Host cell environments and antibiotic efficacy in tuberculosis

The aetiologic agent of tuberculosis (TB), Mycobacterium tuberculosis (Mtb), can survive, persist, and proliferate in a variety of heterogeneous subcellular compartments. Therefore, TB chemotherapy requires antibiotics crossing multiple biological membranes to reach distinct subcellular compartments and target these bacterial populations. These compartments are also dynamic, and our understanding of intracellular pharmacokinetics (PK) often represents a challenge for antitubercular drug development. In recent years, the development of high-resolution imaging approaches in the context of host-pathogen interactions has revealed the intracellular distribution of antibiotics at a new level, yielding discoveries with important clinical implications. In this review, we describe the current knowledge regarding cellular PK of antibiotics and the complexity of drug distribution within the context of TB. We also discuss the recent advances in quantitative imaging and highlight their applications for drug development in the context of how intracellular environments and microbial localisation affect TB treatment efficacy.

Exploring the complex relationship between vitamin K, gut microbiota, and warfarin variability in cardiac surgery patients

BACKGROUND AND OBJECTIVES

Due to the high individual variability of anticoagulant warfarin, this study aimed to investigate the effects of vitamin K concentration and gut microbiota on individual variability of warfarin in 246 cardiac surgery patients.

METHODS

The pharmacokinetics and pharmacodynamics (PKPD) model predicted international normalized ratio (INR) and warfarin concentration. Serum and fecal samples were collected to detect warfarin and vitamin K [VK1 and menaquinone-4 (MK4)] concentrations and gut microbiota diversity, respectively. In addition, the patient's medical records were reviewed for demographic characteristics, drug history, and CYP2C9, VKORC1, and CYP4F2 genotypes.

RESULTS

The PKPD model predicted ideal values of 62.7% for S-warfarin, 70.4% for R-warfarin, and 76.4% for INR. The normal VK1 level was 1.34±1.12 nmol/ml (95% CI: 0.33-4.08 nmol/ml), and the normal MK4 level was 0.22±0.18 nmol/ml (95% CI: 0.07-0.63 nmol/ml). The MK4 to total vitamin K ratio was 16.5±9.8% (95% CI: 4.3-41.5%). The S-warfarin concentration of producing 50% of maximum anticoagulation and the half-life of prothrombin complex activity tended to increase with vitamin K. Further, Prevotella and Eubacterium of gut microbiota identified as the main bacteria associated with individual variability of warfarin. The results suggest that an increase in vitamin K concentration can decrease anticoagulation, and gut microbiota may influence warfarin anticoagulation through vitamin K2 synthesis.

CONCLUSION

This study highlights the importance of considering vitamin K concentration and gut microbiota when prescribing warfarin. The findings may have significant implications for the personalized use of warfarin. Further research is needed to understand better the role of vitamin K and gut microbiota in warfarin anticoagulation.

Beta-Lactam Dose Optimisation in the Intensive Care Unit: Targets, Therapeutic Drug Monitoring and Toxicity

Beta-lactams are an important family of antibiotics used to treat infections and are commonly used in critically ill patients. Optimal use of these drugs in the intensive care unit (ICU) is important because of the serious complications from sepsis. Target beta-lactam antibiotic exposures may be chosen using fundamental principles of beta-lactam activity derived from pre-clinical and clinical studies, although the debate regarding optimal beta-lactam exposure targets is ongoing. Attainment of target exposures in the ICU requires overcoming significant pharmacokinetic (PK) and pharmacodynamic (PD) challenges. For beta-lactam drugs, the use of therapeutic drug monitoring (TDM) to confirm if the desired exposure targets are achieved has shown promise, but further data are required to determine if improvement in infection-related outcomes can be achieved. Additionally, beta-lactam TDM may be useful where a relationship exists between supratherapeutic antibiotic exposure and drug adverse effects. An ideal beta-lactam TDM service should endeavor to efficiently sample and report results in identified at-risk patients in a timely manner. Consensus beta-lactam PK/PD targets associated with optimal patient outcomes are lacking and should be a focus for future research.

Exhaustive in silico design and screening of novel antipsychotic compounds with improved pharmacodynamics and blood-brain barrier permeation properties

Antipsychotic drugs or neuroleptics are widely used in the treatment of psychosis as a manifestation of schizophrenia and bipolar disorder. However, their effectiveness largely depends on the blood-brain barrier (BBB) permeation (pharmacokinetics) and drug-receptor pharmacodynamics. Therefore, in this study, we developed and implemented the in silico pipeline to design novel compounds (n = 260) as leads using the standard drug scaffolds with improved PK/PD properties from the standard scaffolds. As a result, the best candidates (n = 3) were evaluated in molecular docking to interact with serotonin and dopamine receptors. Finally, haloperidol (HAL) derivative (1-(4-fluorophenyl)-4-(4-hydroxy-4-{4-[(2-phenyl-1,3-thiazol-4-yl)methyl]phenyl}piperidin-1-yl)butan-1-one) was identified as a "magic shotgun" lead compound with better affinity to the 5-HT2A, 5-HT1D, D2, D3, and 5-HT1B receptors than the control molecule. Additionally, this hit substance was predicted to possess similar BBB permeation properties and much lower toxicological profiles in comparison to HAL. Overall, the proposed rational drug design platform for novel antipsychotic drugs based on the BBB permeation and receptor binding might be an invaluable asset for a medicinal chemist or translational pharmacologist.Communicated by Ramaswamy H. Sarma.

Pharmacokinetics and Pharmacodynamics of a Novel Vancomycin Derivative LYSC98 in a Murine Thigh Infection Model Against Staphylococcus aureus

Introduction

LYSC98 is a novel vancomycin derivative used for gram-positive bacterial infections. Here we compared the antibacterial activity of LYSC98 with vancomycin and linezolid in vitro and in vivo. Besides, we also reported the pharmacokinetic/pharmacodynamic (PK/PD) index and efficacy-target values of LYSC98.

Methods

The MIC values of LYSC98 were identified through broth microdilution method. A mice sepsis model was established to investigate the protective effect of LYSC98 in vivo. Single-dose pharmacokinetics of LYSC98 was studied in thigh-infected mice and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to determine LYSC98 concentration in plasma. Dose fractionation studies were performed to evaluate different PK/PD indices. Two methicillin-resistant Staphylococcus aureus (MRSA) clinical strains were used in the dose ranging studies to determine the efficacy-target values.

Results

LYSC98 showed a universal antibacterial effect in Staphylococcus aureus with a MIC range of 2-4 µg/mL. In vivo, LYSC98 demonstrated distinctive mortality protection in mice sepsis model with an ED₅₀ value of 0.41-1.86 mg/kg. The pharmacokinetics results displayed maximum plasma concentration (C_max) 11,466.67-48,866.67 ng/mL, area under the concentration-time curve from 0 to 24 h (AUC_0-24) 14,788.42-91,885.93 ng/mL·h, and elimination half-life (T_1/2) 1.70-2.64 h, respectively. C_max/MIC (R ² 0.8941) was proved to be the most suitable PK/PD index for LYSC98 to predict its antibacterial efficacy. The magnitude of LYSC98 C_max/MIC associated with net stasis, 1, 2, 3 and 4 - log ₁₀ kill were 5.78, 8.17, 11.14, 15.85 and 30.58, respectively.

Conclusion

Our study demonstrates that LYSC98 is more effective than vancomycin either in killing vancomycin-resistant Staphylococcus aureus (VRSA) in vitro or treating S. aureus infections in vivo, making it a novel and promising antibiotic. The PK/PD analysis will also contribute to the LYSC98 Phase I dose design.

Vancomycin dosing in patients with obesity

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

Systems model identifies baseline cytokine concentrations as potential predictors of rheumatoid arthritis inflammatory response to biologics

BACKGROUND AND PURPOSE

Circulating cytokines are central pathological mediators of inflammatory autoimmune diseases like rheumatoid arthritis (RA). Immunological diversity in patients might contribute to inadequate responses to biological drugs. To address this therapeutic challenge, we developed a mathematical model that simultaneously describes temporal patterns of drug disposition for several biologics and their corresponding targeted cytokines, which were linked to triggering inflammatory responses.

EXPERIMENTAL APPROACH

A modeling framework was applied to RA-relevant cytokines regulating C-reactive protein (CRP) as an inflammatory marker. Clinical data were extracted from the literature for anakinra, canakinumab, infliximab, secukinumab, and tocilizumab, along with their corresponding cytokines: interleukin-1 receptor antagonist, IL-1β, tumor necrosis factor α (TNFα), IL-17A, and IL-6 receptor (IL-6R). Based on prior knowledge of regulatory mechanisms, cytokines were integrated with CRP profiles.

KEY RESULTS

The model well captured all serum concentration-time profiles of cytokines and CRP ratios to respective baselines following drug treatment with good precision. On external validation, reasonable model-performance on CRP dynamics, including rebound effects, was confirmed with clinical data not used in model development. Model-based simulations demonstrated that serum infliximab concentrations were accurately recapitulated in both a dose- and baseline TNFα-dependent manner. Furthermore, high baseline profiles of both IL-1β and/or targeted cytokines could be predictors of poor responses to biologics targeting TNFα and IL-6R, although the impact of IL-1β must be carefully interpreted.

CONCLUSIONS AND IMPLICATION

Our model provides a quantitative platform to guide targeting and dosing strategies, including combination and/or sequential therapy, according to distinct baseline cytokine patterns in RA patients.

Translational Modeling Identifies Synergy between Nanoparticle-Delivered miRNA-22 and Standard-of-Care Drugs in Triple-Negative Breast Cancer

Purpose

Downregulation of miRNA-22 in triple-negative breast cancer (TNBC) is associated with upregulation of eukaryotic elongation 2 factor kinase (eEF2K) protein, which regulates tumor growth, chemoresistance, and tumor immunosurveillance. Moreover, exogenous administration of miRNA-22, loaded in nanoparticles to prevent degradation and improve tumor delivery (termed miRNA-22 nanotherapy), to suppress eEF2K production has shown potential as an investigational therapeutic agent in vivo.

Methods

To evaluate the translational potential of miRNA-22 nanotherapy, we developed a multiscale mechanistic model, calibrated to published in vivo data and extrapolated to the human scale, to describe and quantify the pharmacokinetics and pharmacodynamics of miRNA-22 in virtual patient populations.

Results

Our analysis revealed the dose-response relationship, suggested optimal treatment frequency for miRNA-22 nanotherapy, and highlighted key determinants of therapy response, from which combination with immune checkpoint inhibitors was identified as a candidate strategy for improving treatment outcomes. More importantly, drug synergy was identified between miRNA-22 and standard-of-care drugs against TNBC, providing a basis for rational therapeutic combinations for improved response

Conclusions

The present study highlights the translational potential of miRNA-22 nanotherapy for TNBC in combination with standard-of-care drugs. 

Supplementary Information

The online version contains supplementary material available at 10.1007/s11095-022-03176-3.

Single Oral Doses of MK-8507, a Novel Non-Nucleoside Reverse Transcriptase Inhibitor, Suppress HIV-1 RNA for a Week

BACKGROUND

MK-8507 is a novel HIV-1 non-nucleoside reverse transcriptase inhibitor being developed for treatment of HIV-1 infection. MK-8507 has high antiviral potency in vitro and pharmacokinetic (PK) properties that support once-weekly dosing.

SETTING

A phase 1, open-label, proof-of-concept study was conducted in treatment-naive adults with HIV-1 infection to assess monotherapy antiviral activity.

METHODS

In 3 sequential panels, participants aged 18-60 years with baseline plasma HIV-1 RNA ≥10,000 copies/mL and CD4+ T-cell count >200/mm3 received a single oral dose of 40, 80, or 600 mg MK-8507 in the fasted state. Participants were assessed for HIV-1 RNA for at least 7 days, PKs for 14 days, and safety and tolerability for 21 days postdose.

RESULTS

A total of 18 participants were enrolled (6 per panel). The mean 7-day postdose HIV-1 RNA reduction ranged from ∼1.2 to ∼1.5 log10 copies/mL across the doses assessed. One patient had a viral rebound associated with emergence of an F227C reverse transcriptase variant (per chain-termination method sequencing) 14 days postdose; this variant was found in a second participant by ultra-deep sequencing as an emerging minority variant. MK-8507 PKs were generally dose-proportional and similar to observations in participants without HIV-1 infection in prior studies; mean MK-8507 half life was 56-69 hours in this study. MK-8507 was generally well tolerated at all doses.

CONCLUSIONS

The robust antiviral activity, PK, and tolerability of MK-8507 support its continued development as part of a complete once weekly oral regimen for HIV-1 treatment; combination therapy could mitigate the emergence of resistance-associated variants.

Re-Assessing PK/PD Issues for Oral Protein and Peptide Delivery

Due to a lack of safe and effective oral delivery strategies for most protein and peptide therapeutics, pharmaceutical drug developers have focused on parenteral routes to administer these agents. Recent advances in delivery technologies have now shown clinical validation for a few of these biopharmaceuticals following oral administration. While these initial opportunities have provided more than just a glimmer of hope within the industry, there are important aspects of oral biopharmaceutical delivery that do not completely align with pharmacokinetic (PK) parameters and pharmacodynamics (PD) outcomes that have been learned from parenteral administrations. This commentary examines some of these issues with the goal of presenting a rationale for re-assessing methods, models, and success criteria to better measure oral protein or peptide delivery outcomes related to PK/PD events.

Antimicrobial Peptides: A New Hope in Biomedical and Pharmaceutical Fields

Antibiotics are essential drugs used to treat pathogenic bacteria, but their prolonged use contributes to the development and spread of drug-resistant microorganisms. Antibiotic resistance is a serious challenge and has led to the need for new alternative molecules less prone to bacterial resistance. Antimicrobial peptides (AMPs) have aroused great interest as potential next-generation antibiotics, since they are bioactive small proteins, naturally produced by all living organisms, and representing the first line of defense against fungi, viruses and bacteria. AMPs are commonly classified according to their sources, which are represented by microorganisms, plants and animals, as well as to their secondary structure, their biosynthesis and their mechanism of action. They find application in different fields such as agriculture, food industry and medicine, on which we focused our attention in this review. Particularly, we examined AMP potential applicability in wound healing, skin infections and metabolic syndrome, considering their ability to act as potential Angiotensin-Converting Enzyme I and pancreatic lipase inhibitory peptides as well as antioxidant peptides. Moreover, we argued about the pharmacokinetic and pharmacodynamic approaches to develop new antibiotics, the drug development strategies and the formulation approaches which need to be taken into account in developing clinically suitable AMP applications.

Therapeutic Monitoring of Vancomycin for Serious Methicillin-resistant Staphylococcus aureus Infections: A Revised Consensus Guideline and Review by the American Society of Health-system Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists

Recent clinical data on vancomycin pharmacokinetics and pharmacodynamics suggest a reevaluation of current dosing and monitoring recommendations. The previous 2009 vancomycin consensus guidelines recommend trough monitoring as a surrogate marker for the target area under the curve over 24 hours to minimum inhibitory concentration (AUC/MIC). However, recent data suggest that trough monitoring is associated with higher nephrotoxicity. This document is an executive summary of the new vancomycin consensus guidelines for vancomycin dosing and monitoring. It was developed by the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists vancomycin consensus guidelines committee. These consensus guidelines recommend an AUC/MIC ratio of 400-600 mg*hour/L (assuming a broth microdilution MIC of 1 mg/L) to achieve clinical efficacy and ensure safety for patients being treated for serious methicillin-resistant Staphylococcus aureus infections.

Pharmacokinetic-Pharmacodynamic Modeling of Tumor Targeted Drug Delivery Using Nano-Engineered Mesenchymal Stem Cells

Nano-engineered mesenchymal stem cells (nano-MSCs) are promising targeted drug delivery platforms for treating solid tumors. MSCs engineered with paclitaxel (PTX) loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) are efficacious in treating lung and ovarian tumors in mouse models. The quantitative description of pharmacokinetics (PK) and pharmacodynamics (PD) of nano-MSCs is crucial for optimizing their therapeutic efficacy and clinical translatability. However, successful translation of nano-MSCs is challenging due to their complex composition and physiological mechanisms regulating their pharmacokinetic-pharmacodynamic relationship (PK-PD). Therefore, in this study, a mechanism-based preclinical PK-PD model was developed to characterize the PK-PD relationship of nano-MSCs in orthotopic A549 human lung tumors in SCID Beige mice. The developed model leveraged literature information on diffusivity and permeability of PTX and PLGA NPs, PTX release from PLGA NPs, exocytosis of NPs from MSCs as well as PK and PD profiles of nano-MSCs from previous in vitro and in vivo studies. The developed PK-PD model closely captured the reported tumor growth in animals receiving no treatment, PTX solution, PTX-PLGA NPs and nano-MSCs. Model simulations suggest that increasing the dosage of nano-MSCs and/or reducing the rate of PTX-PLGA NPs exocytosis from MSCs could result in improved anti-tumor efficacy in preclinical settings.

Pharmacokinetics, pharmacodynamics and tolerability of single and multiple doses of janagliflozin, a sodium-glucose co-transporter-2 inhibitor, in Chinese people with type 2 diabetes mellitus

AIMS

To evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics, and tolerability of janagliflozin, a novel sodium-glucose co-transporter-2 inhibitor, in Chinese people with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

In this study, 36 people with T2DM were randomly assigned in a 1:1:1:1 ratio to receive janagliflozin 25 mg, janagliflozin 50 mg, dapagliflozin 10 mg or placebo. Participants received a single dose on day 1, and were treated once daily from day 4 to day 17.

RESULTS

Following oral administration, janagliflozin was rapidly absorbed, reaching C_max at 2 hours. The mean half-life (t_1/2 ) at steady state was approximately 21 to 23 hours. There was no significant accumulation with multiple doses (accumulation factor < 2). In participants treated with janagliflozin 25 mg, janagliflozin 50 mg, dapagliflozin 10 mg or placebo, change in mean 24-hour urinary glucose excretion from baseline was 92.35, 94.17, 87.61 and 6.26 g after multiple doses, and change in mean fasting plasma glucose level from baseline to day 17 was -2.18, -2.66, -2.79 and 1.70%, respectively. Most adverse events (AEs) were mild or moderate with no deaths, serious AEs, or discontinuations due to AEs.

CONCLUSIONS

Single and multiple oral administration (14 days) of janagliflozin 25 mg and 50 mg exhibited favourable PK, PD and tolerability profiles in Chinese people with T2DM, which were comparable to those of dapagliflozin 10 mg. Janagliflozin 25 mg and 50 mg are recommended for further clinical investigation.

Determinants of omalizumab dose-related efficacy in oral immunotherapy: Evidence from a cohort of 181 patients

BACKGROUND

Omalizumab has been shown to improve the safety and feasibility of oral immunotherapy (OIT), but the optimal dosage strategy is unknown.

OBJECTIVE

Our aim was to identify determinants of omalizumab dose-related efficacy in the context of OIT.

METHODS

The study sample consisted of a clinical cohort of 181 patients treated with omalizumab-enabled oral immunotherapy at 3 centers. Patients received omalizumab for at least 2 months before an initial food escalation (IFE) with a mix of up to 6 allergens. Progression through IFE steps was assessed with survival analysis. Continued food dose tolerance with omalizumab weaning was also documented.

RESULTS

Omalizumab dosage per weight alone was strongly associated with progression through the IFE (χ² = 28.18; P < .0001), whereas the standard dosage per weight and total IgE level used for asthma was not (χ² = 0.001; P = .97). When the values at time of IFE were estimated through pharmacokinetics and pharmacodynamics simulation, IFE outcome was best predicted by a model that includes levels of free allergen-specific IgE and their interaction with blocking omalizumab-IgE complexes and free omalizumab levels in serum (χ² = 65.84; degrees of freedom [df] = 2; P < .0005). The occurrence of immediate-type reactions to food dosing subsequent to weaning of omalizumab was associated with a greater ratio of specific IgE level to total IgE level at baseline (geometric mean 0.39 vs 0.16 in those without symptom; P < .0001).

CONCLUSION

In the context of OIT and IgE-mediated disease, omalizumab dosages should be adjusted for body weight alone, independently of total IgE level. The fraction of allergen-specific/total IgE may be useful to predict patients at greater risk of food dosing reactions subsequent to weaning.

Executive Summary: Therapeutic Monitoring of Vancomycin for Serious Methicillin-Resistant Staphylococcus aureus Infections: A Revised Consensus Guideline and Review of the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists

BACKGROUND

Recent vancomycin PK/PD and toxicodynamic studies enable a reassessment of the current dosing and monitoring guideline in an attempt to further optimize the efficacy and safety of vancomycin therapy. The area-under-the-curve to minimum inhibitory concentration (AUC/MIC) has been identified as the most appropriate pharmacokinetic/pharmacodynamic (PK/PD) target for vancomycin. The 2009 vancomycin consenus guidelines recommended specific trough concentrations as a surrogate marker for AUC/MIC. However, more recent toxicodynamic studies have reported an increase in nephrotoxicity associated with trough monitoring.

METHODS AND RESULTS

This is the executive summary of the new vancomycin consensus guidelines for dosing and monitoring vancomycin therapy and was developed by the American Society of Health-Systems Pharmacists, Infectious Diseases Society of America, Pediatric Infectious Diseases Society and the Society of Infectious Diseases Pharmacists vancomycin consensus guidelines committee.

CONCLUSIONS

The recommendations provided in this document are intended to assist the clinician in optimizing vancomycin for the treatment of invasive MRSA infections in adult and pediatric patients. An AUC/MIC by broth microdilution (BMD) ratio of 400 to 600 (assuming MICBMD of 1 mg/L) should be advocated as the target to achieve clinical efficacy while improving patient safety for patients with serious MRSA infections. In such cases, AUC-guided dosing and monitoring is the most accurate and optimal way to manage vancomycin therapy.

The Pre-clinical Toolbox of Pharmacokinetics and Pharmacodynamics: in vitro and ex vivo Models

Prevention strategies against sexual transmission of human immunodeficiency virus (HIV) are essential to curb the rate of new infections. In the absence of a correlate of protection against HIV infection, pre-clinical evaluation is fundamental to facilitate and accelerate prioritization of prevention candidates and their formulations in a rapidly evolving clinical landscape. Characterization of pharmacokinetic (PK) and pharmacodynamic (PD) properties for candidate inhibitors is the main objective of pre-clinical evaluation. in vitro and ex vivo systems for pharmacological assessment allow experimental flexibility and adaptability at a relatively low cost without raising as significant ethical concerns as in vivo models. Applications and limitations of pre-clinical PK/PD models and future alternatives are reviewed in the context of HIV prevention.

Pharmacokinetics and pharmacodynamics of oral anticoagulants used in atrial fibrillation

INTRODUCTION

The availability of non-vitamin K antagonist oral anti-coagulants alongside vitamin K antagonists has offered a variety of options for anti-coagulation, but has also necessitated a good understanding of the pharmacological properties of each of these drugs prior to their use, to maximise the therapeutic benefit and minimise patient harm Areas covered: This review article outlines the pharmacokinetic and pharmacodynamic profiles of the currently licensed VKAs and NOACs that are most commonly used in clinical practice, with the aim of demonstrating how variations in these characteristics influence their use in clinical practice. A literature search was conducted on PubMed using keywords and relevant articles published by the 31^st of December 2018 were included. Expert opinion: The effect of a drug is determined by a combination of elements which include patient characteristics and external factors, in addition to its pharmacokinetic and pharmacodynamic properties. A good understanding of these is essential. Despite the wealth of information available, particularly on VKAs, our knowledge on the pharmacology responsible for certain drug effects and inter-individual variations is still limited. Increasing efforts are being made to understand these and include focus on pharmacogenomics and drug transporter proteins.

Influence of Renal Function on Evolocumab Exposure, Pharmacodynamics, and Safety

We evaluated the pharmacokinetics, pharmacodynamics, and safety of evolocumab, a fully human monoclonal antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), in an open‐label, parallel‐design study in participants with normal renal function (n = 6), severe renal impairment (RI; n = 6), or end‐stage renal disease (ESRD) receiving hemodialysis (n = 6) who received a single 140‐mg dose of evolocumab. The effects of evolocumab treatment on low‐density lipoprotein cholesterol (LDL‐C) lowering and unbound PCSK9 concentrations were similar in the normal renal function group and the renally impaired groups. Geometric mean C_max and AUC_last values in the severe RI and ESRD hemodialysis groups compared with the normal renal function group were lower but within 37% of the normal renal function group (Jonckheere‐Terpstra trend test; C_max, P = .23; AUC_last, P = .22) and within 26% after adjusting for body weight (mean body weight was approximately 9% higher in the renally impaired groups compared with the normal renal function group). No correlations were observed between exposure and baseline creatinine clearance. No adverse event was determined by the investigators to be related to evolocumab, and there were no trends indicative of clinically important effects on laboratory variables or vital signs. Overall, there were no meaningful differences in evolocumab exposure, as assessed by C_max and AUC_last, in patients with severe RI and ESRD hemodialysis compared with patients with normal renal function, and LDL‐C‐lowering effects were similar across groups. These results support the use of evolocumab without dose adjustment in patients who have severe RI or ESRD.

Single cell-produced and in vitro-assembled anti-FcRH5/CD3 T-cell dependent bispecific antibodies have similar in vitro and in vivo properties

Bispecific antibody production using single host cells has been a new advancement in the antibody engineering field. We previously showed comparable in vitro biological activity and in vivo mouse pharmacokinetics (PK) for two novel single cell variants (v10 and v11) and one traditional dual cell in vitro-assembled anti-human epidermal growth factor receptor 2/CD3 T-cell dependent bispecific (TDB) antibodies. Here, we extended our previous work to assess single cell-produced bispecific variants of a novel TDB against FcRH5, a B-cell lineage marker expressed on multiple myeloma (MM) tumor cells. An in vitro-assembled anti- FcRH5/CD3 TDB antibody was previously developed as a potential treatment option for MM. Two bispecific antibody variants (designs v10 and v11) for manufacturing anti-FcRH5/CD3 TDB in single cells were compared to in vitro-assembled TDB in a dual-cell process to understand whether differences in antibody design and production led to any major differences in their in vitro biological activity, in vivo mouse PK, and PK/pharmacodynamics (PD) or immunogenicity in cynomolgus monkeys (cynos). The binding, in vitro potencies, in vitro pharmacological activities and in vivo PK in mice and cynos of these single cell TDBs were comparable to those of the in vitro-assembled TDB. In addition, the single cell and in vitro-assembled TDBs exhibited robust PD activity and comparable immunogenicity in cynos. Overall, these studies demonstrate that single cell-produced and in vitro-assembled anti-FcRH5/CD3 T-cell dependent bispecific antibodies have similar in vitro and in vivo properties, and support further development of single-cell production method for anti-FcRH5/CD3 TDBs and other single-cell bispecifics.

Risk-Based Comparability Assessment for Monoclonal Antibodies During Drug Development: A Clinical Pharmacology Perspective

Due to complexities in the structure, function, and manufacturing process of antibody-based therapeutic proteins, comparability assessment for supporting manufacturing changes can sometimes be a challenging task. Regulatory guidance recommends a hierarchical risk-based approach, starting with Chemistry, Manufacturing, and Controls (CMC) analytical characterizations, followed by non-clinical and/or clinical studies to ensure that any potential changes in quality attributes have no adverse impact on efficacy and safety of the product. This review focuses on the changes in quality attributes which may potentially affect the pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of a monoclonal antibody (mAb) product, and provides general guidelines in designing non-clinical and clinical PK/PD studies to help support comparability assessments. A decision tree for comparability assessment is proposed depending on the nature of the changes in quality attributes, the potential impact of such changes, and the timing of the manufacturing change relative to the development process. Ideally, the optimization of manufacturing process should take place in the early stage of drug development (i.e., preclinical to phase 2a) as more stringent comparability criteria would have to be met if manufacturing changes occur in the late stage of drug development (i.e., phase 2b and after), and consequently, major changes in manufacturing process should be avoided during confirmatory phase 3 studies and post-approval of drug products.

Tamibarotene-Loaded PLGA Microspheres for Intratumoral Injection Administration: Preparation and Evaluation

Tamibarotene (Am80) has good curative effect on advanced hepatocellular carcinoma (HCC). To improve the therapeutic efficacy furtherly, we prepared tamibarotene-loaded PLGA microspheres (Am80-PLGA-MS) for intratumoral injection. Firstly, Am80-PLGA-MS were prepared by emulsion-solvent evaporation method. Subsequently, microspheres were characterized by particle size analysis, drug loading (DL), and entrapment efficiency (EE). Finally, the drug release characteristics in vitro, pharmacokinetic, and pharmacodynamics were studied separately. According to results obtained, microspheres were spherical with a uniform particle size 7.04 ± 0.03 μm and its EE and DL were 82.23 ± 0.74 and 11.74 ± 0.11%, respectively. In vitro, Am80-PLGA-MS can release drug for 14 days and its release behavior was fitted with the Higuchi equation. In pharmacokinetic studies, the t1/2β, MRT, and AUC of microspheres were 15.43-fold, 8.62-fold, and 9.98-fold those of Am80 solution, respectively, which revealed that the utilization of drug was improved obviously. The pharmacodynamics studies showed that the tumor doubling time, growth inhibition rate, and specific growth rate of tumor of Am80-PLGA-MS were 1.34 times, 2.63 times, and 0.72 times those of drug solution, respectively, indicating that the inhibitory effect on tumor by the microspheres was significantly improved. In summary, Am80-PLGA-MS are promising carrier to enhance the inhibitory effect on tumor, which will provide significantly clinical value for treatment of HCC.

A phase I study of intravenous and oral rucaparib in combination with chemotherapy in patients with advanced solid tumours

BACKGROUND

This study evaluated safety, pharmacokinetics, and clinical activity of intravenous and oral rucaparib, a poly(ADP-ribose) polymerase inhibitor, combined with chemotherapy in patients with advanced solid tumours.

METHODS

Initially, patients received escalating doses of intravenous rucaparib combined with carboplatin, carboplatin/paclitaxel, cisplatin/pemetrexed, or epirubicin/cyclophosphamide. Subsequently, the study was amended to focus on oral rucaparib (once daily, days 1-14) combined with carboplatin (day 1) in 21-day cycles. Dose-limiting toxicities (DLTs) were assessed in cycle 1 and safety in all cycles.

RESULTS

Eighty-five patients were enrolled (22 breast, 15 ovarian/peritoneal, and 48 other primary cancers), with a median of three prior therapies (range, 1-7). Neutropenia (27.1%) and thrombocytopenia (18.8%) were the most common grade ⩾3 toxicities across combinations and were DLTs with the oral rucaparib/carboplatin combination. Maximum tolerated dose for the combination was 240 mg per day oral rucaparib and carboplatin area under the curve 5 mg ml-1 min-1. Oral rucaparib demonstrated dose-proportional kinetics, a long half-life (≈17 h), and good bioavailability (36%). Pharmacokinetics were unchanged by carboplatin coadministration. The rucaparib/carboplatin combination had radiologic antitumour activity, primarily in BRCA1- or BRCA2-mutated breast and ovarian/peritoneal cancers.

CONCLUSIONS

Oral rucaparib can be safely combined with a clinically relevant dose of carboplatin in patients with advanced solid tumours (Trial registration ID: NCT01009190).

Development of transmucosal patch loaded with anesthetic and analgesic for dental procedures and in vivo evaluation

Most of the dental surgeries require preoperative anesthetic and postoperative analgesic for painless procedures. A multidrug transmucosal drug delivery system loaded with lignocaine (Lig) base for immediate release and solid lipid nanoparticles (SLNs) of diclofenac (Dic) diethylamine for prolonged release was developed. SLNs were prepared by solvent emulsion-evaporation method with Precirol ATO 5 and Geleol as lipids and Pluronic F 68 as surfactant and optimized with Box-Behnken design for particle size and entrapment efficiency. SLNs were incorporated into the transmucosal patch (TP) prepared with hydroxypropyl cellulose-LF (HPC-LF) and with a backing layer of ethyl cellulose. Optimized SLNs and TP were characterized for Fourier transform infrared spectrophotometry, differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, in vitro release, ex vivo permeation through porcine buccal mucosa, Caco-2 permeability, and residual solvent analysis by gas chromatography. The TP was also evaluated for swelling index, in vitro residence time, tensile strength, and mucoadhesive strength. Preclinical pharmacokinetic, pharmacodynamic, and histopathological studies by application of TP on the gingiva of New Zealand rabbits were carried out. Particle size and entrapment efficiency of the optimized SLN "S8" were determined as 98.23 nm and 84.36%, respectively. The gingival crevicular fluid and tissue concentrations were greater than plasma concentrations with increase in C max and area under the curve (AUC) of Lig and Dic when compared to the control group. Pain perception by needle prick showed prolonged combined anesthetic and analgesic effect. The developed TP loaded with Lig base and Dic diethylamine-SLNs exhibited immediate and complete permeation with tissue accumulation of Lig followed by controlled prolonged release and tissue accumulation of Dic at the site of application. Thus, it could be anticipated from the in vivo studies that the developed TP provides immediate initial anesthetic effect, and the analgesic effect would be prolonged for 24 hours, since optimal gingival crevicular fluid and tissue levels of analgesic would be achieved, while the tissue remains anesthetized.

Polymyxin B versus colistin: an update

Polymyxin B and colistin (polymyxin E) are polypeptide antibiotics that were developed in the 1940s, but fell into disfavor due to their high toxicity rates. These two antibiotics were previously regarded to be largely equivalent, due to similarities in their chemical structure and spectrum of activity. In recent years, several pertinent differences, especially in terms of potency and disposition, have been revealed between polymyxin B and colistin. These differences are mainly attributed to the fact that polymyxin B is administered parenterally in its active form, while colistin is administered parenterally as an inactive pro-drug, colistimethate. In this review, we summarize the similarities and differences between polymyxin B and colistin. We also discuss the potential clinical implications of these findings, and provide our perspectives on how polymyxins should be employed to preserve their utility in this era of multi-drug resistance.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Vilanterol, a Novel Inhaled Long-Acting β-Agonist, in Children Aged 5-11 Years with Persistent Asthma: A Randomized Trial

This multi-center, randomized, double-blind, placebo-controlled, two-way crossover study was designed to characterize the safety, tolerability, pharmacokinetic, and pharmacodynamic profile of single and once-daily repeat doses of vilanterol 25 µg in children aged 5–11 years. Twenty-eight children with persistent asthma received a single inhaled dose of vilanterol 25 µg or placebo via the ELLIPTA™ dry powder inhaler (DPI) on Day 1, followed 7 days later by once-daily treatment for 7 days. Nine (33%) subjects reported adverse events (AEs) with vilanterol 25 µg and 6 (23%) with placebo. No serious or drug-related AEs were reported; 3 subjects experienced upper respiratory tract infection (URTI) with vilanterol 25 µg versus none with placebo. Similar pharmacokinetic profiles of vilanterol 25 µg were observed irrespective of age or gender. No clinically relevant changes in heart rate, Fridericia's correction (QTcF), maximum glucose or minimum potassium parameters were observed during treatment with vilanterol 25 µg compared with placebo treatment. Vilanterol was well-tolerated and no long-acting ß₂-agonist (LABA)-mediated AEs were observed. The pharmacokinetic profile of vilanterol 25 µg suggests exposure is similar regardless of age or gender in a pediatric population aged 5–11 years.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of fluticasone furoate, a novel inhaled corticosteroid, in children aged 5-11 years with persistent asthma: A randomized trial

This multi-center, randomized, double-blind, placebo-controlled, two-way crossover study characterized the safety, tolerability, pharmacokinetics, and pharmacodynamics of fluticasone furoate (FF) in children (5-11 years) with persistent asthma. Twenty-seven children received inhaled FF 100 µg or placebo via the ELLIPTA™ dry powder inhaler once daily for 14 days, with a ≥7 day washout period. Adverse events (AEs) were reported by eight (31%) and four (16%) subjects during FF 100 µg and placebo treatment, respectively. Headache was reported by three subjects during FF 100 µg treatment and by no subjects during placebo treatment, all other AEs were reported by only one subject on either treatment; there were no serious AEs. Following repeat dosing, the arithmetic mean (SD) FF Cmax was 26.71 pg/mL (9.16) at 31 minutes post-dose. Arithmetic mean (SD) FF AUC(0-t) was 121.44 pg h/mL (83.04). Arithmetic mean values for weighted mean (SD) serum cortisol (0-12 hours) on day 14 were 56.49 (16.51) and 67.57 (20.66) ng/mL for FF 100 µg and placebo, respectively. No clinically significant effect of FF on serum cortisol levels was observed. FF was well tolerated. Pharmacokinetic profiles were well defined and did not differ between age groups in the study population, and no clinically significant suppression of serum cortisol was observed.

Loading regimen required to rapidly achieve therapeutic trough plasma concentration of teicoplanin and evaluation of clinical features

BACKGROUND

A trough concentration of >20 mg/L is considered the optimal dosage of teicoplanin required to ensure early therapeutic effects against methicillin-resistant Staphylococcus aureus (MRSA) infections including those in patients who develop febrile neutropenia after chemotherapy. This study determines appropriate initial doses during the first 2 days of administration and evaluates the therapeutic target teicoplanin trough concentration.

METHOD

A 2-day regimen was evaluated in patients treated with 600 mg and 1200 mg or 1200 mg and 600 mg (total 1800 mg, Group 1), 800 mg and 800 mg (total 1600 mg, Group 2), and 800 mg and 400 mg (total 1200 mg, Group 3) of teicoplanin on Days 1 and 2, respectively. We also compared the efficiency and adverse effects at trough concentrations of 15-20 mg/L (Group A, n = 28) with >20 mg/L (Group B, n = 27) of teicoplanin, and also compared them with those on the similar concentrations of vancomycin (Groups C and D, n = 50 and 34, respectively).

RESULTS

The mean trough concentrations of teicoplanin on Days 4 or 5 were 22.2, 17.5, and 16.2 mg/L in Groups 1, 2, and 3, respectively. The clinical efficiency was 85.7%, 81.5%, 92.0%, and 91.5%, in Groups A, B, C, and D, respectively. The rates of adverse effects were not high in teicoplanin (nephrotoxicity, 7.1% and 3.7%, and hepatotoxicity, 14.3% and 11.1% in Groups A and B, respectively). However, more adverse effects tended to arise in patients who received vancomycin in nephrotoxicity (14.0% and 11.8%, in Groups C and D, respectively).

CONCLUSION

These results suggest that the 2-day regimens with total 1800 mg achieved the most effective therapeutic trough plasma concentration of teicoplanin (20 mg/L). However, 15-20 mg/L might also be an effective trough target for initial teicoplanin treatment. These teicoplanin regimens might be safer in terms of renal function than vancomycin.

Modelling the kinetics of hepatitis C virus RNA decline over 4 weeks of treatment with pegylated interferon alpha-2b

Viral kinetic models for hepatitis C virus (HCV) have generally assumed that the effectiveness of therapy in blocking virion production, epsilon, is constant. However, with pegylated interferon alpha-2b (PEG-IFN) given weekly, there are significant changes in drug concentration between doses that may lead to changes in drug effectiveness and viral rebounds towards the end of the dosing interval. Here we investigate the effects of using a model that assumes a constant effectiveness for studies involving PEG-IFN. We simulated PEG-IFN treatment in a population of 294 computer simulated 'patients', each characterized by a different set of pharmacokinetic and pharmacodynamic parameters. We then sampled the simulated treatment data over 4 weeks with a schedule similar to that used in viral kinetic studies, and fitted a viral kinetic model assuming constant drug effectiveness, the CE model, to that data. Although the CE model was able to fit to the data well in most cases, the parameter estimates obtained scattered widely both above and below the true values. Thus, this model is less useful to analyse HCV RNA data during therapy with PEG-IFN than with standard IFN given daily. With PEG-IFN accurate estimation of viral dynamic parameters necessitates concomitant measurements of serum viral load and drug concentration.

Population analysis of the pharmacokinetics and pharmacodynamics of RWJ-270201 (BCX-1812) in treating experimental influenza A and B virus in healthy volunteers

OBJECTIVE

Our objective was to assess the pharmacokinetics and pharmacodynamics of RWJ-270201 (BCX-1812), an oral neuraminidase inhibitor for the treatment of influenza A and B virus in healthy volunteers.

METHODS

This was a double-blind, randomized, placebo-controlled, parallel group study. A total of 80 adult male and female subjects were enrolled for the influenza A challenge study. This was a 5-arm study (100 mg/qd, 200 mg/qd, 200 mg/bid, 400 mg/qd, and placebo). In the challenge B virus model, 60 subjects were enrolled for a 3-arm study (800 mg on Day 1 followed by 400 mg on Days 2-5; 800 mg on Days 1-5; and placebo). The pharmacokinetics of RWJ-270201 (BCX-1812) were characterized with the use of a population approach and were described by a 2-compartmental model with first-order absorption and elimination. The pharmacodynamic data, mean log viral titers, were described with the use of an empirical equation relating the viral growth and the effect of drug on changes in viral titers.

RESULTS

Pharmacokinetic analyses show that weight was the most significant covariate for all estimated pharmacokinetic parameters. The pharmacodynamic data, mean log viral titers showed a decrease in viral titers with increase in plasma exposure. The decrease in viral titer started to occur 12 hours following the drug dosing, and viral suppression lasted 72 hours to 96 hours. The exposures associated with a 50% decrease in viral titers were 1089 ng-h/mL and 1898 ng-h/mL, respectively.

CONCLUSIONS

A PK/PD model was well utilized to characterize the effect of RWJ-270201 (BCX-1812) on the influenza A and B virus. The results from this model showed that both the loading dose and the standard dose regimens are efficacious against A and B virus. RWJ-270201 (BCX-1812) is under clinical development for the treatment of influenza A and B infections in adult and high-risk populations. It is a potent and selective inhibitor of both influenza A and B virus neuraminidases and inhibits the viral cleavage of sialic acid from cell surface glycoproteins and glycolipids. Consequently, RWJ-270201 (BCX-1812) prevents infection by stopping the release of newly formed virus from the surface of infected cells and preventing viral spread across the mucous lining of the respiratory tract. It therefore represents an attractive agent for antiviral therapy.