A Phase IIa Study Evaluating Safety, Pharmacokinetics, and Antiviral Activity of GSK2838232, a Novel, Second-generation Maturation Inhibitor, in Participants With Human Immunodeficiency Virus Type 1 Infection

2019 ◽  
Vol 71 (5) ◽  
pp. 1255-1262 ◽  
Author(s):  
Edwin DeJesus ◽  
Sara Harward ◽  
Roxanne C Jewell ◽  
Mark Johnson ◽  
Etienne Dumont ◽  
...  

Abstract Background GSK2838232 is a second-generation, potent, small-molecule, oral human immunodeficiency virus type 1 (HIV-1) maturation inhibitor for once-daily administration boosted with a pharmacoenhancer. Methods The phase 2a, proof-of-concept study was an open-label, adaptive dose-ranging design. Safety, pharmacokinetics, and efficacy of GSK2838232 boosted by cobicistat were evaluated in individuals with HIV-1 infection. The study participants (N = 33) received GSK2838232 once daily across a range of doses (20–200 mg) with cobicistat 150 mg for 10 days. Results GSK2838232 was safe and well tolerated with no clinically meaningful changes in safety parameters or adverse events. Exposure (maximum concentration and area under the concentration-time curve from time zero to the concentration at 24 hours postdose) increased 2- to 3-fold with repeated dosing in an approximately dose-proportional manner, reaching steady-state by day 8 with a half-life (t½) from 16.3 to 19.2 hours. Clearance and t½ values were not dependent on dose. Viral load declined from baseline with all GSK2838232 doses. Mean maximum declines from baseline to day 11 in HIV-1 RNA log10 copies/mL with the 20-mg, 50-mg, 100-mg, and 200-mg cohorts were −0.67, −1.56, −1.32, and −1.70, respectively. CD4+ cell counts increased at doses ≥50 mg. Conclusions GSK2838232 with cobicistat was well tolerated and exhibited efficacy as a short-term monotherapy in participants with HIV-1. This positive proof-of-concept study supports the continued development of GSK2838232 for the treatment of HIV as part of combination antiretroviral therapy. Clinical Trials Registration NCT03045861.

2006 ◽  
Vol 80 (22) ◽  
pp. 10957-10971 ◽  
Author(s):  
Catherine S. Adamson ◽  
Sherimay D. Ablan ◽  
Ioana Boeras ◽  
Ritu Goila-Gaur ◽  
Ferri Soheilian ◽  
...  

ABSTRACT 3-O-(3′,3′-dimethylsuccinyl)betulinic acid (PA-457 or bevirimat) potently inhibits human immunodeficiency virus type 1 (HIV-1) maturation by blocking a late step in the Gag processing pathway, specifically the cleavage of SP1 from the C terminus of capsid (CA). To gain insights into the mechanism(s) by which HIV-1 could evolve resistance to PA-457 and to evaluate the likelihood of such resistance arising in PA-457-treated patients, we sought to identify and characterize a broad spectrum of HIV-1 variants capable of conferring resistance to this compound. Numerous independent rounds of selection repeatedly identified six single-amino-acid substitutions that independently confer PA-457 resistance: three at or near the C terminus of CA (CA-H226Y, -L231F, and -L231M) and three at the first and third residues of SP1 (SP1-A1V, -A3T, and -A3V). We determined that mutations CA-H226Y, CA-L231F, CA-L231M, and SP1-A1V do not impose a significant replication defect on HIV-1 in culture. In contrast, mutations SP1-A3V and -A3T severely impaired virus replication and inhibited virion core condensation. The replication defect imposed by SP1-A3V was reversed by a second-site compensatory mutation in CA (CA-G225S). Intriguingly, high concentrations of PA-457 enhanced the maturation of SP1 residue 3 mutants. The different phenotypes associated with mutations that confer PA-457 resistance suggest the existence of multiple mechanisms by which HIV-1 can evolve resistance to this maturation inhibitor. These findings have implications for the ongoing development of PA-457 to treat HIV-1 infection in vivo.


2003 ◽  
Vol 77 (1) ◽  
pp. 237-244 ◽  
Author(s):  
James P. McGettigan ◽  
Roger J. Pomerantz ◽  
Catherine A. Siler ◽  
Philip M. McKenna ◽  
Heather D. Foley ◽  
...  

ABSTRACT Rabies virus (RV) vaccine strain-based vectors show great promise as vaccines against other viral diseases such as human immunodeficiency virus type 1 (HIV-1) infection and hepatitis C, but a low residual pathogenicity remains a concern for their use. Here we describe several highly attenuated second-generation RV-based vaccine vehicles expressing HIV-1 Gag. For this approach, we modified the previously described RV vaccine vector SPBN by replacing the arginine at position 333 (R333) within the RV glycoprotein (G) with glutamic acid (E333), deleting 43 amino acids of the RV G cytoplasmic domain (CD), or combining the R333 exchange and the CD deletion. In addition, we constructed a new RV vector that expresses HIV-1 Gag from an RV transcription unit upstream of the RV phosphoprotein gene (BNSP-Gag) instead of upstream of the G gene. As expected and as demonstrated for SPBN-Gag, all vaccine vehicles were apathogenic after peripheral administration. However, the new, second-generation vaccine vectors containing modifications in the RV G were also apathogenic after intracranial infection with 105 infectious particles, and BNSP-Gag produced a 50%-reduced mortality in mice. Of note, the observed attenuation of pathogenicity did not result in either the attenuation of the humoral response against the RV G or the previously observed robust cellular response against HIV-1 Gag. These findings demonstrate that very safe and highly effective RV-based vaccines can be constructed and further emphasize their potential utility as efficacious antiviral vaccines.


2003 ◽  
Vol 77 (1) ◽  
pp. 685-695 ◽  
Author(s):  
Rongge Yang ◽  
Shigeru Kusagawa ◽  
Chiyu Zhang ◽  
Xueshan Xia ◽  
Kunlong Ben ◽  
...  

ABSTRACT We identified a new class of human immunodeficiency virus type 1 (HIV-1) recombinants (00CN-HH069 and 00CN-HH086) in which further recombination occurred between two established circulating recombinant forms (CRFs). These two isolates were found among 57 HIV-1 samples from a cohort of injecting drug users in eastern Yunnan Province of China. Informative-site analysis in conjunction with bootscanning plots and exploratory tree analysis revealed that these two strains were closely related mosaics comprised of CRF07_BC and CRF08_BC, which are found in China. The genotype screening based on gag-reverse transcriptase sequences of 57 samples from eastern Yunnan identified 47 CRF08_BC specimens (82.5%), 5 CRF07_BC specimens (8.8%), and 3 additional specimens with the novel recombinant structure. These new “second-generation” recombinants thus constitute a substantial proportion (5 of 57; 8.8%) of HIV-1 strains in this population and may belong to a new but yet-undefined class of CRF. This might be the first example of CRFs recombining with each other, leading to the evolution of second-generation inter-CRF recombinants.


2009 ◽  
Vol 53 (12) ◽  
pp. 5080-5087 ◽  
Author(s):  
Wade S. Blair ◽  
Joan Cao ◽  
Juin Fok-Seang ◽  
Paul Griffin ◽  
Jason Isaacson ◽  
...  

ABSTRACTA new small-molecule inhibitor class that targets virion maturation was identified from a human immunodeficiency virus type 1 (HIV-1) antiviral screen. PF-46396, a representative molecule, exhibits antiviral activity against HIV-1 laboratory strains and clinical isolates in T-cell lines and peripheral blood mononuclear cells (PBMCs). PF-46396 specifically inhibits the processing of capsid (CA)/spacer peptide 1 (SP1) (p25), resulting in the accumulation of CA/SP1 (p25) precursor proteins and blocked maturation of the viral core particle. Viral variants resistant to PF-46396 contain a single amino acid substitution in HIV-1 CA sequences (CAI201V), distal to the CA/SP1 cleavage site in the primary structure, which we demonstrate is sufficient to confer significant resistance to PF-46396 and 3-O-(3′,3′-dimethylsuccinyl) betulinic acid (DSB), a previously described maturation inhibitor. Conversely, a single amino substitution in SP1 (SP1A1V), which was previously associated with DSB in vitro resistance, was sufficient to confer resistance to DSB and PF-46396. Further, the CAI201V substitution restored CA/SP1 processing in HIV-1-infected cells treated with PF-46396 or DSB. Our results demonstrate that PF-46396 acts through a mechanism that is similar to DSB to inhibit the maturation of HIV-1 virions. To our knowledge, PF-46396 represents the first small-molecule HIV-1 maturation inhibitor that is distinct in chemical class from betulinic acid-derived maturation inhibitors (e.g., DSB), demonstrating that molecules of diverse chemical classes can inhibit this mechanism.


1999 ◽  
Vol 37 (3) ◽  
pp. 812-814 ◽  
Author(s):  
Donald G. Murphy ◽  
Patrick Gonin ◽  
Micheline Fauvel

We examined the reproducibility of a second-generation branched-DNA (bDNA) assay (Quantiplex HIV RNA 2.0) for quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma by retesting 325 specimens on separate runs and on different lots. The performance of the bDNA test was also assessed by data analysis obtained during routine testing of 15,365 specimens. Upon retesting, 96 and 86% of specimens displaying RNA levels above 5,000 and between 500 and 5,000 copies/ml, respectively, showed less than a 0.3 log10(twofold) difference with their initial values. Assay variability was found to increase as viral load decreased. Overall, the bDNA version 2.0 assay was found to be a reproducible and efficient test for routine quantification of HIV-1 RNA in plasma.


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