Sorafenib tosylate in advanced kidney cancer: past, present and future

Hepatocellular cancer therapy in patients with HIV infection: Disparities in cancer care, trials enrolment, and cancer-related research

In the highly active antiretroviral therapy (HAART) era, hepatocellular carcinoma (HCC) is arising as a common late complication of human immunodeficiency virus (HIV) infection, with a great impact on morbidity and mortality. Though HIV infection alone may not be sufficient to promote hepatocarcinogenesis, the complex interaction of HIV with hepatitis is a main aspect influencing HCC morbidity and mortality.

Data about sorafenib effectiveness and safety in HIV-infected patients are limited, particularly for patients who are on HAART. However, in properly selected subgroups, outcomes may be comparable to those of HIV-uninfected patients. Scarce data are available for those other systemic treatments, either tyrosine kinase inhibitors, as well as immune checkpoint inhibitors (ICIs), which have been added to our therapeutic armamentarium. This review examines the influence of HIV infection on HCC development and natural history, summarizes main data on systemic therapies, offers some insight into possible mechanisms of T cell exhaustion and reversal of HIV latency with ICIs and issues about clinical trials enrollment. Nowadays, routine exclusion of HIV-infected patients from clinical trial participation is totally inappropriate, since it leaves a number of patients deprived of life-prolonging therapies.

Impact of Crystal Habit on the Dissolution Rate and In Vivo Pharmacokinetics of Sorafenib Tosylate

The dissolution rate is the rate-limiting step for Biopharmaceutics Classification System (BCS) class II drugs to enhance their in vivo pharmacokinetic behaviors. There are some factors affecting the dissolution rate, such as polymorphism, particle size, and crystal habit. In this study, to improve the dissolution rate and enhance the in vivo pharmacokinetics of sorafenib tosylate (Sor-Tos), a BCS class II drug, two crystal habits of Sor-Tos were prepared. A plate-shaped crystal habit (ST-A) and a needle-shaped crystal habit (ST-B) were harvested by recrystallization from acetone (ACN) and n-butanol (BuOH), respectively. The surface chemistry of the two crystal habits was determined by powder X-ray diffraction (PXRD) data, molecular modeling, and face indexation analysis, and confirmed by X-ray photoelectron spectroscopy (XPS) data. The results showed that ST-B had a larger hydrophilic surface than ST-A, and subsequently a higher dissolution rate and a substantial enhancement of the in vivo pharmacokinetic performance of ST-B.

Crystal Structure, Stability and Desolvation of the Solvates of Sorafenib Tosylate

In this study, three solvates of sorafenib tosylate were obtained from methanol, ethanol and n-methyl-2-pyrrolidone (NMP) after solvate screening and the effect of solvent on the formation of solvate was analyzed. The solvents with high value of polarity/dipolarity and appropriate hydrogen bond donor/acceptor propensity are more likely to form corresponding solvates. The crystal structures of the solvates were elucidated for the first time by using single crystal X-ray diffraction data. The analysis results indicate that methanol solvate and ethanol solvate are isostructural and hydrogen bonds could be formed between solvent molecules and sorafenib tosylate molecules. Hirshfeld surface analysis was used to research the interactions in the solvates, and the results reveal that the H···H, C···H/H···C and O···H/ H···O contacts play the vital role in molecular packing. In addition, three solvates were characterized by polarized light microscope, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The solvates show different thermodynamic stability in methanol +NMP and ethanol +NMP mixtures. Furthermore, the desolvation of solvates was studied by hot stage microscope and discussed.

Emerging tyrosine kinase inhibitors for the treatment of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is the fifth most diagnosed cancer in the world and the third leading cause of death. Unfortunately, when diagnosed two thirds of patients have an advanced disease for which only palliative treatment can be proposed and most likely systemic therapy. Areas covered: As of today only one systemic therapy is validated in the treatment of advanced HCC, a tyrosine kinase inhibitor (TKI): Sorafenib. Treatment options are therefore lacking. With the advent of Sorafenib other TKIs have been studied with some disappointing results. Many explanations can be found to the failure of these tested TKIs such as the underlying cirrhosis leading to rapidly serious adverse events, or trial design imperfections. Expert opinion: Taking into account these failures, new trials with more appropriate designs have led to recent success with multi-target TKIs (Regorafenib and Lenvatinib). This multi-target approach allows to overcome the molecular heterogeneity of advanced HCC which is associated with multiple simultaneously dysregulated signaling pathways. On the contrary, another lead is to study target a specific TKI such as c-MET inhibitors or TGFβR inhibitors in HCC sub-populations with promising results in early phase trials. These results will have to be validated in the ongoing phase III trials.

Renal effects of targeted anticancer therapies

The use of novel targeted anticancer agents has led to overall improvement in the prognosis of many patients affected by various malignancies, but has also been associated with an increased risk of poorly characterized toxic effects to different organs, including the kidneys. The high prevalence of kidney impairment in the general population complicates the issue further. Nephrologists most frequently work with patients with cancer when they are asked to investigate kidney function to assess the need for dose adjustments in anticancer therapy. A thorough knowledge of the renal safety profile of novel life-prolonging anticancer therapies, specific features of their metabolism, and pharmacokinetic and pharmacodynamic properties (under normal circumstances as well as in the setting of renal replacement therapy) is, therefore, necessary to preserve kidney function as far as possible and to ensure optimum treatment. In this Review we summarize the present knowledge of renal toxic effects from novel targeted anticancer agents and discuss whether the management of patients' treatment needs to be modified. We also advocate the development of a new onconephrology subspeciality.

Sorafenib neoadjuvant therapy in the treatment of high risk renal cell carcinoma

Objective

To evaluate the clinical efficacy of sorafenib as preoperative neoadjuvant therapy in patients with high risk renal cell carcinoma (RCC).

Materials and Methods

Clinical data of 18 patients with high risk RCC who received surgery done successfully after preoperative neoadjuvant therapy with sorafenib in Peking Union Medical College Hospital (PUMCH) from April 2007 to October 2013 have been reviewed and analyzed in this study.

Results

Among the 18 patients there were 13 male and 5 female, with a median age of 54.6 years. The objective response rate (ORR) of the operation on the selected patients is very high (94.4%), including 4 cases (22.2%) of partial response (PR) and 13 cases (72.2%) of stable disease (SD). After preoperative sorafenib treatment, the average tumor size of the 18 patients decreased from 7.8 cm (ranging from 3.6 to 19.2 cm) to 6.2 cm (ranging from 2.4 to 16.8 cm), and the median value of average tumor CT value decreased from 61HU to 52 HU. Among the 5 patients who had IVC tumor thrombi, the grades of tumor thrombi in 2 patients who were grade II before sorafenib treatment became grade I and grade 0 respectively, 2 patients of grade III both became grade II.

Conclusion

Preoperative neoadjuvant therapy with sorafenib for high risk RCC patients can significantly decrease primary tumor volume as well as tumor thrombus, which could help the nephron-sparing surgery (NSS) or radical nephrectomy to be done successfully.

Critical appraisal of sorafenib in the treatment of Chinese patients with renal cell carcinoma

Renal cell carcinoma (RCC) accounts for 3% of all malignancies, and is the most aggressive cancer of the genitourinary system. Metastatic RCC is naturally resistant to chemotherapy and radiotherapy, and immunotherapy is of little benefit. In recent years, the emergence of molecular-targeted therapies has largely changed the therapeutic approach to metastatic RCC. These novel multikinase inhibitors have now become first-choice therapy because of their activity in inhibiting both cell proliferation and tumor angiogenesis. Sorafenib is the first tyrosine kinase inhibitor found to be effective in treating patients with metastatic RCC. Due to its good efficacy and safety, this agent is recommended as both first-line and second-line therapy for metastatic RCC in the People's Republic of China. Sorafenib seems to be more effective in patients of Chinese ethnicity than in western patients, and is well tolerated with a manageable toxicity profile, even at higher dosages and when used in combination with other anticancer agents. Novel biomarkers for predicting the efficacy of sorafenib have potential clinical value for guiding individualized targeted therapy.

Sorafenib and HDAC inhibitors synergize with TRAIL to kill tumor cells

The present studies were designed to compare and contrast the abilities of TRAIL (death receptor agonist) and obatoclax (BCL-2 family inhibitor) to enhance sorafenib + HDAC inhibitor toxicity in GI tumor cells. Sorafenib and HDAC inhibitor treatment required expression of CD95 to kill GI tumor cells in vitro and in vivo. In cells lacking CD95 expression, TRAIL treatment, and to a lesser extent obatoclax, enhanced the lethal effects of sorafenib + HDAC inhibitor exposure. In hepatoma cells expressing CD95 a similar data pattern emerged with respect to the actions of TRAIL. Downstream of the death receptor the ability of TRAIL to enhance cell killing correlated with reduced AKT, ERK1/2, p70 S6K, and mTOR activity and enhanced cleavage of pro-caspase 3 and reduced expression of MCL-1 and BCL-XL. Over-expression of BCL-XL or MCL-1 or expression of dominant negative pro-caspase 9 protected cells from drug toxicity. Expression of activated AKT, p70 S6K, mTOR, and to a lesser extent MEK1EE also protected cells that correlated with maintained c-FLIP-s expression, reduced BIM expression, and increased BAD phosphorylation. In vivo sorafenib + HDAC inhibitor toxicity against tumors was increased in a greater than additive fashion by TRAIL. Collectively, our data argue that TRAIL, rather than obatoclax, is the most efficacious agent at promoting sorafenib + HDAC inhibitor lethality.

The VEGF pathway in cancer and disease: responses, resistance, and the path forward

Antiangiogenesis was proposed as a novel target for the treatment of cancer 40 years ago. Since the original hypothesis put forward by Judah Folkman in 1971, factors that mediate angiogenesis, their cellular targets, many of the pathways they signal, and inhibitors of the cytokines and receptors have been identified. Vascular endothelial growth factor (VEGF) is the most prominent among the angiogenic cytokines and is believed to play a central role in the process of neovascularization, both in cancer as well as other inflammatory diseases. This article reviews the biology of VEGF and its receptors, the use of anti-VEGF approaches in clinical disease, the toxicity of these therapies, and the resistance mechanisms that have limited the activity of these agents when used as monotherapy.

Clinical perspectives for irreversible tyrosine kinase inhibitors in cancer

Irreversible inhibitors provide potent and selective inhibition of tyrosine kinase enzymes. Use of such inhibitors has proved promising in overcoming the tumor resistance encountered with reversible tyrosine kinase inhibitors. Irreversible inhibitors inactivate their protein target through covalent interaction with a nucleophilic cysteine residue within the nucleotide binding pocket of the kinase domain. Different irreversible tyrosin kinase inhibitors directed against epidermal growth factor receptor (EGFR), Bruton's tyrosine kinase (BTK), vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor tyrosine kinase (FGFR) have been developed and some of them have been employed clinically as anticancer agents. This review focuses on recent preclinical and clinical progress with currently available irreversible tyrosine kinase inhibitors. The chemical structures of the candidates, structure-activity relationships, biological activities and results of current clinical investigations are described.

Immunological effects of multikinase inhibitors for kidney cancer: a clue for integration with cellular therapies?

The multikinase inhibitors Sunitinib and Sorafenib not only inhibit angiogenesis and tumor growth, but also have the potential of interacting with the function of the immune system.

Presently available data seem to suggest that Sorafenib may exert immune suppressive effects, whilst the effects of Sunitinib are not so clear, being immune stimulatory in the vast majority - but not all - the studies reported.

Trials of combination of these multikinase inhibitors with different types of immune manipulation - and cellular therapies in particular - should be rationally designed taking into account all these complex effects, which ultimately deserve further insights.

Cerebrovascular accidents associated with sorafenib in hepatocellular carcinoma

Sorafenib is an oral angiogenetic multikinase inhibitor approved in the treatment of renal and hepatocellular carcinoma. Bleeding and venous thrombotic events have been described with angiogenetic agents but cerebrovascular accidents are rarely reported. We report two cases of patients with hepatocellular carcinoma who developed a cerebrovascular accident while on sorafenib. Neither patient had any risk factors for the cerebrovascular events apart from gender and age in the second patient. Laboratory data were noncontributory. The head CT scan did not reveal acute abnormalities. No hemodynamically significant stenosis was visible in the carotid ultrasound, and the echocardiogram showed normal size of the heart chambers and normal systolic function of the left ventricle. Sorafenib was discontinued in both cases. Physicians should monitor patients receiving sorafenib for neurologic symptoms, and in the absence of other etiology, prompt discontinuation of this drug should be considered.

Clinical experience and critical evaluation of the role of sorafenib in renal cell carcinoma

Renal cell carcinoma (RCC) is a common malignancy worldwide with approximately 95,000 new cases per year and ranks as the sixth cause of cancer deaths. Until recently, the slightly active and very toxic cytokines were available for patients with advanced RCC. Advances have been made in understanding the molecular biology of renal cancer. The introduction of targeted agents has led to promising possibilities for treating these highly vascularized tumors. Angiogenesis inhibition is likely to represent the main potential therapeutic target. Sorafenib is an oral multikinase inhibitor with activity against tyrosine kinase receptors that are responsible for blood vessel development and has shown to be active in treating advanced RCC. In this review, we summarize the pharmacology, mode of action, pharmacokinetics, and safety of sorafenib use in therapy for advanced RCC.

Receptor tyrosine kinase and downstream signalling analysis in diffuse malignant peritoneal mesothelioma

Our aim was to assess the activation profile of EGFR, PDGFRB and PDGFRA receptor tyrosine kinases (RTK) and their downstream effectors in a series of cryopreserved diffuse malignant peritoneal mesothelioma (DMPM) surgical specimens to discover the targets for drug inhibition. We also made a complementary analysis of the cytotoxic effects of some kinase inhibitors on the proliferation of the human peritoneal mesothelioma STO cell line. We found the expression/phosphorylation of EGFR and PDGFRB in most of the tumours, and PDGFRA activation in half. The expression of the cognate ligands TGF-α, PDGFB and PDGFA in the absence of RTK mutation and amplification suggested the presence of an autocrine/paracrine loop. There was also evidence of EGFR and PDGFRB co-activation. RTK downstream signalling analysis demonstrated the activation/expression of ERK1/2, AKT and mTOR, together with S6 and 4EBP1, in almost all the DMPMs. No KRAS/BRAF mutations, PI3KCA mutations/amplifications or PTEN inactivation were observed. Real-time polymerase chain reaction revealed the decreased expression of TSC1 c-DNA in half of the tumours. In vitro cytotoxicity studies showed the STO cell line to be resistant to gefitinib and sensitive to sequential treatment with RAD001 and sorafenib; these findings were consistent with the presence of the KRAS mutation G12D in these cells although it was not detectable in the original tumour. Our results highlight the ligand-dependent activation and co-activation of EGFR and PDGFRB, as well as a connection between these activated RTKs and the downstream mTOR pathway, thus supporting the role of combined treatment with RTK and mTOR inhibitors in DMPM.