Immunotherapy Outcome In Patients Research Articles

Therapeutic Targeting of Thioredoxin Reductase 1 Causes Ferroptosis while Potentiating Anti-PD-1 Efficacy in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) faces low response rates to anti-PD-1 immunotherapies, highlighting the need for enhanced treatment strategies. Auranofin, which inhibits thioredoxin reductase (TrxR) through its gold-based composition, has shown potential in cancer treatment. It targets the TrxR system, essential for safeguarding cells from oxidative stress. The overproduction of TrxR in cancerous cells supports their proliferation. However, auranofin's interference with this system can upset the cellular redox equilibrium, boost levels of reactive oxygen species, and trigger the death of cancer cells. This study is the first to highlight TXNRD1 as a crucial factor contributing to resistance to anti-PD-1 treatment in HNSCC. In this study, we identified targetable regulators of resistance to immunotherapy-induced ferroptosis in HNSCC. We observed a link of thioredoxin reductase 1 (TXNRD1) with tumoral PD-L1 expression and ferroptosis suppression in HNSCC. Moreover, HNSCC tumors with aberrant TXNRD1 expression exhibited a lack of PD-1 response, NRF2 overexpression, and PD-L1 upregulation. TXNRD1 inhibition promoted ferroptosis in HNSCC cells with NRF2 activation and in organoid tumors derived from patients lacking a PD-1 response. Mechanistically, TXNRD1 regulated PD-L1 transcription and maintained the redox balance by binding to ribonucleotide reductase regulatory subunit M2 (RRM2). TXNRD1 expression disruption sensitized HNSCC cells to anti-PD-1–mediated Jurkat T-cell activation, promoting tumor killing through ferroptosis. Moreover, TXNRD1 inhibition through auranofin cotreatment synergized with anti-PD-1 therapy to potentiate immunotherapy-mediated ferroptosis by mediating CD8+ T-cell infiltration and downregulating PD-L1 expression. Our findings indicate that targeting TXNRD1 is a promising therapeutic strategy for improving immunotherapy outcomes in patients with HNSCC.

Targeting nucleotide metabolic pathways in colorectal cancer by integrating scRNA-seq, spatial transcriptome, and bulk RNA-seq data

BackgroundColorectal cancer is a malignant tumor of the digestive system originating from abnormal cell proliferation in the colon or rectum, often leading to gastrointestinal symptoms and severe health issues. Nucleotide metabolism, which encompasses the synthesis of DNA and RNA, is a pivotal cellular biochemical process that significantly impacts both the progression and therapeutic strategies of colorectal cancerMethodsFor single-cell RNA sequencing (scRNA-seq), five functions were employed to calculate scores related to nucleotide metabolism. Cell developmental trajectory analysis and intercellular interaction analysis were utilized to explore the metabolic characteristics and communication patterns of different epithelial cells. These findings were further validated using spatial transcriptome RNA sequencing (stRNA-seq). A risk model was constructed using expression profile data from TCGA and GEO cohorts to optimize clinical decision-making. Key nucleotide metabolism-related genes (NMRGs) were functionally validated by further in vitro experiments.ResultsIn both scRNA-seq and stRNA-seq, colorectal cancer (CRC) exhibited unique cellular heterogeneity, with myeloid cells and epithelial cells in tumor samples displaying higher nucleotide metabolism scores. Analysis of intercellular communication revealed enhanced signaling pathways and ligand-receptor interactions between epithelial cells with high nucleotide metabolism and fibroblasts. Spatial transcriptome sequencing confirmed elevated nucleotide metabolism states in the core region of tumor tissue. After identifying differentially expressed NMRGs in epithelial cells, a risk prognostic model based on four genes effectively predicted overall survival and immunotherapy outcomes in patients. High-risk group patients exhibited an immunosuppressive microenvironment and relatively poorer prognosis and responses to chemotherapy and immunotherapy. Finally, based on data analysis and a series of cellular functional experiments, ACOX1 and CPT2 were identified as novel therapeutic targets for CRC.ConclusionIn this study, a comprehensive analysis of NMRGs in CRC was conducted using a combination of single-cell sequencing, spatial transcriptome sequencing, and high-throughput data. The prognostic model constructed with NMRGs shows potential as a standalone prognostic marker for colorectal cancer patients and may significantly influence the development of personalized treatment approaches for CRC.

Abstract 4969: Investigating digital pathology tumor microenvironment features for immunotherapy outcome in patients with advanced non-small cell lung cancer

Abstract Introduction The composition of the tumor microenvironment (TME) has been shown to influence response to immunotherapy (IO). In this study, we investigated digital pathology TME features of IO outcomes among patients with non-squamous, non-small cell lung cancer (NSCLC) within a real-world dataset. Methods From the nationwide de-identified Flatiron Health-Foundation Medicine NSCLC clinico-genomic database, a cohort of 50 EGFR/ALK-negative, non-squamous NSCLC patients treated with first-line pembrolizumab monotherapy (mono-IO) or pembrolizumab in combination with carboplatin/cisplatin and pemetrexed (chemo-IO) that had available whole slide images of H&E-stained tissue resection specimens were included. The de-identified data originated from approximately 280 US cancer clinics (~800 sites of care). AI-powered TME characterization models developed by PathAI (Boston, MA; commercially available as PathExplore™) were deployed on scanned H&E slides to extract a panel of cell- and tissue-level human interpretable features (HIFs). Cox proportional hazards regression was used to identify digital pathology features or HIFs associated with overall survival. Results 17 HIFs were associated with better survival and 19 HIFs were associated with worse survival among patients treated with mono-IO (p < 0.05). Lymphocyte features were among the HIFs associated with favorable survival, including density of lymphocyte cells in cancer epithelium (hazard ratio (HR) per unit standard deviation (SD) = 0.46 [0.24, 0.88], p-value = 0.02) and proportion of lymphocyte cells relative to total immune cells in cancer epithelium (HR per unit SD = 0.61 [0.39, 0.95], p-value = 0.03). Cell-level features associated with worse survival included density of fibroblast cells in stroma (HR per unit SD = 1.51 [1.01, 2.25], p-value = 0.05). These associations remained after adjusting for tumor mutational burden (TMB) (N = 29 low, 21 high) and PD-L1 status (N = 0 negative, 1 low-positive, 17 high-positive, 32 unknown). Additionally, similar associations were not observed among patients treated with chemo-IO. High lymphocyte density was associated with better survival compared to low lymphocyte density in mono-IO treated patients (adjusted HR per unit SD = 0.36 [0.18, 0.74], p-value = 0.01) but not in chemo-IO treated patients (adjusted HR per unit SD = 1.10 [0.76, 1.60], p-value = 0.6). Conclusion These results indicate that the composition of TME assessed via digital pathology may have utility in identifying NSCLC patients that will respond to first-line immune checkpoint inhibitors beyond the established IO biomarkers. Citation Format: Ericka M. Ebot, Kuei-Ting Chen, Mikayla Biggs, Douglas I. Lin, Julia A. Elvin, Garrett M. Frampton, James J. Pao. Investigating digital pathology tumor microenvironment features for immunotherapy outcome in patients with advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4969.

Effects of CTLA-4 Single Nucleotide Polymorphisms on Toxicity of Ipilimumab-Containing Regimens in Patients With Advanced Stage Melanoma.

Single nucleotide polymorphisms (SNPs) in the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) gene, an inhibitor of T-cell priming, are associated with auto and alloimmunity. Studies implied a role for these SNPs as surrogate markers for immunotherapy-outcome in patients with melanoma. However, no predictive SNPs are defined to date. We analyzed different CTLA-4 SNPs in a large multicenter cohort of patients with ipilimumab-treated melanoma and investigated possible correlations with treatment-related outcomes. Archival blood and/or tumor tissue samples were collected from 361 patients with advanced-stage ipilimumab-treated (±nivolumab) in 6 Swiss and Dutch hospitals. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry based DNA genotyping was performed for 10 different CTLA-4 SNPs: 49A>G, CT60G>A, Jo27T>C, Jo30G>A, Jo31G>T, -658C>T, -1722T>C, -1661A>G, 318C>T, and C>T rs1863800. Associations between different allele genotypes and occurrence of grade ≥3 adverse events (AEs) and survival were tested using univariable logistic regressions or Cox proportional hazard models. 262/361 (73%) patients could be analyzed; 65% of those were males, the median age was 58 years, 39% showed a partial or complete response, and 65% had ≥1 AEs. A TT-genotype of -1722T>C SNP was significantly associated with a lower incidence of grade ≥3 AEs (P = 0.049), whereas the GG-genotype of CT60G>A correlated with a higher incidence of grade ≥3 AEs (P = 0.026). The TT-genotype of Jo27T>C SNP (P = 0.056) and GG-genotype of Jo31G>T (P = 0.046) were associated with overall survival. CTLA-4 SNPs might predict treatment-related outcomes in patients with melanoma receiving ipilimumab. Confirmatory studies are needed to fully exploit those findings as predictive biomarkers for ipilimumab AEs.

Abstract A031: Biotherapeutic strategies targeting the CXCR2 axis for depletion of myeloid-derived suppressor cells in pancreatic ductal adenocarcinoma

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) has a 5-year survival rate of only 10%, and limited treatment options exist. Immune checkpoint inhibitors are effective in a variety of cancer types; however, the complex immunosuppressive tumor microenvironment (TME) of PDAC is a significant barrier to immunotherapy. Myeloid-derived suppressor cells (MDSCs) are abundant in PDAC tumors from humans and mouse models. MDSCs suppress effector T cell function and promote the expansion of other immunosuppressive cell types. This led us to hypothesize that targeting tumor MDSCs would be an effective therapeutic strategy for PDAC and enhance the efficacy of T cell based immunotherapy. Our preliminary data and the work from others shows that CXCR2 ligands such as CXCL8/IL-8, CXCL5/ENA78, and CXCL1/GROα are the most abundant soluble factors secreted by PDAC cells. CXCR2 ligands are critical for the homing of myeloid cells to sites of injury in cutaneous wound healing, suggesting that dysregulated secretion of CXCR2 chemokines in PDAC may mimic a wound healing response that attracts myeloid cells and promotes the expansion of MDSCs and an immunosuppressive TME. To test this hypothesis, we have designed and produced multiple drug-conjugated CXCR2 ligand-based engineered proteins to target and eliminate MDSCs from PDAC tumors. We are referring to these novel biotherapeutic molecules as Ligand Drug Conjugates (LDCs). We have demonstrated binding, internalization, induction of signaling, and cytotoxicity of these LDCs to CXCR2 expressing myeloid cells. Our data suggests that our engineered proteins are superior binders and activators of CXCR2 axis signaling compared to WT CXCR2 ligands. Utilizing CXCR2 knockin models we demonstrated that the cytotoxicity of our LDCs is CXCR2 dependent. In vivo, we are utilizing the KPC (LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre) mouse model of PDAC, which we've shown in preliminary studies to, like human PDAC, support an abundance of MDSCs in tumors as well as secondary lymphoid organs such as the spleen. We anticipate that this study will demonstrate the therapeutic potential and actionability of targeting MDSCs and will provide novel biotherapeutic drug candidates that will ultimately improve immunotherapy outcomes in patients with PDAC. Citation Format: Benjamin N. Christopher, Lety Reyes, Reeder Robinson, Lena Golick, Nathan Dolloff. Biotherapeutic strategies targeting the CXCR2 axis for depletion of myeloid-derived suppressor cells in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A031.

The impact of oncogenic driver mutations on neoadjuvant immunotherapy outcomes in patients with resectable non-small cell lung cancer.

Neoadjuvant immunotherapy has been demonstrated to be effective and safe in resectable non-small cell lung cancer (NSCLC) patients. However, the presence of different oncogenic driver mutations may affect the tumor microenvironment and consequently influence the clinical benefit from immunotherapy. This retrospective study included consecutive NSCLC patients (stage IIA to IIIB) who underwent radical surgery after receiving neoadjuvant immunotherapy at a single high-volume center between December 2019 and August 2022. Pathological response and long-term outcomes were compared based on the driver oncogene status, and RNA sequencing analysis was conducted to investigate the transcriptomic characteristics before and after treatment. Of the 167 patients included in this study, 47 had oncogenic driver mutations. KRAS driver mutations were identified in 28 patients, representing 59.6% of oncogenic driver mutations. Of these, 17 patients had a major pathological response, which was significantly higher than in the non-KRAS driver mutation group (60.7% vs. 31.6%, P = 0.049). Multivariate Cox regression analysis further revealed that the KRAS driver mutation group was an independent prognostic factor for prolonged disease-free survival (hazard ratio: 0.10, P = 0.032). The median proportion of CD8+ T cells was significantly higher in the KRAS driver mutation NSCLCs than in the non-driver mutation group (18% vs. 13%, P = 0.030). Furthermore, immune-related pathways were enriched in the KRAS driver mutation NSCLCs and activated after immunotherapy. Our study suggests that NSCLC patients with KRAS driver mutations have a superior response to neoadjuvant immunotherapy, possibly due to their higher immunogenicity. The findings highlight the importance of considering oncogenic driver mutations in selecting neoadjuvant treatment strategies for NSCLC patients.

Non-invasive CT imaging biomarker to predict immunotherapy response in gastric cancer: a multicenter study

BackgroundDespite remarkable benefits have been provided by immune checkpoint inhibitors in gastric cancer (GC), predictions of treatment response and prognosis remain unsatisfactory, making identifying biomarkers desirable. The aim of this...

Impact of BMI on immunotherapy outcomes in patients with advanced or recurrent endometrial cancer (1316)

Impact of BMI on immunotherapy outcomes in patients with advanced or recurrent endometrial cancer (1316)

The role of TOP2A in immunotherapy and vasculogenic mimicry in non-small cell lung cancer and its potential mechanism

Type IIA topoisomerase (TOP2A) is significantly associated with malignant tumor development, invasion, treatment and its prognosis, and has been shown to be a therapeutic target against cancer. In contrast, the role of TOP2A in the immunotherapy of non-small cell lung cancer as well as in Vasculogenic mimicry (VM) formation and its potential mechanisms are unclear. The aim of this study was to investigate the role of TOP2A in proliferation, skeleton regulation, motility and VM production in non-small cell lung cancer and its mechanisms by using bioinformatics tools and molecular biology experiments. Subgroup analysis showed that the low-risk group had a better prognosis, while the high-risk group was positively correlated with high tumor mutational load, M1-type macrophage infiltration, immune checkpoint molecule expression, and immunotherapy efficacy. As confirmed by further clinical specimens, the presence of TOP2A and VM was significantly and positively correlated with poor prognosis. Our study established a model based on significant co-expression of TOP2A genes, which significantly correlated with mutational load and immunotherapy outcomes in patients with non-small cell lung cancer. Further mechanistic exploration suggests that TOP2A plays an important role in immunotherapy and VM formation in NSCLC through upregulation of Wnt3a and PD-L1 expression.

A gut microbiota rheostat to forecast response to PDL1-VEGF blockade in mesothelioma.

e20534 Background: Targeting of the immune inhibitory PD1-PDL1 axis has proven clinically effective in mesothelioma, despite a low somatic mutation burden, and high rate of CDKN2A deletion. Tumour responses to anti PD1 or PDL1 immune checkpoint inhibition are heterogeneous, and the factors underpinning sensitivity remain poorly understood. We therefore addressed this knowledge gap through multi-omic interrogation of tumours from patients enrolled into arm 4 of the Mesothelioma Stratified Therapy umbrella trial (NCT03654833, MiST4), a multi-centre single arm phase IIA trial of atezolizumab and bevacizumab in patients with relapsed mesothelioma. Methods: Next generation sequencing of whole exomes (mesotheliomas and matched germline DNA), transcriptomes, and 16sRNA to profile gut microbiota were undertaken. Spatial phenotyping of the immune landscape employed multiplex immunofluorescence analysis using a 19x depth 4 panel detection. Tumour proportion score (TPS) for PDL1 was assessed using the 22C3 clone, and BAP1, p16ink4a assessed by immunohistochemistry. The MIST4 cohort was dichotomised by best tumour response (50:50) into those patients exhibiting any tumour reduction (R) versus those without (NR). Machine learning (boosting and bagging) was employed to decipher correlates of response. Results: Tumour responses correlated with progression-free survival (PFS, p = 0.0003). Neither PDL1 TPS or CDKN2A expression were predictive. The NR group exhibited a greater degree of genomic instability with higher somatic copy number burden (p = 0.02), homologous recombination deficiency (HRD, p = 0.03), and uniparental disomy (UPD, p = 0.01). Notably the burden of nonsynonymous mutations and neoantigens did not differ significantly between groups. The NR group was transcriptionally enriched for epithelial mesenchymal transition (p < 0.05). Conversely, 16s RNA sequencing revealed higher gut microbial diversity in the R group compared with NR (Shannon index p = 0.009) with R-group enrichment of the type 2 enterotype (provotella 33% vs 9%). R-group enriched genera comprised prevotella, butyricicoccus, bilophilla, Eubacterium ventriosum, whereas the NR group was enriched for erysipelatoclostidium. The log ratio of genera, ie. Log[GR/GNR] was 2-log higher for the R group (p < 0.0001) vs NR group, and was highly predictive of response (with an area under the receiver operator curve of 0.99). Log[GR/GNR] positively correlated with tumour CD8 T cell infiltration (r = 0.6, p = 0.05) and PFS (p = 0.04), but negatively with CD68 monocyte infiltration (p = 0.05), UPD (p = 0.008) and HRD (p = 0.05). Conclusions: We propose a model in which interacting tumour intrinsic and extrinsic factors correlate with response to PDL1-VEGF inhibition in patients with mesothelioma. Gut microbiota composition represents a new, potentially modifiable target with potential to improve immunotherapy outcomes in patients with mesothelioma. Clinical trial information: NCT03654833 .

Comprehensive genomic and immunohistochemical profiles and outcomes of immunotherapy in patients with recurrent or advanced cervical cancer.

This study aimed to investigate genomic and immunohistochemical (IHC) profiles and immunotherapy outcomes in patients with cervical cancer. Patients with recurrent cervical cancer who underwent tumor next-generation sequencing (NGS) with the TruSight Oncology 500 panel at Yonsei Cancer Center between June 2019 and February 2022, were identified. Patients who received treatment with checkpoint inhibitors during the same period were also identified. Clinical information, including histology, stage, human papillomavirus (HPV) genotype, IHCs profile, and therapy outcome, was reviewed. We identified 115 patients treated for recurrent cervical cancer, including 74 patients who underwent tumor NGS. Most of these 74 patients were initially diagnosed with advanced stage (63.6%) and had squamous cell histology (52.7%), and high-risk HPV (76.9%). Based on IHC analysis, the programmed death-ligand 1 combined positive score (PD-L1 CPS) was higher in patients with squamous cell carcinoma (SCC) than in those with adeno or mucinous types (P=0.020). HER2 receptor expression of 2+ and 3+ were identified in 5 and 1 patients, respectively, and significantly varied based on histology (p=0.002). Among the 74 patients, single nucleotide variants (SNVs) and copy number variations (CNVs) were identified in 60 (81.1%) and 13 patients (17.6%), respectively. The most common SNVs were PIK3CA, TP53, STK11, FAT1, and FBXW7 mutations. Mutations in PIK3CA, with two hotspot mutations, were frequently observed in patients with SCC histology, whereas mutations in TP53 were frequently observed in patients with non-SCC histology. Additionally, variations in FAT1 were exclusively identified in patients with SCC histology. Mutations in homologous recombination repair-associated genes were identified in 18 patients (24.3%). The most frequent CNV alteration was CCNE1 amplification. Moreover, among the 36 patients who underwent NGS and received immunotherapy, the tumor mutational burden and microsatellite instability were significantly correlated with immunotherapy duration. During this timeframe, 73 patients received pembrolizumab monotherapy, among whom a small portion showed a durable response. Comprehensive genomic and IHC profiling may help identify potential candidates for targeted immunotherapy in patients with cervical cancer.

CD71+ erythroid cells suppress T-cell effector functions and predict immunotherapy outcomes in patients with virus-associated solid tumors

BackgroundImmune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer. However, only a portion of patients respond to such treatments. Therefore, it remains a prevailing clinical need to identify factors...

Construction and validation of chemoresistance-associated tumor- infiltrating exhausted-like CD8+ T cell signature in breast cancer: cr-TILCD8TSig.

Accumulating evidence has revealed that CD8+ T cell exhaustion (Tex) results in worse immunotherapy outcomes. However, the molecular functions and mechanisms of action of Tex in chemoresistance needed to be elucidated. The populations of tumor-infiltrating CD8+ T cells (TILCD8Ts) in chemoresistant and chemosensitive groups of the GSE25066 dataset were calculated using CIBERSORT. Differentially expressed genes (DEGs) between TILCD8Ts and other immune cells were explored by integrating 16 immune cell datasets downloaded from the gene expression omnibus (GEO) database. Gene ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, univariate and multivariate Cox regression, and least absolute shrinkage and selection operator (LASSO) regression of TILCD8T-specific upregulated genes were used to construct a chemoresistant TILCD8T signature (cr-TILCD8TSig). Clinical prognostic data, genomic alterations, chemotherapy response, and immunotherapy response were compared between the different cr-TILCD8TSig subgroups in the GSE25066 and the cancer genome atlas breast cancer (TCGA-BRCA) cohorts. A cr-TILCD8TSig with exhausted features was identified, consisting of seven genes (TCF7, RARRES3, ARL4C, ITK, CDH3, GZMB, and KLRD1), which were identified from 104 TILCD8Ts-specific DEGs. Our results showed that compared to the cr-TILCD8TSig-low subgroup, the -high subgroup had a poorer distant relapse-free survival (DRFS) in the GSE25066 cohort and worse progression-free survival (PFS) in the TCGA-BRCA cohort. Univariate and multivariate Cox regression analyses also demonstrated that cr-TILCD8TSig was an independent prognostic factor in the two independent cohorts. Furthermore, cr-TILCD8TSig-low patients benefited more from chemotherapy and immunotherapy than cr-TILCD8TSig-high patients. Besides, we found cell transmembrane signal transduction and the ECM may provide the molecular basis for resistance to antitumor agents in the cr-TILCD8Sig-high subgroup. For genomic alterations, we revealed that mutations in PIK3CA, DMD, and APOB were more common in the cr-TILCD8Sig-high subgroup than in the cr-TILCD8Sig-low subgroup. A nomogram was finally constructed with good discrimination and calibration. cr-TILCD8TSig is a useful tool to independently predict prognosis, chemotherapy response, and immunotherapy outcomes in patients with breast cancer.

ETCTN 10476: A randomized phase 2 study of combination atezolizumab and varlilumab (CDX-1127) with or without addition of cobimetinib in previously treated unresectable biliary tract cancer.

TPS639 Background: The combination of the MEK inhibitor, Cobimetinib, with the PD-L1 antagonist, Atezolizumab, significantly improved progression-free survival (PFS) compared to Atezolizumab monotherapy in patients with advanced biliary tract cancer (BTC) following first-line chemotherapy (NCT03201458). Interrogation of biospecimens from this trial and parallel pre-clinical work showed that the addition of MEK inhibition enhanced tumor immunogenicity but simultaneously had detrimental effects on host T-cell activation and priming. The addition of immune co-stimulants rescues T-cell function in the setting of systemic MEK inhibition in vivo. Unlike other immune co-stimulatory markers, CD27 is one of the most positively differentially expressed receptors in the TME post-treatment with combined MEK inhibition and PD-L1 blockade. We hypothesize that addition of CD27 immune agonism to the combination of PD-L1 and MEK inhibition can improve immunotherapy outcomes in patients with BTC. Methods: We are conducting an open-label, randomized ph 2 trial evaluating a PD-L1 inhibitor (atezolizumab) in combination with a CD27 immune agonist (CDX-1127 [Varlilumab]) with or without addition of a MEK inhibitor (Cobimetinib) in patients with unresectable, previously treated, BTC. Key inclusion criteria include: adults with pathologically-confirmed BTC, s/p 1-2 lines of systemic therapy (including any FDA-approved targeted therapies) in the metastatic setting, measurable disease, ECOG performance status ≤1, adequate baseline organ and marrow function. Patients who have received gem-cis-durvalumab, and/or prior FGFR2/IDH1 targeted therapy are eligible for enrollment. The study is planned for 64 evaluable subjects (32 subjects per treatment arm) randomized in a 1:1 ratio, stratified by site of BTC location, to either Atezolizumab + CDX-1127 or Atezolizumab + CDX-1127 + Cobimetinib. During the 28-day treatment cycles, all patients receive Atezolizumab (840mg flat dose) and CDX-1127 (3mg/kg) infusions on D1 and D15. For those randomized to the triplet regimen arm, the additional Cobimetinib will be dosed orally at 60mg daily on days 1-21. Overall response rate and PFS are co-primary endpoints. A clinically meaningful improvement in ORR warranting further study is 20%. The primary correlative outcome is treatment-related changes in CD8+ infiltrating T cells. After an initial safety lead-in, a planned interim efficacy analysis will take place following enrollment of the first 18 patients in each treatment arm. Currently, 14 participants (n=6 [triplet arm], n=8 [doublet arm]), have been enrolled & treated on protocol. This study is sponsored by the NCI Cancer Therapy Evaluation Program and is open nationally at designated NCI Experimental Therapeutics Clinical Trials Network sites. Clinical trial information: NCT04941287 .

Abstract C035: Biotherapeutic strategies targeting the CXCR2 axis for depletion of myeloid-derived suppressor cells in pancreatic ductal adenocarcinoma

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) has a 5-year survival rate of only 10%, and limited treatment options exist. Immune checkpoint inhibitors are effective in a variety of cancer types; however, the complex immunosuppressive tumor microenvironment (TME) of PDAC is a significant barrier to immunotherapy. Myeloid-derived suppressor cells (MDSCs) are abundant in PDAC tumors from humans and mouse models. MDSCs suppress effector T cell function, leading us to hypothesize that targeting tumor MDSCs would be an effective therapeutic strategy for PDAC and enhance the efficacy of T cell-based immunotherapy. Our preliminary data and the work from others shows that CXCR2 ligands such as CXCL8/IL-8, CXCL5/ENA78, and CXCL1/GROα are the most abundant soluble factors secreted by PDAC cells. CXCR2 ligands are critical for the homing of myeloid cells to sites of injury in cutaneous wound healing, suggesting that dysregulated secretion of CXCR2 chemokines in PDAC may mimic a wound healing response that attracts myeloid cells and promotes the expansion of MDSCs and an immunosuppressive TME. To test this hypothesis, we have designed multiple biotherapeutic molecules that exploit CXCL5/ENA78 and CXCL1/GROa to target and eliminate MDSCs from PDAC tumors. Specifically, we have generated Pseudomonas aeruginosa exotoxin (ExoA) and IgG-Fc fusion proteins that will be used to deliver cytotoxic payloads to MDSCs. A variety of CXCR2 knockout and knock-in models will be used to demonstrate CXCR2 dependence and elimination of MDSCs in vitro. In vivo, we are utilizing the KPC (LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre) mouse model of PDAC, which we've shown in preliminary studies to, like human PDAC, support an abundance of MDSCs in tumors as well as secondary lymphoid organs such as the spleen. We anticipate that this study will demonstrate the therapeutic potential and actionability of targeting MDSCs and will provide novel biotherapeutic drug candidates that will ultimately improve immunotherapy outcomes in patients with PDAC. Citation Format: Ben N. Christopher, Reeder Robinson, Leticia Reyes, Lena Golick, Ashton Basar, Nathan Dolloff. Biotherapeutic strategies targeting the CXCR2 axis for depletion of myeloid-derived suppressor cells in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C035.

Predicting immunotherapy outcomes in patients with MSI tumors using NLR and CT global tumor volume.

Anti-PD-(L)1 treatment is indicated for patients with mismatch repair-deficient (MMRD) tumors, regardless of tumor origin. However, the response rate is highly heterogeneous across MMRD tumors. The objective of the study is to find a score that predicts anti-PD-(L)1 response in patients with MMRD tumors. Sixty-one patients with various origin of MMRD tumors and treated with anti-PD-(L)1 were retrospectively included in this study. An expert radiologist annotated all tumors present at the baseline and first evaluation CT-scans for all the patients by circumscribing them on their largest axial axis (single slice), allowing us to compute an approximation of their tumor volume. In total, 2120 lesions were annotated, which led to the computation of the total tumor volume for each patient. The RECIST sum of target lesions' diameters and neutrophile-to-lymphocyte (NLR) were also reported at both examinations. These parameters were determined at baseline and first evaluation and the variation between the first evaluation and baseline was calculated, to determine a comprehensive score for overall survival (OS) and progression-free survival (PFS). Total tumor volume at baseline was found to be significantly correlated to the OS (p-value: 0.005) and to the PFS (p-value:<0.001). The variation of the RECIST sum of target lesions' diameters, total tumor volume and NLR were found to be significantly associated to the OS (p-values:<0.001, 0.006,<0.001 respectively) and to the PFS (<0.001,<0.001, 0.007 respectively). The concordance score combining total tumor volume and NLR variation was better at stratifying patients compared to the tumor volume or NLR taken individually according to the OS (pairwise log-rank test p-values: 0.033,<0.001, 0.002) and PFS (pairwise log-rank test p-values: 0.041,<0.001, 0.003). Total tumor volume appears to be a prognostic biomarker of anti-PD-(L)1 response to immunotherapy in metastatic patients with MMRD tumors. Combining tumor volume and NLR with a simple concordance score stratifies patients well according to their survival and offers a good predictive measure of response to immunotherapy.

Combinatorial regimens of chemotherapeutic agents: A new perspective on raising the heat of the tumor immune microenvironment.

Harnessing the broad immunostimulatory capabilities of chemotherapy in combination with immune checkpoint inhibitors has improved immunotherapy outcomes in patients with cancer. Certain chemotherapeutic agents can extensively modify the tumor microenvironment (TME), resulting in the reprogramming of local immune responses. Although chemotherapeutic agents with an enhanced generation of potent anti-tumor immune responses have been tested in preclinical animal models and clinical trials, this strategy has not yet shown substantial therapeutic efficacy in selected difficult-to-treat cancer types. In addition, the efficacy of chemotherapeutic agent-based monotherapy in eliciting a long-term anti-tumor immune response is restricted by the immunosuppressive TME. To enhance the immunomodulatory effect of chemotherapy, researchers have made many attempts, mainly focusing on improving the targeted distribution of chemotherapeutic agents and designing combination therapies. Here, we focused on the mechanisms of the anti-tumor immune response to chemotherapeutic agents and enumerated the attempts to advance the use of chemo-immunotherapy. Furthermore, we have listed the important considerations in designing combinations of these drugs to maximize efficacy and improve treatment response rates in patients with cancer.

685P Genomic characteristics and immunotherapy outcomes in patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC)

Anti–PD1–based immune checkpoint blockade (ICB) treatment (Tx) is the standard therapy for R/M HNSCC but the objective response rate is low (<20%). Currently, PD-L1 expression is the only biomarker used in the clinic, however, the predictive value is low. The data on the correlation between ICB outcomes and genomic characteristics is scant. Here, we report a single institutional data of clinical outcomes and genomic characteristics of patients (pts) with R/M HNSCC treated with ICB-based therapy.

Gender matters. Sex-related differences in immunotherapy outcome in patients with non-small cell lung cancer.

Emerging evidence identified sex as a variable that can regulate immune system functions and modulate response to immunotherapy in cancer patients. This retrospective study analysed sex-related differences in immunotherapy outcome in a real-world population of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs). We retrospectively investigated clinical data of 99 patients with advanced NSCLC and treated with single agent nivolumab and pembrolizumab, at Medical Oncology Unit, Careggi University Hospital, Florence (Italy), between April 2014 to August 2019. Main clinical characteristics and clinical outcomes were analysed. Our study showed that efficacy of ICI treatment differed according to gender. A trend for better median progression free survival (mPFS) was reported in males (mPFS 5.0 months, 95% Confidence Interval [CI] 4.0-11.0) than females (mPFS 4.5 months, 95% CI 2.0-9.0) (p=0.133), while no significant difference for overall survival (OS) between the two sex groups was observed (p=0.622). In the nivolumab cohort we showed a statistically significant difference for a longer PFS in men compared to women (log-rank p=0.054), HR for PFS in females versus males was 1.81 (95% CI 0.97-3.37, p=0.062). Disease control rate (DCR) was achieved in 55.7% and 45.7% in men and women, respectively, while disease progression was registered in 44.3% of males and 54.3% of females (p=0.386). Gender is a variable that should be taken into account in the choice of immunotherapy. Future prospective randomized trials testing tailored sex-based immunotherapy strategies are required to validate our findings before integrating into clinical practice.

The Multi-Dimensional Biomarker Landscape in Cancer Immunotherapy.

The field of immuno-oncology is now at the forefront of cancer care and is rapidly evolving. The immune checkpoint blockade has been demonstrated to restore antitumor responses in several cancer types. However, durable responses can be observed only in a subset of patients, highlighting the importance of investigating the tumor microenvironment (TME) and cellular heterogeneity to define the phenotypes that contribute to resistance as opposed to those that confer susceptibility to immune surveillance and immunotherapy. In this review, we summarize how some of the most widely used conventional technologies and biomarkers may be useful for the purpose of predicting immunotherapy outcomes in patients, and discuss their shortcomings. We also provide an overview of how emerging single-cell spatial omics may be applied to further advance our understanding of the interactions within the TME, and how these technologies help to deliver important new insights into biomarker discovery to improve the prediction of patient response.