Pharmacokinetic interaction involving sorafenib and the calcium-channel blocker felodipine in a patient with hepatocellular carcinoma

Anti-Angiogenic Tyrosine Kinase Inhibitor-Related Toxicities Among Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Targeting of angiogenesis has become a major therapeutic approach for the treatment of various advanced cancers. There are many unresolved questions on the toxicity of anti-angiogenic tyrosine kinase inhibitors (TKIs).

OBJECTIVE

We performed a meta-analysis to assess the toxicity prevalence of the different anti-angiogenic TKIs among cancer patients and in subpopulations of interest including patients with renal cell carcinoma.

PATIENTS AND METHODS

We searched the MEDLINE and Cochrane Library databases to November 2023. Clinical trials were eligible if they set out to report the grade ≥3 toxicities related to one of the seven currently approved anti-angiogenic TKIs as monotherapies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was applied with PROSPERO (CRD42023411946).

RESULTS

The 421 eligible studies included a total of 56,895 cancer patients treated with anti-angiogenic TKI monotherapy. Twenty-four different cancer types were identified, mainly renal cell carcinoma (41.9% of the patients). The anti-angiogenic TKI was sorafenib (34.5% of the patients), sunitinib (30.5%), regorafenib (10.7%), pazopanib (9.4%), cabozantinib (7.7%), axitinib (4.3%), and lenvatinib (2.9%). The pooled prevalence of grade 3 and 4 toxicities was 56.1% (95% confidence interval 53.5-58.6), with marked between-study heterogeneity (I2 = 96.8%). Toxicity profiles varied considerably depending on the type of TKI, the cancer type, and the specific patient characteristics. In particular, Asian patients and elderly people had higher prevalences of severe toxicities, with pazopanib being the best-tolerated drug. For patients treated with sunitinib, particularly those with metastatic RCC, there was no significant difference in terms of toxicity according to the regimen schedule.

CONCLUSIONS

This meta-analysis highlights the toxicity profiles of anti-angiogenic TKI monotherapies, and thus enables high-level recommendations for the choice of anti-angiogenic TKIs on the basis of the patient's age, ethnicity, comorbidities, and comedications, for personalized treatment.

Drug-drug interactions associated with FLT3 inhibitors for acute myeloblastic leukemia: current landscape

INTRODUCTION

FLT3 inhibitors (FLT3i) are drugs in which there is limited experience and not yet enough information on the mechanisms of absorption, transport, and elimination; but especially on the potential drug-drug interactions (DDIs). There are therefore risks in the management of FLT3i DDIs (i.e. sorafenib, ponatinib, crenolanib, midostaurin, quizartinib, and gilteritinib) and ignoring them can compromise therapeutic success in acute myeloid leukemia (AML) treatment, in complex patients and secondary pathologies.

AREAS COVERED

This review summarizes the DDIs of FLT3i with P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting (OAT), organic cationic transporting (OCT), cytochrome P450 (CYP) subunits, and other minor metabolic/transport pathways. EMBASE, PubMed, the Cochrane Central Register and the Web of Science were searched. The last literature search was performed on the 14 February 2022.

EXPERT OPINION

FLT3i will be combined with other therapeutic agents (supportive care, doublet, or triplet therapy) and in different clinical settings, which means a greater chance of controlling and even eradicating the disease effectively, but also an increased risk to patients due to potential DDIs. Healthcare professionals should be aware of the potential interactions that may occur and be vigilant in monitoring those patients who are receiving any potentially interacting drug.

Predicting disruptions to drug pharmacokinetics and the risk of adverse drug reactions in non-alcoholic steatohepatitis patients

The liver plays a central role in the pharmacokinetics of drugs through drug metabolizing enzymes and transporters. Non-alcoholic steatohepatitis (NASH) causes disease-specific alterations to the absorption, distribution, metabolism, and excretion (ADME) processes, including a decrease in protein expression of basolateral uptake transporters, an increase in efflux transporters, and modifications to enzyme activity. This can result in increased drug exposure and adverse drug reactions (ADRs). Our goal was to predict drugs that pose increased risks for ADRs in NASH patients. Bibliographic research identified 71 drugs with reported ADRs in patients with liver disease, mainly non-alcoholic fatty liver disease (NAFLD), 54 of which are known substrates of transporters and/or metabolizing enzymes. Since NASH is the progressive form of NAFLD but is most frequently undiagnosed, we identified other drugs at risk based on NASH-specific alterations to ADME processes. Here, we present another list of 71 drugs at risk of pharmacokinetic disruption in NASH, based on their transport and/or metabolism processes. It encompasses drugs from various pharmacological classes for which ADRs may occur when used in NASH patients, especially when eliminated through multiple pathways altered by the disease. Therefore, these results may inform clinicians regarding the selection of drugs for use in NASH patients.

A Profile of Avelumab Plus Axitinib in the Treatment of Renal Cell Carcinoma

Until recently, the approved first-line treatment for metastatic RCC (mRCC) consisted of tyrosine kinase inhibitors (TKI) targeting the vascular endothelial growth factor receptors (VEGFR) monotherapy. The landscape of first-line treatment has been transformed in the last few years with the advent of immune checkpoint inhibitors (ICI) or VEGFR TKI plus ICI combinations. This article focuses on the profile of one of these ICI plus VEGFR TKI combination, avelumab plus axitinib. We detail the characteristics of each drug separately, and then we explore the rationale for their association, its efficacy and the resulting toxicity. Finally, we examine the factors associated with avelumab plus axitinib outcomes, and their impact on therapeutic strategy.

Antiangiogenic Drugs in NASH: Evidence of a Possible New Therapeutic Approach

Non-alcoholic fatty liver disease is the most common liver disorder worldwide, and its progressive form non-alcoholic steatohepatitis (NASH) is a growing cause of liver cirrhosis and hepatocellular carcinoma (HCC). Lifestyle changes, which are capable of improving the prognosis, are hard to achieve, whereas a pharmacologic therapy able to combine efficacy and safety is still lacking. Looking at the pathophysiology of various liver diseases, such as NASH, fibrosis, cirrhosis, and HCC, the process of angiogenesis is a key mechanism influencing the disease progression. The relationship between the worsening of chronic liver disease and angiogenesis may suggest a possible use of drugs with antiangiogenic activity as a tool to stop or slow the progression of the disorder. In this review, we highlight the available preclinical data supporting a role of known antiangiogenic drugs (e.g., sorafenib), or phytotherapeutic compounds with multiple mechanism of actions, including also antiangiogenic activities (e.g., berberine), in the treatment of NASH.

Prevalence of drug-drug interactions in sarcoma patients: key role of the pharmacist integration for toxicity risk management

BACKGROUND

The risk of drug-drug interactions (DDI) has become a major issue in cancer patients. However, data in sarcoma patients are scarce. We aimed to evaluate the frequency and the factors associated with DDI with antitumor treatments, and to evaluate the impact of a pharmacist evaluation before anticancer treatment.

PATIENTS AND METHODS

We performed a retrospective review of consecutive sarcoma patients starting chemotherapy (CT) or Tyrosine kinase inhibitor (TKI). A pharmacist performed medication reconciliation and established an early toxicity risk assessment. Potential DDI with antitumor drugs were identified using Micromedex electronic software.

RESULTS

One hundred and twenty-two soft-tissue and 80 bone sarcoma patients (103 males, median age 50 years,) were included before CT (86%) or TKI (14%). The median number of medications was 3; 34 patients (22% of patients with medication reconciliation) reported complementary medicine use. 37 potential DDI classified as major, were identified (12% of the 243 pre-therapeutic assessments). In multivariate analysis, TKI (p < 0.0001), proton pump inhibitor (p = 0.026) and antidepressant (p < 0.001) were identified as risk factors of DDI (p < 0.02). Only marital status (p = 0.003) was associated with complementary medicine use. A pharmacist performed 157 medication reconciliations and made 71 interventions among 59 patients (37%). In multivariate analysis, factors associated with pharmacist intervention were: complementary medicines (p = 0.004), drugs number (p = 0.005) and treatment with TKI (p = 0.0002) CONCLUSIONS: Clinical interventions on DDI are more frequently required among sarcoma patients treated with TKI than CT. Multidisciplinary risk assessment including a medication reconciliation by a pharmacist could be crucial to prevent DDI with TKI.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

A Pharmacokinetic Interaction Study of Sorafenib and Iced Teas in Rats Using UPLC-MS/MS: An Illustration of Beverage-Drug Interaction

Iced teas (ITs), also known as ready-to-drink teas, have gained much popularity among many nations. The modulatory effect of tea beverages on CYP3A4 increases the possibility of their potential interactions with many coadministered medications. Being a substrate of CYP3A4, sorafenib (SOR), the first-line therapy for the treatment of hepatocellular carcinoma, shows a great probability to exhibit pharmacokinetic (PK) interaction with ITs. For this purpose, different groups of Wistar rats were given oral doses of SOR (40 mg/kg), along with different types of ITs. The concentration of SOR in rat plasma was determined using UPLC-MS/MS. Chromatographic analysis was performed on a C18 analytical column, Acquity UPLC BEH™ (100 × 1.0 mm, i.d., 1.7 μm particle size), using erlotinib (ERL) as an internal standard. Isocratic elution was performed with a mobile phase consisting of two solvents: solvent A (water with 0.1% formic acid) and solvent B (acetonitrile with 0.1% formic acid), in a ratio of 30 : 70, v/v, respectively. Quantitation was performed using MRM of the transitions from protonated precursor ions [M+H]⁺ to product ions at m/z 465.12 > 252.02 (SOR) and m/z 394.29 > 278.19 (ERL). The method was fully validated as per the FDA guidance for bioanalytical method validation in the concentration range of 2.5–500 ng/mL. Different PK parameters were calculated for SOR in all rat groups and groups administered with ITs and SOR, compared with groups with simply water and SOR. Experimental data revealed that ITs caused a general reduction in SOR bioavailability; an approximate reduction of 30% was recorded for all types of tested ITs. These data indicate that ITs could affect the PK profile of SOR in rats.

Onco-cardiology: Drug-drug interactions of antineoplastic and cardiovascular drugs

Cardiovascular diseases (CVD) and cancer are still the leading causes of death. There are many common etiologic factors, especially smoking and obesity. Therefore, it is not uncommon for CVD and cancer to coexist. Drug-drug interactions (DDIs) inevitably occur in this group of patients, where polypharmacy is increasing due to older age and multiple comorbidities. However, multidisciplinary studies, especially close collaboration of medical oncologists and cardiologists, who deals with the diagnosis and treatment of these diseases, awareness and preventive approaches to DDIs may reduce serious morbidity and mortality. In this review, information about the common treatments used in cardiology and oncology and possible DDIs are discussed.

Complex Drug-Drug-Gene-Disease Interactions Involving Cytochromes P450: Systematic Review of Published Case Reports and Clinical Perspectives

Drug pharmacokinetics (PK) is influenced by multiple intrinsic and extrinsic factors, among which concomitant medications are responsible for drug-drug interactions (DDIs) that may have a clinical relevance, resulting in adverse drug reactions or reduced efficacy. The addition of intrinsic factors affecting cytochromes P450 (CYPs) activity and/or expression, such as genetic polymorphisms and diseases, may potentiate the impact and clinical relevance of DDIs. In addition, greater variability in drug levels and exposures has been observed when such intrinsic factors are present in addition to concomitant medications perpetrating DDIs. This variability results in poor predictability of DDIs and potentially dramatic clinical consequences. The present review illustrates the issue of complex DDIs using systematically searched published case reports of DDIs involving genetic polymorphisms, renal impairment, cirrhosis, and/or inflammation. Current knowledge on the impact of each of these factors on drug exposure and DDIs is summarized and future perspectives for the management of such complex DDIs in clinical practice are discussed, including the use of advanced Computerized Physician Order Entry (CPOE) systems, the development of model-based dose optimization strategies, and the education of healthcare professionals with respect to personalized medicine.

Axitinib in the treatment of renal cell carcinoma: design, development, and place in therapy

Since 2005, the approved first-line treatment of metastatic renal cell carcinoma consists in tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor receptors (VEGFRs). Axitinib is an oral second-generation TKI and a potent VEGFR inhibitor with a half maximal inhibitory concentration for the VEGF family receptors 10-fold lower than other TKIs. Axitinib activity in renal cell carcinoma (RCC) patients has been studied in various settings and particularly as second-line treatment. In this setting, axitinib with clinically based dose escalation compared to sorafenib has demonstrated an improvement in progression-free survival in a randomized Phase III trial leading to US Food and Drug Administration approval. In the first-line setting, axitinib failed to demonstrate improved efficacy over sorafenib, but the field of RCC treatment is rapidly changing with novel TKIs as cabozantinib or the emergence of check point inhibitors as nivolumab and the place of axitinib in therapy is therefore challenged. In this review, we focus on axitinib pharmacological and clinical properties in RCC patients and discuss its place in the treatment of patients with RCC.

[Tyrosine kinase inhibiting the VEGF pathway and elderly people: Tolerance, pre-treatment assessment and side effects management]

Angiogenesis inhibition is a major antitumor strategy that has emerged during the last decade. Oral tyrosine kinase inhibitors (TKI) targeting the VEGF receptor, including sunitinib, sorafenib, axitinib, regorafenib, pazopanib, and vandetanib reduce tumor growth and metastasis. These agents are approved for the treatment of metastatic diseases in first or second-line. They display a narrow therapeutic index. However, data in the elderly and/or in patients with multiple illnesses remain scarce. This population is classically excluded from clinical trials. The aim of this review is to provide an overview of existing literature regarding antiangiogenic TKI tolerance in the elderly (>70 years old). We also highlight key points of the pre-therapeutic evaluation and summarize the management of common toxicities.

Management of dose variability and side effects for individualized cancer pharmacotherapy with tyrosine kinase inhibitors

Molecular-targeted therapies with tyrosine kinase inhibitors (TKIs) have provided a major breakthrough in cancer treatment. These agents are given orally and demonstrated to be substrates for drug transporters. In clinical settings, TKIs are mainly used at a fixed dose, but wide interpatient variability has been observed in their pharmacokinetics and/or pharmacodynamics. Genetic polymorphisms of ABC transporters, drug-drug interaction and adherence are among the factors causing such variation. To overcome these problems, therapeutic drug monitoring has been applied in clinical practice for patient care. Skin disorders are frequently observed as adverse drug reactions when using TKIs, and are commonly managed by symptomatic therapy based on clinical experience. Recent studies have provided some insights into the molecular mechanisms underlying skin disorders induced by TKIs. This review article summarizes the accumulated clinical and basic pharmacological evidence of TKIs, focusing on erlotinib, sorafenib and sunitinib.

Effect of glucuronidation on transport and tissue accumulation of tyrosine kinase inhibitors: consequences for the clinical management of sorafenib and regorafenib

INTRODUCTION

UDP-glucuronosyltransferases (UGTs) are a multigenic family of enzymes responsible for the glucuronidation reaction. Many therapeutic classes of drugs used in solid tumors are UGT substrates, including cancer therapies.

AREAS COVERED

This article describes the tyrosine kinase inhibitors (TKIs) undergoing hepatic glucuronidation; its effect on transport and tissue accumulation and the clinical consequences of this particular metabolism. A PubMed search concerning the pharmacokinetics of the TKIs was performed. All are extensively metabolized by CYP450. Two TKIs, sorafenib and regorafenib, also have a major UGT-mediated metabolism and were therefore studied.

EXPERT OPINION

The prescription of the same dose of sorafenib and regorafenib for all patients may be inappropriate since at each enzymatic step of this multistep metabolism inter-individual fluctuations exist. Having a non-exclusive CYP-mediated route of metabolism may reduce the risk of variability in drug exposure when CYP3A4 substrates are concomitantly given. Several clinical consequences derive from this pharmacokinetic particularity of sorafenib and regorafenib. Since no clear difference distinguishes TKIs in efficacy in large randomized trials, the differences for the clinical management of their toxicity is a critical aspect.

Incidence and risk of sorafenib-induced hypertension: a systematic review and meta-analysis

Hypertension is one of the major side effects of sorafenib, and reported incidences vary substantially among clinical trials. A systematic review was conducted using Medline, PubMed, Embase, and the Cochrane Library for all longitudinal studies to investigate the incidence and risk of hypertension events in cancer patients treated with sorafenib. A total of 14 randomized controlled trials and 39 prospective single-arm trials involving 13,555 patients were selected for the meta-analysis. The relative risk of all-grade and high-grade hypertension associated with sorafenib were 3.07 (95% confidence interval [CI], 2.05–4.60; P<.01) and 3.31 (95% CI, 2.21–4.95; P<.01), respectively. The overall incidence of sorafenib-induced all-grade and high-grade hypertension were 19.1% (95% CI, 15.8%–22.4%) and 4.3% (95% CI, 3.0%–5.5%), respectively. A significantly higher incidence of hypertension was noted in patients with renal cell carcinoma (RCC) compared with those with non-RCC malignancies (all-grade: 24.9% [95% CI, 19.7%–30.1%] vs 15.7%[95% CI, 12.1%–19.3%]; P<.05; high-grade:8.6% [95% CI, 6.0%–11.2%] vs 1.8% [95% CI, 0.9%–2.6%]; P<.05). The trials with median progression-free survival (PFS) longer than 5.3 months (mean PFS) demonstrated a significantly higher incidence of high-grade hypertension than trials with shorter PFS (6.3% [95% CI, 4.1%–8.5%] vs 2.6% [95% CI, 1.4%– 3.8%]; P<.05). Findings of the meta-analysis indicated a significantly high risk of sorafenib-induced hypertension. Patients with RCC have a significantly higher incidence of hypertension and the occurrence of hypertension may be associated with improved prognosis.

Sorafenib metabolism is significantly altered in the liver tumor tissue of hepatocellular carcinoma patient

Background

Sorafenib, the drug used as first line treatment for hepatocellular carcinoma (HCC), is metabolized by cytochrome P450 (CYP) 3A4-mediated oxidation and uridine diphosphate glucuronosyl transferase (UGT) 1A9-mediated glucuronidation. Liver diseases are associated with reduced CYP and UGT activities, which can considerably affect drug metabolism, leading to drug toxicity. Thus, understanding the metabolism of therapeutic compounds in patients with liver diseases is necessary. However, the metabolism characteristic of sorafenib has not been systematically determined in HCC patients.

Methods

Sorafenib metabolism was tested in the pooled and individual tumor hepatic microsomes (THLMs) and adjacent normal hepatic microsomes (NHLMs) of HCC patients (n = 18). Commercial hepatic microsomes (CHLMs) were used as a control. In addition, CYP3A4 and UGT1A9 protein expression in different tissues were measured by Western blotting.

Results

The mean rates of oxidation and glucuronidation of sorafenib were significantly decreased in the pooled THLMs compared with those in NHLMs and CHLMs. The maximal velocity (V_max) of sorafenib oxidation and glucuronidation were approximately 25-fold and 2-fold decreased in the pooled THLMs, respectively, with unchanged K_m values. The oxidation of sorafenib in individual THLMs sample was significantly decreased (ranging from 7 to 67-fold) than that in corresponding NHLMs sample. The reduction of glucuronidation in THLMs was observed in 15 out of 18 patients’ samples. Additionally, the level of CYP3A4 and UGT1A9 expression were both notably decreased in the pooled THLMs.

Conclusions

Sorafenib metabolism was remarkably decreased in THLMs. This result was associated with the down regulation of the protein expression of CYP3A4 and UGT1A9.

Drug safety evaluation of sorafenib for treatment of solid tumors: consequences for the risk assessment and management of cancer patients

INTRODUCTION

Sorafenib is a multi-tyrosine kinase inhibitor (TKI). Considerable clinical experience has been accumulated since its first Phase III clinical trial in metastatic renal cancer patients in 2007. The management of its early acute toxicity in fit patients is well known. The management of prolonged treatment becomes the new challenge.

AREAS COVERED

Using sorafenib as a key word for PubMed search, we review preclinical and clinical data and discuss the pharmacokinetics and pharmacodynamics of sorafenib, its acute and cumulative toxicities and their consequences for patient management.

EXPERT OPINION

The systematic multi-disciplinary risk assessment of cancer patients prior to TKI initiation reduces the risks of acute and late toxicity, especially drug-drug interactions and arterial risks. Sarcopenia is now identified as a major risk of severe toxicity. The very diverse clinical pictures of cumulative toxicity must be known. The monitoring of sorafenib systemic exposure is helpful especially in elderly patients. Moreover, at disease progression, it allows distinguishing between underexposure to sorafenib and truly acquired resistance to the drug. The optimal use of sorafenib should allow improving the reported results of flat-dose. Finally, most of this knowledge could be used for the development and optimal use of the other TKIs.

Drug interactions with solid tumour-targeted therapies

Drug interactions are an on-going concern in the treatment of cancer, especially when targeted therapies, such as tyrosine kinase inhibitors (TKI) or mammalian target of rapamycin (mTOR) inhibitors, are being used. The emergence of elderly patients and/or patients with both cancer and other chronic co-morbidities leads to polypharmacy. Therefore, the risk of drug-drug interactions (DDI) becomes a clinically relevant issue, all the more so as TKIs and mTOR inhibitors are essentially metabolised by cytochrome P450 enzymes. These DDIs can result in variability in anticancer drug exposure, thus favouring the selection of resistant cellular clones or the occurrence of toxicity. This review provides a comprehensive overview of DDIs that involve targeted therapies approved by the FDA for the treatment of solid tumours for more than 3 years (sorafenib, sunitinib, erlotinib, gefitinib, imatinib, lapatinib, everolimus, temsirolimus) and medicinal herb or drugs. This review also provides some guidelines to help oncologists and pharmacists in their clinical practice.

Interactions between oral antineoplastic agents and concomitant medication: a systematic review

INTRODUCTION

In recent years, the number of oral antitumoral agents has considerably increased. Oral administration increases the risk of interactions, because most oral anticancer drugs are taken on a daily basis. Interactions can increase exposure to antitumoral agents or cause treatment failure. Many antitumoral drugs undergo enzymatic metabolism by cytochrome P450. As some act as inducers or inhibitors of one or more isoenzymes, they can lead to decreases or increases in plasma concentrations of concomitant drugs. Hence, cytostatic drugs can act not only as victims but also as perpetrators. P-glycoprotein, an efflux transporter, can also be involved in pharmacokinetic interactions.

AREAS COVERED

A Medline search was performed to summarize the available evidence of the most clinically relevant interactions between oral chemotherapy agents and other drugs. The search covered the period from 1966 until August 2012 for each antitumoral drug using the medical subject headings 'Drug Interactions' OR 'Pharmacokinetics'. While the present review is not exhaustive, it aims to increase clinicians' awareness of potential drug-drug interactions.

EXPERT OPINION

As cancer patients are often polymedicated and treated by different physicians, the risk of drug interactions between antitumoral agents and other medications is high. More clinical interaction studies are encouraged to ensure appropriate antineoplastic pharmacokinetics in clinical practice.

Early sorafenib-induced toxicity is associated with drug exposure and UGTIA9 genetic polymorphism in patients with solid tumors: a preliminary study

Background

Identifying predictive biomarkers of drug response is of key importance to improve therapy management and drug selection in cancer therapy. To date, the influence of drug exposure and pharmacogenetic variants on sorafenib-induced toxicity remains poorly documented. The aim of this pharmacokinetic/pharmacodynamic (PK/PD) study was to investigate the relationship between early toxicity and drug exposure or pharmacogenetic variants in unselected adult outpatients treated with single-agent sorafenib for advanced solid tumors.

Methods

Toxicity was recorded in 54 patients on days 15 and 30 after treatment initiation and sorafenib exposure was assessed in 51 patients. The influence of polymorphisms in CYP3A5, UGT1A9, ABCB1 and ABCG2 was examined in relation to sorafenib exposure and toxicity. Clinical characteristics, drug exposure and pharmacogenetic variants were tested univariately for association with toxicities. Candidate variables with p<0.1 were analyzed in a multivariate analysis.

Results

Gender was the sole parameter independently associated with sorafenib exposure (p = 0.0008). Multivariate analysis showed that increased cumulated sorafenib (AUC_cum) was independently associated with any grade ≥3 toxicity (p = 0.037); UGT1A9 polymorphism (rs17868320) with grade ≥2 diarrhea (p = 0.015) and female gender with grade ≥2 hand-foot skin reaction (p = 0.018). Using ROC curve, the threshold AUC_cum value of 3,161 mg/L.h was associated with the highest risk to develop any grade ≥3 toxicity (p = 0.018).

Conclusion

In this preliminary study, increased cumulated drug exposure and UGT1A9 polymorphism (rs17868320) identified patients at high risk for early sorafenib-induced severe toxicity. Further PK/PD studies on larger population are warranted to confirm these preliminary results.

The combined use of edaravone, diuretics, and nonsteroidal anti-inflammatory drugs caused acute kidney injury in an elderly patient with chronic kidney disease

The purpose of this study was to draw attention to the fact that the combined use of edaravone, diuretics, and nonsteroidal anti-inflammatory drugs (NSAIDs) may lead to acute kidney injury. This study was a case report of acute kidney injury resulting from the combined use of the aforementioned types of drugs. A 77-year-old male patient with chronic kidney disease (third stage) who was treated with a combination of edaravone, diuretics, and NSAIDs showed significantly increased blood urea nitrogen and creatinine. Interestingly, the blood urea nitrogen and creatinine levels returned to pretreatment levels after the medications were stopped. The patient's score on the Naranjo Adverse Drug Reaction Probability Scale was a nine, and the score on the Drug Interaction Probability Scale was a five. For elderly patients with chronic kidney disease, the combined use of edaravone, diuretics, and NSAIDs should be avoided.

Population pharmacokinetic analysis of sorafenib in patients with solid tumours

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Sorafenib is a multikinase inhibitor with activity against B-raf, C-raf, VEGFR2, PDGFRβ and FGFR1. Sorafenib is clinically approved for the treatment of renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC). The pharmacokinetics (PK) of sorafenib are highly variable between subjects. Sorafenib exposure increases less than dose proportionally (likely due to limited solubility). Sorafenib undergoes enterohepatic recycling (EHC).

WHAT THIS STUDY ADDS

This is the first study to characterize the PK of sorafenib using a model based on sorafenib's known disposition characteristics such as delayed/solubility-limited GI absorption and EHC. The parameterization of the EHC model used a square wave function to describe the gall bladder emptying. This study evaluated the effect of baseline bodyweight, BSA, age, gender, liver function parameters, kidney function parameters and genotype with respect to CYP3A4*1B, CYP3A5*3C, UGT1A9*3 and UGT1A9*5 on sorafenib PK. No clinically important covariates were identified. This model can be used to simulate and explore alternative dosing regimens and to develop exposure-response relationships for sorafenib.

AIMS

To characterize the pharmacokinetics (PK) of sorafenib in patients with solid tumours and to evaluate the possible effects of demographic, clinical and pharmacogenetic (CYP3A4*1B, CYP3A5*3C, UGT1A9*3 and UGT1A9*5) covariates on the disposition of sorafenib.

METHODS

PK were assessed in 111 patients enrolled in five phase I and II clinical trials, where sorafenib 200 or 400 mg was administered twice daily as a single agent or in combination therapy. All patients were genotyped for polymorphisms in metabolic enzymes for sorafenib. Population PK analysis was performed by using nonlinear mixed effects modelling (NONMEM). The final model was validated using visual predictive checks and nonparametric bootstrap analysis.

RESULTS

A one compartment model with four transit absorption compartments and enterohepatic circulation (EHC) adequately described sorafenib disposition. Baseline bodyweight was a statistically significant covariate for distributional volume, accounting for 4% of inter-individual variability (IIV). PK model parameter estimates (range) for an 80 kg patient were clearance 8.13 l h(-1) (3.6-22.3 l h(-1) ), volume 213 l (50-1000 l), mean absorption transit time 1.98 h (0.5-13 h), fraction undergoing EHC 50% and average time to gall bladder emptying 6.13 h.

CONCLUSIONS

Overall, population PK analysis was consistent with known biopharmaceutical/PK characteristics of oral sorafenib. No clinically important PK covariates were identified.

Treatment of bevacizumab-induced hypertension by amlodipine

BACKGROUND

Hypertension is a common toxicity of anti-VEGF agents, but its optimal treatment remains to define. This study aimed to describe the efficacy and tolerability of amlodipine, a calcium channel blocker, in patients with metastatic malignancies treated with bevacizumab, a humanized monoclonal antibody to VEGF.

PATIENTS AND METHODS

One hundred and eighty-seven patients with advanced or metastatic NSCLC, colorectal or ovarian cancer receiving bevacizumab (5 mg/kg every 2 weeks or 7.5 mg/kg every 3 weeks) and chemotherapy were eligible for this analysis. Blood pressure was measured at home twice daily according to international guidelines. Patients received amlodipine 5 mg daily for grade ≥ 2 bevacizumab-induced hypertension.

RESULTS

Twenty-six patients received amlodipine 5 mg daily for de novo hypertension (group A), and another 10 patients received amlodipine for exacerbation of previously existing hypertension (group B). Hypertension was controlled within 7 days under amlodipine in 23/26 (88.5%, 95%CI: 76.2-100) patients in group A, and 8/10 (80%, 95%CI: 55.2-100) patients in group B, with a favourable toxicity profile.

CONCLUSIONS

Amlodipine 5 mg daily appears safe and efficient for the treatment of hypertension in patients receiving bevacizumab at a dose-intensity of 2.5 mg/kg/week. Further prospective studies are warranted to confirm these results.