Linifanib

In this study we demonstrate that linifanib, a multi-targeted receptor tyrosine kinase inhibitor, with a key urea containing pharmacophore, self-assembles into a hydrogel in the presence of low amounts of solvent. We demonstrate the role of the urea functional group and that of fluorine substitution on the adjacent aromatic ring in promoting self-assembly. We have also shown that linifanib has superior mechanical strength to two structurally related analogues and hence increased potential for localisation at an injection site for drug delivery applications.

OBJECTIVES: PARP inhibitors (PARPi) may provide an opportunity to gain selective killing of tumor cells which have deficiencies in cellular DNA repair systems. We previously demonstrated linifanib (ABT-869), a multi-receptor tyrosine kinase inhibitor of VEGF and PDGF receptor families, radiosensitized Head and Neck Squamous Cell Carcinoma cells (HNSCC) via inhibiting STAT3 activation. Given that STAT3 can modulate DNA damage response (DDR) pathway, in this study, we evaluate the effects of linifanib to enhance cytotoxicity with the PARPi, veliparib (ABT-888), in HNSCC.

Primary liver cancer is one of the commonest causes of death. Hepatocellular carcinoma (HCC) accounts for 90% of primary liver cancers. For patients with unresectable or metastatic HCC, conventional chemotherapy is of limited or no benefit. Sorafenib is the only systemic treatment to demonstrate a statistically significant but modest overall survival benefit, leading to an era of targeted agents. Many clinical trials of targeted drugs have been carried out with many more in progress. Some drugs like PTK787 showed potential benefits in the treatment of HCC. Despite these promising breakthroughs, patients with HCC still have a dismal prognosis. Recently, both a phase III trial of everolimus and a phase II clinical trial of trebananib failed to demonstrate effective antitumor activity in advanced HCC. Sorafenib still plays a pivotal role in advanced HCC, leading to further explorations to exert its maximum efficacy. Combinations targeted with chemotherapy or transarterial chemoembolization is now being tested and might bring about advances.

Advanced hepatocellular carcinoma (aHCC) is a complex disease beset by underlying liver dysfunction and high molecular heterogeneity. Sorafenib, introduced in 2007, is considered the standard systemic therapy for aHCC, yet only a minority of patients show objective evidence of a response radiologically, and median overall survival is still under 1 year. Other targeted drugs for the treatment of aHCC have failed to reach their primary endpoints of improved/non-inferior overall survival in comparison with sorafenib in recent phase 3 trials. Toxicity was a significant problem, raising the question as to whether outcomes in aHCC trials are being hindered by high levels of adverse events (AEs), particularly in populations with underlying cirrhosis. This is true of six recently failed phase 3 studies involving sunitinib, erlotinib, linifanib, brivanib (two trials), and everolimus, as well as ongoing phase 2 and 3 trials of other drugs that work through similar molecular pathways.