Allyl phenyl selenides as H2O2 acceptors to develop ROS-responsive theranostic prodrugs

Reactive oxygen species (ROS)-responsive prodrugs have received significant attention due to their capacity to target tumors to relieve the side effects caused by chemotherapy. Herein, a series of novel H₂O₂-activated theranostic prodrugs (CPTSe1-CPTSe7) were developed containing allyl phenyl selenide moieties as H₂O₂ acceptors. Compared with conventional boronate ester-based prodrug CPT-B, CPTSe1 was more stable in human plasma and showed a more complete release of camptothecin (CPT) in H₂O₂ inducing experiment. The selectively activated fluorescence signals of CPTSe1 in tumor cells make it useful for real-time monitoring of CPT release and H₂O₂ detection. Furthermore, excellent selectivity of CPTSe1 was achieved for tumor cells over normal cells. Our results provide a new platform for the development of H₂O₂-responsive theranostic prodrugs.

Precision approaches for cholangiocarcinoma: Progress in clinical trials and beyond

INTRODUCTION

Although a relatively uncommon tumor, the incidence of intrahepatic cholangiocarcinoma is rising globally. Unfortunately, most patients are diagnosed with locally advanced or metastatic disease with poor prognosis. Strategies targeting genomic alterations and incorporation of precision medicine will represent a new therapeutic avenue for these patients.

AREAS COVERED

In this review article we addressed clinical trials in cholangiocarcinoma with FGFR, IDH, BRAF and ErbB2 targeted therapies. We also reviewed mechanisms of resistance to precision medicine and possible future strategies to overcome clonal evolution. Articles selected for this review were based on reported studies indexed in PubMed (2010-2021).

EXPERT OPINION

Pemigatinib, infigratinib and futibatinib could eventually be incorporated in the landscape of first-line systemic treatment for advanced cholangiocarcinoma with FGFR2 fusions or rearrangements after the ongoing phase III trials. Circulating tumor DNA could be used as a dynamic tool for evaluating mechanisms of resistance and prediction of response in patients treated with directed therapy.

Optimal Management of Patients with Advanced or Metastatic Cholangiocarcinoma: An Evidence-Based Review

Cholangiocarcinomas are rare tumors originating at any point along the biliary tree. These tumors often pose significant challenges for diagnosis and treatment, and often carry a poor prognosis. However, in recent years, studies have identified significant molecular heterogeneity with up to 50% of tumors having detectable mutations, leading to the guideline recommendations for molecular testing as part of the diagnostic workup for these tumors. In addition, better classification of these tumors and understanding of their biology has led to new drugs being approved for treatment of this resistant tumor. This manuscript will provide a comprehensive review of the epidemiology, risk factors, diagnostic approach, molecular classification, and treatment options for patients with advanced cholangiocarcinomas.

Current options and future directions of systemic therapy for advanced biliary tract cancer

Biliary tract cancers (BTCs) are aggressive tumors arising from different portions of the biliary tree and classified according to the anatomical location in intrahepatic (i) cholangiocarcinoma (CCA, iCCA), perihilar CCA (pCCA), and distal CCA (dCCA), gallbladder cancer (GBC), and ampulla of Vater cancer (AVC). Due to their silent behavior, BTCs are frequently diagnosed at advanced stages when the prognosis is poor. The available chemotherapeutic options are palliative and unfortunately, most patients will die from their disease between 6 and 18 months from diagnosis. However, over the last decade, amounting interest has been posed on the genomic landscape of BTCs and deep-sequencing studies have identified different potentially actionable driver mutations. Hence, the promising results of the early phase clinical studies with targeted agents against isocitrate dehydrogenase (IDH) 1 mutation or fibroblast growth factor (FGF) receptor(FGFR) 2 aberrations inintrahepatic tumors, and other agents against humanepidermal growth factor receptor (HER) 2 overexpression/mutations, neurotrophic tyrosine receptor kinase (NTRK) fusions or B-type Raf kinase (BRAF) mutations across different subtypes of BTCs, have paved the way for a “precision medicine” strategy for BTCs. Moreover, despite the modest results when used as monotherapy, beyond microsatellite instability-high (MSI-H) tumors, immune checkpoint inhibitors are being evaluated in combination with platinum-based chemotherapy, possibly further expanding the therapeutic landscape of advanced BTCs. This review aims to provide an overview of the approved systemic therapies, the promising results, and the ongoing studies to explore the current and future directions of advanced BTC systemic treatment.

Molecular Subtypes and Precision Oncology in Intrahepatic Cholangiocarcinoma

Cholangiocarcinomas (CCAs) are the second-most common primary liver cancers. CCAs represent a group of highly heterogeneous tumors classified based on anatomical localization into intra- (iCCA) and extrahepatic CCA (eCCA). In contrast to eCCA, the incidence of iCCA is increasing worldwide. Curative treatment strategies for all CCAs involve oncological resection followed by adjuvant chemotherapy in early stages, whereas chemotherapy is administered at advanced stages of disease. Due to late diagnosis, high recurrence rates, and limited treatment options, the prognosis of patients remains poor. Comprehensive molecular characterization has further revealed considerable heterogeneity and distinct prognostic and therapeutic traits for iCCA and eCCA, indicating that specific treatment modalities are required for different subclasses. Several druggable alterations and oncogenic drivers such as fibroblast growth factor receptor 2 gene fusions and hotspot mutations in isocitrate dehydrogenase 1 and 2 mutations have been identified. Specific inhibitors have demonstrated striking antitumor activity in affected subgroups of patients in phase II and III clinical trials. Thus, improved understanding of the molecular complexity has paved the way for precision oncological approaches. Here, we outline current advances in targeted treatments and immunotherapeutic approaches. In addition, we delineate future perspectives for different molecular subclasses that will improve the clinical care of iCCA patients.

Development of Possible Next Line of Systemic Therapies for Gemcitabine-Resistant Biliary Tract Cancers: A Perspective from Clinical Trials

Biliary tract cancer (BTC) compromises a heterogenous group of tumors with poor prognoses. Curative surgery remains the first choice for localized disease; however, most BTC patients have had unresectable or metastatic disease. The gold standard therapy for these patients is chemotherapy with gemcitabine and cisplatin. There are no consensus guidelines for standard treatment in a second-line setting, although the data of the ABC-06 trial showed a slight survival benefit from oxaliplatin and 5-fluorouracil combination chemotherapy. Recent progress in comprehensive genomic profiling for advanced BTC (ABTC) has helped to clarify tumorigenesis and facilitate the coming era of precision medicine. Generally, targeted agents fail to show significant clinical benefits in unselected populations. Only fibroblast growth factor receptor 2 (FGFR2) fusion and isocitrate dehydrogenase (IDH)- and BRAF mutation-enriched populations have survival benefits from the corresponding inhibitors. Several interesting targeted agents for monotherapies or combination therapies with other compounds are currently ongoing or recruiting. Here, we review the published data from clinical trials of second-line therapies after the failure of gemcitabine-based chemotherapy in ABTC. The results were stratified by different genetic alternations, as well as by chemotherapy, targeted therapy and immunotherapy.

Biliary Tract Cancers: Molecular Heterogeneity and New Treatment Options

Most patients with biliary tract cancer (BTC) are diagnosed with advanced disease, relapse rates are high in those undergoing surgery and prognosis remains poor, while the incidence is increasing. Treatment options are limited, and chemotherapy is still the standard of care in both adjuvant and advanced disease setting. In recent years, different subtypes of BTC have been defined depending on the anatomical location and genetic and/or epigenetic aberrations. Especially for intrahepatic cholangiocarcinoma (iCCA) novel therapeutic targets have been identified, including fibroblast growth factor receptor 2 gene fusions and isocitrate dehydrogenase 1 and 2 mutations, with molecularly targeted agents having shown evidence of activity in this subgroup of patients. Additionally, other pathways are being evaluated in both iCCA and other subtypes of BTC, alongside targeting of the immune microenvironment. The growing knowledge of BTC biology and molecular heterogeneity has paved the way for the development of new therapeutic approaches that will completely change the treatment paradigm for this disease in the near future. This review provides an overview of the molecular heterogeneity of BTC and summarizes new targets and emerging therapies in development. We also discuss resistance mechanisms, open issues, and future perspectives in the management of BTC.

Systemic treatment options for advanced biliary tract carcinoma

Advanced biliary tract cancers (BTC) include a diverse collection of rare and heterogenous tumors with poor prognosis. The combination of gemcitabine and cisplatin is the established first-line therapy for advanced BTC. There are no accepted standard treatments in the second line setting, though there are several ongoing clinical trials that implement chemotherapy as a therapeutic strategy. The understanding of the molecular landscape of BTC has offered hope of targeted therapies to the identified actionable genomic aberrations, such as FGFR2 gene fusions, mutations of IDH1/2, HER2, BRAC1/2 and BRAF. Pembigatinib has become the first approved targeted therapy for BTC with FGFR2 fusion or other rearrangements. Recent immunotherapy has opened new therapy avenues in BTC with pembrolizumab approved for either microsatellite instability high (MSI-H) or DNA mismatch repair deficient (dMMR) advanced solid tumors, including BTC. The combination of immunotherapy with other modalities is currently being evaluated in different clinical trials, since single agent immunotherapy appears to provide modest benefits in advanced BTC. In this review, we summarize the current status of treatment options, including systemic chemotherapy, targeted therapy, immunotherapy, and various combinations in advanced BTC.