Therapeutic relevance of targeted sequencing in management of patients with advanced biliary tract cancer: DNA damage repair gene mutations as a predictive biomarker

536 Background: We conducted a trial to evaluate the efficacy and safety of SHR-1210 (a humanized anti-programmed cell death receptor 1 antibody) plus gemcitabine and oxaliplatin (GEMOX) as in untreated patients (pts) with biliary tract cancer (BTC) (NCT03486678). This study is to explore the predictive biomarkers for efficacy. Methods: Baseline lymphocyte count and lactate dehydrogenase (LDH) level were obtained from routine tests. Gene mutation and tumor mutation burden (TMB) from baseline tissue and blood samples were tested by the next generation sequencing (NGS) with a 425-gene panel. The expressions of PD-L1 and markers for lymphocyte, natural killer cells, and macrophages in baseline tumor tissue samples were analyzed by immunohistochemistry (IHC). Results: The median progression free survival (PFS) and overall survival (OS) in this trial was 6.2m and 12.1m, respectively. Firstly, pts with normal LDH level (≤271 U/L) had a tendency for longer PFS (6.2m vs 5.0m, p = 0.053) and significantly longer OS (p = 12.6m vs 6.8m, p < 0.001) than those with elevated LDH ( > 271 U/L). Low baseline lymphocyte count (≤ 1.1×109/L) was related to worse OS (12.6m vs 6.9m, p < 0.001) and PFS (6.2m vs 3.9m, p = 0.021). Secondly, baseline tissue and ctDNA gene mutations were detected in 33 and 30 pts, respectively. Tissue analysis showed that pts with STK11 (p = 0.0254), CTNNB1 (p < 0.001) and SMARCA4 (p = 0.0181) wild type showed significantly longer PFS than those with mutations. Pts with ARID1A gene wild type showed a tendency for longer PFS (p = 0.0634) and significantly longer OS (p = 0.0149). Gene mutations from baseline ctDNA revealed that pts with wild type SMARCA4, CTNNB1, STK11, and NF1 had longer PFS than those with mutations. Lastly, IHC meant that PD-L1 positivity may be related to longer PFS (TPS > 1%, p = 0.08; IPS > 1%, p = 0.05). Besides, pts with CD68+ HLA-DR+ macrophages > 0.01%, CD68+ HLA-DR- macrophages>2.5%, and CD56bright>1.7% and CD56dim > 0.05 also got PFS benefits (all p < 0.05). TMB (cutoff = 7 muts/mbp) was not associated with PFS. Conclusions: Despite limited sample size, biomarkers from routine blood test, gene mutation and immune microenvironment can be helpful to stratify pts who are sensitive to immunotherapy in advanced BTC. Clinical trial information: NCT03486678.

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Germline and Somatic DNA Damage Repair Gene Mutations and Overall Survival in Metastatic Pancreatic Adenocarcinoma Patients Treated with FOLFIRINOX

Clinical Cancer Research ◽

10.1158/1078-0432.ccr-18-1472 ◽

2018 ◽

Vol 24 (24) ◽

pp. 6204-6211 ◽

Cited By ~ 17

Author(s):

Amikar Sehdev ◽

Olumide Gbolahan ◽

Brad A. Hancock ◽

Melissa Stanley ◽

Safi Shahda ◽

...

Keyword(s):

Dna Damage ◽

Overall Survival ◽

Pancreatic Adenocarcinoma ◽

Dna Damage Repair ◽

Gene Mutations ◽

Repair Gene ◽

Damage Repair ◽

Metastatic Pancreatic Adenocarcinoma

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DNA-damage response-umbrella study of the combination of ceralasertib and olaparib, or ceralasertib and durvalumab in advanced biliary tract cancer: A phase 2 trial-in-progress.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.tps4166 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. TPS4166-TPS4166

Author(s):

Jee Sun Yoon ◽

Jin Won Kim ◽

Ji-Won Kim ◽

Tae-Yong Kim ◽

Ah-Rong Nam ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Biliary Tract ◽

Dna Damage Response ◽

Biliary Tract Cancer ◽

Phase 2 ◽

Dna Breaks ◽

Tumor Cell Death ◽

Tract Cancer ◽

Damage Response

TPS4166 Background: Ceralasertib (AZD6738) is a selective ATR inhibitor that causes stalled replication forks to collapse, leading to accumulation of double-strand DNA breaks, which is expected to have synergistic anti-tumor effects with immune checkpoint inhibitors (ICI) or PARP inhibitors. First, accumulation of DNA damage by ceralasertib induces tumor cell death, leads to the release of tumor-specific antigen, changing the tumor microenvironment to promote antigen presentation and enhances the anti-tumor effect of ICI. Second, by simultaneously inhibiting two DNA-damage response (DDR) pathways downstream of PARP and ATR, cancer cells are unable to repair damaged DNA, leading to cell death. Ceralasertib has demonstrated promising anti-tumor activity and manageable toxicity in combination with durvalumab or olaparib in solid tumors in a phase 1 study (NCT02264678). In preclinical studies, ceralasertib has shown potent anti-tumor effects in biliary tract cancer (BTC) as a monotherapy and in combination with chemotherapy (Nam, et al, 2019). Methods: This is an open-label, phase 2 umbrella study assessing the efficacy of ceralasertib in combination with durvalumab or olaparib in patients with advanced BTC. Eligible patients have histologically confirmed BTC (including intrahepatic or extrahepatic cholangiocarcinoma, gallbladder cancer, or ampullary cancer), have failed at least one chemotherapy and have ECOG performance status of 0-1. Patients who have received prior ICI, ATR or PARP inhibitor are excluded. Each cycle consists of 4 weeks. In ceralasertib /durvalumab cohort, 37 patients will receive durvalumab 1.5g on day 1 and ceralasertib 240mg twice daily on days 15-28. In ceralasertib /olaparib cohort, 37 patients receive ceralasertib 160mg once daily on days 1-7 and olaparib 300mg twice daily on days 1-28. The primary endpoint is disease control rate, with key secondary endpoints including overall response rate, progression-free survival, overall survival, and safety. Tissue and blood samples are being collected for translational biomarker studies. Clinical trial information: NCT04298021.

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