Current progress in systemic therapy for biliary tract cancers

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives

To overcome the poor prognosis of cholangiocarcinoma (CCA), highly targeted therapies, such as antibody-drug conjugates (ADCs), photodynamic therapy (PDT) with/without systemic chemotherapy, and experimental photoimmunotherapy (PIT), have been developed. Three preclinical trials have investigated the use of ADCs targeting specific antigens, namely HER2, MUC1, and glypican-1 (GPC1), for CCA. Trastuzumab emtansine demonstrated higher antiproliferative activity in CCA cells expressing higher levels of HER2. Similarly, "staphylococcal enterotoxin A-MUC1 antibody" and "anti-GPC1 antibody-monomethyl auristatin F" conjugates showed anticancer activity. PDT is effective in areas where appropriate photosensitizers and light coexist. Its mechanism involves photosensitizer excitation and subsequent reactive oxygen species production in cancer cells upon irradiation. Hematoporphyrin derivatives, temoporfin, phthalocyanine-4, talaporfin, and chlorine e6 derivatives have mainly been used clinically and preclinically in bile duct cancer. Currently, new forms of photosensitizers with nanotechnology and novel irradiation catheters are being developed. PIT is the most novel anti-cancer therapy developed in 2011 that selectively kills targeted cancer cells using a unique photosensitizer called "IR700" conjugated with an antibody specific for cancer cells. PIT is currently in the early stages of development for identifying appropriate CCA cell targets and irradiation devices. Future human and artificial intelligence collaboration has potential for overcoming challenges related to identifying universal CCA cell targets. This could pave the way for highly targeted therapies for CCA, such as ADC, PDT, and PIT.

Clinical outcomes of second‑line chemotherapy after gemcitabine and cisplatin plus S‑1 treatment for patients with advanced biliary tract cancer in the KHBO1401‑3A study

Since the completion of the KHBO1401 study, which evaluated the efficacy of the combination of gemcitabine (GEM) and cisplatin (GC) compared with GC plus S‑1 (GCS), GCS has become a standard chemotherapy for patients with advanced biliary tract cancer (BTC). However, there are currently no data revealing second‑line therapy options after GCS. The present study aimed to evaluate the survival outcomes of patients receiving second‑line chemotherapy for advanced BTC, refractory or intolerant to GCS, using data from the KHBO1401 study. Patients who received a second‑line treatment after GCS chemotherapy between July 2014 and February 2016 were retrospectively studied. Overall survival (OS) was calculated from the day of GCS treatment failure or the first day of second‑line chemotherapy to the final follow‑up date or until death from any cause. Among 83 patients refractory or intolerant to GCS chemotherapy, 51 (61%) received second‑line chemotherapy, including GCS (n=8), GC (n=15), GEM (n=6), GEM plus S‑1 (GS) (n=4) and S‑1 (n=18). The 6‑ and 12‑month OS rates were 66.7 and 44.4%, respectively, following second‑line chemotherapy, and 6.3 and 3.1%, respectively, in the best supportive care group (P<0.0001). In addition, the 12‑ and 24‑month OS rates were 59.3 and 36.2%, respectively, in the multidrug chemotherapy group, and 26.9 and 9.0%, respectively, in the single‑agent chemotherapy group (P=0.0191). These results suggested that second‑line combination chemotherapy is a viable treatment option for patients with advanced BTC that is refractory or intolerant to first‑line GCS therapy.

Novel Pharmacological Options in the Treatment of Cholangiocarcinoma: Mechanisms of Resistance

Simple Summary

Cholangiocarcinoma, a tumor derived from epithelial cells of the biliary tree, is characterized by a dismal prognosis. Its late diagnosis, which makes surgical resection not an option for most patients, and its marked refractoriness to standard chemotherapy, justify its high position in the rank of the most lethal cancers. Identifying specific druggable genetic alterations constitutes a promising alternative for the use of personalized targeted anticancer agents, and immunotherapy, or drugs able to interact with proteins involved in the crosstalk between cancer and immune cells, could also be an option in the future. However, it has also been observed that some patients fail to respond to these new therapies or after an initial response, the disease progresses. Therefore, understanding the mechanisms of pharmacoresistance is of utmost importance to design more effective treatments.

Abstract

Despite the crucial advances in understanding the biology of cholangiocarcinoma (CCA) achieved during the last decade, very little of this knowledge has been translated into clinical practice. Thus, CCA prognosis is among the most dismal of solid tumors. The reason is the frequent late diagnosis of this form of cancer, which makes surgical removal of the tumor impossible, together with the poor response to standard chemotherapy and targeted therapy with inhibitors of tyrosine kinase receptors. The discovery of genetic alterations with an impact on the malignant characteristics of CCA, such as proliferation, invasiveness, and the ability to generate metastases, has led to envisage to treat these patients with selective inhibitors of mutated proteins. Moreover, the hope of developing new tools to improve the dismal outcome of patients with advanced CCA also includes the use of small molecules and antibodies able to interact with proteins involved in the crosstalk between cancer and immune cells with the aim of enhancing the immune system’s attack against the tumor. The lack of effect of these new therapies in some patients with CCA is associated with the ability of tumor cells to continuously adapt to the pharmacological pressure by developing different mechanisms of resistance. However, the available information about these mechanisms for the new drugs and how they evolve is still limited.