Safety, pharmacokinetic, and antitumor activity of SU11248, a novel oral multitarget tyrosine kinase inhibitor, in patients with cancer

Sunitinib promotes myogenic regeneration and mitigates disease progression in the mdx mouse model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a lethal, muscle degenerative disease causing premature death of affected children. DMD is characterized by mutations in the dystrophin gene that result in a loss of the dystrophin protein. Loss of dystrophin causes an associated reduction in proteins of the dystrophin glycoprotein complex, leading to contraction-induced sarcolemmal weakening, muscle tearing, fibrotic infiltration and rounds of degeneration and failed regeneration affecting satellite cell populations. The α7β1 integrin has been implicated in increasing myogenic capacity of satellite cells, therefore restoring muscle viability, increasing muscle force and preserving muscle function in dystrophic mouse models. In this study, we show that a Food and Drug Administration (FDA)-approved small molecule, Sunitinib, is a potent α7 integrin enhancer capable of promoting myogenic regeneration by stimulating satellite cell activation and increasing myofiber fusion. Sunitinib exerts its regenerative effects via transient inhibition of SHP-2 and subsequent activation of the STAT3 pathway. Treatment of mdx mice with Sunitinib demonstrated decreased membrane leakiness and damage owing to myofiber regeneration and enhanced support at the extracellular matrix. The decreased myofiber damage translated into a significant increase in muscle force production. This study identifies an already FDA-approved compound, Sunitinib, as a possible DMD therapeutic with the potential to treat other muscular dystrophies in which there is defective muscle repair.

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.

Small molecules, big impact: 20 years of targeted therapy in oncology

The identification of molecular targets and the growing knowledge of their cellular functions have led to the development of small molecule inhibitors as a major therapeutic class for cancer treatment. Both multitargeted and highly selective kinase inhibitors are used for the treatment of advanced treatment-resistant cancers, and many have also achieved regulatory approval for early clinical settings as adjuvant therapies or as first-line options for recurrent or metastatic disease. Lessons learned from the development of these agents can accelerate the development of next-generation inhibitors to optimise the therapeutic index, overcome drug resistance, and establish combination therapies. The future of small molecule inhibitors is promising as there is the potential to investigate novel difficult-to-drug targets, to apply predictive non-clinical models to select promising drug candidates for human evaluation, and to use dynamic clinical trial interventions with liquid biopsies to deliver precision medicine.

A 2/1 Sunitinib Dosing Schedule Provides Superior Antitumor Effectiveness and Less Toxicity Than a 4/2 Schedule for Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: The standard sunitinib schedule to treat metastatic renal cell carcinoma (mRCC) is 4 weeks on/2 weeks off (4/2). However, some studies revealed intolerable adverse events (AEs) in patients on this schedule. An alternative schedule, 2 weeks on/1 week off (2/1), may overcome this issue. This meta-analysis was performed to compare the effectiveness and toxicity between the 2/1 and 4/2 sunitinib dosing schedules.

Methods: We acquired relevant studies by searching PubMed, ScienceDirect, the Cochrane Library, Scopus, Ovid MEDLINE, Embase, Web of Science, and Google Scholar. Our main endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and AEs.

Results: We identified 9 medium- and high-quality studies. Both schedules were effective for mRCC, with comparable OS and similar ORR. However, the 2/1 schedule had better PFS (hazard ratio (HR) = 0.81, 95% confidence interval [CI]: 0.66–0.99, P = 0.04), higher DCR [risk rate (RR) = 1.22, 95% CI: 1.01–1.47, P = 0.04] and fewer dosage interruptions (RR = 0.60, 95% CI: 0.43–0.84, P = 0.003). Additionally, the 2/1 schedule elicited fewer specific severe AEs, including thrombocytopenia/platelet disorder, hand-foot syndrome, hypertension, and fatigue. In our subanalysis, PFS was better among East Asians using the 2/1 schedule than among other populations (HR= 0.75, 95% CI: 0.58–0.98, P = 0.03), and patients administered an initial dosage of 50 mg/d on the 2/1 schedule had superior PFS (HR = 0.76, 95% CI: 0.59–0.97, P = 0.03) than those others.

Conclusions: These findings suggest that the 2/1 schedule is more suitable for mRCC than 4/2, due to superior PFS, better DCR and fewer AEs. Nevertheless, more large-scale studies with good quality are needed.

The effect of adenosine triphosphate on sunitinib-induced cardiac injury in rats

In this study, we aimed to show the effect of adenosine 5'-triphosphate (ATP) on sunitinib-induced cardiac injury in rats. The rats (n = 30) were divided equally into three groups as sunitinib group (SG), sunitinib plus ATP group (SAG), and healthy group (HG); 2 mg/kg ATP was injected intraperitoneally (ip) to the SAG group. Same volume normal saline as solvent was administered ip to the other two groups. After 1 h, 25 mg/kg sunitinib was applied orally via catheter to stomach in the SAG and SG groups. This procedure was repeated once daily for 5 weeks. At the end of this period, all animals were sacrificed and their cardiac tissue was removed. Malondialdehyde (MDA), total glutathione (tGSH), tumor necrosis factor α (TNF-α), and nuclear factor κB (NF-κB) levels in rats' cardiac tissues and troponin I (Tp-I) levels in rats' blood samples were evaluated. Histopathological analysis was also performed in cardiac tissues of the animals. MDA, TNF-α, NF-κB, and Tp-I levels were higher in the SG group compared to the SAG and HG groups (p < 0.001). tGSH levels of the SG group were lower than the SAG and HG groups (p < 0.001). The structure and morphology of cardiac muscle fibers and blood vessels were normal in the control group. In the SG group, obvious cardiac muscle tissue damage with dilated myofibers, locally atrophic myofibers, and congested blood vessels were observed. In the SAG group, marked amelioration in these findings was observed. We showed this for the first time that ATP administration exerts a protective effect against cardiac effects of sunitinib.

The efficacy of axitinib as a first-line treatment for metastatic renal cell carcinoma

AIM

To evaluate predictive factors which associated with oncological outcomes to first-line axitinib for metastatic renal cell carcinoma (mRCC).

METHODS

A retrospective chart review was conducted patients who had been treated with axitinib as first-line therapy for the treatment of mRCC from September 2013 to February 2018. Axitinib was given by single daily oral administration at a dose of 10 mg, which was reduced according to adverse events (AEs). We investigated progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and AEs.

RESULTS

Thirty-eight mRCC patients were enrolled. The median follow-up duration of axitinib treatment was 11.3 months (range = 1.0-56.9). ORR was 28.9%. Median PFS and OS was 12.8, and 17.9 months, respectively. In univariate analysis, baseline lactate dehydrogenase (LDH), neutrophil, corrected calcium (Ca), platelets (Plt) and time from diagnosis were selected as potential predictive factors. Multivariate Cox's proportional hazards model analysis showed that the number of risk factors were associated with PFS (P = 0.03) and OS (P = 0.02).

CONCLUSION

Baseline LDH, neutrophil, Ca, Plt and time from diagnosis are predictive factors for both PFS and OS in first-line treatment with axitinib for metastatic renal cell carcinoma.

Thyroid profile during the alternative Sunitinib dosing 2/1 schedule in metastatic renal cell carcinoma

PURPOSE

Hypothyroidism is a common side effect of Sunitinib (SUN) treatment in metastatic renal cell carcinoma (mRCC) patients. We aimed to evaluate thyroid profile during the alternative 2/1 SUN treatment schedule and to assess the predictive value of hypothyroidism in terms of survival.

METHODS

We performed a prospective observational study enrolling 42 consecutive mRCC patients starting first-line alternative SUN dosing 2/1 schedule. Thyroid function was assessed at baseline and during the first three SUN cycles (1 cycle = 6 weeks = 2 ON/1 OFF + 2 ON/1 OFF), and then after 6 and 12 months. Thyroid ultrasound was performed at baseline and after 3, 6, and 12 months.

RESULTS

Subclinical hypothyroidism developed in 24% of patients during the first cycle; in other 24% in the second cycle and in 14% in the third cycle. The highest TSH values were reached during the second cycle, ON phase (6.58 ± 5.74 μI U/l). We observed a reduction in thyroid size, in echogenicity and in parenchymal perfusion in all patients. Progression-free survival (PFS) tended to be longer in patients with TSH ≥ 5 μI U/ml during the second cycle (p = 0.069). TSH level was an independent risk factor for PFS in men (p = 0.009) but not in women (p = 0.285).

CONCLUSIONS

This is the first study investigating functional and morphological effects on thyroid during the alternative 2/1 SUN schedule in mRCC patients. We detected an early onset of subclinical hypothyroidism, observing the association between TSH ≥ 5 μI U/ml and: (i) longer PFS in men; (ii) progressive decrease of thyroid size in absence of significant changes in autoimmune thyroid profile.

[Acute Acalculous Cholecystitis Associated with Sunitinib Treatment for Renal Cell Carcinoma]

A 64-year-old man was treated with sunitinib as a first-line therapy for metastatic renal cell carcinoma. He was given oral sunitinib in cycles of 50 mg once daily for 2 weeks followed by a week off. During the 5th week of treatment right upper quadrant pain developed, but this resolved spontaneously during the 6th week (off treatment). However, on the 8th week of treatment, he was admitted to hospital because the acute right upper quadrant pain recurred with nausea, vomiting, and fever. Acute acalculous cholecystitis was then diagnosed by ultrasonography and CT. In addition, his laboratory findings indicated disseminated intravascular coagulation. Accordingly, sunitinib therapy was discontinued and broad-spectrum antibiotics initiated. He subsequently recovered after emergent percutaneous cholecystostomy. His Naranjo Adverse Drug Reaction Probability Scale score was 7, indicaing a probable association of the event with sunitinib. Suspicion of sunitinib-related acute cholecystitis is required, because, although uncommon, it can be life-threatening.

Mechanistic Pharmacokinetic/Pharmacodynamic Model of Sunitinib and Dopamine in MCF-7/Adr Xenografts: Linking Cellular Heterogeneity to Tumour Burden

The self-renewal and differentiation of cancer stem-like cells (CSCs) leads to cellular heterogeneity, causing one of the greatest challenges in cancer therapy. Growing evidence suggests that CSC-targeting therapy enhances the effect of concomitant antitumour therapy. To gain an in-depth understanding of this enhanced effect, the kinetic profile of estimated CSC frequency (the fraction of CSCs in tumour) was evaluated for in vivo characterization of cellular heterogeneity using sunitinib and dopamine as a paradigm combination therapy. Female MCF-7/Adr xenografted Balb/c nude mice were treated with sunitinib (p.o., 20 mg/kg) and dopamine (i.p., 50 mg/kg), alone or in combination. Estimated CSC frequency and tumour size were measured over time. Mechanistic PK/PD modelling was performed to quantitatively describe the relationship between drug concentration, estimated CSC frequency and tumour size. Sunitinib reduced tumour size by inducing apoptosis of differentiated tumour cells (DTCs) and enriched CSCs by stimulating its proliferation. Dopamine exhibited anti-CSC effects by suppressing the capacity of CSCs and inducing its differentiation. Simulation and animal studies indicated that concurrent administration was superior to sequential administration under current experimental conditions. Alongside tumour size, the current study provides mechanistic insights into the estimation of CSC frequency as an indicator for cellular heterogeneity. This forms the conceptual basis for in vivo characterization of other combination therapies in preclinical cancer studies.

Kinase Inhibitor Treatment of Patients with Advanced Cancer Results in High Tumor Drug Concentrations and in Specific Alterations of the Tumor Phosphoproteome

Identification of predictive biomarkers for targeted therapies requires information on drug exposure at the target site as well as its effect on the signaling context of a tumor. To obtain more insight in the clinical mechanism of action of protein kinase inhibitors (PKIs), we studied tumor drug concentrations of protein kinase inhibitors (PKIs) and their effect on the tyrosine-(pTyr)-phosphoproteome in patients with advanced cancer. Tumor biopsies were obtained from 31 patients with advanced cancer before and after 2 weeks of treatment with sorafenib (SOR), erlotinib (ERL), dasatinib (DAS), vemurafenib (VEM), sunitinib (SUN) or everolimus (EVE). Tumor concentrations were determined by LC-MS/MS. pTyr-phosphoproteomics was performed by pTyr-immunoprecipitation followed by LC-MS/MS. Median tumor concentrations were 2–10 µM for SOR, ERL, DAS, SUN, EVE and >1 mM for VEM. These were 2–178 × higher than median plasma concentrations. Unsupervised hierarchical clustering of pTyr-phosphopeptide intensities revealed patient-specific clustering of pre- and on-treatment profiles. Drug-specific alterations of peptide phosphorylation was demonstrated by marginal overlap of robustly up- and downregulated phosphopeptides. These findings demonstrate that tumor drug concentrations are higher than anticipated and result in drug specific alterations of the phosphoproteome. Further development of phosphoproteomics-based personalized medicine is warranted.

Imatinib, sunitinib and pazopanib: From flat-fixed dosing towards a pharmacokinetically guided personalized dose

Tyrosine kinase inhibitors (TKIs) are anti‐cancer drugs that target tyrosine kinases, enzymes that are involved in multiple cellular processes. Currently, multiple oral TKIs have been introduced in the treatment of solid tumours, all administered in a fixed dose, although large interpatient pharmacokinetic (PK) variability is described. For imatinib, sunitinib and pazopanib exposure‐treatment outcome (efficacy and toxicity) relationships have been established and therapeutic windows have been defined, therefore dose optimization based on the measured blood concentration, called therapeutic drug monitoring (TDM), can be valuable in increasing efficacy and reducing the toxicity of these drugs.

In this review, an overview of the current knowledge on TDM guided individualized dosing of imatinib, sunitinib and pazopanib for the treatment of solid tumours is presented. We summarize preclinical and clinical data that have defined thresholds for efficacy and toxicity. Furthermore, PK models and factors that influence the PK of these drugs which partly explain the interpatient PK variability are summarized. Finally, pharmacological interventions that have been performed to optimize plasma concentrations are described. Based on current literature, we advise which methods should be used to optimize exposure to imatinib, sunitinib and pazopanib.

An HPLC method for simultaneous quantification of sunitinib and its active metabolite, SU12662, using hydrophilic interaction chromatography principle

Aim: To develop a sensitive HPLC method for the quantitation of sunitinib (SU) and its active metabolite N-desethyl-sunitinib (SU12662) in human plasma. Materials & methods: The analytes were extracted from 500 μl of plasma using liquid–liquid extraction followed by protein precipitation. Chromatographic separation of two analytes and internal standard, vandetenib, was achieved on a hydrophilic interaction liquid chromatography analytical column using a gradient program. Calibration curves were linear over the range of 10–250 ng/ml for both SU and SU12662. The method was validated according to the US FDA guidelines for bioanalytical methods. Accuracy of the method at 10 ng/ml for SU and SU12662 was 8.7 and 6.7%, respectively, and precision was 10.18% and 17.3%, respectively. Conclusion: This method allows a specific, sensitive and reliable determination of SU and SU12662 in human plasma in a single analytical run which makes it useful for therapeutic drug monitoring.

Copper-catalyzed (4+1) and (3+2) cyclizations of iodonium ylides with alkynes

The copper(ii)-catalyzed (4+1) cyclizations and copper(i)-catalyzed (3+2) cycloadditions of iodonium ylides and alkynes have been successfully developed. The corresponding highly functionalized heterocyclic products were prepared conveniently.

Voltammetric responses at modified electrodes and aggregation effects of two anticancer molecules: irinotecan and sunitinib

Voltammetric analyses of two anticancer molecules at modified electrodes and influence of aggregate formation on their differential pulse voltammetry (DPV) responses.

Medical oncology management of advanced hepatocellular carcinoma 2019: a reality check

In terms of global cancer-related deaths, hepatocellular carcinoma (HCC) has the fourth highest mortality rate. Up until 2017, treatment of advanced HCC was largely limited to sorafenib, an oral tyrosine kinase inhibitor, with little to no success in the development of alternative treatment options. However, in the past two years, there has been an unprecedented increase in both the number and type of treatment options available for HCC. As of 2019, the US FDA has approved four oral tyrosine kinase inhibitors, two immune checkpoint inhibitors, and one anti-angiogenesis antibody for the treatment of HCC. Even with this new variety, systemic treatment of advanced HCC remains largely unsatisfactory, and the median survival rate stands at approximately one year. The expected breakthrough of using immune checkpoint inhibitors in advanced HCC did not materialize in 2019. The use of immune checkpoint inhibitors in conjunction with oral tyrosine kinase inhibitors or anti-angiogenesis medications is the current clinical research trend, the results of which are eagerly anticipated. Despite limited progress in survival, HCC research is currently experiencing a period of growth and innovation, and there is hope for significant advances in the treatment of advanced HCC as the field continues to develop.

Pharmacodynamics, clinical findings and approval status of current and emerging tyrosine-kinase inhibitors for pancreatic neuroendocrine tumors

Introduction: Pancreatic neuroendocrine tumors (panNETs) represent a rare group of malignancies. For decades, chemotherapy, somatostatin analogs and interferon represented the only systemic therapies; however, over the latest years, new options were registered, including Everolimus, Sunitinib (SUN), and Peptide Receptor Radionuclide Therapy.Areas covered: This review discusses the role of tyrosine kinase inhibitors (TKIs) in advanced panNETs.Expert opinion: TKIs showed an antiangiogenic and antiproliferative impact on advanced panNETs. Sunitinib is the only TKI currently available in clinical practice, having been approved on the basis of relevant results of a specific panNET phase III trial. New TKIs, such as Cabozantinib, Lenvatinib, Pazopanib, Surufatinib are still on investigation in panNETs. Although some phase II studies with the new TKIs yielded better PFS and RR compared with SUN, different study designs and tumor populations may have induced selection biases. However, it was reported that panNETs resistant to SUN could respond to a new TKI, indicating a possible further therapeutic line in this context. The global investigation plan of TKIs in panNETs is not homogeneous and it is difficult to understand what kind of development this can have in the near future for clinical practice.

Dermatologic conditions in women receiving systemic cancer therapy

As advances in cancer therapies have improved cancer-related survival, novel therapeutics have also introduced a variety of dermatologic toxicities, and an increased number of patients are living with these sequalae. Women with cancer in particular experience a spectrum of dermatologic conditions that affect their skin, hair, nail, and mucosal surfaces. Studies have shown that these toxic effects can significantly affect quality of life and alter a woman's self-image, cultural identity, femininity, sexuality, and mental health. In severe instances, dermatologic toxicities may even disrupt cancer therapy and can therefore affect overall survival and treatment response. In this article, we review the dermatologic adverse effects from traditional chemotherapy, targeted therapy, immune checkpoint inhibitors, and endocrine therapy that disproportionately affect women. The timely diagnosis and management of these dermatologic conditions is crucial in the multidisciplinary care of women with cancer.

Teaching an Old Molecule New Tricks: Drug Repositioning for Duchenne Muscular Dystrophy

: Duchenne muscular dystrophy (DMD) is one of the most severe forms of inherited muscular dystrophies. The disease is caused by the lack of dystrophin, a structurally essential protein; hence, a definitive cure would necessarily have to pass through some form of gene and/or cell therapy. Cell- and genetic-based therapeutics for DMD have been explored since the 1990s and recently, two of the latter have been approved for clinical use, but their efficacy is still very low. In parallel, there have been great ongoing efforts aimed at targeting the downstream pathogenic effects of dystrophin deficiency using classical pharmacological approaches, with synthetic or biological molecules. However, as it is always the case with rare diseases, R&D costs for new drugs can represent a major hurdle for researchers and patients alike. This problem can be greatly alleviated by experimenting the use of molecules that had originally been developed for different conditions, a process known as drug repurposing or drug repositioning. In this review, we will describe the state of the art of such an approach for DMD, both in the context of clinical trials and pre-clinical studies.

Reduction and Escalation in the Dose of Sunitinib Were Adequately Effective against Gastrointestinal Stromal Tumor of the Small Intestine

We herein report the first case in which an escalated dose of sunitinib was effective, even after dose reduction. A 64-year-old man with gastrointestinal stromal tumor of the small intestine discontinued adjuvant imatinib because of interstitial pneumonia. After two years, peritoneal recurrence was detected. Sunitinib was started at 50 mg/day for 4 weeks every 6 weeks, after which the dosage was reduced to 37.5 mg/day because of grade 1 gastritis, stomatitis, and a fever. Four months later, computed tomography showed progressive disease. As the adverse events were well-controlled by medication, we escalated the dose to 50 mg/day and achieved a partial response.

Synergistic Highly Potent Targeted Drug Combinations in Different Pheochromocytoma Models Including Human Tumor Cultures

There are no officially approved therapies for metastatic pheochromocytomas apart from ultratrace 131I-metaiodbenzylguanidine therapy, which is approved only in the United States. We have, therefore, investigated the antitumor potential of molecular-targeted approaches in murine pheochromocytoma cell lines [monocyte chemoattractant protein (MPC)/monocyte chemoattractant protein/3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)], immortalized mouse chromaffin Sdhb-/- cells, three-dimensional pheochromocytoma tumor models (MPC/MTT spheroids), and human pheochromocytoma primary cultures. We identified the specific phosphatidylinositol-3-kinase α inhibitor BYL719 and the mammalian target of rapamycin inhibitor everolimus as the most effective combination in all models. Single treatment with clinically relevant doses of BYL719 and everolimus significantly decreased MPC/MTT and Sdhb-/- cell viability. A targeted combination of both inhibitors synergistically reduced MPC and Sdhb-/- cell viability and showed an additive effect on MTT cells. In MPC/MTT spheroids, treatment with clinically relevant doses of BYL719 alone or in combination with everolimus was highly effective, leading to a significant shrinkage or even a complete collapse of the spheroids. We confirmed the synergism of clinically relevant doses of BYL719 plus everolimus in human pheochromocytoma primary cultures of individual patient tumors with BYL719 attenuating everolimus-induced AKT activation. We have thus established a method to assess molecular-targeted therapies in human pheochromocytoma cultures and identified a highly effective combination therapy. Our data pave the way to customized combination therapy to target individual patient tumors.

Naturally occurring cancers in pet dogs as pre-clinical models for cancer immunotherapy

Despite the significant progress in tumor prevention, early detection, diagnosis and treatment made over recent decades, cancer is still an enormous public health challenge all around the world, with the number of people affected increasing every year. A great deal of effort is therefore being devoted to the search for novel safe, effective and economically sustainable treatments for the growing population of neoplastic patients. One main obstacle to this process is the extremely low percentage of therapeutic approaches that, after successfully passing pre-clinical testing, actually demonstrate activity when finally tested in humans. This disappointing and expensive failure rate is partly due to the pre-clinical murine models used for in vivo testing, which cannot faithfully recapitulate the multifaceted nature and evolution of human malignancies. These features are better mirrored in natural disease models, i.e., companion animals affected by cancers. Herein, we discuss the relevance of spontaneous canine tumors for the evaluation of the safety and anti-tumor activity of novel therapeutic strategies before in-human trials, and present our experience in the development of a vaccine that targets chondroitin sulphate proteoglycan (CSPG)4 as an example of these comparative oncology studies.

A new high-performance liquid chromatography-tandem mass spectrometry method for the determination of sunitinib and N-desethyl sunitinib in human plasma: Light-induced isomerism overtaking towards therapeutic drug monitoring in clinical routine

Sunitinib is approved for advanced renal cell cancer, imatinib-resistant or -intolerant gastrointestinal stromal tumors and pancreatic neuroendocrine cancers. It is prescribed at a fixed dose but its plasma exposure shows large inter-individual variations. Taking into account the narrow therapeutic window and the positive exposure-efficacy relationship, there is a robust rationale for its therapeutic drug monitoring. In fact, a target plasma concentration of sunitinib plus its active metabolite, N-desethyl sunitinib, ≥50 ng/mL was suggested. In order to quantify sunitinib and N-desethyl sunitinib in patients' plasma, we developed and validated a new LC-MS/MS method applicable to clinical routine. In solution, sunitinib and N-desethyl sunitinib undergo to photo-isomerization and many published methods overcome this problem by conducting the entire procedures of samples collection and handling under strictly light-protection. Our method is based on a simple and fast procedure that quantitatively reconverts the E-isomer of both analytes, obtained during sample draw and processing without light-protection, into their Z-forms. Moreover, our method uses a small plasma volume (30 μL) and the analytes are extracted by a rapid protein precipitation. It was validated according to EMA-FDA guidelines. The calibration curves resulted linear (R² always >0.993) over the concentration ranges (0.1-500 ng/mL for sunitinib, 0.1-250 ng/mL for N-desethyl sunitinib) with a good precision (within 7.7 % for sunitinib and 10.8% for N- desethyl sunitinib) and accuracy (range 95.8-102.9% for sunitinib and 92.3-106.2% for N-desethyl sunitinib). This method was applied to a pharmacokinetic study in one patient treated with sunitinib. Moreover, as incurred samples reanalysis is an established part of the bioanalytical process to support clinical studies, its assessment was performed early in order to assure that any reproducibility issues was detected as soon as possible. The percentage difference between the two runs resulted within ±20% in all the re-analysed samples for both sunitinib and N- desethyl sunitinib.

Targeting Angiogenesis in Pancreatic Neuroendocrine Tumors: Resistance Mechanisms

Despite being infrequent tumors, the incidence and prevalence of pancreatic neuroendocrine tumors (P-NETs) has been rising over the past few decades. In recent years, rigorous phase III clinical trials have been conducted, allowing the approval of several drugs that have become the standard of care in these patients. Although various treatments are used in clinical practice, including somatostatin analogues (SSAs), biological therapies like sunitinib or everolimus, peptide receptor radionuclide therapy (PRRT) or even chemotherapy, a consensus regarding the optimal sequence of treatment has not yet been reached. Notwithstanding, sunitinib is largely used in these patients after the promising results shown in SUN111 phase III clinical trial. However, both prompt progression as well as tumor recurrence after initial response have been reported, suggesting the existence of primary and acquired resistances to this antiangiogenic drug. In this review, we aim to summarize the most relevant mechanisms of angiogenesis resistance that are key contributors of tumor progression and dissemination. Furthermore, several targeted molecules acting selectively against these pathways have shown promising results in preclinical models, and preliminary results from ongoing clinical trials are awaited.

Impaired clearance of sunitinib leads to metabolic disorders and hepatotoxicity

BACKGROUND AND PURPOSE

Sunitinib is a small-molecule TK inhibitor associated with hepatotoxicity. The mechanisms of its toxicity are still unclear.

EXPERIMENTAL APPROACH

In the present study, mice were treated with 60, 150, and 450 mg·kg-1 sunitinib to evaluate sunitinib hepatotoxicity. Sunitinib metabolites and endogenous metabolites in liver, serum, faeces, and urine were analysed using ultra-performance LC electrospray ionization quadrupole time-of-flight MS-based metabolomics.

KEY RESULTS

Four reactive metabolites and impaired clearance of sunitinib in liver played a dominant role in sunitinib-induced hepatotoxicity. Using a non-targeted metabolomics approach, various metabolic pathways, including mitochondrial fatty acid β-oxidation (β-FAO), bile acids, lipids, amino acids, nucleotides, and tricarboxylic acid cycle intermediates, were disrupted after sunitinib treatment.

CONCLUSIONS AND IMPLICATIONS

These studies identified significant alterations in mitochondrial β-FAO and bile acid homeostasis. Activation of PPARα and inhibition of xenobiotic metabolism may be of value in attenuating sunitinib hepatotoxicity.

Clinical Efficacy and Complication Rate of Sunitinib 2/1 Versus 4/2 Schedule for the Treatment of Metastatic Renal Cell Cancer: A Systematic Review and Meta-Analysis

The treatment of renal cell carcinoma has achieved certain curative effects with the innovation of clinical drugs, such as sunitinib. However, the clinical efficacy and complication rate of the sunitinib 2/1 and 4/2 schedule in metastatic renal cell cancer remain unclear. In this study we aimed to resolve this issue by using meta-analysis to provide more theoretical guidance for clinical use. Several outcome measurements were included in this study to compare the 2 schedules such as complete response, partial response, stable disease, progressive disease, progression-free survival, overall survival, and complications. In the contrast analysis, the sunitinib 2/1 and 4/2 schedule resulted in significant improvements in prognosis. However, the sunitinib 2/1 schedule was superior to the 4/2 schedule in terms of controlling stable disease and causing fewer complications.

[Toward Personalized Cancer Therapy with Oral Molecular-targeted Agents]

Oral molecular-targeted agents are used clinically for the treatment of various types of cancer. However, even when treatment is started at the dosage indicated in the medical package insert, we have experienced many cases in which treatment had to be stopped early owing to the occurrence of serious side effects or an insufficient therapeutic effect. In recent years, a wide range of studies has been conducted on the therapeutic drug monitoring (TDM) of oral molecular-targeted therapeutic agents to prevent serious side effects and maximize the therapeutic effect. In Japan, the TDM of imatinib has been covered by insurance since 2012, and the TDM of sunitinib has been covered since 2018. In contrast, tyrosine kinase inhibitors may have severe side effects, but their TDM is not covered by medical insurance. We aimed to identify a safe, highly effective chemotherapy regimen based on scientific evidence gathered from Japanese patients. We examined the relationship between the plasma concentration of drugs and clinical findings, such as side effects and treatment effects, at our hospital. In this symposium review, we introduce our results based on the treatment of patients with renal cell carcinoma.

EGF and IGF1 affect sunitinib activity in BP-NEN: new putative targets beyond VEGFR?

Broncho-pulmonary neuroendocrine neoplasms (BP-NENs) are neoplasms orphan of an efficient therapy. Available medical treatments derived from clinical trials are not specific for the management of this malignancy. Sunitinib is a multi-receptor tyrosine-kinases (RTKs) inhibitor that has already shown its efficacy in NENs, but there are no available data about its action in BP-NENs. Therefore, our aim was to understand the effects of RTKs inhibition promoted by sunitinib in order to evaluate new putative targets useful in malignancy treatment. Since our results underlined a role for EGFR and IGF1R in modulating sunitinib antiproliferative action, we investigated the effects of erlotinib, an EGFR inhibitor, and linsitinib, an IGF1R inhibitor, in order to understand their function in regulating cells behaviour. Cell viability and caspase activation were evaluated on two immortalised human BP-NEN cell lines and primary cultures. Our results showed that after treatment with sunitinib and/or IGF1, EGF and VEGF, the antiproliferative effect of sunitinib was counteracted by EGF and IGF1 but not by VEGF. Therefore, we evaluated with AlphaScreen technology the phosphorylated EGFR and IGF1R levels in primary cultures treated with sunitinib and/or EGF and IGF1. Results showed a decrease of p-IGF1R after treatment with sunitinib and an increase after co-treatment with IGF1. Then, we assessed cell viability and caspase activation on BP-NEN cell lines after treatment with linsitinib and/or erlotinib. Results demonstrate that these two agents have a stronger antiproliferative effect compared to sunitinib. In conclusion, our results suggest that IGF1R and EGF1R could represent putative molecular targets in BP-NENs treatment.

Randomized trials and endpoints in advanced HCC: Role of PFS as a surrogate of survival

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality worldwide. Around half of patients with HCC will receive systemic therapies during their life span. The pivotal positive sorafenib trial and regulatory approval in 2007 was followed by a decade of negative studies with drugs leading to marginal antitumoral efficacy, toxicity, or trials with a lack of enrichment strategies. This trend has changed over the last 2 years with several compounds, such as lenvatinib (in first-line) and regorafenib, cabozantinib, ramucirumab and nivolumab (in second-line), showing clinical benefit. These successes came at a cost of increasing the complexity of decision-making, and ultimately, impacting the design of future clinical trials. Nowadays, life expectancy with single active agents has surpassed the threshold of 1 year and sequential strategies have provided encouraging outcomes. Overall survival (OS) remains the main endpoint in phase III investigations, but as in other solid tumours, there is a clear need to define surrogate endpoints that both reliably recapitulate survival benefits and can be assessed before additional efficacious drugs are administered. A thorough analysis of 21 phase III trials published in advanced HCC demonstrated a moderate correlation between progression-free survival (PFS) or time to progression (TTP) and OS (R = 0.84 and R = 0.83, respectively). Nonetheless, the significant differences in PFS identified in 7 phase III studies only correlated with differences in OS in 3 cases. In these cases, the hazard ratio (HR) for PFS was ≤0.6. Thus, this threshold is herein proposed as a potential surrogate endpoint of OS in advanced HCC. Conversely, PFS with an HR between 0.6-0.7, despite significance, was not associated with better survival, and thus these magnitudes are considered uncertain surrogates. In the current review, we discuss the reasons for positive or negative phase III trials in advanced HCC, and the strengths and limitations of surrogate endpoints (PFS, TTP and objective response rate [ORR]) to predict survival.

The Alternative 2/1 Schedule of Sunitinib is Superior to the Traditional 4/2 Schedule in Patients With Metastatic Renal Cell Carcinoma: A Meta-analysis

Alternate sunitinib schedules attracted the interest of oncologists recently owing to their superior safety profile. This meta-analysis compared the tolerability and efficacy of a new alternative dosing schedule (2 weeks on/1 week off) of sunitinib with the traditional 4/2 schedule in patients with metastatic renal cell carcinoma (mRCC). Studies were retrieved from Medline, Cochrane Central, Scopus, Embase, and Web of Science databases. Data were extracted and pooled as hazard ratio (HR: survival data) or odds ratio (OR: dichotomous data) using Comprehensive Meta-analysis software. Based on data of 1173 patients, the progression-free survival (HR, 0.52; 95% confidence interval [CI], 0.39-0.95; P < .0001), overall survival (HR, 0.6; 95% CI, 0.43-0.85; P < .0001), and stable disease rates (OR, 0.38; 95% CI, 0.19-0.76; P = .006) were significantly improved on the alternative 2/1 schedule, compared with the traditional 4/2 schedule. However, the complete response (OR, 1.32; 95% CI, 0.34-5.22; P = .69) and partial response (OR, 1.34; 95% CI, 0.44-4.14; P = .61) rates were comparable between the 2 regimens. The tolerability of the alternative 2/1 schedule was superior to the traditional one as investigated adverse events like fatigue (OR, 2.91; 95% CI, 1.89-4.46; P < .0001), hypertension (OR, 2.08; 95% CI, 1.56-2.75; P < .0001), and diarrhea (OR, 2.18; 95% CI, 1.19-3.98; P = .012) were significantly less common. In conclusion, the alternative 2/1 sunitinib schedule provides improved tolerability and survival in patients with mRCC. Large randomized trials with long follow-up periods are required to validate and confirm these findings.

Efficacy, Safety, and Potential Biomarkers of Sunitinib and Transarterial Chemoembolization (TACE) Combination in Advanced Hepatocellular Carcinoma (HCC): Phase II Trial

OBJECTIVES

To evaluate the safety/efficacy and explore biomarkers for a rationally designed combination of sunitinib and transarterial chemoembolization (TACE) in a prospective phase 2 study of advanced hepatocellular carcinoma (HCC).

METHODS

Inoperable HCC patients with Child-Pugh A disease received 37.5 mg sunitinib from days 1 to 7 followed by TACE on day 8. Sunitinib was resumed from days 15 to 36 followed by 2 weeks off. Patients received subsequent sunitinib cycles of 4 weeks on and 2 weeks off. Dynamic contrast-enhanced magnetic resonance imaging and circulating soluble biomarkers were assessed at baseline, day 8, day 10, and day 36.

RESULTS

Sixteen patients with liver only (n=10) and extrahepatic disease (n=6) were enrolled. After a median follow-up of 12.8 months, 2 partial responses, 11 stable disease, and 3 clinical deteriorations were seen for a clinical benefit rate of 81%. Median progression-free survival (PFS) was 8 months (95% CI, 4.3-9.3) and overall survival was 14.9 months (95% CI, 6.3-27.1). Eleven of 16 patients (69%) had grade 3/4 toxicities attributable to sunitinib, the most frequent being thrombocytopenia, amylase/lipase elevations, lymphopenia, and fatigue. Mean K (volume transfer constant) and viable tumor percent in consented patients decreased by 27% and 14.8%, respectively, with combination therapy. Soluble vascular endothelial growth factor receptor-2 (sVEGFR2) levels, cytokines (interleukin-8, interleukin-21), and monocytes decreased with combination therapy. Estimated sunitinib IC50 values of 15 and 10 ng/mL modulated K and AUC90. sVEGFR2 levels decreased with K and AUC90.

CONCLUSIONS

Encouraging progression-free survival and overall survival were seen with acceptable toxicity in our study of sunitinib and TACE combination in advanced HCC. Potential imaging and serum biomarkers showed increased benefit with combination therapy.

Targeting Tyrosine kinases in Renal Cell Carcinoma: "New Bullets against Old Guys"

Clear cell renal cell carcinoma (ccRCC) is the seventh most frequently diagnosed tumor in adults in Europe and represents approximately 2.5% of cancer deaths. The molecular biology underlying renal cell carcinoma (RCC) development and progression has been a key milestone in the management of this type of tumor. The discovery of Von Hippel Lindau (VHL) gene alterations that arouse in 50% of ccRCC patients, leads the identification of an intracellular accumulation of HIF and, consequently an increase of VEGFR expression. This change in cell biology represents a new paradigm in the treatment of metastatic renal cancer by targeting angiogenesis. Currently, there are multiple therapeutic drugs available for advanced disease, including therapies against VEGFR with successful results in patients´ survival. Other tyrosine kinases' pathways, including PDGFR, Axl or MET have emerged as key signaling pathways involved in RCC biology. Indeed, promising new drugs targeting those tyrosine kinases have exhibited outstanding efficacy. In this review we aim to present an overview of the central role of these tyrosine kinases' activities in relevant biological processes for kidney cancer and their usefulness in RCC targeted therapy development. In the immunotherapy era, angiogenesis is still an "old guy" that the medical community is trying to fight using "new bullets".

Sunitinib in patients with pancreatic neuroendocrine tumors: update of safety data

Aim: To describe the long-term safety of sunitinib in patients with progressive, well-differentiated, advanced/metastatic pancreatic neuroendocrine tumors. Patients & methods: Sunitinib- and placebo-treated patients from the Phase III study continued to receive sunitinib (37.5 mg on a continuous daily-dosing regimen) in two open-label extension studies. Results: Median (range) treatment exposure: 30.2 (0.7–269.4) and 87.1 (3.9–319.4) weeks for medium-term (n = 41) and long-term-treated (n = 61) populations, respectively. All patients experienced ≥1 adverse event (AE); 47 (45.6%) reported serious AEs. Common all-causality AEs: diarrhea (63.1%); neutropenia (43.7%); abdominal pain (40.8%). Fifteen (14.6%) patients discontinued treatment due to treatment-related AEs. Conclusion: The safety of extended sunitinib treatment was consistent with the known safety profile of sunitinib in pancreatic neuroendocrine tumors.

The Current and Evolving Landscape of First-Line Treatments for Advanced Renal Cell Carcinoma

Agents targeting the vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), as well as the mammalian target of rapamycin (mTOR) and immune checkpoint receptor programmed death 1 (PD-1) signaling pathway have improved clinical outcomes for patients with advanced renal cell carcinoma (RCC). The VEGFR tyrosine kinase inhibitors (TKIs) pazopanib and sunitinib are FDA-approved first-line treatment options for advanced RCC; however, other treatment options in this setting are available, including the recently approved combination of nivolumab (anti-PD-1) and ipilimumab (anti-cytotoxic T-lymphocyte-associated protein-4 [CTLA-4]) for patients with intermediate or poor risk. Unfortunately, treatment guideline recommendations provide little guidance to aid first-line treatment choice. In addition, several ongoing randomized phase III trials of investigational first-line regimens may complicate the RCC treatment paradigm if these agents gain approval. This article reviews clinical trial and real-world evidence for currently approved and investigational first-line treatment regimens for advanced RCC and provides clinical evidence to aid first-line treatment selection. IMPLICATIONS FOR PRACTICE: Vascular endothelial growth factor receptor tyrosine kinase inhibitors are approved by the U.S. Food and Drug Administration as first-line treatment options for advanced renal cell carcinoma; however, the treatment paradigm is rapidly evolving. The combination of nivolumab plus ipilimumab was recently approved for intermediate- and poor-risk patients, and other combination strategies and novel first-line agents will likely be introduced soon.

Investigational multitargeted kinase inhibitors in development for head and neck neoplasms

INTRODUCTION

Despite advances in treatment, head and neck squamous cell carcinoma (HNSCC) survival rates remain stagnant. Current treatment is associated with significant toxicities and includes chemotherapy, radiation, surgery, and few targeted treatments. Targeted treatments, epidermal growth factor receptor (EGFR)-targeted agent, cetuximab, and immune checkpoint inhibitors, pembrolizumab and nivolumab, show improved toxicity profiles and modestly improved survival in select patients. An urgent need remains to identify novel targeted treatments for single-agent or combined therapy use.

AREAS COVERED

Multitargeted kinase inhibitors are small molecule inhibitors with limited toxicity. This review will focus on early-stage investigations of multitargeted tyrosine kinase inhibitors (m-TKIs) (those that target at least two tyrosine kinases) for HNSCC. Preclinical and early trials investigating m-TKIs for various disease settings of HNSCC will be evaluated for efficacy, identification of significant biomarkers and potential for combination therapy.

EXPERT OPINION

Few single agent m-TKIs have demonstrated efficacy in unselected HNSCC populations. The most promising clinical results have been obtained when m-TKIs are tested in combination with other therapies, including immunotherapy, or in mutation-defined subgroups of patients. The future success of m-TKIs will rely on identification, in preclinical models and clinical trials, of predictive biomarkers of response and mechanisms of innate and acquired resistance.

An Update on Drug-Induced Pigmentation

Drug-induced pigmentation accounts for up to 20% of all cases of acquired pigmentation. A thorough review of medical history and previous and ongoing medications as well as a complete skin examination can guide diagnosis. Implicated agents include alkylating/cytotoxic agents, analgesics, antiarrhythmics, anticoagulants, antiepileptics, antimalarials, antimicrobials, antiretrovirals, metals, prostaglandin analogs, and psychotropic agents, among others. Confirming true drug associations can be challenging, especially in the setting of delayed onset of pigmentation and coexisting polypharmacy.

Long-term survival outcome with tyrosine kinase inhibitors and surgical intervention in patients with metastatic or recurrent gastrointestinal stromal tumors: A 14-year, single-center experience

The long‐term effects of tyrosine kinase inhibitors (TKIs), including imatinib, and surgical intervention on advanced gastrointestinal stromal tumor (GIST) were evaluated. All 379 patients had metastatic or recurrent GIST and started 400 mg/d imatinib at the Asan Medical Center in periods 1 and 2 [2001‐2007 (33.2%) and 2008‐2014 (66.8%), respectively]. Men constituted 60.4%; median patient age and tumor size at the initiation of imatinib were 58.6 (14.6‐85.5) years and 51 (0‐324) mm, respectively, without differences between periods except for older age and less preimatinib surgery in period 2. Response and disease control rates with imatinib in measurable GIST were 63.1% and 94.3%, respectively, without differences between periods. More patients in period 2 underwent surgical resection for TKI‐responsive diseases within the first 2 years (24.9%, P = 0.006). With a median follow‐up of 6.1 years (2.5‐16.0) in survivors, median progression‐free survival (PFS) was 5.4 years [95% confidence interval (CI), 4.0‐6.9]. Subsequent sunitinib (P = 0.066) and regorafenib (P = 0.003) were more commonly administered in period 2. Median overall survival (OS) was 8.8 years (95% CI, 7.8‐9.7). PFS with imatinib (P = 0.002) and OS (P = 0.019) were significantly longer in period 2. Young age, smaller tumor size at the initiation of imatinib, KIT exon 11 mutation, surgical intervention, and period 2 were favorable factors for PFS and OS. Patients with advanced GIST showed better prognosis with the optimal use of imatinib, along with active surgical intervention and more common use of subsequent TKIs in period 2.

Survival Prolongation Index as a Novel Metric to Assess Anti-Tumor Activity in Xenograft Models

A single efficacy metric quantifying anti-tumor activity in xenograft models is useful in evaluating different tumors' drug sensitivity and dose-response of an anti-tumor agent. Commonly used metrics include the ratio of tumor volume in treated vs. control mice (T/C), tumor growth inhibition (TGI), ratio of area under the curve (AUC), and growth rate inhibition (GRI). However, these metrics have some limitations. In particular, for biologics with long half-lives, tumor volume (TV) of treated xenografts displays a delay in volume reduction (and in some cases, complete regression) followed by a growth rebound. These observed data cannot be described by exponential functions, which is the underlying assumption of TGI and GRI, and the fit depends on how long the tumor volumes are monitored. On the other hand, T/C and TGI only utilizes information from one chosen time point. Here, we propose a new metric called Survival Prolongation Index (SPI), calculated as the time for drug-treated TV to reach a certain size (e.g., 600 mm³) divided by the time for control TV to reach 600mm³ and therefore not dependent on the chosen final time point t_f. Simulations were conducted under different scenarios (i.e., exponential vs. saturable growth, linear vs. nonlinear kill function). For all cases, SPI is the most linear and growth-rate independent metric. Subsequently, a literature analysis was conducted using 11 drugs to evaluate the correlation between pre-clinically obtained SPI and clinical overall response. This retrospective analysis of approved drugs suggests that a predicted SPI of 2 is necessary for clinical response.

Phase I Dose-Escalation Study of Once Weekly or Once Every Two Weeks Administration of High-Dose Sunitinib in Patients With Refractory Solid Tumors

PURPOSE

Dose and schedule optimization of treatment with tyrosine kinase inhibitors is of utmost importance. On the basis of preclinical data, a phase I clinical trial of once weekly or once every 2 weeks administration of high-dose sunitinib in patients with refractory solid malignancies was conducted.

PATIENTS AND METHODS

Patients with advanced cancer refractory to standard treatment were eligible. With use of a standard 3 + 3 phase I design, patients received escalating doses of sunitinib, in 100 mg increments, starting at 200 mg once weekly. In both the once weekly and once every 2 weeks cohorts, 10 more patients were included at the maximum tolerated dose level. Primary end points were safety and tolerability.

RESULTS

Sixty-nine patients with advanced cancer, predominantly colorectal cancer (42%), were treated with this alternative dosing regimen. Maximum tolerated dose was established at 300 mg once weekly and 700 mg once every 2 weeks, resulting in nine- and 18-fold higher maximum plasma concentrations compared with standard dose, respectively. Treatment was well tolerated, with fatigue (81%), nausea (48%), and anorexia (33%) being the most frequent adverse events. The only grade 3 or 4 treatment-related adverse event in 5% or more of patients was fatigue (6%). Sixty-three percent of patients had significant clinical benefit, with a 30% progression-free survival of 5 months or more.

CONCLUSION

Sunitinib administered once weekly at 300 mg or once every 2 weeks at 700 mg is feasible, with comparable tolerability as daily administration. Administration of 700 mg once every 2 weeks can be considered as the most optimal schedule because of the highest maximum plasma concentration being reached. The promising preliminary antitumor activity of this alternative schedule in heavily pretreated patients warrants further clinical evaluation and might ultimately indicate a class characteristic of tyrosine kinase inhibitors.

Phase I, First-in-Human, Dose-Escalation Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Vorolanib in Patients with Advanced Solid Tumors

Lessons Learned.

Pharmacokinetic results underscore that the vorolanib (X‐82) study design was successful without the need for further dose escalation beyond 400 mg once daily (q.d.).

Therefore, the recommended dose of X‐82 as a single agent in patients with advanced cancer is 400 mg q.d.

Background.

Vorolanib (X‐82) is a novel, oral, multikinase vascular endothelial growth factor (VEGF) receptor/platelet‐derived growth factor (PDGF) receptor inhibitor that was developed on the same chemical scaffold as sunitinib, but designed to improve upon the safety profile while maintaining the efficacy of sunitinib. By targeting the VEGF and PDGF receptors, X‐82 was expected to disrupt tumor angiogenesis and be active in a broad spectrum of solid tumors. Therefore, we determined the maximum tolerated dose (MTD) and characterized the preliminary pharmacokinetics and clinical tumor response of X‐82 as a single agent in patients with advanced solid tumors.

Methods.

Adult patients with advanced solid tumors received X‐82 as tablets or capsules (once daily [q.d.] or b.i.d.) every 4 weeks. Patients were evaluated for response every 8 weeks, and continued treatment until disease progression or intolerable toxicity.

Results.

Fifty‐two patients received study treatment in 17 cohorts. X‐82 capsule dosing was as follows: cohorts 1–6 (20–400 mg q.d.) and cohorts 7–8 (140–200 mg b.i.d.). Patients in cohorts 9–17 received 50–800 mg q.d. tablet dosing. The median time on treatment was 58 days. X‐82 blood pharmacokinetics appeared dose‐independent with a t_1/2 of 5.13 hours and 6.48 hours for capsule and tablet formulations, respectively. No apparent accumulation was observed after 21 days of daily dosing.

Conclusion.

X‐82 had a safety profile consistent with its mechanism of action. It has a short half‐life and was well tolerated by most patients. Study enrollment ended prior to the determination of the MTD because of the apparent saturation of absorption at 400–800 mg. The recommended dose of X‐82 as a single agent in patients with advanced cancer is 400 mg q.d.

Improved Long-Term Clinical Outcomes And Safety Profile Of Sunitinib Dosing Schedule With 4/2 Switched To 2/1 In Patients With Metastatic Renal Cell Carcinoma

Purpose: This study aimed to identify the survival benefit and safety of alternative dosage schedules for sunitinib in metastatic renal cell carcinoma.

Materials and Methods: Clinicopathologic and survival data of patients treated with sunitinib as first-line therapy were retrospectively reviewed. Patients were classified into three groups: a standard dosing schedule (4/2 schedule), alternative dosing schedule (2/1 schedule), and switched dosing schedule (4/2-2/1 schedule).

Results: Ninety-nine patients were retrospectively included. Seventy-five (75.8%) patients were initially administrated with a 4/2 schedule of sunitinib, while 24 were started with the 2/1 schedule. During treatment, 45 (60.0%) patients with an initial 4/2 schedule switched to a 2/1 schedule (4/2-2/1 schedule) due to severe adverse events (AEs) or poor tolerance. Compared to that with a 4/2 schedule, patients with a 2/1 schedule had a much lower incidence of grade 3/4 AEs (69.6% vs. 40.6%, p=0.001). Overall, the 4/2-2/1 schedule was associated with the best survival benefits. Among the 4/2, 2/1, and 4/2-2/1 schedule groups, the median PFS was 12.5, 11.0, and 25.0 months, respectively (p=0.003), and the median OS was 21.0, 28.0, and 52.0 months, respectively (p=0.03). Multivariate analysis identified the 4/2-2/1 schedule as an independent factor predicting favorable PFS. Although without statistical significance, 4/2-2/1 schedule could decrease 55% risk of death. Furthermore, patients with unfavorable IMDC risk seemed to have more opportunity to achieve better survival from the 4/2-2/1 dosing schedule.

Conclusion: Patients with a 4/2-2/1 schedule could minimize treatment-related toxicities; more importantly, patients with 4/2-2/1 schedule could achieve a superior survival benefit.