Pharmacokinetics of Temsavir, the Active Moiety of the HIV-1 Attachment Inhibitor Prodrug, Fostemsavir, Coadministered with Cobicistat, Etravirine, Darunavir/Cobicistat, or Darunavir/Ritonavir with or without Etravirine in Healthy Participants.

Fostemsavir is a prodrug of temsavir, a first-in-class attachment inhibitor that binds directly to HIV-1 gp120, preventing initial viral attachment and entry into host CD4 T cells with demonstrated efficacy in phase 2 and 3. Temsavir is a P-glycoprotein and breast cancer resistance protein (BCRP) substrate; its metabolism is mediated by esterase and CYP3A4 enzymes. Drugs that induce or inhibit CYP3A, P-glycoprotein, and BCRP may affect temsavir concentrations.

Evaluation of the pharmacokinetic drug-drug interaction between the antiretroviral agents fostemsavir and maraviroc: a single-sequence crossover study in healthy participants.

Background: Fostemsavir is an oral prodrug of temsavir, a first-in-class attachment inhibitor that binds HIV-1 gp120, preventing initial HIV attachment and entry into host immune cells.

Objective: The pharmacokinetic interaction was determined between temsavir and maraviroc, a CCR5 allosteric inhibitor indicated for CCR5-tropic HIV-1 that may be co-administered with fostemsavir as part of combination antiretroviral therapy in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection.

Methods: This was a Phase 1, open-label, single-sequence, 3-period crossover study evaluating the effect of fostemsavir on maraviroc pharmacokinetics and the effect of maraviroc on temsavir pharmacokinetics (ClinicalTrials.

Prevalence of gp160 polymorphisms known to be related to decreased susceptibility to temsavir in different subtypes of HIV-1 in the Los Alamos National Laboratory HIV Sequence Database.

Background: Fostemsavir, a prodrug of the gp120-directed attachment inhibitor temsavir, is indicated for use in heavily treatment-experienced individuals with MDR HIV-1. Reduced susceptibility to temsavir in the clinic maps to discrete changes at amino acid positions in gp160: S375, M426, M434 and M475.

Objectives: To query the Los Alamos National Laboratory (LANL) HIV Sequence Database for the prevalence of polymorphisms at gp160 positions of interest.

Patient-Reported Outcomes in the Phase III BRIGHTE Trial of the HIV-1 Attachment Inhibitor Prodrug Fostemsavir in Heavily Treatment-Experienced Individuals.

Introduction: Heavily treatment-experienced (HTE) people living with HIV-1 (PLWH) have limited viable antiretroviral regimens available because of multidrug resistance and safety concerns. The first-in-class HIV-1 attachment inhibitor fostemsavir demonstrated efficacy and safety in HTE participants in the ongoing phase III BRIGHTE trial.

Objectives: We describe patient-reported outcomes (PROs) through week 48.

Long-term efficacy and safety of fostemsavir among subgroups of heavily treatment-experienced adults with HIV-1.

Objectives: The aim of this study was to understand how demographic and treatment-related factors impact responses to fostemsavir-based regimens.

Design: BRIGHTE is an ongoing phase 3 study evaluating twice-daily fostemsavir 600 mg and optimized background therapy (OBT) in heavily treatment-experienced individuals failing antiretroviral therapy with limited treatment options (Randomized Cohort 1-2 and Nonrandomized Cohort 0 fully active antiretroviral classes).

Methods: Virologic response rates (HIV-1 RNA <40 copies/ml, Snapshot analysis) and CD4+ T-cell count increases in the Randomized Cohort were analysed by prespecified baseline characteristics (age, race, sex, region, HIV-1 RNA, CD4+ T-cell count) and viral susceptibility to OBT.

Effect of Renal and Hepatic Impairment on the Pharmacokinetics of Temsavir, the Active Moiety of Fostemsavir.

The oral prodrug fostemsavir (GSK3684394, formerly BMS-663068) is an antiretroviral treatment for HIV-1. Fostemsavir is metabolized to its active moiety, temsavir, a first-in-class HIV-1 attachment inhibitor that binds to the viral envelope glycoprotein 120. Long-term antiretroviral therapy, the resulting longer life expectancy, and/or certain coinfections can increase the risk of chronic liver and kidney disease in HIV-1-infected individuals.

Susceptibility of global HIV-1 clinical isolates to fostemsavir using the PhenoSense® Entry assay.

Background: Fostemsavir is a prodrug of a first-in-class HIV-1 attachment inhibitor, temsavir, that binds to gp120 and blocks attachment to the host-cell CD4 receptor, preventing entry and infection of the target cell. Previous studies using a limited number of clinical isolates showed that there was intrinsic variability in their susceptibility to temsavir.

Objectives: Here, an analysis was performed using all clinical isolates analysed in the Monogram Biosciences PhenoSense® Entry assay as part of the development programme.

Safety and efficacy of the HIV-1 attachment inhibitor prodrug fostemsavir in heavily treatment-experienced individuals: week 96 results of the phase 3 BRIGHTE study.

Background: Fostemsavir, a prodrug of the first-in-class attachment inhibitor, temsavir, is indicated for heavily treatment-experienced individuals with multidrug-resistant HIV-1. We previously reported superior efficacy of fostemsavir versus placebo in the randomised cohort of the BRIGHTE study after 8-day functional monotherapy (primary endpoint); here we report planned interim analyses through week 96.

Methods: BRIGHTE (NCT02362503) is an ongoing multicentre, two-cohort, phase 3 trial, done at 108 centres in 22 countries.

Fostemsavir in Adults with Multidrug-Resistant HIV-1 Infection.

Background: Among some patients with human immunodeficiency virus type 1 (HIV-1) infection who have undergone multiple antiretroviral therapies and have limited options for treatment, new classes of antiretroviral drugs with novel mechanisms of action are needed. Fostemsavir is the prodrug of temsavir, a first-in-class investigational HIV-1 attachment inhibitor.

Methods: In this ongoing phase 3 trial in 23 countries, we enrolled patients with multidrug-resistant HIV-1 infection in two cohorts, according to their remaining treatment options.

Effects of Temsavir, Active Moiety of Antiretroviral Agent Fostemsavir, on QT Interval: Results From a Phase I Study and an Exposure-Response Analysis.

Fostemsavir, a prodrug of human immunodeficiency virus attachment inhibitor temsavir (TMR), is in phase III development in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type I (HIV-1) infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection for whom it is otherwise not possible to construct a suppressive antiviral regimen due to resistance, intolerance, or safety considerations. The proarrhythmic potential of fostemsavir was studied in a thorough QT study and exposure-response modeling was performed at therapeutic and supratherapeutic concentrations of TMR. Fostemsavir 1,200 mg b.

Methadone and buprenorphine pharmacokinetics and pharmacodynamics when coadministered with fostemsavir to opioid-dependent, human immunodeficiency virus seronegative participants.

Aims: Regional human immunodeficiency virus (HIV) prevalence rates are high in people with history of injection drug use, including those managed with maintenance opioids. Fostemsavir (FTR) is an oral prodrug of temsavir, a first-in-class attachment inhibitor that binds HIV-1 gp120, preventing initial HIV attachment and entry into host immune cells. Here we determine the impact of FTR on the pharmacokinetics of opioids methadone (MET: R-, S- and total) or buprenorphine and norbuprenorphine (BUP and norBUP) when coadministered.

Safety, efficacy, and dose response of the maturation inhibitor GSK3532795 (formerly known as BMS-955176) plus tenofovir/emtricitabine once daily in treatment-naive HIV-1-infected adults: Week 24 primary analysis from a randomized Phase IIb trial.

GSK3532795 (formerly known as BMS-955176) is a second-generation maturation inhibitor targeting a specific Gag cleavage site between capsid p24 and spacer peptide 1 of HIV-1. Study 205891 (previously AI468038) investigated the efficacy, safety, and dose response of GSK3532795 in treatment-naive, HIV-1-infected participants. Study 205891 (NCT02415595) was a Phase IIb, randomized, active-controlled, double-blind, international trial.

Large-scale surveillance study of the safety and effectiveness of entecavir in Korean patients with chronic hepatitis B.

Background/aims: Entecavir (ETV) is effective and safe antiviral agent against hepatitis B virus (HBV) in clinical and real-world setting but, most studies were performed in single institute or have limitation in patient's number. A large-scale nation-wide real-world surveillance study was carried out to investigate safety, efficacy and clinical effectiveness of ETV in Korean patients with chronic hepatitis B (CHB).

Methods: Between 2006 and 2012, 3,444 patients were enrolled from 132 Korean institutions.

Covalently closed-circular hepatitis B virus DNA reduction with entecavir or lamivudine.

Aim: To investigate the reduction in hepatitis B virus (HBV) covalently closed-circular DNA (cccDNA) with entecavir (ETV) or lamivudine (LAM).

Methods: This analysis included patients who had participated in the randomized Phase III study ETV-022 comparing ETV vs LAM in nucleos(t)ide-naive, HBeAg-positive patients. Patients received ETV (0.

Quantification of HBsAg in nucleos(t)ide-naïve patients treated for chronic hepatitis B with entecavir with or without tenofovir in the BE-LOW study.

Background & Aims: Serum hepatitis B surface antigen (HBsAg) levels may predict treatment response in chronic hepatitis B (CHB). We examined the association between changes in HBsAg levels and response to treatment in the BE-LOW study.

Methods: In this open-label, multicentre study, 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive or -negative CHB were randomized and treated with daily entecavir 0.

The Discovery and Development of a Potent Antiviral Drug, Entecavir, for the Treatment of Chronic Hepatitis B.

Since the first approval of interferon for the treatment of chronic hepatitis B virus (HBV) infection in 1992, six additional antivirals have been developed: pegylated interferon-alfa2a, and the oral antivirals lamivudine, adefovir, telbivudine, entecavir and tenofovir. The availability of animal models for HBV infection and hepatocyte cell culture led to the discovery and development of oral antivirals targeted at HBV polymerase and reverse transcriptase, which inhibit viral replication. The discovery and development of entecavir, the first oral anti-HBV drug with both potent antiviral activity and a high genetic barrier to resistance, took more than 10 years before it was first approved in the USA.

Entecavir and hepatitis B immune globulin in patients undergoing liver transplantation for chronic hepatitis B.

For patients undergoing liver transplantation (LT) for hepatitis B virus (HBV)-related liver disease, the current standard of care for preventing reinfection of the allograft is nucleoside analogue therapy combined with hepatitis B immune globulin (HBIG). Entecavir has demonstrated high efficacy and a favorable safety profile for chronic hepatitis B (CHB) treatment, but data for patients undergoing HBV-related LT are limited. This study assessed the safety and efficacy of entecavir combined with various HBIG regimens after CHB-related LT.

Quantitative hepatitis B surface antigen analysis in hepatitis B e antigen-positive nucleoside-naive patients treated with entecavir.

Background: Entecavir is a potent nucleoside analogue for treating chronic hepatitis B (CHB). Quantitative hepatitis B surface antigen (qHBsAg) levels are predictive of response to interferon-α in CHB treatment; however, the clinical utility of qHBsAg in nucleoside/nucleotide analogue-based CHB therapy is not fully characterized. This study assessed changes in qHBsAg in patients treated with entecavir in the Phase III study ETV-022.

Efficacy of entecavir with or without tenofovir disoproxil fumarate for nucleos(t)ide-naïve patients with chronic hepatitis B.

Background & Aims: Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent antiviral agents that might have additive or synergistic antiviral activity in treatment of patients with chronic hepatitis B (CHB). We compared the efficacy and safety of ETV monotherapy with those of a combination of ETV and TDF.

Methods: We performed a randomized, open-label, multicenter, superiority study of 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive (n = 264) or HBeAg-negative (n = 115) CHB.

Virologic, serologic, and biochemical outcomes through 2 years of treatment with entecavir and lamivudine in nucleoside-naïve Chinese patients with chronic hepatitis B: a randomized, multicenter study.

Purpose: Entecavir demonstrated superior virologic and biochemical benefits over lamivudine at 48 weeks in nucleoside-naïve Chinese patients with chronic hepatitis B (CHB). We evaluated the effect of continued entecavir and lamivudine treatment in patients who continued treatment in year 2 and the off-treatment durability of patients who achieved a protocol-defined consolidated response at week 48.

Methods: Chinese adults (n = 519) with CHB were randomized to a minimum of 52 weeks of treatment with entecavir 0.