scholarly journals Antiviral Activity of Bictegravir (GS-9883), a Novel Potent HIV-1 Integrase Strand Transfer Inhibitor with an Improved Resistance Profile

2016 ◽  
pp. AAC.01474-16 ◽  
Author(s):  
Manuel Tsiang ◽  
Gregg S. Jones ◽  
Joshua Goldsmith ◽  
Andrew Mulato ◽  
Derek Hansen ◽  
...  

Bictegravir (BIC; GS-9883), a novel potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN) specifically targets IN strand transfer activity (IC50= 7.5 ± 0.3 nM) and HIV-1 integration in cells. BIC exhibits potent and selectivein vitroantiretroviral activity in both T-cell lines and primary human T-lymphocytes with EC50values ranging from 1.5 to 2.4 nM and selectivity indices up to 8800 relative to cytotoxicity. BIC exhibits synergisticin vitroantiviral effects in pairwise combinations with tenofovir alafenamide, emtricitabine or darunavir and maintains potent antiviral activity against HIV-1 variants resistant to other classes of antiretrovirals. BIC displayed anin vitroresistance profile markedly improved compared to the integrase strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), and comparable to that of dolutegravir (DTG), against nine INSTI-resistant site-directed HIV-1 mutants. BIC displayed statistically improved antiviral activity relative to EVG, RAL, and DTG against a panel of 47 patient-derived HIV-1 isolates with high-level INSTI resistance; 13 of 47 tested isolates exhibited >2-fold lower resistance to BIC compared to DTG. In dose-escalation experiments conductedin vitro, BIC and DTG exhibited higher barriers to resistance than EVG, selecting for HIV-1 variants with reduced phenotypic susceptibility at days 71, 87, and 20, respectively. A recombinant virus with the BIC-selected dual mutations M50I+R263K in IN exhibited only 2.8-fold reduced susceptibility to BIC compared to WT virus (2.8-fold). All BIC-selected variants exhibited low to intermediate level cross-resistance to RAL, DTG, and EVG (<8-fold), but remained susceptible to other classes of antiretrovirals. A high barrier toin vitroresistance emergence for both BIC and DTG was also observed in viral breakthrough studies in the presence of constant clinically relevant drug concentrations. The overall virologic profile of BIC supports its ongoing clinical investigation in combination with other antiretroviral agents for both treatment-naïve and experienced HIV-infected patients.

2007 ◽  
Vol 51 (11) ◽  
pp. 4036-4043 ◽  
Author(s):  
Serge Dandache ◽  
Guy Sévigny ◽  
Jocelyn Yelle ◽  
Brent R. Stranix ◽  
Neil Parkin ◽  
...  

ABSTRACT Despite the success of highly active antiretroviral therapy, the current emergence and spread of drug-resistant variants of human immunodeficiency virus (HIV) stress the need for new inhibitors with distinct properties. We designed, produced, and screened a library of compounds based on an original l-lysine scaffold for their potentials as HIV type 1 (HIV-1) protease inhibitors (PI). One candidate compound, PL-100, emerged as a specific and noncytotoxic PI that exhibited potent inhibition of HIV-1 protease and viral replication in vitro (Ki , ∼36 pM, and 50% effective concentration [EC50], ∼16 nM, respectively). To confirm that PL-100 possessed a favorable resistance profile, we performed a cross-resistance study using a panel of 63 viral strains from PI-experienced patients selected for the presence of primary PI mutations known to confer resistance to multiple PIs now in clinical use. The results showed that PL-100 retained excellent antiviral activity against almost all of these PI-resistant viruses and that its performance in this regard was superior to those of atazanavir, amprenavir, indinavir, lopinavir, nelfinavir, and saquinavir. In almost every case, the increase in the EC50 for PL-100 observed with viruses containing multiple mutations in protease was far less than that obtained with the other drugs tested. These data underscore the potential for PL-100 to be used in the treatment of drug-resistant HIV disease and argue for its further development.


2014 ◽  
Vol 58 (6) ◽  
pp. 3233-3244 ◽  
Author(s):  
Craig Fenwick ◽  
Ma'an Amad ◽  
Murray D. Bailey ◽  
Richard Bethell ◽  
Michael Bös ◽  
...  

ABSTRACTBI 224436 is an HIV-1 integrase inhibitor with effective antiviral activity that acts through a mechanism that is distinct from that of integrase strand transfer inhibitors (INSTIs). This 3-quinolineacetic acid derivative series was identified using an enzymatic integrase long terminal repeat (LTR) DNA 3′-processing assay. A combination of medicinal chemistry, parallel synthesis, and structure-guided drug design led to the identification of BI 224436 as a candidate for preclinical profiling. It has antiviral 50% effective concentrations (EC50s) of <15 nM against different HIV-1 laboratory strains and cellular cytotoxicity of >90 μM. BI 224436 also has a low, ∼2.1-fold decrease in antiviral potency in the presence of 50% human serum and, by virtue of a steep dose-response curve slope, exhibits serum-shifted EC95values ranging between 22 and 75 nM. Passage of virus in the presence of inhibitor selected for either A128T, A128N, or L102F primary resistance substitutions, all mapping to a conserved allosteric pocket on the catalytic core of integrase. BI 224436 also retains full antiviral activity against recombinant viruses encoding INSTI resistance substitutions N155S, Q148H, and E92Q. In drug combination studies performed in cellular antiviral assays, BI 224436 displays an additive effect in combination with most approved antiretrovirals, including INSTIs. BI 224436 has drug-likein vitroabsorption, distribution, metabolism, and excretion (ADME) properties, including Caco-2 cell permeability, solubility, and low cytochrome P450 inhibition. It exhibited excellent pharmacokinetic profiles in rat (clearance as a percentage of hepatic flow [CL], 0.7%; bioavailability [F], 54%), monkey (CL, 23%;F, 82%), and dog (CL, 8%;F, 81%). Based on the excellent biological and pharmacokinetic profile, BI 224436 was advanced into phase 1 clinical trials.


2006 ◽  
Vol 80 (14) ◽  
pp. 6883-6894 ◽  
Author(s):  
S. Kehlenbeck ◽  
U. Betz ◽  
A. Birkmann ◽  
B. Fast ◽  
A. H. Göller ◽  
...  

ABSTRACT We have identified dihydroxythiophenes (DHT) as a novel series of human immunodeficiency virus type 1 (HIV-1) integrase inhibitors with broad antiviral activities against different HIV isolates in vitro. DHT were discovered in a biochemical integrase high-throughput screen searching for inhibitors of the strand transfer reaction of HIV-1 integrase. DHT are selective inhibitors of integrase that do not interfere with virus entry, as shown by the inhibition of a vesicular stomatitis virus G-pseudotyped retroviral system. Moreover, in quantitative real-time PCR experiments, no effect on the synthesis of viral cDNA could be detected but rather an increase in the accumulation of 2-long-terminal-repeat cycles was detected. This suggests that the integration of viral cDNA is blocked. Molecular modeling and the structure activity relationship of DHT demonstrate that our compound fits into a two-metal-binding motif that has been suggested as the essential pharmacophore for diketo acid (DKA)-like strand transfer inhibitors (Grobler et al., Proc. Natl. Acad. Sci. USA 99:6661-6666, 2002.). This notion is supported by the profiling of DHT on retroviral vectors carrying published resistance mutations for DKA-like inhibitors where DHT showed partial cross-resistance. This suggests that DHT bind to a common site in the catalytic center of integrase, albeit with an altered binding mode. Taken together, our findings indicate that DHT are novel selective strand transfer inhibitors of integrase with a pharmacophore homologous to DKA-like inhibitors.


2011 ◽  
Vol 55 (4) ◽  
pp. 1366-1376 ◽  
Author(s):  
Christian Callebaut ◽  
Kirsten Stray ◽  
Luong Tsai ◽  
Matt Williams ◽  
Zheng-Yu Yang ◽  
...  

ABSTRACTGS-8374 is a novel bis-tetrahydrofuran HIV-1 protease (PR) inhibitor (PI) with a unique diethylphosphonate moiety. It was selected from a series of analogs containing various di(alkyl)phosphonate substitutions connected via a linker to theparaposition of a P-1 phenyl ring. GS-8374 inhibits HIV-1 PR with high potency (Ki= 8.1 pM) and with no known effect on host proteases. Kinetic and thermodynamic analysis of GS-8374 binding to PR demonstrated an extremely slow off rate for the inhibitor and favorable contributions of both the enthalpic and entropic components to the total free binding energy. GS-8374 showed potent antiretroviral activity in T-cell lines, primary CD4+T cells (50% effective concentration [EC50] = 3.4 to 11.5 nM), and macrophages (EC50= 25.5 nM) and exhibited low cytotoxicity in multiple human cell types. The antiviral potency of GS-8374 was only moderately affected by human serum protein binding, and its combination with multiple approved antiretrovirals showed synergistic effects. When it was tested in a PhenoSense assay against a panel of 24 patient-derived viruses with high-level PI resistance, GS-8374 showed lower mean EC50s and lower fold resistance than any of the clinically approved PIs. Similar to other PIs,in vitrohepatic microsomal metabolism of GS-8374 was efficiently blocked by ritonavir, suggesting a potential for effective pharmacokinetic boostingin vivo. In summary, results from this broadin vitropharmacological profiling indicate that GS-8374 is a promising candidate to be further assessed as a new antiretroviral agent with potential for clinical efficacy in both treatment-naïve and -experienced patients.


2010 ◽  
Vol 55 (1) ◽  
pp. 321-325 ◽  
Author(s):  
L. Van Wesenbeeck ◽  
E. Rondelez ◽  
M. Feyaerts ◽  
A. Verheyen ◽  
K. Van der Borght ◽  
...  

ABSTRACTThe integrase inhibitor raltegravir (RAL) is currently used for the treatment of both treatment-naïve and treatment-experienced HIV-1-infected patients. Elvitegravir (EVG) is in late phases of clinical development. Since significant cross-resistance between RAL and EVG is observed, there is a need for second-generation integrase inhibitors (INIs) with a higher genetic barrier and limited cross-resistance to RAL/EVG. A panel of HIV-1 integrase recombinants, derived from plasma samples from raltegravir-treated patients (baseline and follow-up samples), were used to study the cross-resistance profile of two second-generation integrase inhibitors, MK-2048 and compound G. Samples with Q148H/R mutations had elevated fold change values with all compounds tested. Although samples with the Y143R/C mutation had reduced susceptibility to RAL, they remained susceptible to MK-2048 and compound G. Samples with the N155H mutation had no reduced susceptibility to compound G. In conclusion, our results allowed ranking of the INIs on the basis of the antiviral activities using recombinant virus stocks from RAL-treated patient viruses. The order according to decreasing susceptibility is compound G, MK-2048, and EVG.


2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Steven J. Smith ◽  
Xue Zhi Zhao ◽  
Dario Oliveira Passos ◽  
Dmitry Lyumkis ◽  
Terrence R. Burke ◽  
...  

ABSTRACT The currently recommended first-line therapy for HIV-1-infected patients is an integrase (IN) strand transfer inhibitor (INSTI), either dolutegravir (DTG) or bictegravir (BIC), in combination with two nucleoside reverse transcriptase inhibitors (NRTIs). Both DTG and BIC potently inhibit most INSTI-resistant IN mutants selected by the INSTIs raltegravir (RAL) and elvitegravir (EVG). BIC has not been reported to select for resistance in treatment-naive patients, and DTG has selected for a small number of resistant viruses in treatment-naive patients. However, some patients who had viruses with substitutions selected by RAL and EVG responded poorly when switched to DTG-based therapies, and there are mutants that cause a considerable decrease in the potencies of DTG and BIC in in vitro assays. The new INSTI cabotegravir (CAB), which is in late-stage clinical trials, has been shown to select for novel resistant mutants in vitro. Thus, it is important to develop new and improved INSTIs that are effective against all the known resistant mutants. This led us to test our best inhibitors, in parallel with DTG, BIC, and CAB, in a single-round infection assay against a panel of the new CAB-resistant mutants. Of the INSTIs we tested, BIC and our compound 4d had the broadest efficacy. Both were superior to DTG, as evidenced by the data obtained with the IN mutant T66I/L74M/E138K/S147G/Q148R/S230N, which was selected by CAB using an EVG-resistant lab strain. These results support the preclinical development of compound 4d and provide information that can be used in the design of additional INSTIs that will be effective against a broad spectrum of resistant mutants.


2019 ◽  
Author(s):  
Aniqa Shahid ◽  
Wendy W. Zhang ◽  
Vincent Montoya ◽  
Peter K. Cheung ◽  
Natalia Oliveira ◽  
...  

ABSTRACTPhenotypic resistance data is relatively sparse for the newest HIV-1 integrase strand transfer inhibitors (INSTIs), dolutegravir (DTG), bictegravir (BIC), and cabotegravir (CAB). In this study, we report the phenotypic susceptibility of a large panel of oligo-clonal patient-derived HIV-1 integrase viruses. Representative clinical samples (N=141) were selected from a large database (N=17,197) of clinically-derived HIV integrase sequences, based on the presence of permutations of substitutions at 27 pre-defined positions in integrase (N=288). HIV-1 RNA was extracted from patient samples and diluted to approximately 500 HIV RNA copies/mL. Using an “oligo-clonal” amplification approach to achieve single-copy amplification, these dilutions were subjected to 12 parallel RT-PCR reactions to amplify integrase. Confirmed clonal amplicons were co-transfected with linearized pNL4.3∆int into CEM-GXR cells. In total, 162 HIV-1 viruses that carried no mixtures and had a unique sequence were harvested, and phenotyped in MT4-LTR-EGFP cells subsequently. Variants with the highest fold change (FC) had G140S and Q148R/H and resistant to all five drugs; R263K was the only single variant conferring >3-FC to DTG, BIC and CAB. There was extensive cross-resistance between DTG, BIC, and CAB and phenotypic resistance values for all the three INSTIs were almost collinear. The greatest exceptions were variants with N155H/G163E or L74I/T97M/F121C/V151I/E157Q/G163K, where both had >70-FC for CAB, while <3-FC for DTG and BIC. While site-directed mutagenesis is invaluable; the systematic selection of representative mutational patterns observedin vivoprovides an efficient way to identify clinically relevant drug resistance.


2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Francesco Saladini ◽  
Alessia Giannini ◽  
Adele Boccuto ◽  
Filippo Dragoni ◽  
Alice Appendino ◽  
...  

ABSTRACT Second-generation HIV-1 integrase strand transfer inhibitors (INSTIs) dolutegravir (DTG), bictegravir (BIC), and cabotegravir (CAB) showed a high genetic barrier to resistance and limited cross-resistance with first-generation INSTIs raltegravir (RAL) and elvitegravir (EVG). In this study, DTG, BIC, and CAB demonstrated a comparable activity on a panel of INSTI-resistant strains isolated from patients exposed to RAL, EVG, and/or DTG, with a significantly reduced susceptibility only with the pathway Q148H/K/R plus one to two additional INSTI mutations.


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