Recent Advances in Immunotherapy for Advanced Biliary Tract Cancer

OPINION STATEMENT

Biliary tract cancer (BTC) is a heterogeneous group of aggressive malignancies that arise from the epithelium of the biliary tract. Most patients present with locally advanced or metastatic disease at the time of diagnosis. For patients with unresectable BTC, the survival advantage provided by systemic chemotherapy was limited. Over the last decade, immunotherapy has significantly improved the therapeutic landscape of solid tumors. There is an increasing number of studies evaluating the application of immunotherapy in BTC, including immune checkpoint inhibitors (ICIs), cancer vaccines and adoptive cell therapy. The limited response to ICIs monotherapy in unselected patients prompted investigators to explore different combination therapy strategies. Early clinical trials of therapeutic cancer vaccination and adoptive cell therapy have shown encouraging clinical results. However, there still has been a long way to go via validation of therapeutic efficacy and exploration of strategies to increase the efficacy. Identifying biomarkers that predict the response to immunotherapy will allow a more accurate selection of candidates. This review will provide an up-to-date overview of the current clinical data on the role of immunotherapy, summarize the promising biomarkers predictive of the response to ICIs and discuss the perspective for future research direction of immunotherapy in advanced BTC.

Molecular Targets in Biliary Carcinogenesis and Implications for Therapy

Biliary tract cancers (BTCs) encompass a group of invasive carcinomas, including cholangiocarcinoma (intrahepatic, perihilar, or extrahepatic), and gallbladder carcinoma. Approximately 90% of patients present with advanced, unresectable disease and have a poor prognosis. The latest recommendation is to treat advanced or metastatic disease with gemcitabine and cisplatin, although chemotherapy has recorded modest survival benefits. Comprehension of the molecular basis of biliary carcinogenesis has resulted in experimental trials of targeted therapies in BTCs, with promising results. This review addresses the emerging role of targeted therapy in the treatment of BTCs. Findings from preclinical studies were reviewed and correlated with the outcomes of clinical trials that were undertaken to translate the laboratory discoveries.

IMPLICATIONS FOR PRACTICE

Biliary tract cancers are rare. Approximately 90% of patients present with advanced, unresectable disease and have a poor prognosis. Median overall and progression-free survival are 12 and 8 months, respectively. Because chemotherapy has recorded modest survival benefits, targeted therapies are being explored for personalized treatment of these cancers. A comprehensive review of targeted therapies in biliary tract cancers was undertaken to present emerging evidence from laboratory and/or molecular studies as they translate to clinical trials and outcomes. The latest evidence on this topic is presented to clinicians and practitioners to guide decisions on treatment of this disease.

Identification of active chemotherapy regimens in advanced biliary tract carcinoma: a review of chemotherapy trials in the past two decades

Biliary tract carcinoma is a rare malignancy. We performed a comprehensive analysis of published prospective clinical trials in advanced biliary tract carcinoma in an attempt to identify active regimens in this setting. We searched PubMed and abstracts presented at the American Society of Clinical Oncology, Gastrointestinal Cancer Symposium, European Society of Medical Oncology and European Cancer Organization conferences for clinical trials in this disease. We found 83 trials. The effect of gemcitabine on overall survival benefit showed a strong trend (p = 0.014) and an improvement in progression-free survival (p = 0.003). Gemcitabine-based regimens containing 5-fluorouracil showed a trend toward an improved overall survival (p = 0.047) relative to platinum agents. Our findings support gemcitabine as the chemotherapy backbone for the treatment of patients with cholangiocarcinoma. Gemcitabine plus 5-fluorouracil combinations warrant further investigations.

Cisplatin/gemcitabine or oxaliplatin/gemcitabine in the treatment of advanced biliary tract cancer: a systematic review

Cisplatin/gemcitabine association has been a standard of care for first-line regimen in advanced biliary tract cancer nevertheless oxaliplatin/gemcitabine regimen is frequently preferred. Because comparative effectiveness in clinical outcomes of cisplatin- versus oxaliplatin-containing chemotherapy is not available, a systematic review of studies assessing cisplatin/gemcitabine or oxaliplatin/gemcitabine chemotherapies in advanced biliary tract cancer was performed. Published studies evaluating cisplatin/gemcitabine or oxaliplatin/gemcitabine in advanced biliary tract cancer were included. Each study was weighted according to the number of patients included. The primary objective was to assess weighted median of medians overall survival (mOS) reported for both regimens. Secondary goals were to assess weighted median of medians progression-free survival (mPFS) and toxic effects were pooled and compared within each arm. Thirty-three studies involving 1470 patients were analyzed. In total, 771 and 699 patients were treated by cisplatin/gemcitabine and oxaliplatin/gemcitabine, respectively. Weighted median of mOS was 9.7 months in cisplatin group and 9.5 months in oxaliplatin group. Cisplatin-based chemotherapy was significantly associated with more grade 3 and 4 asthenia, diarrhea, liver toxicity, and hematological toxicity. Sensitivity analysis including only the studies with the standard regimen of cisplatin (25-35 mg/m(2) administered on days 1 and 8) showed that the weighted median of mOS increased from 9.7 to 11.7 months but Gem/CDDP regimen remained more toxic than Gemox regimen. These results suggest that the Gem/CDDP regimen with cisplatin (25-35 mg/m(2)) administered on days 1 and 8 is associated with survival advantage than Gemox regimen but with addition of toxicity.

Phase II study of gemcitabine, oxaliplatin in combination with panitumumab in KRAS wild-type unresectable or metastatic biliary tract and gallbladder cancer

BACKGROUND

Current data suggest that platinum-based combination therapy is the standard first-line treatment for biliary tract cancer. EGFR inhibition has proven beneficial across a number of gastrointestinal malignancies; and has shown specific advantages among KRAS wild-type genetic subtypes of colon cancer. We report the combination of panitumumab with gemcitabine (GEM) and oxaliplatin (OX) as first-line therapy for KRAS wild-type biliary tract cancer.

METHODS

Patients with histologically confirmed, previously untreated, unresectable or metastatic KRAS wild-type biliary tract or gallbladder adenocarcinoma with ECOG performance status 0-2 were treated with panitumumab 6 mg kg(-1), GEM 1000 mg m(-2) (10 mg m(-2) min(-1)) and OX 85 mg m(-2) on days 1 and 15 of each 28-day cycle. The primary objective was to determine the objective response rate by RECIST criteria v.1.1. Secondary objectives were to evaluate toxicity, progression-free survival (PFS), and overall survival.

RESULTS

Thirty-one patients received at least one cycle of treatment across three institutions, 28 had measurable disease. Response rate was 45% and disease control rate was 90%. Median PFS was 10.6 months (95% CI 5-24 months) and median overall survival 20.3 months (95% CI 9-25 months). The most common grade 3/4 adverse events were anaemia 26%, leukopenia 23%, fatigue 23%, neuropathy 16% and rash 10%.

CONCLUSIONS

The combination of gemcitabine, oxaliplatin and panitumumab in KRAS wild type metastatic biliary tract cancer showed encouraging efficacy, additional efforts of genetic stratification and targeted therapy is warranted in biliary tract cancer.

State-of-the-art in the management of locally advanced and metastatic gallbladder cancer

PURPOSE OF REVIEW

Gallbladder carcinoma (GBC), classified as a biliary tract cancer (BTC) along with intrahepatic and extrahepatic cholangiocarcinomas, is a rare disease in Western countries, but a highly prevalent disease in Chile, other countries in Latin America, India and Japan. It commonly presents at an advanced stage, and has limited therapeutic options. Cisplatin/gemcitabine has emerged as the first-line standard of care for patients with advanced BTCs, but the prognosis remains poor. Development of molecularly targeted therapies in advanced BTC remains challenging.

RECENT FINDINGS

Comprehension of the molecular events in gallbladder carcinogenesis may provide a novel targeted therapeutic approach, and early stage clinical trials with targeted therapies appear promising, although the relationship between subsets of patients with positive responses to therapy and tumor genetics requires further exploration. Recent developments in targeted therapeutics, directed against several key signalling pathways in BTC, including epidermal growth factor receptor, angiogenesis, and the mitogen-activated protein kinase pathway will be discussed, in addition to the potential application of prognostic factors and markers.

SUMMARY

The future therapeutic spectrum for BTC and GBC will likely encompass novel combinations of targeted therapies with cytostatics in scientifically and molecularly directed schedules, thus permitting fewer mechanisms of escape for tumor cells.

Current therapy and future directions in biliary tract malignancies

OPINION STATEMENT

Cancers of the biliary tree represent a rare group of diseases with a devastating impact on patients. Gallbladder cancer often is associated with cholelithiasis. Cholangiocarcinoma may arise in the setting of biliary inflammation, such as primary sclerosing cholangitis, but most commonly occurs in patients without a particular risk factor. Surgical removal of biliary cancer is essential for cure, but it is associated with a very high rate of recurrence and for many patients is not possible at the time of diagnosis. Although risk factors differ for each anatomic site, systemic treatment is generally similar. Various adjunctive therapies, such as radiation and embolization, have been investigated for biliary tract cancers with modest success and efforts are ongoing to understand how to optimize these tools. Retrospective series and pooled analysis suggest a benefit for adjuvant treatment following resection, but prospective data are limited. Ongoing and planned phase 3 trials should help to clarify the role of adjuvant chemotherapy and radiation. For advanced disease, chemotherapy improves quality of life and survival, and gemcitabine with cisplatin represents the standard of care. However, all patients ultimately progress on this therapy, so clinical trials of new and better agents are essential to expand the existing treatment options for patients.

Current status of chemotherapy for the treatment of advanced biliary tract cancer

Chemotherapy is indispensable for the treatment of advanced biliary tract cancer. Recently, reports regarding first-line chemotherapy have increased, and first-line chemotherapy treatment has become gradually more sophisticated. Gemcitabine and cisplatin combination therapy (or gemcitabine and oxaliplatin combination therapy) have become the standard of care for advanced biliary tract cancer. Oral fluoropyrimidines have also been shown to have good antitumor effects. Gemcitabine, platinum compounds, and oral fluoropyrimidines are now considered key drugs for the treatment of advanced biliary tract cancer. Several clinical trials using molecular targeted agents are also ongoing. Combination therapy using cytotoxic agents and molecular-targeted agents has been evaluated widely. However, reports regarding second-line chemotherapy remain limited, and it has not yet been clarified whether second-line chemotherapy can improve the prognosis of advanced biliary tract cancer. Thus, there is an urgent need to establish second-line standard chemotherapy treatment for advanced biliary tract cancer. Several problems exist when assessing the results of previous reports concerning advanced biliary tract cancer. In the present review, the current status of the treatment of advanced biliary tract cancer is summarized, and several associated problems are indicated. These problems should be solved to achieve more sophisticated treatment of advanced biliary tract cancer.