Resistant NSCLC Research Articles

275 (PB263): Osimertinib resistant NSCLC Patient derived xenograft model mimic clinical response status of multiple TKI treatments in preclinical study

275 (PB263): Osimertinib resistant NSCLC Patient derived xenograft model mimic clinical response status of multiple TKI treatments in preclinical study

P2.11A.21 CCL4 Attenuated the Efficacy of Immunotherapy via Regulating the Phenotype and Function of Treg in EGFR-TKI Resistant NSCLC

P2.11A.21 CCL4 Attenuated the Efficacy of Immunotherapy via Regulating the Phenotype and Function of Treg in EGFR-TKI Resistant NSCLC

EP.02F.01 Berberine and Osimertinib Inhibit Progression of EGFR-TKI Primary and Acquired Resistant NSCLC Cells by a Multimodal Intervention

EP.02F.01 Berberine and Osimertinib Inhibit Progression of EGFR-TKI Primary and Acquired Resistant NSCLC Cells by a Multimodal Intervention

202P eIF4E inhibition exhibits anti-tumor activity and re-sensitizes acquired resistant KRAS G12C NSCLC to KRAS inhibitors

202P eIF4E inhibition exhibits anti-tumor activity and re-sensitizes acquired resistant KRAS G12C NSCLC to KRAS inhibitors

Efficacy, safety, and PK/PD of LVGN6051, 4-1BB agonistic antibody, with pembrolizumab in a phase Ib dose expansion in resistant NSCLC, melanoma, and GI malignancy.

Efficacy, safety, and PK/PD of LVGN6051, 4-1BB agonistic antibody, with pembrolizumab in a phase Ib dose expansion in resistant NSCLC, melanoma, and GI malignancy.

Tislelizumab combined with nab-paclitaxel single-agent chemotherapy plus bevacizumab for patients with EGFR-TKIs-resistant advanced NSCLC with ECOG PS 0-2.

e20138 Background: Treatment options are limited for EGFR-TKIs-resistant advanced NSCLC. A retrospective study from our center showed that ICIs plus platinum-free, single-agent chemotherapy provided progression-free survival, overall response rate benefit, and a low rate of severe AEs in such pts. Meanwhile,there were many NSCLC patients after treatment failure with EGFR-TKIs who ECOG performance status was 2 ,they were excluded from existing prospective studies. This study was designed to further explore the efficacy and safety of Tis plus nab- paclitaxel and Beva foradvancedNSCLCpts with ECOG ps 0-2 failed to EGFR-TKIs. Methods: This is a single-arm, phase II study (NCT04310943). Pts with EGFR mutations who had failed to prior EGFR-TKIs accepted Tis (200mg, d1) ,nab-paclitaxel (100mg/m2, d1,8,15) and Beva (15mg/kg, d1) Q3W for up to 4 cycles, followed by Tis plus Beva (7.5mg/kg) maintenance therapy. Primary endpoints are 6m-PFS% and safety, secondary endpoints include ORR and 1-year OS rate. The planned sample size was 24 with unacceptable control of 25%, an expected value of 55%, a one-sided α of 0.05, and a power of 80%, Simon's two-stage design. Results: The median age was 57 (range: 30-70). Thirteen pts (54.2%) harbored EGFR exon 19del and 9 pts (37.5%) had exon 21 L858R at the initial diagnosis. There were 9 pts (37.5%) with ECOG ps 2 and18 pts (75%) with clinical stage IVB. Twelve pts (50%) had stable brain metastases. Fifteen pts (63.6%) progressed on both 1st/2nd and 3rd EGFR-TKIs. As of Dec30, 2023, The median follow-up time was 22.2 m (95%CI 0-51.1). Among the 21pts in the efficacy analysis set, the median PFS was 6.3 m(95%CI 5.5-7.1), the 6m-PFS % was 61.6%, the 6m-PFS% of pts with ECOG ps 2 was18.1%. The ORR was 61.9%, the median DOR was 4.4 m (95%CI 2.1-6.7), DCR was 100.0%. The median OS was 15.4 (95%CI 10.1-20.7) and 1y-OS% was 59.7%. The safety was manageable: the incidence of ≥grade 3 TRAE was 25%. Conclusions: Tislelizumab combined with nab-paclitaxel plus bevacizumab is effective with a manageable safety profile for EGFR-TKIs resistant NSCLC patients with ECOG ps 0-2. Clinical trial information: NCT04310943 . [Table: see text]

YF550-C1, an E3 ligase inhibitor of CBL-B, to demonstrate T cell and NK cell activation and anti-tumor activities in syngeneic and PDX tumor model.

e14570 Background: Casitas B-lineage lymphoma b (CBL-B) is one of ligase in E3 ubiquitin family, which mainly expressed in matured hematopoietic cells, including T and NK cells. Study showed that CBL-B deficiency upregulated interleukin-2 and interferon-gamma secretion during anti-CD3 and anti-CD28 stimulated TCR activation, even without co-stimulator anti-CD28[3]. Except T cells, CBL-B plays important role in NK cells as well. CBL-B was upregulated during NK cell activation. While downregulation of CBL-B enhanced the cytotoxicity of primary human NK cells against hematological cancer cell lines. In vivo studies proved that CBL-B deficiency protected mice from tumor growth by inducing antitumor immunity. Thus, CBL-B shows a promising target for cancer therapy. Methods: We developed a small molecule YF550-C1 that targeted CBL-B, and evaluated the activation on T cell and NK cell function, and the therapeutical effect on syngeneic tumor models. The T cell activation was indicated by levels of IL-2 and IFN-γ from CBL-B knockout or WT CD8+ T cells since stimulated with anti-CD3 or anti-CD3/28 for 48 hours. The resistance of PGE2-induced immunosuppressive was evaluated by measuring IL-2 and IFN-γ since human T cells treated with PGE2 and followed by series diluted YF550-C1 or comparable inhibitor cpd23. OVA specific antigen stimulated CD8+ T activation assay was conducted by coculture OT-1 CD8+ T cells and WT DC cells with 50:1 for 72 hours in the present of 5ug/ml OVA peptide and series diluted YF550-C1. The NK cell cytotoxicity was evaluated by co-culture human NK cells and K562-luc cells with 1.25:1 ratio in the present of 1000nM or 333nM YF550-C1, which indicated by luminance. Syngeneic mouse model that inoculated with different types of murine cancer cell lines was used to evaluate tumor growth. Results: CBL-B deficiency suppressed tumor growth in mouse tumor models and enhanced cytokines release in T cells upon TCR engagement. CBL-B inhibitor, YF550-C1, alleviated PGE2-mediated immunosuppression of human T cell activation. CBL-B inhibitor, YF550-C1, enhanced OVA-specific antigen stimulated CD8+ T cell activation. CBL-B inhibitor, YF550-C1, enhanced cytotoxicity of human NK cell against K562-luc cells. CBL-B inhibitor, YF550-C1, or in combinate with anti-PD-L1 suppressed tumor growth in syngeneic tumor models. Single-agent of CBL-B inhibitor YF550-C1 treatment was sufficient to suppress PD1/PD-L1 resistant NSCLC patient-derived tumor growth. Conclusions: These studies provided insight into the activity of the inhibitor of CBL-B, demonstrating that YF550-C1 displays excellently T cell activation, T cell immunosuppression alleviation, NK cell activation and antitumor activity in multiple preclinical tumor models. Our data showed that YF550-C1 is a promising candidate for cancer treatment as monotherapy or in combination with PD-L1 blockade.

Tanshinone IIA acts as a regulator of lipogenesis to overcome osimertinib acquired resistance in lung cancer

Osimertinib is a novel epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), acting as the first-line medicine for advanced EGFR-mutated NSCLC. Recently, the acquired resistance to osimertinib brings great challenges to the advanced treatment. Therefore, it is in urgent need to find effective strategy to overcome osimertinib acquired resistance. Here, we demonstrated that SREBP pathway-driven lipogenesis was a key mediator to promote osimertinib acquired resistance, and firstly found Tanshinone IIA (Tan IIA), a natural pharmacologically active constituent isolated from Salvia miltiorrhiza, could overcome osimertinib-acquired resistance in vitro and in vivo via inhibiting SREBP pathway-mediated lipid lipogenesis by using LC-MS based cellular lipidomics analysis, quantitative real-time PCR (qRT-PCR) analysis, western blotting analysis, flow cytometry, small interfering RNAs transfection, and membrane fluidity assay et al. The results showed that SREBP1/2-driven lipogenesis was highly activated in osimertinib acquired resistant NSCLC cells, while knockdown or inhibition of SREBP1/2 could restore the sensitivity of NSCLC to osimertinib via altered the proportion of saturated phospholipids and unsaturated phospholipids in osimertinib acquired-resistant cells. Furthermore, Tanshinone IIA (Tan IIA) could reverse the acquired resistance to osimertinib in lung cancer. Mechanically, Tan IIA inhibited SREBP signaling mediated lipogenesis, changed the profiles of saturated phospholipids and unsaturated phospholipids, and thus promoted osimertinib acquired resistant cancer cells to be attacked by oxidative stress-induced damage and reduce the cell membrane fluidity. The reversal effect of Tan IIA on osimertinib acquired resistant NSCLC cells was also confirmed in vivo, which is helpful for the development of strategies to reverse osimertinib acquired resistance.

Abstract LB005: Identification of novel targets for MYC-driven hepatocellular carcinoma via transomics

Abstract Hepatocellular carcinoma (HCC) is an aggressive tumor, and treatment options for patients with unresectable HCC are limited to targeted therapies and immunotherapy. The activation and dysregulation of MYC have been implicated in multiple cancers, including HCC, where approximately 30% of human HCC samples show MYC gene amplification. However, it is challenging to target MYC directly. Therefore, we applied a novel approach to circumvent targeting MYC directly by leveraging Pepper’s proprietary transomic analysis platform, COMPASS, to identify novel targets that are predicted to mimic the effect of turning MYC off. Specifically, COMPASS unlocks functional drivers of disease to identify novel drug targets. To study the role of MYC in tumor biology, we utilize an HCC cell line with tunable MYC expression. We generate genomic, transcriptomic, proteomic, and phosphoproteomic data from samples with MYC-on and MYC-off and compare via COMPASS to identify novel targets that mimic turning MYC off. The MYC-conditional HCC cell line (EC4) allows the regulation of MYC expression via the tetracycline regulatory (Tet-Off) system. Four omic datasets were collected from each sample: genomics (next-generation sequencing, NGS), transcriptomics (NGS), proteomics (mass spectrometry), and phosphoproteomics (mass spectrometry). We employed the COMPASS target prioritization algorithm to identify and rank novel targets that mimic turning MYC off. Targets were then filtered to select those with an available pharmacological tool compound (PTC). The PTCs were used to evaluate the targets in the Huh-7 xenograft model of HCC. All targets were kinases or related to kinase activity and pathways. All PTCs inhibited tumor growth from 18.1-78.3%. One multi-tyrosine kinase inhibitor resulted in maximum tumor growth inhibition, resulting in stasis of tumor growth and increased survival compared with control vehicle-treated mice. We have previously shown how the COMPASS transomics analysis approach can identify novel drug targets for drug resistant EGFRm NSCLC. The data presented here on MYC-driven HCC further validates this approach for novel target identification. Ongoing work will investigate novel targets using gene silencing, as PTCs were unavailable for many of these novel high-ranked targets identified in this study. Further validation studies are ongoing against other difficult-to-treat MYC-driven cancers to identify novel clinical targets and drug candidates to circumvent the MYC pathway. Citation Format: Simon P. Fricker, Christopher J. Nicholson, Samuel J. Roth, Arudhir Singh, Caitlin Brown, Jon Hu, Petronela Buiga, Vishnu P. Kanakaveti, Anja Deutzmann, Dean Felsher, Samantha D. Strasser. Identification of novel targets for MYC-driven hepatocellular carcinoma via transomics [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 LB005.

Abstract 1420: Mechanism of NPRL2 gene therapy induced antitumor immunity in KRAS/STK11mt aPD1 resistant metastatic NSCLC

Abstract NPRL2/TUSC4 is a tumor suppressor gene whose expression is reduced in many cancers including NSCLC. Restoration of NPRL2 induces cell cycle arrest and apoptosis. We investigated the antitumor immune responses to NPRL2 gene therapy in aPD1 resistant KRAS/STK11mt NSCLC in a humanized mouse model. Humanized mice were generated by transplanting human cord blood-derived CD34 stem cells into NSG mice. Mice harboring > 25% human CD45 cells were considered humanized. Lung metastases were developed in humanized mice by injecting KRAS/STK11mt/aPD1R A549 cells, which were treated with i.v. injection of NPRL2 nanoparticles (DOTAP-NPRL2) with or without pembrolizumab (aPD1). NPRL2 treatment reduced lung metastases, whereas pembrolizumab was ineffective. The antitumor effect was greater in humanized than non-humanized mice suggesting the role of immune cells. The antitumor effect was associated with increased infiltration of human cytotoxic immune cells and decreased numbers of Treg in tumors. NPRL2+ pembrolizumab was not synergistic in this resistant model but was synergistic in KRASwt/aPD1S H1299 tumors. Cytotoxic immune cells in tumors were associated with the antitumor effect. Consistent with A549, NPRL2 showed a significantly strong antitumor effect on other KRASmt/aPD1R syngeneic LLC2 tumors whereas aPD1 was not effective. The antitumor effect of NPRL2 was correlated with HLA-DR+ DC, CD11c DC, TILs and NK cells in TME. The antitumor effect of NPRL2 was abolished upon in-vivo depletion of CD4, CD8 T, and MΦ in the LLC2 tumor model. However, no effect was found on in-vivo depletion of NK cells. Nanostring analysis on lung metastasis resulted in a distinct pattern of human gene expression by NPRL2. T cell functional genes, including IFNγ, CD8b, CD7, TNFSF18, ITGA1, GATA3 and TBX21 were significantly increased. Conversely, the negative regulatory genes, including FOXP3, TGFB1, TGFB2, and IL-10RA were inhibited. NPRL2 also downregulated T cell co-inhibitory molecules, including CTLA4, ICOS, LAG3, PDCD1, CD274, IDO1, PDCD1LG2, CD47, and KLRB1. Stably expressing NPRL2 clones were established, and tumors in humanized mice with these clones exhibited significantly slower growth compared to controls. TME analysis showed an upregulation of human CD45, CD3, CD8 T, HLA-DR+ DC and a downregulation of Tregs, CD3+PD1+T, MDSC, and CD163+ TAM in tumors expressing NPRL2. The stable cells showed a substantial increase in both colony formation inhibition and apoptosis. Stable clones showed heightened sensitivity to carboplatin in colony formation, apoptosis, and PARP cleavage assays. Stable expression of NPRL2 resulted in the downregulation of both AKT-mTOR and MAPK pathways by inhibition of pAKT, pmTOR, pPRAS40, p4E-BP1, pS6, and pERK1/2. Taken together, NPRL2 gene therapy induces antitumor activity on KRAS/STK11mt/aPD1R tumors through DC-mediated antigen presentation and cytotoxic immune cell activation Citation Format: Ismail M. Meraz, Mourad Majidi, Renduo Song, Feng Meng, Lihui Gao, Qi Wang, Jing Wang, Elizabeth Shpall, Jack A. Roth. Mechanism of NPRL2 gene therapy induced antitumor immunity in KRAS/STK11mt aPD1 resistant metastatic NSCLC [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 1420.

Abstract 1939: NT219, a dual inhibitor of IRS1/2 and STAT3, suppresses cancer stem cell mediated resistance to KRASG12C and KRASG12D inhibitors in solid tumors

Abstract Background NT219 is a novel small molecule, a dual inhibitor which uniquely triggers the degradation of Insulin Receptor Substrates 1/2 (IRS) and the dephosphorylation and suppression of STAT3, two major oncogenic targets that play a key role in drug resistance. Mutated KRAS (mKRAS) has long been referred to as undruggable until recently when KRASG12C inhibitors were approved. While KRASG12C is the most common oncogenic driver in NCSLC, KRASG12D is found in 42% of pancreatic tumors. We present NT219 suppressive effect on mKRASi resistant and sensitive cells of both PDAC and NSCLC, as well as on cancer stem cells (CSC) known to contribute to disease recurrence. Method The inhibitory effects of NT219 as a monotherapy or in combination with either KRASG12C inhibitors (sotorasib/adagrasib) or KRASG12D inhibitor (MTRX1133) were tested in 2D cell growth and colony formation assays using mKRAS inhibitor sensitive and resistant cancer cell lines. The effect of NT219 and mKRASi on cancer stem cells was assessed using 3D spheroid assay evaluating spheroid size (microscopic measurements), cell viability (CellTiterGlo) and stemness marker expression (FACS analysis). Results NT219 in combination with either sotorasib or MTRX1133 suppressed established spheroids of NSCLC(KRASG12C) and PDAC(KRASG12D) respectively, in terms of size, disintegration and viability. In NSCLC H358, spheroid satellites appeared following treatment with sotorasib, while the combination with NT219 suppressed it. CSC marker ALDH increased 7-fold in NSCLC spheroids as compared to 2D grown cells, while NT219 and sotorasib suppressed it. The expression of SOX2 stemness marker was reduced by NT219 alone (5 fold), unexpectedly induced by sotorasib (4 fold) and suppressed by NT219+sotorasib (15 fold vs sotorasib alone). In addition, significant induction of STAT3, was observed following sotorasib treatment and completely reversed by the addition of NT219. We also demonstrate that NT219 induces growth inhibition in both KRASiG12C resistant PDAC and NSCLC, and KRASiG12D resistant PDAC cells. NT219 exhibited synergistic effects with adagrasib and MTRX1133, in suppressing the proliferation of KRASG12C PDAC and NSCLC cells and KRASG12D PDAC cells, respectively. This combination showed a synergistic effect in xenograft model. Conclusion We first showed the effect of NT219 in suppressing cancer stem cells, known to promote resistance and tumor recurrence. Synergistic effect of NT219 and mKRAS inhibitors, G12Cand G12D, in NSCLC and PDAC respectively, was demonstrated. Initial results suggest involvement of NT219 target proteins in resistance to mKRASG12C/D inhibitors. Treatment with sotorasib induced enhancement in stemness potential of mKRASG12C NSCLC, which NT219 efficiently suppressed, suggesting a novel therapy for this unmet need and a novel mechanism to combat resistance to mKRAS inhibitors Citation Format: Hadas Reuveni, Mohammed Najeeb Al-Hallak, Sarah Motorwala, Eliza Beal, Steve Kim, Rafic Beydoun, Gergory Dyson, Bassel El-Rayes, Herbert Chen, Philip A. Philip, Anthony F. Shields, Boris Pasche, Katy Sigalov, Hava Ben-David, Daphna Miron, Asfar S. Azmi. NT219, a dual inhibitor of IRS1/2 and STAT3, suppresses cancer stem cell mediated resistance to KRASG12C and KRASG12D inhibitors in solid 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 1939.

Abstract 5100: Multimodal real world data reveals immunogenomic drivers of acquired and primary resistance to immune checkpoint blockade

Abstract Background: Why some patients fail or have short lived response to immune checkpoint blockade (ICB) immunotherapy remains largely unknown. While baseline molecular assessments have provided clues to prognostic factors, insights into resistance drivers remains elusive. This is partially due to the difficulty in getting access to post progression samples from patients that were either primary resistant or developed acquired resistance after an initial response to ICB. Thus, the tumor-intrinsic and -extrinsic features that are selected for during progression and potentially drive primary and acquired resistance to immunotherapy remain underexplored. Methods: To compare clinical features and immunogenomic drivers of acquired and primary resistance to ICB across major cancers, we analysed and annotated de-identified patient records in the Tempus real-world database. We built an immuno-oncology cohort consisting of >2500 multimodal (DNA, RNA and clinical outcome data) pre-treatment baseline with >1500 post-treatment tumour biopsy samples from mainly NSCLC, TNBC, HNC and Bladder cancer patients. We used bulk RNA-seq data to estimate activation of the hallmark oncogenic pathways and immune cell composition and used panel DNA-seq data (>500 genes) to quantify mutation selection at the gene and pathway levels using dndscv. Results: Compared to acquired, primary resistant patients tended to have a higher observation of liver lesions at progression. Post-ICB, acquired resistant NSCLC and HNC patients showed a significantly inflamed tumour microenvironment (TME) characterised by higher estimation of infiltration of T cells and myeloid cells and higher activation of interferon gamma (IFNg) signalling as compared to primary resistant patients. In addition, in post-ICB acquired resistance in NSCLC we observed selection for mutations in genes involved in known immunomodulatory pathways, including loss-of-function mutations in B2M. Consistently, acquired resistance patients showed stronger selection for mutations in Hedgehog and Notch pathways as compared to primary resistance patients across NSCLC, HNC and TNBC post-ICB. Conclusions: Acquired and primary ICB resistant patients have distinct clinical and molecular features at progression. Their tumours’ TME is fundamentally different with acquired resistance TMEs being infiltrated with immune cells albeit escaped post progression. In addition, ICB selects mutations that potentially activate pathways such as Notch and Hedgehog. This multi-modal Real-World Data with post therapy biopsies has given insights for patient selection strategies and provides rational into combination treatment options for acquired resistant patients. Citation Format: Mohamed Reda Keddar, Sebastian Carrasco Pro, Kathleen Burke, Ana Camelo Stewart, Mark Cobbold, Ross Stewart, Sajan Khosla, Ben Sidders, Scott Hammond, Douglas C. Palmer, Jonathan Dry, Martin L. Miller. Multimodal real world data reveals immunogenomic drivers of acquired and primary resistance to immune checkpoint blockade [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 5100.

Abstract A023: Integrating mathematical modeling and in vitro experiments to measure ecological interactions in cancer

Abstract Integrating mathematical modeling and in vitro experiments to measure ecological interactions in cancer Maximilian Strobl, Dagim Tadele, Jeffrey Maltas, Rowan Barker-Clarke, Mina Dinh, Jacob Scott Over the past two decades it has become clear that tumours are complex and evolving ecosystems, in which different cancer cell populations interact with each other and with their non-tumour microenvironment. This understanding has given rise to the intriguing idea that we might be able to leverage these interactions to slow, or even revert, the expansion of resistant cells. In so-called “Adaptive Therapy” (AT) treatment is dynamically reduced to maintain the tumour burden tolerable whilst also preserving a pool of drug-sensitive cells which competitively suppress resistant cells. However, how strong and how common is this suppression, and how do we stratify patients who might benefit from AT from those who should receive standard-of-care continuous therapy? In this contribution, we present development of methodology and initial experimental results aimed at measuring the distribution of ecological interactions between drug-sensitive and resistant cells. Previously, we pioneered an assay with which to quantify ecological interactions in cancer in vitro. In the “Game Assay”, the two populations are co-cultured at a range of initial ratios in 2-D, and we record how the growth rate of each population is modulated by the relative abundance of the other. In the current study, we begin by using an agent-based mathematical model to characterize the accuracy and precision of this assay and how we may improve these by modifying different aspects of the experimental design (number of replicates, number of proportions) and analysis (regression technique, regression window). This shows that the choice of seeding ratios is important in being able to reliably identify interactions and we discuss guidelines for assay design. Upon identifying an interaction, a key next question is the underlying mechanism. Next, we thus use the model to investigate the degree to which we can use the assay to distinguish between local (e.g. contact inhibition) and non-local interactions (e.g. paracrine signaling). To conclude, we present preliminary experimental data in which we have used our optimized protocol to quantify the distribution of interactions between Osimertinib sensitive and resistant NSCLC cells (PC9). Our data show that while suppressive interactions do occur, they vary in their strength between different resistant lineages and can be attenuated in a frequency-dependent manner. Overall, we demonstrate how mathematical models can help in the design and interpretation of experimental assays and we contribute towards a more systematic and quantitative understanding of tumor ecology as a foundation for adaptive therapy. Citation Format: Maximilian A. R. Strobl, Dagim S. Tadele, Jeffrey Maltas, Rowan Barker-Clarke, Mina Dinh, Jacob Scott. Integrating mathematical modeling and in vitro experiments to measure ecological interactions in cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr A023.

Ultrasound-propelled liposome circumvention and siRNA silencing reverse BRAF mutation-arised cancer resistance to trametinib

BRAF-V600E mutation is regarded as the source of lung cancer resistance to trametinib (Tr), and no solution available for completely addressing this intractable resistance has emerged yet. Herein, the combination of ultrasonic (US) propelled folic acid (FA)-modified liposomes strategy and BRAF-driven gene silencing program is proposed to effectively reverse Tr's resistance to lung cancer. Meanwhile, the prepared cationic nanoliposomes can assist Tr drug and BRAF siRNA to escape lysosome disposal, thereby avoiding Tr drug pumping out or siRNA degradation. More significantly, loaded BRAF siRNA is designed to silence BRAF-V600E mutation genes via modulating BRAF-ERK-pathway and remarkably reverse the PC9R resistance to Tr. Systematic experiments validate that these cooperatively sensitize PC9R cells to Tr and shrink resistant NSCLC in vivo, especially after combining with FA-mediated targeting and US-enhanced permeability that permits more intratumoral accumulations of Tr. Such a biocompatible targeting drug-resistance liberation agent and its underlying design strategy lay a foundation avenue to completely reverse tumor resistance, which is preferable to treat BRAF mutation-arised resistance of various tumors, holding high clinical translation potentials.

123P A phase II study of nivolumab (N) plus ipilimumab (I) and ASTX727 or N plus I in PD-1/PD-L1 resistant melanoma or NSCLC patients: The run-in phase of the NIBIT Foundation ML1 study

123P A phase II study of nivolumab (N) plus ipilimumab (I) and ASTX727 or N plus I in PD-1/PD-L1 resistant melanoma or NSCLC patients: The run-in phase of the NIBIT Foundation ML1 study

ZLDI-8 suppresses angiogenesis and vasculogenic mimicry in drug-resistant NSCLC in vitro and in vivo

AimsThe chemotherapy drugs for NSCLC often face the consequences of treatment failure due to acquired drug resistance. Tumor chemotherapy resistance is often accompanied by angiogenesis. Here, we aimed to investigate the effect and underlying mechanisms of ADAM-17 inhibitor ZLDI-8 we found before on angiogenesis and vasculogenic mimicry(VM) in drug-resistant NSCLC. Main methodsThe tube formation assay was used to evaluate angiogenesis and VM. Migration and invasion were assessed with transwell assays in the co-culture condition. To explore the underlying mechanisms of how ZLDI-8 inhibited tubes formation, ELISA assay and western blot assay were preformed. The effects of ZLDI-8 on angiogenesis in vivo were investigated in Matrigel plug, CAM and Rat aortic ring assays. Key findingsIn the present study, ZLDI-8 significantly inhibited the tube formation of human umbilical vein endothelial cells (HUVECs) in either normal medium or in tumor supernatants. Furthermore, ZLDI-8 also inhibited VM tubes formation of A549/Taxol cells. In the co-culture assay, the interaction between lung cancer cells and HUVECs promotes increased cell migration and invasion, while ZLDI-8 eliminates this promotion. Moreover, the VEGF secretion were decreased by ZLDI-8 and the expression of Notch1, Dll4, HIF1α and VEGF were inhibited by ZLDI-8. In addition, ZLDI-8 can inhibit blood vessel formation in the Matrigel plug, CAM and Rat aortic ring assays. SignificanceZLDI-8 inhibits angiogenesis and VM in drug-resistant NSCLC through suppressing Notch1-HIF1α-VEGF signaling pathway. This study lays the foundation for the discovery of drugs that inhibit angiogenesis and VM in drug resistant NSCLC.

Safety and clinical activity of target-preserving anti-CTLA-4 antibody ONC-392 as monotherapy in NSCLC patients who progressed on PD(L)1-targeted immunotherapy.

9024 Background: PD-1 or PD-L1 inhibitors have transformed clinical care of NSCLC patients. However, many patients may develop primary or secondary resistant to PD-(L)1 inhibitors. The marketed anti-CTLA-4 mAbs are ineffective as monotherapy for NSCLC. ONC-392 is a novel target-preserving anti-CTLA-4 antibodies that confers immunotherapeutic effect by selective depletion of regulatory T cells (Treg) in the tumor microenvironment. Preclinical studies show that ONC-392 is more effective and less toxic for immunotherapy than other clinically used anti-CTLA-4 antibodies. In first-in-human study in patients with advanced solid cancer, the recommended Phase 2 dose (RP2D) for ONC-392 monotherapy was established as 10 mg/kg. In this study, we tested safety and clinical activities of ONC-392 in NSCLC patients who progressed on PD(L)1-targeted therapy. Methods: Anti-PD-(L)1 resistant NSCLC patients were enrolled as parts of PRESERVE-001 studies (NCT04140526) expansion cohort Part C Arm I and treated with 2 cycles of 10 mg/kg, followed by 6 mg/kg, q3w, ONC-392 by IV infusion. Safety was evaluated based on treatment emergent and treatment-related adverse events, while efficacy was evaluated by investigators using RECIST1.1 criteria. Results: As of December 18, 2022, 33 NSCLC patients have received at least one dose of ONC-392 at 10 mg/kg. The median age is 66 yrs (range 43 - 89 yr), 61% male. 61% were non-squamous cell carcinoma and 39% were squamous cell carcinoma. 27% are ECOG score 0 and 73% were ECOG score 1. The median prior treatment was 2 cycles (range 1 to 4). The average ONC-392 treatment period was 3.5 cycles (range 1 to 13 cycles). Overall, the patients with TRAE in grade 3 or above is 33% (11/33), including diarrhea/colitis (3, 9%), AST/ALT increase or hepatitis (3, 9%), muscular weakness (2, 6%), nephritis (1, 3%), adrenal insufficiency (1, 3%). Due to pace of enrollment, efficacy data are available in 22 patients. 6 of 22 evaluable patients have partial response and 12 patients have stable disease per RECIST 1.1, resulting in a response rate of 27% and disease control rate of 82% among evaluable patients. The median follow-up period for all patients is 5.8 months and 8.6 months for 20 alive patients (range 2.9 to 14.1 months). The estimated 6- and 12-month overall survival (OS) rates were 65% and 55%. Median OS has not reached. Conclusions: Overall, ONC-392 monotherapy with 10 mg/kg is safe and tolerable. Onc-392 monotherapy has showed encouraging anti-tumor activity in IO-resistant NSCLC when compared with historical data. Based on these encouraging data, we have initiated a Phase 3 study testing ONC-392 monotherapy among NSCLC who progressed on PD(L)1-targeting immunotherapy (NCT05671510). Clinical trial information: NCT04140526 .

3-Phosphoinositide-dependent kinase 1 drives acquired resistance to osimertinib

Osimertinib sensitive and resistant NSCLC NCI-H1975 clones are used to model osimertinib acquired resistance in humanized and non-humanized mice and delineate potential resistance mechanisms. No new EGFR mutations or loss of the EGFR T790M mutation are found in resistant clones. Resistant tumors grown under continuous osimertinib pressure both in humanized and non-humanized mice show aggressive tumor regrowth which is significantly less sensitive to osimertinib as compared with parental tumors. 3-phosphoinositide-dependent kinase 1 (PDK1) is identified as a potential driver of osimertinib acquired resistance, and its selective inhibition by BX795 and CRISPR gene knock out, sensitizes resistant clones. In-vivo inhibition of PDK1 enhances the osimertinib sensitivity against osimertinib resistant xenograft and a patient derived xenograft (PDX) tumors. PDK1 knock-out dysregulates PI3K/Akt/mTOR signaling, promotes cell cycle arrest at the G1 phase. Yes-associated protein (YAP) and active-YAP are upregulated in resistant tumors, and PDK1 knock-out inhibits nuclear translocation of YAP. Higher expression of PDK1 and an association between PDK1 and YAP are found in patients with progressive disease following osimertinib treatment. PDK1 is a central upstream regulator of two critical drug resistance pathways: PI3K/AKT/mTOR and YAP.

Abstract CT034: GLIMMER-01: initial results from a phase 1 dose escalation trial of a first-in-class bi-sialidase (E-602) in solid tumors

Abstract Background: Hypersialylation (excessive sialoglycans) on tumor cells has been known to be associated with poorer cancer outcomes for more than 40 years. Sialoglycans are immune suppressive and promote tumor immune evasion by binding to sialoglycan receptors (e.g. Siglecs) expressed on immune cells. However, redundant immune cell expression among Siglecs has posed a challenge for receptor-targeting therapeutic approaches. E-602 is a first-in-class fusion protein of engineered human sialidase (Neu2) and a human IgG1 Fc region. The dimeric sialidase moieties of E-602 circumvent the redundancy of this biology by directly cleaving terminal sialic acid residues from sialoglycans on immune and tumor cells. In preclinical studies, E-602 enhanced immune function by augmenting antigen-specific priming and activation of T cells and restoring function of exhausted-like T cells, and E-602 demonstrated antitumor activity as monotherapy in multiple mouse tumor models. Methods: A Phase 1/2 first-in-human dose escalation study is evaluating the safety, pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity of E-602 in patients with advanced cancers. Eligible patients with select advanced solid tumors were treated with E-602 IV once weekly at dose levels between 1 and 30 mg/kg. Circulating immune cells were analyzed for changes in sialylation and immunophenotyping by flow cytometry. Changes in circulating cytokines were measured by immunoassays. Results: As of January 6, 2023, 32 patients were treated with at least one dose of E-602. The most common tumors treated were colorectal (n=18) and pancreatic (n=6). Doses up to 30 mg/kg were tolerated with no dose-limiting toxicities. The most frequent adverse event was infusion-related reactions which were primarily grade 1-2 and clinically manageable. PK was linear across the evaluated dose range with an estimated T1/2 of 9-24 hours. Dose dependent PD observations included (1) desialylation of peripheral CD8+ T, CD4+ T, and NK cells, remaining detectable in some patients at 7 days post-dose; (2) increases in the immune activation marker, CD69, on peripheral CD8+ T, CD4+ T, and NK cells; and (3) increases in the IFNγ-dependent chemokine CXCL10, TNF-α, and MIP1-β. Thus far, response-evaluable patients have had stable or progressive disease. Additional safety, PK, PD, and clinical outcomes for other patients treated as part of backfill at multiple dose levels will be reported at the meeting. Conclusion: E-602 is tolerated at doses up to 30 mg/kg. Consistent with preclinical findings, dose-dependent desialylation and immune system activation were observed. Based on the observed tolerability and PD effects, the Phase 2 portion of the study to evaluate clinical activity of E-602 monotherapy in patients with checkpoint-inhibitor resistant NSCLC and melanoma will proceed. Citation Format: Jason J. Luke, Melissa Johnson, Anthony Tolcher, Christopher T. Chen, Tong Dai, Brendan D. Curti, Anthony El-Khoueiry, Mario Sznol, Brian S. Henick, Christine Horak, Pushpa Jayaraman, Christopher B. Cole, Dawn Wilson, Lizhi Cao, Li Peng, David Feltquate, Deanne Lathers, Manish R. Sharma. GLIMMER-01: initial results from a phase 1 dose escalation trial of a first-in-class bi-sialidase (E-602) in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT034.

Abstract 5120: NPRL2 gene therapy induces effective antitumor immunity in KRAS/STK11 mutant anti-PD1 resistant metastatic human NSCLC in a humanized mouse model

Abstract NPRL2/TUSC4 is a potent tumor suppressor gene whose expression is reduced in many cancers including NSCLC. Restoration of NPRL2 expression in cancer cells induces DNA damages which leads to cell cycle arrest and apoptosis. We investigated the antitumor immune responses to NPRL2 gene therapy on anti-PD1 resistant KRAS/STK11 mutant NSCLC in a humanized mouse model. H1299 cells transfected with NPRL2 showed significant inhibition of colony formation after NPRL2 transfection. Humanized mice were generated by transplanting fresh human cord blood derived CD34 stem cells into sub-lethally irradiated NSG mice. The level of engraftment of human CD45, CD3 T, CD19 B, NK cells was verified before tumor implantation. Mice harboring > 25% human CD45 cells were considered humanized. KRAS/STK11 mutant anti-PD1 resistant A549 NSCLC cells were injected intravenously into humanized NSG mice and developed lung metastasis. Metastases were treated with intravenous injection of NPRL2 gene loaded cationic lipid nanoparticles with or without pembrolizumab (anti-PD1). A dramatic antitumor effect was mediated by NPRL2 treatment, whereas pembrolizumab was ineffective. A significant antitumor effect was also found in non-humanized NSG mice, although the effect was greater in humanized mice suggesting that the possible role of antitumor immunity. The antitumor effect of NPRL2 was associated with increased infiltration of human CD45, CD3 T, cytotoxic T, NK cells, and a decreased number of human regulatory T cells (Treg) in tumors. PD1 expressing exhausted CD8 T cells were downregulated in both the NPRL2 and pembrolizumab groups. The number of activated T cells (CD69+CD8+T), effector (EM) and central memory (CM) CD8 T cells were significantly increased by NPRL2 treatment. NPRL2 induced antigen presenting HLA-DR+ dendritic cells. When NPRL2 was combined with pembrolizumab, no synergistic antitumor effect was found in the KRAS/STK11 mutant anti-PD1 insensitive tumors. However, a robust and synergistic antitumor effect was observed in the KRAS wild type, anti-PD1 sensitive H1299 tumors grown in humanized mice treated with NPRL2 + pembrolizumab. Cytotoxic T cells, NK cells, and HLA-DR+ DC were associated with the antitumor effect. DOTAP-NPRL2 was tested in a syngeneic mouse model with LLC2 tumors that are KRAS mutant and anti-PD1 resistant. Consistent with the A549 humanized mouse model, NPRL2 showed a significantly strong antitumor effect whereas anti-PD1 was not effective in this model. The antitumor effect of NPRL2 was again correlated with the upregulation of HLA-DR+ DC, CD11c DC, TILs, NK and downregulation of Treg and myeloid cells in the tumor microenvironment. Taken together, these data suggest that NPRL2 gene therapy induces antitumor activity on KRAS/STK11 mutant anti-PD1 resistant tumors through DC mediated antigen presentation and cytotoxic immune cell activation. Citation Format: Ismail M. Meraz, Mourad Majidi, Renduo Song, Feng Meng, Gao Lihui, Qi Wang, Jing Wang, Elizabeth Shpall, Jack A. Roth. NPRL2 gene therapy induces effective antitumor immunity in KRAS/STK11 mutant anti-PD1 resistant metastatic human NSCLC in a humanized mouse model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5120.