Outcomes Of Immune Checkpoint Inhibitors Research Articles

Abstract 4467: Plasmacytoid dendritic cells, prevalent in the TME of smokers, is associated with a good prognosis and treatment response of LUAD

Abstract Background: Attempts to find therapeutic biomarkers through investigation of subgroup showing good responses to certain drugs in cancer often yielded meaningful results. Smoker’s lung adenocarcinoma has consistently shown a favorable response to immune checkpoint inhibitors (ICIs) than non-smoker’s lung adenocarcinoma. Comparing the macrophages (Mϕ) and dendritic cells (DC) constituting the innate immune tumor microenvironment (TME) in lung cancer of smokers and nonsmokers, we tried to figure out the difference in TME and biomarkers that predict the therapeutic response to ICIs. Methods: The inflammatory TME of current and never smokers’ lung cancer was explored by tumor and adjacent normal appearing lung tissues (Tu and NL hereafter) scRNA sequencing and verified by IF, IHC, and open-source dataset. Results: Compared to lungs of nonsmokers, smokers’ lung have an increased proportion of cell populations involved in innate immunity, and the increased cell population was mostly Mϕ, which were enriched in NL. When the number of Mϕ present in the NL of the corresponding individual were taken as the denominator, Tu of smokers has a lower proportion of Mϕ than that of non-smokers. Further sub-clustering of Mϕ and DCs showed that FCN1-mono and CD163-LGMN Mϕ, which correspond to the initial differentiation into the resident cell population within the tissue, and mo-DC, cDC2, and pDC were significantly enriched in the Tu. Among them, pDC is a functionally differentiated tissue resident cell that showed a different tissue distribution pattern between smokers and non-smokers, so it was estimated as one of the causes of the different treatment response to ICIs between the two patient groups. The difference of pDC’s distribution was further verified through IHC staining using anti-LILRA4 and anti-TLR9 antibody, showing pDC was significantly enriched in the smokers’ TME. A significant increase in TLR9 expression was observed in or around lung cancer immediately after ionizing radiation or cisplatin treatment in LSL-Kras G12D mouse model. The survival analysis of TCGA-LUAD dataset showed that the patients' overexpressing pDC markers such as IRF4 and TLR9 was superior clinical outcomes to the age, gender and smoking matched control group. Comparing the difference in TMB between the top 25% and bottom 25% groups according to the expression of TLR9, it was 5.81/Mb in the upper group and 4.36/Mb in the subgroup, showing a significant difference. Conclusions: pDC is an innate immune cell population that showed a prominent increase in smokers’ TME compared to that of non-smokers, suggesting that its increase may be one the factors that smokers’ lung cancer show favorable responses to ICI than that of non-smokers. These findings suggest that the pDC signature can be developed as a biomarker predicting the response to ICIs and increasing the number of pDCs or its activity may improve treatment outcome of ICIs. Citation Format: Eun Young Kim, Yoon Jin Cha, Yong Jun Choi, Min Kyung Park, Yoon Soo Chang. Plasmacytoid dendritic cells, prevalent in the TME of smokers, is associated with a good prognosis and treatment response of LUAD. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4467.

Abstract 6270: Combination therapy with selective SMARCA2 (BRM) degraders for treatment of SMARCA4 (BRG1)-deficient cancers

Abstract SMARCA2 (BRM) and SMARCA4 (BRG1) are mutually exclusive core catalytic subunits of the SWI/SNF complexes and use their ATPase domain to regulate the composition of nucleosomes. Between 4-5% of Non-Small Cell Lung Cancer (NSCLC) patients harbor SMARCA4 damaging mutations or SMARCA4 homo-deletions, resulting in loss of SMARCA4 protein expression. These SMARCA4-deleted cancer cells are predicted to be highly dependent on the paralog gene SMARCA2 for their survival. Therefore, targeting SMARCA2 in SMARCA4-deleted cancers using selective SMARCA2 degraders induces synthetic lethality while sparing SMARCA4 wild type normal cells. Although the treatment of lung cancer has improved considerably in recent years with the development of immune checkpoint inhibitors (ICIs) and specific KRASG12C covalent inhibitors, KRASG12C mutations significantly co-occur in 15-17% of SMARCA4-deleted NSCLC patients and have also been shown to correlate with a worse clinical outcome. The co-occurrence of KRASG12C/SMARCA4-deletion mutations in NSCLC led us to investigate whether combining our selective SMARCA2 degraders with KRASG12C or other MAPK pathway inhibitors would demonstrate synergistic effects. To test this hypothesis, we treated SMARCA4 damaging/low expression KRASG12C mutant cell lines with our SMARCA2 degraders and several KRASG12C inhibitors, in addition to SHP2 and MEK inhibitors. Robust synergy was observed with these combinations, suggesting that targeting SMARCA2 together with agents that inhibit distinct nodes of the MAPK pathway in patients with SMARCA4-deleted cancer may be a promising therapeutic strategy. To further understand the mechanisms underpinning the synergy between our SMARCA2 degraders and KRASG12C/MAPK pathway inhibitors, we conducted RNA-seq and found unique transcriptional signatures in the synergistic combinations relative to those of either agent alone. We are currently testing if this in vitro synergy with our SMARCA2 degraders extends to in vivo combination efficacy in CDX and PDX models. Furthermore, early data suggested that SMARCA4 deletion may indicate poor outcomes of ICIs in lung cancer patients. Interestingly, our SMARCA2 degraders promote the antigen presentation pathway and induce pro-inflammatory cytokine expression in SMARCA4-deleted cancer cells. We are currently investigating combinations of our SMARCA2 degraders with ICIs using syngeneic mouse models and human ex-vivo approaches. In summary, our preclinical data suggest that potent and selective SMARCA2 targeted degraders may potentially improve patient outcomes when combined with therapeutic agents targeting the RAS/MAPK pathway and/or ICIs in SMARCA4-deleted cancers. The combination of SMARCA2 degraders with standard of care agents warrants further investigation as a potential novel, effective, and highly targeted combination approach. Citation Format: Michael Hulse, Margot Elkins, Jessica Burtell, Komali Vykuntam, Kris Vaddi, Andrew Combs, Koichi Ito, Peggy Scherle. Combination therapy with selective SMARCA2 (BRM) degraders for treatment of SMARCA4 (BRG1)-deficient cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6270.

Abstract 3463: Longitudinal microbiome-immune dynamics in melanoma patients treated with immune checkpoint inhibitor immunotherapy

Abstract Background: Immune checkpoint inhibitor (ICI) immunotherapies have revolutionized the treatment of melanoma, although drug resistance or concurrent immune-related adverse events (irAEs) still impact many patients. There is growing evidence that immunotherapy outcomes are influenced by the gut microbiome. This includes differential associations for key bacterial groups such as Bacteroidaceae and Ruminococacceae. However, how gut microbes interact with the immune system to influence the success of ICIs and/or the development of irAEs remains unclear. Methods: We longitudinally profiled the gut microbiome and circulating immune cell subsets in stage III melanoma patients from Australia and the Netherlands (n=126) treated on trial with combination anti-PD-1/anti-CTLA-4 immunotherapy in the neo-adjuvant setting (NCT02977052). Paired pre- and post-treatment (baseline/week 6) stool samples were analyzed using 16S rRNA gene sequencing (n=126) and matched PBMCs were comprehensively profiled using mass cytometry (n=71). Results: Treatment with anti-PD-1/anti-CTLA-4 immunotherapy was associated with an increase in the frequency (% total CD45+) of CD8+ effector memory T cells (Tem) (CD45RA- CCR7-) (P= 0.0096) and a reduction in regulatory T cells (Tregs) (CD25+FoxP3+) (P= 0.0029) between baseline and week 6. The reduction in Tregs was dominantly observed in responders (P= 0.0016) compared to non-responders (P= 0.9515). However, patients who developed severe irAEs were also particularly deficient in Tregs at week 6 compared to patients with no or mild toxicities (P= 0.0293). Notably, in patients where circulating Tregs were reduced, the degree of reduction in Tregs positively correlated with the baseline relative abundance of Bacteroides (P< 0.0001). Higher pre-treatment Bacteroides abundance was also linked to the development of more severe irAEs (P= 0.0472) and overall steroid use (P= 0.0345) prior to week 6. Thus, while Bacteriodes here is linked to a response-associated parameter (reduction in Tregs), it is also linked to severe, early irAEs. In contrast, a higher abundance of Ruminococcaceae was protective, and overall a greater proportion of patients with Ruminococcaceae dominated microbiomes were responders, highlighting a role for both bacterial groups in shaping ICI outcomes. Conclusions: While response to ICI therapy was associated with a decrease in circulating Tregs, excessive reduction in Tregs was observed in patients that develop severe irAEs. Together, this highlights the delicate balance between immune activation and regulation in facilitating anti-tumor immune responses whilst avoiding irAEs. Our data suggests that the gut microbiome may have a role in establishing immune tone prior to and during immunotherapy and may influence this “tipping point” and the risk of developing irAEs. Citation Format: Rebecca C. Simpson, Erin R. Shanahan, Marcel Batten, Ines P. Silva, Irene L. Reijers, Judith M. Versluis, Alexander M. Menzies, Maria Gonzalez, Umaimainthan Palendira, Andrew Holmes, James S. Wilmott, Christian U. Blank, Richard A. Scolyer, Georgina V. Long. Longitudinal microbiome-immune dynamics in melanoma patients treated with immune checkpoint inhibitor immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3463.

Biomarkers predicting clinical outcomes in nasopharyngeal cancer patients receiving immune checkpoint inhibitors: A systematic review and meta-analysis.

Optimal biomarkers to select patients who will benefit most from immunotherapy remain lacking in nasopharyngeal cancer (NPC). This systematic review and meta-analysis aimed to evaluate the association between various biomarkers and clinical outcomes in NPC patients treated with immune checkpoint inhibitors (ICIs). Systematic searches of PubMed, Embase, Cochrane Library, and Web of Science databases were performed up to October 2022. Studies evaluating the association between biomarkers and intended outcomes of ICIs were included. The pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CIs) were calculated, respectively, for the objective response rate (ORR) and progression-free survival (PFS) under fixed or random-effect models. A total of 15 studies involving 1,407 patients were included. The pooled analysis indicated that NPC patients with lower plasma Epstein-Barr virus (EBV) DNA level at baseline (OR = 2.14, 95% CI: 1.46-3.14, P < 0.001), decreased EBV DNA load during immunotherapy (OR = 4.57, 95% CI: 2.24-9.34, P = 0.002) and higher programmed cell death-ligand 1 (PD-L1) expression (OR = 2.35, 95% CI: 1.36-4.09, P = 0.002) had superior ORR than the counterparts. No significant differences of ORR were observed between positive PD-L1 expression and negative PD-L1 expression (OR = 1.50, 95% CI: 0.92-2.45, P = 0.104), as well as higher tumor mutation burden (TMB) and lower TMB (OR = 1.62, 95% CI: 0.41-6.44, P = 0.494). Patients with lower plasma EBV DNA level at baseline obtained a significant benefit on PFS than those with higher plasma EBV DNA level (HR = 0.52, 95% CI: 0.42-0.63, P < 0.001). There were no differences in PFS between decreased EBV DNA load and increased EBV DNA load during immunotherapy (HR = 0.51, 95% CI: 0.22-1.17, P = 0.109), higher PD-L1 expression and lower PD-L1 expression (HR = 0.65, 95% CI: 0.42-1.01, P = 0.054), positive PD-L1 expression and negative PD-L1 expression (HR = 0.90, 95% CI: 0.64-1.26, P = 0.531), lower TMB and higher TMB (HR = 0.84, 95% CI: 0.51-1.38, P = 0.684). Lower baseline plasma EBV DNA level, decreased plasma EBV DNA during immunotherapy, and higher PD-L1 expression are reliable biomarkers predicting better response to ICIs treatment. Lower baseline plasma EBV DNA level was also associated with longer PFS. It is warranted to further explore and better illuminate the utility of these biomarkers in future clinical trials and real-world practice. https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022324434.

Clinical outcomes of immune checkpoint inhibitors in unresectable or metastatic combined hepatocellular-cholangiocarcinoma.

Immune checkpoint inhibitors (ICIs) have been demonstrated to be effective for unresectable or metastatic hepatocellular carcinoma (HCC) or cholangiocarcinoma (CCA) in prior prospective trials. However, the clinical outcomes of ICIs in patients with combined HCC-CCA (cHCC-CCA) have not been investigated. Accordingly, we retrospectively evaluated the effectiveness and safety of ICIs in patients with unresectable or metastatic cHCC-CCA. Among 101 patients with histologically documented cHCC-CCA who received systemic therapy, 25 received ICIs between January 2015 and September 2021 and were included in the current analysis. Overall response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were retrospectively evaluated. The median age was 64years (range 38-83) and 84% (n = 21) of patients were males. Most patients had Child-Pugh A liver function (n = 22, 88%) and hepatitis B virus infection (17, 68%). Nivolumab (n = 17, 68%) was the most frequently used ICI, followed by pembrolizumab (n = 5, 20%), atezolizumab plus bevacizumab (n = 2, 8%), and ipilimumab plus nivolumab (n = 1, 4%). All patients, except one, had previously received systemic therapy; median two lines (1-5 lines) of systemic therapy were administered prior to ICIs. With a median follow-up duration of 20.1months (95% CI 4.9-35.2months), the median PFS was 3.5months (95% CI 2.4-4.8months), and the median OS was 8.3months (95% CI 6.8-9.8months). The ORR was 20.0% (n = 5, nivolumab for 2 patients, pembrolizumab for 1, atezolizumab plus bevacizumab for 1, and ipilimumab plusnivolumab for 1) and the duration of response was 11.6months (95% CI 11.2-12.0months). ICIs displayed clinical anti-cancer effectiveness, aligning with the results of prior prospective studies for HCC or CCA. Further international studies are required to define the optimal strategies for managing unresectable or metastatic cHCC-CCA.

Roles and therapeutic implications of m6A modification in cancer immunotherapy.

Recent studies have demonstrated that N6-methyladenosine (m6A), the most abundant, dynamic, and reversible epigenetic RNA modification in eukaryotes, is regulated by a series of enzymes, including methyltransferases (writers), demethylases (erasers), and m6A recognition proteins (readers). Aberrant regulation of m6A modification is pivotal for tumorigenesis, progression, invasion, metastasis, and apoptosis of malignant tumors. Immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, as recognized by the 2018 Nobel Prize in Medicine and Physiology. However, not all cancer patients response to ICI therapy, which is thought to be the result of intricate immune escape mechanisms. Recently, numerous studies have suggested a novel role for m6A epigenetic modification in the regulation of tumor immune evasion. Herein, we review the relevant mechanisms of m6A regulators in regulating various key signaling pathways in cancer biology and how m6A epigenetic modifications regulate the expression of immune checkpoints, opening a new window to understand the roles and mechanisms of m6A epigenetic modifications in regulating tumor immune evasion. In addition, we highlight the prospects and development directions of future combined immunotherapy strategies based on m6A modification targeting, providing directions for promoting the treatment outcomes of immune checkpoint inhibitors.

Disease Etiology and Outcomes After Atezolizumab Plus Bevacizumab in Hepatocellular Carcinoma: Post-Hoc Analysis of IMbrave150

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of hepatocellular carcinoma (HCC) by inducing meaningful rates of antitumor responses and having favorable toxicity profiles. Based on large, randomized phase III trials, including the IMbrave150 study testing atezolizumab plus bevacizumab vs sorafenib, combination ICI regimens have emerged as the preferred frontline treatments for HCC based on their overall survival (OS) benefit. 1 Finn R.S. et al. N Engl J Med. 2020; 382: 1894-1905 Crossref PubMed Scopus (2345) Google Scholar ,2 Abou-Alfa G.K. et al. N Engl J Med. 2022; 1 Google Scholar HCC biology may be influenced by distinct etiologies underlying tumorigenesis including viral infections, alcohol-related injury, and metabolic causes. Based on in vivo models and retrospective studies, nonalcoholic fatty liver disease (NAFLD)-related HCC is purported to be resistant to ICIs. 3 Pfister D. et al. Nature. 2021; 592: 450-456 Crossref PubMed Scopus (345) Google Scholar , 4 Heinrich B. et al. Gastroenterology. 2021; 160: 331-345 Abstract Full Text Full Text PDF PubMed Google Scholar , 5 Foerster F. et al. Hepatology. 2022; 75: 1604-1626 Crossref Scopus (21) Google Scholar , 6 Kelley R.K. et al. N Engl J Med. 2021; 385: 280-282 Crossref PubMed Scopus (0) Google Scholar , 7 Haber P.K. et al. Gastroenterology. 2021; 161: 879-898 Abstract Full Text Full Text PDF PubMed Google Scholar Despite their limitations, these lines of evidence have led to the prevailing notion that the underlying etiology of liver disease influences ICI outcomes in HCC, with NASH being a barrier to ICI benefits, although this finding remains controversial. 5 Foerster F. et al. Hepatology. 2022; 75: 1604-1626 Crossref Scopus (21) Google Scholar , 6 Kelley R.K. et al. N Engl J Med. 2021; 385: 280-282 Crossref PubMed Scopus (0) Google Scholar , 7 Haber P.K. et al. Gastroenterology. 2021; 161: 879-898 Abstract Full Text Full Text PDF PubMed Google Scholar , 8 Ho W.J. et al. J Immunother Cancer. 2020; 8 Google Scholar Herein, we performed a post-hoc patient-level analysis of the IMbrave150 trial to evaluate if cirrhosis etiology affects survival or antitumor responses after atezolizumab plus bevacizumab.

Pretreatment Hemoglobin Levels and Platelet-to-Lymphocyte Ratio Predict Survival Benefit from Pembrolizumab in Advanced Urothelial Carcinoma.

Several prognostic risk factors have been recognized when using cisplatin-based conventional chemotherapy for the treatment of advanced urothelial carcinoma (UC); these include performance status (PS), liver metastasis, hemoglobin (Hb) levels, time from prior chemotherapy (TFPC), and other systemic inflammation scores including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). However, the benefit of these indicators for predicting outcome of immune checkpoint inhibitors is not fully understood. Here, we investigated the predictive value of the indicators in patients who received pembrolizumab for the treatment of advanced UC. Seventy-five patients who received pembrolizumab treatment for advanced UC were included. The Karnofsky PS, liver metastasis, hemoglobin levels, TFPC, NLR, and PLR were analyzed, and their relationship with overall survival (OS) was determined. All factors were highlighted as significant prognostic indicators for OS in the univariate proportional regression analysis (p<0.05 for each). Multivariate analysis revealed that Karnofsky PS and liver metastasis were independent prognostic indicators for OS (p<0.01) but were applicable only for a small number of patients. Notably, the combined analysis with low Hb levels and high PLR was significantly associated with OS in patients who could gain less benefit from pembrolizumab at a median of 6.6 [95% confidence interval (CI)=4.2-9.0] versus 15.1 (95% CI=12.4-17.8) months (p=0.002). The combination of Hb levels and PLR may be a broadly applicable indicator for the outcome of pembrolizumab as second-line chemotherapy in patients with advanced UC.

Abstract PD4-05: PD4-05 Integrated multi-cohort profiling identifies CCL19+ dendritic cells to potentiate immunotherapy efficacy in triple-negative breast cancer

Abstract Background: Immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis have emerged as constituting a new pillar for breast cancer; however, they benefit only a subset of patients, and predictive biomarkers are urgently needed. While dendritic cells (DCs) are essential for the orchestration of antitumor immune response, the clinical value of DCs in breast cancer immunotherapy remains unclear. An improved understanding of the functional diversity of DC subsets, as well as their relationship with ICI response, would eventually improve the efficacy of ICIs in breast cancer patients. Objective: We sought to comprehensively characterize DC heterogeneity within the tumor microenvironment, identify distinct DC subsets associated with the response to ICIs, and define clinically applicable predictive biomarkers for ICI therapy. Methods: We performed a comprehensive single-cell RNA sequencing (scRNA-seq) analysis of 53 breast tumors receiving ICIs or chemotherapy in two retrospective studies (NCT03197389 and GSE169246) to identify specific DC populations associated with ICI responsiveness. Next, we harnessed multiplex immunohistochemistry (n = 186), multiparametric flow cytometry of fresh tissues (n = 87), large consecutive transcriptomic datasets (The Cancer Genome Atlas [TCGA] and Fudan University Shanghai Cancer Center [FUSCC]), and in vivo experiments to illustrate the molecular portraits and clinical relevance of the identified DC subsets. Additionally, except for the two scRNA-seq datasets, we leveraged another four independent cohorts (NCT03805399, NCT04613674, NCT04129996, GSE124821) and assessed the clinical utility of the established clinically applicable biomarkers derived from prior analyses to predict response following treatment with ICIs or chemotherapy. Results: By obtaining single-cell transcriptome data of 1,955 high-quality DCs, we identified five distinct DC subpopulations (CLEC9A+, CD1A+, CLEC10A+, CCL19+, and LILRA4+). We then illustrated that a specific CCL19+ DC population, but not whole DCs or other subsets, was associated with ICI responsiveness, particularly in triple-negative breast cancer (TNBC). Mechanistically, a potent CD8+ T-cell response was unleashed, rendering tumors susceptible to PD-1 blockade in vivo and confirming their putative immunomodulatory capacity. This phenomenon was only observed in CCL19+ DCs but not in CCL19- DCs, indicating CCL19 as a specific marker and could reflect the infiltration and functional phenotype of CCL19+ DCs in breast tumors. Finally, by integrating six independent ICI therapy cohorts, we demonstrated that baseline CCL19 in both tumor and blood could predict better response and survival in TNBC patients receiving ICIs, but not so for chemotherapy. Conclusions: Our results provide important insights into the relationship between the clinical outcome of ICIs and DC heterogeneity at single-cell resolution, support the development of therapies modulating CCL19+ DCs to trigger antitumor CD8+ T-cell immunity, and suggest baseline CCL19 levels as a noninvasive predictive biomarker for patients receiving ICIs, that are potentially applicable in the clinic. In light of these results, we suggest CCL19+ DC modulation as a possible precision immunotherapy approach for cancer patients. Citation Format: Song-Yang Wu, Si-Wei Zhang, Ding Ma, Xi Jin, Yi-Zhou Jiang, Zhi-Ming Shao. PD4-05 Integrated multi-cohort profiling identifies CCL19+ dendritic cells to potentiate immunotherapy efficacy in triple-negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD4-05.

Outcomes of immune checkpoint inhibitors for postoperative recurrence of non-small cell lung cancer.

Immune checkpoint inhibitors (ICIs) are effective treatment options for patients with advanced non-small cell lung cancer (NSCLC); however, there is a dearth of data on outcomes of patients receiving ICIs for postoperative recurrence. The objective of this study was to investigate the short- and long-term outcomes of patients who received ICIs for postoperative recurrence. A retrospective chart review was performed to identify consecutive patients who received ICIs for postoperative recurrence of NSCLC. We investigated therapeutic responses, adverse events, progression-free survival (PFS), and overall survival (OS). Survival outcomes were estimated using the Kaplan-Meier method. Univariable and multivariable analyses were performed using the Cox proportional hazards model. Eighty-seven patients, with a median age of 72years were identified between 2015 and 2022. The median follow-up period after ICI initiation was 13.1months. Adverse events of grade ≥ 3 were observed in 29 (33.3%) patients, including 17 (19.5%) patients with immune-related adverse events. The median PFS and OS of the whole cohort were 3.2 and 17.5months, respectively. Limited to those receiving ICIs as first-line therapy, the median PFS and OS were 6.3 and 25.0months, respectively. On multivariable analysis, smoking history (HR: 0.29, 95% CI 0.10-0.83) and non-squamous cell histology (HR: 0.25, 95% CI 0.11-0.57) were associated with more favorable PFS in patients receiving ICIs as first-line treatment. Outcomes in patients receiving ICIs as first-line treatment appear acceptable. A multi-institutional study is required to confirm our findings.

Association of biomarkers and response to immune checkpoint inhibitors (ICIs) in patients with metastatic urothelial carcinoma (mUC) with high and low tumor mutation burden (TMB).

534 Background: ICIs are frequently used as therapy in mUC, but only a minority of patients (pts) respond to treatment. High TMB is associated with improved outcomes to ICIs. However, much is unknown about biomarkers associated with ICI outcomes in pts with high and low TMB respectively. Methods: We retrospectively identified mUC pts with known TMB status and available next generation sequencing (NGS) results treated with ICI monotherapy at our institution. TMB high was defined as ≥ 10 mutations/Mb, with the rest being TMB low. Somatic alterations present in ≥10% pts ( ARID1A, CCND1, CDKN2A, CDKN2B, ERBB2, FGF3, FGF4, FGF19, FGFR3, KDM6A, MDM2, MLL2, PIK3CA, RB1, TERTp, TP53, TSC1), and presence of DNA damage response (DDR) alterations were assessed as biomarkers of interest. Within the TMB-high and TMB-low pt groups we separately assessed patients based on the presence or absence of these somatic alterations, APOBEC mutational signature and high PD-L1 expression. Log rank test was used to determine differences in overall survival (OS) and progression free survival (PFS) among these groups. P-value ≤0.05 was considered significant. Results: Among 107 mUC pts treated with ICI monotherapy between 12/2014 and 3/2022 who had NGS data (UCSF500, FoundationOne, Strata), 85 pts had TMB data, including 47 TMB high pts and 38 TMB low pts. Among 85 pts with known TMB status, median age was 76 yrs, the majority were male (55, 65%), Caucasian (57, 67%), had pure urothelial histology (46, 55%) and were treated with ICIs in frontline setting (47, 55%). Median OS was 17.2 mos and median PFS was 3.42 mos. In TMB high pts, presence of DDR , MLL2, KDM6A, PIK3CA and TERTp alterations were each associated with improved outcomes, while presence of CDKN2B alterations was associated with inferior outcomes (Table). Among TMB low pts, those with RB1 alterations had shorter mOS (11.3 months vs 17.2 months; p=0.04) compared to wild-type pts. Conclusions: In this single-center retrospective analysis of mUC pts, we identified somatic alterations that were predictive of outcomes with ICI treatment in TMB high and TMB low pts respectively. Further exploration of biomarkers in patients stratified by TMB status is warranted in larger cohorts. [Table: see text]

Does the time-of-day administration of immune checkpoint inhibitors affect efficacy in patients with metastatic renal cell carcinoma? A single-center study.

681 Background: Immune checkpoint inhibitors (ICI) are the standard of care for metastatic renal cell carcinoma (mRCC). Circadian rhythm drives organisms to properly predict and react to cyclical changes in the environment, and also affects the adaptive immune response. Here, we study the relationship between time-of-day ICI administration and outcomes in mRCC patients (pts). Methods: This is a single-center retrospective study of ICI-treated mRCC pts diagnosed from January 2014 to March 2022. Day and time of each ICI infusion (inf) for each pt were obtained from the pharmacy records. Proportion of ICI inf administered after 4:30 pm (ICI430) was calculated based on a prior publication (Quian, Lancet Oncol 2021). The primary outcome was overall survival (OS), and secondary endpoints were time on treatment (TOT), time to next treatment (TNT), and overall response rate (ORR). The proportion of ICI430 as a continuous variable, and the dichotomized data (≥20% and ≥50%) were correlated with OS, TOT and TNT by Kaplan-Meier analysis and Cox regression, and with ORR by logistic regression. Results: Overall, 104 pts and 1763 inf were analyzed (Table). 48 pts were treated with 1st line (1L) ICI. 903 inf were administered (median 12 inf per pt, 1 - 111), 146 (15.6%) after 4:30 pm. 12 (25%) and 2 (4.2%) pts received ≥ 20% and ≥ 50% ICI430. Due to the small number of events (5 deaths and 15 progressions), of ICI430, and heterogeneity of treatments in 1L, we focus on pts treated with 2nd line (2L) ICI. 56 pts were treated with ICI in ≥2L. 860 inf were administered (median 8 inf per pt, 1 - 123), 180 (20.9%) after 4:30 pm. 15 (34.1%) and 9 (20.5%) pts received ≥20% and ≥50% ICI430. Pts who received ≥20% after 4:30pm, received fewer inf (7 vs. 16, p=0.022), had a worse TOT (4.3 vs. 9 m, HR 2.5, p=0.013), a trend to a worse TNT (6.3 vs. 10.5 m, HR 1.9, p=0.06) and a worse OS (16.9 vs. 56.1 m, HR 3.1, p=0.01). Similar results were obtained when using ≥ 50% ICI430 as the cut-off (TOT, 2 vs. 9m, p=0.007; TNT 4.7 vs. 10.5m, p=0.05; OS 16.9 vs. 36.6m, p=0.1), as well as higher frequency of progressive disease (85.7 vs. 21.9%, p=0.006). A significant association with OS (HR 1.02, p=0.03) was shown when analyzing ICI430 as a continuous variable, meaning a 16% increase in the risk of death for each 10% increment of ICI inf after 4:30 pm. Conclusions: Administration of ≥2L ICI after 4:30 pm is associated with poor overall survival. Our results could have a direct impact on pt survival and organization of outpatient clinics, but further research is needed. [Table: see text]

Prognostic Value of the Lung Immune Prognosis Index Score for Patients Treated with Immune Checkpoint Inhibitors for Advanced or Metastatic Urinary Tract Carcinoma

Few prognostic factors have been identified in patients with metastatic urothelial carcinoma (mUC) treated with immune checkpoint inhibitors (ICIs). The Lung Immune Prognostic Index (LIPI) was associated with clinical outcomes for ICIs in several tumor types. We aim to assess the value of the LIPI in patients with mUC treated with ICIs. A retrospective ICI cohort and a validation cohort (SAUL cohort) included, respectively, patients with mUC treated with ICI in 8 European centers (any line) and patients treated with atezolizumab in a second or further line. A chemotherapy-only cohort was also analyzed. The LIPI score was based on 2 factors, derived neutrophils/(leukocytes minus neutrophils) ratio (dNLR) > 3 and lactate dehydrogenase > upper limit of normal, and defined 3 prognostic groups. The association of LIPI with progression-free survival (PFS) and overall survival (OS) was assessed. In the ICI and SAUL cohorts, 137 and 541 patients were respectively analyzed. In the ICI cohort, mPFS and mOS were 3.6 mo (95% CI; 2.6-6.0) and 13.8 mo (95% CI; 11.5-23.2) whereas in the SAUL cohort the mPFS and mOS were 2.2 mo (95% CI; 2.1-2.3) and 8.7 mo (95% CI; 7.8-9.9) respectively. The LIPI classified the population of these cohorts in good (56%; 52%), intermediate (35%; 36%) and poor (9%; 12%) prognostic groups (values for the ICI and SAUL cohorts respectively). Poor LIPI was associated with a poorer OS in both cohorts: hazard ratio (HR) for the ICI cohort = 2.69 (95% CI; 1.24-5.84, p = 0.035); HR = 2. 89 for the SAUL cohort (CI 95%: 1.93-4.32, p < 0.0001). Similar results were found in the chemo cohort. The LIPI score allows to identify different subgroups in patients with good prognostis according to the Bellmunt score criteria, with a subset of patients with poorer outcomes having an mOS of 3.7 mo compared to the good and intermediate LIPI subgroups with mOS of 17.9 and 7.4 mo, respectively. The LIPI score was associated with survival in mUC patients treated by ICIs. Future prospective studies will be required to test the combination of Bellmunt score and the LIPI score as a more accurate prognosis tool.

A mutational signature and significantly mutated driver genes associated with immune checkpoint inhibitor response across multiple cancers

Immune checkpoint inhibitor (ICI) treatments dramatically prolong the survival outcomes of several advanced cancers. However, as multiple studies reported, only a subset of patients could benefit from the ICI treatment. In this study, we aim to uncover novel molecular biomarkers predictive of immunotherapy efficacy across multiple cancers. Pre-treatment somatic mutational profiles and immunotherapy clinical information were obtained from 1097 samples of multiple cancers, including melanoma, non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (ccRCC), bladder carcinoma (BLCA), and head and neck squamous cell carcinoma (HNSCC). Mutational signatures, molecular subtypes, and significantly mutated genes (SMGs) were determined, and their connections with ICI response and outcome were also evaluated. We extracted a total of six mutational signatures across all samples. Among, a mutational signature featured by T > C substitutions was identified to associate with an ICI resistance. A molecular subtype determined based on mutational activities was connected with a significantly improved ICI response rate and outcome. Totaling 50 SMGs were identified, and we observed that patients with COL11A1 or COL4A6 mutations exhibited a superior ICI treatment efficacy than those without such mutations. In this study, we uncovered several novel molecular determinants of cancer immunotherapy response under a multiple-cancer setting, which provides clues for enrolling patients to receive immunotherapy and customizing personalized treatment strategies.

Retrospective analysis of drug intake affecting the intestinal microbiota and the therapeutic effects of chemotherapy on gastric cancer.

379 Background: Administration of some medications, such as antibiotics, antacids, and probiotic supplementation, may affects the treatment outcomes of immune checkpoint inhibitors (ICIs), through the change of gut microbiota in cancer patients. Even when ICIs are combined with cytotoxic chemotherapy (Chemo), a use of such medications is expected to be a potential biomarker. However, the impacts of medications that affect gut microbiota on the efficacy of Chemo alone is unclear. Methods: We retrospectively analyzed patients who received fluoropyrimidines and platinum-based therapy for advanced gastric cancer in our institutions between January 2010 and December 2019. Progression-free survival (PFS) and overall survival (OS) by history of antibiotic/antacid/probiotic supplementation, were analysed. Results: A total of 101 pts were analyzed. Median age was 66 years (range, 30-81), female/male; 36/65, 1st-line regimen SP/XP/SOX/XELOX/FOLFOX; 52/2/39/1/7. In all patients, The median PFS for first-line treatment was 5.8 months (95% CI: 5.0-7.3) and the median OS was 15.5 months (95% CI: 12.5-18.6).Univariate analysis for PFS of first-line treatment did not show a significant difference in antibiotic use (median 7.6 vs 5.5 months, HR: 0.79 [95%CI: 0.50-1.24], p=0.31), oral antacids (median 6.6 vs 5.8 months, HR: 0.96 [95%CI: 0.61-1.54], p=0.89) and probiotic supplementation (median 9.1 vs 5.5 months, HR: 0.7 [95%CI: 0.38-1.26], p=0.24). Similarly in OS, the use of antibiotics (median 18.4 versus 13.4 months, HR: 0.85 [95%CI: 0.53-1.37], p=0.49), oral antacids (median 16.3 vs 13.8 months, HR: 1.15 [95%CI: 0.70-1.88], p=0.58), and oral probiotic supplementation (median 20.2 vs 13.8 months, HR: 0.77 [95%CI: 0.42-1.40], p=0.40), with no statistically significant differences. Conclusions: In this study, there were no significant differences in PFS and OS between patients administered with or without antibiotics, antacids, or probiotic supplementation. Future studies are expected to investigate the impacts of these medications on the treatment outcomes of ICIs+Chemo combination.

Microsatellite instability (MSI), mismatch repair (MMR), and tumor mutational burden (TMB) as predictive biomarkers for immune checkpoint inhibitor (ICI) effectiveness in real-world patients with metastatic colorectal cancer (mCRC).

46 Background: The KEYNOTE-177 randomized controlled trial demonstrated that mCRC patients with MSI high (MSI-H) and/or deficient MMR (dMMR) have better outcomes on first-line ICI than chemotherapy. This study aimed to evaluate MSI by next-generation sequencing (NGS) as a predictive biomarker of ICI effectiveness in real-world settings, and compare MSI (NGS), dMMR (immunohistochemistry, IHC), and TMB (10 mut/Mb cutoff) in predicting ICI outcomes. Methods: A prospectively declared statistical analysis plan compared the effectiveness of first-line treatment ICI versus chemotherapy in patients with MSI-H mCRC, and compared the predictive power of ICI outcomes associated with biomarkers in any line of therapy (LOT). Patient data was obtained by the US-based de-identified Flatiron Health-Foundation Medicine real-world mCRC clinico-genomic database (FH-FMI CGDB), originating from ~280 US cancer clinics between Jan/2011 and Dec/2021. Differences in progression-free survival (PFS) and overall survival (OS) were evaluated by Cox proportional hazard models, adjusted for a risk score generated from prognostic clinical features. The likelihood ratio test evaluated the superiority of a biomarker in anticipating outcomes. Results: Patients with MSI-H mCRC had more favorable outcomes receiving first-line ICI (n=49) than chemotherapy (n=89) for PFS (median 24.87 vs. 5.65 months, hazard ratio (HR): 0.31, 95% confidence interval (CI) 0.18-0.52, p &lt;0.0001) and OS (median not reached (NR) vs. 24.1 months, HR: 0.45, 95% CI 0.23-0.88, p = 0.02). mCRC patients receiving ICI in any LOT (n=182) had favorable outcomes when MSI-H, dMMR, or TMB ≥10 (all p &lt;0.001). MSI (NGS) and MMR (IHC) were 90% concordant. MSI reclassified six cases that were proficient (p)MMR (all with TMB &gt;10, three with mutations in MMR genes, and 5 with BRAF mutation, consistent with MSI biology). When MSI (NGS) is added to dMMR (IHC) evaluation, there is an improvement in the prediction of TTNT (p = 0.0013), PFS (p = 0.0202), and OS (p = 0.0717), but adding MMR status to MSI did not improve explanatory power. Conclusions: MSI (NGS) robustly identifies mCRC patients with favorable outcomes on first-line ICI vs. chemotherapy, and is a nominally better predictor of ICI outcomes when compared with dMMR (IHC) alone. dMMR (IHC), MSI (NGS), and TMB have similar predictive power for ICI benefit. [Table: see text]

Implication of the Gut Microbiome and Microbial-Derived Metabolites in Immune-Related Adverse Events: Emergence of Novel Biomarkers for Cancer Immunotherapy.

Immune checkpoint inhibitors (ICIs) have changed how we think about tumor management. Combinations of anti-programmed death ligand-1 (PD-L1) immunotherapy have become the standard of care in many advanced-stage cancers, including as a first-line therapy. Aside from improved anti-tumor immunity, the mechanism of action of immune checkpoint inhibitors (ICIs) exposes a new toxicity profile known as immune-related adverse effects (irAEs). This novel toxicity can damage any organ, but the skin, digestive and endocrine systems are the most frequently afflicted. Most ICI-attributed toxicity symptoms are mild, but some are severe and necessitate multidisciplinary side effect management. Obtaining knowledge on the various forms of immune-related toxicities and swiftly changing treatment techniques to lower the probability of experiencing severe irAEs has become a priority in oncological care. In recent years, there has been a growing understanding of an intriguing link between the gut microbiome and ICI outcomes. Multiple studies have demonstrated a connection between microbial metagenomic and metatranscriptomic patterns and ICI efficacy in malignant melanoma, lung and colorectal cancer. The immunomodulatory effect of the gut microbiome can have a real effect on the biological background of irAEs as well. Furthermore, specific microbial signatures and metabolites might be associated with the onset and severity of toxicity symptoms. By identifying these biological factors, novel biomarkers can be used in clinical practice to predict and manage potential irAEs. This comprehensive review aims to summarize the clinical aspects and biological background of ICI-related irAEs and their potential association with the gut microbiome and metabolome. We aim to explore the current state of knowledge on the most important and reliable irAE-related biomarkers of microbial origin and discuss the intriguing connection between ICI efficacy and toxicity.

Comparative Effectiveness of Immune Checkpoint Inhibitors vs Chemotherapy in Patients With Metastatic Colorectal Cancer With Measures of Microsatellite Instability, Mismatch Repair, or Tumor Mutational Burden

The KEYNOTE-177 trial demonstrated that patients with metastatic colorectal cancer (MCRC) with high microsatellite instability (MSI-H) and/or mismatch repair deficiency (DMMR) have better outcomes when receiving first-line immune checkpoint inhibitors (ICIs) compared with chemotherapy. Data on performance of ICIs in patients with MCRC in standard practice settings remain limited, and direct MMR vs MSI outcome association comparisons are lacking. To validate MSI (determined by next-generation sequencing [NGS]) as a biomarker of ICI effectiveness among patients with MCRC in standard practice settings and examine the association of MSI assessed by NGS, DMMR by immunohistochemistry, and tumor mutational burden (cutoff, 10 mutations/megabase) with ICI outcomes. This comparative effectiveness research study of outcomes in prospectively defined biomarker subgroups used data from a deidentified clinicogenomic database and included patients who received Foundation Medicine testing (FoundationOne or FoundationOne CDx) during routine clinical care at approximately 280 US academic or community-based cancer clinics between March 2014 and December 2021. The population included 1 cohort of patients with MSI-H MCRC who received first-line ICIs or chemotherapy and a second cohort who received ICIs in any line of therapy (LOT) for biomarker examination. ICI therapy or chemotherapy assigned at physician discretion without randomization. The main outcomes were time to next treatment (TTNT), progression-free survival (PFS), and overall survival (OS). Hazard ratios were adjusted for known prognostic imbalances. Comparisons of explanatory power used the likelihood ratio test. A total of 138 patients (median age, 67.0 years [IQR, 56.2-74.0 years]; 73 [52.9%] female) with MSI-H MCRC received first-line ICIs or chemotherapy. A total of 182 patients (median age, 64.5 years [IQR, 55.2-72.0]; 98 [53.8%] female) received ICIs in any LOT. Patients receiving first-line ICIs vs chemotherapy had longer TTNT (median, not reached [NR] vs 7.23 months [IQR, 6.21-9.72 months]; adjusted hazard ratio [AHR], 0.17; 95% CI, 0.08-0.35; P < .001), PFS (median, 24.87 months [IQR, 19.10 months to NR] vs 5.65 months [IQR, 4.70-8.34 months]; AHR, 0.31; 95% CI, 0.18-0.52; P < .001), and OS (median, NR vs 24.1 months [IQR, 13.90 months to NR]; HR, 0.45; 95% CI, 0.23-0.88; P = .02). MSI added to DMMR better anticipated TTNT and PFS in patients receiving ICIs than DMMR alone. The same was not observed when DMMR evaluation was added to MSI. In this comparative effectiveness research study, MSI assessed by NGS robustly identified patients with favorable outcomes on first-line ICIs vs chemotherapy and appeared to better anticipate ICI outcomes compared with DMMR.

Tumor-infiltrating lymphocyte enrichment predicted by CT radiomics analysis is associated with clinical outcomes of non-small cell lung cancer patients receiving immune checkpoint inhibitors.

Enrichment of tumor-infiltrating lymphocytes (TIL) in the tumor microenvironment (TME) is a reliable biomarker of immune checkpoint inhibitors (ICI) in non-small cell lung cancer (NSCLC). Phenotyping through computed tomography (CT) radiomics has the overcome the limitations of tissue-based assessment, including for TIL analysis. Here, we assess TIL enrichment objectively using an artificial intelligence-powered TIL analysis in hematoxylin and eosin (H&E) image and analyze its association with quantitative radiomic features (RFs). Clinical significance of the selected RFs is then validated in the independent NSCLC patients who received ICI. In the training cohort containing both tumor tissue samples and corresponding CT images obtained within 1 month, we extracted 86 RFs from the CT images. The TIL enrichment score (TILes) was defined as the fraction of tissue area with high intra-tumoral or stromal TIL density divided by the whole TME area, as measured on an H&E slide. From the corresponding CT images, the least absolute shrinkage and selection operator model was then developed using features that were significantly associated with TIL enrichment. The CT model was applied to CT images from the validation cohort, which included NSCLC patients who received ICI monotherapy. A total of 220 NSCLC samples were included in the training cohort. After filtering the RFs, two features, gray level variance (coefficient 1.71 x 10-3) and large area low gray level emphasis (coefficient -2.48 x 10-5), were included in the model. The two features were both computed from the size-zone matrix, which has strength in reflecting intralesional texture heterogeneity. In the validation cohort, the patients with high predicted TILes (≥ median) had significantly prolonged progression-free survival compared to those with low predicted TILes (median 4.0 months [95% CI 2.2-5.7] versus 2.1 months [95% CI 1.6-3.1], p = 0.002). Patients who experienced a response to ICI or stable disease with ICI had higher predicted TILes compared with the patients who experienced progressive disease as the best response (p = 0.001, p = 0.036, respectively). Predicted TILes was significantly associated with progression-free survival independent of PD-L1 status. In this CT radiomics model, predicted TILes was significantly associated with ICI outcomes in NSCLC patients. Analyzing TME through radiomics may overcome the limitations of tissue-based analysis and assist clinical decisions regarding ICI.

Association of immune-related adverse events with the outcomes of immune checkpoint inhibitors in patients with dMMR/MSI-H metastatic colorectal cancer

BackgroundImmune checkpoint inhibitors (ICIs) show a tremendous activity in microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC), but a consistent fraction of patients does not respond. Prognostic/predictive markers are needed. Despite...