Multitargeted Receptor Tyrosine Kinase Inhibitor Research Articles

A phase I/Ib study of lenvatinib and cetuximab in patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

6541 Background: Despite overexpression of EGFR in HNSCC, cetuximab monotherapy has limited benefit. Fibroblast growth factor receptor (FGFR) signaling is a known resistance mechanism to EGFR inhibition. Lenvatinib is a multi-targeted receptor tyrosine kinase inhibitor (RTKI) and has unique activity against FGFR 1,2,3, and 4. We are evaluating inhibition of EGFR and RTKs including FGFR through the combination of cetuximab and lenvatinib in patients (pts) with R/M HNSCC. Methods: In this phase I/Ib, single-institution study, pts with measurable disease per RECIST v1.1 that is incurable with surgery and radiation are eligible regardless of prior cetuximab therapy. The dose de-escalation phase included pts with HNSCC and cutaneous squamous cell carcinoma (cSCC) treated with standard cetuximab dosing and lenvatinib in 3 potential dose levels (DL): (0) 24mg, (-1) 20mg, (-2) 14mg oral daily in a standard 3+3 design. The primary objective was to determine the MTD of lenvatinib in combination with cetuximab. The expansion phase included an additional 5 pts with HNSCC treated at the MTD. Exploratory endpoints include ORR and PFS in HNSCC pts treated at the MTD. Results: 12 evaluable pts were treated on the dose de-escalation phase. There were no DLTs on DL 0; however, 3/6 pts were removed immediately following the 28-day DLT period due to toxicity that included extensive thrombotic events and athlerosclerotic disease. On DL -1, 0/6 pts (5 HNSCC/1 cSCC) had a DLT establishing lenvatinib 20mg daily as the MTD. 7 pts were enrolled onto the expansion phase; 4 are currently evaluable for response and 2 are unevaluable because of withdrawal due to a cetuximab reaction and required surgery. Of the 9 evaluable HNSCC pts treated with lenvatinib 20mg daily, 6 pts had a PR with a 67% ORR. For the 8 pts who have completed treatment, the median PFS is 3.6 months (range 1.6-10.4). Grade 3 AEs regardless of attribution included hypertension (3), oral mucositis (3) and oral cavity fistula (1). The most common AEs were acneiform rash (7), fatigue (6), and hypertension/hypothyroidism/oral mucositis (5 each). Conclusions: The MTD of lenvatinib 20mg daily with cetuximab appears to be active in R/M HSNCC with an impressive preliminary ORR, warranting further evaluation of the efficacy of this combination. Clinical trial information: NCT03524326 .

Potential new therapy of Rapalink-1, a new generation mammalian target of rapamycin inhibitor, against sunitinib-resistant renal cell carcinoma.

Sunitinib, a multitargeted receptor tyrosine kinase inhibitor including vascular endothelial growth factor, has been widely used as a first‐line treatment against metastatic renal cell carcinoma (mRCC). However, mRCC often acquires resistance to sunitinib, rendering it difficult to treat with this agent. Recently, Rapalink‐1, a drug that links rapamycin and the mTOR kinase inhibitor MLN0128, has been developed with excellent therapeutic effects against breast cancer cells carrying mTOR resistance mutations. The aim of the present study was to evaluate the in vitro and in vivo therapeutic efficacy of Rapalink‐1 against renal cell carcinoma (RCC) compared to temsirolimus, which is commonly used as a small molecule inhibitor of mTOR and is a derivative of rapamycin. In comparison with temsirolimus, Rapalink‐1 showed significantly greater effects against proliferation, migration, invasion and cFolony formation in sunitinib‐naïve RCC cells. Inhibition was achieved through suppression of the phosphorylation of substrates in the mTOR signal pathway, such as p70S6K, eukaryotic translation initiation factor 4E‐binding protein 1 (4EBP1) and AKT. In addition, Rapalink‐1 had greater tumor suppressive effects than temsirolimus against the sunitinib‐resistant 786‐o cell line (SU‐R 786‐o), which we had previously established, as well as 3 additional SU‐R cell lines established here. RNA sequencing showed that Rapalink‐1 suppressed not only the mTOR signaling pathway but also a part of the MAPK signaling pathway, the ErbB signaling pathway and ABC transporters that were associated with resistance to several drugs. Our study suggests the possibility of a new treatment option for patients with RCC that is either sunitinib‐sensitive or sunitinib‐resistant.

A phase I study investigation of metabolism, and disposition of [14C]-anlotinib after an oral administration in patients with advanced refractory solid tumors

PurposeAnlotinib is a novel oral multi-targeted receptor tyrosine kinase inhibitor, which selectively inhibits VEGFR2/3, FGFR1-4, PDGFR α/β, c-kit, and Ret. It shows antitumor effect in patients with advanced refractory solid tumors. The detailed absorption, metabolism, and excretion pathways of anlotinib have not yet been fully investigated.MethodsSix male patients were enrolled and divided into two groups. Group A (containing two patients) received 14.15 mg/80 µCi/subject [14C]-anlotinib hydrochloride. Group B (containing four patients) received 14.15 mg/120 µCi/subject [14C]-anlotinib hydrochloride. The blood, urine, and feces of all the six patients after orally administration of [14C]-anlotinib were collected. The absorption, metabolism, and excretion of [14C]-anlotinib were investigated, and the efficacy and safety of anlotinib were evaluated.ResultsIn plasma, the average time to peak concentration (Tmax) of total radioactivity was 4.42 h and the average peak concentration (Cmax) of total radioactivity was 18.80 ng Eq./g. The average values of AUC0-last, AUC0-∞, and MRT0-t were 4071 h.ng Eq./g, 13,555 h.ng Eq./g, and 125 h, respectively. The average recovery of total radioactivity (TRA) in urine and feces was 62.03%, accounting for 48.52% and 13.51% in feces and urine of the total dosage, respectively. The parent drug, a carboxylic metabolite (M30), and mono-oxidation products (M46/M66) were major drug-related components in human plasma. Oxidative metabolism played the major role in drug clearance in human. The major metabolic pathways include oxidative deamination to M2, mono-oxidation to M1, and the formation of M30. Adverse events occurred in five patients and severe adverse events (SAE) occurred in one. Tumor response were evaluated as stable disease (SD) in three, partial response (PR) in one, and progressive disease (PD) in one of the patients, respectively.ConclusionsAnlotinib had a good pharmacokinetic profile with rapid absorption, long half-life, and extensive hepatic metabolism. The adverse events and efficacy were as expected.

Efficacy and safety of anlotinib, a multikinase angiogenesis inhibitor, in combination with epirubicin in preclinical models of soft tissue sarcoma.

BackgroundAnlotinib is a novel, orally administered, multitarget receptor tyrosine kinase inhibitor. It functions by inhibiting tumor angiogenesis and proliferative signaling pathways. In this study, we aimed to investigate the efficacy and safety of anlotinib plus epirubicin in a sarcoma patient‐derived xenografts (PDX) model.MethodsWe firstly established a PDX model using fresh tumor tissues that were surgically removed from a patient diagnosed with malignant fibrous histiocytoma. Thirty‐six PDX models were divided into six groups and treated with anlotinib alone (low‐dose, 1.5 or high‐dose, 3.0 mg/kg/day, oral gavage), or with anlotinib plus epirubicin (3.0 mg/kg/once weekly, i.p.) when the tumors grew to 150‐200 mm3. After 5 weeks of treatment, the mice were sacrificed, and the tumors were measured by weight and processed for IHC and H&E staining. IHC staining was performed to detect CD31, EGFR, MVD, and Ki‐67 on paraffin sections. H&E stainings were performed to examine the microcosmic changes that occurred in the tumor tissues and myocardium, respectively.ResultsAfter 5 weeks, treatment with anlotinib or epirubicin alone significantly inhibited tumor growth in the sarcoma PDX model compared with the vehicle control. Tumor volume in the high‐dose anlotinib group was significantly smaller than the low‐dose anlotinib group (P < .001). Combined high‐dose anlotinib and epirubicin treatment resulted in the most pronounced tumor inhibition. In the groups treated with the anlotinib‐containing regimen, the expression levels of CD31, EGFR, MVD, and Ki‐67 were significantly low. The weight in each group had no statistical differences; the same applied to the hepatic function, cardiac function, and toxicity.ConclusionsHigh‐dose anlotinib combined with epirubicin was an effective and safe therapy for STS.

Sitravatinib Sensitizes ABCB1- and ABCG2-Overexpressing Multidrug-Resistant Cancer Cells to Chemotherapeutic Drugs.

The development of multidrug resistance (MDR) in cancer patients driven by the overexpression of ATP-binding cassette (ABC) transporter ABCB1 or ABCG2 in cancer cells presents one of the most daunting therapeutic complications for clinical scientists to resolve. Despite many novel therapeutic strategies that have been tested over the years, there is still no approved treatment for multidrug-resistant cancers to date. We have recently adopted a drug repurposing approach to identify therapeutic agents that are clinically active and at the same time, capable of reversing multidrug resistance mediated by ABCB1 and ABCG2. In the present study, we investigated the effect of sitravatinib, a novel multitargeted receptor tyrosine kinase inhibitor, on human ABCB1 and ABCG2 in multidrug-resistant cancer cell lines. We discovered that at submicromolar concentrations, sitravatinib re-sensitizes ABCB1- and ABCG2-overexpressing multidrug-resistant cancer cells to chemotherapeutic drugs. We found that sitravatinib blocks the drug efflux function of ABCB1 and ABCG2 in a concentration-dependent manner but does not significantly alter the protein expression of ABCB1 or ABCG2 in multidrug-resistant cancer cells. In conclusion, we reveal a potential drug repositioning treatment option for multidrug-resistant cancers by targeting ABCB1 and ABCG2 with sitravatinib and should be further investigated in future clinical trials.

Keratinocytes apoptosis contributes to crizotinib induced-erythroderma

Crizotinib is a multi-target receptor tyrosine kinase inhibitor which is of great importance for the management of ALK-rearranged non-small cell lung cancer (NSCLC) patients. Serious erythroderma and toxic epidermal necrolysis have been reported associated with crizotinib treatment. The underlying mechanisms have not been examined. In this study, we tested the toxicity of crizotinib on immortal human keratinocytes (HaCaT) and human primary keratinocytes. We found that crizotinib directly cause cytotoxic on these two cells, which could be the explanation of the clinical characteristic of pathology. Apoptosis was observed and Z-VAD-FMK, a pan-caspase inhibitor can almost totally reverse the apoptosis induction effect of crizotinib. However, mitochondrial dysfunction and DNA damage were not involved in crizotinib-induced apoptosis, indicating the intrinsic apoptosis pathway have no connection with this cutaneous toxicity. Further studies showed that crizotinib significantly increased cleaved-caspase-8, a signaling protein of extrinsic apoptosis pathway, in a concentration and time-dependent manner. Moreover, we found the targets of crizotinib were not involved in HaCaT cells apoptosis. Collectively, our findings first report keratinocytes apoptosis is the key cause of crizotinib-induced cutaneous toxicity. We also reveal crizotinib induce apoptosis through the extrinsic apoptosis pathway due to detected up-regulated cleaved-caspase-8. Meanwhile, the apoptosis is independent of mitochondrial dysfunction, DNA damage and related drug targets inhibition.

Dovitinib Triggers Apoptosis and Autophagic Cell Death by Targeting SHP-1/p-STAT3 Signaling in Human Breast Cancers.

Breast cancer is the most common cancer and the leading cause of cancer deaths in women worldwide. The rising incidence rate and female mortality make it a significant public health concern in recent years. Dovitinib is a novel multitarget receptor tyrosine kinase inhibitor, which has been enrolled in several clinical trials in different cancers. However, its antitumor efficacy has not been well determined in breast cancers. Our results demonstrated that dovitinib showed significant antitumor activity in human breast cancer cell lines with dose- and time-dependent manners. Downregulation of phosphor-(p)-STAT3 and its subsequent effectors Mcl-1 and cyclin D1 was responsible for this drug effect. Ectopic expression of STAT3 rescued the breast cancer cells from cell apoptosis induced by dovitinib. Moreover, SHP-1 inhibitor reversed the downregulation of p-STAT3 induced by dovitinib, indicating that SHP-1 mediated the STAT3 inhibition effect of dovitinib. In addition to apoptosis, we found for the first time that dovitinib also activated autophagy to promote cell death in breast cancer cells. In conclusion, dovitinib induced both apoptosis and autophagy to block the growth of breast cancer cells by regulating the SHP-1-dependent STAT3 inhibition.

CX1003 quantification by ultra-performance LC-MS/MS in human plasma and its application to a pharmacokinetic study in solid tumor patients.

Aim: CX1003 is a novel multitargeted receptor tyrosine kinase inhibitor targeting cancer patients with relapsed or metastatic malignant solid tumors. The study aimed to develop a robust and rapid assay approach to quantify CX1003 in human plasma. Methodology & results: Samples of plasma were purified by SPE where the diluted eluates were then separated by a Waters Acquity CSH C18 column and thereafter detected using positive electrospray ionization via an ultra performance LC-MS/MS. Conclusion: The method to quantify CX1003 in human plasma was first exploited and validated with good sensitivity and specificity, and successfully fulfilled the requirement of the first-in-human clinical pharmacokinetic study of CX1003 in Chinese patients with relapsed or metastatic malignant solid tumors.

SQSTM1/p62 loss reverses the inhibitory effect of sunitinib on autophagy independent of AMPK signaling

Sunitinib (ST), a multitargeted receptor tyrosine kinase inhibitor, has been demonstrated to be effective for the treatment of renal carcinoma. It has been reported that ST is involved in the mediation of autophagy; however, its regulatory role in the autophagic process remains controversial. Furthermore, the mechanism by which activated AMP-activated protein kinase (AMPK) negatively regulates autophagy remains nearly unexplored. In the present study, we revealed that ST inhibited AMPK activity and regulated autophagy in a cell type- and dose-dependent manner. In a number of cell lines, ST was demonstrated to inhibit H2O2-induced autophagy and the phosphorylation of acetyl-CoA carboxylase (ACC), whereas alone it could block the autophagic flux concurrent with increased expression of p62. An immunoprecipitation assay revealed that LC3 directly interacted with p62, whereas ST increased punctate LC3 staining, which was well colocalized with p62. Taken together, we reveal a previously unnoticed pathway for ST to regulate the autophagic process, and p62, although often utilized as a substrate in autophagy, plays a critical role in regulating the inhibition of ST in both basal and induced autophagy.

A phase I study investigating the absorption, metabolism, and excretion of [14C] anlotinib in patients with advanced refractory solid tumors.

e14701 Background: Anlotinib is a novel oral multi-targeted receptor tyrosine kinase inhibitor, which selectively inhibits VEGFR2/3, FGFR1-4, PDGFR α/β, c-Kit, and Ret, and has shown antitumor activity in patients with advanced refractory solid tumors. The human plasma pharmacokinetics of anlotinib have been described previously, but detailed analyses of the absorption, metabolism and excretion pathways of anlotinib have not yet been published. Methods: Six male patients were divided into two groups, one group included two patients was performed by 13.51mg Anlotinib hydrochloride and 0.64 mg/80 μCi [14C] anlotinib hydrochloride and the rest four patients in another group received 13.19mg anlotinib hydrochloride and 0.96mg/120 μCi [14C] anlotinib hydrochloride, followed by collection of blood, urine, and fecal samples. The primary outcomes of study were absorption, metabolism, and excretion of [14C] anlotinib and the second outcomes were efficacy and safety. Results: In plasma, the average time of total plasma radioactivity peak (Tmax) was 4.42h and the average peak concentration (Cmax) was 18.80 ng Eq./g. The average value of AUC last was 4071 h∙ng Eq./g, AUC0-∞ was 13555 h∙ng Eq./g, and MRT0-t was 145h. The average recovery rate of total radioactivity in urine and feces was 62.03%. Prototype drugs and metabolites were mainly excreted through feces, accounting for 48.52% of the administered dose, otherwise rine excretion accounted for 13.51%. The liver and kidney were the main drug excretion organs. Five patients developed adverse reactions, and one person developed SAE. Three of study population were assessed as stable disease (SD), two with partial response (PR), and one had progressive disease (PD). Conclusions: Anlotinib showed a favourable pharmacokinetic profile with high absolute bioavailability and an extensive hepatic metabolism. The adverse events and efficacy were as expected. Clinical trial information: CTR20160329.

Systematic Review on Cytotoxic and Anticancer Potential of N-Substituted Isatins as Novel Class of Compounds Useful in Multidrug-Resistant Cancer Therapy: In Silico and In Vitro Analysis.

As the emergence of resistance to clinical cancer treatments poses a significant problem in cancer management, there is a constant need to explore novel anticancer agents which have the ability to overcome multidrug resistance (MDR) mechanisms. The search for the development of novel isatin-based antitumor agents accelerated after the approval by the Food and Drug Administration (FDA) of sunitinib malate, a C-3 isatin derivative, as a multitargeted receptor tyrosine kinase inhibitor. However, it is interesting to note that, over the last decade, various N-substituted analogs of isatin with intact carbonyl functionalities have been found to show more promising anticancer potential than its C-3 derivatives. Microtubule-targeting agents are a class of anticancer drugs which affect mitosis by targeting microtubules and suppressing their dynamic behavior. This review presents a systematic compilation of the invitro cytotoxic and anticancer properties of various N-substituted isatins and illustrates their mechanism of action to overcome MDR by acting as microtubule-destabilizing agents. Predictions of the biological activities and cytotoxic effects of potential N-substituted isatins against various cancer cell lines have also been performed using the PASS computer-aided drug discovery program. Findings from such invitro and insilico studies will act as a guide for the development of structure-activity relationship and will facilitate the design and exploration of more potent analogs of isatin with high potency and lower side effects for treatment of drug-resistant cancer. Mechanism of action of N-substituted isatin as microtubule-destabilizing agent on tumor cells. N-Substituted isatins bind to colchicine binding site on β-tubulin, which inhibits microtubule polymerization and thereby destabilizes microtubule dynamics, resulting in mitotic arrest leading to tumor cell growth suppression.

Upregulation of phosphoinositide 3-kinase prevents sunitinib-induced cardiotoxicity in vitro and in vivo.

Sunitinib (SNT) is a multi-targeted receptor tyrosine kinase inhibitor that has been approved by the FDA for cancer therapy. However, its cardiotoxicity has limited the clinical applicability with no effective therapeutic approach available. As a broadband kinase inhibitor, the function of several kinases that are essential to cardiac function might also be affected by SNT, such as calmodulin-dependent protein kinase (CaMKII), cyclic-AMP-dependent protein kinases (PKA), AMP-activated protein kinase (AMPK), and phosphoinositide 3 kinase (PI3K). In this study, we investigated whether SNT-induced cardiotoxicity could be prevented by blocking SNT-induced alteration in the corresponding signaling pathways. In human induced pluripotent stem cell-derived cardiomyocytes, SNT (0.5-20µmol/L) inhibited contractility of cardiomyocytes in a concentration-dependent manner, and the inhibitory effect was prevented either by PIP3 (1µmol/L) application or PI3K overexpression. On the contrary, the CaMKII inhibitor KN-93 (50nmol/L), PKA inhibitor H89 (1µmol/L), and AMPK activators metformin (2mmol/L) and 5-aminoimidazole-4-carboxamide 1-b-D-ribofuranoside (2mmol/L) presented negligible effects. Oral SNT administration (40mg/kg/day) in mice progressively decreased the PI3K activity and cardiac function in 2weeks with a significant decrease in the expression and activity of Cav1.2 and SERCA. Cardiac-specific PI3K overexpression through adeno-associated virus 9-mediated gene delivery in mice prevented SNT-induced reduction in cardiac function, calcium transient, calcium current, and Cav1.2 expression. In summary, our data indicate that increased PI3K activity is protective against SNT-induced calcium mishandling and contractile dysfunction. Cardiac-specific PI3K activation could be an effective therapeutic approach to treat SNT cardiotoxicity in patients with cancer.

Improved Cancer Immunochemotherapy via Optimal Co-delivery of Chemotherapeutic and Immunomodulatory Agents.

It is highly demanded and still a big challenge to develop an effective formulation for immunochemotherapy against advanced tumors. We have previously reported a PEG-NLG-based immunostimulatory nanocarrier (PEG2k-Fmoc-NLG919) for co-delivery of an IDO1 inhibitor (NLG919) and a chemotherapeutic agent (paclitaxel, PTX). Although antitumor immune responses were enhanced with a PTX-loaded nanocarrier, the accumulation of myeloid-derived suppressor cells (MDSCs) was also significantly increased, which may limit the overall efficacy of therapy. In the present work, we developed an improved dual-functional nanocarrier (PEG5k-Fmoc-NLG2) to co-load PTX and sunitinib (SUN, a multitarget receptor tyrosine kinase inhibitor) for improved cancer immunochemotherapy. We found that the recruited MDSCs negatively impacted the overall antitumor activity of the PTX-loaded PEG-NLG nanocarrier. Mechanistic study suggests that this is likely attributed to the PTX-mediated induction of a number of chemokines that are involved in the recruitment of MDSCs. We have further shown that the induction of these chemokines was drastically blocked by SUN. Co-delivery of PTX and SUN via the PEG5k-Fmoc-NLG9192 nanocarrier led to a further improvement in the therapeutic efficacy with a concomitant reduction in MDSCs.

Anlotinib induces hepatocellular carcinoma apoptosis and inhibits proliferation via Erk and Akt pathway

Although anlotinib, a multi-targeted receptor tyrosine kinase inhibitor has been reported have antitumor effects in many preclinical and clinical trials, little is known about its effect on hepatocellular carcinoma (HCC). Here, we have shown the antitumor effects of anlotinib on HCC. Data indicated that anlotinib application significantly inhibited HCC cell viability, proliferation, colony formation, and prompted apoptosis in vitro. Furthermore, animal experiments also illustrated that anlotinib alleviated HCC progression. Mechanically, we demonstrated that anlotinib treatment downregulated the anti-apoptotic protein Bcl-2 and Survivin, but upregulated pro-apoptotic molecule Bax, which accounts for its therapeutic effect on HCC. Pathway analysis has shown decreased phosphorylation levels of Erk and Akt. Together, this study suggests that anlotinib may have a direct antitumor progression effect on HCC by inhibiting Bcl-2 and Survivin expression, promoting Bax expression via inactivating Erk and Akt pathways and could be a promising agent treating HCC.

Preclinical development of sunitinib and nivolumab in osteosarcoma and synovial sarcoma: In vitro functional studies.

e14543Background: The multi-targeted receptor tyrosine kinase inhibitors (TKIs) sunitinib and nivolumab (anti-PD-1) have shown remarkable antitumor activity. Preliminar clinical data on TKIs and an...

Amplification of Oncolytic Vaccinia Virus Widespread Tumor Cell Killing by Sunitinib through Multiple Mechanisms.

Oncolytic viruses pose many questions in their use in cancer therapy. In this study, we assessed the potential of mpJX-594 (mouse-prototype JX-594), a replication-competent vaccinia virus administered by intravenous injection, to target the tumor vasculature, produce immune activation and tumor cell killing more widespread than the infection, and suppress invasion and metastasis. These actions were examined in RIP-Tag2 transgenic mice with pancreatic neuroendocrine tumors that developed spontaneously and progressed as in humans. mpJX-594 initially infected tumor vascular endothelial cells, leading to vascular pruning and prolonged leakage in tumors but not in normal organs; parallel effects were observed in U87 gliomas. Viral infection spread to tumor cells, where tumor cell killing was much more widespread than the infection. Widespread tumor cell killing at 5 days was prevented by depletion of CD8+ T lymphocytes and did not require GM-CSF, as mpJX-594 variants that expressed human, mouse, or no GM-CSF produced equivalent amounts of killing. The antivascular, antitumor, and antimetastatic effects of mpJX-594 were amplified by concurrent or sequential administration of sunitinib, a multitargeted receptor tyrosine kinase inhibitor. These effects were not mimicked by selective inhibition of VEGFR2 despite equivalent vascular pruning, but were accompanied by suppression of regulatory T cells and greater influx of activated CD8+ T cells. Together, our results showed that mpJX-594 targets tumor blood vessels, spreads secondarily to tumor cells, and produces widespread CD8+ T-cell-dependent tumor cell killing in primary tumors and metastases, and that these effects can be amplified by coadministration of sunitinib.Significance: These findings reveal multiple unrecognized features of the antitumor properties of oncolytic vaccinia viruses, all of which can be amplified by the multitargeted kinase inhibitor sunitinib. Cancer Res; 78(4); 922-37. ©2017 AACR.

Anti-tumor efficacy of oncolytic reovirus against gastrointestinal stromal tumor cells.

Imatinib, a multitargeted receptor tyrosine kinase inhibitor, is used as the standard initial therapy against inoperable gastrointestinal stromal tumor (GIST). However, GIST can acquire resistance to imatinib within several years of therapy. The development of oncolytic reovirus as an anticancer agent has expanded to many clinical trials for various tumors. Here, we investigated whether reovirus has antitumor activity against GIST cells in the setting of imatinib sensitivity in vitro and in vivo. Cell proliferation and apoptosis assays were performed using a human GIST cell line, GIST-T1, and imatinib-resistant GIST (GIST-IR) cells that we established. The molecular pathways responsible for cell damage by reovirus were explored using PCR-arrays and Western blots. Reovirus significantly induced apoptotic cell death in GIST-T1 and GIST-IR cells in vitro, despite differences in the activation of receptor tyrosine kinase pathways between GIST-T1 and GIST-IR. Molecular assays indicated the possibility that reovirus induces apoptotic cell death via Fas signaling. Furthermore, in vivo mouse tumor xenograft models demonstrated a significant anti-tumor effect of reovirus on both GIST-T1 and GIST-IR cells. Our results demonstrate the therapeutic potential of reovirus against GIST.

Synthesis and biological evaluation of novel 6,11-dihydro-5H-benzo[e]pyrimido- [5,4-b][1,4]diazepine derivatives as potential c-Met inhibitors

Over expression of c-Met tyrosine kinase is known to promote tumorigenesis and metastasis, as well as to cause therapeutic resistance. Herein a series of novel 6,11-dihydro-5H-benzo[e]pyrimido[5,4-b][1,4]diazepine derivatives were designed, synthesised and evaluated for their c-Met kinase inhibition. Compounds 17e, 17f, 18a, and 18b were further examined for their anti-proliferative activities against four typical cancer cell lines (PC-3, Panc-1, HepG2, and Caki-1). The promising compound 17f was identified as a multi-target receptor tyrosine kinase inhibitor, which also displayed favourable pharmacokinetic properties in rats, had an acceptable safety profile in preclinical studies, and significant anti-tumour activity in the Caki-1 tumour xenograft model.

A novel self-nanoemulsifying formulation for sunitinib: Evaluation of anticancer efficacy

Breast cancer is the top cancer and a main cause of death among women. The incidence of this cancer is increasing in the world. Sunitinib maleate is an oral, small-molecule, multi-targeted receptor tyrosine kinase inhibitor that inhibits tumor cell proliferation and angiogenesis, and has been administrated as an anticancer drug. Self-nanoemulsifying drug delivery system (SNEDDS) is an isotopic mixture of an oil, a surfactant and usually a co-surfactant, which can spontaneously form fine oil-in-water nanoemulsion in aqueous media. Here, a SNEDDS composed of 15% ethyl oleate (as an oil phase), 30% tween 80 (as a surfactant), and 55% PEG 600 (as a co-surfactant) was prepared and developed as a carrier for sunitinib. The average droplet size of sunitinib-loaded SNEDDS was 29.5±6.3nm with a stability of more than one month. Sunitinib release from SNEDDS was enhanced accompanied by a controlled dissolution of the drug. Cytotoxicity studies on 4T1 and MCF-7 cell lines indicated a toxicity enhancement in sunitinib by SNEDDS. To inspect the bioavailability of the drug-loaded SNEDDS after oral administration with a dose of 50mgkg−1, the maximum plasma concentration and the mean area under the plasma concentration-time curve were measured. It was found that these parameters were increased 1.45- and 1.24-times respectively, compared to a drug suspension.

Correlation Between the Tyrozinkinazine Inhibitor Sunitinib - Dose, Schedule of Administration and Adverse Events

Sunitinib, a multi-targeted receptor tyrosine kinase inhibitor, has demonstrated survival benefit in patients with metastatic renal cell carcinoma (mRCC) and is generally well tolerated with most adverse events, manifesting as mild to moderate in severity. The most frequent related adverse events include hand-foot syndrome (HFS), hypertension, proteinuria, cardiac toxicities, myelosuppression, fatigue/asthenia, hypothyroidism, diarrhea and hepatotoxicity. The study aims to determine incidence of adverse events among patients with metastatic renal cell carcinoma (mRCC) treated Sunitinib within five years from 2010 to 2015 and comparing the results with data from literature. The study included a total of 56 patients treated with Sunitinib, with a dose of 50 mg (Schedule 4/2). Due to adverse events and individual safety and tolerability, at the indication of the personal clinician, 11 patients needed dose reduction, with a continuous dose of 37.5 mg, daily and 28 patients continued the dose of 50 mg taken daily, on a different schedule (2/1 schedule). The most important toxicities were anemia, leukopenia, thrombocytopenia, gastrointestinal effects (diarrhea), fatigue and hypertension. After dose reduction or modified schedule the incidence of the most frequent toxicities (HFS, leukopenia, thrombocytopenia and fatigue) decreased, but hypertension was still observed in 30% of patients. The results are similar with data from literature. Early identification of individuals at risk and monitoring patients during Sunitinib treatment is very important and it can facilitate early intervention with prophylactic measures or supportive treatment, thus increasing quality of life and adherence to treatment. Further studies need to establish which targeted population can benefit the most from adjusted regimens and to correlate them with prognostic factors for survival.