Targeting Epidermal Growth Factor Receptor Research Articles

ASK120067 (limertinib) exerts pre-clinical anti-tumor activity by inhibiting EGFR exon20 insertion

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are classic strategies for the individualized treatment for patients with non-small cell lung cancer (NSCLC). However, EGFR exon20 insertion (EGFR 20ins) mutations, accounting for 6%–12% of all EGFR mutant cases in NSCLC, are generally resistant to the reversible EGFR TKIs (such as gefitinib and erlotinib), which makes them challenging drug-targets in lung cancer. In our previous study, we identified ASK120067 (limertinib) as a novel 3rd-generation EGFR TKI targeting EGFR T790M mutation with promising clinical activities. Here, we accessed the potency of ASK120067 on EGFR 20ins activation and evaluated its in vitro and in vivo anti-tumor activity against EGFR 20ins driven tumor models. We found that ASK120067 showed potent inhibitory activity on TKI-resistant EGFR 20ins kinase. In TKI-resistant EGFR 20ins-dependent BaF3 cells, it dose-dependently suppressed EGFR phosphorylation, impeded cell proliferation, and induced cell apoptosis with much superior efficacy to gefitinib and erlotinib. Moreover, oral administration of ASK120067 decreased the level of phospho-EGFR 20ins and caused significant tumor regression in EGFR 20ins BaF3 xenograft model. These results presented the pre-clinical anti-tumor efficacy of ASK120067 in EGFR 20ins models and highlighted the potential value of ASK120067 for the treatment of NSCLC patients harboring EGFR 20ins mutations.

MTDH-stabilized DDX17 promotes tumor initiation and progression through interacting with YB1 to induce EGFR transcription in Hepatocellular Carcinoma.

Metadherin (MTDH) is a well-established oncogene in various cancers including Hepatocellular Carcinoma (HCC). However, the precise mechanism through which MTDH promotes cancer-related signaling pathways in HCC remains unknown. In this study, we identified DDX17 as a novel binding partner of MTDH. Furthermore, MTDH increased the protein level of DDX17 by inhibiting its ubiquitination. We confirmed that DDX17 was a novel oncogene, with dramatically upregulated expression in HCC tissues. The increased expression of DDX17 was closely associated with vascular invasion, TNM stage, BCLC stage, and poor prognosis. In vitro and in vivo tests demonstrated that DDX17, a downstream target of MTDH, played a crucial role in tumor initiation and progression. Mechanistically, DDX17 acted as a transcriptional regulator that interacted with Y-box binding protein 1 (YB1) in the nucleus, which in turn drove the binding of YB1 to its target epidermal growth factor receptor (EGFR) gene promoter to increase its transcription. This in turn increased expression of EGFR and the activation of the downstream MEK/pERK signaling pathway. Our results identify DDX17, stabilized by MTDH, as a powerful oncogene in HCC and suggest that the DDX17/YB1/EGFR axis contributes to tumorigenesis and metastasis of HCC.

CTIM-23. DOSE ESCALATION TRIAL OF FC-ENGINEERED ANTI-CD40 MONOCLONAL ANTIBODY (2141-V11) ADMINISTERED INTRATUMORALLY WITH D2C7-IT VIA CONVECTION-ENHANCED DELIVERY (CED) FOR RECURRENT MALIGNANT GLIOMAS (RMGS)

Abstract BACKGROUND D2C7-IT, a novel immunotoxin-based cytotoxic therapy, targets epidermal growth factor receptor (EGFR) and mutant EGFR variant III. In preclinical studies, D2C7-IT kills tumor cells and prolongs survival, but is unable to generate cures in all animals. We hypothesized that immunosuppression in glioblastoma limits D2C7-IT efficacy. Eliminating glioblastoma immunosuppression via CD40 co-stimulation is anticipated to enhance D2C7-IT-induced antitumor responses. In murine glioma models, CED of D2C7-IT+αCD40 generated cures and long-term tumor-specific adaptive immunity. Hence, we are conducting a phase 1 trial of D2C7-IT+2141-V11 (αhuman-CD40) administered via CED in rMG patients. METHODS Eligibility includes adult patients with solitary supratentorial rMG (WHO grade 3/4); ≥ 4 weeks after chemotherapy, bevacizumab, or study drug; adequate organ function; and KPS ≥ 70%. Cohorts of 3 patients are treated with increasing doses of 2141-V11 to determine the maximum tolerated dose when administered sequentially following D2C7-IT (166,075 ng) via CED at 0.5 mL/hr. Five dose levels (DLs) are evaluated (2141-V11 at: #1: 0.70 mg; #2: 2.0 mg; #2**: 3.0 mg #2*: 4.0 mg; #3: 7.0 mg). RESULTS As of May 29, 2022, 13 patients were treated (3 patients on DL1, DL2, and DL2**; 2 patients on DL3 and DL2*). No dose-limiting toxicities were observed; however, lower DLs were added due to higher frequency of adverse events (AEs) expected with D2C7-IT+2141-V11 with DL3 and DL2* (fever, neurologic symptoms). All patients remain alive 0.7-10.6 months after therapy. Grade ≥ 2 AEs due to D2C7-IT+2141-V11 include: headache (grade 3, n = 1; grade 2, n = 4); pyramidal tract disorder (grade 3, n = 1; grade 2, n = 2); paresthesia (grade 3, n = 1); dysphasia (grade 3, n = 1); seizures (grade 2; n = 2); fever (grade 2; n = 2); and one each of grade 2 depressed level of consciousness, fatigue, and concentration impairment. Enrollment is ongoing. CONCLUSIONS Intratumoral administration of D2C7-IT+2141-V11 via CED is safe, encouraging efficacy results are observed.

ODP359 Thyrotropin secreting pituitary microadenoma and lung adenocarcinoma treated with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) Erlotinib and Osimertinib: a case report

Abstract Background Thyrotropin secreting pituitary adenoma (TSHoma) of the pituitary specific transcription factor-1 (PIT-1) lineage, is the rarest subtype of pituitary neuroendocrine tumours (pitNETs). TSHomas must be discriminated from primary hyperthyroidism and can cause morbidity through thyrotoxicosis or local mass effect. Serum alpha-subunit level may be used as a marker of tumour activity, as 50-85% of TSHoma patients have high serum alpha-subunit levels. First line treatment is surgical resection of the tumour. Medical therapy with somatostatin analogues or radiotherapy may be used for tumour control. Epidermal growth factor receptor (EGFR) expression has been demonstrated in pitNETs including corticotrophs, gonadotrophs, lactotrophs and somatotrophs. EGFR inhibiting agent, Lapatinib, has been investigated for treatment of prolactinomas and EGFR expression is implicated in tumorigenesis of corticotrophs. EGFR targeting tyrosine kinase inhibitors (TKIs) can be used first line to treat metastatic adenocarcinoma of the lung harbouring activating EGFR mutations. Case Report A non-smoking 53-year-old male of Middle Eastern heritage was seen in clinic with secondary hyperthyroidism on a background of metastatic adenocarcinoma of the lung and hypertension. The patient had no symptoms of hyperthyroidism and had no personal or family history of thyroid dysfunction. No new headaches or visual disturbance were reported. Physical exam showed brisk reflexes, no specific signs of hyperthyroidism or thyromegaly were seen. Thyroid function tests demonstrated a persistently elevated TSH 5.1mIU/L (0.4-4. 0), T4 21.8pmol/L (9-19) and T3 6.4pmol/L (2.6-6. 0) with negative anti- thyroid receptor, thyroperoxidase and thyroglobulin antibodies. Ultrasound of the thyroid was unremarkable. MRI revealed a well-circumscribed left anterior pituitary lesion of 5.4×6.8mm in size. Surgery was deferred as 3 months prior, he was diagnosed with stage 4 intrapulmonary adenocarcinoma of the lung with an exon-19 deletion mutation in the EGFR gene. He received stereotactic radiotherapy and EGFR targeted therapy using 100mg of Erlotinib daily, which increased to 200mg 6 months later. After 1 year of therapy, his adenocarcinoma progressed and he was transitioned to the 3 rd generation EGFR-TKI Osimertinib. Instead of undergoing the risk of pituitary surgery, a trial of EGFR therapy for its pleiotropic pituitary adenoma effects was decided. During the EGFR-TKI treatment period, alpha subunit levels have remained stable and serial MRI imaging at 1 year showed no interval pituitary adenoma growth. Conclusion This is a rare case of TSHoma identified during treatment of lung cancer with EGFR-TKIs. EGFR signalling is implicated in prolactinomas and corticotrophs though there is a paucity of data regarding TSHomas. To date, our patient has achieved radiological and biochemical stability in his TSHoma, with hyperthyroidism control on EGFR-TKI therapy, suggestive of a therapeutic benefit from EGFR signal blockade. Further studies are needed in larger cohorts to quantify EGFR expression in TSHomas and evaluate its possible role in pathogenesis. Presentation: No date and time listed

The anticancer effect of EGFR-targeting artificial microRNA controlled by SLPI promoter in nasopharyngeal carcinoma.

This study intends to use artificial microRNA (recombinant adenovirus vector) targeting epidermal growth factor receptor (EGFR) to inhibit the overexpressed EGFR in nasopharyngeal carcinoma, thereby inhibiting the proliferation and metastasis of nasopharyngeal carcinoma. The research group verified the expression of EGFR in nasopharyngeal carcinoma through databases, clinical tissues, and cellular pathways. The team first tested the transfection of the recombinant adenovirus by fluorescence microscopy. After adenovirus treatment with different multiplicity of infection (MOI), EGFR level and cell viability in cells were examined by Western blot and MTT assay. Next, the effects of adenovirus (Ad)-SLPI-EGFR on cell proliferation, migration, apoptosis, and related proteins were sequentially examined by EdU, scratch, Transwell, and Western blot. In vivo experiments were performed to evaluate the biological function of EGFR in nasopharyngeal carcinoma. All three validation pathways showed the increase in EGFR expression in nasopharyngeal carcinoma. Transfection tests showed that the SLPI promoter was specific in CNE2 cells. With the increase in MOI, the inhibition of EGFR expression and cancer cell viability by Ad-SLPI-EGFR was enhanced. Meanwhile, Ad-SLPI-EGFR effectively reduced the proliferation and metastasis of CNE2 cells and affected the expression of related proteins. Furthermore, Ad-SLPI-EGFR inhibited the invasion and metastasis of nasopharyngeal carcinoma in vivo. Ad-SLPI-EGFR inhibits the expression of EGFR in nasopharyngeal carcinoma cells, and finally achieves the purpose of inhibiting the proliferation and metastasis of cancer cells, which may provide novel targeted intervention for the treatment of nasopharyngeal carcinoma.

Picropodophyllotoxin Inhibits Cell Growth and Induces Apoptosis in Gefitinib-Resistant Non-Small Lung Cancer Cells by Dual-Targeting EGFR and MET.

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to the tyrosine kinase inhibitor gefitinib, however, the treatment becomes less effective over time by resistance mechanism including mesenchymal-epithelial transition (MET) overexpression. A therapeutic strategy targeting MET and EGFR may be a means to overcoming resistance to gefitinib. In the present study, we found that picropodophyllotoxin (PPT), derived from the roots of Podophyllum hexandrum, inhibited both EGFR and MET in NSCLC cells. The antitumor efficacy of PPT in gefitinib-resistant NSCLC cells (HCC827GR), was confirmed by suppression of cell proliferation and anchorage-independent colony growth. In the targeting of EGFR and MET, PPT bound with EGFR and MET, ex vivo, and blocked both kinases activity. The binding sites between PPT and EGFR or MET in the computational docking model were predicted at Gly772/Met769 and Arg1086/Tyr1230 of each ATP-binding pocket, respectively. PPT treatment of HCC827GR cells increased the number of annexin V-positive and subG1 cells. PPT also caused G2/M cell-cycle arrest together with related protein regulation. The inhibition of EGFR and MET by PPT treatment led to decreases in the phosphorylation of the downstream-proteins, AKT and ERK. In addition, PPT induced reactive oxygen species (ROS) production and GRP78, CHOP, DR5, and DR4 expression, mitochondrial dysfunction, and regulated involving signal-proteins. Taken together, PPT alleviated gefitinib-resistant NSCLC cell growth and induced apoptosis by reducing EGFR and MET activity. Therefore, our results suggest that PPT can be a promising therapeutic agent for gefitinib-resistant NSCLC.

Inhibition of IκB Kinase Is a Potential Therapeutic Strategy to Circumvent Resistance to Epidermal Growth Factor Receptor Inhibition in Triple-Negative Breast Cancer Cells.

Triple-negative breast cancer (TNBC) remains as an intractable malignancy with limited therapeutic targets. High expression of epidermal growth factor receptor (EGFR) has been associated with a poor prognosis of TNBC; however, EGFR targeting has failed with unfavorable clinical outcomes. Here, we performed a combinatorial screening of fifty-five protein kinase inhibitors with the EGFR inhibitor gefitinib in the TNBC cell line MDA-MB-231 and identified the IκB kinase (IKK) inhibitor IKK16 as a sensitizer of gefitinib. Cell viability and clonogenic survival assays were performed to evaluate the antiproliferative effects of the gefitinib and IKK16 (Gefitinib + IKK16) combination in TNBC cell lines. Western blot analyses were also performed to reveal the potential mode of action of this combination. In addition, next-generation sequencing (NGS) analysis was performed in Gefitinib+IKK16-treated cells. The Gefitinib+IKK16 treatment synergistically reduced cell viability and colony formation of TNBC cell lines such as HS578T, MDA-MB-231, and MDA-MB-468. This combination downregulated p-STAT3, p-AKT, p-mTOR, p-GSK3β, and p-RPS6. In addition, p-NF-κB and the total NF-κB were also regulated by this combination. Furthermore, NGS analysis revealed that NF-κB/RELA targets including CCL2, CXCL8, EDN1, IL-1β, IL-6, and SERPINE1 were further reduced and several potential tumor suppressors, such as FABP3, FADS2, FDFT1, SEMA6A, and PCK2, were synergistically induced by the Gefitinib-+IKK16 treatment. Taken together, we identified the IKK/NF-κB pathway as a potential target in combination of EGFR inhibition for treating TNBC.

Targeting EGFR Exon 20 Insertion-mutated Cancers – New Perspectives in Head and Neck Cancers – Lessons to Learn from Non-small Cell Carcinoma (NSCLC)

Mutations in the tyrosine kinase (TKD) domain of the epidermal growth factor receptor (EGFR) are involved in the unfavorable therapeutic response through resistance to targeted molecular therapy. Data from the clinical experience of non-small cell lung carcinoma (NSCLC) treatment demonstrate the benefit of tyrosine kinase inhibitors (TKIs) in cases of EGFR mutation. The next generation sequencing technique (NGS) allows the identification of hot spots involved in mutations, exon 20 insertion being associated with the unfavorable response. Exon 20 insertions are more common in head and neck squamous cell carcinoma (HNSCC) compared to NSCLC, which could explain a resistance to targeted therapy in head and neck cancers. Taking into account the data reported in the NSCLC, Amivantamab, a bi-specific EGFR-MET antibody with potential immune cell modulation of activity, but also other innovative therapies validated in exon 20 EGFR mutation could be part of the therapy of sino-nasal cancer, but also of other HNSCC sites exon 20 mutant EFGR.

Targeting Epidermal Growth Factor Receptor in Head and Neck Cancer.

Head and neck squamous cell carcinomas are rising in incidence worldwide, and despite the advent of improved surgical and radiation techniques, a substantial proportion of patients have disease recurrence, where systemic therapies are the mainstay of management. Recent advances in systemic therapy include the development of epidermal growth factor receptor- and programmed death 1-targeting drugs, which have produced incremental improvements in disease outcomes. However, for most patients, responses to treatment remain elusive because of primary or acquired resistance. Novel drugs and rational drug combinations need to be tested based on biomarker identification and preclinical science that will ultimately advance outcomes for our patients. This review focuses on efforts untaken for epidermal growth factor receptor targeting in head and neck squamous cell carcinoma to date.

MA07.08 JIN-A02, a Highly Effective 4th Generation EGFR-TKI, Targeting EGFR C797S Triple Mutation in NSCLC

Among non-small cell lung cancer (NSCLC) gene mutations, epidermal growth factor receptor (EGFR) mutations are the most common and occur in approximately 50% of Asian NSCLC.1) Although EGFR-targeted therapeutics have been widely used for the treatment of EGFR-mutant lung cancer, acquired resistance invariably develops after 12-18 months in patients.2) EGFR C797S mutation, located within the tyrosine kinase domain, was recently reported to be a potential mechanism of resistance to irreversible EGFR inhibitors.

Nanoscale Mapping of EGFR and c-MET Protein Environments on Lung Cancer Cell Surfaces via Therapeutic Antibody Photocatalyst Conjugates.

Receptor tyrosine kinases are involved in essential signaling roles that impact cell growth, differentiation, and proliferation. The overexpression or mutation of these proteins can lead to aberrant signaling that has been directly linked to a number of diseases including cancer cell formation and progression. This has led to intense clinical focus on modulating RTK activity through direct targeting of signaling activity or cell types harboring aberrant RTK behavior. In particular, epidermal growth factor receptor (EGFR) has attracted intense clinical attention due to the impact of inhibiting this RTK on tumor growth. However, mutations incurred through targeting EGFR have led to therapeutic resistance that involves not only direct mutations to the EGFR protein but also the involvement of other RTKs, such as c-MET, that can overcome therapeutic-based EGFR inhibition effects. This has, not surprisingly, led to co-targeting strategies of RTKs such as EGFR and c-MET to overcome resistance mechanisms. While the ability to co-target these proteins has led to success in the clinic, a more comprehensive understanding of their proximal environments, particularly in the context of therapeutic modalities, could further enhance both our understanding of their signaling biology and provide additional avenues for targeting these surface proteins. Thus, to investigate EGFR and c-MET protein microenvironments, we utilized our recently developed iridium photocatalyst-based microenvironment mapping technology to catalog EGFR and c-MET surface environments on non-small cell lung cancer cell lines. Through this approach, we enriched EGFR and c-MET from the cell surface and identified known EGFR and c-MET associators as well as previously unidentified proximal proteins.

Oxidized tea polyphenol (OTP-3) targets EGFR synergistic nimotuzumab at inhibition of non-small cell lung tumor growth

Aberrant activation of epidermal growth factor receptor (EGFR) plays a pivotal role in cancer initiation and progression and has gained attention as an anticancer drug target. EGFR monoclonal antibodies have been canonically used in non-small cell lung cancer (NSCLC) treatment. However, a basal level of ligand-independent EGFR signaling pro-survival properties limit the clinical efficacy of EGFR monoclonal antibodies. Therefore, targeting EGFR by inducing degraders is a promising approach towards improving therapeutic efficacy and augmenting the effect of nimotuzumab. Here we describe rational discovery of OTP-3, an oxidized (−)-Epigallocatechin gallate (EGCG) derivative that elicits potent anticancer activity in EGFR wild type NSCLC. Mechanistic studies disclosed that OTP-3 directly binds to EGFR extracellular domain decreases EGF and EGFR binding affinities by combination with nimotuzumab. Molecular docking studies revealed that OTP-3-EGFR is a very stable complex. Further analyses showed that nimotuzumab combined with OTP-3 resulted in significantly promoted EGFR degradation and repressed downstream survival pathways. Accordingly, OTP-3 combined with nimotuzumab significantly inhibits tumor growth through degrading EGFR in vivo. Thus, OTP-3 can also serve as an effective therapeutic agent in NSCLC where it can augment the effects of nimotuzumab, a valuable property for combination agents.

EGF Receptor Signaling Modulates YAP Activation and Promotes Experimental Proliferative Vitreoretinopathy.

PurposeBoth epidermal growth factor receptor (EGFR) and the Yes-associated protein (YAP) signaling pathway are implicated in cell proliferation and differentiation. In this study, we explored whether the formation of proliferative vitreoretinopathy (PVR) depends on the interaction of the EGFR receptor and YAP pathway.MethodsWe studied the effects of EGFR and YAP activation on retinal fibrosis in a PVR mouse model as well as in knockout mice (conditional deletion of EGFR or YAP specifically in RPE cells). Reversal and knockdown experiments were performed to induce a model of ARPE-19 cells treated with TGF-β2 in vitro. The effect of EGFR/YAP signaling blockade on the PVR-induced cell cycle and TGF-β2–induced ARPE-19 cell activation was determined.ResultsThe EGFR inhibitor erlotinib or conditional deletion of EGFR attenuated YAP activation and decreased the expression of YAP and its downstream target Cyr61 and of connective tissue growth factor in vivo and in vitro. EGFR-PI3K-PDK1 signaling induced by PVR promoted YAP activation and cell cycle progression. Furthermore, activated EGFR signaling bypassed RhoA to increase the protein levels of YAP, C-Myc, CyclinD1, and Bcl-xl.ConclusionsOur work highlights that EGFR-PI3K-PDK1–dependent YAP activation plays a crucial role in the formation of PVR. Targeting EGFR and the YAP pathway provides promising therapeutic treatments for PVR.

Analysis of the Effcacy and Safety of Amivantamab in Non-small Cell Lung Cancer Patients with EGFR/MET Gene Abnormalities: A Single Center's Experience

背景与目的表皮生长因子受体（epidermal growth factor receptor, EGFR）和细胞间质上皮转换因子（cellular-mesenchymal to epithelial transition factor, c-Met）是非小细胞肺癌（non-small cell lung cancer, NSCLC）中常见的变异基因，都是受体酪氨酸激酶，在下游信号转导方面具有协同作用。针对EGFR和c-Met通路的靶向药物联合应用后，能够阻断PI3K/AKT/mTOR途径和Ras/Raf/Mek途径，限制补偿通路激活，发挥抗肿瘤作用。以Amivantamab为代表的EGFR和c-Met双特异性抗体新型药物能同时阻断两条信号通路，在肺癌临床研究中展现出良好前景。然而目前国内应用较少，相关经验缺乏。本研究将介绍我中心Amivantamab疗效数据和不良反应处理经验，探讨此类药物对我国EGFR/MET基因异常NSCLC的应用价值。方法收集2020年8月-2021年12月于我院接受Amivantamab治疗的晚期NSCLC病例的临床数据，分析其治疗反应率、生存和不良反应。结果本研究共纳入15例患者，其中Amivantamab单药治疗6例，Amivantamab联合Lazertinib治疗9例。治疗后7例（46.7%）达部分缓解（partial response, PR），7例（46.7%）达疾病稳定（stable disease, SD），1例（6.7%）达疾病进展（progressive disease, PD），总体客观缓解率（objective response rate, ORR）为46.7%，总体疾病控制率（disease control rate, DCR）为93.3%。7例EGFR外显子20插入突变患者中，2例（28.6%）达PR，5例（71.4%）达SD，DCR为100.0%，中位缓解持续时间（duration of response, DOR）未成熟，2例PR者仍持续缓解。5例奥希替尼耐药的患者中，2例（40.0%）达PR，3例（60.0%）达SD，DCR为100.0%，中位DOR未成熟，1例PR者仍持续缓解。中位随访时间为8.7个月（0.9个月-18.6个月），截至最后一次随访，共有6例患者发生疾病进展，3例患者死亡，中位无进展生存期和中位总生存期未成熟。常见的不良事件为皮疹（86.7%），甲沟炎（80.0%）和输液反应（60.0%），多为1级-2级。3级及以上不良反应包括皮疹（33.3%），转氨酶升高（13.3%）、水肿（6.7%）、血栓栓塞（6.7%）、间质性肺炎（6.7%）和血小板减低（6.7%）。结论Amivantamab对EGFR外显子20插入突变和奥希替尼耐药的中国晚期NSCLC治疗有效，与国外疗效数据相仿。整体安全性可耐受，需重点关注皮疹、甲沟炎、输液反应等不良反应。

EGF Receptor-Targeting Cancer Therapy Using CD47-Engineered Cell-Derived Nanoplatforms.

IntroductionAvoiding phagocytic cells and reducing off-target toxicity are the primary hurdles in the clinical application of nanoparticles containing therapeutics. For overcoming these errors, in this study, nanoparticles expressing CD47 proteins inhibiting the phagocytic attack of immune cells were prepared and then evaluated as an anti-cancer drug delivery vehicle.MethodsThe CD47+ cell-derived nanoparticles (CDNs) were prepared from the plasma membranes of human embryonic kidney cells transfected with a plasmid encoding CD47. And the doxorubicin (DOX) was loaded into the CDNs, and anti-EGF receptor (EGFR) antibodies were conjugated to the surface of the CDNs to target tumors overexpressing EGFR.ResultsThe CD47+iCDNs-DOX was successfully synthesized having a stable structure. The CD47+CDNs were taken up less by RAW264.7 macrophages compared to control CDNs. Anti-EGFR CD47+CDNs (iCDNs) selectively recognized EGFR-positive MDA-MB-231 cells in vitro and accumulated more effectively in the target tumor xenografts in mice. Moreover, iCDNs encapsulating doxorubicin (iCDNs-DOX) exhibited the highest suppression of tumor growth in mice, presumably due to the enhanced DOX delivery to tumor tissues, compared to non-targeting CDNs or CD47- iCDNs.DiscussionThese results suggest that the clinical application of biocompatible cell membrane-derived nanocarriers could be facilitated by functionalization with macrophage-avoiding CD47 and tumor-targeting antibodies.

MiR-335 promotes corneal neovascularization by Targeting EGFR

BackgroundCorneal neovascularization (CRNV) is a severe threat to the vision of people. MicroRNA-335 (miR-335) has the function of facilitating angiogenesis. However, whether miR-335 regulates the progression of CRNV remains unclear.MethodsThe miR-335 expressions in CRNV rats induced by corneal suture and HUVECs induced by b-FGF were detected by quantitative real-time PCR. For the miR-335 function, wound healing and tube formation assays were performed. For the miR-335 mechanism, a dual-luciferase reporter gene assay was conducted. Besides, for the epidermal growth factor receptor (EGFR) function, Cell Counting Kit-8 and wound healing assays were performed. Meanwhile, the rescue assay was used to assess the miR-335/EGFR function in the migration and angiogenesis of b-FGF-treated HUVECs.ResultsFunctionally, the miR-335 knockdown weakened the migration and angiogenesis of b-FGF-treated HUVECs, while the miR-335 overexpression showed an opposite trend. Mechanistically, miR-335 interacted with EGFR and negatively regulated the expression of EGFR. The rescue assay illustrated that miR-335 regulated the migration and angiogenesis of b-FGF-treated HUVECs through EGFR.ConclusionsIn general, our data confirmed that miR-335 facilitated the process of CRNV by targeting EGFR.

Abstract 1772: EGFR signaling as a mechanism of resistance to CDK4/6 inhibitors in Palbociclib-resistant ER+ breast cancer cells

Abstract Breast cancer driven by estrogen receptor (ER) is responsible for approximately 60-70% of cases among women. Selective inhibition of cyclin-dependent kinases 4 and 6 (CDK4/6) and ER signaling is now standard-of-care therapy for ER positive (ER+) metastatic breast cancer. CDK4/6 inhibitors, including palbociclib (PD), used in combination with endocrine therapy have shown improvement in progression-free survival compared to endocrine therapy alone in the metastatic setting. However, the inevitable development of acquired resistance significantly limits the efficacy of this targeted therapy. In ER+ breast cancer resistant cells, rewired signaling driven by different oncogenes, including the epidermal growth factor receptor (EGFR), overcomes the inhibition of CDK4/6 by PD, which, in turn, allows cell cycle progression contributing to PD-resistance. We investigated the dependency of ER+ breast cancer cell lines sensitive and resistant to PD on EGFR signaling in vitro. We evaluated the expression and activity of EGFR in two different matching pairs of ER+ palbociclib-sensitive (pS) and palbociclib-resistant (pR) breast cancer cell lines (MCF7 and T47D) and observed elevated EGFR expression in MCF7/pR cells. Increased EGFR expression in MCF7/pR cells correlated with elevated ER alpha phosphorylation at S118 and S167 sites, suggesting a direct cross-talk between EGFR and ER signaling in PD-resistant cells. Serum starvation significantly decreased EGFR activity, cdk2 and cyclin D1 expression in both MCF7 and T47D PD-resistant cells compared to the parental cell lines, confirming their dependency on the presence of growth factors. Notably, stimulation with EGF promoted ER phosphorylation and expression of cell cycle related targets: cdk2, cyclin E and wee1 in both MCF7 and T47D cell lines sensitive and resistant to PD. Furthermore, stimulation with estrogen promoted EGFR activation in MCF7/pS and MCF7/pR cells, indicating a direct cross-regulation between these molecular targets. Further, exposure to the EGFR inhibitor erlotinib dramatically inhibited the proliferation of MCF7/pR cells compared to the parental cells, suggesting that EGFR could be an important bypass signaling regulator contributing to resistance to PD. We found that dual treatment with erlotinib and PD significantly inhibited Rb phosphorylation in MCF7/pR cells improving the effect of PD on cell cycle arrest. Moreover, dual treatment of MCF7/pR cells attenuated ER expression suggesting the higher dependency of ER signaling on EGFR activity in resistant cells. Taken together, our findings suggest that EGFR signaling is a mechanism of resistance in ER+ cell lines with acquired resistance to PD in vitro and that EGFR targeting can be a promising approach to improve palbociclib efficacy in breast cancer patients. Citation Format: Nadiia Lypova, Lilibeth Lanceta, Susan M. Dougherty, Jason A. Chesney, Yoannis Imbert-Fernandez. EGFR signaling as a mechanism of resistance to CDK4/6 inhibitors in Palbociclib-resistant ER+ breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1772.

Abstract 5423: Translational PK/PD/efficacy modeling and efficacious human dose prediction for a first-in-class MUC1-EGFR (M1231) bispecific antibody drug conjugate

Abstract Introduction: M1231 is a first-in-class bispecific antibody drug conjugate (ADC) targeting mucin-1 (MUC1) and epidermal growth factor receptor (EGFR), that is conjugated with a novel hemiasterlin-related microtubule inhibitor payload. Following dose, M1231 binds to EGFR and co-binds to tumor-associated hypoglycosylated MUC1, internalizes into the tumor cell and traffics to lysosomes where the payload is enzymatically released to affect cell viability. Methods: A Multi-scale Systems Pharmacology model was developed to account for the ADC’s disposition and interactions with the underlying physiologic system, resulting in intracellular payload release in tumor cells to drive tumor growth inhibition (TGI). An in vitro model quantified ADC internalization and lysosomal trafficking in the MUC1 and EGFR-expressing cancer cell lines MDA-MB-468 and OVCAR-3. TGI was assessed in mice bearing MUC1-tumors from the squamous NSCLC patient-derived xenograft model, LUX003. Pharmacokinetics in cynomolgus monkeys was modeled using a Target Mediated Drug Disposition model and was allometrically scaled to humans. Data Summary: All preclinical modeling results were integrated and scaled to simulate plasma M1231 concentrations to predict the human dose and corresponding exposures. Tumor stasis was estimated to begin at a dose of 2.4 mg/kg every 3 weeks (Q3W) with a maximum tumor regression achieved at a dose of 4.3 mg/kg Q3W. Conclusions: The quantitative systems pharmacology model-based efficacious dose prediction range of 2.4 mg/kg to 4.3 mg/kg dosed Q3W informed the design of the ongoing M1231 first-in-human trial (NCT04695847). Citation Format: Anup Zutshi, Berend Neuteboom, Seema Kumar, Willem Sloot, Christine Knuehl, Julia Dotterweich, Jianguo Ma, Christiane Amendt, Karthik Venkatakrishnan, Taeshin Park, John Pappas, Kyoung-Ae Kim. Translational PK/PD/efficacy modeling and efficacious human dose prediction for a first-in-class MUC1-EGFR (M1231) bispecific antibody drug conjugate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5423.

Targeting EGFR Exon 20 Insertion Mutation in Non-small cell Lung Cancer: Amivantamab and Mobocertinib.

To evaluate clinical data regarding the use of amivantamab and mobocertinib for epidermal growth factor receptor (EGFR) exon 20 insertion mutation non-small cell lung cancer (NSCLC) and assess their potential impact on the care of patients. A comprehensive literature search of PubMed and Clinicaltrials.gov was conducted using the terms amivantamab, Rybrevant, JNJ-61186372, mobocertinib, Exkivity, TAK-788. Relevant English-language clinical trials were evaluated. Amivantamab and mobocertinib were Food and Drug Administration (FDA) approved based on phases 1 and 2 studies. Amivantamab demonstrated an overall response rate (ORR) of 40% and median progression-free survival (PFS) of 8.3 months. Patients commonly experienced rash (86%), paronychia (45%), and stomatitis (21%). Mobocertinib demonstrated an ORR of 28% and median PFS of 7.3 months in phase 1/2 study. Patients frequently experienced diarrhea (91%), rash (45%), and paronychia (38%). Cardiac monitoring is recommended with mobocertinib due to risk of QTc prolongation and cardiac failure. For NSCLC patients who possess an EGFR exon 20 insertion mutation, amivantamab and mobocertinib are indicated as second-line therapy. Ongoing studies are evaluating these therapies as first-line monotherapy and as part of combination regimens in multiple cancer types. Dosage forms, drug interactions, and patient comorbidities should be considered when deciding which of the 2 agents may be most appropriate. Amivantamab and mobocertinib target an uncommon NSCLC mutation that has historically marked a poor prognosis because of innate resistance to previously approved EGFR tyrosine kinase inhibitors. Promising results from early phase trials supported accelerated FDA approval.

Effectiveness of nationwide insurance coverage for next-generation sequencing in advanced non–small cell lung cancer: A real-world data study.

9134 Background: Next-generation sequencing (NGS) has been covered by Korean national health insurance since March 2017 for patients with advanced non-small cell lung cancer (NSCLC). We explored the clinical and socioeconomic impact of NGS compared with that of a single gene test (SGT) alone. Methods: From the nationwide database, we identified patients who 1) are diagnosed with advanced NSCLC classified as a distant disease using Summary Stage between March 1, 2017, and December 31, 2018; 2) had NGS or SGT within 2 months after diagnosis of advanced NSCLC. Patients with squamous cell carcinoma were excluded. We conducted multivariate logistic regression to identify factors (e.g., age, sex, Charlson comorbidity index, insurance type, year of diagnosis, and region and type of hospital with the initial diagnosis) affecting the performance of NGS. Further, we divided the cohort into subgroups based on whether patients received treatment targeting epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations (group A) or not (group B). We conducted 1:5 propensity score matching for each group to minimize the impact of confounding factors. The median overall survival and the adjusted hazard ratio (aHR) for death were estimated using the Kaplan-Meier method and the Cox proportional hazard model, respectively. We calculated the total medical cost, and per patient per year (PPPY) cost adjusted for the survival period. Results: Among 10,247 patients with advanced NSCLC, 768 patients were identified as group A and 1,596 as group B after matching. Old age, low household income, and rural region were factors negatively impacting on having NGS tests. In Group A, we did not find a significant difference in survival outcome between the NGS cohort and the SGT cohort (median survival 31.6 vs. 27.5 months, P =.331; aHR 0.80, P =.204). In contrast, significantly favorable survival was observed for the NGS group in Group B (median survival 14.1 vs. 9.5 months, P =.023; aHR 0.80, P =.009). Although the total medical cost was higher in the NGS group ($39,145) than the SGT group ($36,207) for Group B, the PPPY cost was lower in the NGS group ($57,502 and $63,293, respectively). Conclusions: Socioeconomic factors hampering the implementation of NGS were identified. Lowering the barrier by covering the NGS cost publicly in a specific clinical setting may have survival and cost-benefit in patients with advanced NSCLC.