Clinical implications of pharmacokinetics of sunitinib malate and N-desethyl-sunitinib plasma concentrations for treatment outcome in metastatic renal cell carcinoma patients

Effect of isavuconazole on the pharmacokinetics of sunitinib and its mechanism

BACKGROUND

Sunitinib, a newly developed multi-targeted tyrosine kinase inhibitor (TKI), has become a common therapeutic option for managing advanced renal cell carcinoma (RCC). Examining the mechanism underlying the interaction between sunitinib and isavuconazole was the aim of this effort.

METHODS

The concentrations of sunitinib and its primary metabolite, N-desethyl sunitinib, were analyzed and quantified using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Our study evaluated the potential interaction between isavuconazole and sunitinib using rat liver microsomes (RLM), human liver microsomes (HLM), and in vivo rat models. For the in vivo study, two groups (n = 5) of Sprague-Dawley (SD) rats were randomly allocated to receive sunitinib either with or without co-administration of isavuconazole. Additionally, the effects of isavuconazole on the metabolic stability of sunitinib and N-desethyl sunitinib were studied in RLM in vitro.

RESULTS

Our findings demonstrated that in RLM, isavuconazole exhibited a mixed non-competitive and competitive inhibition mechanism, with an IC50 (half maximal inhibitory concentration) value of 1.33 µM. Meanwhile, in HLM, isavuconazole demonstrated a competitive inhibition mechanism, with an IC50 of 5.30 µM. In vivo studies showed that the presence of isavuconazole significantly increased the pharmacokinetic characteristics of sunitinib, with the AUC(0→t), AUC(0→∞), and Tmax rising to approximately 211.38%, 203.92%, and 288.89%, respectively, in contrast to the control group (5 mg/kg sunitinib alone). The pharmacokinetic characteristics of the metabolite N-desethyl sunitinib in the presence of isavuconazole remained largely unchanged compared to the control group. Furthermore, in vitro metabolic stability experiments revealed that isavuconazole inhibited the metabolic processing of both sunitinib and N-desethyl sunitinib.

CONCLUSIONS

Isavuconazole had a major impact on sunitinib metabolism, providing fundamental information for the precise therapeutic administration of sunitinib.

The CYP3A inducer dexamethasone affects the pharmacokinetics of sunitinib by accelerating its metabolism in rats

Sunitinib, a novel anti-tumor small molecule targeting VEGFR, is prescribed for advanced RCC and GISTs. Sunitinib is primarily metabolized by the CYP3A enzyme. It is well-known that dexamethasone serves as a potent inducer of this enzyme system. Nonetheless, the effect of dexamethasone on sunitinib metabolism remains unclear. This study examined the effect of dexamethasone on the pharmacokinetics of sunitinib and its metabolite N-desethyl sunitinib in rats. The plasma levels of both compounds were measured using UHPLC-MS/MS. Pharmacokinetic parameters and metabolite ratio values were calculated. Compare to control group, the low-dose dexamethasone group and high-dose dexamethasone group decreased the AUC(0-t) values of sunitinib by 47 % and 45 %, respectively. Meanwhile, the AUC(0-t) values of N-desethyl sunitinib were increased by 2.2-fold and 2.4-fold in low-dose dexamethasone group and high-dose dexamethasone group, respectively. The CL values for sunitinib were both approximately 45 % higher in the two dexamethasone groups. Remarkably, metabolite ratio values increased over 5-fold in both low-dose dexamethasone group and high-dose dexamethasone group, indicating a significant enhancement of sunitinib metabolism by dexamethasone. Moreover, the total levels of sunitinib and its metabolite are also significantly increased. The impact of interactions on sunitinib metabolism, as observed with CYP3A inducers such as dexamethasone, is a crucial consideration for clinical practice. To optimize the dosage and prevent adverse drug events, therapeutic drug monitoring can be employed to avoid the toxicity from such interactions.

A Randomized, Double-Blind, Placebo-Controlled Trial Evaluating the Effect of Topical Urea for Secondary Prophylaxis of Hand Foot Skin Reaction in Renal Cell Cancer Patients on Sunitinib Therapy

INTRODUCTION

Hand foot skin reaction (HFSR) is a common dose-limiting adverse effect of multi kinase inhibitors (MKI) whose mechanism is not fully understood, and the prophylaxis is inadequate.

OBJECTIVE

In this pilot study, a double-blind, randomized placebo-controlled trial was conducted to evaluate the effect of topical urea in secondary prevention of sunitinib-induced HFSR in renal cell cancer patients.

METHODS

Out of 55 screened patients, 14 were randomized to receive topical urea or placebo for four weeks. The association of HFSR with drug levels of sunitinib and its metabolite (n-desethyl sunitinib), genetic polymorphism of VEGFR2 gene, quality of life (QOL) and biochemical markers was also assessed.

RESULTS

The results showed that urea-based cream was not superior to placebo (P = .075). There was no change in the QOL in both the groups. Single nucleotide polymorphism was checked for two nucleotides rs1870377 and rs2305948 located in VEGFR2 gene on chromosome 4. SNP (variant T > A) at rs1870377 was associated with appearance of new HFSR as compared to the wild type, although the association was not statistically significant (OR 0.714). There was no statistically significant difference between mean plasma levels of sunitinib and N-desethyl sunitinib in urea arm as compared to placebo arm as compared to placebo. The best fit population pharmacokinetic model for sunitinib was one compartment model with first order absorption and linear elimination. The median (IQR) of population parameters calculated from the population pharmacokinetics model for Ka, V and Cl was 0.22 (0.21-0.24) h-1, 4.4 (4.09-4.47) L, 0.049 (0.042-0.12) L/hr, respectively.

CONCLUSION

The study suggested that the urea-based cream was not superior to placebo in decreasing the appearance of new HFSR in renal cancer patients receiving 4:2 regimen of sunitinib.

Association of sunitinib concentration and clinical outcome in patients with metastatic renal cell carcinoma treated with a 2-week-on and 1-week-off schedule

WHAT IS KNOWN AND OBJECTIVE

Sunitinib is used as a first-line therapy for metastatic renal cell carcinoma. The primary aim of this study was to determine the optimal total sunitinib (sunitinib plus N-desethyl sunitinib) trough concentration for the alternative dosing schedule: 2-week-on and 1-week-off schedule (2/1 schedule).

METHODS

Patients with metastatic renal cell carcinoma treated with the 2/1 schedule of sunitinib, whose total sunitinib concentrations were available, were recruited for this study. Out of 19 patients, 17 whose sunitinib dosage was not changed until the measurement of drug concentration were eligible for the analysis of the relationship between total sunitinib concentration and clinical outcome. Individual pharmacokinetic parameters in 19 patients were estimated via the Bayesian analysis.

RESULTS

The onset of severe (grade ≥3) adverse effects among 17 patients during 3 weeks as a first course of sunitinib therapy was observed in 7 (41.2%) patients. The median total sunitinib concentration in patients with severe adverse effects was significantly higher compared with that in patients without severe adverse effects [median: 119 (113-131) vs. 87.8 (77.4-102) ng/mL, p = 0.01]. According to the receiver operating characteristic analysis of the onset of severe adverse effects, the cut-off value of the total sunitinib concentration was 108 ng/mL. Patients with a total sunitinib concentration lower than 108 ng/mL had a longer time to first dose reduction or withdrawal due to adverse effects compared with those with a total sunitinib concentration of 108 ng/mL or higher (p = 0.03). The probability without treatment failure was not significantly different between the two concentration groups. In addition, the estimated sunitinib apparent oral clearance (CL/F) was significantly lower in the severe adverse effects group. Our simulation demonstrated that 0.67-time dose is needed for patients with approximately 90.0 ng/mL of sunitinib concentration on day 7 to maintain the concentration at the same level as the patients with higher CL/F.

WHAT IS NEW AND CONCLUSION

Maintaining the total sunitinib trough concentrations of less than 108 ng/mL is safe to avoid the onset of serious adverse effects without increasing the treatment failure in patients with metastatic renal cell carcinoma treated with the 2/1 schedule of sunitinib.

Efficacy and Safety of Individualized Schedule of Sunitinib by Drug Monitoring in Patients with Metastatic Renal Cell Carcinoma

Purpose

To investigate the survival benefit and safety of individualized schedules for sunitinib in patients with metastatic renal cell carcinoma (mRCC) through plasma concentration monitoring.

Methods

A total of 105 patients with mRCC were enrolled. The schedule was adjusted in two ways: therapeutic drug monitoring (TDM) and toxicity-adjusted schedule (TAS). One group of patients were without any schedule adjustment (maintained schedule, MAS). Progression-free survival (PFS), overall survival (OS), tumor response, and adverse events (AEs) were compared. The relationship between AEs and steady-state concentration or consecutive monitoring curves was explored. Further monitoring of individualized schedules was also conducted.

Results

Based on the plasma concentration, the schedules of 18 patients were adjusted in the TDM group. The schedules were adjusted in 37 patients due to severe AEs in the TAS group, while 50 patients were without any schedule adjustment. The median PFS and OS were better in the TDM group than the other two groups (p = 0.001 and p = 0.004, respectively). Univariate and multivariate analyses indicated that TDM could decrease the risk of death independently (p = 0.026). Moreover, the incidence of grades 3/4 AEs decreased from 88.9% to 33.3% in the TDM group (p = 0.001). Sunitinib concentration in 150–200ng/mL was regarded as a “transitional zone” due to severe AEs mainly happened when concentration elevated over it. After TDM, further plasma concentration monitoring indicated that individualized schedules enabled sunitinib concentration to fluctuate in a much safer range.

Conclusion

Treatment-related toxicities could be minimized through plasma concentration monitoring. Patients with adjusted schedules by therapeutic drug monitoring could achieve better survival benefits.

Outcomes of axitinib versus sunitinib as first-line therapy to patients with metastatic renal cell carcinoma in the immune-oncology era

Although combination immune checkpoint inhibitor (immuno‐oncology [IO]) therapy is the first‐line treatment for metastatic renal cell carcinoma (mRCC), it mostly causes resistance and tumor regrowth. Therefore, an optimal second‐line therapy is necessary. Such therapy typically comprises vascular endothelial growth factor receptor‐tyrosine kinase inhibitors (VEGFR‐TKIs). This study was aimed at comparing the efficacy of two TKIs—axitinib and sunitinib—in mRCC patients. From January 2008 to October 2018, we registered 703 mRCC patients from 8 Japanese institutes. Of these, 408 patients received axitinib or sunitinib as the first‐line treatment. Thereafter, efficacy and survival rate were compared between the axitinib and sunitinib groups. To reduce the effects of selection bias and potential confounders, propensity score matching analysis was performed. Axitinib and sunitinib were administered in 274 and 134 patients, respectively. More than 25% of the patients received nivolumab sequence therapy. To calculate the propensity scores for each patient, we performed multivariate logistic regression analysis. The objective response rate, progression‐free survival (PFS), cause‐specific survival, and overall survival (OS) were significantly better in the axitinib group than in the sunitinib group. Furthermore, the OS was better in the nivolumab‐treated patients in the axitinib group. Axitinib showed higher efficacy and afforded greater survival benefits than did sunitinib when administered as first‐line therapy in mRCC patients. Thus, from among VEGFR‐TKIs, axitinib might be a possible option for application in the middle of IO drug‐based treatment sequences.

Tyrosine Kinase Inhibitor Sunitinib Delays Platelet-Induced Coagulation: Additive Effects of Aspirin

BACKGROUND

 Sunitinib is a multitarget tyrosine kinase inhibitor (TKI) used for cancer treatment. In platelets, sunitinib affects collagen-induced activation under noncoagulating conditions. We investigated (1) the effects of sunitinib on thrombus formation induced by other TK-dependent receptors, and (2) the effects under coagulating conditions. Cardiovascular disease is a comorbidity in cancer patients, resulting in possible aspirin treatment. Sunitinib and aspirin are associated with increased bleeding risk, and therefore we also investigated (3) the synergistic effects of these compounds on thrombus and fibrin formation.

METHODS

 Blood or isolated platelets from healthy volunteers or cancer patients were incubated with sunitinib and/or aspirin or vehicle. Platelet activation was determined by TK phosphorylation, flow cytometry, changes in [Ca²⁺]_i, aggregometry, and whole blood perfusion over multiple surfaces, including collagen with(out) tissue factor (TF) was performed.

RESULTS

 Sunitinib reduced thrombus formation and phosphatidylserine (PS) exposure under flow on collagen type I and III. Also, sunitinib inhibited glycoprotein VI-induced TK phosphorylation and Ca²⁺ elevation. Upon TF-triggered coagulation, sunitinib decreased PS exposure and fibrin formation. In blood from cancer patients more pronounced effects of sunitinib were observed in lung and pancreatic as compared to neuroglioblastoma and other cancer types. Compared to sunitinib alone, sunitinib plus aspirin further reduced platelet aggregation, thrombus formation, and PS exposure on collagen under flow with(out) coagulation.

CONCLUSION

 Sunitinib suppresses collagen-induced procoagulant activity and delays fibrin formation, which was aggravated by aspirin. Therefore, we urge for awareness of the combined antiplatelet effects of TKIs with aspirin, as this may result in increased risk of bleeding.

Ion-Complex Microcrystal Formulation Provides Sustained Delivery of a Multimodal Kinase Inhibitor from the Subconjunctival Space for Protection of Retinal Ganglion Cells

Glaucoma is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is one of the major risk factors for glaucoma onset and progression, and available pharmaceutical interventions are exclusively targeted at IOP lowering. However, degeneration of retinal ganglion cells (RGCs) may continue to progress despite extensive lowering of IOP. A complementary strategy to IOP reduction is the use of neuroprotective agents that interrupt the process of cell death by mechanisms independent of IOP. Here, we describe an ion complexation approach for formulating microcrystals containing ~50% loading of a protein kinase inhibitor, sunitinib, to enhance survival of RGCs with subconjunctival injection. A single subconjunctival injection of sunitinib-pamoate complex (SPC) microcrystals provided 20 weeks of sustained retina drug levels, leading to neuroprotection in a rat model of optic nerve injury. Furthermore, subconjunctival injection of SPC microcrystals also led to therapeutic effects in a rat model of corneal neovascularization. Importantly, therapeutically relevant retina drug concentrations were achieved with subconjunctival injection of SPC microcrystals in pigs. For a chronic disease such as glaucoma, a formulation that provides sustained therapeutic effects to complement IOP lowering therapies could provide improved disease management and promote patient quality of life.

Therapeutic Drug Monitoring of Sunitinib in Gastrointestinal Stromal Tumors and Metastatic Renal Cell Carcinoma in Adults-A Review

BACKGROUND

Sunitinib is an inhibitor of multiple receptor tyrosine kinases and is a standard-of-care treatment for advanced and metastatic renal cell carcinoma and a second-line treatment in locally advanced inoperable and metastatic gastrointestinal stromal tumors. A fixed dose of the drug, however, does not produce a uniform therapeutic outcome in all patients, and many face adverse effects and/or toxicity. One of the possible causes of the interindividual variability in the efficacy and toxicity response is the highly variable systemic exposure to sunitinib and its active metabolite. This review aims to summarize all available clinical evidence of the treatment of adult patients using sunitinib in approved indications, addressing the necessity to introduce proper and robust therapeutic drug monitoring (TDM) of sunitinib and its major metabolite, N-desethylsunitinib.

METHODS

The authors performed a systematic search of the available scientific literature using the PubMed online database. The search terms were "sunitinib" AND "therapeutic drug monitoring" OR "TDM" OR "plasma levels" OR "concentration" OR "exposure." The search yielded 520 journal articles. In total, 447 publications were excluded because they lacked sufficient relevance to the reviewed topic. The remaining 73 articles were, together with currently valid guidelines, thoroughly reviewed.

RESULTS

There is sufficient evidence confirming the concentration-efficacy and concentration-toxicity relationship in the indications of gastrointestinal stromal tumors and metastatic renal clear-cell carcinoma. For optimal therapeutic response, total (sunitinib + N-desethylsunitinib) trough levels of 50-100 ng/mL serve as a reasonable target therapeutic range. To avoid toxicity, the total trough levels should not exceed 100 ng/mL.

CONCLUSIONS

According to the current evidence presented in this review, a TDM-guided dose modification of sunitinib in selected groups of patients could provide a better treatment outcome while simultaneously preventing sunitinib toxicity.

Therapeutic Bayesian monitoring of sunitinib in two patients with impaired absorption or elimination

WHAT IS KNOWN AND OBJECTIVE

Sunitinib pharmacokinetics can be influenced by the physio-pathological conditions of individual patients. Therapeutic drug monitoring (TDM) helps to optimize efficacy and reduce the risk of adverse effects. We report on the use of Bayesian analysis to optimize sunitinib blood levels.

CASE SUMMARY

We describe two patients with risk of sunitinib pharmacokinetic variability due to gastrectomy and ongoing haemodialysis, respectively. TDM and Bayesian estimation allowed maintaining their sunitinib pharmacokinetic profiles within the usual limits.

WHAT IS NEW AND CONCLUSION

Our analysis showed that Bayesian analysis can be successfully applied for real-time TDM to optimize sunitinib blood levels in patients with major comorbidities.

Effects of CYP3A inhibitors ketoconazole, voriconazole, and itraconazole on the pharmacokinetics of sunitinib and its main metabolite in rats

Sunitinib is a small molecule inhibitor of multiple receptor tyrosine kinases such as platelet derived growth factor receptor, vascular endothelial growth factor receptor, kit receptor and other receptors. The US Food and Drug Administration (FDA) has approved sunitinib for the treatment of advanced renal cell carcinoma and gastrointestinal stromal tumors. It has been reported that sunitinib was mainly metabolized by CYP3A but its pharmacokinetic interactions have not been revealed. In this study, we investigated whether CYP3A inhibitors (ketoconazole, voriconazole, and itraconazole) could influence the pharmacokinetics of sunitinib and its equipotent metabolite N-desethyl sunitinib in a drug-drug interaction study in Sprague Dawley (SD) rats. The results showed that ketoconazole and voriconazole significantly increased the exposure of sunitinib, decreased the exposure of N-desethyl sunitinib, and inhibited the metabolism of sunitinib in rats. However, itraconazole showed only a weak effect on pharmacokinetics and metabolism. Coadministration of sunitinib with ketoconazole and voriconazole should be avoided if possible or if not, there should be therapeutic drug monitoring of the levels of sunitinib and N-desethyl sunitinib. Therefore, drug-drug interaction should be considered when sunitinib is administered in conjunction with CYP3A inhibitors, which might lead to toxicity.

First-line axitinib therapy is less effective in metastatic renal cell carcinoma with spindle histology

Axitinib, a vascular endothelial growth factor receptor-tyrosine kinase inhibitor, will be used in combination first-line therapies against metastatic renal cell carcinoma (mRCC), but its effects as a first-line monotherapy are unclear. Thus, we aimed to elucidate pretreatment clinical factors that predict the prognosis of patients with mRCC receiving first-line axitinib therapy. We enrolled 63 patients with mRCC treated with axitinib as first-line therapy between Nov. 2003 and Jul. 2018. Progression-free survival (PFS) and overall survival (OS) were assessed using the Wald χ² statistic in Cox proportional hazards regression. Median patient age was 67 (range: 25-85) years. Seven (11.1%) patients were classified as being at favorable risk, 33 (52.4%) at intermediate risk, and 23 (36.5%) at poor risk according to the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk classification system. Median follow-up duration after axitinib initiation was 14 (range: 1-72) months. Median PFS and OS were 18 months and 65 months, respectively. Cox regression analyses of clinical predictors revealed that high C-reactive protein (CRP) levels were significantly correlated with shorter PFS [hazard ratio (HR), 1.63; 95% confidence interval (CI) 1.7-4.0)], whereas spindle cells and poor IMDC risk scores were related to worse OS (HR, 2.87 and 2.88, respectively; 95% CI 1.4-11.0 and 1.1-8.5, respectively). Thus, patients with mRCC and spindle histology or poor IMDC risk scores had worse OS, and those with high CRP levels had shorter PFS in first-line axitinib treatment. Other therapies might be more suitable for initial management of such patients.

Optimizing treatment of renal cell carcinoma with VEGFR-TKIs: a comparison of clinical pharmacology and drug-drug interactions of anti-angiogenic drugs

Anti-angiogenic treatment is an important option that has changed the therapeutic landscape in various tumors, particularly in patients affected by renal cell carcinoma (RCC). Agents that block signaling pathways governing tumor angiogenesis have raised high expectations among clinicians. Vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs) comprise a heterogeneous class of drugs with distinct pharmacological profiles, including potency, selectivity, pharmacokinetics and drug-drug interactions. Among them, tivozanib is one of the last TKIs introduced in the clinical practice; this drug selectively targets VEGFRs, it is characterized by a favorable pharmacokinetics and safety profile and has been approved as first-line treatment for patients with metastatic RCC (mRCC). In this article, we describe the clinical pharmacology of selected VEGFR-TKIs used for the treatment of mRCC, highlighting the relevant differences; moreover we aim to define the main pharmacologic characteristics of these drug.

Safety and Efficacy of Bis-Glyceryl Ascorbate (Amitose DGA) to Prevent Hand-Foot Skin Reaction in Patients With Renal Cell Carcinoma Receiving Sunitinib Therapy: Protocol for a Phase I/II, Uncontrolled, Single-Arm, Open-Label Trial

Background

Hand-foot skin reaction (HFSR) is a serious side effect induced by multiple-tyrosine kinase inhibitors (TKIs). HFSR can cause treatment interruption or decreased dosing. HFSR also markedly decreases quality of life and is associated with the therapeutic efficacy of multiple-TKIs. Therefore, the management and prevention of HFSR is an important issue; however, an effective method for its prevention has not been established. Specific ascorbic acid derivatives can reverse multiple-TKI-induced keratinocyte growth and pathological changes in vitro.

Objective

This study was designed to evaluate the safety of bis-glyceryl ascorbate (Amitose DGA), a novel, hydrosoluble, and moisturizing ascorbic acid derivative, in patients with renal cell carcinoma (RCC) receiving sunitinib therapy. This study was also designed to evaluate Amitose DGA’s preventive efficacy for sunitinib-induced HFSR.

Methods

This is a Phase I/II, single-center, uncontrolled, single-arm, open-label trial. We will recruit a total of 30 patients with RCC receiving sunitinib therapy, with a 2-week-on and 1-week-off schedule. The participants will apply Amitose DGA-containing cream over both palmar and plantar surfaces within two treatment cycles (ie, 6 weeks) of sunitinib in combination with a general moisturizing agent, in addition to standard-of-care processes. Safety assessments will include dermatological abnormalities, clinical laboratory tests, and incidence of adverse events. Efficacy assessments will include development of HFSR and therapeutic outcomes associated with sunitinib.

Results

Recruitment to the study began in August 2017 and is ongoing in Japan. To date, 21 subjects have been recruited. Study completion is expected in 2021.

Conclusions

This is the first clinical study of Amitose DGA-containing cream in patients with RCC who are receiving sunitinib therapy. The single-center, single-arm, open-label design was selected to maximize subject exposure and increase the likelihood of achieving our study endpoints. The results will provide valuable and preliminary evidence of the effects of Amitose DGA-containing cream on HFSR.

Trial Registration

UMIN Clinical Trials Registry UMIN000027209; https://upload.umin.ac.jp/cgi-open-bin/ctr /ctr_view.cgi?recptno=R000031174

International Registered Report Identifier (IRRID)

DERR1-10.2196/14636