Phase I evaluation of telatinib, a vascular endothelial growth factor receptor tyrosine kinase inhibitor, in combination with irinotecan and capecitabine in patients with advanced solid tumors

Pyridazine as a privileged structure: An updated review on anticancer activity of pyridazine containing bioactive molecules

Identification of potent anticancer agents with high selectivity and low toxicity remains on the way to human health. Pyridazine featuring advantageous physicochemical properties and antitumor potential usually is regarded as a central core in numerous anticancer derivatives. There are several approved pyridazine-based drugs in the market and analogues currently going through different clinical phases or registration statuses, suggesting pyridazine as a promising drug-like scaffold. The current review is intended to provide a comprehensive and updated overview of pyridazine derivatives as potential anticancer agents. In particular, we focused on their structure-activity relationship (SAR) studies, design strategies, binding modes and biological activities in the hope of offering novel insights for further rational design of more active and less toxic anticancer drugs.

Near complete response to Pembrolizumab in microsatellite-stable metastatic sebaceous carcinoma

BACKGROUND

Sebaceous carcinoma is an aggressive adnexal skin tumor with a predilection for the eyelids and sebaceous glands of the head and neck.

CASE PRESENTATION

A 73 year-old man presented with confusion and was found to have widely disseminated sebaceous carcinoma with metastases to brain, lungs, liver, bowel, lymph nodes, and bone. Following initial treatment of the brain metastases with surgery he received post-operative radiosurgery. He then began systemic immunotherapy with pembrolizumab. After 6 months, he developed a near complete response to therapy by irRECIST and RECIST v.1.1. The response was associated with circulating CD8+ T cells with central memory (CM) and effector memory (EM) phenotype and mature CD16 + CD57+ NK cells. During treatment the patient developed adrenal insufficiency requiring high-dose systemic corticosteroids and later adrenal replacement therapy. After 12-months of follow-up he showed imaging evidence of progression in liver, mediastinum, and abdominal lymph nodes. Given persistent, strong PD-L1 expression he resumed pembrolizumab therapy and showed radiographic evidence of an ongoing response to therapy.

CONCLUSIONS

This is the first report describing objective clinical and radiographic responses following immunotherapy for widely metastatic sebaceous carcinoma. The dramatic therapeutic response to pembrolizumab was associated with peripheral blood circulating memory T cells and mature Natural Killer cells after 6 months (24 weeks) of therapy. This report supports prospective clinical trials of anti-PD1 checkpoint blockade for metastatic sebaceous carcinoma.

Gefitinib Synergizes with Irinotecan to Suppress Hepatocellular Carcinoma via Antagonizing Rad51-Mediated DNA-Repair

Chemotherapy is the only choice for most of the advanced hepatocellular carcinoma (HCC) patients, while few agents were available, making it an urgent need to develop new chemotherapy strategies. A phase II clinical trial suggested that the efficacy of irinotecan in HCC was limited due to dose-dependent toxicities. Here, we found that gefitinib exhibited synergistic activity in combination with SN-38, an active metabolite of irinotecan, in HCC cell lines. And the enhanced apoptosis induced by gefitinib plus SN-38 was a result from caspase pathway activation. Mechanistically, gefitinib dramatically promoted the ubiquitin–proteasome-dependent degradation of Rad51 protein, suppressed the DNA repair, gave rise to more DNA damages, and ultimately resulted in the synergism of these two agents. In addition, the increased antitumor efficacy of gefitinib combined with irinotecan was further validated in a HepG2 xenograft mice model. Taken together, our data demonstrated for the first time that the combination of irinotecan and gefitinib showed potential benefit in HCC, which suggests that Rad51 is a promising target and provides a rationale for clinical trials investigating the efficacy of the combination of topoisomerase I inhibitors and gefitinib in HCC.

Molecular targeted therapy in gastric cancer

Gastric cancer is one of the most common malignant tumors in China. Traditional treatments such as surgery, radiotherapy and chemotherapy not only have side effects, but the treatment efficiency is also poor. Molecular targeted therapy, due to its high efficiency, low toxicity, and high orientation, has been widely used in the treatment of gastric cancer. Targets applied in molecular targeted therapy of gastric cancer are mainly related to the cytokine and receptors that contribute to gastric cancer cell growth, including epidermal growth factor and its receptors, vascular endothelial growth factor and its receptors, epithelial cell adhesion molecules, insulin-like growth factor and its receptors, and molecules related to the cell cycle. This review focuses on molecular targeted treatment in gastric cancer.

Investigational therapies up to Phase II which target PDGF receptors: potential anti-cancer therapeutics

INTRODUCTION

The platelet-derived growth factor receptor (PDGFR) pathway has important functions in cell growth and, by overexpression or mutation, could also be a driver for tumor development. Moreover, PDGFR is expressed in a tumoral microenvironment and could promote tumorigenesis. With these biological considerations, the PDGFR pathway could be an interesting target for therapeutics. Currently, there are many molecules under development that target the PDGFR pathway in different types of cancer.

AREAS COVERED

In this review, the authors report the different molecules under development, as well as those approved albeit briefly, which inhibit the PDGFR pathway. Furthermore, the authors summarize their specificities, their toxicities, and their development.

EXPERT OPINION

Currently, most PDGFR kinase inhibitors are multikinase inhibitors and therefore do not simply target the PDGFR pathway. The development of more specific PDGFR inhibitors could improve drug efficacy. Moreover, selecting tumors harboring mutations or amplifications of PDGFR could improve outcomes associated with the use of these molecules. The authors believe that new technologies, such as kinome arrays or pharmacologic assays, could be of benefit to understanding resistance mechanisms and develop more selective PDGFR inhibitors.

Repositioning of Tyrosine Kinase Inhibitors as Antagonists of ATP-Binding Cassette Transporters in Anticancer Drug Resistance

The phenomenon of multidrug resistance (MDR) has attenuated the efficacy of anticancer drugs and the possibility of successful cancer chemotherapy. ATP-binding cassette (ABC) transporters play an essential role in mediating MDR in cancer cells by increasing efflux of drugs from cancer cells, hence reducing the intracellular accumulation of chemotherapeutic drugs. Interestingly, small-molecule tyrosine kinase inhibitors (TKIs), such as AST1306, lapatinib, linsitinib, masitinib, motesanib, nilotinib, telatinib and WHI-P154, have been found to have the capability to overcome anticancer drug resistance by inhibiting ABC transporters in recent years. This review will focus on some of the latest and clinical developments with ABC transporters, TKIs and anticancer drug resistance.

Targeted therapies in metastatic esophageal cancer: advances over the past decade

Esophageal cancer is one of the most aggressive malignancies of the upper aerodigestive tract. Despite advances in surgical techniques and multi-modality therapies, the 5-year survival rate remains poor (14%). Over the past decade, efforts have been focused on the field of drug development with the advancement of novel molecularly targeted therapeutic agents. These agents target a variety of cancer relevant pathways such as vascular endothelial growth factor (VEGF) or its receptor, the cyclooxygenase-2 (COX-2), epidermal growth factor receptor (EGFR), and mammalian target of rapamycin (mTOR) pathways. The number of approved targeted agents remains few, with HER-2 inhibitors leading the list for treatment of HER-2 expressing metastatic adenocarcinomas. Novel agents have not yet been widely explored in esophageal cancer. In this review, we will provide a concise and systematic overview of the development of novel targeted therapies currently under investigation for the treatment of metastatic esophageal disease.

Novel targets for VEGF-independent anti-angiogenic drugs

INTRODUCTION

In the last decades, the active research in the field of tumor angiogenesis led to the development of a class of agents providing an effective inhibition of neovessels formation through the blockade of VEGF-related pathways. More recently, the identification of several non-VEGF factors such as PDGF, FGF, HGF, angiopoietins, ALK1/endoglin, endothelis and ephrins involved in tumor angiogenesis have emphasized the need to develop agents targeting multiple pro-angiogenic pathways.

AREAS COVERED

This review aimed at summarizing the role of non-VEGF molecular pathways in targeting tumor angiogenesis. Preclinical and clinical data for investigational agents against non-VEGF targets have been reviewed emphasizing the role of combined inhibition strategies.

EXPERT OPINION

Besides the successful development of drugs providing a specific VEGF blockade, novel agents targeting alternative angiogenesis-related pathways are being tested. Although it seems that the potential clinical usefulness of these novel compounds have been not yet fully investigated, sunitinib, sorafenib, pazopanib and other multikinase inhibitors have certainly displayed encouraging results. A more in-depth clarification of anti-angiogenic agents is still needed, in order to design the best clinical setting and schedule for target-based agents and possibly anticipate potential tools to overcome the emerging issue of anti-angiogenic drug resistance.