Mechanistic Model Describing the Time Course of Humoral Immunity Following Ad26.COV2.S Vaccination in Non-Human Primates.

Mechanistic modeling can be used to describe the time course of vaccine-induced humoral immunity and to identify key biologic drivers in antibody production. We used a six-compartment mechanistic model to describe a 20-week time course of humoral immune responses in 56 non-human primates (NHPs) elicited by vaccination with Ad26.COV2.

Safety, Tolerability, and Pharmacokinetics of JNJ-1802, a Pan-serotype Dengue Direct Antiviral Small Molecule, in a Phase 1, Double-Blind, Randomized, Dose-Escalation Study in Healthy Volunteers.

Background: Dengue is a growing global health threat with no specific antiviral drugs available for treatment or prophylaxis. This first-in-human, double-blind, randomized, placebo-controlled study aimed to examine the safety, tolerability, and pharmacokinetics of increasing single and multiple oral doses of JNJ-1802, a pan-serotype dengue antiviral small molecule.

Methods: Eligible healthy participants (18-55 years of age) were randomized to receive oral JNJ-1802 in fasted conditions as (1) single doses (50-1200 mg; n = 29) or placebo (n = 10); or (2) once-daily doses (50-560 mg for 10 consecutive days or 400 mg for 31 days; n = 38) or placebo (n = 9).

Quantifying Antibody Persistence After a Single Dose of COVID-19 Vaccine Ad26.COV2.S in Humans Using a Mechanistic Modeling and Simulation Approach.

Understanding persistence of humoral immune responses elicited by vaccination against coronavirus disease 2019 (COVID-19) is critical for informing the duration of protection and appropriate booster timing. We developed a mechanistic model to characterize the time course of humoral immune responses in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-seronegative adults after primary vaccination with the Janssen COVID-19 vaccine, Ad26.COV2.

Addressing bedaquiline treatment interruptions in the treatment of drug-resistant TB.

The recommended dosing regimen for bedaquiline (BDQ), consisting of a 2-week loading phase (400 mg/day), followed by a maintenance phase (200 mg three times/week), might pose challenges when treatment is interrupted and needs to be reinitiated. Guidance on BDQ treatment re-initiation is, therefore, needed. This pharmacokinetic-based simulation study aimed to provide recommendations for re-initiating BDQ following treatment interruptions.

Zidovudine and lamivudine reach higher concentrations in ventricular than in lumbar human cerebrospinal fluid.

Objective: For the treatment of HIV-1-related brain disease and for the prevention of the brain becoming a viral reservoir, it is important that antiretroviral agents reach sufficient concentrations in the CNS. To date, human brain pharmacokinetic data are solely derived from lumbar cerebrospinal fluid (CSF) and mostly originate from single samples.

Design: We determined concentrations of antiretroviral drugs in serial samples of ventricular CSF and compared these to the concentrations in serum and lumbar CSF of these patients.

Single- and multiple-dose pharmacokinetics and safety of pimodivir, a novel, non-nucleoside polymerase basic protein 2 subunit inhibitor of the influenza A virus polymerase complex, and interaction with oseltamivir: a Phase 1 open-label study in healthy volunteers.

Aims: The aim of this study was to evaluate the drug-drug interaction between pimodivir, a novel, non-nucleoside polymerase basic protein 2 (PB2) subunit inhibitor of the influenza A virus polymerase complex, and oseltamivir, to assess the feasibility of this combination therapy. Furthermore, single- and multiple-dose pharmacokinetics and safety of pimodivir in healthy volunteers were assessed.

Methods: In Part 1 of this open-label Phase 1 study, healthy volunteers (n = 18) were randomized to one of six cross-over treatment sequences, each comprising administration of oseltamivir 75 mg or pimodivir 600 mg or combination thereof twice daily on Days 1-4, followed by a single morning dose on Day 5.

Pharmacokinetics and Pharmacokinetic/Pharmacodynamic Relationships of Etravirine in HIV-1-Infected, Treatment-Experienced Children and Adolescents in PIANO.

PIANO (NCT00665847) investigated etravirine pharmacokinetics, efficacy, and safety in children and adolescents. Treatment-experienced, HIV-1-infected patients (≥6 to <18 years) received etravirine 5.2 mg/kg twice daily (maximum 200 mg twice daily) plus background antiretrovirals.

Pharmacokinetic interaction between etravirine or rilpivirine and telaprevir in healthy volunteers: A randomized, two-way crossover trial.

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) may require treatment with an HIV non-nucleoside reverse transcriptase inhibitor (NNRTI), for example, rilpivirine or etravirine, and an HCV direct-acting antiviral drug such as telaprevir. In a two-panel, two-way, crossover study, healthy volunteers were randomized to receive etravirine 200 mg twice daily ± telaprevir 750 mg every 8 hours or rilpivirine 25 mg once daily ± telaprevir 750 mg every 8 hours. Pharmacokinetic assessments were conducted for each drug at steady-state when given alone and when coadministered; statistical analyses were least-square means with 90% confidence intervals.

Pharmacokinetics of darunavir after administration of an oral suspension with low-dose ritonavir and with or without food.

This 2-part, phase 1, open-label, randomized, crossover study (NCT00752310) assessed ritonavir-boosted darunavir bioavailability (oral suspension vs. tablets), and steady-state darunavir pharmacokinetics (suspension). Part 1: 20 healthy adults randomly received 3 treatments with a ≥7-day washout between treatments; twice-daily ritonavir (100 mg, days 1-5) with darunavir (600 mg, day 3) as 2 × 300-mg tablets (fed, reference), or 6 mL of a 100-mg/mL suspension (fed or fasted, test).

Bioavailability and bioequivalence of a darunavir 800-mg tablet formulation compared with the 400-mg tablet formulation.

Unlabelled: Once-daily darunavir/ritonavir (800/100 mg), plus other antiretrovirals, is recommended for HIV-1-infected patients. Low therapy adherence is linked with poor outcomes. Pill burden can impact adherence.

Bioequivalence of a darunavir/cobicistat fixed-dose combination tablet versus single agents and food effect in healthy volunteers.

Background: Darunavir requires pharmacokinetic enhancement to increase its bioavailability. Cobicistat is potentially an alternative pharmacokinetic booster to ritonavir. Bioequivalence of a darunavir/cobicistat fixed-dose combination (FDC) versus darunavir and cobicistat co-administered as single agents and the effect of a high-fat meal on the pharmacokinetics of the FDC were evaluated.

Pharmacokinetics and pharmacodynamics of boosted once-daily darunavir.

The ability to dose antiretroviral agents once daily simplifies the often complex therapeutic regimens required for the successful treatment of HIV infection. Thus, once-daily dosing can lead to improved patient adherence to medication and, consequently, sustained virological suppression and reduction in the risk of emergence of drug resistance. Several trials have evaluated once-daily darunavir/ritonavir in combination with other antiretrovirals (ARTEMIS and ODIN trials) or as monotherapy (MONET, MONOI and PROTEA trials) in HIV-1-infected adults.

Bedaquiline: a review of human pharmacokinetics and drug-drug interactions.

Bedaquiline has recently been approved for the treatment of pulmonary multidrug-resistant tuberculosis (TB) as part of combination therapy in adults. It is metabolized primarily by the cytochrome P450 isoenzyme 3A4 (CYP3A4) to a less-active N-monodesmethyl metabolite. Phase I and Phase II studies in healthy subjects and patients with drug-susceptible or multidrug-resistant TB have assessed the pharmacokinetics and drug-drug interaction profile of bedaquiline.

Pharmacokinetics of darunavir in fixed-dose combination with cobicistat compared with coadministration of darunavir and ritonavir as single agents in healthy volunteers.

This study compared the bioavailability of two candidate fixed-dose combinations (FDCs: G003 and G004) of darunavir/cobicistat 800/150 mg with that of darunavir 800 mg and ritonavir 100 mg coadministered as single agents. Short-term safety and tolerability of the FDC formulations were also assessed. This open-label trial included 36 healthy volunteers and assessed steady-state pharmacokinetics of darunavir over 3 randomized, 10-day treatment sequences, under fed conditions.

The effect of rilpivirine on the pharmacokinetics of methadone in HIV-negative volunteers.

Antiretrovirals may influence methadone exposure in HIV-1-infected patients receiving methadone for opiate addiction. Rilpivirine is a non-nucleoside reverse transcriptase inhibitor for treating HIV-1 infection. In this open-label trial (NCT00744770), 13 HIV-negative volunteers continued on their regular stable methadone therapy (60 to 100 mg once daily; Days -14 to 12), with rilpivirine coadministration (Days 1 to 11).

The effect of single- and multiple-dose etravirine on a drug cocktail of representative cytochrome P450 probes and digoxin in healthy subjects.

The effect of etravirine on cytochrome P450 (CYP) enzymes and P-glycoprotein were evaluated in two randomized, crossover trials in healthy subjects. A modified Cooperstown 5 + 1 cocktail was utilized to determine the effects of etravirine on single-dose pharmacokinetics of model CYP probes. The cocktail was administered alone, then, after a 14-day washout, etravirine 200 mg twice daily (bid) was given for 14 days with cocktail on days 1 and 14.

Lack of an effect of rilpivirine on the pharmacokinetics of ethinylestradiol and norethindrone in healthy volunteers.

Unlabelled: Rilpivirine is a human immunodeficiency virus Type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitor.

Objective: Rilpivirine metabolism involves cytochrome P450 3A4 (CYP3A4). This trial (ClinicalTrials.

Pharmacokinetic evaluation of the interaction between etravirine and rifabutin or clarithromycin in HIV-negative, healthy volunteers: results from two Phase 1 studies.

Objectives: Drug-drug interactions between etravirine and rifabutin or clarithromycin were examined in two separate open-label, randomized, two-period, crossover trials in HIV-negative, healthy volunteers.

Methods: Rifabutin study: 16 participants received 300 mg of rifabutin once daily (14 days) and then 800 mg of etravirine twice daily (Phase 2 formulation; 21 days) plus 300 mg of rifabutin once daily (days 8-21). Clarithromycin study: 16 participants received 200 mg of etravirine twice daily (commercial formulation; 8 days) and then 500 mg of clarithromycin twice daily (13 days) plus 200 mg of etravirine twice daily (days 6-13).

Safety and pharmacokinetics of the HIV-1 protease inhibitor TMC310911 coadministered with ritonavir in healthy participants: results from 2 phase 1 studies.

Objectives: To evaluate safety, tolerability, and pharmacokinetics of TMC310911, a novel human immunodeficiency virus type-1 protease inhibitor.

Methods: Healthy participants aged 18-55 years with body mass index 18-30 kg/m were enrolled in 2 phase 1 studies. In the first-in-human, single-dose study, 18 participants received placebo or TMC310911 (75-2000 mg) in the double-blind phase and 8 participants received 300 or 600 mg of TMC310911 [administered alone or with 100 mg ritonavir twice daily (bid)] in the subsequent open-label phase.

Antiviral activity, pharmacokinetics, and safety of the HIV-1 protease inhibitor TMC310911, coadministered with ritonavir, in treatment-naive HIV-1-infected patients.

Objectives: TMC310911 is a novel HIV type-1 (HIV-1) protease inhibitor with broad in vitro antiviral activity. In this phase 2a, open-label randomized study, the antiviral activity, pharmacokinetics, and safety and tolerability of ritonavir-boosted TMC310911 was assessed.

Methods: In this study, treatment-naive HIV-1 patients (aged 18-60 years) received 1 of the 4 dosing regimens of TMC310911: 150 mg twice-daily (bid) (n = 8), 300 mg bid (n = 8), 75 mg bid (n = 9), or 300 mg once-daily (qd) (n = 8), for 14 days, all coadministered with 100 mg of ritonavir, as only antiretroviral therapy.

Single-dose pharmacokinetics of pediatric and adult formulations of etravirine and swallowability of the 200-mg tablet: results from three Phase 1 studies.

Objectives: Three studies were conducted to assess the pharmacokinetics, methods of administration and ease of swallowability of etravirine tablets.

Methods: Two randomized studies in healthy adults investigated the single-dose pharmacokinetics of etravirine in various dosage strengths and the effects of dispersion in water and film-coating. A third study explored swallowability of etravirine 200-mg tablets in HIV-infected patients.

Impact of food and different meal types on the pharmacokinetics of rilpivirine.

The objective of the study was to determine the impact of food and different meal types on the pharmacokinetics of rilpivirine, a nonnucleoside reverse transcriptase inhibitor. In this open-label, randomized, crossover study, healthy volunteers received a single, oral 75 mg dose of rilpivirine either with a normal-fat breakfast (reference), under fasting conditions, with a high-fat breakfast, or with a protein-rich nutritional drink. Pharmacokinetic parameters were determined by non-compartmental methods and analyzed using a linear mixed-effects model.

Clinical perspective on drug-drug interactions with the non-nucleoside reverse transcriptase inhibitor rilpivirine.

Rilpivirine (TMC278) is a non-nucleoside reverse transcriptase inhibitor approved in combination with other antiretrovirals for the treatment of HIV-1 infection in treatment-naive adults (Edurant(®) 25 mg once daily; Complera(®) [USA]/Eviplera(®) [EU] once daily single-tablet regimen). Rilpivirine should be administered with a meal to optimize bioavailability. Its solubility is pH dependent.

Steady-state pharmacokinetics of etravirine and lopinavir/ritonavir melt extrusion formulation, alone and in combination, in healthy HIV-negative volunteers.

Background: A previous study investigating coadministration of etravirine, a nonnucleoside reverse transcriptase inhibitor, and lopinavir/ritonavir soft-gel formulation resulted in nonclinically relevant changes in etravirine and lopinavir exposure. The current study evaluated the pharmacokinetic interaction between etravirine and the lopinavir/ritonavir melt extrusion formulation.

Method: Sixteen human immunodeficiency virus (HIV)-negative volunteers were randomized to either treatment sequence A/B or B/A, with 14 days- washout between treatments (treatment A: etravirine 200 mg bid for 8 days; treatment B: lopinavir/ritonavir 400/100 mg bid for 16 days with etravirine 200 mg bid on days 9-16).