592 Background: Tumor-agnostic approvals of immune checkpoint inhibitors (ICI) include deficient mismatch repair/microsatellite instability high (dMMR/MSI-H) and high tumor mutational burden (TMB) while in cancer like metastatic gastroesophageal cancers, ICI use has been predicated on PD-L1 expression. ICI are increasingly used for metastatic HCC, but without required markers. We aimed to examine the genomic landscape of HCC in context of PD-L1 expression, and to determine clinical responses to ICI in this setting. Methods: Next-generation sequencing of DNA (592 or WES) and RNA (WTS) was tested at Caris Life Sciences (Phoenix, AZ). PD-L1 expression was tested by IHC (SP142) and compared as high (2+,5%), low (1-2,1%) and negative (0). dMMR/MSI-H was tested by IHC/NGS and TMB-High was defined as ³10 mutations/MB. QuantiSEQ was used to estimate the tumor microenvironment. X 2 /Fisher-Exact were used and significance was determined as P-value adjusted for multiple comparison ( Q < 0.05). Real-world overall survival (rwOS) was obtained from insurance claims and calculated from tissue collection to last contact; time-on-treatment (TOT) was calculated from start to finish of ICI treatments. Results: Overall, 17.7% of HCC expressed PD-L1 by IHC; 79/1306 (6.1%) had high expression. The overall prevalence of dMMR/MSI-H was 0.2%; TMB was high in 5.1%. PD-L1 expression was not associated with MSI-H or high TMB. When comparing tumors that are PD-L1 high vs. negative vs. low, expression of several immuno-oncologic (IO) markers LAG3 (median TPM: 2.4, 0.8, 0.5), CTLA-4 (2.9, 1.2, 0.5), IDO1 (4.2, 1.3, 0.6) and others, as well as T-cell inflamed and IFNg scores all decreased significantly with PD-L1 (all q<0.05), similar trends were seen with B cells, M1 macrophages, CD8+ T cells and T regs while opposite differences seen in NK cells (q<0.05). Additionally, when PDL1-high tumors were compared to PDL1-negative, mutations in CTNNB1 trended lower (21% vs 35%) while amplifications of KRAS (4% vs 0%), PDCD1LG2 (4% vs 0%) and mutations in HNF1A (3% vs 0%), HOXB13 (6% vs 0%), STK11 (5% vs 0%) trended higher; when PDL1-low were compared to PDL1-negative, mutations in TP53 (45% vs 32%), ELF3 (3% vs 0%), TSC2 (6% vs 2%) and PIK3CA (5% vs 1%) and amplifications in BCL9 (2% vs 0%) and CCNE1 (2% vs 0%) trended higher. When investigating clinical outcome of a cohort of 908 HCC tumors, PD-L1 expression had no effect on prognosis, and was not associated with differences in TOT of ICI in HCC. Conclusions: Prevalence of dMMR/MSI-H and TMB-H is very low in HCC. PD-L1 is only expressed in <20%. Even with a finding of strong association of expression of several established IO biomarkers with PD-L1 expression, it’s still not predictive of response to ICI. New biomarkers or molecular signatures need to be identified and validated to objectively identify HCC patients most likely to benefit from ICI treatment.
TPS581 Background: Biliary tract cancers (BTC) are a heterogeneous group of cancers affecting the epithelial lining of the intra- and extrahepatic portions of the biliary tree, ranking as the second most prevalent primary liver cancer after hepatocellular carcinoma. A subgroup of BTC was found to have an abundant tumor specific neoantigen expression, enriched expression of immune related genes and genes regulating inhibitory immune checkpoint proteins. Recent advancements in BTC treatment include the TOPZ-1 trial, which established the survival advantage of adding durvalumab to the gemzar + cisplatin regimen with an estimated 24-month overall survival rate of 24.9% versus 10.4% for placebo. The hazard ratio for progression-free survival favored durvalumab at 0.75 (95% CI, 0.63 to 0.89; P=0.001). Objective response rates also showed improvement, with 26.7% for durvalumab and 18.7% for placebo. Furthermore, single agent regorafenib has exhibited efficacy in patients with refractory advanced metastatic cholangiocarcinoma, particularly in terms of progression-free survival, favoring regorafenib over placebo, the overall toxicity profile was as expected. Regorafenib targets multiple tyrosine kinases and has been reported to show immunomodulatory properties that may counteract tumor-induced immunosuppression, providing a rationale for combining it with checkpoint inhibitors. We believe that modulating the tumor microenvironment with small molecule inhibitors like regorafenib will have synergistic effect when combined with checkpoint-based immunotherapy like durvalumab in patients with chemo refractory BTC. Methods: This study comprises a single-arm, unblinded Phase I/II trial designed to assess the safety and efficacy of the combination therapy involving regorafenib and durvalumab in patients with chemo-refractory advanced BTC. The Phase I portion employed a 3 + 3 design with two dose levels of regorafenib (80 mg and 120 mg) administered in conjunction with 1500 mg IV durvalumab every 28 days. Phase I successfully completed, and the Data Monitoring Committee (DMC) endorsed the continuation of the trial as planned. Eligibility: Histologically confirmed unresectable or metastatic disease. Progressed on at least one line of therapy. May have received checkpoint inhibitor in the past. Inclusion criteria also include ECOG PS 0-1. Objectives:Primary Phase I: Safety of regorafenib in combination with durvalumab.Phase II: Progression-free survival (PFS).Secondary:Disease Control Rate (DCR), Overall response rate (ORR), Overall survival (OS). Statistical Plan: Interim futility testing after one year, halting if conditional power < 20%. Final analysis: PFS and OS via Weibull Regression. Enrollment is currently ongoing with 8 out of 40 patients enrolled.
Colorectal cancer (CRC) is the third most common cancer in the United States. Recent epidemiological evidence demonstrates an increasing incidence of young-onset CRC cases, defined as CRC cases in individuals 50 years old or younger. Studies have established that alterations in both the WNT and TGF-Beta signaling pathways have contributed to CRC development. While this is well understood, the comprehensive analysis of WNT and TGF-Beta pathway alterations in young-onset CRC cases has yet to be investigated. Here, we conducted a comprehensive bioinformatics analysis of mutations associated with each of the WNT and TGF-Beta signaling pathways according to age (≤ 50 years old versus > 50 years old) utilizing published genomic data from the cBioPortal. Chi-square results demonstrated no significant difference in WNT alterations between young-onset CRC and those > 50 years old. However, across all age groups, WNT alterations were frequently found in rectal cancers. We also found that WNT alterations were associated with better outcomes. The mutations associated with TGF-beta were observed at a higher rate in older CRC patients when compared to those ≤ 50 years old. Additionally, these mutations were found more frequently in colon primaries.
Colorectal cancer treatment has evolved considerably in the last decade with the development of immunotherapies. Immune checkpoint inhibitor therapies have brisk and durable responses in patients with advanced microsatellite instability–high colorectal cancer, both surgically resectable and unresectable; however, patients with microsatellite stable colorectal cancer in general do not respond to the same therapy. Emerging evidence shows that immune checkpoint inhibitors may elicit responses in subsets of patients with microsatellite stable colorectal cancer, especially when combined with other anticancer agents that can modulate the tumor microenvironment. Therefore, rationally designed therapeutic combinations involving immune checkpoint inhibitors, as well as the development of predictive biomarkers for optimal patient selection, have emerged as two key areas of active research. In addition, other immunotherapeutic agents such as cell-based therapies and bispecific T-cell engagers are beginning to be studied in preclinical and early-phase settings. Although by no means a universal treatment strategy, immunotherapy can elicit responses in microsatellite stable colorectal cancer and further research is needed to extend their benefit to patients with microsatellite stable colorectal cancer. Here, we review the current state of immunotherapeutic regimens for microsatellite stable colorectal cancer.
The US Food and Drug Administration (FDA) approved pembrolizumab for patients with unresectable or metastatic solid tumors with tumor mutational burden (TMB) of ≥ 10 mutations/megabase. However, the clinical implications of this universal cutoff of TMB ≥ 10 for patients with microsatellite stable (MSS) metastatic colorectal cancer (CRC) remain debatable.In this review, we discuss the tissue agnostic approval of pembrolizumab, its efficacy, and clinical relevance in the management of patients with MSS CRC patients with high TMB (defined as TMB ≥ 10). We also elaborate on molecular subgroups of MSS CRC that influence the immune checkpoint inhibitor (ICI) response for patients with MSS CRC, including pathogenic POLE and POLD1 mutations associated with ultramutated tumors.Patients with microsatellite stable CRC with TMB ≥ 10 without POLE and POLD1 mutations may not significantly benefit from immune checkpoint inhibitors therapy. Predetermined cutoff TMB ≥ 10 mutation per MB does not seem to define a universal cutoff for the benefit of disease-agnostic ICI therapy, particularly for patients with MSS CRC. Patients with POLE/POLD1 mutations with MSS CRC represent a unique biological subgroup of MSS CRC with favorable responses to ICI therapy.
This report contains raw data related to article "Immunotherapy in Hepatocellular Cancer Patients with Mild to Severe Liver Dysfunction: Adjunctive Role of the ALBI Grade". Immune checkpoint inhibitors (ICI) have shown positive results in patients with hepatocellular carcinoma (HCC). As liver function contributes to prognosis, its precise assessment is necessary for the safe prescribing and clinical development of ICI in HCC. We tested the accuracy of the albumin-bilirubin (ALBI) grade as an alternative prognostic biomarker to the Child-Turcotte-Pugh (CTP). In a prospectively maintained multi-centre dataset of HCC patients, we assessed safety and efficacy of ICI across varying levels of liver dysfunction described by CTP (A to C) and ALBI grade and evaluated uni- and multi-variable predictors of overall (OS) and post-immunotherapy survival (PIOS). We studied 341 patients treated with programmed-death pathway inhibitors (n = 290, 85%). Pre-treatment ALBI independently predicted for OS, with median OS of 22.5, 9.6, and 4.6 months across grades (p < 0.001). ALBI was superior to CTP in predicting 90-days mortality with area under the curve values of 0.65 (95% CI 0.57-0.74) versus 0.63 (95% CI 0.54-0.72). ALBI grade at ICI cessation independently predicted for PIOS (p < 0.001). Following adjustment for ICI regimen, neither ALBI nor CTP predicted for overall response rates or treatment-emerging adverse events (p > 0.05). ALBI grade identifies a subset of patients with prolonged survival prior to and after ICI therapy, lending itself as an optimal stratifying biomarker to optimise sequencing of systemic therapies in advanced HCC.
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