Cell-Free Tumor DNA Dominant Clone Allele Frequency Is Associated With Poor Outcomes in Advanced Biliary Cancers Treated With Platinum-Based Chemotherapy

A drug safety evaluation of pemigatinib for advanced cholangiocarcinoma

INTRODUCTION

Pemigatinib is a selective small-molecule inhibitor of the fibroblast growth factor receptor (FGFR) 1-3. FGFR is associated with increased cell division, proliferation, and survival. Inhibition of this receptor is an effective treatment against tumors driven by activated fusions in FGFR2.

AREAS COVERED

The drug was first evaluated in patients with advanced solid tumors and demonstrated a manageable safety profile, with the most common adverse events being oscillations in blood phosphate levels, fatigue, gastrointestinal symptoms, and skin and ocular toxicities. Pemigatinib was further evaluated in a phase II cohort study of patients with previously treated locally advanced or metastatic cholangiocarcinoma harboring FGFR2 genomic alterations. After a median follow-up of 17.8 months, the objective response rate in patients with tumors harboring FGFR2 fusions or rearrangements was 35.5% (95% CI, 26.5-45.4). Based on these results, the FDA granted accelerated approval on 17 April 2020, to pemigatinib, for the treatment of adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with an FGFR2 fusion or another rearrangement. Articles selected for this review were based on reported studies indexed in PubMed (2010-2023).

EXPERT OPINION

Future perspectives in the treatment of FGFR2 fused cholangiocarcinoma include the evaluation of pemigatinib in previously untreated patients and possible active combinations or sequencing strategies with other drugs.

Moving beyond single-agent checkpoint inhibition in biliary tract cancers: what is the next frontier?

Background: Immunotherapy has been shown to improve outcomes for patients with cancer. Biliary tract cancers are a group of lethal diseases, and immunotherapy is an exciting new strategy to treat patients in advanced stages. Role of immunotherapy in biliary cancers: Durvalumab, an anti-PD-L1 antibody, is a new immunotherapy option for patients with advanced biliary cancers. In a randomized phase III trial, the combination of durvalumab and chemotherapy improved disease outcomes, including overall survival, in patients with advanced biliary cancers regardless of PD-L1 expression. Future perspective: Promising new combinations with new and potent antibodies or antiangiogenics are under development. Combinations with new immunotherapy agents targeting CTLA-4 or OX40 can enhance T-cell activation and improve outcomes compared with single anti-PD-1/PD-L1 agents. Furthermore, ctDNA is being used as an alternative to tissue genomic analysis and can be used to identify actionable targets. In this review, we will discuss the most important studies involving immunotherapy in biliary cancers as well as future perspectives in the field.

State of the Art: ctDNA in Upper Gastrointestinal Malignancies

Circulating tumor DNA (ctDNA) has emerged as a promising non-invasive source to characterize genetic alterations related to the tumor. Upper gastrointestinal cancers, including gastroesophageal adenocarcinoma (GEC), biliary tract cancer (BTC) and pancreatic ductal adenocarcinoma (PADC) are poor prognostic malignancies, usually diagnosed at advanced stages when no longer amenable to surgical resection and show a poor prognosis even for resected patients. In this sense, ctDNA has emerged as a promising non-invasive tool with different applications, from early diagnosis to molecular characterization and follow-up of tumor genomic evolution. In this manuscript, novel advances in the field of ctDNA analysis in upper gastrointestinal tumors are presented and discussed. Overall, ctDNA analyses can help in early diagnosis, outperforming current diagnostic approaches. Detection of ctDNA prior to surgery or active treatment is also a prognostic marker that associates with worse survival, while ctDNA detection after surgery is indicative of minimal residual disease, anticipating in some cases the imaging-based detection of progression. In the advanced setting, ctDNA analyses characterize the genetic landscape of the tumor and identify patients for targeted-therapy approaches, and studies show variable concordance levels with tissue-based genetic testing. In this line, several studies also show that ctDNA serves to follow responses to active therapy, especially in targeted approaches, where it can detect multiple resistance mechanisms. Unfortunately, current studies are still limited and observational. Future prospective multi-center and interventional studies, carefully designed to assess the value of ctDNA to help clinical decision-making, will shed light on the real applicability of ctDNA in upper gastrointestinal tumor management. This manuscript presents a review of the evidence available in this field up to date.

Optimizing Circulating Tumour DNA Use in the Perioperative Setting for Intrahepatic Cholangiocarcinoma: Diagnosis, Screening, Minimal Residual Disease Detection and Treatment Response Monitoring

In this review, we present the current evidence and future perspectives on the use of circulating tumour DNA (ctDNA) in the diagnosis, management and understanding the prognosis of patients with intrahepatic cholangiocarcinoma (iCCA) undergoing surgery. Liquid biopsies or ctDNA maybe utilized to: (1) determine the molecular profile of the tumour and therefore guide the selection of molecular targeted therapy in the neoadjuvant setting, (2) form a surveillance tool for the detection of minimal residual disease or cancer recurrence after surgery, and (3) diagnose and screen for early iCCA detection in high-risk populations. The potential for ctDNA can be tumour-informed or -uninformed depending on the goals of its use. Future studies will require ctDNA extraction technique validations, with standardizations of both the platforms and the timing of ctDNA collections.

Novel precision therapies for cholangiocarcinoma: an overview of clinical trials

INTRODUCTION

The treatment landscape of biliary cancers is rapidly changing. Inhibitors against the actionable targets FGFR and IDH1 are now being included in the treatment guidelines of multiple countries for patients with advanced cholangiocarcinoma. However, there remains an unmet need in identifying the mechanisms of resistance and treatment strategies involving possible tumor sequencing.

AREAS COVERED

In this review article, we address clinical trials evaluating FGFR, IDH, BRAF and HER2 inhibitors in advanced cholangiocarcinoma. We also review the mechanisms of resistance described thus far and approaches to overcome them. Articles selected for this review were based on reported studies indexed in PubMed (2010-2022).

EXPERT OPINION

Precision medicine in biliary cancers has already been incorporated into the treatment landscape of the disease in many countries. Fusions of FGFR2 and mutations in IDH1 are the first drivers with targetable treatments approved in these cancers. HER2 and BRAF would be the next drivers with possible tumor-agnostic or cholangiocarcinoma-specific approvals. The advent of ctDNA could improve the accessibility of sequencing and recruitment in these clinical trials. However, limitations of detecting fusions should be considered and addressed in these platforms.

Combining of chemotherapy with targeted therapy for advanced biliary tract cancer: A systematic review and meta-analysis

BACKGROUND

Targeted therapy (TT) has resulted in controversial efficacy as first-line treatment for biliary tract cancer (BTC). More efficacy comparisons are required to clarify the overall effects of chemotherapy (CT) combined with TT and CT alone on advanced BTC.

AIM

To conduct a meta-analysis of the available evidence on the efficacy of CT combined with TT for advanced BTC.

METHODS

The PubMed, EMBASE, ClinicalTrials, Scopus and Cochrane Library databases were systematically searched for relevant studies published from inception to August 2022. Only randomized clinical trials (RCTs) including comparisons between the combination of gemcitabine-based CT with TT and CT alone as first-line treatment for advanced BTC were eligible (PROSPERO-CRD42022313001). The odds ratios (ORs) for the objective response rate (ORR) and hazard ratios (HRs) for both progression-free survival (PFS) and overall survival (OS) were calculated and analyzed. Subgroup analyses based on different targeted agents, CT regimens and tumor locations were prespecified.

RESULTS

Nine RCTs with a total of 1361 individuals were included and analyzed. The overall analysis showed a significant improvement in ORR in patients treated with CT + TT compared to those treated with CT alone (OR = 1.43, 95%CI: 1.11-1.86, P = 0.007) but no difference in PFS or OS. Similar trends were observed in the subgroup treated with agents targeting epidermal growth factor receptor (OR = 1.67, 95%CI: 1.17-2.37, P = 0.004) but not in the subgroups treated with agents targeting vascular endothelial growth factor receptor or mesenchymal-epithelial transition factor. Notably, patients who received a CT regimen of gemcitabine + oxaliplatin in the CT + TT arm had both a higher ORR (OR = 1.75, 95%CI: 1.20-2.56, P = 0.004) and longer PFS (HR = 0.83, 95%CI: 0.70-0.99, P = 0.03) than those in the CT-only arm. Moreover, patients with cholangiocarcinoma treated with CT + TT had significantly increased ORR and PFS (ORR, OR = 2.06, 95%CI: 1.27-3.35, PFS, HR = 0.79, 95%CI: 0.66-0.94).

CONCLUSION

CT + TT is a potential first-line treatment for advanced BTC that leads to improved tumor control and survival outcomes, and highlighting the importance of CT regimens and tumor types in the application of TT.

Circulating Tumor DNA Allele Fraction: A Candidate Biological Signal for Multicancer Early Detection Tests to Assess the Clinical Significance of Cancers

Current imaging-based cancer screening approaches provide useful but limited prognostic information. Complementary to existing screening tests, cell-free DNA-based multicancer early detection (MCED) tests account for cancer biology [manifested through circulating tumor allele fraction (cTAF)], which could inform prognosis and help assess the cancer's clinical significance. This review discusses the factors affecting circulating tumor DNA (ctDNA) levels and cTAF, and their correlation with the cancer's clinical significance. Furthermore, it discusses the influence of cTAF on MCED test performance, which could help inform prognosis. Clinically significant cancers show higher ctDNA levels quantified by cTAF than indolent phenotype cancers within each stage. This is because more frequent mitosis and cell death combined with increased trafficking of cell-free DNA into circulation leads to greater vascularization and depth of tumor invasion. cTAF has been correlated with biomarkers for cancer aggressiveness and overall survival; cancers with lower cTAF had better survival when compared with cancers as determined by the higher cTAF and Surveillance, Epidemiology, and End Results-based survival for that cancer type at each stage. MCED-detected cancers in case-control studies had comparable survival to Surveillance, Epidemiology, and End Results-based survival at each stage. Because many MCED tests use ctDNA as an analyte, cTAF could provide a common metric to compare performance. The prognostic value of cTAF may allow MCED tests to preferentially detect clinically significant cancers at early stages when outcomes are favorable and this may avoid overdiagnosis.