474 and NCI-N87 cells in a dose-dependent manner while exhibiting minimal toxicity towards MCF-7 and MCF-10A cells. Further investigation into LP-scFv's mechanism revealed that the induced leader peptide does not alter the MAPK-ERK1/2 and PI3K/AKT pathways of single-chain antibodies. An enhanced antitumor activity was also confirmed in an NCI-N87 tumor xenograft model in mice with a reduction of 45.2% in tumor growth inhibition (vs. 23.1% for scFv) with a 50 mg/kg dose after orthotopic injection administration, which was equivalent to that of trastuzumab (vs. 55.7% for trastuzumab). Overall, these results indicate that LP-scFv exhibits significant permeation activity in HER2-positive cells to enhance the intracellular dose effect on antitumor activity in vitro and in vivo. This research lays the foundation for designing novel antibody-based therapies for cancer.

Effectiveness of [67Cu]Cu-trastuzumab as a theranostic against HER2-positive breast cancer.

To evaluate the imaging and therapeutic properties (theranostic) of 67Cu-labeled anti-human epidermal growth factor receptor II (HER2) monoclonal antibody trastuzumab against HER2-positive breast cancer (BC). We conjugated trastuzumab with p-SCN-Bn-NOTA, 3p-C-NETA-NCS, or p-SCN-Bn-DOTA, and radiolabeled with [67Cu]CuCl2. Immunoconjugate internalization was evaluated in BT-474, JIMT-1 and MCF-7 BC cells. In vitro stability was studied in human serum (HS) and Phosphate Buffered Saline (PBS). Flow cytometry, radioligand binding and immunoreactive fraction assays were carried out. ImmunoSPECT imaging of [67Cu]Cu-NOTA-trastuzumab was done in mice bearing BT-474, JIMT-1 and MCF-7 xenografts. Pharmacokinetic wasstudiedin healthy Balb/c mice while dosimetry was done in both healthy Balb/cand inathymic nudemice bearingJIMT-1 xenograft. The therapeutic effectiveness of [67Cu]Cu-NOTA-trastuzumab was evaluated in mice bearing BT-474 and JIMT-1 xenografts after a single intravenous (i.v.) injection of ~ 16.8MBq. Pure immunoconjugates and radioimmunoconjugates (> 95%) were obtained. Internalization was HER2 density-dependent with highest internalization observed with NOTA-trastuzumab. After 5days, in vitro stabilities were 97 ± 1.7%, 31 ± 6.2%, and 28 ± 4% in HS, and 79 ± 3.5%, 94 ± 1.2%, and 86 ± 2.3% in PBS for [67Cu]Cu-NOTA-trastuzumab, [67Cu]Cu-3p-C-NETA-trastuzumab and [67Cu]Cu-DOTA-trastuzumab, respectively. [67Cu]Cu-NOTA-trastuzumab was chosen for further evaluation. BT-474 flow cytometry showed low KD, 8.2 ± 0.2nM for trastuzumab vs 26.5 ± 1.6nM for NOTA-trastuzumab. There were 2.9 NOTA molecules per trastuzumab molecule. Radioligand binding assay showed a low KD of 2.1 ± 0.4nM and immunoreactive fraction of 69.3 ± 0.9. Highest uptake of [67Cu]Cu-NOTA-trastuzumab was observed in JIMT-1 (33.9 ± 5.5% IA/g) and BT-474 (33.1 ± 10.6% IA/g) xenograft at 120h post injection(p.i.). Effectiveness of theradioimmunoconjugate was also expressed as percent tumor growth inhibition (%TGI). [67Cu]Cu-NOTA-trastuzumab was more effective than trastuzumab against BT-474 xenografts (78% vs 54% TGI after 28days), and JIMT-1 xenografts (90% vs 23% TGI after 19days). Mean survival of [67Cu]Cu-NOTA-trastuzumab, trastuzumab and saline treatedgroups were > 90, 77 and 72days for BT-474 xenografts, while that of JIMT-1 were 78, 24, and 20days, respectively. [67Cu]Cu-NOTA-trastuzumab is a promising theranostic agent against HER2-positive BC.

Anti-HER2 Immunoliposomes: Antitumor Efficacy Attributable to Targeted Delivery of Anthraquinone-Fused Enediyne.

Although natural products are essential sources of small-molecule antitumor drugs, some can exert substantial toxicities, limiting their clinical utility. Anthraquinone-fused enediyne natural products are remarkably potent antitumor drug candidates, and uncialamycin and tiancimycin (TNM) A are under development as antibody-drug conjugates. Herein, a novel drug delivery system is introduced for TNM A using anti-human epidermal growth factor receptor 2 (HER2) immunoliposomes (ILs). Trastuzumab-coated TNM A-loaded ILs (HER2-TNM A-ILs) is engineered with an average particle size of 182.8±2.1nm and a zeta potential of 1.75±0.12mV. Compared with liposomes lacking trastuzumab, HER2-TNM A-ILs exhibited selective toxicity against HER2-positive KPL-4 and SKBR3 cells. Coumarin-6, a fluorescent TNM A surrogate, is encapsulated within anti-HER2 ILs; the resultant ILs have enhanced cellular uptake in KPL-4 and SKBR3 cells when compared with control liposomes. Furthermore, ILs loaded with more Cy5.5 accumulated in KPL-4 mouse tumors. A single HER2-TNM A-IL dose (0.02mgkg-1) suppressed the growth of HER2-positive KPL-4 mouse tumors without apparent toxicity. This study not only provides a straightforward method for the effective delivery of TNM A against HER2-positive breast tumors but also underscores the potential of IL-based drug delivery systems when employing highly potent cytotoxins as payloads.

A Cancer-Specific Monoclonal Antibody against HER2 Exerts Antitumor Activities in Human Breast Cancer Xenograft Models.

Monoclonal antibody (mAb)-based and/or cell-based immunotherapies provide innovative approaches to cancer treatments. However, safety concerns over targeting normal cells expressing reactive antigens still exist. Therefore, the development of cancer-specific mAbs (CasMabs) that recognize cancer-specific antigens with in vivo antitumor efficacy is required to minimize the adverse effects. We previously screened anti-human epidermal growth factor receptor 2 (HER2) mAbs and successfully established a cancer-specific anti-HER2 mAb, H2Mab-250/H2CasMab-2 (IgG1, kappa). In this study, we showed that H2Mab-250 reacted with HER2-positive breast cancer cells but did not show reactivity to normal epithelial cells in flow cytometry. In contrast, a clinically approved anti-HER2 mAb, trastuzumab, recognized both breast cancer and normal epithelial cells. We further compared the affinity, effector activation, and antitumor effect of H2Mab-250 with trastuzumab. The results showed that H2Mab-250 exerted a comparable antitumor effect with trastuzumab in the mouse xenograft models of BT-474 and SK-BR-3, although H2Mab-250 possessed a lower affinity and effector activation than trastuzumab in vitro. H2Mab-250 could contribute to the development of chimeric antigen receptor-T or antibody-drug conjugates without adverse effects for breast cancer therapy.

Exercise-based cardio-oncology rehabilitation for cardiotoxicity prevention during breast Cancer chemotherapy: The ONCORE randomized controlled trial

BackgroundBreast cancer (BC) treatment with anthracyclines and/or anti-human epidermal growth factor receptor-2 (HER2) antibodies is associated with an increased risk of cardiovascular disease complications, including cancer therapy-related cardiac dysfunction (CTRCD). While Cardio-Oncology Rehabilitation (CORe) programs including exercise have emerged to minimize these risks, its role in preventing CTRCD is unclear. ObjectivesWe investigated the effectiveness of an exercise-based CORe program in preventing CTRCD [left ventricular ejection fraction (LVEF) drop ≥10% to a value <53% or a decrease >15% in global longitudinal strain (GLS)]. Secondary outcomes examined changes in cardiac biomarkers, physical performance including peak oxygen consumption, psychometric and lifestyle outcomes. Safety, adherence, and patient satisfaction were also assessed. MethodsThis is a randomized controlled trial including 122 early-stage BC women receiving anthracyclines and/or anti-HER2 antibodies, randomized to CORe (n = 60) or usual care with exercise recommendation (n = 62). Comprehensive assessments were performed at baseline and after cardiotoxic treatment completion. The average duration of the intervention was 5.8 months. ResultsNo cases of CTRCD were identified during the study. LVEF decreased in both groups, but was significantly attenuated in the CORe group [−1.5% (−2.9, −0.1); p = 0.006], with no changes detected in GLS or cardiac biomarkers. The CORe intervention led to significant body mass index (BMI) reduction (p = 0.037), especially in obese patients [3.1 kg/m2 (1.3, 4.8)]. Physical performance and quality-of-life remained stable, while physical activity level increased in both groups. No adverse events were detected. ConclusionsThis study suggests that CORe programs are safe and may help attenuate LVEF decline in BC women receiving cardiotoxic therapy and reduce BMI in obese patients.

Potent antitumor activity of anti-HER2 antibody-topoisomerase I inhibitor conjugate based on self-immolative dendritic dimeric-linker

Antibody-drug conjugates (ADCs) are a rapidly expanding class of anticancer therapeutics, with 14 ADCs already approved worldwide. We developed unique linker technologies for the bioconjugation of drug molecules with controlled-release applications. We synthesized cathepsin-cleavable ADCs using a dimeric prodrug system based on a self-immolative dendritic scaffold, resulting in a high drug-antibody ratio (DAR) with the potential to reach 16 payloads due to its dendritic structure, increased stability in the circulation and efficient release profile of a highly cytotoxic payload at the targeted site. Using our novel cleavable linker technologies, we conjugated the anti-human epidermal growth factor receptor 2 (anti-HER2) antibody, trastuzumab, with topoisomerase I inhibitors, exatecan or belotecan. The newly synthesized ADCs were tested in vitro on mammary carcinoma cells overexpressing human HER2, demonstrating a substantial inhibitory effect on the proliferation of HER2-positive cells. Importantly, a single dose of our trastuzumab-based ADCs administered in vivo to mice bearing HER2-positive tumors, showed a dose-dependent inhibition of tumor growth and survival benefit, with the most potent antitumor effects observed at 10 mg/kg, which resulted in complete tumor regression and survival of 100% of the mice. Overall, our novel dendritic technologies using the protease-cleavable Val-Cit linker present an opportunity for the development of highly selective and potent controlled-released therapeutic payloads. This strategy could potentially lead to the development of novel and effective ADC technologies for patients diagnosed with HER2-positive cancers. Moreover, our proposed ADC linker technology can be implemented in additional medical conditions such as other malignancies as well as autoimmune diseases that overexpress targets, other than HER2.