Unresectable Biliary Tract Cancer Research Articles

Therapeutic Outcome of Multidisciplinary Treatment in Unresectable Biliary Tract Cancer: A Multicenter Retrospective Analysis.

There is little established evidence regarding treatment strategies for unresectable biliary tract cancer (BTC). This study aimed to clarify the situation of multidisciplinary treatment for unresectable BTC in the 2000s when there was no international standard first-line therapy. We retrospectively reviewed 315 consecutive patients with unresectable BTC who had been treated at seven tertiary institutions in Kanagawa Prefecture, Japan between 1999 and 2008. The unresectable factors were as follows: locally advanced, 101 cases (32.1%); hematogenous metastases, 80 cases (25.4%); and peritoneal dissemination, 30 cases (9.5%). Chemotherapy or radiation therapy was administered to 218 patients (69.2%). The best supportive care was provided in 97 cases (30.8%). The most common regimen was gemcitabine monotherapy, followed by gemcitabine combination therapy and S-1 monotherapy. The 1- and 2-year survival rates of all patients were 34.6% and 12.2%, respectively. The median survival time (MST) was 8 months in all patients. The 1-year survival rate was 65%, and the MST was 12 months among the locally advanced patients, whereas patients with peritoneal dissemination had the worst outcome; the 1-year survival rate was 7%, and the MST was 5 months. Among treated 90 cases of perihilar cholangiocarcinoma, patients who received chemoradiotherapy (n = 24) had a significantly better outcome than those who received chemotherapy alone (MST: 20 vs. 11 months, P < 0.001). Unresectable BTC has heterogeneous treatment outcomes depending on the mode of tumor extension and location. Multidisciplinary treatment seems useful for patients with locally advanced BTC, whereas patients with metastatic disease still have a poor prognosis.

Conversion surgery intervention versus continued systemic therapy in patients with a response after PD-1/PD-L1 inhibitor-based combination therapy for initially unresectable biliary tract cancer: a retrospective cohort study.

The role of conversion surgery in patients with unresectable biliary tract cancer (BTC) who responded positively to PD-1/PD-L1 inhibitor-based therapy remains unclear. This study aimed to assess the outcomes in patients with or without conversion surgery. In this cohort study, patients with advanced BTC who received combination therapy with PD-1/PD-L1 inhibitors from July 2019 to January 2023 were retrospectively. Patients who exhibited positive responses and met the criteria for conversion surgery were enrolled, and their surgical and oncological outcomes were analyzed. Out of 475 patients, 34 who met the conversion resection criteria were enrolled. The median follow-up was 40.5 months post-initiation of systemic therapy. Ultimately, 13 patients underwent conversion surgery, while 21 received continuation of systemic treatment alone (non-surgical group). The median interval from the initial antitumor therapy to surgery was 6.7 (interquartile range [IQR] 4.9-9.2) months. Survival with conversion surgery was significantly longer than the non-surgical cohort, with a median progression-free survival (PFS) (unreached vs. 12.4mo; hazard ratio 0.17 [95% CI 0.06-0.48]; P=0.001) and overall survival (OS) (unreached vs. 22.4mo; hazard ratio 0.28 [95% CI 0.09-0.84]; P=0.02), respectively. After a median postoperative follow-up of 32.2 months in the surgical cohort, 8 patients survived without recurrence. The estimated 3-year OS, PFS and recurrence-free survival rate in the surgical cohort were 59.9%, 59.2% and 60.6%, respectively. The R0 resection rate reached 92.3%, with 2 achieving a pathological complete response. One patient experienced a Clavien-Dindo grade 3 complication without surgery-related mortality. No serious adverse events or surgical delays were observed. Multivariate analysis indicated that conversion surgery was independently associated with OS (P=0.03) and PFS survival (P=0.003). Conversion surgery appears safe and offers survival benefits to patients responding to immune checkpoint inhibitors (ICIs)-based combinations. However, further studies are required to validate this strategy in the era of immunotherapy.

Durvalumab Plus Gemcitabine and Cisplatin Versus Gemcitabine and Cisplatin in Biliary Tract Cancer: a Real-World Retrospective, Multicenter Study.

The TOPAZ-1 phase III trial reported a survival benefit with the anti-programmed cell death ligand 1 (anti-PD-L1) durvalumab in combination with gemcitabine and cisplatin in patients with advanced biliary tract cancer (BTC). The present study investigated for the first time the impact on survival of adding durvalumab to cisplatin/gemcitabine compared with cisplatin/gemcitabine in a real-world setting. The analyzed population included patients with unresectable, locally advanced, or metastatic BTC treated with durvalumab in combination with cisplatin/gemcitabine or with cisplatin/gemcitabine alone. The impact of adding durvalumab to chemotherapy in terms of overall survival (OS) and progression free survival (PFS) was investigated with univariate and multivariate analysis. Overall, 563 patients were included in the analysis: 213 received cisplatin/gemcitabine alone, 350 received cisplatin/gemcitabine plus durvalumab. At the univariate analysis, the addition of durvalumab was found to have an impact on survival, with a median OS of 14.8 months versus 11.2 months [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.50-0.80, p = 0.0002] in patients who received cisplatin/gemcitabine plus durvalumab compared to those who received cisplatin/gemcitabine alone. At the univariate analysis for PFS, the addition of durvalumab to cisplatin/gemcitabine demonstrated a survival impact, with a median PFS of 8.3 months and 6.0 months (HR 0.57, 95% CI 0.47-0.70, p < 0.0001) in patients who received cisplatin/gemcitabine plus durvalumab and cisplatin/gemcitabine alone, respectively. The multivariate analysis confirmed that adding durvalumab to cisplatin/gemcitabine is an independent prognostic factor for OS and PFS, with patients > 70 years old and those affected by locally advanced disease experiencing the highest survival benefit. Finally, an exploratory analysis of prognostic factors was performed in the cohort of patients who received durvalumab: neutrophil-lymphocyte ratio (NLR) and disease stage were to be independent prognostic factors in terms of OS. The interaction test highlighted NLR ≤ 3, Eastern Cooperative Oncology Group Performance Status (ECOG PS) = 0, and locally advanced disease as positive predictive factors for OS on cisplatin/gemcitabine plus durvalumab. In line with the results of the TOPAZ-1 trial, adding durvalumab to cisplatin/gemcitabine has been confirmed to confer a survival benefit in terms of OS and PFS in a real-world setting of patients with advanced BTC.

Abstract 5132: Multi-omics analysis uncovers predictive biomarkers for the efficacy and outcomes of immune checkpoint inhibitor in combination with chemotherapy in advanced unresectable biliary tract cancers

Abstract Background: Biliary tract cancer, typically diagnosed at advanced stages with a poor prognosis, has witnessed a glimmer of hope in the progress of immune checkpoint inhibitors (ICIs). Yet, their limited response rates necessitate the search for effective biomarkers to refine patient selection. Methods: A total of 125 patients with a confirmed histological diagnosis of unresectable advanced or metastatic biliary tract cancers (BTC) who received first-line ICIs in combination with chemotherapy (chemoimmunotherapy) were prospectively enrolled. All baseline samples from 125 patients underwent targeted DNA sequencing, with an additional 62 patients undergoing RNA sequencing, and 85 patients had accessible mIHC data. The associations between molecular characteristics and the response to chemoimmunotherapy, progression-free survival (PFS) and overall survival (OS) were evaluated. Results: The cohort had a median age of 63 years (range from 34 to 82) and 52.8% (66/125) were male, including 54 with gallbladder cancer, 57 with intrahepatic cholangiocarcinoma, and 14 with extrahepatic cholangiocarcinoma. The median duration of follow-up was 14.8 months for the entire cohort, with the median PFS and OS of 6.9 months (95%CI: 6.2-7.9) and 11.8 months (95%CI: 10.3-14.8), respectively. The most mutated genes were TP53 (64/125, 51.2%), KRAS (34/125, 27.2%), ERBB2 (18/125, 14.4%), and ARID1A (17/125, 13.6%). Mutations of TP53 (51.2%, p = 0.042), BRCA2 (4.8%, p = 0.002), cytokine genes (6.4%, p = 0.004), and high tumor mutation burden (p = 0.072) demonstrated significant correlation with chemoimmunotherapy response. KRAS G12D mutations (PFS: P &amp;lt; 0.001; OS: P = 0.034) and ARID1A loss-of-function mutations (PFS: P = 0.009; OS: P = 0.012) were adverse survival factors, while high CXCL9 or CTLA4 expression was associated with response (CXCL9, P = 0.014; CTLA4, P = 0.067), improved PFS (CXCL9, P = 0.018; CTLA4, P = 0.008), and longer OS (CXCL9, P = 0.010; CTLA4, P = 0.008) under chemoimmunotherapy. Patients were classified into three subtypes using the identified survival biomarkers. Among them, Type I patients, characterized by the absence of KRAS G12D or ARID1A mutations but expressing high levels of CTLA4 or CXCL9, demonstrated the best outcomes under chemoimmunotherapy. Interestingly, further RNA analysis suggested that elevated CXCL9 expression correlated with heightened immune checkpoint expressions, including CTLA4, PD-L1, and PD-1 (all P &amp;lt; 0.001), as well as increased tumor microenvironment immune activity, findings validated in two additional independent patient cohorts both internal and external. Conclusions: Our study revealed predictive biomarkers relevant to the response and efficacy of immune checkpoint inhibitors in combination with chemotherapy in advanced biliary tract cancer. Citation Format: Jieer Ying, Qi Xu, Jiaojiao Ni, Hanlin Chen, Chaoqun Li, Yanru Xie, Qinhong Zheng, Jianying Jin, Junrong Yan, Xiaoying Wu, Qiuxiang Ou, Li Yuan, Wei Zhuo, Haimeng Tang. Multi-omics analysis uncovers predictive biomarkers for the efficacy and outcomes of immune checkpoint inhibitor in combination with chemotherapy in advanced unresectable biliary tract cancers [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 5132.

Analysis of the Clinical Course in a Population of Patients with Biliary Tract Cancer Diagnosed as Unresectable After Portal Vein Embolization: A Case Series.

Portal vein embolization (PVE) is recommended as a preoperative procedure for patients with biliary tract cancer scheduled to undergo hepatic resection of more than 50%-60% of the liver. However, details and/or information regarding the follow-up of unresectable cases are often lacking, and the clinical course of unresectable cases is not well analyzed and reported. This study aimed to clarify the clinical prognosis of patients with unresectable biliary tract cancer after PVE. We retrospectively analyzed the clinical backgrounds of patients with biliary tract cancer who underwent PVE without subsequent resection between January 2011 and October 2022. Of the 21 patients with biliary tract cancer who underwent PVE during the study period, eight (38%) cases were unsuitable for resection after PVE for the following reasons: intraoperatively detected dissemination (n=2), para-aortic lymph node metastasis (n=1), liver metastasis (n=1), decreased liver function (n=2), development of liver metastasis while waiting (n=1), and insufficient residual liver volume (n=1). All patients received subsequent chemotherapy, including gemcitabine plus S-1 therapy in three cases, gemcitabine plus cisplatin plus S-1 in three cases, and gemcitabine plus cisplatin or S-1+cisplatin in one case each. As there is currently no curative treatment for biliary tract cancer other than surgery, multidisciplinary management and treatment of patient factors, including tumor factors and liver function, are essential to reducing the number of unresectable cases after PVE.

Clinical outcomes for previously treated patients with advanced biliary tract cancer: a meta-analysis.

Aim: A systematic review and meta-analysis were performed to evaluate the efficacy of treatments for previously treated advanced biliary tract cancer (BTC) patients. Materials & methods: Databases were searched for studies evaluating treatments for advanced (unresectable and/or metastatic) BTC patients who progressed on prior therapy. Pooled estimates of objective response rate (ORR), median overall survival (OS)and median progression-free survival(PFS)were calculated using random effects meta-analysis. Results: Across 31 studies evaluating chemotherapy or targeted treatment regimens in an unselected advanced BTC patient population, pooled ORR was 6.9%, median OS was 6.6monthsand median PFS was 3.2months. Conclusion: The efficacy of conventional treatments for previously treated advanced BTC patients is poor and could be improved by novel therapies.

A phase 2, open-label, safety and efficacy study of telotristat ethyl plus first-line chemotherapy in patients with advanced biliary tract cancer.

472 Background: Patients (pts) with unresectable biliary tract cancer (BTC) have a poor prognosis. In preclinical models of cholangiocarcinoma (CCA) telotristat ethyl (TE), a tryptophan hydroxylase inhibitor that reduces production of serotonin, enhanced the antiproliferative effects of gemcitabine and cisplatin (GC) chemotherapy. This trial assessed the safety and efficacy of adding TE to GC chemotherapy in pts with advanced BTC. Methods: This was a Phase 2 open-label study. Eligible pts had unresectable, locally advanced, or metastatic BTC, were treatment naïve and had plans to initiate GC chemotherapy. On Day 1, pts received Gem 1000mg/m2 and Cis 25mg/m2 with TE 250 mg orally three times daily (TID) for 7 days. Thereafter, pts received TE 500 mg TID continuously plus GC therapy on days 1 and 8 of each 21-day cycle. The study comprised of 2 stages: stage 1 would enroll 20 patients with a safety run-in cohort in the first 6 pts to monitor safety and tolerability of TE + GC treatment for 21 days. Stage 2 would enroll 33 patients if no significant/unresolved grade 3 or higher toxicities related to study drug occurred in stage 1. The primary endpoint was 6-month (mo) progression free survival (PFS) rate according to RECIST 1.1. If 60% of pts (≥34) in the safety population were alive and progression free at 6-mos, the study was considered successful. Secondary endpoints included overall response rate (ORR) and disease control rate (DCR). Restaging occurred every 9 weeks using RECIST 1.1 and toxicities were graded using CTCAE v 5.0. Results: Between 2019 and 2021, fifty-three pts were enrolled across 12 study sites and comprised the safety population. The majority of pts were female (62.3%) and median age was 66 yrs (range 33 to 79). Baseline mean plasma 5-HIAA was 11.1 µg/L (ULN defined as &gt;10.8 µg/L). Thirty-one pts (58.5%) had plasma 5-HIAA levels ≤ULN and 22/53 (41.5%) had 5-HIAA levels &gt;ULN. Majority of pts had metastatic BTC (85%) and liver was the most common primary tumor site (66%). The 6-month PFS rate was 22.6% (12/53). Based on blinded independent central review, the ORR was 13.2% and DCR was 62.3%. Mean reduction in plasma 5-HIAA at 6 mos was -1.735 µg/L (SD 8.69) in 24 patients with available data. There was no difference in 6-mo PFS rate based on pts baseline 5-HIAA status; 58% (14/24) pts had ≥30% decrease from baseline in 5-HIAA, however there was no correlation with 6-month PFS. The most common TE related TEAEs were constipation (43.4%), nausea (28.3%) and fatigue (28.3%). Conclusions: The study did not achieve its primary endpoint of 60% of patients on TE plus GC chemotherapy being alive and progression free at 6 months. TE did reduce 5-HIAA levels in a subset of pts; however, this did not correlate to improved clinical outcomes. No significant safety issues noted with TE in combination with GC chemotherapy. Clinical trial information: NCT03790111 .

The interim analysis of a single-arm, open-label, phase II study investigating ALLEN regimen (durvalumab plus albumin paclitaxel and lenvatinib) in patients with unresectable biliary tract cancers (BTCs).

504 Background: BTCs are a heterogeneous group of malignancies with a poor prognosis. Despite the improved outcome achieved by the addition of the anti-PD-L1 antibody durvalumab to standard chemotherapy, the benefits were modest and cannot satisfy the clinical demands adequately. This study aimed to evaluate the efficacy and safety of the combination therapy of Albumin paclitaxel, Durvalumab and Lenvatinib (ALLEN regimen) in unresectable BTCs. Methods: This single-arm, single-center, open-label, phase I/Ⅱ study enrolled patients with locally advanced or metastatic BTCs. Eligible patients with ECOG score 0-2 were treated with ALLEN regimen. Durvalumab (1000mg IV, q3w) in combination with albumin paclitaxel (180-220 mg/m2 IV q3w) and lenvatinib (8mg PO QD) were given regularly until disease progression. The primary endpoint was objective response rate (ORR) evaluated by investigators according to RECIST 1.1. The secondary endpoints were disease control rate (DCR), progression-free survival (PFS) and treatment-related adverse events (TRAEs). Results: From September 2021 to September 2023, fourteen patients were enrolled including three patients who were failed to prior anti-PD-1 antibody treatment. The median follow-up was 6.8 months (95% CI 1.9, 10.9). The median age of the patients was 59.0 years, and male patients accounted for 35.7%. The ORR and DCR were 35.7% and 100%, respectively. The median PFS was 7.3 months (95% CI 4.9, 8.2). TRAEs of any grade occurred in 13 (92.9%) patients without grade 3 or higher. The most common TRAEs were alopecia (13/14, 92.9%), peripheral sensory neuropathy (10/14, 71.4%), decreased appetite and nausea (9/14, 64.3%), hypertension (6/14, 42.9%), rash (5/14, 35.7%), diarrhoea (4/14, 28.6%), and asthenia (4/14, 28.6%). Conclusions: The ALLEN regimen demonstrated encouraging anti-tumor activity with a tolerable safety profile in unresectable BTCs. The preliminary results were promising, which deserved further investigation in a larger population. Clinical trial information: NCT05327582 .

Galectin-9 as a regulator of immune interactions in the tumor microenvironment and novel therapeutic target in biliary tract cancer.

555 Background: While results of the TOPAZ-1 trial led to inclusion of anti-PD-1 therapy with standard of care gemcitabine/cisplatin chemotherapy for patients with unresectable biliary tract cancer (BTC), the improvement in overall survival is modest: 12.8 vs 11.5 mos. Identification of novel immunotherapeutic strategies remains a high priority. We discovered Galectin-9 (Gal-9), a carbohydrate-binding protein, is expressed in BTC; it has various immunosuppressive effects, including induction of apoptosis in T cells upon binding to its receptor Tim-3. Defining the role of Gal-9 in the BTC microenvironment will inform how to leverage it as a novel therapeutic target. Methods: Tissue microarrays (TMAs) were constructed from tumors of 66 patients who underwent curative-intent resection of BTC from 2000- 2015 at our institution. These TMAs underwent immunohistochemical staining for CD4, CD8, Gal-9 &amp; Tim-3; the percentage of cells staining positive for each marker was quantified. For each marker, martingale residual plots and bias-adjusted log rank tests were used to identify a cut-off value of “low” versus “high” expression where survival difference was maximal. For in vivo mouse experiments, the syngeneic BTC cell line URCCA4.3 was injected subcutaneously into the flank of C57BL/6 mice, followed by 3 weeks of treatment with anti-Galectin-9 or anti-Tim-3 antibody alone or in combination with anti-PD-1 antibody. Tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry. Results: Median overall survival (mOS) was significantly improved in patients with high Gal-9 expression in their tumors, compared to those with low (32.5 mos vs 17.6 mos, p=0.018). However, when patients with high Gal-9 expression were further stratified according to Tim-3, patients with both high Gal-9 &amp; high Tim-3 expression had significantly worse mOS than those with low Tim-3 (22.7 mos vs 113.9 mos, p=0.031), implying that interaction between Gal-9 and Tim-3 wields significant impact on TIL function. There was no difference in OS based on Tim-3 expression alone. When mice bearing BTC tumors were treated with Gal-9 or Tim-3 antibody monotherapy, there was no significant change in tumor growth versus control, but when either was used in combination with PD-1 inhibition, there was a significant reduction in tumor burden at study endpoint. Mice treated with either dual therapy had a significant decrease in CD4+ Treg and increase in CD4+ effector memory TIL populations compared to monotherapy (p&lt;0.05). Conclusions: This study provides unique insight into the role for targeting the Gal-9/Tim-3 pathway in BTC. Our clinical data highlights that co-expression of these markers in BTC tumors is associated with significantly worse OS. Our in vivo pre-clinical studies demonstrate that blockade of either Gal-9 or Tim-3 synergizes with PD-1 targeted antibodies for superior anti-tumor efficacy.

Epidemiology, treatment patterns, and humanistic and economic burden of biliary tract carcinoma: A systematic and targeted literature review.

443 Background: Patients with biliary tract cancers (BTC) are typically diagnosed at late stage, with limited treatment options. As such, BTC is associated with poor prognosis, high economic burden and reduced health-related quality of life (HRQoL). As the treatment paradigm is evolving, with multiple immunotherapies showing promise, this study aimed to assess the current disease and treatment landscape. Methods: Systematic literature reviews (Embase, MEDLINE, Cochrane, NHS-EED; database inception to Feb 10, 2023) were conducted for HRQoL and economic burden. Targeted literature reviews (Embase, MEDLINE) were conducted for epidemiology (Jan 01 2017–Feb 06 2023) and treatment guidelines/patterns (Jan 01 2012–Feb 06 2023). Conference abstracts were also searched (2019–2022). Eligibility criteria included global studies (English language) in adults with metastatic and/or unresectable BTC. Results: Overall, 264 studies were included (epidemiology=170, treatment guidelines=14, treatment patterns=50, HRQoL=12, economic burden=18). In the US, Europe and Asia, age-standardized incidence rates were 5.04, 8.39–8.78 and 9.1–10.1 (per 100,000 person-years) and prevalence rates were 0.01%, 0.02–0.34% and 0.02–2.61%, respectively. Treatment pattern studies were mainly from Asia, Europe (n=19 each) and North America (n=10). Gemcitabine [gem]-based chemotherapy was most common in 1L BTC (24–100%) and fluorouracil-based regimens were common in 2L+ BTC (12.3–74.3%). Median overall survival (mOS) for gem-based and fluorouracil-based 1L regimens were 7.7–14.8 months and 7–16.7 months, respectively. Disease progression/toxicity frequently led to treatment discontinuation/dose modifications. In the US, use of non-guideline-based regimens increased by line of therapy (LOT). Among the clinical studies (n=5) reporting HRQoL in 1L, n=4 assessed gem-based combinations. BTC impaired HRQoL domains for anxiety, tiredness (EORTC QLQ-BIL21), work productivity, activity impairment (WPAI scale) and depression (PHQ-9). BTC was associated with substantial economic burden. Mean total all-cause healthcare costs per patient per month (PPPM) increased by LOT (US; 1L: $19,589–25,517, 2L: $22,617–29,721, 3L: $23,256–33,534). US healthcare resource utilization in 1L was driven by outpatient visits (98%), emergency department visits (33–80%) and hospitalization (70–80%). Mean hospital stay ranged from 0.6–7 days PPPM. Conclusions: Epidemiology data varied between Western and Asian populations, but gem-based chemotherapy was identified as the standard of care across regions. There is high unmet need in advanced BTC, as existing options are characterized by poor survival outcomes and considerable economic burden. These findings indicate a need for novel approaches for the management of BTC.

ZSAB-TOP: A phase 2 trial of tislelizumab (TIS) and ociperlimab (OCI) combined with gemcitabine and cisplatin (GemCis) as the first-line treatment for advanced biliary tract cancer (BTC).

475 Background: GemCis has long been the standard-of-care for advanced BTC, however the prognosis remains poor. Combinations with immunotherapy and GemCis are being explored in BTC. This study aimed to evaluate the efficacy and safety of TIS (an anti-PD-1 antibody) and OCI (a TIGIT inhibitor) combined with GemCis as the first-line treatment for advanced BTC. Herein, the primary analysis results of this study were reported. Methods: In this open-label, single-arm, multicenter phase 2 study, systematic treatment-naïve pts with unresectable advanced BTC received TIS (200 mg, day1, Q3W), OCI (900 mg, day1, Q3W), and GemCis (Gem 1000 mg/m2 and Cis 25 mg/m2 on days 1 and 8 Q3W, up to 8 cycles). The primary endpoint was investigator-assessed objective response rate (ORR) per RECIST v1.1. Secondary endpoints included disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety. A binomial exact test with a one-sided α of 0.05 was performed in the analysis of the primary endpoint to test the historical ORR of 25% with GemCis. If p≤0.05, the statistical superiority of the study treatment would be claimed. Results: A total of 45 pts were enrolled, with 75.6% having intrahepatic cholangiocarcinoma and 60.0% metastatic disease. As of 24 Aug 2023 (median follow-up, 8.0 months), 24.4% (11/45) pts remained on study treatment. Among the 41 pts in efficacy analysis set, confirmed ORR (cORR) was 48.8% (20/41, 95% CI, 32.9-64.9, p=0.0009), with 1 complete response. The statistical superiority was achieved. The subgroups of TIGIT+ pts tended to have numerically higher cORR (Table). Median PFS was 7.7 months, with 6-month PFS rate of 67.6%. Median OS was not reached, and 6-month OS rate was 86.2%. Grade ≥3 treatment-related adverse events rate was 60% (27/45). Immune-mediated adverse events rate was 37.8% (17/45), which were mostly grade 1 and 2. Conclusions: The combination of TIS and OCI plus GemCis showed promising anti-tumor activity with manageable safety as the first-line treatment for advanced BTC. Clinical trial information: NCT05023109 . [Table: see text]

PD-L1 as a predictor of chemo-immunotherapy response in biliary tract cancers: A systematic review and meta-analysis.

541 Background: Advanced biliary tract cancers (BTCs) are rare and aggressive malignancies with limited treatment options. Recently, immune checkpoint inhibitors in combination with chemotherapy (ICI-C) gained approval as first-line therapy for unresectable or metastatic BTCs. Two large phase III clinical trials of ICI-C in BTCs did not show a significant correlation between PD-L1 expression and therapeutic response. However, in a phase II study of single-agent nivolumab, there was an association. In light of these conflicting findings, we conducted a comprehensive systematic review and meta-analysis of clinical trials investigating ICI-C in BTCs to assess whether PD-L1 expression could predict treatment response. Methods: We searched PubMed, Web of Science, EMBASE, and Cochrane databases to identify relevant studies. Patient characteristics, method of PD-L1 assessment, and measures of treatment response including hazard ratio (HR), objective response rate (ORR), progression-free-survival (PFS), and overall survival (OS) were extracted. Pooled ORR and HR were calculated using random effect model and assessed for study heterogeneity. Results: Among the 4,882 studies screened, seven clinical trials evaluating the efficacy of ICI-C in BTCs were identified. Of these trials, two randomized phase III trials report HR between PD-L1 positive and negative patients, while five phase II clinical trials reported ORR based on PD-L1 expression. Out of the 1,069 patients included in these trials, 954 underwent assessment for PD-L1 expression. 66.4% (n=634) exhibited PD-L1 expression level ≥ 1% as determined by either tumor proportion score (TPS) or combined positive score (CPS), while 33.5% (n=320) were classified as PD-L1 negative. Notably, 115 patients were not tested for PD-L1 expression, a variety of PD-L1 assays were used across the studies, and only some studies reported multiple PD-L1 cutoffs. Pooled analysis of two-phase III trials demonstrated that PD-L1 expression ≥ 1% was associated with improved OS (pooled HR 0.83, 95% CI 0.72-0.95) compared to PD-L1 &lt; 1% (pooled HR 0.85, 95% CI 0.67-1.07). Additionally, pooled ORR from five phase II studies showed a trend towards an improved response in patients with PD-L1 expression ≥ 1% (pooled ORR 64%, 95% CI 52-74%) compared to PD-L1 &lt;1% (pooled ORR 46%, 95% CI 31-62%) with a subgroup difference p-value of 0.08. Conclusions: This meta-analysis suggests that BTCs patients with PD-L1 expression ≥ 1% may exhibit a more favorable response to chemo-immunotherapy, and that a majority of BTCs have this level of expression. These findings support further investigation of the use of PD-L1 as a biomarker, and in particular investigation of different PD-L1 levels, which may inform treatment for patients with relative contraindications to immunotherapy use.

A phase II study to evaluate the safety and efficacy of anlotinib combined with toripalimab for advanced biliary tract cancer.

To assess the safety and efficacy of anlotinib (a multi-targeted tyrosine kinase inhibitor) combined with toripalimab (a PD-1 monoclonal antibody) in the treatment of unresectable biliary tract cancer (BTC). In this prospective, single-arm, single-centre exploratory clinical study, patients with locally progressed or metastatic BTC were included. Patients were treated with anlotinib (12 mg, PO, QD, for 2 weeks and then stopped for a week, 21 days for a cycle) and toripalimab (240 mg, IV, Q3W). The primary endpoint of the study was the objective response rate (ORR), as defined in RECIST version 1.1 criteria. In this study, 15 BTC patients who met the criteria were enrolled. The ORR was 26.7%, the median progression-free survival (mPFS) was 8.6 months (95% CI: 2.1-15.2), the median overall survival (mOS) was 14.53 months (95% CI: 0.8-28.2) and the disease control rate (DCR) was 87.6%. A patient with hilar cholangiocarcinoma was successfully converted after three cycles of treatment and underwent surgical resection. Furthermore, patient gene sequencing revealed that STK11 was mutated more frequently in patients with poor outcomes. In addition, patients with a CD8/Foxp3 ratio > 3 had a longer survival than those with a CD8/Foxp3 ratio ≤ 3 (P = 0.0397). In patients with advanced BTC, the combination of anlotinib and toripalimab demonstrated remarkable anti-tumor potential, with increased objective response rates (ORR), longer overall survival (OS) and progression-free survival (PFS). Moreover, STK11 and CD8/Foxp3 may be as biomarkers that can predict theeffectiveness of targeted therapy in combination with immunotherapy.

New Era of Immune-Based Therapy in Intrahepatic Cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (CC) accounts for approximately 20% of all biliary tract cancer (BTC) cases and 10-15% of all primary liver cancer cases. Many patients are diagnosed with unresectable BTC, and, even among patients with resectable BTC, the 5-year survival rate is approximately 20%. The BTC incidence rate is high in Southeast and East Asia and has increased worldwide in recent years. Since 2010, cytotoxic chemotherapy, particularly combination gemcitabine + cisplatin (ABC-02 trial), has been the first-line therapy for patients with BTC. In 2022, a multicenter, double-blind, randomized phase 3 trial (TOPAZ-1 trial) examined the addition of programmed death-ligand 1 immunotherapy (durvalumab) to combination gemcitabine + cisplatin for BTC treatment, resulting in significantly improved survival without notable additional toxicity. As a result of this trial, this three-drug combination has become the new standard first-line therapy, leading to notable advances in BTC management for the first time since 2010. The molecular profiling of BTC has continued to drive the development of new targeted therapies for use when first-line therapies fail. Typically, second-line therapy decisions are based on identified genomic alterations in tumor tissue. Mutations in fibroblast growth factor receptor 1/2/3, isocitrate dehydrogenase 1/2, and neurotrophic tyrosine receptor kinase A/B/C are relatively frequent in intrahepatic CC, and precision medicines are available that can target associated pathways. In this review, we suggest strategies for systemic pharmacotherapy with a focus on intrahepatic CC, in addition to presenting the results and safety outcomes of clinical trials evaluating immune checkpoint inhibitor therapies in BTC.

Phase II study of fruquintinib as second or further-line therapy for patients with advanced biliary tract cancer.

e16161 Background: Biliary tract cancer (BTC) is a rare but aggressive disease, and most patients present with unresectable or metastatic disease. Gemcitabine combined with cisplatin (GP) has been established as the standard first-line treatment in patients with unresectable BTC. Nevertheless, no standard second or further-line treatment regimen has been approved in this disease. Fruquintinib is an oral multi-kinase inhibitor targeting vascular endothelial growth factor receptor 1 (VEGFR1), VEGFR2 and VEGFR3. In this single arm phase II study, we explored the efficacy and safety of fruquintinib as a novel second or further-line therapy in advanced or metastatic BTC. Methods: BTC patients with ECOG PS 0-1 and adequate liver, kidney and bone marrow function were given fruquintinib (5 mg, PO, D1-21, Q4W) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. The exploratory endpoint was the correlation of clinical outcomes with biomarkers. Results: 20 patients were enrolled in the study. 9(45.0%) were men, and the median age was 57.5(36-78) years. 18 patients were diagnosed with ICC, 1 with ECC, and 1 with GBC. 6 (30%) patients were refractory to second-line treatment, and 5 (25%) patients were refractory to third-line treatment. 18 patients were assessable for response. The median PFS was 4.6 months (95%CI: 2.1-7.1 months). ORR was 5.6%, and DCR was 66.7%. The incidence of treatment-related grade 1-2 adverse events (TRAEs) was 83.3%, and the most common grade 1-2 AEs were hand-foot syndrome (66.6%), fatigue (61.1%), stomatitis (44.4%), and hypertension (38.9%). Conclusions: Fruquintinib showed promising efficacy and acceptable toxicity as second or further-line therapy in advanced or metastatic BTC. Clinical trial information: NCT04156958 .

Results from the pivotal phase (Ph) 2b HERIZON-BTC-01 study: Zanidatamab in previously-treated HER2-amplified biliary tract cancer (BTC).

4008 Background: For patients (pts) with locally advanced/metastatic BTC who progress after first-line treatment (tx), standard tx offers limited clinical benefit with modest improvement in survival. HER2-targeted therapies have improved survival in breast and gastric cancer, but there is no approved HER2-targeted therapy for BTC. Zanidatamab (zani), a HER2-targeted bispecific antibody, has shown durable responses in a subset of pts with BTC in a Ph 1 trial. Methods: HERIZON-BTC-01, an open-label, global Ph 2b study (NCT04466891), evaluated zani (20 mg/kg IV every 2 wks) in pts with HER2-amplified, locally advanced unresectable or metastatic BTC (gallbladder cancer [GBC], intra-/extra-hepatic cholangiocarcinoma [ICC/ECC]) who had received prior gemcitabine-containing therapy; pts with prior HER2-targeted therapies were excluded. Pt cohort assignment was based on tumor immunohistochemistry (IHC) status: Cohort 1 for IHC 2+/3+ (HER2 positive), or Cohort 2 for IHC 0/1+. Tumors were assessed every 8 wks per RECIST 1.1. The primary endpoint was confirmed objective response rate (cORR) by independent central review (ICR) in Cohort 1. Secondary endpoints included other efficacy and safety outcomes. Results: Enrollment is complete with 87 pts (Cohort 1, n=80; Cohort 2, n=7) treated. Median age was 64 yrs (range, 32-79); 54% were female; 66% were Asian; 52% had GBC, 30% ICC, and 18% ECC. Pts had a median of 1 line (range, 1-7) of prior therapy in the locally advanced/metastatic setting. In Cohort 1, cORR was 41% with median duration of response (DOR) of 12.9 months (m; 95% CI: 5.95, not estimable); median study follow-up time was 12.4 m. Among the 33 responders at the data cut (10OCT2022), 49% had ongoing responses and 82% had a DOR of ≥16 wks. Median time to first response was 1.8 m (range, 1.6-5.5). Progression-free survival and overall survival are being evaluated. No responses were observed in Cohort 2. In both cohorts (N=87), tx-related adverse events (TRAEs) occurred in 72% of pts; TRAEs in ≥10% of pts were diarrhea (37%) and infusion-related reaction (33%). Gr 3 TRAEs occurred in 18% of pts, with diarrhea (4.6%) and ejection fraction (EF) decreased (3.4%) in &gt;3% of pts. Two pts (2.3%) discontinued zani due to an AE (EF decreased and non-infectious pneumonitis). Seven pts had serious TRAEs; no AE preferred term occurred in &gt;1 pt. No zani-related Gr 4 AEs or deaths were reported. Conclusions: Results of the pivotal HERIZON-BTC-01 study indicate that the HER2 bispecific antibody zani demonstrates rapid, durable responses with a manageable safety profile in pts with tx-refractory HER2-positive BTC. Given these data, zani continues to be developed as a tx option in HER2-positive BTC. Clinical trial information: NCT04466891 . [Table: see text]

Randomized phase 2 study of maintenance olaparib vs olaparib plus durvalumab for DNA damage repair (DDR) gene mutated unresectable or metastatic biliary tract cancer (BTC) with durable response to first-line platinum-based chemotherapy: OPTIMUM trial.

TPS4180 Background: BTC is rare and aggressive disease with heterogeneous genetic profiles. Gemcitabine plus cisplatin (GemCis) with or without durvalumab is the standard first-line therapy but further improvement in survival outcomes is needed. In a prior study (Chae HJ et al, Eur J Cancer 2019), germline or somatic mutations in DDR genes including BRCA are detected more than half of BTC patients and associated with better survival outcomes with platinum-based chemotherapy. As the potential efficacy of Olaparib in DDR-mutated cancers and synergism between PARP inhibitors and immune checkpoint inhibitors, we designed randomized phase 2 trial investigating the efficacy and safety of olaparib monotherapy vs olaparib plus durvalumab in BTC patients as maintenance therapy for BTC patients who showed durable response to first-line platinum-based chemotherapy. Methods: This is a randomized, open-label phase 2 study conducted in a single center (Asan Medical Center, Seoul, Korea). Key eligibility criteria include histologically documented locally advanced unresectable or metastatic BTC, no progression at least 16 weeks with first-line platinum-based chemotherapy, DDR mutations on targeted sequencing of tumor tissues and ctDNA, ECOG performance status 0–1, and adequate organ function. Eligible patients will be randomized 1:1 into olaparib monotherapy arm (300 mg twice daily, every 4 weeks) or olaparib plus durvalumab (1,500 mg intravenous, every 4 weeks) arm. Study treatment is continued until disease progression, unacceptable toxicity, withdrawal of consent, or death. Response evaluation is performed every 8 weeks (fixed). Stratification factors are tumor location (intrahepatic vs extrahepatic/gallbladder) and best response to platinum-based chemotherapy (CR/PR vs SD). The six-month progression-free survival rates are the primary endpoint and overall survival, progression-free survival, response rates, and safety profiles are secondary endpoints. A total of 62 patients (31 for each arm) are planned, and 23 (37%) patients (ATM [n=6], BRCA2 [n=7], CHEK2 [n=2], BRCA1 [n=1], RAD51C [n=1], and PBRM1 [n=1]) are enrolled as of Jan 2023. Clinical trial information: NCT05222971 .

A phase II study of tremelimumab, durvalumab, and bevacizumab in advanced biliary tract cancers.

e16110 Background: Biliary tract cancers (BTC) have a dismal prognosis. Recently, standard of care changed by adding durvalumab (D) to chemotherapy after the TOPAZ-1 study demonstrated an extended and durable survival benefit (median OS: 12.8 vs 11.5 months; 24-month OS rate: 23.6% vs 11.5%). Extrapolating from IMbrave150 and HIMALAYA trials in liver cancer, we combined an anti-VEGF monoclonal antibody with the STRIDE regimen (Single Tremelimumab Regular Interval Durvalumab) in advanced BTC. Methods: This is a phase II single center trial of unresectable or metastatic BTC with a safety run-in included (NCT03937830). In schedule A, the first 6 patients (pts) received single dose T 300mg with D 1,150mg flat dose + bevacizumab (B) 7.5mg/kg/dose every 21 days until disease progression or unacceptable toxicity. In schedule B, the next 8 pts did not start B until cycle 2 (C2); all other scheduling and dosing remained the same. Paired tumor tissue and blood were collected before and on treatment for correlative studies. Primary endpoint was 6-month PFS, and secondary endpoints were safety and feasibility, OS, and best ORR according to Response Evaluation Criteria (RECIST 1.1). Results: We enrolled 14 pts as of data cutoff (1/11/23) with 8 patients alive (median follow-up 4.3 mo, 0.7-17.7). Accrual is expected to be completed by June 2023 with 20 evaluable pts; interim analysis presented early due to vital unexpected results with different dosing schedules. Updated data will be presented at ASCO along with 6-month PFS and correlative studies. We treated 6 pts with schedule A and observed ORR 17% (PR x 1, SD x 4, PD x1), mPFS 8.5 mo (96% CI: 1.8 - NE), and mOS not reached (range: 3.0 - 17.7 mo). 50% of pts experienced G3 or G4 immune-related adverse events (irAE), including overlapping myositis-myocarditis-myasthenia gravis syndrome, thyroiditis, colitis, and hepatitis; these pts received systemic steroids and were taken off treatment. irAE occurred early after initiation of treatment with most presenting within 40 days. Based on the high rate of severe irAE, we changed to schedule B and treated 8 pts. We observed ORR 0% (SD x 1, PD x 5, unevaluable x 2), mPFS 2.6 mo (96% CI: 0.9 - 3.9), and mOS 4.7 mo (95% CI: 0.9 - 4.7). There were no G3 or G4 irAE; there was 1 death from tumor-related bleed that occurred prior to restaging in C2 and may have been worsened by bevacizumab. Clinical response appears to diminish with treatment schedule change, albeit small numbers limit interpretation (Cochran-Armitage trend test, p = 0.0671). Conclusions: The combination of anti-VEGF with anti-PDL1 and anti-CTLA4 appears to induce a strong immune response in advanced BTC with more severe and earlier irAE. In contrast, historical data showed limited benefit with D+T alone in BTC. We observed that modifying dosing schedule may impact outcomes by reducing efficacy when the three drugs are not given together. Clinical trial information: NCT03937830 .

CO117 Real-World Treatment Patterns and Outcomes in Unresectable Advanced and Metastatic Biliary Tract Cancers (BTC): A Literature Review

BTC are rare, aggressive malignancies typically diagnosed when disease is metastatic or unresectable, precluding curative treatment. This literature review aimed to identify treatment guidelines and real-world treatment patterns and outcomes for unresectable advanced and metastatic BTC.

Efficacy and safety of PD‑1 inhibitor plus antiangiogenic treatment in patients with unresectable biliary tract cancer: A multicenter retrospective study.

Immunotherapy and antiangiogenic therapy have shown promising clinical activity in patients with advanced biliary tract cancer (BTC) in clinical trials. As the combination of these two treatments for BTC is not well studied in the real world, the present study retrospectively analyzed the clinical outcomes of patients with unresectable BTC who received immunotherapy-antiangiogenesis combination therapy in a real-world setting. A three-center, retrospective study was performed on patients with unresectable BTC who received a combination of programmed death 1 inhibitor and antiangiogenic agent between March 26, 2019 and November 1, 2021 in China. In total, 68 patients were enrolled in the cohort. The objective response rate and disease control rate were 13.2 and 75.0%, respectively. The median time to progression, progression-free survival and overall survival were 8.2, 5.5 and 10.7 months, respectively. Adverse events of all grades occurred in 58 patients (85.3%). In conclusion, the present study demonstrated that immunotherapy-antiangiogenesis combination therapy may be considered a therapeutic option for patients with unresectable BTC. Further prospective investigations are needed.