Subset Of Cancer Patients Research Articles

The baseline hemoglobin level is a positive biomarker for immunotherapy response and can improve the predictability of tumor mutation burden for immunotherapy response in cancer.

Because only a subset of cancer patients can benefit from immunotherapy, identifying predictive biomarkers of ICI therapy response is of utmost importance. We analyzed the association between hemoglobin (HGB) levels and clinical outcomes in 1,479 ICIs-treated patients across 16 cancer types. We explored the dose-dependent associations between HGB levels and survival and immunotherapy response using the spline-based cox regression analysis. Furthermore, we investigated the associations across subgroups of patients with different clinicopathological characteristics, treatment programs and cancer types using the bootstrap resampling method. HGB levels correlated positively with clinical outcomes in cancer patients receiving immunotherapy but not in those without immunotherapy. Moreover, this association was independent of other clinicopathological characteristics (such as sex, age, tumor stage and tumor mutation burden (TMB)), treatment program and cancer type. Also, this association was independent of the established biomarkers of immunotherapy response, including TMB, PD-L1 expression and microsatellite instability. The combination of TMB and HGB level are more powerful in predicting immunotherapy response than TMB alone. Multi-omics analysis showed that HGB levels correlated positively with antitumor immune signatures and negatively with tumor properties directing antitumor immunosuppression, such as homologous recombination defect, stemness and intratumor heterogeneity. The HGB measure has the potential clinical value as a novel biomarker of immunotherapy response that is easily accessible from clinically routine examination. The combination of TMB and HGB measures have better predictive performance for immunotherapy response than TMB.

A combination of protein phosphatase 2A inhibition and checkpoint immunotherapy: a perfect storm.

Immune checkpoint blockade has emerged as a potent new tool in the war on cancer. However, only a subset of cancer patients benefit from this therapeutic modality, sparking a search for combination therapies to increase the fraction of responding patients. We argue here that inhibition of protein phosphatase 2A (PP2A) is a promising approach to increase responses to immune checkpoint blockade and other therapies that rely on the presence of tumor-reactive Tcells. Inhibition of PP2A increases neoantigen expression on tumor cells, activates the cGAS/STING pathway, suppresses regulatory Tcells, and increases cytotoxic Tcell activation. In preclinical models, inhibition of PP2A synergizes with immune checkpoint blockade and emerging evidence indicates that patients who have tumors with mutations in PP2A respond better to immune checkpoint blockade. Therefore, inhibition of PP2A activity may be an effective way to sensitize cancer cells to immune checkpoint blockade and cell-based therapies using tumor-reactive Tcells.

Challenges in the Development of NK-92 Cells as an Effective Universal Off-the-Shelf Cellular Therapeutic.

The human-derived NK-92 cell-based CAR-NK therapy exhibits inconsistency with overall suboptimal efficacy and rapid invivo clearance of CAR-NK92 cells in cancer patients. Analysis indicates that although pre-existing IgM in healthy individuals (n = 10) strongly recognizes both NK-92 and CAR-NK92 cells, IgG and IgE do not. However, only a subset of cancer patients (3/8) exhibit strong IgM recognition of these cells, with some (2/8) showing pre-existing IgG recognition. These results suggest a natural immunoreactivity between NK-92 and CAR-NK92 cells and pre-existing human Abs. Furthermore, the therapy's immunogenicity is evidenced by enhanced IgG and IgM recognition postinfusion of CAR-NK92 cells. We also confirmed that healthy plasma's cytotoxicity toward these cells is reduced by complement inhibitors, suggesting that Abs may facilitate the rapid clearance of CAR-NK92 cells through complement-dependent cytotoxicity. Given that NK-92 cells lack known receptors for IgG and IgM, identifying and modifying the recognition targets for these Abs on NK-92 and CAR-NK92 cells may improve clinical outcomes. Moreover, we discovered that the 72nd amino acid of the NKG2D receptor on NK-92 cells is alanine. Previous studies have demonstrated polymorphism at the 72nd amino acid of the NKG2D on human NK cells, with NKG2D72Thr exhibiting a superior activation effect on NK cells compared with NKG2D72Ala. We confirmed this conclusion also applies to NK-92 cells by invitro cytotoxicity experiments. Therefore, reducing the immunoreactivity and immunogenicity of CAR-NK92 and directly switching NK-92 bearing NKG2D72Ala to NKG2D72Thr represent pressing challenges in realizing NK-92 cells as qualified universal off-the-shelf cellular therapeutics.

Microbiota-induced plastic T cells enhance immune control of antigen-sharing tumors.

Therapies that harness the immune system to target and eliminate tumor cells have revolutionized cancer care. Immune checkpoint blockade (ICB), which boosts the anti-tumor immune response by inhibiting negative regulators of T cell activation1-3, is remarkably successful in a subset of cancer patients, yet a significant proportion do not respond to treatment, emphasizing the need to understand factors influencing the therapeutic efficacy of ICB4-9. The gut microbiota, consisting of trillions of microorganisms residing in the gastrointestinal tract, has emerged as a critical determinant of immune function and response to cancer immunotherapy, with multiple studies demonstrating association of microbiota composition with clinical response10-16. However, a mechanistic understanding of how gut commensal bacteria influence the efficacy of ICB remains elusive. Here we utilized a gut commensal microorganism, segmented filamentous bacteria (SFB), which induces an antigen-specific Th17 cell effector program17, to investigate how colonization with it affects the efficacy of ICB in restraining distal growth of tumors sharing antigen with SFB. We find that anti-PD-1 treatment effectively inhibits the growth of implanted SFB antigen-expressing melanoma only if mice are colonized with SFB. Through T cell receptor clonal lineage tracing, fate mapping, and peptide-MHC tetramer staining, we identify tumor-associated SFB-specific Th1-like cells derived from the homeostatic Th17 cells induced by SFB colonization in the small intestine lamina propria. These gut-educated ex-Th17 cells produce high levels of the pro-inflammatory cytokines IFN-γ and TNF-α, and promote expansion and effector functions of CD8+ tumor-infiltrating cytotoxic lymphocytes, thereby controlling tumor growth. A better understanding of how distinct intestinal commensal microbes can promote T cell plasticity-dependent responses against antigen-sharing tumors may allow for the design of novel cancer immunotherapeutic strategies.

Opioid Use and Gut Dysbiosis in Cancer Pain Patients.

Opioids are commonly used for the management of severe chronic cancer pain. Their well-known pharmacological effects on the gastrointestinal system, particularly opioid-induced constipation (OIC), are the most common limiting factors in the optimization of analgesia, and have led to the wide use of laxatives and/or peripherally acting mu-opioid receptor antagonists (PAMORAs). A growing interest has been recently recorded in the possible effects of opioid treatment on the gut microbiota. Preclinical and clinical data, as presented in this review, showed that alterations of the gut microbiota play a role in modulating opioid-mediated analgesia and tolerability, including constipation. Moreover, due to the bidirectional crosstalk between gut bacteria and the central nervous system, gut dysbiosis may be crucial in modulating opioid reward and addictive behavior. The microbiota may also modulate pain regulation and tolerance, by activating microglial cells and inducing the release of inflammatory cytokines and chemokines, which sustain neuroinflammation. In the subset of cancer patients, the clinical meaning of opioid-induced gut dysbiosis, particularly its possible interference with the efficacy of chemotherapy and immunotherapy, is still unclear. Gut dysbiosis could be a new target for treatment in cancer patients. Restoring the physiological amount of specific gut bacteria may represent a promising therapeutic option for managing gastrointestinal symptoms and optimizing analgesia for cancer patients using opioids.

The gut microbial characteristics and underlying mechanisms of patients with different clinical prognoses from immunotherapy by landmark analysis.

2606 Background: A subset of cancer patients could benefit long-termly from immune checkpoints inhibitors (ICIs), which was called smearing effect. Gut microbiota was widely found to be associated with the initial ICIs efficacy and immune-related adverse event (irAE). This study aimed to identify the baseline gut microbiota characteristics of long-benefit patients and explore the possible underlying mechanisms. Methods: Lung cancer patients initially treated with anti-PD-1/PD-L1 therapy were consecutively enrolled from May 2020 to September 2022. All patients were classified into Benefit group, Resistance group and Severe irAE group based on the long-term prognosis. The baseline gut microbiota characteristics were identified by metagenome sequencing. MelonnPan was used to predict the abundances of 79 metabolites. The sequences of autoantigen, lung cancer antigen and anticancer peptides (ACPs) from IEDB and CancerPPD databases were aligned against the scaftigs of fecal samples. Results: 54 patients were enrolled with 24 in Benefit group, 13 in Severe irAE group and 17 in Resistance group. The microorganism composition was significantly different between Benefit group and Resistance group ( P=0.03), while no difference between Benefit group and Severe irAE group ( P=0.93). The co-occurrence network showed the Benefit group patients had the most compact microbiota network. Metabolites prediction analyses showed the short chain fatty acids propionate ( P=0.005) and butyrate/isobutyrate ( P=0.03) were significantly enriched in Benefit group than Resistance group, wherein the acetyl-CoA pathway ( P=0.04) accounted for the largest proportion of butyrate-production ability difference. The beneficial species had more positive correlations with butyrate-producing enzymes ( P<0.001). The microbiota of irAE patients had abundant aligned sequences with antigen epitopes of multiple autoimmune diseases. The total counts of systemic lupus erythematosus-related epitopes were significantly more enriched in patients with immune-related colitis ( P=0.04), especially FDNGRRGRPVTGP ( P=0.02) and IDNGRRGRPITGP ( P=0.02). Likewise, the microbiota of patients with good ICIs efficacy tended to have more abundant cancer-related antigen counts ( P=0.07) and ACPs counts ( P=0.06). Strain-level analysis revealed Escherichia coli and Faecalibacterium prausnitziishowed a centralized trend of genomic variations based on different clinical phenotypes. Conclusions: Long-term benefit patients had converging characteristics of gut microbiota, which coevoluted a compact microbial community with high butyrate-producing ability. The microbiota molecular mimicry of autoimmune and tumor antigen might contribute to irAE and ICIs efficacy. The strain-level genomic variations of specific species may also play a role in clinical phenotypes.

Physician justification for anti-cancer treatment decisions in the evolving oncology market.

e23317 Background: Oncology is a rapidly expanding pharmaceutical space, driven by innovative research and clinical technology. Continued growth in anti-cancer therapy has generated an exceedingly competitive market. As treatment options increase, physicians must weigh a variety of factors to make individualized care decisions. Many elements are patient-specific, but physician biases may also impact selection. As the market evolves, it is unknown whether oncology providers will shift priorities to align with contemporary findings or continue to trust in historical experiences. Methods: The Ipsos Global Oncology Monitor is an online, multi-center medical chart review of oncology patients receiving drug therapy. Over 1,900 cancer-treating physicians in the United States were screened for seniority and caseload and submitted data on 253,051 cancer patients (aggregate; all tumor types) between January 2020 to December 2023. Upon record submission, physicians were prompted to select up to three responses most associated with the reason for prescribing the reported therapy. Responses were chosen from a finite list of closed-ended options. Results: Influence of “Approved Standard of Care” fell amongst sampled physicians, cited as a reason for selecting treatment in 61% of reported annual patients in 2023, declining by 2.94 percentage points since 2020. “Biomarker results” recorded increased influence on therapy selection, rising in association with 8% of reported patients in 2020 to 11% in 2023. Within tumor-specific cohorts, “Maintain/improve quality of life” was a notable reason for drug therapy decisions in both breast and colorectal cancer patient subsets in 2023 (10% and 19% respectively). Contrary to the overall patient cohort, drug therapy choice for reported prostate cancer patients has increasingly shown association with “Approved Standard of Care” (53% in 2020 to 60% in 2023). Conclusions: Results of this study highlight the evolution of factors influencing anti-cancer treatment decisions in sampled physicians. Sampled providers appear to be shifting away from universal treatments, as shown by lowered association with “Approved Standard of Care”. Sampled physicians seem to be opting for specific therapies, demonstrated by rising influence of “Biomarker results”. Discrepancies between tumors merit expansion of research in rarer indications and emphasize the importance of diagnostic testing to continue improving quality of care. Further investigation using comparator cohort is warranted.

Cost-effectiveness analysis of a cardio-oncology rehabilitation framework compared to an exercise intervention for cancer survivors with high cardiovascular risk.

A cardio-oncology rehabilitation model among cancer survivors showed superior results comparing to a community-based exercise intervention. However, questions remain about its cost-effectiveness. To assess the cost-effectiveness of a center-based cardiac rehabilitation (CBCR) program when compared to usual care encompassing a community-based exercise training (CBET), among cancer survivors with high cardiovascular risk. The CORE study was a single-center, prospective, randomized controlled trial; 80 adult cancer survivors with previous exposure to cardiotoxic cancer treatment and/or with previous cardiovascular disease were assigned (1:1 ratio) to an 8-week CBCR or CBET, twice/week. Cost-effectiveness was a pre-specified secondary endpoint. Outcomes included healthcare resource use and costs, quality-adjusted life-years (QALYs) and cost-effectiveness; incremental cost-effectiveness ratio (ICER) was computed from a societal perspective. 75 patients completed the study (CBCR N=38; CBET N=37). The CBCR had significantly higher cost per patient (477.76 ± 39.08€) compared to CBET group (339.32 ± 53.88€), with a significant between-group difference 138.44€ (95% CI, 116.82 to 160.05€, p<0.01). A between-group difference by 0.100 points in QALYs was observed, favouring the CBCR (95% CI, -0.163 to -0.037, p=0.002). When CBCR was compared with CBET, the ICER was €1,383.24 per QALY gained; at a willingness-to-pay threshold of €5,000 per QALY, the probability of CBCR being cost-effective was 99.9% (95% CI, 99.4 to 100.0). The CORE trial shows that a CBCR is a cost-effective intervention in the management of cancer survivors with high cardiovascular risk, reinforcing the potential benefits of this multidisciplinary approach in supportive care of this specific subset of cancer patients.

Emerging Innate Immune Cells in Cancer Immunotherapy: Promises and Challenges.

Immune checkpoint inhibitor (ICI)-based therapy has made an unprecedented impact on survival benefit for a subset of cancer patients; however, only a subset of cancer patients is benefiting from ICI therapy if all cancer types are considered. With the advanced understanding of interactions of immune effector cell types and tumors, cell-based therapies are emerging as alternatives to patients who could not benefit from ICI therapy. Pioneering work of chimeric antigen receptor T (CAR-T) therapy for hematological malignancies has brought encouragement to a broad range of development for cellular-based cancer immunotherapy, both innate immune cell-based therapies and T-cell-based therapies. Innate immune cells are important cell types due to their rapid response, versatile function, superior safety profiles being demonstrated in early clinical development, and being able to utilize multiple allogeneic cell sources. Efforts on engineering innate immune cells and exploring their therapeutic potential are rapidly emerging. Some of the therapies, such as CD19 CAR natural killer (CAR-NK) cell-based therapy, have demonstrated comparable early efficacy with CD19 CAR-T cells. These studies underscore the significance of developing innate immune cells for cancer therapy. In this review, we focus on the current development of emerging NK cells, γδ T cells, and macrophages. We also present our views on potential challenges and perspectives to overcome these challenges.

Pan-cancer analysis implicates novel insights of lactate metabolism into immunotherapy response prediction and survival prognostication

BackgroundImmunotherapy has emerged as a potent clinical approach for cancer treatment, but only subsets of cancer patients can benefit from it. Targeting lactate metabolism (LM) in tumor cells as a method to potentiate anti-tumor immune responses represents a promising therapeutic strategy.MethodsPublic single-cell RNA-Seq (scRNA-seq) cohorts collected from patients who received immunotherapy were systematically gathered and scrutinized to delineate the association between LM and the immunotherapy response. A novel LM-related signature (LM.SIG) was formulated through an extensive examination of 40 pan-cancer scRNA-seq cohorts. Then, multiple machine learning (ML) algorithms were employed to validate the capacity of LM.SIG for immunotherapy response prediction and survival prognostication based on 8 immunotherapy transcriptomic cohorts and 30 The Cancer Genome Atlas (TCGA) pan-cancer datasets. Moreover, potential targets for immunotherapy were identified based on 17 CRISPR datasets and validated via in vivo and in vitro experiments.ResultsThe assessment of LM was confirmed to possess a substantial relationship with immunotherapy resistance in 2 immunotherapy scRNA-seq cohorts. Based on large-scale pan-cancer data, there exists a notably adverse correlation between LM.SIG and anti-tumor immunity as well as imbalance infiltration of immune cells, whereas a positive association was observed between LM.SIG and pro-tumorigenic signaling. Utilizing this signature, the ML model predicted immunotherapy response and prognosis with an AUC of 0.73/0.80 in validation sets and 0.70/0.87 in testing sets respectively. Notably, LM.SIG exhibited superior predictive performance across various cancers compared to published signatures. Subsequently, CRISPR screening identified LDHA as a pan-cancer biomarker for estimating immunotherapy response and survival probability which was further validated using immunohistochemistry (IHC) and spatial transcriptomics (ST) datasets. Furthermore, experiments demonstrated that LDHA deficiency in pancreatic cancer elevated the CD8+ T cell antitumor immunity and improved macrophage antitumoral polarization, which in turn enhanced the efficacy of immunotherapy.ConclusionsWe unveiled the tight correlation between LM and resistance to immunotherapy and further established the pan-cancer LM.SIG, holds the potential to emerge as a competitive instrument for the selection of patients suitable for immunotherapy.

Circulating tumor cells shielded with extracellular vesicle-derived CD45 evade T cell attack to enable metastasis

Circulating tumor cells (CTCs) are precursors of distant metastasis in a subset of cancer patients. A better understanding of CTCs heterogeneity and how these CTCs survive during hematogenous dissemination could lay the foundation for therapeutic prevention of cancer metastasis. It remains elusive how CTCs evade immune surveillance and elimination by immune cells. In this study, we unequivocally identified a subpopulation of CTCs shielded with extracellular vesicle (EVs)-derived CD45 (termed as CD45+ CTCs) that resisted T cell attack. A higher percentage of CD45+ CTCs was found to be closely correlated with higher incidence of metastasis and worse prognosis in cancer patients. Moreover, CD45+ tumor cells orchestrated an immunosuppressive milieu and CD45+ CTCs exhibited remarkably stronger metastatic potential than CD45− CTCs in vivo. Mechanistically, CD45 expressing on tumor surfaces was shown to form intercellular CD45-CD45 homophilic interactions with CD45 on T cells, thereby preventing CD45 exclusion from TCR-pMHC synapse and leading to diminished TCR signaling transduction and suppressed immune response. Together, these results pointed to an underappreciated capability of EVs-derived CD45-dressed CTCs in immune evasion and metastasis, providing a rationale for targeting EVs-derived CD45 internalization by CTCs to prevent cancer metastasis.

Abstract 6558: Ultra-sensitive ctDNA detection predicts response to immune checkpoint inhibition in advanced melanoma patients

Abstract Immune checkpoint inhibition (ICI) provides clinical benefit to a subset of cancer patients. Monitoring circulating tumor DNA (ctDNA) in peripheral blood may allow clinicians to predict ICI response or resistance earlier than imaging and track response more frequently. In this study, melanoma patients receiving ICI were profiled using an ultra-sensitive, tumor-informed ctDNA detection platform, and the findings were correlated with clinical outcome. In this retrospective study, 188 plasma samples were collected from 23 advanced melanoma patients receiving immune checkpoint inhibitor (ICI) treatment, spanning a period of up to 40 months. Levels of ctDNA were then profiled using the NeXT Personal® assay. NeXT Personal is a liquid biopsy platform that utilizes whole-genome sequencing of tumor and normal samples to create a customized panel for each patient, encompassing up to 1,800 genetic somatic variants. This enables the detection of molecular residual disease (MRD) down to a limit of detection (LOD) of 1-3 parts per million (PPM). We subsequently compared the results obtained through NeXT Personal with RECIST-defined measurements and clinical outcomes. Ultra-sensitive ctDNA detection was achieved across a wide dynamic range, spanning from 2.3 PPM to over 130,000 PPM (median LOD = 2 PPM). A significant number of detections were attained at low PPM levels, with 30% (31/105) occurring below 100 PPM and 25% (26/105) occurring below 50 PPM. 94% (17/18) of baseline samples were ctDNA+ among patients without recent second-line therapy, including all patients who progressed. All ctDNA+ detections aligned with imaging results that indicated the presence of tumor. Likewise, all plasma timepoints corresponding to complete responses (CR) assessed via RECIST were ctDNA-. Early increase in ctDNA from baseline to treatment cycle 3 significantly predicted PFS (log-rank 0.003; Wald p=0.01, HR=8.35, 95% CI 1.62-43.15). Survival was predicted by both imaging CR (log-rank p=0.018) and ctDNA clearance (log-rank p=0.003). Molecular progression, defined as a 20% increase in ctDNA, significantly predicted OS (log-rank p=0.023), whereas imaging PD status did not predict OS (log-rank p=0.09). We achieved detection of ctDNA with an LOD down to 1.3 PPM in this cohort, with nearly a third of detections occurring below 100 PPM, suggesting the importance of an ultra-sensitive ctDNA approach even in late stage patients. Our findings suggest that ctDNA changes arepredictive of ICI response in late stage melanoma. These results highlight the potential for patient-specific ctDNA monitoring to inform patient management and for clincal trial design. Citation Format: Christoffer Gebhardt, Laura Keller, Isabel Heidrich, Julian Koett, Glenn Geidel, Daniel J. Smit, Ronald Simon, Stefan W. Schneider, Jason Pugh, Charles W. Abbott, Sean Boyle, Richard O. Chen, Klaus Pantel. Ultra-sensitive ctDNA detection predicts response to immune checkpoint inhibition in advanced melanoma patients [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 6558.

Is there an association between lymph node size and hyperprogression in immunotherapy-treated patients?

Hyperprogressive disease (HPD) can be described as an accelerated increase in the growth rate of tumors combined with rapid clinical deterioration observed in a subset of cancer patients undergoing immunotherapy, specifically with immune checkpoint inhibitors (ICIs). The reported incidence of HPD ranges from 5.9% to 43.1% in patients receiving ICIs. In this context, identifying reliable predictive risk factors for HPD is crucial as it may allow for earlier intervention and ultimately improve patient outcomes. This study retrospectively analyzed ten metastatic renal cell carcinoma (mRCC) patients. The identification of HPD was based on the diagnostic criteria proposed by Ferrara R et al. This study aimed to investigate whether there is an association between LN size and HPD using a cutoff value of 3 cm for LN size. Given the limited sample size, Fisher's exact test was used to test this association. We conducted a Kaplan-Meier (KM) analysis to estimate the median overall survival (OS) of patients with HPD and compared it to those without HPD. Three patients (30%) developed HPD, while seven (70%) did not. Fisher's exact test revealed a statistically significant association between the HPD and LN size ≥ 3 cm (p=0.008). In the HPD group, the median OS was significantly shorter, with a median OS of 3 months, whereas in the non-HPD group, the median OS was not reached (P =0.001). The present study found a significant association between LN size ≥ 3 cm in the pretreatment period and HPD development.

Beyond the Barrier: Unraveling the Mechanisms of Immunotherapy Resistance.

Immune checkpoint blockade (ICB) induces a remarkable and durable response in a subset of cancer patients. However, most patients exhibit either primary or acquired resistance to ICB. This resistance arises from a complex interplay of diverse dynamic mechanisms within the tumor microenvironment (TME). These mechanisms include genetic, epigenetic, and metabolic alterations that prevent T cell trafficking to the tumor site, induce immune cell dysfunction, interfere with antigen presentation, drive heightened expression of coinhibitory molecules, and promote tumor survival after immune attack. The TME worsens ICB resistance through the formation of immunosuppressive networks via immune inhibition, regulatory metabolites, and abnormal resource consumption. Finally, patient lifestyle factors, including obesity and microbiome composition, influence ICB resistance. Understanding the heterogeneity of cellular, molecular, and environmental factors contributing to ICB resistance is crucial to develop targeted therapeutic interventions that enhance the clinical response. This comprehensive overview highlights key mechanisms of ICB resistance that may be clinically translatable.

HKDC1 promotes tumor immune evasion in hepatocellular carcinoma by coupling cytoskeleton to STAT1 activation and PD-L1 expression

Immune checkpoint blockade (ICB) has shown considerable promise for treating various malignancies, but only a subset of cancer patients benefit from immune checkpoint inhibitor therapy because of immune evasion and immune-related adverse events (irAEs). The mechanisms underlying how tumor cells regulate immune cell response remain largely unknown. Here we show that hexokinase domain component 1 (HKDC1) promotes tumor immune evasion in a CD8+ T cell-dependent manner by activating STAT1/PD-L1 in tumor cells. Mechanistically, HKDC1 binds to and presents cytosolic STAT1 to IFNGR1 on the plasma membrane following IFNγ-stimulation by associating with cytoskeleton protein ACTA2, resulting in STAT1 phosphorylation and nuclear translocation. HKDC1 inhibition in combination with anti-PD-1/PD-L1 enhances in vivo T cell antitumor response in liver cancer models in male mice. Clinical sample analysis indicates a correlation among HKDC1 expression, STAT1 phosphorylation, and survival in patients with hepatocellular carcinoma treated with atezolizumab (anti-PD-L1). These findings reveal a role for HKDC1 in regulating immune evasion by coupling cytoskeleton with STAT1 activation, providing a potential combination strategy to enhance antitumor immune responses.

Inhibitors of Immune Checkpoints: Small Molecule- and Peptide-Based Approaches.

The revolutionary progress in cancer immunotherapy, particularly the advent of immune checkpoint inhibitors, marks a significant milestone in the fight against malignancies. However, the majority of clinically employed immune checkpoint inhibitors are monoclonal antibodies (mAbs) with several limitations, such as poor oral bioavailability and immune-related adverse effects (irAEs). Another major limitation is the restriction of the efficacy of mAbs to a subset of cancer patients, which triggered extensive research efforts to identify alternative approaches in targeting immune checkpoints aiming to overcome the restricted efficacy of mAbs. This comprehensive review aims to explore the cutting-edge developments in targeting immune checkpoints, focusing on both small molecule- and peptide-based approaches. By delving into drug discovery platforms, we provide insights into the diverse strategies employed to identify and optimize small molecules and peptides as inhibitors of immune checkpoints. In addition, we discuss recent advances in nanomaterials as drug carriers, providing a basis for the development of small molecule- and peptide-based platforms for cancer immunotherapy. Ongoing research focused on the discovery of small molecules and peptide-inspired agents targeting immune checkpoints paves the way for developing orally bioavailable agents as the next-generation cancer immunotherapies.

Polarization of M2 Tumor-Associated Macrophages (TAMs) in Cancer Immunotherapy.

We have witnessed in the last decade new milestones in the treatment of various resistant cancers with new immunotherapeutic modalities. These advances have resulted in significant objective durable clinical responses in a subset of cancer patients. These findings strongly suggested that immunotherapy should be considered for the treatment of all subsets of cancer patients. Accordingly, the mechanisms underlying resistance to immunotherapy must be explored and develop new means to target these resistant factors. One of the pivotal resistance mechanisms in the tumor microenvironment (TME) is the high infiltration of tumor-associated macrophages (TAMs) that are highly immunosuppressive and responsible, in large part, of cancer immune evasion. Thus, various approaches have been investigated to target the TAMs to restore the anti-tumor immune response. One approach is to polarize the M2 TAMS to the M1 phenotype that participates in the activation of the anti-tumor response. In this review, we discuss the various and differential properties of the M1 and M2 phenotypes, the molecular signaling pathways that participate in the polarization, and various approaches used to target the polarization of the M2 TAMs into the M1 anti-tumor phenotype. These approaches include inhibitors of histone deacetylases, PI3K inhibitors, STAT3 inhibitors, TLR agonists, and metabolic reprogramming. Clearly, due to the distinct features of various cancers and their heterogeneities, a single approach outlined above might only be effective against some cancers and not others. In addition, targeting by itself may not be efficacious unless used in combination with other therapeutic modalities.

Immune Evasion in Cancer Is Regulated by Tumor-Asociated Macrophages (TAMs): Targeting TAMs.

Recent advancements in cancer treatment have explored a variety of approaches to address the needs of patients. Recently, immunotherapy has evolved as an efficacious treatment for various cancers resistant to conventional therapies. Hence, significant milestones in immunotherapy were achieved clinically in a large subset of cancer patients. Unfortunately, some cancer types do not respond to treatment, and among the responsive cancers, some patients remain unresponsive to treatment. Consequently, there is a critical need to examine the mechanisms of immune resistance and devise strategies to target immune suppressor cells or factors, thereby allowing for tumor sensitivity to immune cytotoxic cells. M2 macrophages, also known as tumor-associated macrophages (TAMs), are of interest due to their role in suppressing the immune system and influencing antitumor immune responses through modulating T cell activity and immune checkpoint expression. TAMs are associated with signaling pathways that modulate the tumor microenvironment (TME), contributing to immune evasion. One approach targets TAMs, focusing on preventing the polarization of M1 macrophages into the protumoral M2 phenotype. Other strategies focus on direct or indirect targeting of M2 macrophages through understanding the interaction of TAMs with immune factors or signaling pathways. Clinically, biomarkers associated with TAMs' immune resistance in cancer patients have been identified, opening avenues for intervention using pharmacological agents or immunotherapeutic approaches. Ultimately, these multifaceted approaches are promising in overcoming immune resistance and improving cancer treatment outcomes.

Abstract C080: Ultra-high concentration nitric oxide (UNO) enhances anti-CTLA-4 treatment activity and induces a durable anti-tumor immune response

Abstract Background: CTLA-4 blockade is a highly effective therapeutic modality but only in a subset of cancer patients. We previously demonstrated that intratumoral administration of ultra-high concentration nitric oxide (UNO) augmented response to the immune checkpoint inhibitor, anti-mPD-1. Specifically, more than half of the mice treated with 10-minutes UNO (50,000 ppm) and anti-mPD-1 were primary and secondary tumor-free at Day 100 post-UNO treatment (vs 25% of control mice treated with anti-mPD-1 alone). In addition, the combination of UNO and anti-mCTLA-4 assessed in an immunocompetent breast cancer model (4T1) demonstrated prolonged survival in mice compared to single-agent anti-mCTLA-4. In CT26 and 4T1 mice, the immunodominant AH-1 antigen is associated with anti-tumor immune response. In this study, we assessed the systemic levels of CD8+ T-cells recognizing the AH-1 antigen following UNO treatment and the association with anti-tumor response. Methods: Here we explored the effects of UNO treatment in combination with anti-mCTLA-4 therapy. Colon carcinoma (CT26) tumor-bearing mice were treated with intra-tumoral 100,000 ppm UNO for 5 minutes in combination with 5 mg/kg (IP) anti-mCTLA-4. Effects on tumor growth and anti-tumor immune response were assessed. AH-1 specific CD8+ T cells were quantified by flow cytometry. Results: Combining 100,000 ppm UNO with anti-mCTLA4 in CT26 tumor-bearing mice resulted in considerable growth delay and regression of treated tumors. Furthermore, the combination induced a strong systemic response that led to the rejection of a distant metastasis-like tumor inoculated on the contralateral flank. Specifically, at Day 7 post-treatment, all UNO treated mice exhibited tumor-specific CD8+ T-cells in the blood and to a higher degree than in untreated mice. Moreover, systemic levels of tumor-specific CD8+ T-cells were higher in mice treated with the combination of UNO and anti-mCTLA4 compared to mice treated with monotherapy anti-mCTLA-4, indicating an increase in immune surveillance following UNO treatment. Finally, cured mice treated with combination therapy displayed higher systemic levels of antigen-specific CD8+ T-cells compared to untreated or naïve mice. Conclusion: UNO stimulates a higher tumor-specific T-cell response than anti-mCTLA-4 and synergizes with this drug to generate an even more significant targeted immune response. Citation Format: Yogev Sela, Matan Goldshtein, Jedidiah M. Monson, Hila Confino, Amir Avniel, Mark D. Pegram, Selena Chaisson. Ultra-high concentration nitric oxide (UNO) enhances anti-CTLA-4 treatment activity and induces a durable anti-tumor immune response [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 C080.

Abstract C003: A quantitative mass spectrometry workflow for highly multiplexed measurement of immunomodulatory proteins to support immunotherapy clinical trials

Abstract Background: Since the approval of the first immune checkpoint-directed immunotherapies, it has been well-known that the efficacy of these therapies has been limited to a subset of cancer patients. As the number of new potential immunotherapy targets has grown, including novel combination therapy strategies, improved immune-related biomarker measurement has played a key role in understanding novel mechanisms of action and response to drugs. To support these efforts, we have developed an analytically validated assay for the multiplexed quantitation of up to 113 immunomodulatory proteins in various matrices (e.g., human plasma, PBMC, cells, or tissue) based on anti-peptide immunoaffinity capture followed by LC-MRM mass spectrometry analysis. Methods: Remnant samples from commercial biobanks were acquired in a variety of solid tumor indications. Briefly, matrices were denatured, reduced, alkylated, and digested using trypsin. Immunoaffinity capture of the peptide targets consisted of overnight incubation of the digested sample with anti-peptide antibodies coupled to protein G magnetic beads, followed by automated washing and elution of the peptides from the antibodies using the KingFisher platform. The peptides were analyzed in a multiplexed method by LC-MRM mass spectrometry. Endogenous levels for each target were measured relative to a stable isotopically labeled peptide standard. Results: In panel experiments, we found that the targets can be quantified precisely and accurately over 3 orders of magnitude with an intra-/inter-assay precision and accuracy of less than 20%. In total, 107 peptide targets were detected endogenously in cell lines. We expand on these data with analysis of solid tumor FFPE specimens where the results will be compared to immunohistochemical staining for selected targets. Conclusions: This study shows how multiplex immunoaffinity methods can complement classical methods of tissue-based protein expression for simultaneous and quantitative interpretation of protein levels. Citation Format: Ons Ousji, Anne Jang, Luca Genovesi, Nicholas Dupuis, Timon Geib, Gwenael Pottiez, Michael Schirm. A quantitative mass spectrometry workflow for highly multiplexed measurement of immunomodulatory proteins to support immunotherapy clinical trials [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 C003.