First Assessment in Humans of the Safety, Tolerability, Pharmacokinetics, and Ex Vivo Pharmacodynamic Antimalarial Activity of the New Artemisinin Derivative Artemisone

ABSTRACT In preclinical studies, artemisone (BAY 44-9585), a new artemisinin derivative, was shown to possess enhanced efficacy over artesunate, and it does not possess the neurotoxicity characteristic of the current artemisinins. In a phase I program with double-blind, randomized, placebo-controlled, single and multiple ascending oral-dose studies, we evaluated the safety, tolerability, pharmacokinetics, and ex vivo pharmacodynamic antimalarial activity of artemisone. Single doses (10, 20, 30, 40, and 80 mg) and multiple doses (40 and 80 mg daily for 3 days) of artemisone were administered orally to healthy subjects. Plasma concentrations of artemisone and its metabolites were measured by liquid chromatography/tandem mass spectrometry (LC/MS-MS). Artemisone was well tolerated, with no serious adverse events and no clinically relevant changes in laboratory and vital parameters. The pharmacokinetics of artemisone over the 10- to 80-mg range demonstrated dose linearity. After the single 80-mg dose, artemisone had a geometric mean maximum concentration of 140.2 ng/ml (range, 86.6 to 391.0), a short elimination half-life (t 1/2) of 2.79 h (range, 1.56 to 4.88), a high oral clearance of 284.1 liters/h (range, 106.7 to 546.7), and a large volume of distribution of 14.50 liters/kg (range, 3.21 to 51.58). Due to artemisone's short t 1/2, its pharmacokinetics were comparable after single and multiple dosing. Plasma samples taken after multiple dosing showed marked ex vivo pharmacodynamic antimalarial activities against two multidrug-resistant Plasmodium falciparum lines. Artemisone equivalent concentrations measured by bioassay revealed higher activity than artemisone measured by LC/MS-MS, confirming the presence of active metabolites. Comparable to those of other artemisinin's, artemisone's t 1/2 is well suited for artemisinin-based combination therapy for the treatment of P. falciparum malaria.

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First-in-Humans Study of the Safety, Tolerability, and Pharmacokinetics of ACT-451840, a New Chemical Entity with Antimalarial Activity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04125-14 ◽

2014 ◽

Vol 59 (2) ◽

pp. 935-942 ◽

Cited By ~ 17

Author(s):

Shirin Bruderer ◽

Noémie Hurst ◽

Ruben de Kanter ◽

Tommaso Miraval ◽

Thomas Pfeifer ◽

...

Keyword(s):

Antimalarial Activity ◽

Ex Vivo ◽

Plasma Concentrations ◽

New Drugs ◽

Active Metabolites ◽

Serious Adverse Events ◽

Time Curve ◽

Content Type ◽

Liquid Chromatography Tandem Mass ◽

Dose Study

ABSTRACTEmerging resistance to antimalarial agents raises the need for new drugs. ACT-451840 is a new compound with potent activity against sensitive and resistantPlasmodium falciparumstrains. This was a first-in-humans single-ascending-dose study to investigate the safety, tolerability, and pharmacokinetics of ACT-451840 across doses of 10, 50, 200, and 500 mg in healthy male subjects. In the 200- and 500-mg dose groups, the effect of food was investigated, and antimalarial activity was assessed using anex vivobioassay withP. falciparum. No (serious) adverse events leading to discontinuation were reported. At the highest dose level, the peak drug concentration (Cmax) and the area under the plasma concentration-time curve from zero to infinity of ACT-451840 under fasted conditions reached 11.9 ng/ml and 100.6 ng · h/ml, respectively, and these were approximately 13-fold higher under fed conditions. Food did not affect the half-life (approximately 34 h) of the drug, while theCmaxwas attained 2.0 and 3.5 h postdose under fasted and fed conditions, respectively. The plasma concentrations estimated by the bioassay were approximately 4-fold higher than those measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several potentially active metabolites were also identified. ACT-451840 was well tolerated across all doses. Exposure to ACT-451840 significantly increased with food. The bioassay indicated the presence of circulating active metabolites. (This study has been registered at ClinicalTrials.gov under registration no. NCT02186002.)

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Safety, Tolerability, and Pharmacokinetics of Telacebec (Q203), a New Antituberculosis Agent, in Healthy Subjects

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01436-21 ◽

2021 ◽

Author(s):

Jeongjun Kim ◽

Jinho Choi ◽

Hwankyu Kang ◽

Jiye Ahn ◽

Jane Hutchings ◽

...

Keyword(s):

Plasma Concentration ◽

Geometric Mean ◽

Plasma Concentrations ◽

Multidrug Resistant ◽

Drug Candidate ◽

Serious Adverse Events ◽

Double Blind ◽

Time Curve ◽

Exponential Decline ◽

Potent Drug

Telacebec (Q203) is a potent drug candidate under clinical development for the treatment of drug-naïve and drug-resistant tuberculosis. The first-in-human randomized, placebo-controlled, double-blind, dose-escalation Phase 1A trial (Q203-TB-PI-US001) was conducted to evaluate the safety, tolerability, and pharmacokinetics of telacebec. A total of 56 normal, healthy, male and female subjects (42 active and 14 placebo) were enrolled in the study. The doses of telacebec were 10 mg (Cohort 1), 30 mg (Cohort 2), 50 mg (Cohort 3), 100 mg (Cohort 4), 200 mg (Cohort 5), 400 mg (Cohort 6), and 800 mg (Cohort 7) in a fasted state. Subjects participating in Cohort 4 were also enrolled in Cohort 8 to investigate the food effect on the pharmacokinetics of telacebec after a high-fat meal. In all subjects dosed with telacebec (10 – 800 mg), telacebec was well tolerated and did not lead to any significant or serious adverse events. Following a single oral administration of telacebec (10 – 800 mg), telacebec plasma concentration reached the maximal plasma concentration (C max ) in average 2.0 – 3.5 h and showed multi-exponential decline thereafter. The area under the plasma concentration vs. time curve (AUC) was approximately dose-proportional. A significant increase in plasma concentrations was observed in the fed condition compared with the fasted condition with the geometric mean ratio of 3.93 for C max . Moderate delay in T max (4.5 h) was also observed in the fed condition. These results, combined with the demonstrated activity against drug-sensitive and multidrug-resistant Mycobacterium tuberculosis , support further investigation of telacebec for the treatment of tuberculosis.

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Pharmacokinetics and Safety Assessment of Anti-HIV Dapivirine Vaginal Microbicide Rings with Multiple Dosing

10.31234/osf.io/su2kw ◽

2020 ◽

Author(s):

Lungwani Muungo

Keyword(s):

Ex Vivo ◽

Oral Treatment ◽

Plasma Concentrations ◽

Vaginal Ring ◽

Vaginal Fluid ◽

Cervical Tissue ◽

Double Blind ◽

Group A ◽

Group B ◽

Anti Hiv

Objectives: Self-administered vaginal rings are a promising method for delivery of topical anti-HIV microbicidesand might offer an adherence advantage over daily or coitally-dependent dosage forms such as gels. This trialassessed the safety and pharmacokinetic aspects of the Dapivirine Vaginal Ring-004 when worn as multiple rings oversequential periods of ring use by healthy, sexually-active, HIV-negative women.Methods: This double-blind trial was conducted among 48 women (18-40 years). Participants were randomlyassigned to two groups (A or B) and received (3:1) either the dapivirine or a placebo vaginal ring. Group A used tworings over a 56-day period and Group B used three rings over a 57-day period. Safety evaluations were conductedthroughout the trial. Dapivirine concentrations were measured in plasma, vaginal fluid and cervical tissue samplescollected during and after the 56 days (Group A) or 57 days (Group B) of vaginal ring use.Results: Ring-004 was safe and well tolerated in all participants. The pharmacokinetic profile demonstrated arapid increase in plasma and vaginal fluid concentrations and achieved concentrations in vaginal fluids and cervicaltissue well above the in vitro IC99 in cervical tissue (3.3 ng/mL) that were sustained for a 28 to 35-day ring use period(approximately 3000 times higher in vaginal fluids and 14 -1000 times higher in cervical tissue). Drug levels wereassociated with significant inhibitory activity of genital secretions against HIV ex vivo, a biomarker of pharmacodynamics.Individual plasma dapivirine concentrations did not exceed 553 pg/mL and were well below plasma concentrations atthe maximum tolerated dose for oral treatment (mean Cmax 2286 ng/mL).Conclusions: The consecutive use of several rings over a period of up to 57 days was safe and well tolerated, andPK data indicate that a single Ring-004 is likely to be protective for at least 35 days.

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Efficacy and Safety of a 3-Antigen (Pre-S1/Pre-S2/S) Hepatitis B Vaccine: Results of a Phase 3 Randomized Clinical Trial in the Russian Federation

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1649 ◽

2020 ◽

Author(s):

Elena V Esaulenko ◽

Aleksey A Yakovlev ◽

Genady A Volkov ◽

Anastasia A Sukhoruk ◽

Kirill G Surkov ◽

...

Keyword(s):

Hepatitis B ◽

Geometric Mean ◽

Serious Adverse Events ◽

Double Blind ◽

Antigen Vaccine ◽

Single Antigen ◽

Antibody Titers ◽

The Russian Federation ◽

The Difference ◽

Mean Concentration

Abstract Background This study compares the immunogenicity and safety of a 3-antigen (S/pre-S1/pre-S2) hepatitis B (HepB) vaccine (3AV), to a single antigen vaccine (1AV) in adults to support the registration of 3AV in Russia. Methods We conducted a randomized, double-blind, comparative study of 3-dose regimens of 3AV (10 μg) and 1AV (20 µg) in adults aged 18–45 years. We evaluated immunogenicity based on hepatitis B surface (HBs) antibody titers at days 1, 28, 90, 180, and 210, adverse and serious adverse events (SAEs) to study day 210. The primary outcome was based on the difference in rates of seroconversion at day 210 (lower bound 95% confidence interval [CI]: > − 4%). Secondary outcomes were seroprotection rates (SPR), defined as anti-HBs ≥10 mIU/mL and anti-HBs geometric mean concentration (GMC). Results Rate of seroconversion in 3AV (100%) was noninferior to 1AV (97.9%) at study day 210 (difference: 2.1%, 95% CI: −2.0, 6.3%]) but significantly higher at study day 28. SPR at study day 210 was >97% in both arms. Anti-HBs titers were significantly higher at study days 90 (P = .001) and 180 (P = .0001) with 3AV. Sex, age, and body mass index (BMI) had no impact on anti-HBs titers. The rates of local reactions related to vaccination were similar between vaccine arms (3AV vs 1AV) after the first (30% vs 18.8%, P = .15), second (20.0% vs 14.6%, P = .33), and third vaccination (14.9% vs 23.4%, P = .22). No SAEs were reported. Conclusions 3AV was noninferior to 1AV. 3AV induced high SPR, and there were no safety concerns. Clinical Trials Registration. NCT04209400.

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Tonabersat, a Gap-Junction Modulator: Efficacy and Safety in Two Randomized, Placebo-Controlled, Dose-Ranging Studies of Acute Migraineceph

Cephalalgia ◽

10.1111/j.1468-2982.2009.01974.x ◽

2009 ◽

Vol 29 (2_suppl) ◽

pp. 17-27 ◽

Cited By ~ 31

Author(s):

SD Silberstein ◽

J Schoenen ◽

H Göbel ◽

HC Diener ◽

AH Elkind ◽

...

Keyword(s):

Adverse Events ◽

North American ◽

Cortical Spreading Depression ◽

Spreading Depression ◽

Plasma Concentrations ◽

International Study ◽

Maximum Plasma ◽

Serious Adverse Events ◽

Double Blind ◽

Dose Ranging

Tonabersat is a novel benzopyran derivative that blocks the cortical spreading depression proposed to be associated with migraine attacks. The ability of single oral doses of 15, 25, 40 and 80 mg of tonabersat to relieve the symptoms of moderate to severe migraine was evaluated in 859 migraineurs enrolled in two dose-ranging, double-blind, randomized, placebo-controlled, parallel-group trials, one international and the other North American. In the international study, significantly more patients given tonabersat than given placebo experienced relief of headache pain at 2 h (15 mg, 36.8%; 40 mg, 40.7%), the principal efficacy variable, and at 4 h (40 mg, 63.0%) and complete abolition of headache at 4 h (40 mg, 34.3%). None of the primary or secondary efficacy variables indicated significant differences between tonabersat and placebo in the North American study. Tonabersat was generally well tolerated, with dizziness and nausea the most common side-effects. Serious adverse events were uncommon, and no patient withdrew from either study because of adverse events. These results suggest a possible interplay between tonabersat pharmacokinetics (the relatively long time required to reach maximum plasma concentrations) and patient characteristics (previous triptan exposure) in the management of acute migraine attacks. Based on the pharmacokinetics and actions on cortical spreading depression, tonabersat may have potential value in migraine prophylaxis.

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INITIAL STUDIES IN MAN WITH A NOVEL THROMBOXANE RECEPTOR BLOCKING DRUG GR32191

10.1055/s-0038-1643467 ◽

1987 ◽

Author(s):

M Thomas ◽

P Lumley ◽

P Ballard ◽

J R O'Brien

Keyword(s):

Platelet Aggregation ◽

Bleeding Time ◽

Ex Vivo ◽

Plasma Concentrations ◽

Blocking Drug ◽

Double Blind ◽

Receptor Blocking ◽

Thromboxane Receptor ◽

Pre Treatment ◽

Induced Aggregation

In-vitro GR32191 is a potent and specific thromboxane receptor blocking drug on platelets, and vascular and airways smooth muscle (Lumley et al this meeting). We have undertaken studies in healthy male subjects (n) to examine the effects of oral GR32191 upon platelet aggregation ex-vivo and template bleeding time. Platelet aggregation was monitored in whole blood by counting platelets electronically. Concentration-effect curves to U-46619 and ADP were constructed prior to and following drug or placebo. The degree of rightward displacement of a curve due to treatment was expressed as a concentration-ratio (CR) which was calculated at the 50% aggregation level (ECso post-treatment ECso pre-treatment). Plasma concentrations of GR32191 were determined by h.p.l.c. After single doses of GR32191 mean peak CR's of 8 and 80 were achieved with 0.125 and 0.25mg/kg (n=4) and values of 74 and 234 with 0.5 and lmg/kg (n=4). Peak effects were seen within 2 hours of dosing while activity was still present between 8 and 24 hours. ADP-induced aggregation was unaffected by drug (CR<2) and placebo was without significant effect upon the sensitivity to either aggregating agent (CR<2). GR32191 was rapidly absorbed and the plasma elimination half-life was about 2 hours. GR32191 17.5mg 12-hourly for 10 days (n=6) produced a progressive antagonism of U-46619 induced aggregation which resulted in a large continuous blockade in all subjects (range of 12htrough CR's 85 to 287). However, plasma concentrations of GR32191 did not accumulate on repeated administration. In a double-blind, placebo-controlled, cross-over study (n=16), a statistically significant (p= 0.002) increase in bleeding time was seen following treatment with GR32191 40mg twice daily for 7 days (pre-treatment mean 3.79 min, post-placebo mean 3.47 min, post-GR32191 mean 5.42 min). Rectal bleeding (n=l) has occurred with GR32191 but otherwise tolerability has been good. No drug related changes have been seen in routine laboratory safety screens. Clinical studies are in progress.

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Single-Ascending-Dose Pharmacokinetics and Safety of the Novel Broad-Spectrum Antifungal Triazole BAL4815 after Intravenous Infusions (50, 100, and 200 Milligrams) and Oral Administrations (100, 200, and 400 Milligrams) of Its Prodrug, BAL8557, in Healthy Volunteers

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.1.279-285.2006 ◽

2006 ◽

Vol 50 (1) ◽

pp. 279-285 ◽

Cited By ~ 103

Author(s):

Anne Schmitt-Hoffmann ◽

Brigitte Roos ◽

Markus Heep ◽

Michael Schleimer ◽

Erhard Weidekamm ◽

...

Keyword(s):

Broad Spectrum ◽

Plasma Concentrations ◽

Pathogenic Fungi ◽

Volume Of Distribution ◽

The Body ◽

Water Soluble ◽

Maximum Plasma ◽

Serious Adverse Events ◽

Time Curve ◽

To Receive

ABSTRACT BAL8557 is the water-soluble prodrug of a novel antifungal triazole, BAL4815. BAL4815 is active against a broad spectrum of major opportunistic and pathogenic fungi, including strains that are resistant to other azoles. Cohorts of healthy male subjects received single-ascending oral (p.o.) doses of BAL8557 that were equivalent to 100, 200, or 400 mg of BAL4815 or single-ascending, 1-h constant-rate intravenous (i.v.) infusions of BAL8557 which were equivalent to 50, 100, or 200 mg of BAL4815. In each cohort, six subjects were randomly assigned to receive active drug and two subjects were assigned to receive the placebo. All doses were well tolerated, and no severe or serious adverse events occurred. Maximum plasma concentrations of BAL4815 were observed 1.5 to 3 h after p.o. drug intake or at the end of the 1-h infusion. After both routes of administration, values for maximum drug concentration observed in plasma and area under the concentration-time curve increased slightly more than proportionally to the administered dose. Mean elimination half-lives were particularly long (56 to 77 h after p.o. administration and 76 to 104 h after i.v. administration). The volume of distribution was large (155 to 292 liters after p.o. administration and 304 to 494 liters after i.v. administration) and systemic clearance was low (1.9 to 2.8 liter/h after p.o. administration and 2.8 to 5.0 liter/h after i.v. administration). Urinary recovery of BAL4815 was less than 0.4% of the infused dose. Based on the exposure data, oral bioavailability of BAL4815 is assumed to be very high. The pharmacokinetics of BAL4815 are well suited to maintaining concentrations of BAL4815 for a long period of time in the body and to enabling an effective treatment of systemic mycoses.

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Pharmacokinetics, Pharmacodynamics and Tolerability of a Potent, Non-peptidic, GP IIb/IIIa Receptor Antagonist following Multiple Oral Administrations of a Prodrug Form

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614238 ◽

1998 ◽

Vol 79 (01) ◽

pp. 169-176 ◽

Cited By ~ 27

Author(s):

Nishit Modi ◽

Sherron Bullens ◽

Cheryl Pater ◽

Michael Lipari ◽

Kirk Robarge ◽

...

Keyword(s):

Half Life ◽

Rhesus Monkeys ◽

Ex Vivo ◽

Active Form ◽

Plasma Concentrations ◽

Volume Of Distribution ◽

A Value ◽

Terminal Half Life ◽

The Right

SummaryRo 44-3888 is a potent and selective antagonist of GP IIb/IIIa. Following IV administration to rhesus monkeys, the (mean ± SD.) clear ance, volume of distribution and terminal half-life of Ro 44-3888 were 4.4 ± 1.8 ml/min/kg, 0.8 ± 0.4 l/kg and 2.5 ± 0.8 h respectively. Oral administration of Ro 48-3657 (1 mg/kg), a doubly protected prodrug form, produced peak concentrations of Ro 44-3888 (152 ± 51 ng/ml), 4.2 ± 2.2 h after dosing. Terminal half-life and estimated bioavailabil ity were 5.1 ± 1.6 h and 33 ± 6% respectively. No effect on blood pressure, heart rate or platelet counts were seen. Adenosine diphosohate (ADP) induced platelet aggregation (PA) and cutaneous bleeding times (CBT) were determined prior to and after the last of 8 daily oral administrations of Ro 48-3657 (0.25 or 0.5 mg/kg) to eight rhesus monkeys. Peak and trough plasma concentrations were proportional to dose and steady state was achieved after the second administration. Inhibition of PA and prolongation of CBT were concentration dependent. The ex vivo IC50 (82 nM) for ADP-mediated PA correlated with a value (58 nM) determined in vitro. The CBT response curve was displaced to the right of the PA curve. CBT was prolonged to ≥25 min when levels of Ro 44-3888 exceeded 190 nM and PA was >90% inhibited. Therefore, in rhesus monkeys, Ro 48-3657 is reproducibly absorbed and converted to its active form, is well tolerated, and has a concentration-dependent effect on PA and CBT. These properties make Ro 48-3657 an attractive candidate for evaluation in patients at high risk for arterial thrombosis.

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Randomized, Controlled Trial of a 13-Valent Pneumococcal Conjugate Vaccine Administered Concomitantly with an Influenza Vaccine in Healthy Adults

Clinical and Vaccine Immunology ◽

10.1128/cvi.00176-12 ◽

2012 ◽

Vol 19 (8) ◽

pp. 1296-1303 ◽

Cited By ~ 39

Author(s):

Robert W. Frenck ◽

Alejandra Gurtman ◽

John Rubino ◽

William Smith ◽

Martin van Cleeff ◽

...

Keyword(s):

Influenza Vaccine ◽

Conjugate Vaccine ◽

Pneumococcal Conjugate Vaccine ◽

Controlled Trial ◽

Geometric Mean ◽

Enzyme Linked Immunosorbent Assay ◽

Serious Adverse Events ◽

Double Blind ◽

Group 2 ◽

Group 1

ABSTRACTA randomized, double-blind, phase 3 trial evaluated the immunogenicity, safety, and tolerability of a 13-valent pneumococcal conjugate vaccine (PCV13) coadministered with trivalent inactivated influenza vaccine (TIV) in pneumococcal vaccine-naive adults. Participants ages 50 to 59 years (n= 1,116) received TIV with PCV13 (group 1) or placebo (group 2) (1:1 randomization); 1 month later, group 1 received placebo and group 2 received PCV13. A hemagglutination inhibition (HAI) assay for TIV and a standardized enzyme-linked immunosorbent assay for pneumococcal serotype-specific immunoglobulin G (IgG) were performed and opsonophagocytic activity (OPA) titers (assessedpost hoc) were measured at baseline and 1 and 2 months postvaccination. The rises in HAI assay geometric mean titer (GMT) and percentage of participants in groups 1 and 2 with ≥4-fold increases in HAI responses (A/H1N1, 84.0% and 81.2%, respectively; A/H3N2, 71.1% and 69.5%, respectively; and B, 60.6% and 60.3%, respectively) were similar. In group 1, all serotypes met the predefined IgG geometric mean concentration (GMC) ratio noninferiority criterion relative to group 2, but GMCs were lower in group 1 than group 2. When comparing group 1 with group 2, 5 serotypes did not meet the OPA GMT ratio noninferiority criterion, and OPA GMTs were significantly lower for 10 serotypes. PCV13 injection site reactions were similar and mostly mild in both groups. Systemic events were more frequent in group 1 (86.2%) than group 2 (76.7%;P< 0.001); no vaccine-related serious adverse events occurred. Coadministration of PCV13 and TIV was well tolerated but associated with lower PCV13 antibody responses and is of unknown clinical significance. Given the positive immunologic attributes of PCV13, concomitant administration with TIV should be dictated by clinical circumstances.

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Safety and Pharmacokinetics of Brecanavir, a Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, following Repeat Administration with and without Ritonavir in Healthy Adult Subjects

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01005-06 ◽

2007 ◽

Vol 51 (4) ◽

pp. 1202-1208 ◽

Cited By ~ 4

Author(s):

Y. Sunila Reddy ◽

Susan L. Ford ◽

Maggie T. Anderson ◽

Sharon C. Murray ◽

Judith Ng-Cashin ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Protease Inhibitor ◽

Geometric Mean ◽

Repeat Dose ◽

Serious Adverse Events ◽

Double Blind ◽

Immunodeficiency Virus ◽

Potent Protease Inhibitor ◽

Hiv 1

ABSTRACT Brecanavir (BCV) is a novel, potent protease inhibitor in development for the treatment of human immunodeficiency virus (HIV-1) infection with low nM in vitro 50% inhibitory concentrations (IC50s) against many multiprotease inhibitor resistant viruses. This study was a double-blind, randomized, placebo-controlled repeat-dose escalation to evaluate the safety, tolerability, and pharmacokinetics of BCV, with or without ritonavir (RTV), in 68 healthy subjects. Seven sequential cohorts (n = 10) received BCV (50 to 600 mg) in combination with 100 mg RTV (every 12 h [q12h] or q24h) or alone at 800 mg q12h for 15 days. BCV alone or in combination with RTV was well tolerated, with no serious adverse events reported. The most common drug-related adverse event was headache. BCV was readily absorbed with median time to maximum concentration of drug in serum values ranging from 2.5 to 5.0 h postdose following single- and repeat-dose administration of BCV alone and BCV with RTV 100 mg. Geometric mean BCV accumulation ratios ranged from 1.4 to 1.56 following BCV-RTV q24h regimens and from 1.84 to 4.93 following BCV q12h regimens. BCV steady state was generally achieved by day 13 in all groups. All day 15 BCV-RTV trough concentration values in q12h regimens reached or surpassed the estimated protein-binding corrected in vitro IC50 target BCV concentration of 28 ng/ml for highly resistant isolates. The pharmacokinetic and safety profile of BCV-RTV supports continued investigation in HIV-1-infected subjects.

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