Efficacy Of Inhibitors Research Articles

Discovery of Novel Inhibitors of Cruzain Cysteine Protease of Trypanosoma cruz.

Chagas disease (CD) is a parasitic disease endemic in several developing countries. According to the World Health Organization, approximately 6-8 million people worldwide are inflicted by CD. The scarcity of new drugs, mainly for the chronic phase, is the main reason for treatment limitation in CD. Therefore, there is an urgent need to discover new targets for which new therapeutical agents could be developed. Cruzain cysteine protease (CCP) is a promising alternative because this enzyme exhibits pleiotropic effects by acting as a virulence factor, modulating host immune cells, and interacting with host cells. This systematic review was conducted to discover new compounds that act as cruzain inhibitors, and their effects in vitro were studied through enzymatic assays and molecular docking. Additionally, the advances and perspectives of these inhibitors are discussed. These findings are expected to contribute to medicinal chemistry in view of the design of new, safe, and efficacious inhibitors against Trypanosoma cruzi CCP detected in the last decade (2013-2022) to provide scaffolds for further optimization, aiming toward the discovery of new drugs.

A novel Natural killer cell-related gene signature for improving the prediction of prognosis and immunotherapy response in bladder cancer.

Bladder cancer (BLCA) is a commonly diagnosed cancer worldwide that exhibits high rates of recurrence and metastasis. Immunotherapy is increasingly being recognised in the clinical management of bladder cancer. In addition, the prospect of developing Natural Killer (NK) cell-related immunotherapy is promising in BLCA. We established and verified a prognostic signature based on NK cell-related gene expression. We then calculated the NKscore of BLCA samples and correlated it with the clinical outcomes, molecular subtypes of BLCA, tumour microenvironment (TME), and predicted efficacy of immune checkpoint inhibitors (ICI) and chemotherapy drugs to thoroughly explore the implications of the NKscore. Finally, the role of the NK signature gene HECTD1 in BLCA was verified by Quantitative Real-time PCR, Cell Counting Kit-8 Assay (CCK-8), Transwell Assay and Colony Formation Experiment. We analysed NK cell-associated genes and identified six genes with significant prognostic relevance. A high NK score significantly represents a worse prognosis. NKscore was significantly correlated with seven types of classical molecular subtype classifications of BLCA. In addition, NKscore positively correlates with NK-related immune checkpoints, suggesting that emerging NK cell immune checkpoint inhibitors, such as monalizumab, may have potential therapeutic promise for patients with high NKscore. The results of the T cell inflamed score (TIS) and tumour immune dysfunction exclusion (TIDE) score confirmed the suitability of immunotherapy for patients with a high NK score. Likewise, patients with a high NK score may be more suitable for several significant chemotherapeutic drugs. Functional experiments showed that the knockdown of HECTD1 significantly attenuated the proliferation, migration, and invasion ability of tumour cells. to sum up, the capability of our signature to predict prognosis and immunotherapy response was robust. Hopefully, these results will provide new insights for BLCA research and patient immunotherapy.

Development of Tumor Markers for Breast Cancer Immunotherapy.

Although breast cancer treatment has been developed remarkably in recent years, it remains the primary cause of death among women. Immune checkpoint blockade therapy has significantly altered the way breast cancer is treated, although not all patients benefit from the changes. At present, the most effective mechanism of immune checkpoint blockade application in malignant tumors is not clear and efficacy may be influenced by many factors, including host, tumor, and tumor microenvironment dynamics. Therefore, there is a pressing need for tumor immunomarkers that can be used to screen patients and help determine which of them would benefit from breast cancer immunotherapy. At present, no single tumor marker can predict treatment efficacy with sufficient accuracy. Multiple markers may be combined to more accurately pinpoint patients who will respond favorably to immune checkpoint blockade medication. In this review, we have examined the breast cancer treatments, developments in research on the role of tumor markers in maximizing the clinical efficacy of immune checkpoint inhibitors, prospects for the identification of novel therapeutic targets, and the creation of individualized treatment plans. We also discuss how tumor markers can provide guidance for clinical practice.

Design, Synthesis, and Pharmacological Evaluation of Spiro[carbazole-3,3'-pyrrolidine] Derivatives as cGAS Inhibitors for Treatment of Acute Lung Injury.

Overactivation of cyclic GMP-AMP synthase (cGAS) is implicated in the occurrence of many inflammatory and autoimmune diseases, and inhibition of cGAS with a specific inhibitor has been proposed as a potential therapeutic strategy. However, only a few low-potency cGAS inhibitors have been reported, and few are suitable for clinical investigation. As a continuation of our structural optimization on the reported cGAS inhibitor 6 (G140), we developed a series of spiro[carbazole-3,3'-pyrrolidine] derivatives bearing a unique 2-azaspiro[4.5]decane structural motif, among which compound 30d-S was identified with high cellular effects against cGAS. This compound showed improved plasma exposure, lower clearance, and an oral bioavailability of 35% in rats. Moreover, in the LPS-induced acute lung injury (ALI) mice model, oral administration of compound 30d-S at 30 mg/kg markedly reduced lung inflammation and alleviated histopathological changes. These results confirm that 30d-S is a new efficacious cGAS inhibitor and is worthy of further investigation.

Enhancing Corrosion Resistance of Mild Steel in 1M HCl: Investigation of New Benzoxazepine Derivatives Through Synthesis, Electrochemical Analysis, Surface Analysis, XPS, DFT, and Molecular Dynamics Simulation

AbstractThis research delineates the corrosion inhibitory efficiency of two newly synthesized benzoxazepine derivatives – [3,3‐dimethyl‐11‐phenyl‐3,4,5,11‐tetrahydrodibenzo[b,e] [1,4]oxazepine‐1(2 H)‐one (S1)] and [11‐(4‐chlorophenyl)‐3,3‐dimethyl‐3,4,5,11‐tetrahydrodibenzo[b,e][1,4]oxazepine‐1(2 H)‐one (S2)] – on mild steel in 1M HCl milieu. These derivatives were characterized by proton (1H NMR) and carbon (13C NMR) nuclear magnetic resonance spectroscopy. The experimental approach encompassed potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. The corrosion inhibition efficacy of S1 and S2 was concentration‐dependent, with their efficiencies peaking at 92.0 % and 92.1 %, respectively, at a 10−3 M concentration. Surface characterization, conducted using scanning electron microscopy (SEM), energy‐dispersive X‐ray analysis (EDS), X‐ray diffraction (XRD), contact angle measurements, and X‐ray photoelectron spectroscopy (XPS), corroborated the formation of a protective barrier layer on the mild steel surface. Additionally, using an inductive approach, UV‐visible spectrometry was employed to elucidate the adsorption behaviors of these inhibitors on the steel surface. Density functional theory (DFT) and molecular dynamics (MD) simulations were utilized to decipher the interaction mechanisms and adsorption modalities, unveiling critical insights into the interactions of S1 and S2 with the mild steel surface. This comprehensive analysis highlights the robust corrosion inhibition potential of the newly synthesized benzoxazepine derivatives and illuminates their prospective utility as effective inhibitors for mild steel in corrosive environments.

Efficacy and safety of tyrosine kinase inhibitors for advanced metastatic thyroid cancer: A systematic review and network meta-analysis of randomized controlled trials.

Tyrosine kinase inhibitors (TKIs) have been approved for treating patients with clinically advanced metastatic thyroid cancer. However among the many TKIs, it remains unknown which regimen is the best choice for these patients. We conducted a systematic review and network meta-analysis to compare the survival benefits and efficacy of the available first-line regimens. We conducted an active search for phase II, III, or IV randomized controlled trials (RCTs) in the PubMed, Embase, and Cochrane databases to compare the effects of at least 2 drugs in the systemic treatment of advanced or metastatic thyroid cancer up to May 2023. The network meta-analysis model was adjusted using Bayesian Network model. Twelve trials with 2535 patients were included in our meta-analysis. The overall survival (OS), progression-free survival (PFS), and serious adverse events (SAEs) were taken as reference indicators. We also performed subgroup analyses of OS and PFS in medullary thyroid cancer (MTC) and radioiodine-refractory differentiated thyroid cancer (RR-DTC) to explore the variations of TKIs in different groups. As a result, apatinib had the best effect on overall survival (OS) (hazards ratio [HR] = 0.42, 95% confidence interval [CI] = 0.18-0.98), lenvatinib 18 mg/d has the best effect on progression-free survival (PFS) (HR = 0.13, 95% CI = 0.064-0.27), and cabozantinib 60 mg/d has the best safety profile. Our network meta-analysis showed that we believe that cabozantinib has the potential to become a widely used drug in clinical practice.

Huang Lian Jie Du Decoction enhances the anti-tumor efficacy of immune checkpoint inhibitors by activating TLR7/8 signalling in melanoma

BackgroundThe clinical application of immune checkpoint inhibitors (ICIs) is limited by their drug resistance, necessitating the development of ICI sensitizers to improve cancer immunotherapy outcomes. Huang Lian Jie Du Decoction (HLJD, Oren-gedoku-to in Japanese, Hwangryunhaedok-tang in Korean), a famous traditional Chinese medicinal prescription, has exhibited potential in the field of cancer treatment. This study aims to investigate the impact of HLJD on the efficacy of ICIs in melanoma and elucidate the underlying mechanisms.MethodsThe potential synergistic effects of HLJD and ICIs were investigated on the tumor-bearing mice model of B16F10 melanoma, and the tumor infiltration of immune cells was tested by flow cytometry. The differential gene expression in tumors between HLJD and ICIs group and ICIs alone group were analyzed by RNA-seq. The effects of HLJD on oxidative stress, TLR7/8, and type I interferons (IFN-Is) signaling were further validated by immunofluorescence, PCR array, and immunochemistry in tumor tissue.ResultsHLJD enhanced the anti-tumor effect of ICIs, significantly inhibited tumor growth, and prolonged the survival duration in melanoma. HLJD increased the tumor infiltration of anti-tumor immune cells, especially DCs, CD4+ T cells and CD8+T cells. Mechanically, HLJD activated the oxidative stress and TLR7/8 signaling pathway and IFN-Is-related genes in tumors.ConclusionsHLJD enhanced the therapeutic benefits of ICIs in melanoma, through increasing reactive oxygen species (ROS), promoting the TLR7/8 pathway, and activating IFN-Is signaling, which in turn activated DCs and T cells.

Antiangiogenic-immune-checkpoint inhibitor combinations: lessons from phase III clinical trials.

Antiangiogenic agents, generally antibodies or tyrosine-kinase inhibitors that target the VEGF-VEGFR pathway, are currently among the few combination partners clinically proven to improve the efficacy of immune-checkpoint inhibitors (ICIs). This benefit has been demonstrated in pivotal phase III trials across different cancer types, some with practice-changing results; however, numerous phase III trials have also had negative results. The rationale for using antiangiogenic drugs as partners for ICIs relies primarily on blocking the multiple immunosuppressive effects of VEGF and inducing several different vascular-modulating effects that can stimulate immunity, such as vascular normalization leading to increased intratumoural blood perfusion and flow, and inhibition of pro-apoptotic effects of endothelial cells on T cells, among others. Conversely, VEGF blockade can also cause changes that suppress antitumour immunity, such as increased tumour hypoxia, and reduced intratumoural ingress of co-administered ICIs. As a result, the net clinical benefits from antiangiogenic-ICI combinations will be determined by the balance between the opposing effects of VEGF signalling and its inhibition on the antitumour immune response. In this Perspective, we summarize the results from the currently completed phase III trials evaluating antiangiogenic agent-ICI combinations. We also discuss strategies to improve the efficacy of these combinations, focusing on aspects that include the deleterious functions of VEGF-VEGFR inhibition on antitumour immunity, vessel co-option as a driver of non-angiogenic tumour growth, clinical trial design, or the rationale for drug selection, dosing and scheduling.

Impact of concurrent medications on clinical outcomes of cancer patients treated with immune checkpoint inhibitors: analysis of Health Insurance Review and Assessment data

PurposeMedications regulating immune homeostasis and gut microbiota could affect the efficacy of immune checkpoint inhibitors (ICIs). This study aimed to investigate the impact of concurrent medications on the clinical outcomes of patients with cancer receiving ICI therapy in South Korea.MethodsWe identified patients newly treated with ICI for non-small cell lung cancer (NSCLC), urothelial carcinoma (UC), and malignant melanoma (MM) between August 2017 and June 2020 from a nationwide database in Korea. The effect of concurrent antibiotics (ATBs), corticosteroids (CSs), proton-pump inhibitors (PPIs), and opioids prescribed within 30 days before ICI initiation on the treatment duration and survival was assessed.ResultsIn all, 8870 patients were included in the ICI cohort (NSCLC, 7,128; UC, 960; MM, 782). The patients were prescribed ATBs (33.8%), CSs (47.8%), PPIs (28.5%), and opioids (53.1%) at the baseline. The median overall survival durations were 11.1, 12.2, and 22.1 months in NSCLC, UC, and MM subgroups, respectively, since starting the ICI mostly as second-line (NSCLC and UC) and first-line (MM) therapy. Early progression was observed in 34.2% of the patients. Opioids and CS were strongly associated with poor survival across all cancer types. A high number of concurrent medications was associated with early progression and short survival. Opioid and CS use was associated with poor prognosis in all patients treated with ICIs. However, ATBs and PPIs had a cancer-specific effect on survival.ConclusionA high number of concurrent medications was associated with poor clinical outcomes.

Graphene Quantum Dots Eradicate Resistant and Metastatic Cancer Cells by Enhanced Interfacial Inhibition.

Drug-resistant and metastatic cancer cells such as a small population of cancer stem cells (CSCs) play a crucial role in metastasis and relapse. Conventional small-molecule chemotherapeutics, however, are unable to eradicate drug-resistant CSCs owing to limited interface inhibitory effects, leading to chemotherapy failure. Herein, we report that enhanced interfacial inhibition leading to eradication of drug-resistant CSCs can be dramatically induced by self insertion of bioactive graphene quantum dots (GQDs) into DNA major groove (MAG) sites in cancer cells. Since transcription factors regulate gene expression at the MAG site, MAG-targeted GQDs exert greatly enhanced interfacial inhibition, down-regulating the expression of a collection of cancer stem genes such as ALDH1, Notch1, and Bmi1. Moreover, the nanoscale interface inhibition mechanism reverses cancer multidrug resistance (MDR) by inhibiting MDR1 gene expression when GQDs are used at a non-toxic concentration (1/4×IC50) as the MDR reverser. Given their high efficacy in interfacial inhibition, CSC-mediated migration, invasion and metastasis of cancer cells can be substantially blocked by MAG-targeted GQDs, which can also be harnessed to sensitize clinical cytotoxic agents for improved efficacy in combination chemotherapy. Our findings elucidate the inhibitory effects of the enhanced nano-bio interface at the MAG site on eradicating CSCs, thus preventing cancer metastasis and recurrence. This article is protected by copyright. All rights reserved.

Efficacy of Cyclooxygenase-2 Inhibitors for Headache in Acute Brain Injury: A Systematic Review (P7-12.006)

Efficacy of Cyclooxygenase-2 Inhibitors for Headache in Acute Brain Injury: A Systematic Review (P7-12.006)

Blocking lipid synthesis induces DNA damage in prostate cancer and increases cell death caused by PARP inhibition.

Androgen deprivation therapy (ADT) is the primary treatment for prostate cancer; however, resistance to ADT invariably develops, leading to castration-resistant prostate cancer (CRPC). Prostate cancer progression is marked by increased de novo synthesis of fatty acids due to overexpression of fatty acid synthase (FASN), making this enzyme a therapeutic target for prostate cancer. Inhibition of FASN results in increased intracellular amounts of ceramides and sphingomyelin, leading to DNA damage through the formation of DNA double-strand breaks and cell death. We found that combining a FASNi with the poly-ADP ribose polymerase (PARP) inhibitor olaparib, which induces cell death by blocking DNA damage repair, resulted in a more pronounced reduction in cell growth than that caused by either drug alone. Human CRPC organoids treated with a combination of PARP and FASNi were smaller, had decreased cell proliferation, and showed increased apoptosis and necrosis. Together, these data indicate that targeting FASN increases the therapeutic efficacy of PARP inhibitors by impairing DNA damage repair, suggesting that combination therapies should be explored for CRPC.

Microsatellite instability and mismatch repair protein deficiency: equal predictive markers?

Current clinical guidelines recommend mismatch repair (MMR) protein immunohistochemistry (IHC) or molecular microsatellite instability (MSI) tests as predictive markers of immunotherapies. Most of the pathological guidelines consider MMR protein IHC as the gold standard test to identify cancers with MMR deficiency and recommend molecular MSI tests only in special circumstances or to screen for Lynch syndrome. However, there are data in the literature which suggest that the two test types may not be equal. For example, molecular epidemiology studies reported different rates of deficient MMR (dMMR) and MSI in various cancer types. Additionally, direct comparisons of the two tests revealed relatively frequent discrepancies between MMR IHC and MSI tests, especially in non-colorectal and non-endometrial cancers and in cases with unusual dMMR phenotypes. There are also scattered clinical data showing that the efficacy of immune checkpoint inhibitors is different if the patient selection was based on dMMR versus MSI status of the cancers. All these observations question the current dogma that dMMR phenotype and genetic MSI status are equal predictive markers of the immunotherapies.

Efficacy of CGRP Inhibitors in Preventive Pharmacotherapy for Migraine—A Network Meta-analysis and Systematic Review (P8-12.005)

Efficacy of CGRP Inhibitors in Preventive Pharmacotherapy for Migraine—A Network Meta-analysis and Systematic Review (P8-12.005)

Safety and clinical efficacy of immune checkpoint inhibitors in advanced gastric cancer in the real world.

To evaluate the clinical efficacy and safety of immune checkpoint inhibitors in patients with advanced gastric cancer in the real world. The retrospective analysis was conducted on the clinical records of 402 patients with advanced gastric cancer who were admitted to the Nanjing Drum Tower Hospital between December 2017 and April 2022 and who had received immunotherapy. Observation target: drug use, treatment, adverse reaction type and grade, objective response rate (ORR), disease control rate (DCR), progression free survival (PFS), and overall survival (OS). By retrospectively analyzing the data of patients with advanced gastric cancer treated with ICIs previously admitted to our medical center, we found some clinical characteristic factors associated with the occurrence of irAEs as well as the efficacy and prognosis: the presence or absence of hypertension, whether or not to receive targeted therapies can predict the occurrence of immune-related adverse events (irAEs), and the more the presence of irAEs, the better the prognosis. These can help clinicians in clinical drug selection. The results of this paper show that the occurrence of irAEs is associated with patients' OS. irAEs occurrence can prolong patients' OS. irAEs occurrence may serve as a surrogate marker for ICIs.

Evaluating homologous recombination activity in tissues to predict the risk of hereditary breast and ovarian cancer and olaparib sensitivity.

Homologous recombination (HR) repairs DNA damage including DNA double-stranded breaks and alterations in HR-related genes results in HR deficiency. Germline alteration of HR-related genes, such as BRCA1 and BRCA2, causes hereditary breast and ovarian cancer (HBOC). Cancer cells with HR deficiency are sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors and DNA-damaging agents. Thus, accurately evaluating HR activity is useful for diagnosing HBOC and predicting the therapeutic effects of anti-cancer agents. Previously, we developed an assay for site-specific HR activity (ASHRA) that can quantitatively evaluate HR activity and detect moderate HR deficiency. HR activity in cells measured by ASHRA correlates with sensitivity to the PARP inhibitor, olaparib. In this study, we applied ASHRA to lymphoblastoid cells and xenograft tumor tissues, which simulate peripheral blood lymphocytes and tumor tissues, respectively, as clinically available samples. We showed that ASHRA could be used to detect HR deficiency in lymphoblastoid cells derived from a BRCA1 pathogenic variant carrier. Furthermore, ASHRA could quantitatively measure the HR activity in xenograft tumor tissues with HR activity that was gradually suppressed by inducible BRCA1 knockdown. The HR activity of xenograft tumor tissues quantitatively correlated with the effect of olaparib. Our data suggest that ASHRA could be a useful assay for diagnosing HBOC and predicting the efficacy of PARP inhibitors.

Association of the Advanced Lung Cancer Inflammation Index (ALI) and Gustave Roussy Immune (GRIm) score with immune checkpoint inhibitor efficacy in patients with gastrointestinal and lung cancer

ObjectiveThis study aimed to conduct a comprehensive analysis, evaluating the prognostic significance of the baseline Advanced Lung Cancer Inflammation Index (ALI) and Gustave Roussy Immune (GRIm) Score in patients undergoing immune checkpoint inhibitor (ICI) therapy.MethodsA comprehensive search was performed across various databases, including PubMed, the Cochrane Library, EMBASE, and Google Scholar, until October 21, 2023, to compile relevant articles for analysis. The investigation encompassed diverse clinical outcomes, including overall survival (OS) and progression-free survival (PFS).ResultsThis analysis included a total of 15 articles, comprising 19 studies involving 3335 patients. Among the 19 studies, nine studies focused on NSCLC, and six studies were conducted on HCC. Pooled results revealed that patients with elevated ALI levels experienced prolonged OS (HR: 0.51, 95% CI: 0.37–0.70, p < 0.001) and extended PFS (HR: 0.61, 95% CI: 0.52–0.72, p < 0.001). Furthermore, a GRIm score > 1 was associated with reduced OS (HR: 2.07, 95% CI: 1.47–2.92, p < 0.001) and diminished PFS (HR: 1.78, 95% CI: 1.35–2.34, p < 0.001) in cancer patients receiving ICIs. Subgroup analysis indicated that ALI cutoff values of 18 exhibited enhanced predictive potential. Additionally, for HCC patients, those with HCC-GRIm score > 2 showed a substantially decreased risk of mortality compared to individuals with HCC-GRIm score ≤ 2 (HR: 2.63, 95% CI: 1.89–3.65, p < 0.001).ConclusionThe ALI and GRIm score served as dependable prognostic indicators for patients undergoing ICI therapy in the context of cancer treatment.

FePd Nanozyme- and SKN-Encapsulated Functional Lipid Nanoparticles for Cancer Nanotherapy via ROS-Boosting Necroptosis.

Cell necroptosis has presented great potential, acting as an effective approach against tumor apoptotic resistance, and it could be further enhanced via accompanying reactive oxygen species (ROS) overexpression. However, whether overproduced ROS assists the necroptotic pathway remains unclear. Thus, iron-palladium nanozyme (FePd NZ)- and shikonin (SKN)-encapsulated functional lipid nanoparticles (FPS-LNPs) were designed to investigate the ROS overexpression-enhanced SKN-induced necroptosis. In this system, SKN acts as an effective necroptosis inducer for cancer cells, and FePd NZ, a sensitive Fenton reaction catalyst, produces extra-intracellular ROS to reinforce the necroptotic pathway. Both in vitro and in vivo antitumor evaluation revealed that FPS-LNPs presented the best tumor growth inhibition efficacy compared with FP-LNPs or SKN-LNPs alone. Meanwhile, induced necroptosis by FPS-LNPs can further trigger the release of damage-associated molecular patterns (DAMPs) and antigens from dying tumor cells to activate the innate immune response. Taking biosafety into consideration, this study has provided a potential nanoplatform for cancer nanotherapy via inducing necroptosis to avoid apoptosis resistance and activate CD8+ T cell immune response.

Progress of lymphocyte activation gene 3 and programmed cell death protein 1 antibodies for cancer treatment: A review.

The application of immune checkpoint inhibitors has proven to be an effective treatment for cancer. Immune checkpoints such as programmed cell death protein 1/programmed cell death protein 1 ligand 1 (PD-1/PD-L1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T-cell immunoglobulin-3 (TIM-3), T-cell immunoglobulin and ITIM domain (TIGIT), and lymphocyte activation gene-3 (LAG-3) have received extensive attention, and the efficacy of antibodies or inhibitors against these checkpoints (either alone or in combination) has been evaluated in many tumors. This paper provides a brief overview of the PD-1 and LAG-3 checkpoints, and then shifts focus to the combined use of PD-1 and LAG-3 antibodies in both in vivo and in vitro experiments. In the in vitro experiments, we examined the correlation between the expression and activation of these inhibitors on T cells, and also assessed toxicity in animals in preparation for in vivo experiments. The effects of the combined use of PD-1 and LAG-3 antibodies were then summarized in animal models of melanoma, MC38 carcinoma, and other tumors. In clinical studies, the combined application of these antibodies was assessed in patients with melanoma, colorectal, breast, and renal cell cancers, as well as other solid tumors. In general, the combination of PD-1 and LAG-3 antibodies has shown promising results in both in vivo and in vitro studies.

Abstract LB077: CSF-1R inhibition with Pimicotinib (ABSK021) enhanced anti-tumor efficacy of KRASG12C inhibitors in preclinical non-small cell lung cancer mouse models

Abstract Background: KRAS mutations are highly prevalent oncogenic drivers in human cancers and KRASG12C is the most frequent mutations found in KRAS-mutant non-small lung cancer (NSCLC). It is reported that tumor associated macrophages (TAMs) are enriched in KRAS-driven transgenic lung cancer models. Depletion of macrophage results in a significant decrease in tumor burden and increased survival. Sotorasib (AMG510), the first KRASG12C inhibitor approved by FDA, has been found to modulate tumor immunity, impacting the recruitment of macrophages. CSF-1R signaling is critical for macrophage proliferation and survival. CSF-1R inhibition depletes TAMs and reprograms tumor microenvironment (TME), resulting in enhancement of anti-tumor immunity. Therefore, the combination of KRASG12C and CSF-1R inhibitors may synergize to enhance anti-tumor efficacy. Pimicotinib (ABSK021) is a potential best-in-class small molecule inhibitor of CSF-1R in clinical development of multiple indications. Here, we conducted in vivo experiments to explore the combined effects of KRASG12C and CSF-1R inhibitors. Methods: In vivo efficacy studies were performed to evaluate the combined treatment of KRASG12C inhibitors (AMG510 and ABSK071, a next-generation inhibitor targeting KRASG12C with better inhibitory activity) and CSF-1R inhibitor (ABSK021) in NCI-H2122 PBMC humanized mice and LLC syngeneic mice. RNA sequencing was employed to investigate the mechanism of action underlying the synergistic anti-tumor effect. Immunohistochemistry (IHC) was utilized to examine the changes of immune cell populations in TME. Results: The combinatory regimen of ABSK021 and KRASG12C inhibitors showed improved anti-tumor effects than each single agent alone in both mouse NSCLC models. Bioinformatics and follow-up analysis revealed a reduction in immune suppressive TAMs in tumors treated with ABSK021 alone or in combination with KRASG12C inhibitors. Furthermore, modulation of TME related to anti-tumor immunity, such as activated CD4 T, CD8 T and NK cells, was increased, and pro-tumor immunity, such as MDSC, regulatory T cells, was decreased in combination group. IHC results confirmed that ABSK021 addition led to macrophage depletion and more CD8 T cell infiltration in TME. Conclusions: For the first time, we demonstrate that the combined inhibition of KRASG12C and CSF-1R leads to superior therapeutic efficacy in preclinical NSCLC mouse models. This results suggests a potential novel therapeutic regimen that could yield improved clinical benefit to patients. Citation Format: Nannan Zhang, Bin Shen, Shenyan Liu, Cheng Dai, Haiyan Ying, Fushen Guo, Zhixuan Zhu, Wan Shi, Min Tu, Jie Wang, Jie Zhang, Manqi Liu, Qi Zhang, Zhui Chen. CSF-1R inhibition with Pimicotinib (ABSK021) enhanced anti-tumor efficacy of KRASG12C inhibitors in preclinical non-small cell lung cancer mouse models [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 LB077.