Preclinical Models Of Lung Cancer Research Articles

Inhibition of ULK1/2 and KRASG12C controls tumor growth in preclinical models of lung cancer

Inhibition of ULK1/2 and KRASG12C controls tumor growth in preclinical models of lung cancer

Inhibition of ULK1/2 and KRASG12C controls tumor growth in preclinical models of lung cancer.

Mutational activation of KRAS occurs commonly in lung carcinogenesis and, with the recent U.S. Food and Drug Administration approval of covalent inhibitors of KRASG12C such as sotorasib or adagrasib, KRAS oncoproteins are important pharmacological targets in non-small cell lung cancer (NSCLC). However, not all KRASG12C-driven NSCLCs respond to these inhibitors, and the emergence of drug resistance in those patients who do respond can be rapid and pleiotropic. Hence, based on a backbone of covalent inhibition of KRASG12C, efforts are underway to develop effective combination therapies. Here, we report that the inhibition of KRASG12C signaling increases autophagy in KRASG12C-expressing lung cancer cells. Moreover, the combination of DCC-3116, a selective ULK1/2 inhibitor, plus sotorasib displays cooperative/synergistic suppression of human KRASG12C-driven lung cancer cell proliferation in vitro and superior tumor control in vivo. Additionally, in genetically engineered mouse models of KRASG12C-driven NSCLC, inhibition of either KRASG12C or ULK1/2 decreases tumor burden and increases mouse survival. Consequently, these data suggest that ULK1/2-mediated autophagy is a pharmacologically actionable cytoprotective stress response to inhibition of KRASG12C in lung cancer.

Inhibition of ULK1/2 and KRAS G12C controls tumor growth in preclinical models of lung cancer.

Mutational activation of KRAS occurs commonly in lung carcinogenesis and, with the recent FDA approval of covalent inhibitors of KRAS G12C such as sotorasib or adagrasib, KRAS oncoproteins are important pharmacological targets in non-small cell lung cancer (NSCLC). However, not all KRAS G12C -driven NSCLCs respond to these inhibitors, and the emergence of drug resistance in those patients that do respond can be rapid and pleiotropic. Hence, based on a backbone of covalent inhibition of KRAS G12C , efforts are underway to develop effective combination therapies. Here we report that inhibition of KRAS G12C signaling increases autophagy in KRAS G12C expressing lung cancer cells. Moreover, the combination of DCC-3116, a selective ULK1/2 inhibitor, plus sotorasib displays cooperative/synergistic suppression of human KRAS G12C -driven lung cancer cell proliferation in vitro and superior tumor control in vivo . Additionally, in genetically engineered mouse models of KRAS G12C -driven NSCLC, inhibition of either KRAS G12C or ULK1/2 decreases tumor burden and increases mouse survival. Consequently, these data suggest that ULK1/2-mediated autophagy is a pharmacologically actionable cytoprotective stress response to inhibition of KRAS G12C in lung cancer.

Evaluation of antitumor potential of an anti-glypican-1 monoclonal antibody in preclinical lung cancer models reveals a distinct mechanism of action.

The main objective of this study was to investigate the antitumor effect of a mouse anti-human glypican-1 (GPC1) monoclonal antibody (mAb) on non-small cell lung carcinoma (NSCLC) and associated molecular mechanisms. The anti-proliferative and anti-migratory activities of anti-GPC1 mAb were examined in A549 and H460 NSCLC cells and LL97A lung fibroblasts. The inhibitory effect of anti-GPC1 mAb on tumor growth was evaluated in an orthotopic lung tumor model. The in vitro study showed that anti-GPC1 mAb profoundly inhibited the anchorage-independent growth of A549 and H460 NSCLC cells and exhibited relatively high cytotoxic activities towards LL97A lung fibroblasts, A549/LL97A and H460/LL97A coculture spheroids. Moreover, anti-GPC1 mAb significantly decreased the expression of phospho-Src (p-Src; Tyr416), p-Akt (Ser473) and β-catenin in the co-cultured LL97A lung fibroblasts, and the expression of phospho-mitogen-activated protein kinase kinase (p-MEK; Ser217/221) and phospho-90 kDa ribosomal s6 kinase (p-p90RSK; Ser380) in co-cultured A549 cells. When anti-GPC1 mAb was administered to tumor-bearing mice, the inhibitory effect of anti-GPC1 mAb on the orthotopic lung tumor growth was not statistically significant. Nonetheless, results of Western blot analysis showed significant decrease in the phosphorylation of fibroblast growth factor receptor 1 (FGFR1) at Tyr766, Src at Tyr416, extracellular signal-regulated kinase (ERK) at Thr202/Tyr204, 90 kDa ribosomal S6 kinase (RSK) at Ser380, glycogen synthase kinases 3α (GSK3α) at Ser21 and GSK3β at Ser9 in tumor tissues. These data implicate that anti-GPC1 mAb treatment impairs the interaction between tumor cells and tumor associated fibroblasts by attenuating the paracrine FGFR signal transduction. The relatively potent cytotoxicity of anti-GPC1 mAb in lung fibroblasts and its potential inhibitory effect on the paracrine FGFR signal transduction warrant further studies on the combined use of this mAb with targeted therapeutics to improve therapeutic outcomes in lung cancer.

A phase 1, first-in-human, open-label study evaluating the safety, tolerability, pharmacokinetics, and efficacy of TT125-802 in patients with advanced solid tumors.

TPS3171 Background: TT125-802 is a selective, potent, orally bioavailable small molecule inhibitor of the bromodomain of CBP and p300, two highly homologues lysine acetyltransferases. CBP/p300 act as transcriptional co-activators with multiple domains and functions, including well-documented roles in cell cycle regulation and several critical tumorigenic pathways (1-3). TT125-802 has shown mono-therapy efficacy in preclinical models of castration-resistant prostate cancer, KRAS-mutated colorectal and non-small cell lung cancer (4,5). Furthermore, TT125-802 is capable to interfere with transcriptional resistance mechanisms limiting targeted therapies (6) which will be explored clinically upon determination of a safe, well-tolerated, and biologically active single-agent dose. Methods: This study aims to establish the safety, tolerability, and pharmacokinetic profile of TT125-802. The maximum tolerated dose/recommended dose for expansion (MTD/RDE) of repeat daily dosing for TT125-802 monotherapy will be determined in subjects with advanced solid tumors in a sequential escalating cohorts design, (1 cycle = 21 days) using the Bayesian Logistics Regression Model (BLRM) with sentinel patients (2-day window for first patient enrolled in each cohort). Cohorts will consist of 3 to 6 subjects who will be followed over a dose-limiting toxicity (DLT) period of at least 21 days. TT125-802 will be administered orally once daily; additional schedules may be evaluated. Dose escalation is planned to follow two-fold increments. It may be adapted upon dose level revision and guided by pharmacokinetic analysis. Additional subjects (up to 6) may be enrolled in at least two monotherapy cohorts deemed safe and tolerable to optimize the recommended phase 2 dose (RP2D). Up to a total of 20 additional subjects may be enrolled. Translational/pharmacodynamic endpoints: Exploratory endpoints will provide proof-of-principle and early biomarker data for CBP/p300 inhibition. These analyses will include: 1. Single-cell gene expression evaluation of peripheral blood mononuclear cells (PBMCs) at multiple time points, 2. anagen hair bulb bulk RNAseq analysis, and 3. paired tumor biopsies will be analyzed with single-cell RNA sequencing. Together, these investigations are expected to support optimal dose determination. Additionally, circulating tumor DNA might be evaluated to define molecular responses. Outlook: The recommended phase 2 dose will be used further to explore the efficacy of TT125-802 as monotherapy. TT125-802 will be evaluated with targeted therapies (for example, KRASG12C/D, BRAF, EGFR, etc., inhibitors) to exploit the blocking of transcriptional escape mechanisms driven by CBP/p300. 1. Iyer, 2007. 2. Dutta, 2016. 3. Attar, 2017. 4. AACR2023 posters #6268. 5. AACR poster #3907. 6. AACR2023 poster #3907. Clinical trial information: 2022-500849-24-00 .

The Triterpenoid CDDO-Methyl Ester Reduces Tumor Burden, Reprograms the Immune Microenvironment, and Protects from Chemotherapy-Induced Toxicity in a Preclinical Mouse Model of Established Lung Cancer.

NRF2 activation protects epithelial cells from malignancy, but cancer cells can upregulate the pathway to promote survival. NRF2 activators including CDDO-Methyl ester (CDDO-Me) inhibit cancer in preclinical models, suggesting NRF2 activation in other cell types may promote anti-tumor activity. However, the immunomodulatory effects of NRF2 activation remain poorly understood in the context of cancer. To test CDDO-Me in a murine model of established lung cancer, tumor-bearing wildtype (WT) and Nrf2 knockout (KO) mice were treated with 50-100 mg CDDO-Me/kg diet, alone or combined with carboplatin/paclitaxel (C/P) for 8-12 weeks. CDDO-Me decreased tumor burden in an Nrf2-dependent manner. The combination of CDDO-Me plus C/P was significantly (p < 0.05) more effective than either drug alone, reducing tumor burden by 84% in WT mice. CDDO-Me reduced the histopathological grade of WT tumors, with a significantly (p < 0.05) higher proportion of low-grade tumors and a lower proportion of high-grade tumors. These changes were augmented by combination with C/P. CDDO-Me also protected WT mice from C/P-induced toxicity and improved macrophage and T cell phenotypes in WT mice, reducing the expression of CD206 and PD-L1 on macrophages, decreasing immunosuppressive FoxP3+ CD4+ T cells, and increasing activation of CD8+ T cells in a Nrf2-dependent manner.

Exploring Synergistic Interactions between Natural Compounds and Conventional Chemotherapeutic Drugs in Preclinical Models of Lung Cancer.

In the current work, the synergy between natural compounds and conventional chemotherapeutic drugs is comprehensively reviewed in light of current preclinical research findings. The prognosis for lung cancer patients is poor, with a 5-year survival rate of 18.1%. The use of natural compounds in combination with conventional chemotherapeutic drugs has gained significant attention as a potential novel approach in the treatment of lung cancer. The present work highlights the importance of finding more effective therapies to increase survival rates. Chemotherapy is a primary treatment option for lung cancer but it has limitations such as reduced effectiveness because cancer cells become resistant. Natural compounds isolated from medicinal plants have shown promising anticancer or chemopreventive properties and their synergistic effect has been observed when combined with conventional therapies. The combined use of an anti-cancer drug and a natural compound exhibits synergistic effects, enhancing overall therapeutic actions against cancer cells. In conclusion, this work provides an overview of the latest preclinical research on medicinal plants and plant-derived compounds as alternative or complementary treatment options for lung cancer chemotherapy and discusses the potential of natural compounds in treating lung cancer with minimal side effects.

Abstract LB282: Therapeutic efficacy and dosimetry for a 177-lutetium radiolabeled minibody targeting DLL3 in a preclinical model of small cell lung cancer

Abstract Small cell lung cancer (SCLC) is the most aggressive subtype of lung carcinoma with a 5-year survival rate below 7%. While the addition of anti-PD-1 antibody treatment has improved SCLC patient outcomes, nearly all patients relapse, indicating an unmet need for more efficacious therapeutics. Delta-like ligand 3 (DLL3) is an inhibitory Notch ligand that is over-expressed on the surface of SCLC tumor cells. Due to this, DLL3 has become a target of interest for SCLC treatment and several agents are in preclinical and clinical evaluation using different strategies such as antibody-drug conjugates, bispecific T cell engagers, and DLL3-targeting CAR-T. Minibodies are antibody fragments that provide optimal pharmacokinetics for the delivery of radioactive payloads. Their molecular weight of 80 kDa allows for rapid tumor uptake and faster circulation clearance than full-length antibodies. These scaffolds also present deeper tumor penetration relative to full-length antibodies, and higher target specificity and retention at the tumor site, with respect to small molecules. We hypothesized that a minibody targeting DLL3 (IAB57) would be a valid approach for radiopharmaceutical therapy (RPT) of SCLC and tested its efficacy in a preclinical model of SCLC. We conjugated the IAB57 minibody with DOTAGA and radiolabeled the protein with the β-emitter 177-Lu. Nu/J female mice were inoculated subcutaneously with the non-encapsulated lung carcinoma cell line SHP77, and the tumor size was measured 3 times per week until it reached 100-150 mm3. 24-hour biodistribution results revealed a tumor uptake of 18.8% injected dose per gram (%ID/gr). Mice were treated with 13.3 MBq and 13.6 MBq doses of 177-Lu-DOTAGA-IAB57 7 days apart to determine if there was a therapeutic effect and improved animal survival. A subgroup of mice was not treated and was considered controls. A time course biodistribution was performed to assess organs dosimetry. The dosimetry results were extrapolated to human organ exposure showing kidneys and liver uptakes of 2.2 and 4.6 Gy which is 10 times and 7 times below published exposure thresholds (23 Gy and 32 Gy respectively). Exposure at bone marrow (b.m., 0.1 Gy), spleen (1.5 Gy) and lungs (0.4 Gy) were 20 times, 27 times and 68 times below published toxicity thresholds (b.m.: 2 Gy; spleen: 40 Gy; lungs: 27 Gy). The RPT data showed a significant decrease in tumor size beginning on day 11 in the treated group compared to the control group. The decreased tumor size also coincided with a doubling in the survival rate. Overall, these results indicate that the IAB57 minibody targeting DLL3 is a promising and effective agent for RPT treatment of SCLC via β-emitting radionuclides. Citation Format: Kelley C. Atkinson, Leticia M. De Souza Cordeiro, Fang Jia, Argin Aivazian, Gareth E. Smith, Ian Wilson, Alessandro Mascioni. Therapeutic efficacy and dosimetry for a 177-lutetium radiolabeled minibody targeting DLL3 in a preclinical model of small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB282.

Abstract 4322: Inhibition of ULK and KRASG12C control tumor growth in preclinical models of lung cancer

Abstract Approximately 30% of lung cancers are driven by mutationally activated KRAS. The recent FDA approval of sotorasib, a direct pharmacological inhibitor of KRASG12C, marks a critical milestone in the treatment of this important subset of lung cancer. However, a major obstacle in treating lung cancer is resistance to current therapeutic treatments. In response to cellular stresses such as RAS pathway-targeted therapeutics, RAS-mutated cancer cells have been demonstrated to increase autophagy, an intracellular recycling pathway. However, the mechanism(s) underlying treatment-induced autophagy is not well understood. Here, we demonstrate that KRASG12C-driven lung cancer cells increase autophagy in response to treatment with sotorasib. Currently, the only therapeutics in clinical use to inhibit autophagy are lysosomal inhibitors (hydroxy)chloroquine. High concentrations of these compounds are needed to achieve modest inhibition of autophagy, suggesting that the potency of these compounds may limit clinical responses. ULK kinases are serine/threonine kinases that are necessary for the initiation of autophagy. DCC-3116 is a potent inhibitor of the ULK1/2 protein kinases, master regulators of autophagy. Treatment with sotorasib and DCC-3116 led to superior anti-tumor effects in preclinical models of lung cancer. Additionally, about 30% of lung cancer patients with KRAS mutations also have deletions or inactivating mutations in LKB1, a protein involved in the regulation of nutrient sensing and autophagy. In other KRAS-driven cancers, the LKB1-AMPK-ULK1 signaling axis is a proposed mechanism as to how autophagic flux increases following KRAS pathway inhibition. However, our preliminary data demonstrates that LKB1 is dispensable for sotorasib-induced autophagy, suggesting the mechanism(s) of autophagy induction in KRASG12C-driven lung cancer may be different from those detected in other KRAS mutated cancers. Consequently, we have generated genetically engineered mouse models (GEMMs) of KRASG12C-driven lung cancer in which LKB1 is silenced to further investigate the role of LKB1 in the autophagy response of KRASG12C-driven lung cancers to pathway-targeted blockade of oncogenic KRAS signaling. We have treated KRASG12C-driven GEMMs with sotorasib and/or DCC-3116 to test the sensitivity of lung tumors to these treatment options. Citation Format: Phaedra Ghazi, Kayla O'Toole, Sanjana Boggaram, Michael Scherzer, Madhumita Bogdan, Bryan Smith, Dan Flynn, Conan Kinsey, Martin McMahon. Inhibition of ULK and KRASG12C control tumor growth in preclinical models of lung cancer [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 4322.

Abstract 2028: The triterpenoid CDDO-Methyl ester requires Nrf2 to decrease lung tumor burden and to protect against the toxicity of chemotherapy in experimental lung cancer

Abstract The NRF2 cytoprotective pathway, a drug target for many inflammation-related diseases, regulates immune cell function. While the anti-inflammatory nature of NRF2 activation protects healthy cells from malignant transformation, cancer cells can utilize the pathway to promote resistance to anti-cancer drugs. Up to 30% of human lung adenocarcinomas acquire mutations in either NFE2L2 or its negative regulator KEAP1 which result in constitutive activation of the NRF2 pathway. However, despite our knowledge of the important immunomodulatory effects of NRF2, these effects are not well characterized in the context of cancer. With NRF2 activators now approved for clinical use, it is critical to understand the impact of these drugs in cancer. Triterpenoids including CDDO-methyl ester (CDDO-Me, also known as bardoxolone methyl) are potent pharmacological NRF2 activators with demonstrated anti-cancer activity in preclinical models. In an early-stage preclinical model of lung cancer, CDDO-Me significantly decreased tumor burden in a dose- and Nrf2-dependent manner and improved immune signatures within the tumor microenvironment. However, most human lung cancers are not diagnosed until more advanced stages. To test CDDO-Me in an established tumor intervention model, lung tumors were initiated with vinyl carbamate in A/J WT and Nrf2 knockout (KO) mice. Tumors were allowed to develop for 8 weeks post initiation, after which mice were fed either a vehicle control diet or CDDO-Me (50-100 mg/kg of diet) for an additional 8-12 weeks, alone or in combination with carboplatin and paclitaxel (C/P) at 50 mg/kg and 15 mg/kg, respectively, by IP injection every other week. CDDO-Me significantly (p &amp;lt; 0.05) decreased surface lung tumor counts 35-71% in a Nrf2-dependent manner, and C/P significantly (p &amp;lt; 0.001) reduced tumor burden 53-59% regardless of Nrf2 status. The combination of CDDO-Me + C/P reduced tumor burden in WT lungs by 84% (p &amp;lt; 0.05), more than either agent alone. Nrf2 KO mice had an approximately two-fold increase (p &amp;lt; 0.001) of surface tumors compared to WT mice in both studies, regardless of treatment. C/P reduced tumor burden similarly in Nrf2 WT and Nrf2 KO mice. Interestingly, the combination of CDDO-Me + C/P increased T cell infiltration into the lungs of WT mice, but this change was not observed in groups treated with either agent alone. Importantly, CDDO-Me did not decrease the efficacy of C/P but protected WT mice from mortality and weight loss and lowered white and red blood cell counts. These studies suggest that NRF2 activation in advanced lung cancers can still decrease tumor burden by favorably modulating the immune microenvironment and, importantly, complements the anti-tumor efficacy of conventional chemotherapy while decreasing drug toxicity. Citation Format: Jessica Ann Moerland, Karen T. Liby. The triterpenoid CDDO-Methyl ester requires Nrf2 to decrease lung tumor burden and to protect against the toxicity of chemotherapy in experimental lung cancer [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 2028.

Abstract 4093: Modeling tumor immunoediting under immune selective pressure to inform neoantigen landscape dynamics for effective cancer vaccines

Abstract Tumor specific neoantigens, encoded by somatic mutations, are recognized by T cells, inducing anti-tumor immune responses. This renders neoantigens viable targets for personalized cancer vaccines. However, the identification of immunogenic neoantigens remains suboptimal. Understanding how immune selective pressure-mediated tumor evolution and neoantigen editing contribute to emergence of immunogenic neoantigens may improve prediction accuracy. In this study, we aimed to model tumor evolution and heterogeneity under immune pressure using three preclinical models of lung cancer with common driver mutations, Kras G12D/+ and p53 -/-, namely KPA, KPC, and HKP1, subcutaneously implanted in immunocompetent C57BL/6 (B6) and immune-deficient Rag1-/- mice. Our data suggest that despite shared driver mutations identified by whole exome and RNA-seq, tumor growth in vivo varied between tumor models. KPA tumors were immunogenic, as they were controlled in B6 mice but rapidly progressed in Rag1-/- mice, suggesting immunoediting of KPA-specific neoantigens. In contrast, HKP1 was non-immunogenic, with tumors progressing regardless of immune competency. KPC showed moderate tumor control in B6 mice, which was lost in Rag1-/- mice. We then estimated the cancer cell fraction on every mutation based on phylogenetic reconstruction. Immunogenic KPA tumors had significantly lower mutation burden in B6 than in Rag1-/- mice and the fraction of cell line mutations edited in vivo was significantly higher, suggesting active immunoediting in the former. Non-immunogenic HKP1 tumors did not show significant differences in mutation burden nor fraction of mutations edited between B6 and Rag1-/- mice. The immunogenicity was reflected in the immune infiltrate levels within tumors, with KPA being highly infiltrated by activated CD4 and CD8 T cells compared to KPC. HKP1 tumors showed increased infiltration of suppressive regulatory T cells. T cell receptor (TCR) sequencing on lung tumors showed that clonal expansion is strongly associated with immunogenicity. KPA tumors showed significantly higher TCR clustering with less diversity compared to KPC and more than HKP1. Following a simple approach to study the immunogenicity of shared neoantigens to elicit cross-protective anti-tumor responses, mice were immunized with whole irradiated (IR) tumor cell lines and implanted with live tumor cells (matched and unmatched). While immunization with IR-KPA protected against corresponding tumor implant and moderately against KPC, it did not protect against HKP1, indicating lack of immunogenicity of mutations shared between KPA and HKP1. Further studies testing the anti-tumor responses and characteristics of neoantigens shared between these three related tumor cell lines will inform the conditions under which tumors may escape or regress and help improve neoantigen identifying algorithms. Citation Format: Mariam Mathew George, Jayon Lihm, Hyejin Choi, Yuval Elhanati, Stephen Martis, Marta Luksza, Benjamin Greenbaum, Jedd D. Wolchok, Taha Merghoub. Modeling tumor immunoediting under immune selective pressure to inform neoantigen landscape dynamics for effective cancer vaccines [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 4093.

Abstract 6028: Preferential tumor-to-normal tissue biodistribution and single-dose efficacy with ABD147, a DLL3-targeted engineered antibody-based radiotherapeutic, in preclinical small cell lung cancer models

Abstract Targeted radiotherapies represent an emerging treatment modality for aggressive cancers with limited treatment options, such as small cell lung cancer (SCLC). ABD147 is a Delta Ligand 3 (DLL3)-targeted antibody conjugate designed to carry and deliver cytotoxic radioactive isotopes to DLL3-expressing tumor cells. DLL3 is commonly expressed on the cell surface of neuroendocrine cancer cells, including SCLC, but has limited and predominantly intracellular expression in non-malignant tissues. The ABD147 antibody specifically binds human DLL3 with high affinity and is internalized by DLL3-expressing cancer cells. To minimize radiation exposure to normal tissue, ABD147 has been engineered to clear quickly from the blood compartment. Using indium-111 to determine ABD147 pharmacokinetics and biodistribution in mice, we demonstrate rapid blood and normal tissue clearance of 111In-ABD147, as designed, following a single intravenous dose administration. However, 111In-ABD147 retains high tumor accumulation (activity concentration of up to 30% ID/g) in xenograft mouse models of SCLC despite low DLL3 surface antigen expression on tumor cells (≤ 3000 copies). 111In-ABD147 shows a favorable tumor-to-normal tissue distribution with predominant liver clearance. Following ABD147 therapeutic radioisotope delivery of actinium-225 or lutetium-177 (225Ac-ABD147, 177Lu-ABD147), we demonstrate single-dose tumor regression and dose-dependent sustained anti-tumor efficacy, corresponding to an extension of survival out to 84 days in multiple SCLC xenograft models. In summary, ABD147 can preferentially deliver radionuclides to DLL3-expressing tumor tissue while substantially reducing the systemic radioactive exposure typical of conventional IgG radioconjugates. Following promising results in preclinical models, including potent anti-tumor activity, 225Ac-ABD147 is now progressing into clinical development. Citation Format: Iva Kulic, Etienne S. Melese, Emma Cummins, Alex Mandel, Raja Viswas, Michael Abrams, Adam Judge. Preferential tumor-to-normal tissue biodistribution and single-dose efficacy with ABD147, a DLL3-targeted engineered antibody-based radiotherapeutic, in preclinical small cell lung cancer 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 6028.

Abstract 7274: Optimization of intermittent dosing strategies of KRAS G12C inhibitors in preclinical lung cancer model

Abstract Cysteine-binding targeted drugs AMG-510 and MRTX-849 provide a new therapeutic approach for advanced KRASG12C mutant cancers. However, clinical response has been limited. Responders eventually develop adaptive resistance by gaining additional MAPK pathway mutations, resulting in limited therapeutic benefit. High-dose pulsatile treatment with MAPK pathway inhibitors has been proposed as an alternative strategy to alleviate adaptive resistance while maintaining tumor control. The sensitivity of tumor cells to pan-inhibitors of the MAPK pathway, crucial for proliferation, creates a therapeutic opportunity window for immune cells to restore their function during an intermittent regimen. Congruently, we have previously shown that intermittent pan-MAPK pathway inhibitor treatment delays drug resistance, supports T cell activation, and enhances tumor delay when combined with immunotherapy. In this study, we investigated the effects of continuous and pulsatile KRASG12C inhibition on tumor and immune cells in order to design combinatorial strategies with immune-modulating agents that overcome drug resistance. Our data suggest that a weekly single high-dose regimen of AMG-510 is less effective at achieving tumor control in preclinical mouse models of KRAS mutant lung cancer compared to daily treatments. However, supplementing this pulsatile regimen with lower maintenance doses markedly slows the growth of LLC KRASG12C lung cancer. Flow cytometry analysis revealed that high-dose pulse regimen enhances T cell activation, evidenced by increased expression of TCF-1, Ki67, PD-1, and GITR, along with lower expression of co-inhibitory molecules Lag-3 and Tim-3, 3 days after treatment. In vitro, AMG-510 also improves the antigen presentation of OVA-expressing LLC-KML lung cancer cells via MHC class I and, to a lesser extent, MHC class II. Furthermore, we found that while combinatorial therapy with PD-1 blockade alone does not significantly impact tumor control, the combination with CTLA-4 blockade shows efficacy across pulsatile and continuous AMG-510 dosing cohorts. Overall, our findings suggest that the utilization of intermittent dosing regimens for selective KRASG12C inhibitors is a promising approach for improving clinical responses in lung cancers with KRAS mutations. Future experiments will aim to delineate MAPK pathway behavior in vivo and in vitro under pulsatile and continuous treatment, assess immunogenicity, and further characterize immune changes in the different treatment regimens, with the goal of designing more efficient cancer therapies utilizing selective KRAS inhibitors. Citation Format: Valeria Estrada Navarro, Vincent Panneton, Lauren Dong, Hyejin Choi, Divya Venkatesh, Rachana Maniyar, Isabell Schulze, Jedd D. Wolchok, Taha Merghoub. Optimization of intermittent dosing strategies of KRAS G12C inhibitors in preclinical lung cancer model [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 7274.

Abstract 1926: MRAS the forgotten member of the GTPase superfamily plays a role in KRASG12Ci resistance

Abstract KRASG12C inhibitors have achieved impressive results in the clinic. However, intrinsic or acquired resistance to therapy invariably develops leading to disease progression in most treated patients. Emerging pre-clinical and clinical evidence points to multiple mechanisms being responsible for resistance to KRASG12C inhibitors, including receptor tyrosine kinase (RTK) activation, KRASG12C amplification, activation of alternative signaling pathways including PI3K, mTOR, YAP/TAZ, acquisition of KRAS mutations that would preclude compound binding (e.g. R68S, Y96C/D, H95D/Q/R), conversion of the G12C codon mutation, and additional activating KRAS mutations (G13D, Q61H). In the clinic, many of the described mutations were detected at low frequency, some patients displayed multiple mutations and in 40% of patients no potential driving mutations were identified. It is therefore likely that other non-genetic alterations are also involved in resistance to KRASG12Ci monotherapy. Here, we used preclinical models of KRASG12C non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) to study intrinsic and acquired resistance to KRASG12C inhibitors. Increased expression of the RAS superfamily gene MRAS was observed in most KRASG12C-naïve tumor cells upon treatment with a KRASG12C inhibitors. In line with this, we observed an increase of MRAS-GTP levels in cells treated with KRASG12Ci in vitro. Interestingly, the increase in active MRAS did not lead to concomitant upregulation of MAPK signaling. Long term treatment with adagrasib was used for generating in vitro and in vivo KRASG12C models with acquired resistance to KRASG12Ci. A strong increase in MRAS expression was observed under these conditions, that surpassed the levels seen with short term treatment in naïve models. This data suggests that activation of MRAS-SHOC2-PP1C complex may play a role in compensating for the KRASG12C-driven signaling in both the intrinsic and acquired resistance setting. Knockdown of SHOC2 to baseline levels resulted in re-sensitization to KRASG12Ci monotherapy and to the effects of combinations in adagrasib-resistant NCI-H358 NSCLC cells. Pathway suppression was deepened by combining adagrasib with either a SOS1i (e.g. BI-3406) or SHP2i (e.g. TNO155) resulting in enhanced anti-tumor effects observed in the KRASG12Ci-resistant models. Our findings underscore the role of MRAS in acquired resistance in KRASG12Ci and the potential to overcome this with vertical pathway combinations, such as SOS1i or SHP2i. Citation Format: Venu Thatikonda, Kaja Kostyrko, Sabine Jurado, Simone Lieb, Melanie Hinkel, Donat Alpar, Oliver Bergner, Astrid Jeschko, Mark Pearson, Marco H. Hofmann. MRAS the forgotten member of the GTPase superfamily plays a role in KRASG12Ci resistance [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 1926.

Abstract 3864: Role of NK/TAM cross-talk on T-CD8+ recruitment and efficacy of chemoimmunotherapy and MEKi combination in "cold" tumors

Abstract In patients with non-small cell lung cancer (NSCLC), double platinum-based chemotherapy (cisplatin or carboplatin and pemetrexed) combined with the anti-PD-1 antibody has shown significant clinical benefit and has become the standard of care. In the context of so-called "cold" tumors, the immunogenic capacities of chemotherapies increase danger signals (type I IFNs, CXCL9/10) and favor both infiltration of NK/T-CD8+ cells and response to anti-PD-1. Despite the therapeutic progress represented by this new combination, some patients have limited benefit from chemo-immunotherapy, suggesting that in these patients, the immunogenic capacities of chemotherapy are limited. Recently, we were able to show that KRAS oncogene signaling restricts the ability of the cisplatin/pemetrexed doublet to induce the chemokine CXCL10, lymphocyte recruitment and sensitize to PD-L1 blockade. Thus, the addition of a MEK inhibitor (MEKi) to the chemo-immunotherapy combination restores an immunogenic signal through CXCL10, enabling T-CD8+ to infiltrate the tumor more extensively, making it more sensitive to immunotherapy. Here, we unravel the essential role of NK cells in the immunological and antitumoral effect of chemo-immunotherapy plus MEKi combination in the LLC1 preclinical lung cancer model. We showed that chemo/MEKi combination favors NK cell recruitment and activation in tumor bed through both CXCL10 and NKG2D-ligand (Rae1, Mult1). Then, IFNγ-producing NK cells trigger tumor associated macrophage switch from M2 toward M1 phenotype and amplify T-CD8+ cells recruitment through CXCL9 production by macrophages. Thus, NK cell depletion, CXCR3, CXCL9 or NKG2D-neutralization restrained chemo/MEKi therapeutic efficacy. However, IFNγ also triggers NKG2A-ligand expression (Qa-1b, HLA-E in human) which restrained NK cell activation and CD8+ T cell recruitment. Thus reducing the NKG2A pathway, by using Qa-1b-/- LLC1 cells, enhances chemo-immunotherapy/MEKi anti-tumor efficacy. Similar results were obtained in preclinical “cold” CT26 colon cancer model treated by chemo-immunotherapy. Our results underline a new role for NK cell activation to trigger TAM2/TAM1 switch, CXCL9 expression and amplify CD8 T cell recruitment in “cold” tumor. In a context of resistance to chemo-immunotherapy, MEKi or ICI targeting NK cells could be an interesting way to amplify the anti-tumor immune response by modulating both TAMs biology and the recruitment of CD8+ T cells. Citation Format: Lisa Nuttin, Charlène Latour, Solène Revy, Romain Aucagne, Guilhem Lalle, François Ghiringhelli, Emeric Limagne. Role of NK/TAM cross-talk on T-CD8+ recruitment and efficacy of chemoimmunotherapy and MEKi combination in "cold" tumors [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 3864.

A novel therapeutic outlook: Classification, applications and challenges of inhalable micron/nanoparticle drug delivery systems in lung cancer (Review).

Lung cancer represents a marked global public health concern. Despite existing treatment modalities, the average 5‑year survival rate for patients with patients with lung cancer is only ~20%. As there are numerous adverse effects of systemic administration routes, there is an urgent need to develop a novel therapeutic strategy tailored specifically for patients with lung cancer. Non‑invasive aerosol inhalation, as a route of drug administration, holds unique advantages in the context of respiratory diseases. Nanoscale materials have extensive applications in the field of biomedical research in recent years. The present study provides a comprehensive review of the classification, applications summarized according to existing clinical treatment modalities for lung cancer and challenges associated with inhalable micron/nanoparticle drug delivery systems (DDSs) in lung cancer. Achieving localized treatment of lung cancer preclinical models through inhalation is deemed feasible. However, further research is required to substantiate the efficacy and long‑term safety of inhalable micron/nanoparticle DDSs in the clinical management of lung cancer.

Abstract C145: ANS014004, a novel small-molecule type II c-Met inhibitor effectively overcomes clinical-resistance MET mutations and exhibits antitumor activity in preclinical models of MET-amplified non-small cell lung cancer (NSCLC) and gastric cancer

Abstract Mesenchymal epithelial transition (MET) proto-oncogene receptor tyrosine kinase (RTK) is a cell surface receptor selective for hepatocyte growth factor (HGF), and is involved in embryogenesis regulation, wound healing, organ regeneration, angiogenesis, and immunomodulation. Aberrant MET oncogenic alterations include: MET exon 14 skipping (MET∆ex14) mutations; activating mutations in the kinase domain; MET gene amplification; MET fusions; and MET protein overexpression. These oncogenic alterations occur in a wide range of human solid cancers. Small-molecule type I c-Met inhibitors bind to the active (Asp-Phe-Gly “DFG-in” state) of c-Met within the adenosine triphosphate (ATP) binding pocket via the Y1230 residue, resulting in down-regulation of multiple pro-oncogenic downstream factors. Presently, type I c-Met inhibitors such as Capmatinib are used as monotherapies in patients with locally advanced or metastatic NSCLC with MET∆ex14 mutations. However, development of post-treatment resistance to type I c-Met inhibitors occurs clinically, including through acquired mutations in codons D1228 and Y1230. No drugs have been approved globally for MET alteration indications other than MET∆ex14 mutations. Next generation MET inhibitors are thus needed to treat patients harboring various MET oncogenic alterations beyond MET∆ex14, including post-treatment acquired mutations. ANS014004 is a newly developed small-molecule type II inhibitor of c-Met, binding to the inactive state of c-Met (“DFG-out”) in the ATP pocket. ANS014004 showed greater kinase inhibition activity against c-Met mutant kinases Y1230H and D1228A in vitro (IC50’s = 2.596 and 2.971 nM, respectively), when compared with Capmatinib, Cabozantinib, and Merestinib (IC50 values = &amp;gt;5000, ~10, and ~5 nM respectively). Further, ANS014004 showed a stronger anti-proliferative effect in MET mutant Ba/F3 cells TPR-Met D1228A and TPR-Met-Y1230H in vitro (IC50’s = 49.34 nM and 30.32 nM, respectively), when compared with Capmatinib (IC50 values&amp;gt;10000nM) and Merestinib (IC50 values: 37~100 nM). ANS014004 also showed potent antitumor effects in vitro in the human cancer tumor cell lines harboring various pathogenetic MET alterations: Hs-746T (gastric); MKN-45 (gastric); EBC-1 (NSCLC); NCI-H1993 (NSCLC); with IC50 ranging from 6.38~62.32 nM. In several subcutaneous xenograft tumor model studies using these same cell lines implanted in BALB/c nude mice, orally administered ANS014004 produced significant dose-dependent tumor growth inhibition, and the corresponding exposures of ANS014004 in plasma, tumor and brain samples increased with increasing dose. ANS0104001 was also observed to induce tumor regression in a MET-amplified intracranial xenograft model. Overall, the non-clinical studies of ANS014004 demonstrated it is a potent, orally-bioavailable type II c-Met inhibitor with activity against various pathogenetic MET alterations and with favorable absorption, distribution, pharmacokinetic, efficacy, and tolerability profiles in vivo. The molecule will enter a Phase 1 clinical study in the US soon. Citation Format: Gong Li, Hepeng Shi, Peilong Zhang, Xiangqiu Li, Wenli Lan, Linna Li, David Chung, Kevin Schaab. ANS014004, a novel small-molecule type II c-Met inhibitor effectively overcomes clinical-resistance MET mutations and exhibits antitumor activity in preclinical models of MET-amplified non-small cell lung cancer (NSCLC) and gastric cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C145.

Abstract A064: Establishing the cellular and molecular impacts of the dual BRM/BRG1 inhibitor FHD-286 on pre-clinical models of non-small cell lung cancer (NSCLC)

Abstract The BRG/BRM-associated factor (BAF) complex plays critical roles in chromatin regulation. Within this complex, the two mutually exclusive ATPases BRM and BRG1 (SMARCA2 and SMARCA4, respectively) drive chromatin remodeling activity. Genetic alterations in the SMARCA4 gene, encoding BRG1, are found in approximately 10% of non-small cell lung cancer (NSCLC) patients, leaving this subset of BRG1-deficient tumors highly susceptible to BRM inhibition. In addition, BRG1 has oncogenic activity in NSCLC, rationalizing the use of a dual BRM/BRG1 ATPase inhibitor, such as the highly potent clinical stage compound FHD-286, in NSCLC patients, regardless of SMARCA4 status. Here, we demonstrate that a panel of NSCLC cell lines respond to dual BAF ATPase inhibition in both in vitro and in vivo settings, regardless of SMARCA4 mutation status. Interestingly, dual BRM/BRG1 inhibition in cell lines reduces chromatin accessibility at motifs normally bound by AP-1 transcription factors, which play tumorigenic roles in NSCLC. We also find that expression of the stemness-associated glycoprotein CD44 is decreased by FHD-286, suggesting that dual BRM/BRG1 inhibition impacts the differentiation state of NSCLC. Moreover, transcriptional analyses of NSCLC xenograft models reveal that a basal cell gene expression signature, which is associated with a less differentiated cell state, is downregulated by FHD-286 treatment. Finally, genome-wide CRISPR knockout screening with FHD-286 in 2 NSCLC lines further elucidates mechanisms of action and molecular vulnerabilities induced by dual BAF ATPase inhibition. Collectively, these results indicate a path forward for the development of FHD-286 for the treatment of NSCLC patients. Citation Format: Molly M. Wilson, Ammar Adam, Victoria Amaral, Oliver Mikse, GiNell Elliott, David L. Lahr, Ashley K. Gartin, Jessica Wan, Liv Johannessen, Kana Ichikawa, Katharine Feldman, Jessica Piel, Gabriel J. Sandoval, Richard C. Centore, Steven F. Bellon, Martin Hentemann. Establishing the cellular and molecular impacts of the dual BRM/BRG1 inhibitor FHD-286 on pre-clinical models of non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A064.

Abstract B025: The next generation farnesyltransferase inhibitor, KO-2806, blocks oncogenic signaling at multiple nodes to enhance the antitumor efficacy of KRASG12C inhibitor adagrasib in KRASG12C non-small cell lung carcinoma

Abstract Emerging clinical and preclinical data have shown that responses to KRASG12C inhibition are limited by the activation of compensatory signaling proteins, including receptor tyrosine kinases (RTKs) and mTOR. Combination therapeutic strategies co-targeting these nodes are needed to fully realize the potential of breakthrough KRASG12C-selective inhibitors. We propose that, given its multipronged mechanism of action, KO-2806, a next-generation farnesyltransferase inhibitor (FTI) with increased potency and improved pharmacokinetic properties relative to earlier FTI candidates that is poised to enter a first-in-human clinical trial, is a uniquely suited combination partner for KRASG12C inhibitors. Here, we evaluate the therapeutic potential of combined KO-2806 and adagrasib in preclinical models of KRASG12C non-small cell lung cancer (NSCLC). Our previous work indicated that FTIs amplify the antitumor effects of PI3Kα inhibition by blocking compensatory mTOR signaling. As activation of compensatory signaling is a well-described bypass mechanism to escape KRAS inhibition, we asked whether KO-2806 could improve the in vivo efficacy of adagrasib. Combination of KO-2806 with adagrasib led to markedly enhanced antitumor effects in KRASG12C-mutant NSCLC cell line- and patient-derived xenograft models compared to adagrasib alone. Tumor regression in the combination group corresponded to increased apoptosis, as evidenced by higher cleaved caspase 3 staining in combination-treated tumors compared to single agent groups. Intriguingly, adagrasib induced expression of the RTK HER3, a potential driver of bypass signaling, while HER3 expression in combination-treated tumors was lower than in vehicle-treated tumors. To further interrogate the mechanistic basis of the observed in vivo synergy, we cultured KRASG12C-mutant cell lines as 3D tumor spheroids and exposed them to KO-2806 and/or adagrasib. Consistent with the xenograft tumor data, spheroids exposed to the combination expressed lower levels of the upstream receptor HER3 (total and phosphorylated forms) and higher levels of apoptotic markers cleaved PARP and cleaved caspase 3. Concurrently, activity of the downstream effectors ERK and mTOR was reduced. Co-exposure to KO-2806 and adagrasib potently inhibited phosphorylation of ERK and its substrate p90 RSK as well as phosphorylation of mTOR substrates p70 S6K, 4EBP1, and S6. The mTOR signaling reduction paralleled defarnesylation of the farnesylation-dependent mTOR activator RHEB, so we depleted RHEB expression in spheroids and assayed their growth. Genetic depletion of RHEB phenocopied the antiproliferative effects of KO-2806 in combination with adagrasib, implicating RHEB as an important farnesylated target in KRASG12C NSCLC. These preclinical results suggest that KO-2806 is an effective combination partner for KRASG12C inhibitors by simultaneously targeting an upstream activator (HER3) and a downstream effector (RHEB/mTOR) of KRAS, leading to improved antitumor activity in KRASG12C-mutant NSCLC models. Citation Format: Hetika V Patel, Alison Smith, Stacia Chan, Linda Kessler, Francis Burrows, Shivani Malik. The next generation farnesyltransferase inhibitor, KO-2806, blocks oncogenic signaling at multiple nodes to enhance the antitumor efficacy of KRASG12C inhibitor adagrasib in KRASG12C non-small cell lung carcinoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B025.

Extracellular Vesicles As Mediators of Resistance to EGFR-Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer Preclinical Models

Extracellular Vesicles As Mediators of Resistance to EGFR-Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer Preclinical Models