Phase I study to determine the safety and pharmacokinetics of the novel Raf kinase and VEGFR inhibitor BAY 43-9006, administered for 28 days on/7 days off in patients with advanced, refractory solid tumors

New pyrazolylindolin-2-one based coumarin derivatives as anti-melanoma agents: design, synthesis, dual BRAFV600E/VEGFR-2 inhibition, and computational studies

Malignant melanoma is the most invasive skin cancer with the highest risk of death. The inhibition of BRAFV600E appears relevant for overcoming secondary resistance developed during melanoma treatment. BRAFV600E triggers angiogenesis via modification of the expression of angiogenic inducers, which play a crucial role in the metastasis of melanoma. Accordingly, the dual inhibition of the BRAFV600E/VEGFR-2 signaling pathway is considered a rational approach in the design of anti-melanoma candidates. In this study, a new class of pyrazolylindolin-2-one linked coumarin derivatives as dual BRAFV600E/VEGFR-2 inhibitors targeting A375 melanoma cells was designed. Target compounds were tailored to occupy the pockets of BRAFV600E and VEGFR-2. Most of the synthesized compounds demonstrated potent mean growth inhibitory activity against A375 cells. Compound 4j was the most active cytotoxic derivative, displaying an IC50 value at a low micromolar concentration of 0.96 μM with a significant safety profile. Moreover, 4j showed dual potent inhibitory activity against BRAFV600E and VEGFR-2 (IC50 = 1.033 and 0.64 μM, respectively) and was more active than the reference drug sorafenib. Furthermore, derivative 4j caused significant G0/G1 cell cycle arrest, induced apoptosis, and inhibited the migration of melanoma cells. Molecular docking showed that compound 4j achieved the highest ΔG value of -9.5 kcal mol-1 against BRAFV600E and significant ΔG of -8.47 kcal mol-1 against VEGFR-2. Furthermore, the structure-activity relationship study revealed that TPSA directly contributed to the anticancer activity of the tested compounds.

Discovery, Synthesis, and Evaluation of Novel Dual Inhibitors of a Vascular Endothelial Growth Factor Receptor and Poly(ADP-Ribose) Polymerase for BRCA Wild-Type Breast Cancer Therapy

Poly(ADP-ribose) polymerase (PARP) inhibitors have been approved for the treatment of breast cancer (BC) with breast cancer susceptibility (BRCA) gene mutation. Leveraging new synthetic lethal interactions may be an effective way to broaden the indication of PARP inhibitors for BC patients with wild-type BRCA. Vascular endothelial growth factor receptor (VEGFR)-mediated suppression of angiogenesis has been reported to improve the sensitivity of wild-type BRCA cells to PARP inhibitors through synthetic lethality. Herein, we reported the conjugation of a PARP inhibitor with a VEGFR inhibitor pharmacophore to construct dual VEGFR and PARP inhibitors. The most potent compound 14b is identified to exert promising activities against VEGFR and PARP in the nanomolar range and possesses significant in vitro and in vivo antitumor and antimetastasis features. It also presented a favorable pharmacokinetic characteristics in rats with an oral bioavailability of 60.1%. Collectively, 14b may be a promising therapeutic agent of BRCA wild-type BC.

Synthesis, characterization, and antiproliferative evaluation of novel sorafenib analogs for the treatment of hepatocellular carcinoma

Cancer is a disease triggered by an uncontrolled proliferation of a cluster of cells, typically originating from a single cell. Sorafenib, a widely utilized pharmaceutical, has limitations in clinical use due to pharmacokinetic challenges and the development of resistance mechanisms. This investigation aimed to synthesize new sorafenib analogs and evaluated their activity against HepG2 cell lines, specifically targeting hepatocellular carcinoma (HCC). Seven sorafenib analogs were synthesized and identified by Fourier-transform infrared spectroscopy and 1H-NMR spectra. Cytotoxicity of the analogs was assessed on the human HepG2 cancer cell line by (3-(4, 5-dimethylthazolk-2-yl)-2, 5-diphenyl tetrazolium bromide) colorimetric assay. Results revealed that among the studied compounds, 4b exhibited the most pronounced cytotoxicity against cancer cells, surpassing even the efficacy of sorafenib. This suggested that small substitutions on the NH moiety play a crucial role in the activity against the human HepG2 liver cancer cell line. These findings provide valuable insights for the development of potential anticancer-targeting HCC.

The potential of RAS/RAF/MEK/ERK (MAPK) signaling pathway inhibitors in ovarian cancer: A systematic review and meta-analysis

BACKGROUND

The RAS/RAF/MEK/ERK (MAPK) pathway plays a role in ovarian carcinogenesis. Low-grade serous ovarian carcinoma (LGSOC) frequently harbors activating MAPK mutations. MAPK inhibitors have been used in small subsets of ovarian carcinoma (OC) patients to control tumor growth. Therefore, we performed a meta-analysis to evaluate the effectiveness of MAPK inhibitors in OC patients. We aimed to determine the clinical benefit rate (CBR), the subgroup of MAPK inhibitors with the best CBR and overall response rate (ORR), and the most common adverse events.

METHODS

We conducted a search in PubMed, Embase via Ovid, the Cochrane library and clinicaltrials.gov on studies evaluating the efficacy of single MAPK pathway inhibition with MAPK pathway inhibitors in OC patients. Our primary outcome included the CBR, defined by the proportion of patients with stable disease (SD), complete (CR) and partial response (PR). Secondary outcomes included the ORR (including PR and CR) and grade 3 and 4 adverse events. Meta-analysis was performed using a random-effects model.

RESULTS

We included nine studies with a total of 319 OC patients, for which we determined a pooled CBR of 63% (95%-CI 39-84%, I² = 92%). Combined treatment with Raf- and MEK inhibitors in in BRAF^v600 mutated LGSOC (n = 6) had the greatest efficacy with a CBR of 100% and ORR of 83%. MEK inhibitors had the best efficacy as a single agent. Subgroup analysis by tumor histology demonstrated a significantly higher CBR and ORR in patients with LGSOC, with a pooled CBR and ORR of 87% (95%-CI 81-92%, I² = 0%) and 27% (95%-CI 10-48%, I² = 77%) respectively. Adverse events of grade 3 or higher were reported frequently: 123 in 167 patients.

CONCLUSIONS

MEK inhibitors are the most promising single agents in (LGS)OC. However, dual MAPK pathway inhibition should be considered in patients with a BRAF^v600 mutation, or non-mutated OC with depleted treatment options due indications of higher efficacy and tolerable toxicity profiles.

Temporal Characteristics of Adverse Events of Tivozanib and Sorafenib in Previously Treated Kidney Cancer

INTRODUCTION

Tivozanib, vascular endothelial growth factor receptor inhibitor, met the primary endpoint of improved progression free survival compared to sorafenib in the phase 3 TIVO-3 study in patients with previously treated metastatic renal cell carcinoma. In this study we sought to understand the temporal characteristics of treatment related adverse events (TRAEs) and frequency and timing of the dose modifications.

MATERIALS AND METHODS

In this open label, randomized, phase 3 TIVO-3 study, previously treated patients with a diagnosis of metastatic renal cell carcinoma and with measurable disease were included. Patients were randomized to receive either tivozanib 1.5 mg orally once daily in 4-week cycles or sorafenib 400 mg orally twice daily continuously. Based on updated safety analysis data (cutoff date of August 15, 2019), time to onset of the most commonly reported TRAEs, duration of toxicity, rate of dose modifications was calculated for each treatment arm.

RESULTS

Overall, 350 patients were randomly assigned to receive tivozanib or sorafenib;173 patients from the tivozanib arm and 170 patients from the sorafenib arm were included in this analysis. Patients received a median of 11.9 cycles (336 days) and 6.7 cycles (192 days) of tivozanib and sorafenib, respectively. Dose reductions, interruptions and treatment discontinuations were 25%, 50%, and 21%, and 39%, 50%, and 30% in the tivozanib and sorafenib arms, respectively, with a longer time to onset of TRAEs in the tivozanib arm.

CONCLUSION

Tivozanib was associated with less TRAEs, fewer dose modifications, a longer time to onset and a shorter duration of TRAEs compared to sorafenib.

BAYESIAN HIERARCHICAL RANDOM-EFFECTS META-ANALYSIS AND DESIGN OF PHASE I CLINICAL TRIALS

We propose a curve-free random-effects meta-analysis approach to combining data from multiple phase I clinical trials to identify an optimal dose. Our method accounts for between-study heterogeneity that may stem from different study designs, patient populations, or tumor types. We also develop a meta-analytic-predictive (MAP) method based on a power prior that incorporates data from multiple historical studies into the design and conduct of a new phase I trial. Performances of the proposed methods for data analysis and trial design are evaluated by extensive simulation studies. The proposed random-effects meta-analysis method provides more reliable dose selection than comparators that rely on parametric assumptions. The MAP-based dose-finding designs are generally more efficient than those that do not borrow information, especially when the current and historical studies are similar. The proposed methodologies are illustrated by a meta-analysis of five historical phase I studies of Sorafenib, and design of a new phase I trial.

Feasibility of therapeutic drug monitoring of sorafenib in patients with liver or thyroid cancer

INTRODUCTION

Sorafenib is a tyrosine-kinase inhibitor approved for the treatment of renal cell carcinoma, hepatocellular carcinoma, thyroid carcinoma, and desmoid fibromatosis. As high inter-individual variability exists in exposure, there is a scientific rationale to pursue therapeutic drug monitoring (TDM). We investigated the feasibility of TDM in patients on sorafenib and tried to identify sub-groups in whom pharmacokinetically (PK) guided-dosing might be of added value.

METHODS

We included patients who started on sorafenib (between October 2017 and June 2020) at the recommended dose of 400 mg BID or with a step-up dosing schedule. Plasma trough levels (C_trough) were measured at pre-specified time-points. Increasing the dose was advised if C_trough was below the target of 3750 ng/mL and toxicity was manageable.

RESULTS

A total of 150 samples from 36 patients were collected. Thirty patients (83 %) had a C_trough below the prespecified target concentration at a certain time point during treatment. Toxicity from sorafenib hampered dosing according to target C_trough in almost half of the patients. In 11 patients, dosing was adjusted based on C_trough. In three patients, this resulted in an adequate C_trough without additional toxicity four weeks after the dose increase. In the remaining eight patients, dose adjustment based on C_trough did not result in a C_trough above the target or caused excessive toxicity.

CONCLUSIONS

TDM for sorafenib is not of added value in daily clinical practice. In most cases, toxicity restricts the possibility of dose escalations.

Recent progress on vascular endothelial growth factor receptor inhibitors with dual targeting capabilities for tumor therapy

Vascular endothelial growth factor receptors (VEGFRs) are a family of receptor protein tyrosine kinases that play an important role in the regulation of tumor-induced angiogenesis. Currently, VEGFR inhibitors have been widely used in the treatment of various tumors. However, current VEGFR inhibitors are limited to a certain extent due to limited clinical efficacy and potential toxicity, which hinder their clinical application. Thus, the development of new strategies to improve the clinical outcomes and minimize the toxic effects of VEGFR inhibitors is required. Given the synergistic effect of VEGFR and other therapies in tumor development and progression, VEGFR dual-target inhibitors are becoming an attractive approach due to their favorable pharmacodynamics, low toxicity, and anti-resistant effects. This perspective provides an overview of the development of VEGFR dual-target inhibitors from multiple aspects, including rational target combinations, drug discovery strategies, structure–activity relationships and future directions.

A straightforward meta-analysis approach for oncology phase I dose-finding studies

Phase I early-phase clinical studies aim at investigating the safety and the underlying dose-toxicity relationship of a drug or combination. While little may still be known about the compound's properties, it is crucial to consider quantitative information available from any studies that may have been conducted previously on the same drug. A meta-analytic approach has the advantages of being able to properly account for between-study heterogeneity, and it may be readily extended to prediction or shrinkage applications. Here we propose a simple and robust two-stage approach for the estimation of maximum tolerated dose(s) utilizing penalized logistic regression and Bayesian random-effects meta-analysis methodology. Implementation is facilitated using standard R packages. The properties of the proposed methods are investigated in Monte Carlo simulations. The investigations are motivated and illustrated by two examples from oncology.

Borrowing historical information to improve phase I clinical trials using meta-analytic-predictive priors

Multiple phase I clinical trials may be performed to determine specific maximum tolerated doses (MTD) for specific races or cancer types. In these situations, borrowing historical information has potential to improve the accuracy of estimating toxicity rate and increase the probability of correctly targeting MTD. To utilize historical information in phase I clinical trials, we proposed using the Meta-Analytic-Predictive (MAP) priors to automatically estimate the heterogeneity between historical trials and give a relatively reasonable amount of borrowed information. We then applied MAP priors in some famous phase I trial designs, such as the continual reassessment method (CRM), Keyboard design and Bayesian optimal interval design (BOIN), to accomplish the process of dose finding. A clinical trial example and extended simulation studies show that our proposed methods have robust and efficient statistical performance, compared with those designs which do not consider borrowing information.

Kidney Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Kidney Cancer focus on the screening, diagnosis, staging, treatment, and management of renal cell carcinoma (RCC). Patients with relapsed or stage IV RCC typically undergo surgery and/or receive systemic therapy. Tumor histology and risk stratification of patients is important in therapy selection. The NCCN Guidelines for Kidney Cancer stratify treatment recommendations by histology; recommendations for first-line treatment of ccRCC are also stratified by risk group. To further guide management of advanced RCC, the NCCN Kidney Cancer Panel has categorized all systemic kidney cancer therapy regimens as "Preferred," "Other Recommended Regimens," or "Useful in Certain Circumstances." This categorization provides guidance on treatment selection by considering the efficacy, safety, evidence, and other factors that play a role in treatment selection. These factors include pre-existing comorbidities, nature of the disease, and in some cases consideration of access to agents. This article summarizes surgical and systemic therapy recommendations for patients with relapsed or stage IV RCC.

Phase 1 study of sorafenib and irinotecan in pediatric patients with relapsed or refractory solid tumors

BACKGROUND

Sorafenib,an orally bioavailable, multitarget tyrosine kinase inhibitor, and irinotecan, a topoisomerase I inhibitor, have demonstrated activity in pediatric and adult malignancies. We evaluated the toxicity, pharmacokinetic (PK), and pharmacogenomic (PGX) profile of sorafenib with irinotecan in children with relapsed or refractory solid tumors and assessed the feasibility of incorporating patient-reported outcome (PRO) measures as an adjunct to traditional endpoints.

METHODS

Sorafenib, continuous oral twice daily dosing, was administered with irinotecan, orally, once daily days 1-5, repeated every 21 days (NCT01518413). Based on tolerability, escalation of sorafenib followed by escalation of irinotecan was planned. Three patients were initially enrolled at each dose level. Sorafenib and irinotecan PK analyses were performed during cycle 1. PRO measurements were collected during cycles 1 and 2.

RESULTS

Fifteen patients were evaluable. Two of three patients at dose level 2 experienced dose-limiting toxicity (DLT), grade 3 diarrhea, and grade 3 hyponatremia. Therefore, dose level 1 was expanded to 12 patients and two patients had DLT, grade 4 thrombocytopenia, grade 3 elevated lipase. Nine of 15 (60%) patients had a best response of stable disease with four patients receiving ≥6 cycles.

CONCLUSIONS

The recommended dose for pediatric patients was sorafenib 150 mg/m² /dose twice daily with irinotecan 70 mg/m² /dose daily × 5 days every 21 days. This oral outpatient regimen was well tolerated and resulted in prolonged disease stabilization. There were no significant alterations in the PK profile of either agent when administered in combination. Patients were willing and able to report their subjective experiences with this regimen.

Magnetic implants in vivo guiding sorafenib liver delivery by superparamagnetic solid lipid nanoparticles

HYPOTHESIS

Solid lipid nanoparticles (SLNs), co-encapsulating superparamagnetic iron oxide nanoparticles and sorafenib, have been exploited for magnetic-guided drug delivery to the liver. Two different magnetic configurations, both comprising two small magnets, were under-skin implanted to investigate the effect of the magnetic field topology on the magnetic SLNP accumulation in liver tissues. A preliminary simulation analysis was performed to predict the magnetic field topography for each tested configuration.

EXPERIMENTS

SLNs were prepared using a hot homogenization approach and characterized using complementary techniques. Their in vitro biological behavior was assessed in HepG-2 liver cancer cells; wild-type mice were used for the in vivo study. The magnet configuration that resulted in a higher magnetic targeting efficiency was investigated by evaluating the iron content in homogenated murine liver tissues.

FINDINGS

SLNs, characterized by an average size smaller than 200 nm, retained their superparamagnetic behavior and relevant molecular resonance imaging properties as negative contrast agents. The evaluation of iron accumulation in the liver tissues was consistent with the magnetic induction profile of each magnet configuration, concurring with the results predicted by simulation analysis and obtained by measurements in living mice.

Mechanistic Modelling Identifies and Addresses the Risks of Empiric Concentration-Guided Sorafenib Dosing

The primary objective of this study is to evaluate the capacity of concentration-guided sorafenib dosing protocols to increase the proportion of patients that achieve a sorafenib maximal concentration (C_max) within the range 4.78 to 5.78 μg/mL. A full physiologically based pharmacokinetic model was built and validated using Simcyp^® (version 19.1). The model was used to simulate sorafenib exposure in 1000 Sim-Cancer subjects over 14 days. The capacity of concentration-guided sorafenib dose adjustment, with/without model-informed dose selection (MIDS), to achieve a sorafenib C_max within the range 4.78 to 5.78 μg/mL was evaluated in 500 Sim-Cancer subjects. A multivariable linear regression model incorporating hepatic cytochrome P450 (CYP) 3A4 abundance, albumin concentration, body mass index, body surface area, sex and weight provided robust prediction of steady-state sorafenib C_max (R² = 0.883; p < 0.001). These covariates identified subjects at risk of failing to achieve a sorafenib C_max ≥ 4.78 μg/mL with 95.0% specificity and 95.2% sensitivity. Concentration-guided sorafenib dosing with MIDS achieved a sorafenib C_max within the range 4.78 to 5.78 μg/mL for 38 of 52 patients who failed to achieve a C_max ≥ 4.78 μg/mL with standard dosing. In a simulation setting, concentration-guided dosing with MIDS was the quickest and most effective approach to achieve a sorafenib C_max within a designated range.

Activity of Sorafenib Plus Capecitabine in Previously Treated Metastatic Colorectal Cancer

LESSONS LEARNED

Treatment for patients with metastatic colorectal cancer (mCRC) typically involves multiple lines of therapy with eventual development of treatment resistance. In this single-arm, phase II study involving heavily pretreated patients, the combination of sorafenib and capecitabine yielded a clinically meaningful progression-free survival of 6.2 months with an acceptable toxicity profile. This oral doublet therapy is worthy of continued investigation for clinical use in patients with mCRC.

BACKGROUND

Capecitabine (Cape) is an oral prodrug of the antimetabolite 5-fluorouracil. Sorafenib (Sor) inhibits multiple signaling pathways involved in angiogenesis and tumor proliferation. SorCape has been previously studied in metastatic breast cancer.

METHODS

This single-arm, phase II study was designed to evaluate the activity of SorCape in refractory metastatic colorectal cancer (mCRC). Patients received Sor (200 mg p.o. b.i.d. max daily) and Cape (1,000 mg/m² p.o. b.i.d. on days 1-14) on a 21-day treatment cycle. Primary endpoint was progression-free survival (PFS) with preplanned comparison with historical controls.

RESULTS

Forty-two patients were treated for a median number of 3.5 cycles (range 1-39). Median PFS was 6.2 (95% confidence interval [CI], 4.3-7.9) months, and overall survival (OS) was 8.8 (95% CI, 4.3-12.2) months. One patient (2.4%) had partial response (PR), and 22 patients (52.4%) had stable disease (SD) for a clinical benefit rate of 54.8% (95% CI, 38.7%-70.2%). Hand-foot syndrome was the most common adverse event seen in 36 patients (85.7%) and was grade ≥ 3 in 16 patients (38.1%). One patient (2.4%) had a grade 4 sepsis, and one patient (2.4%) died while on treatment.

CONCLUSION

SorCape in this heavily pretreated population yielded a reasonable PFS with manageable but notable toxicity. The combination should be investigated further.

Estimating Similarity of Dose-Response Relationships in Phase I Clinical Trials-Case Study in Bridging Data Package

Bridging studies are designed to fill the gap between two populations in terms of clinical trial data, such as toxicity, efficacy, comorbidities and doses. According to ICH-E5 guidelines, clinical data can be extrapolated from one region to another if dose–reponse curves are similar between two populations. For instance, in Japan, Phase I clinical trials are often repeated due to this physiological/metabolic paradigm: the maximum tolerated dose (MTD) for Japanese patients is assumed to be lower than that for Caucasian patients, but not necessarily for all molecules. Therefore, proposing a statistical tool evaluating the similarity between two populations dose–response curves is of most interest. The aim of our work is to propose several indicators to evaluate the distance and the similarity of dose–toxicity curves and MTD distributions at the end of some of the Phase I trials, conducted on two populations or regions. For this purpose, we extended and adapted the commensurability criterion, initially proposed by Ollier et al. (2019), in the setting of completed phase I clinical trials. We evaluated their performance using three synthetic sets, built as examples, and six case studies found in the literature. Visualization plots and guidelines on the way to interpret the results are proposed.

Association of Gastric Acid Suppression and Sorafenib Efficacy in Advanced Hepatocellular Carcinoma

BACKGROUND

Recent studies have revealed that coadministration of gastric acid suppressants reduces the efficacy of the tyrosine kinase inhibitors erlotinib and sunitinib in patients with non-small cell lung cancer and renal cell carcinoma, respectively. The authors have therefore assessed if the concurrent use of gastric acid suppressants and sorafenib impairs outcomes in patients with advanced hepatocellular carcinoma (HCC).

METHODS

A retrospective analysis was conducted on all patients treated with sorafenib for advanced HCC at a single tertiary referral unit in the United Kingdom, between January 2008 and January 2014. A multivariate Cox proportional hazard model was used to assess the effect of the concomitant use of gastric acid suppression and sorafenib on progression-free survival (PFS) and overall survival (OS).

RESULTS

Data were collected from 197 patients, of which 182 could be assessed for this study; 77 (42%) were on concurrent gastric acid suppression therapy. After adjusting for imbalances between the groups, a Cox regression analysis gave an adjusted hazard ratio for the concurrent acid suppression group compared with the no acid suppression group of 5.4 (95% confidence interval, 3.6-7.9) for PFS and 1.85 (95% confidence interval, 1.3-2.6) for OS.

CONCLUSIONS

This single-center experience shows that patients with advanced HCC taking sorafenib and concomitant gastric acid suppression therapy have significantly inferior PFS and OS. This is the first time that this negative interaction has been reported and further prospective validation is warranted.

Ras Signaling in Breast Cancer

Ras proteins mediate extracellular and cytoplasmic signaling networks via receptor tyrosine kinase. The Ras pathway induces activation of signaling molecules involved in cell proliferation and growth, cell survival and apoptosis, metabolism, and motility. Although Ras mutations in breast cancer are not frequently reported, hyperactivation of Ras signaling plays an important role in breast cancer growth and progression. Oncogenic Ras activation occurs via loss of Ras GTPase-activating proteins, overexpression of growth factor receptor, and stimulation by various cytokines. Effective control of oncogenic Ras is one of the therapeutic strategies in breast cancer. The mechanisms of intracellular localization, activation, and signaling pathway of Ras in cancer have been used to develop therapeutic candidates. Recent studies have reported an effective therapy for breast cancer by inhibition of enzymes involved in the posttranslational modification of Ras, such as farnesyltransferase and geranylgeranyltransferase 1, and anti-cancer therapies targeting the epidermal growth factor receptor (EGFR). Emerging targets involved in EGF-mediated Ras activity in breast cancer have shed new insight into Ras activation in breast cancer progression. These alternative mechanisms for Ras signaling pathway may suggest novel therapeutic approaches for targeting Ras in breast cancer. In spite of the difficulties in targeting Ras protein, important discoveries highlight the direct inhibition of Ras activity. Further studies may elucidate the effects of targeting Ras protein and the clinical relevance thereof.

Current Treatment Options for HCC: From Pharmacokinetics to Efficacy and Adverse Events in Liver Cirrhosis

BACKGROUND

Hepatocellular carcinoma (HCC) is among the world's most common cancers. For over ten years, the only medical treatment for it has been the multikinase inhibitor Sorafenib. Currently, however, other first or second-line therapeutic options have also shown efficacy against HCC, such as multikinase inhibitors (Regorafenib, Lenvatinib, and Cabozantinib), a monoclonal antibody against the vascular endothelial growth factor receptor 2 (Ramucirumab), and immune-checkpoint inhibitors (Nivolumab, Pembrolizumab, Ipilimumab).

AIM

The aim of this paper is to review the metabolic pathways of drugs that have been tested for the treatment of HCC and the potential influence of liver failure over those pathways.

METHODS

The Food and Drug Administration (FDA)'s and European Medicines Agency (EMA)'s datasheets, results from clinical trials and observational studies have been reviewed.

RESULTS

This review summarizes the current knowledge regarding targets, metabolic pathways, drug interactions, and adverse events of medical treatments for HCC in cirrhotic patients.

CONCLUSION

The new scenario of systemic HCC therapy includes more active drugs with different metabolic pathways and different liver adverse events. Clinical and pharmacological studies providing more data on the safety of these molecules are urgently needed.

Experience of sorafenib treatment in differentiated thyroid cancer from Taiwan

BACKGROUND

Sorafenib has been shown to prolong the progression free survival (PFS) of advanced radioiodine (RAI) refractory differentiated thyroid cancer (DTC) and has been approved by the FDA as the result of the phase III DECISION trial. Sorafenib has been reimbursed for the treatment of RAI refractory DTC in Taiwan since Jan 2017. High percentage of adverse events (AE) was noted in DECISION trial. We conducted a study to show the real-world experience of sorafenib in Taiwan.

METHODS

We retrospectively collected the clinical data, including dose, AE, and PFS of sorafenib, of the DTC patients who received sorafenib treatment in National Cheng Kung University Hospital and China Medical University Hospital by chart review from 2012 to 2018.

RESULTS

Thirty-six advanced DTC patients with progression were included in this study. The starting dose of sorafenib in most patients was 200 mg twice daily and the mean daily maintenance dose was 433 mg. Five patients had partial response (13.9%) and 28 patients had stable disease (77.8%). The median PFS was 17.3 months (95% confidence interval: 11.9-33.6 months). Daily maintenance dose ≥ 600 mg was associated with better PFS (median PFS, not reached). The most common toxicity of sorafenib was hand foot skin reaction (69%), followed by diarrhea (42%), and skin rash (33%). Most of the toxicities were grade I/II.

CONCLUSION

Higher maintenance dose of sorafenib is associated with longer PFS while starting from half dose is feasible to minimize the incidence of high grade toxicities in the real-world use of sorafenib.

Brain accumulation of tivozanib is restricted by ABCB1 (P-glycoprotein) and ABCG2 (breast cancer resistance protein) in mice

Tivozanib is a potent and selective inhibitor of VEGFR1-3, recently approved by the EMA for first-line treatment of renal cell carcinoma. We used wild-type, knockout, and transgenic mouse strains to study the effects of the drug transporters ABCB1, ABCG2, and OATP1A/1B, and of the CYP3A enzymes on the oral availability and tissue distribution of tivozanib. Tivozanib was transported by human ABCB1 and mouse Abcg2 in polarized MDCK-II cells. Upon oral administration, tivozanib showed rapid absorption and the plasma concentration-time curves showed secondary peaks in all mouse strains, suggesting enterohepatic recirculation. The brain-to-plasma ratios were significantly increased in Abcb1a/1b^-/- (2.2-fold) and Abcb1a/1b;Abcg2^-/- (2.6-fold) mice compared to wild-type mice, indicating a modest protective role of these transporters in the blood-brain barrier. Slco1a/1b^-/- mice showed a 1.2-fold lower liver-to-plasma ratio than wild-type mice, suggesting a minor role of mOatp1a/1b in tivozanib liver distribution. Oral plasma pharmacokinetics of tivozanib was not significantly altered in these mouse strains, nor in Cyp3a knockout and CYP3A4-humanized mice. The modest effect of ABC transporters on tivozanib brain accumulation, if also true in humans, might mean that this drug is not strongly limited in its therapeutic efficacy against malignant lesions situated partly or completely behind the blood-brain barrier.

CRISPR/Cas9 genome-wide screening identifies KEAP1 as a sorafenib, lenvatinib, and regorafenib sensitivity gene in hepatocellular carcinoma

Sorafenib is the first-line drug used for patients with advanced hepatocellular carcinoma (HCC). However, acquired sorafenib resistance in cancer patients limits its efficacy. Here, we performed the first genome-wide CRISPR/Cas9-based screening on sorafenib-treated HCC cells to identify essential genes for non-mutational mechanisms related to acquired sorafenib resistance and/or sensitivity in HCC cells. KEAP1 was identified as the top candidate gene by Model-based Analysis of Genome-wide CRISPR/Cas9 Knockout (MAGeCK). KEAP1 disrupted HCC cells were less sensitive than wild-type cells in short- and long-term sorafenib treatments. Compared to wild-type cells, KEAP1-disrupted cells showed lower basal and sorafenib-induced reactive oxygen species (ROS) levels and were more resistant to oxidative stress-induced cell death. The absence of KEAP1 led to increased activity of Nrf2, a key transcription factor controlling antioxidant responses, as further evidenced by increased expression of Nrf2-controlled genes including NQO1, GPX2 and TXNRD1, which were positively associated with chemoresistance. In addition, KEAP1 disruption counteracted the reduction of cell viability and the elevation of ROS caused by lenvatinib, a drug that recently showed clinical efficacy as a first-line treatment for unresectable HCC. Finally, Keap1 disruption also increased the resistance of cells to regorafenib, a recently approved drug to treat HCC as a second line therapy. Taken together, our data indicate that deregulation of the KEAP1/Nrf2 pathway following KEAP1 inactivation contributes to sorafenib, lenvatinib, and regorafenib resistance in human HCC cells through up-regulation of Nrf2 downstream genes and decreased ROS levels.

Kinase Inhibitors and Ovarian Cancer

Ovarian cancer is fifth in the rankings of cancer deaths among women, and accounts for more deaths than any other gynecological malignancy. Despite some improvement in overall-(OS) and progression-free survival (PFS) following surgery and first-line chemotherapy, there is a need for development of novel and more effective therapeutic strategies. In this mini review, we provide a summary of the current landscape of the clinical use of tyrosine kinase inhibitors (TKIs) and mechanistic target of rapamycin (mTOR) inhibitors in ovarian cancer. Emerging data from phase I and II trials reveals that a combinatorial treatment that includes TKIs and chemotherapy agents seems promising in terms of PFS despite some adverse effects recorded; whereas the use of mTOR inhibitors seems less effective. There is a need for further research into the inhibition of multiple signaling pathways in ovarian cancer and progression to phase III trials for drugs that seem most promising.

Sorafenib

Sorafenib (BAY-43-9006), marketed by Bayer as Nexavar® (USA), is anticancer drug approved by US-FDA for the treatment of unresectable hepatocellular carcinoma and advanced renal cell carcinoma. Sorafenib inhibited tumor growth and angiogenesis through targeting both the RAF/MEK/ERK pathway and receptor tyrosine kinases. This study presents a comprehensive profile of sorafenib, including detailed nomenclature, formula, elemental analysis, methods of preparation, physico-chemical characteristics, and methods of analysis (including spectroscopic, electrochemical, and chromatographic methods of analysis). Spectroscopic and spectrometric analyses include UV/vis spectroscopy, vibrational spectroscopy, nuclear magnetic resonance spectrometry ((1)H and (13)C NMR), and mass spectrometry. Chromatographic methods of analyses include thin layer chromatography and high-performance liquid chromatography. Only few stability indicating methods were found for quantification of sorafenib after exposing tablet dosage form to various stress conditions such as hydrolysis, oxidation, thermal stress, photo and UV light. However, none of these described methods were made to separate and quantify the degradation products. Pharmacology studies including pharmacodynamics, mechanism of action, pharmacokinetics and drug-drug interactions were also presented. An appropriate table and figures were attached to each of the above mentioned sections along with total of 55 references.

Sorafenib: key lessons from over 10 years of experience

Introduction: In 2005, sorafenib was the first targeted therapy approved for advanced renal cell carcinoma (RCC), transforming treatment. In hepatocellular carcinoma (HCC), for more than a decade, sorafenib remained the only approved systemic therapy to have demonstrated a survival benefit in first-line unresectable HCC. In 2013, sorafenib was the first targeted agent approved for patients with differentiated thyroid cancer (DTC) refractory to radioactive iodine treatment. Areas covered: This review discusses the development, advances, and challenges associated with sorafenib use in RCC, HCC, and DTC over the past decade. A search was performed on PubMed and key congresses as required, with no time limits. Expert commentary: Sorafenib has had a lasting impact on the therapeutic landscape of RCC, HCC, and DTC, and remains an important treatment option despite a rapidly evolving treatment landscape. Extensive clinical and real-world experience has been invaluable in improving patient management and maximizing benefit from treatment. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in HCC and DTC. We have no doubt that sorafenib will continue to be an important treatment option in the coming years.

Use of human induced pluripotent stem cell-derived cardiomyocytes to assess drug cardiotoxicity

Cardiotoxicity has historically been a major cause of drug removal from the pharmaceutical market. Several chemotherapeutic compounds have been noted for their propensities to induce dangerous cardiac-specific side effects such as arrhythmias or cardiomyocyte apoptosis. However, improved preclinical screening methodologies have enabled cardiotoxic compounds to be identified earlier in the drug development pipeline. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can be used to screen for drug-induced alterations in cardiac cellular contractility, electrophysiology, and viability. We previously established a novel 'cardiac safety index' (CSI) as a metric that can evaluate potential cardiotoxic drugs via high-throughput screening of hiPSC-CMs. This metric quantitatively examines drug-induced alterations in CM function, using several in vitro readouts, and normalizes the resulting toxicity values to the in vivo maximum drug blood plasma concentration seen in preclinical or clinical pharmacokinetic models. In this ~1-month-long protocol, we describe how to differentiate hiPSCs into hiPSC-CMs and subsequently implement contractility and cytotoxicity assays that can evaluate drug-induced cardiotoxicity in hiPSC-CMs. We also describe how to carry out the calculations needed to generate the CSI metric from these quantitative toxicity measurements.

Systemic therapy for intermediate and advanced hepatocellular carcinoma: Sorafenib and beyond

The hepatocellular carcinoma (HCC) treatment landscape changed a decade ago, with sorafenib demonstrating survival benefit in the first-line setting and becoming the first systemic therapy to be approved for HCC. More recently, regorafenib and nivolumab have received approval in the second-line setting after sorafenib, with further positive phase 3 studies emerging in the first line (lenvatinib non-inferior to sorafenib) and second line versus placebo (cabozantinib and ramucirumab). A key recommendation in the management of patients receiving sorafenib is to promote close communication between the patient and the physician so that adverse events (AEs) are detected early and severe AEs can be prevented. Sorafenib-related AEs have been identified as clinical biomarkers for sorafenib efficacy. Healthcare professionals have become more efficient in managing AEs, identifying patients who are likely to benefit from treatment, and assessing response to treatment, resulting in a trend towards increased overall survival in the sorafenib arms of clinical studies. The rapidly changing treatment landscape due to the emergence of new treatment options (sorafenib and lenvatinib equally effective in first line; regorafenib, cabozantinib, and ramucirumab showing OS benefit in second line with nivolumab approved by the FDA based on response rate) underscores the importance of re-assessing the role of the first approved systemic agent in HCC, sorafenib.

Pharmacodynamic and Pharmacokinetic Markers For Anti-angiogenic Cancer Therapy: Implications for Dosing and Selection of Patients

Angiogenesis is integral to tumour growth and invasion, and is a key target for cancer therapeutics. However, for many of the licensed indications, only a modest clinical benefit has been observed for both monoclonal antibody and small-molecule tyrosine kinase inhibitor anti-angiogenic therapy. Pre-clinical and clinical studies have attempted to evaluate circulating, imaging, genomic, pharmacokinetic, and pharmacodynamic markers that may aid both the selection of patients for treatment and define dosing. Correct dosing is likely to be critical in the context of vascular normalization to allow better delivery of concomitant anti-cancer therapy and novel imaging techniques hold much promise in the early evaluation of pharmacodynamic response to improve efficacy.

In-vivo relation between plasma concentration of sorafenib and its safety in Chinese patients with metastatic renal cell carcinoma: a single-center clinical study

This single-center, observational study analyzed the association between plasma concentration of sorafenib and its safety and efficacy in Chinese patients with metastatic renal cell carcinoma (mRCC). Adult patients with RCC (n = 94), treated with sorafenib were enrolled between January 2014 and January 2015. Sorafenib plasma concentrations were measured by liquid chromatography-tandem mass spectrometry. Safety and efficacy variables were evaluated using National Cancer Institute-Common Toxicity Criteria for Adverse Events and Response Evaluation Criteria in Solid Tumors criteria. Association of plasma concentration with safety and efficacy was analyzed. The steady state plasma concentration of sorafenib after 2 weeks of treatment ranged from 881 to 12,526 ng/mL. Major adverse reactions (ADRs) included diarrhea (76.5%), hand-foot syndrome (HFS; 68.99%) and fatigue (55.32%). Significant association was reported between plasma concentration and all the ADRs except rash. At 6 weeks, complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) was reported in 3.1%, 13.82%, 52.2% and 13.82% patients, respectively. Objective response and disease control rates were 17.02% and 69.14%. Plasma concentration of sorafenib was >10,000 ng/mL in patients with severe ADRs, which decreased with reduction in dose or discontinuation of treatment. After 21.2 weeks follow-up, median progression free survival was 12.3 months. CR, PR, SD and PD were reported in 1%, 46%, 33% and 19% patients. In conclusion, plasma concentration of sorafenib was associated with its safety and efficacy in Chinese patients with mRCC.

Use of Sorafenib in Two Metastatic Renal Cell Cancer Patients with End-Stage Renal Impairment Undergoing Replacement Hemodialysis

Patients with renal cell carcinoma (RCC) may exhibit renal impairment as a more or less direct consequence of their primary disease. Renal impairment may become a severe complication and alter the normal pharmacokinetic and pharmacodynamic behavior of treatment drugs, thus increasing the risk of side effects. We will discuss the cases of two advanced RCC patients with end-stage renal impairment submitted to dialysis who were treated with sorafenib tosylate in our center.

Our experience confirms the scarce literature data available so far that indicate that sorafenib can be used in patients undergoing dialysis. Dialysis cannot be considered per se a contraindication to sorafenib therapy, which can be effective. However, patients must be carefully selected and monitored, since sorafenib administration unquestionably increases the risk of side effects in patients affected by several conditions.

A whole-animal platform to advance a clinical kinase inhibitor into new disease space

Synthetic tailoring of approved drugs for new indications is often difficult, as the most appropriate targets may not be readily apparent, and therefore few roadmaps exist to guide chemistry. Here, we report a multidisciplinary approach for accessing novel target and chemical space starting from an FDA-approved kinase inhibitor. By combining chemical and genetic modifier screening with computational modeling, we identify distinct kinases that strongly enhance ('pro-targets') or limit ('anti-targets') whole-animal activity of the clinical kinase inhibitor sorafenib in a Drosophila medullary thyroid carcinoma (MTC) model. We demonstrate that RAF-the original intended sorafenib target-and MKNK kinases function as pharmacological liabilities because of inhibitor-induced transactivation and negative feedback, respectively. Through progressive synthetic refinement, we report a new class of 'tumor calibrated inhibitors' with unique polypharmacology and strongly improved therapeutic index in fly and human MTC xenograft models. This platform provides a rational approach to creating new high-efficacy and low-toxicity drugs.

Prediction of Apparent Oral Clearance of Small-Molecule Inhibitors in Pediatric Patients

The purpose of this study was to build regression models for the prediction of apparent oral clearance (CL/F) for small-molecule inhibitors in the pediatric population using data obtained from adults. Two approaches were taken; a simple allometric regression model which considers no interdrug or interindividual variability and an allometric regression model with mixed-effects modeling where some variability parameters are included in the model. Average CL/F values were obtained for 15 drugs at various dosages from 31 literatures (a total of 139 data sets) conducted in adults and for 15 drugs from 26 literatures (62 data sets) conducted in children. Data were randomly separated into the "modeling" or "validation" data set, and the 2 allometric regression models were applied to the modeling data set. The predictive ability of the models was examined by comparing the observed and model-predicted CL/F in children using the validation data set. The percentage root mean square error was 17.2% and 26.3% in the simple allometric regression model and the allometric regression model with mixed-effects modeling, respectively. The predictive ability of the 2 models seems acceptable, suggesting that they could be useful for predicting the CL/F of new small-molecule inhibitors and for determining adequate doses in clinical pharmacotherapy for children.

Impact of surgical treatment after sorafenib therapy for advanced hepatocellular carcinoma

BACKGROUND

For advanced hepatocellular carcinoma (HCC), surgical treatment after sorafenib induction has rarely been reported. We examined the survival benefit of additional surgical treatment in sorafenib-treated patients.

METHODS

Thirty-two advanced HCC patients were given sorafenib from July 2009 to July 2012, and we statistically analyzed the relevant predictive factors of the long-term survival. The institutional review board of Kumamoto University Hospital approved this study (Approval number 1038).

RESULTS

The median duration of sorafenib administration was 56.5 days (range 5-945). The cumulative overall survival rate was 44.6, 33.4, 26.0 and 17.8% at 1, 2, 3 and 5 years, respectively. The median survival time was 11.2 months. A survival of more than 3 years after the initiation of sorafenib induction was observed in seven patients, five of whom were subjected to additional surgical intervention. Additional surgery was the most significant factor predicting a survival exceeding 3 years (P < 0.0001) and represents an independent prognostic factor [hazard ratio (HR) 0.07; P = 0.01], followed by the total dose of sorafenib. The surgical interventions comprised two hepatic resections ± radiofrequency ablation, two radiofrequency ablations and one lung resection.

CONCLUSIONS

A long-term survival might be obtained for select HCC patients given adequate additional surgical treatment, even after sorafenib induction.

Sorafenib for the treatment of breast cancer

INTRODUCTION

Breast cancer treatment includes many options depending on the tumor clinicopathological profile, which groups breast cancer into various subtypes. Bevacizumab is currently the only drug capable of targeting angiogenesis in breast cancer. Sorafenib has also been studied in combination with other agents. Areas covered: Pharmacological aspects of sorafenib, including results from preclinical studies on breast cancer cells; findings about clinical efficacy and safety in both single-arm and randomized clinical trials; ongoing trials. Expert opinion: Since sorafenib as a single agent has shown limited efficacy in breast cancer, its combination with other drugs is under investigation. Dose reduction is the main challenge when sorafenib is combined with chemotherapy or endocrine therapy. Although randomized phase-II trials on sorafenib plus chemotherapy versus chemotherapy alone have shown potential benefits in progression-free survival, preliminary results from a phase-III study in combination with capecitabine are negative. The definitive results of this trial and results from other ongoing phase-II trials will determine further developments of sorafenib in breast cancer. Although these additional data could help determine the most appropriate dose, drug combination and patient settings, a confirmation of the preliminary negative results reported in the phase-III trial are likely to discourage further use of sorafenib in breast cancer, given its non-negligible toxicity, lack of predicting markers, and the number of more promising drugs for breast cancer.

Inefficiencies and Patient Burdens in the Development of the Targeted Cancer Drug Sorafenib: A Systematic Review

Failure in cancer drug development exacts heavy burdens on patients and research systems. To investigate inefficiencies and burdens in targeted drug development in cancer, we conducted a systematic review of all prelicensure trials for the anticancer drug, sorafenib (Bayer/Onyx Pharmaceuticals). We searched Embase and MEDLINE databases on October 14, 2014, for prelicensure clinical trials testing sorafenib against cancers. We measured risk by serious adverse event rates, benefit by objective response rates and survival, and trial success by prespecified primary endpoint attainment with acceptable toxicity. The first two clinically useful applications of sorafenib were discovered in the first 2 efficacy trials, after five drug-related deaths (4.6% of 108 total) and 93 total patient-years of involvement (2.4% of 3,928 total). Thereafter, sorafenib was tested in 26 indications and 67 drug combinations, leading to one additional licensure. Drug developers tested 5 indications in over 5 trials each, comprising 56 drug-related deaths (51.8% of 108 total) and 1,155 patient-years (29.4% of 3,928 total) of burden in unsuccessful attempts to discover utility against these malignancies. Overall, 32 Phase II trials (26% of Phase II activity) were duplicative, lacked appropriate follow-up, or were uninformative because of accrual failure, constituting 1,773 patients (15.6% of 11,355 total) participating in prelicensure sorafenib trials. The clinical utility of sorafenib was established early in development, with low burden on patients and resources. However, these early successes were followed by rapid and exhaustive testing against various malignancies and combination regimens, leading to excess patient burden. Our evaluation of sorafenib development suggests many opportunities for reducing costs and unnecessary patient burden in cancer drug development.

Pharmacokinetic Aspects of Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitors

Scientists have identified the impact of angiogenesis on tumor growth and survival. Among other efficient drugs, several small-molecule tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor receptor (VEGFR) have been developed and have already been integrated into the treatment of various advanced malignancies. This review provides a compilation of current knowledge on the pharmacokinetic aspects of all VEGFR-TKIs already approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) and of those still under investigation. Additional information on substance metabolism, potential for drug-drug interactions (DDIs), and the need for dose adaptation in patients with predominant renal and/or hepatic impairment has been included. All TKIs introduced in this review were administered orally, allowing for easy drug handling for healthcare professionals and patients. For almost all substances, the maximum plasma concentrations were reached within a short period of time. The majority of the substances showed a high plasma protein binding and their excretion occurred via the feces and, to a lesser extent, via the urine. In most cases, dose adaptation in patients with mild to moderate renal or hepatic impairment is not recommended. Cytochrome P450 (CYP) 3A4 was found to play a crucial role in the drug metabolic processes of many compounds. In order to prevent unwanted DDIs, co-administration of VEGFR TKIs together with CYP3A4 inhibitors or inducers should be avoided. Throughout all TKIs, the data indicate high inter-individual variability. The causes of this are still unclear and require further research to allow for individualization of treatment regimens.

Feasibility, efficacy and safety of tyrosine kinase inhibitor treatment in hemodialyzed patients with renal cell cancer: 10 years of experience

AIMS

Sine efficiency of tyrosine kinase inhibitor (TKI) therapy in dialyzed patients is still unclear we aim to analyze the outcome of treatment in such cohort.

PATIENTS & METHODS

We analyzed treatment outcomes of patients with clear cell renal cell carcinoma (ccRCC) with special focus on those who were also treated with hemodialysis and described treatment safety and progression-free survival of eight patients treated with TKIs and hemodialysis.

DISCUSSION & CONCLUSION

Our report supports statement that TKI treatment of dialyzed patients is safe and effective. ccRCC increases risk of developing renal insufficiency as well as end-stage renal disease that require dialysis. Introduction of multitargeted receptor kinase inhibitors (TKIs), including sunitinib, sorafenib and pazopanib significantly expanded life time expectancy of metastatic renal clear cell carcinoma. The advance also applies to patients with ccRCC and end-stage renal disease who undergo dialyses.

Sorafenib: 10 years after the first pivotal trial

Sorafenib is an oral multikinase inhibitor with anticancer activity against a wide spectrum of cancers. It is currently approved for the treatment of patients with hepatocellular carcinoma, advanced renal cell carcinoma or progressive, locally advanced or metastatic differentiated thyroid carcinoma. In this review, we present a number of studies that investigated the efficacy and safety of sorafenib in these settings. We also discuss the perspectives on the use of this molecule, including the role of sorafenib as comparator for the development of new drugs, the combination of sorafenib with additional therapies (such as transarterial chemoembolization for hepatocellular carcinoma) and the use of this treatment in several other advanced refractory solid tumors.

Effect of food and acid-reducing agents on the absorption of oral targeted therapies in solid tumors

Oral targeted therapies represent an increasingly important group of drugs within modern oncology. With the shift from intravenously to orally administered drugs, drug absorption is a newly introduced factor in drug disposition. The process of absorption can have a large effect on inter- and intrasubject variability in drug exposure and thereby potentially treatment benefit or the severity of toxicities. The intake of oral targeted therapies with food and concomitant use of acid-reducing agents (ARAs) can significantly affect drug absorption. The size and direction of the effect of food and ARAs on drug absorption varies among drugs as a result of different chemical characteristics. Therefore, an awareness and understanding of these effects for each drug is essential to optimize patient outcomes.

New Insight into the Anti-liver Fibrosis Effect of Multitargeted Tyrosine Kinase Inhibitors: From Molecular Target to Clinical Trials

Tyrosine kinases (TKs) is a family of tyrosine protein kinases with important functions in the regulation of a broad variety of physiological cell processes. Overactivity of TK disturbs cellular homeostasis and has been linked to the development of certain diseases, including various fibrotic diseases. In regard to liver fibrosis, several TKs, such as vascular endothelial growth factor receptor, platelet-derived growth factor receptor, fibroblast growth factor receptor, and epidermal growth factor receptor kinases, have been identified as central mediators in collagen production and potential targets for anti-liver fibrosis therapies. Given the essential role of TKs during liver fibrogenesis, multitargeted inhibitors of aberrant TK activity, including sorafenib, erlotinib, imatinib, sunitinib, nilotinib, brivanib and vatalanib, have been shown to have potential for treating liver fibrosis. Beneficial effects are observed by researchers of this field using these multitargeted TK inhibitors in preclinical animal models and in patients with liver fibrosis. The present review will briefly summarize the anti-liver fibrosis effects of multitargeted TK inhibitors and molecular mechanisms.

Inflammatory Signaling by NOD-RIPK2 Is Inhibited by Clinically Relevant Type II Kinase Inhibitors

RIPK2 mediates pro-inflammatory signaling from the bacterial sensors NOD1 and NOD2, and is an emerging therapeutic target in autoimmune and inflammatory diseases. We observed that cellular RIPK2 can be potently inhibited by type II inhibitors that displace the kinase activation segment, whereas ATP-competitive type I inhibition was only poorly effective. The most potent RIPK2 inhibitors were the US Food and Drug Administration-approved drugs ponatinib and regorafenib. Their mechanism of action was independent of NOD2 interaction and involved loss of downstream kinase activation as evidenced by lack of RIPK2 autophosphorylation. Notably, these molecules also blocked RIPK2 ubiquitination and, consequently, inflammatory nuclear factor κB signaling. In monocytes, the inhibitors selectively blocked NOD-dependent tumor necrosis factor production without affecting lipopolysaccharide-dependent pathways. We also determined the first crystal structure of RIPK2 bound to ponatinib, and identified an allosteric site for inhibitor development. These results highlight the potential for type II inhibitors to treat indications of RIPK2 activation as well as inflammation-associated cancers.

A multicenter, phase II study of the RAF-kinase inhibitor sorafenib in patients with advanced renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has advanced significantly over the last two decades. This multicenter study was designed with the primary objective to evaluate the efficacy and safety of sorafenib as first-line treatment in patients with advanced or metastatic RCC in the Middle East, who were considered to be ineligible for other approved first-line therapies. A total of 75 eligible patients from 8 centers in the Middle East were included in this study. The patients comprised 48 men and 27 women, with a median age of 52 years (range, 19-78 years). A total of 50 patients had clear cell carcinoma, 17 had papillary carcinoma and 8 had other pathological subtypes. At enrollment, 55 of the 75 patients had undergone previous nephrectomy. A total of 67 patients presented with metastatic disease, while 8 patients had regional residual lesions or local recurrence. The patients were treated with 400 mg oral sorafenib twice daily on a continuous basis as a single agent. Treatment was discontinued upon disease progression, prohibitive toxicity, surgical complications, loss to follow-up, or refusal to continue therapy. The median treatment duration was 21 weeks (range, 1-137 weeks). Sorafenib was tolerated by the majority of the patients. Grade 3/4 hand-foot syndrome occurred in 17 patients; diarrhea, elevated liver enzymes and fatigue were observed in 3 patients each; and grade 3/4 vomiting, hypertension and anemia, in 1 patient each. Of the 75 patients included in this study, 60 were evaluable for response. One patient achieved a complete response for 91 weeks and 6 patients exhibited a partial response (median duration of 23 weeks) with an overall response rate of 11.7%. Disease stabilization occurred in 37 patients (61.7%). Thus, disease control was achieved in 44 of the 60 patientrs (73%). At a median follow-up period of 53.5 weeks (range, 8.5-192 weeks), an intention-to-treat analysis demonstrated a median time-to-disease progression of 25.7 weeks, with a median overall survival of 54.8 weeks. In conclusion, sorafenib was found to be tolerable and effective as first-line therapy in patients with advanced RCC.

Efficacy and safety of sorafenib for treatment of Japanese metastatic renal cell carcinoma patients undergoing hemodialysis

BACKGROUND

Little information has been published on the use of tyrosine kinase inhibitors for treatment of patients undergoing hemodialysis (HD). We investigated the efficacy and safety of sorafenib for metastatic renal cell carcinoma (mRCC) patients undergoing HD.

METHODS

Twenty patients undergoing HD were treated with sorafenib as first-line therapy for mRCC at our hospital between April 2008 and August 2014. Patient medical records were retrospectively reviewed to evaluate the response to sorafenib and treatment-related toxicity.

RESULTS

Fifteen and 5 patients were classified in the intermediate and poor risk groups, respectively, of the Memorial Sloan-Kettering Cancer Center risk model. Eighteen patients had 3 or more metastatic lesions, and 7 patients had metastases in 2 or more organs. Of 16 patients who had previously undergone nephrectomy, 8 were pathologically diagnosed with non-clear-cell carcinoma. The median duration of sorafenib therapy was 4.7 months. Sorafenib was discontinued owing to progressing disease for 15 patients and because of serious adverse events (AE) (≥grade 3) for 4 patients, i.e. subarachnoid hemorrhage, cerebral hemorrhage, sepsis, and syncope for 1 patient each. Median time to progression was 6.3 months, and median overall survival was 14.2 months.

CONCLUSIONS

In this study, many patients had unfavorable clinical features, for example poor risk classification and metastases in multiple organs. Although sorafenib treatment of HD patients seems feasible, careful monitoring is needed because of the tendency for a high incidence of serious AE, even when a reduced dose is administered.

Dual-drug delivery by porous silicon nanoparticles for improved cellular uptake, sustained release, and combination therapy

Dual-drug delivery of antiangiogenic and chemotherapeutic drugs can enhance the therapeutic effect for cancer therapy. Conjugation of methotrexate (MTX) to porous silicon (PSi) nanoparticles (MTX-PSi) with positively charged surface can improve the cellular uptake of MTX and inhibit the proliferation of cancer cells. Herein, MTX-PSi conjugates sustained the release of MTX up to 96 h, and the released fragments including MTX were confirmed by mass spectrometry. The intracellular distribution of the MTX-PSi nanoparticles was confirmed by transmission electron microscopy. Compared to pure MTX, the MTX-PSi achieved similar inhibition of cell proliferation in folate receptor (FR) over-expressing U87 MG cancer cells, and a higher effect in low FR-expressing EA.hy926 cells. Nuclear fragmentation analysis demonstrated programmed cell apoptosis of MTX-PSi in the high/low FR-expressing cancer cells, whereas PSi alone at the same dose had a minor effect on cell apoptosis. Finally, the porous structure of MTX-PSi enabled a successful concomitant loading of another anti-angiogenic hydrophobic drug, sorafenib, and considerably enhanced the dissolution rate of sorafenib. Overall, the MTX-PSi nanoparticles can be used as a platform for combination chemotherapy by simultaneously enhancing the dissolution rate of a hydrophobic drug and sustaining the release of a conjugated chemotherapeutic drug.

The discovery and development of sorafenib for the treatment of thyroid cancer

INTRODUCTION

Although the prognosis for most differentiated thyroid cancers (DTCs) remains excellent, recurrence and insensitivity to radioactive iodine (RAI) lead to therapeutic challenges and poorer outcomes. In defining the pathogenesis of DTC, multiple genetic alterations have been identified in key pathways focused around receptor tyrosine kinases (RTKs) and the MAPK cascade. Sorafenib was specifically developed to target rapidly accelerated fibrosarcoma (RAF) kinase in the MAPK pathway. It has been shown, however, to have potent inhibition of several key RTKs, RAF kinase and the V600E BRAF mutation, gaining FDA approval in November 2013 for advanced RAI-refractory DTC.

AREAS COVERED

The authors provide a review of the targeted RAF kinase discovery strategy as well as the preclinical and clinical development of sorafenib, leading to FDA approval of DTC. The authors also provide some insight into the clinical use of sorafenib and look at important considerations for treatment.

EXPERT OPINION

Sorafenib significantly improves progression-free survival in metastatic DTC patients who are RAI-refractory. However, the overall survival benefit is still unproven and requires additional follow up. Despite its cost and significant side-effect profile, which results in dose reductions in the majority of DTC patients, sorafenib should be considered for the treatment of RAI-refractory advanced DTC patients following evaluation of their individual risk-benefit stratification.