Differential effects of hepatic cirrhosis on the intrinsic clearances of sorafenib and imatinib by CYPs in human liver

Effects of Berberis vulgaris, and its active constituent berberine on cytochrome P450: a review

The cytochrome P450 (CYP450) family is crucial for metabolizing drugs and natural substances. Numerous compounds, such as pharmaceuticals and dietary items, can influence CYP activity by either enhancing or inhibiting these enzymes, potentially leading to interactions between drugs or between drugs and food. This research explores the impact of barberry and its primary component "berberine" on key human CYP450 enzymes. The text discusses the effects of this plant on the 12 primary human CYP450 enzymes, with summarized data presented in tables. Berberine exerts an influence on the function of various CYP450 isoforms, including CYP3A4/5, CYP2D6, CYP2C9, CYP2E1, CYP1A1/2, and most isoforms within the CYP2B subfamily. Given the significant role of these CYP450 isoforms in metabolizing commonly used drugs and endogenous substances, as well as activating procarcinogens into carcinogenic metabolites, the influence of barberry and its active constituent on these enzymes may impact the pharmacokinetics and toxicity profiles of various compounds. More specifically, regarding the crucial role of CYP2D6 and CYP3A4 in metabolizing clinically used drugs, and the inhibitory effects of berberine on these two CYP450 isoforms, it seems that the most important drug interaction of berberine that should be considered is related to its inhibitory effect on CYP2D6 and CYP3A4. In conclusion, due to the impact of barberry on multiple CYP450 isoforms, healthcare providers should conduct thorough consultations and investigations to ensure patient safety and prevent any potential adverse interactions before recommending the consumption of these herbs. Additional research, particularly clinical trials is crucial for preventing any potentially adverse interactions in patients who consume this herb.

Physiologically-based pharmacokinetic modeling predicts the drug interaction potential of GLS4 in co-administered with ritonavir

GLS4 is a first-in-class hepatitis B virus (HBV) capsid assembly modulator (class I) that is co-administered with ritonavir to maintain the anticipated concentration required for the effective antiviral activity of GLS4. In this study, the first physiologically-based pharmacokinetic (PBPK) model for GLS4/ritonavir was successfully developed. The predictive performance of the PBPK model was verified using data from 39 clinical studies, including single-dose, multiple-dose, food effects, and drug-drug interactions (DDI). The PBPK model accurately described the PK profiles of GLS4 and ritonavir, with predicted values closely aligning with observed data. Based on the verified GLS4/ritonavir model, it prospectively predicts the effect of hepatic impairment (HI) and DDI on its pharmacokinetics (PK). Notably, CYP3A4 inducers significantly influenced GLS4 exposure when co-administered with ritonavir; co-administered GLS4 and ritonavir significantly influenced the exposure of CYP3A4 substrates. Additionally, with the severity of HI increased, there was a corresponding increase in the exposure to GLS4 when co-administered with ritonavir. The GLS4/ritonavir PBPK model can potentially be used as an alternative to clinical studies or guide the design of clinical trial protocols.

Incorporation and Performance Verification of Hepatic Portal Blood Flow Shunting in Minimal and Full PBPK Models of Liver Cirrhosis

Patho-physiological changes in liver cirrhosis create portacaval shunts that allow blood flow to bypass the hepatic portal vein into the systemic circulation affecting drug pharmacokinetics (PKs). The objectives of this work were to implement a physiologically-based pharmacokinetic (PBPK) framework describing shunted blood flows in virtual patients with differing degrees of liver cirrhosis; and to assess the minimal and full PBPK model's performance using drugs with intermediate to high hepatic extraction. Single dose concentration-time profiles and PK parameters for oral ibrutinib, midazolam, propranolol, and buspirone were simulated in healthy volunteers (HVs) and subjects with cirrhosis (Child-Pugh severity score (CP-A, CP-B, or CP-C)). Model performance was verified by comparing predicted to observed fold-changes in PK parameters between HVs and cirrhotic subjects. The verified model was used to simulate the PK changes for simvastatin in patients with cirrhosis. The predicted area under the curve ratios (AUCCirr :AUCHV ) for ibrutinib were 3.38, 6.87, and 11.46 using the minimal PBPK model with shunt and 1.61, 2.58, and 4.33 without the shunt, these compared with observed values of 4.33, 8.14, and 9.04, respectively. For ibrutinib, propranolol, and buspirone, including a shunt in the PBPK model improved the prediction of the AUCCirr :AUCHV and maximum plasma concentration ratios (CmaxCirr :CmaxHV ). For midazolam, an intermediate extraction drug, the differences were less clear. Simulated simvastatin dose adjustments in cirrhosis suggested that 20 mg in CP-A and 10 mg in CP-B could be used clinically. A mechanistic model-informed understanding of the anatomic and pathophysiology of cirrhosis will facilitate improved dose prediction and adjustment in this vulnerable population.

Pharmacokinetic considerations for angiogenesis inhibitors used to treat hepatocellular carcinoma: an overview

INTRODUCTION

Hepatocellular carcinoma (HCC) is the fifth malignancy in terms of frequency and the fourth malignancy in terms of cancer-related death worldwide. Systemic therapy of advanced HCC has probably gone through the greatest wave of change in the last decade, with the introduction of several anti-angiogenic drugs and immune checkpoint inhibitors, able to significantly improve patients' prognosis.

AREAS COVERED

In this review, we summarize the pharmacokinetic characteristic of the antiangiogenic drugs currently approved for the treatment of HCC, from oral tyrosine kinase inhibitors (sorafenib, lenvatinib, regorafenib and cabozantinib) to monoclonal antibodies (bevacizumab and ramucirumab), focusing on the main aspects that differ among compounds from the same class, on factors that can exert an influence on pharmacokinetic parameters and the main issues that could limit their clinical use.

EXPERT OPINION

Anti-angiogenic drugs have different profiles in terms of bioavailability, metabolism, elimination and interindividual variability in their pharmacokinetics and effectiveness. More studies should be developed to address the intrinsic and extrinsic factors influencing pharmacokinetics parameters to improve the individual therapeutic response and, furthermore, to evaluate the benefit and the harm of systemic therapy for advanced HCC in selected patients with liver impairment.

Review article: time to revisit Child-Pugh score as the basis for predicting drug clearance in hepatic impairment

BACKGROUND

Prescription information for many drugs entering the market lacks dosage guidance for hepatic impairment. Dedicated studies for assessing the fate of drugs in hepatic impairment commonly stratify patients using Child-Pugh score. Child-Pugh is a prognostic clinical score with limitations in reflecting the liver's metabolic capacity.

AIMS

To demonstrate the need for better drug dosing approaches in hepatic impairment, summarise the current status, identify knowledge gaps related to drug kinetic parameters in hepatic impairment, propose solutions for predicting the liver disease impact on drug exposure and discuss barriers to dosing guidance in those patients.

METHODS

Relevant reports on dosage adjustment in hepatic impairment were analysed concerning the prediction of the impairment impact on drug kinetics using physiologically-based pharmacokinetic (PBPK) modelling.

RESULTS

PBPK models are suggested as a potential framework to understand drug clearance changes in hepatic impairment. Quantifying changes in abundance and activity of drug-metabolising enzymes and transporters, understanding the impact of shunting, and accounting for interindividual variations in drug absorption could help in extending the success of these models in hepatically-impaired populations. These variables might not correlate with Child-Pugh score as a whole. Therefore, new metabolic activity markers, imaging techniques and other scoring systems are proposed to either support or substitute Child-Pugh score.

CONCLUSIONS

Many physiological changes in hepatic impairment determining the fate of drugs do not necessarily correlate with Child-Pugh score. Quantifying these changes in individual patients is essential in future hepatic impairment studies. Further studies assessing Child-Pugh alternatives are recommended to allow better prediction of drug exposure.

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.

Inhibition of Hepatic CYP2D6 by the Active N-Oxide Metabolite of Sorafenib

The multikinase inhibitor sorafenib (SOR) is used to treat patients with hepatocellular and renal carcinomas. SOR undergoes CYP-mediated biotransformation to a pharmacologically active N-oxide metabolite (SNO) that has been shown to accumulate to varying extents in individuals. Kinase inhibitors like SOR are frequently coadministered with a range of other drugs to improve the efficacy of anticancer drug therapy and to treat comorbidities. Recent evidence has suggested that SNO is more effective than SOR as an inhibitor of CYP3A4-mediated midazolam 1'-hydroxylation. CYP2D6 is also reportedly inhibited by SOR. The present study assessed the possibility that SNO might contribute to CYP2D6 inhibition. The inhibition kinetics of CYP2D6-mediated dextromethorphan O-demethylation were analyzed in human hepatic microsomes, with SNO found to be ~ 19-fold more active than SOR (K_is 1.8 ± 0.3 μM and 34 ± 11 μM, respectively). Molecular docking studies of SOR and SNO were undertaken using multiple crystal structures of CYP2D6. Both molecules mediated interactions with key amino acid residues in putative substrate recognition sites of CYP2D6. However, a larger number of H-bonding interactions was noted between the N-oxide moiety of SNO and active site residues that account for its greater inhibition potency. These findings suggest that SNO has the potential to contribute to pharmacokinetic interactions involving SOR, perhaps in those individuals in whom SNO accumulates.

LC-ESI-QTOF-MS analysis utilizing gas-phase fragmentation reactions subjected to ESI-IS-CID and ESI-CID-MS/MS conditions to study the degradation behaviour of sorafenib tosylate: NMR and in vitro cytotoxicity and apoptosis detection studies of hydrolytic degradation products

The present study was to investigate the degradation profile of sorafenib tosylate (SORA), a potent oral multi-kinase inhibitor under various stress conditions as per ICH (Q1A (R2)) guidelines. Separation of SORA and its degradation products (DP-1-DP-5) was achieved on Acquity UPLC BEH C18 (100 mm × 2.1 mm × 1.7 μm) column using a gradient elution of 0.1% formic acid and acetonitrile at a flow rate of 0.3 mL/min within 12 min. High resolution quadruple time-of-flight mass spectrometer (Q-TOF/MS) was utilized for characterization of all DPs. In ESI/CID-MS/MS experiments, the protonated DP-1 and DP-2 exhibited few interesting product ions which provide a compelling evidence for the compounds to undergo gas phase rearrangement reaction justified by its mechanistic explanation in support with density functional theory (DFT). In-source collision-induced dissociation (IS-CID) fragmentation using ESI/APCI-MS analysis exhibited the formation of N-deoxygenated product ion peak corresponds to pyridine N-oxide moiety as in DP-5. Further, major hydrolytic DPs (DP-2 and DP-3) were isolated on preparative HPLC and structural elucidation was done using ID NMR (¹H, ¹³C and DEPT-135) experiments. In vitro cytotoxicity study for SORA and its isolated DPs were assessed by observing morphological changes in HepG2 cell lines under phase-contrast microscopy and MTT assay. Taken together, it was known that DP-2 and DP-3 were less potent with a cell viability of more than 90% and IC₅₀ >50 μM in comparison with SORA (IC₅₀ = 2.99 ± 0.35 μM). The developed method was validated in terms of specificity, limit of detection, limit of quantification, linearity, accuracy, precision and robustness.

Interaction between phytotherapy and oral anticancer agents: prospective study and literature review

Cancer is becoming more prevalent in elderly patient. Due to polypharmacy, older adults with cancer are predisposed to drug-drug interactions. There is also an increasing interest in the use of complementary and alternative medicine (CAM). Thirty to seventy percent of patients with cancer have used CAM. Through pharmaceutical counseling sessions, we can provide advices on herb-drug interactions (HDI). All the patients seen in pharmaceutical counseling sessions were prospectively included. Information was collected during these sessions: prescribed medication (oral anticancer agents (OAA) and other drugs), CAM (phytotherapy especially), and use of over-the-counter (OTC) drugs. If pharmacist considered an interaction or an intervention clinically relevant, the oncologist was notified. Then, a literature review was realized to identify the potential HDI (no interactions, precautions for use, contraindication). Among 201 pharmacist counseling sessions, it resulted in 104 interventions related to 46 HDI, 28 drug-drug interactions and 30 others (wrong dosage, omission…). To determine HDI, we review 73 medicinal plants which are used by our patients with cancer and 31 OAA. A total of 1829 recommendations were formulated about 59 (75%) medical plants and their interaction with an OAA. Herb-drug interactions should not be ignored by healthcare providers in their management of cancer patients in daily practice.

Synergistic antitumor activity of low-dose c-Met tyrosine kinase inhibitor and sorafenib on human non-small cell lung cancer cells

Sorafenib is a multikinase inhibitor that is frequently used to treat various types of malignant tumors. However, it has been demonstrated that Sorafenib only has a moderate antitumor efficacy and is associated with numerous side effects in non-small cell lung cancer (NSCLC), which greatly limits its clinical application. The present study aimed to examine the effects of a combination of Sorafenib and low-dose PF-2341066, a selective c-Met tyrosine kinase inhibitor, on the proliferation, apoptosis and migration of the NSCLC cell line NCI-H1993. The data indicated that treatment with a combination of Sorafenib and low-dose PF-2341066 was able to significantly inhibit the proliferation and migration as well as promote the apoptosis, of NCI-H1993 cells, compared with treatment with Sorafenib or low-dose PF-2341066 alone. Further experiments indicated that the levels of phosphorylated epidermal growth factor receptor and c-Met were significantly decreased following the combined treatment of Sorafenib and PF-2341066, compared with the treatment with Sorafenib or PF-2341066 alone. The findings of the present study indicated that using a low-dose c-Met inhibitor enhances the antitumor activity of Sorafenib in NSCLC and may provide a novel strategy for the treatment of NSCLC.