Dataset Information

IMbrave 151: a randomized phase II trial of atezolizumab combined with bevacizumab and chemotherapy in patients with advanced biliary tract cancer.

ABSTRACT:

Background

Biliary tract cancers (BTCs) are heterogenous, highly aggressive tumors that harbor a dismal prognosis for which more effective treatments are needed. The role of cancer immunotherapy in BTC remains to be characterized. The tumor microenvironment (TME) of BTC is highly immunosuppressed and combination treatments are needed to promote effective anticancer immunity. Vascular endothelial growth factor (VEGF) drives immunosuppression in the TME by disrupting antigen presentation, limiting T-cell infiltration, or potentiating immune-suppressive cells. Many VEGF-regulated mechanisms are thought to be relevant to repressed antitumor immunity in BTC, making dual targeting of VEGF and programmed cell death protein 1 (PD-1)/PD-L1 pathways a rational approach. Gemcitabine and Cisplatin (Gem/Cis) can also modulate anticancer immunity through overlapping and complementary mechanisms to those regulated by VEGF. Anti-PD-L1/VEGF inhibition, coupled with chemotherapy, may potentiate antitumor immunity leading to enhanced clinical benefit.

Methods

IMbrave 151 is a randomized, double-blind, placebo-controlled, multicenter, international phase II study to evaluate atezolizumab (a PD-L1 inhibitor) in combination with chemotherapy (gemcitabine and cisplatin) and bevacizumab (an anti-VEGF monoclonal antibody) as a first-line treatment for advanced BTC. Approximately 150 patients with previously untreated, advanced BTC will be randomized to either Arm A (atezolizumab + bevacizumab + Gem/Cis) or Arm B (atezolizumab + placebo + Gem/Cis). Randomization is stratified by the presence of metastatic disease, primary tumor location, and geographic region. The primary efficacy endpoint is investigator-assessed progression-free survival (PFS) per RECIST 1.1. Secondary endpoints include objective response rate (ORR), duration of response (DoR), disease control rate (DCR), overall survival (OS), and safety and patient reported outcomes (PROs). Tissue, blood, and stool samples will be collected at baseline and on-treatment in order to perform correlative biomarker analyses.

Discussion

IMbrave 151 represents the first randomized study to evaluate combined PD-L1/VEGF blockade on a chemotherapy backbone in BTC.

Trial registration

NCT identifier: NCT04677504; EUDRACT number: 2020-003759-14.

SUBMITTER: Hack SP

PROVIDER: S-EPMC8326820 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Project description:ObjectiveThe treatment of biliary tract (BTC) cancer remains relatively limited, especially in the setting of advanced BTC. Immune checkpoint inhibitors (ICIs) have shown some effects in a variety of solid tumors, but their efficacy and safety in patients with advanced BTC are still elusive, which require in-depth analysis.MethodsThe clinical information of 129 patients diagnosed with advanced BTC between 2018 and 2021 were retrospectively reviewed. All patients were treated with chemotherapy, while a portion of them (64 patients) were treated with ICIs, the other 64 patients were not. Therefore, we divided the patients into two groups, SC (standard chemotherapy) and CI (chemotherapy in combined with immunotherapy), then we analyzed the benefit of adding ICIs according to efficacy, adverse events, progression-free survival (PFS), progressive disease (PD), and the influence of various factors and effectiveness.ResultsThe mean PFS was 9.67 months for CI group and 6.83 months for SC group. The PFS was prolonged by 2.84 months with ICI addition, and the difference was statistically significant (t = 3.114, 95% CI: 1.06-4.74, p < 0.001). The objective response rate (ORR) was 32.81% (21/64) for the CI group versus 10.77% (7/65) for the SC group, and the disease control rate (DCR) was 79.69% (51/64) versus 67.69% (44/65), respectively. Regression analysis showed that factors such as changes in CA19-9, the level of PD-L1 expression, tobacco and alcohol, and the neutrophil-lymphocyte (NLR) ratio all influenced PFS (p < 0.05 for all these factors). For the treatment-related adverse events (TRAEs), the highest grade 3-4 adverse effects were thrombocytopenia in 7.75% (10/129) and neutropenia in 3.1% (4/129), immune-related adverse events (irAEs) occurred in 32.8% (21/64), and all were grade 1-2.ConclusionsOur results showed that ICIs combined with chemotherapy exhibited good antitumor activity with acceptable safety and could be recommended as first-line treatment for patients with advanced BTC.