HIV integrase strand transfer (IC50 = 2.7 nM)

Dolutegravir (S/GSK1349572) has an EC50 of 0.51 nM against HIV-1 in PBMCs, 0.71 nM in MT-4 cells, and 2.2 nM in the pseudotyped self-inactivating virus (PHIV) assay. Dolutegravir's 50% cytotoxic concentrations (CC50) in proliferating IM-9, U-937, MT-4, and Molt-4 cells are, in order, 4.8, 7.0, 14, and 15 μM. The CC50 values in unstimulated and stimulated PBMCs are 189 μM and 52 μM, in that order. Dolutegravir's 0.51 nM EC50 against HIV-1 in PBMCs indicates that a cell-based therapeutic index of at least 9,400 is required[1].

In rats (0.23 mL/min/kg) and monkeys (2.12 mL/min/kg), the plasma clearance after a single intravenous (IV) dose of dolutegravir is low. Both the rat and monkey have half-lives of roughly six hours, and their steady-state volume of distribution (VSS) is small. When given orally as a solution to one male monkey and five fast-fasting rats, dolutegravir is highly bioavailable and quickly absorbed (75.6 and 87.0%, respectively). After oral administration of a suspension to non-fasted rats up to 250 mg/kg and non-fasted monkeys up to 50 mg/kg, dolutegravir exposure (Cmax and AUC) increased with increasing dose, however the rise is less than proportional[3].

In vitro strand transfer assay. The inhibitory potencies of S/GSK1349572 and other INIs were measured in a strand transfer assay using recombinant HIV integrase as previously described (5). A complex of integrase and biotinylated preprocessed donor DNA-streptavidin-coated Acintillation proximity assay (SPA) beads was formed by incubating 2 μM purified recombinant integrase with 0.66 μM biotinylated donor DNA-4 mg/ml streptavidin-coated SPA beads in 25 mM sodium morpholinepropanesulfonic acid (MOPS) (pH 7.2), 23 mM NaCl, and 10 mM MgCl2 for 5 min at 37°C. These beads were spun down and preincubated with diluted INIs for 60 min at 37°C. Then a 3H-labeled target DNA substrate was added to give a final concentration of 7 nM substrate, and the strand transfer reaction mixture was incubated at 37°C for 25 to 45 min, which allowed for a linear increase in the strand transfer of donor DNA to radiolabeled target DNA. The signal was read using a Wallac MicroBeta scintillation plate reader [1].

Antiviral assay in MT-4 cells.[1]
MT-4 cells growing exponentially at a density of 5 × 105 or 6 × 105/ml were infected with HIV-1 strain IIIB at a viral multiplicity of infection of 0.001 or a 50% tissue culture infective dose of 4 to 10. The cells were then aliquoted to 96-well plates in the presence of varying concentrations of compounds. After incubation for 4 or 5 days, antiviral activity was determined by a cell viability assay that either measured bioluminescence with a CellTiter-Glo luminescent reagent or measured absorbance at 560 and 690 nm using the yellow tetrazolium MTT reagent [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide].

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Antiviral assay in PBMCs.[1]
In one 96-well culture plate, PHA- and IL-2-stimulated PBMCs (4 × 105/well) were preincubated with a compound for 1 h, while HIV-1 strain Ba-L was mixed with the same compound in a second plate. An aliquot of the Ba-L-compound mixture was then transferred to the PBMC-compound mixture and was incubated for 7 days. After this incubation, supernatants were assayed for reverse transcriptase (RT) activity by incorporation of [methyl-3H]dTTP to measure viral replication as previously described.

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Cytotoxicity assays.[1]
In vitro growth inhibition (cytotoxicity) studies were conducted with S/GSK1349572 in proliferating human leukemic and lymphomic cell lines (IM-9, U-937, MT-4, and Molt-4) as well as in stimulated and unstimulated human PBMCs. ATP levels were quantified by using the CellTiter-Glo luciferase reagent to measure the ability of a compound to inhibit cell growth as an indicator of the compound's potential for cytotoxicity.

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Mechanistic cellular studies.[1]
To determine if S/GSK1349572 was inhibiting HIV replication in cellular assays through an integrase inhibition mechanism, the effects on the synthesis of HIV NL432 DNA species in MT-4 cells were measured in a single-round infection assay using quantitative PCR methods. Quantitative PCR analysis was performed to measure the synthesis of HIV DNA species in MT-4 cells in the presence of an INI or NNRTI as described previously, with minor modifications. Briefly, 293T cells were transfected with the NL432 plasmid to generate infectious virus, and the supernatant was filtered through 0.45-μm-pore-size filters and was treated with DNase I. MT-4 cells were infected with HIV-1 NL432 for 1 h, incubated with dilutions of a compound, and collected after 6 or 18 h of incubation. All cells were incubated with 0.5 μM ritonavir in order to limit HIV replication to a single cycle. Total-DNA PCR to detect late RT products was performed by incubating the samples for 6 h. Nested Alu-PCR to detect integrated provirus and 2-LTR PCR to detect 2-LTR circles were performed by incubating the samples for 18 h. Reaction products were analyzed using the ABI Prism 7900HT-3 sequence detection system

For rat and monkey PK studies, Dolutegravir is administered as the free acid or the sodium salt. All doses are presented in terms of the free acid. Dolutegravir is administered by intravenous (IV) short-term (within 2 min) bolus (1 mg/kg) to three male rats and two male monkeys. For single oral administration, Dolutegravir as a solution (5 mg/kg) is administered to three fasted male rats and two fasted male monkeys. Dolutegravir is administered as single oral doses of 5, 50, 100, and 250 mg/kg to non-fasted male rats (n=2/dose level) and 3, 10, and 50 mg/kg to non-fasted female monkeys. For intravenous administration, blood samples are collected from rats (0.2 mL via jugular vein cannula) and monkeys (approximately 0.2 or 0.5 mL via saphenous vein in a hindlimb) into Na2EDTA-treated syringes at 0.083, 0.25, 0.5, 1, 2, 4, 6, 8, and 24 h. For oral administration, samples are collected at 0.25 (rats only), 0.5, 1, 2, 4, 6 [rats (solution and suspension) and monkey (solution only)], 8, and 24 h. Following collection, the blood is immediately put on wet ice and then centrifuged within an hour at 1740 g for 10 min at 4°C to obtain plasma. All samples are stored at approximately -20°C or colder prior to analysis by using a method based on protein precipitation and LC-MS/MS analysis.[1]

2.7 mg/kg/day; administrated orally for two weeks.

C57BL/6 mice

Absorption, Distribution and Excretion
When 50 mg of dolutegravir once daily was orally administered to HIV-1 infected adults, the AUC, Cmax, and Cmin is 53.6 mcg h/mL, 3.67 mcg/mL, and 1.11 mcg/mL, respectively. The peak plasma concentration was observed 2 to 3 hours post-dose. Steady state is achieved within approximately 5 days with average accumulation ratios for AUC, Cmax, and C24h ranging from 1.2 to 1.5. When 50 mg once daily is given to pediatric patients (12 to < 18 years and weighing ≥40 kg) the Cmax, AUC, and C24 is 3.49 mcg/mL, 46 mcg.h/mL, and 0.90 mcg/mL respectively.
When a single oral dose of dolutegravir is given, nearly all complete dose is recovered in a proportion of 53% excreted unchanged in the feces and 31% excreted in urine. The renal eliminated recovered dose consists of ether glucuronide of dolutegravir (18.9%), a metabolite formed by oxidation at the benzylic carbon (3.0%), a hydrolytic N-dealkylation product (3.6%) and unchanged drug (< 1%).
The administration of a dose of 50 mg of dolutegravir presents an apparent volume of distribution of 17.4 L. The median dolutegravir concentration in CSF was 18 ng/mL after 2 weeks of treatment.
The apparent clearance rate of dultegravir is 1.0 L/h.
... After a single oral dose of [14C] dolutegravir, 53% of the total oral dose was excreted unchanged in feces. Thirty-one percent of the total oral dose was excreted in urine, represented by an ether glucuronide of dolutegravir (18.9% of total dose), a metabolite formed by oxidation at the benzylic carbon (3.0% of total dose), and its hydrolytic N-dealkylation product (3.6% of total dose). Renal elimination of unchanged drug was low (<1% of the dose).
Dolutegravir is highly bound (=98.9%) to human plasma proteins based on in vivo data and binding is independent of plasma concentration of dolutegravir. The apparent volume of distribution (Vd/F) following 50-mg once-daily administration is estimated at 17.4 L based on a population pharmacokinetic analysis.
Food increased the extent of absorption and slowed the rate of absorption of dolutegravir. Low-, moderate-, and high-fat meals increased dolutegravir AUC(0-8) by 33%, 41%, and 66%; increased Cmax by 46%, 52%, and 67%; and prolonged Tmax to 3, 4, and 5 hours from 2 hours under fasted conditions, respectively.
Following oral administration of dolutegravir, peak plasma concentrations were observed 2 to 3 hours postdose. With once-daily dosing, pharmacokinetic steady state is achieved within approximately 5 days with average accumulation ratios for AUC, Cmax, and C24 h ranging from 1.2 to 1.5. Dolutegravir plasma concentrations increased in a less than dose-proportional manner above 50 mg. Dolutegravir is a P-glycoprotein substrate in vitro. The absolute bioavailability of dolutegravir has not been established.

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Metabolism / Metabolites
Dolutegravir is highly metabolized through three main pathways and it forms no long-lived metabolites. The first pathway is defined by the glucuronidation by UGT1A1, the second pathway by carbon oxidation by CYP3A4 and the third pathway is what appears to be a sequential oxidative defluorination and glutathione conjugation. The main metabolite found in blood plasma is the ether glucuronide form (M2) and its chemical properties disrupt its ability to bind metal ions, therefore, it is inactive.
Dolutegravir is primarily metabolized via UGT1A1 with some contribution from CYP3A. ... ether glucuronide of dolutegravir (18.9% of total dose), a metabolite formed by oxidation at the benzylic carbon (3.0% of total dose), and its hydrolytic N-dealkylation product (3.6% of total dose). ...

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Biological Half-Life
The half-life of dolutegravir is 14 hours.
Dolutegravir has a terminal half-life of approximately 14 hours and an apparent clearance (CL/F) of 1.0 L/h based on population pharmacokinetic analyses.

Interactions
Dolutegravir is metabolized by UGT1A1 with some contribution from CYP3A. Dolutegravir is also a substrate of UGT1A3, UGT1A9, BCRP, and P-gp in vitro. Drugs that induce those enzymes and transporters may decrease dolutegravir plasma concentration and reduce the therapeutic effect of dolutegravir. Coadministration of dolutegravir and other drugs that inhibit these enzymes may increase dolutegravir plasma concentration. Etravirine significantly reduced plasma concentrations of dolutegravir, but the effect of etravirine was mitigated by coadministration of lopinavir/ritonavir or darunavir/ritonavir, and is expected to be mitigated by atazanavir/ritonavir. Darunavir/ritonavir, lopinavir/ritonavir, rilpivirine, tenofovir, boceprevir, telaprevir, prednisone, rifabutin, and omeprazole had no clinically significant effect on the pharmacokinetics of dolutegravir.
Coadministration of TIVICAY with dofetilide is contraindicated due to the potential for increased dofetilide plasma concentrations and the risk for serious and/or life-threatening events

[1]. Kobayashi M, et al. In Vitro antiretroviral properties of S/GSK1349572, a next-generation HIV integrase inhibitor. Antimicrob Agents Chemother. 2011 Feb;55(2):813-21.
[2]. Hare S, et al. Structural and functional analyses of the second-generation integrase strand transfer inhibitor dolutegravir (S/GSK1349572). Mol Pharmacol. 2011 Oct;80(4):565-72.
[3]. Moss L, et al. The comparative disposition and metabolism of dolutegravir, a potent HIV-1 integrase inhibitor, in mice, rats, and monkeys. Xenobiotica. 2015 Jan;45(1):60-70

Therapeutic Uses
HIV Integrase Inhibitors
The recommended dose of TIVICAY in pediatric patients aged 12 years and older and weighing at least 40 kg is 50 mg administered orally once daily. If efavirenz, fosamprenavir/ritonavir, tipranavir/ritonavir, or rifampin are coadministered, the recommended dose of TIVICAY is 50 mg twice daily. Safety and efficacy of TIVICAY have not been established in pediatric patients younger than 12 years or weighing less than 40 kg, or in pediatric patients who are INSTI-experienced with documented or clinically suspected resistance to other INSTIs (raltegravir, elvitegravir).
TIVICAY (dolutegravir) is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults and children aged 12 years and older and weighing at least 40 kg. The following should be considered prior to initiating treatment with TIVICAY: Poor virologic response was observed in subjects treated with TIVICAY 50 mg twice daily with an integrase strand transfer inhibitor (INSTI)-resistance Q148 substitution plus 2 or more additional INSTI-resistance substitutions, including L74I/M, E138A/D/K/T, G140A/S, Y143H/R, E157Q, G163E/K/Q/R/S, or G193E/R.
Renal clearance of unchanged drug is a minor pathway of elimination for dolutegravir. In a trial comparing 8 subjects with severe renal impairment (CrCl <30 mL/min) with 8 matched healthy controls, AUC, Cmax, and C24 of dolutegravir were decreased by 40%, 23%, and 43%, respectively, compared with those in matched healthy subjects. The cause of this decrease is unknown. Population pharmacokinetic analysis using data from SAILING and VIKING-3 trials indicated that mild and moderate renal impairment had no clinically relevant effect on the exposure of dolutegravir. No dosage adjustment is necessary for treatment-naive or treatment-experienced and INSTI-naive patients with mild, moderate, or severe renal impairment or for INSTI-experienced patients (with certain INSTI-associated resistance substitutions or clinically suspected INSTI resistance) with mild or moderate renal impairment. Caution is warranted for INSTI-experienced patients (with certain INSTI-associated resistance substitutions or clinically suspected INSTI resistance [see Microbiology (12.4)]) with severe renal impairment, as the decrease in dolutegravir concentrations may result in loss of therapeutic effect and development of resistance to TIVICAY or other coadministered antiretroviral agents. Dolutegravir has not been studied in patients requiring dialysis.
Dolutegravir is primarily metabolized and eliminated by the liver. In a trial comparing 8 subjects with moderate hepatic impairment (Child-Pugh Score B) with 8 matched healthy controls, exposure of dolutegravir from a single 50-mg dose was similar between the 2 groups. No dosage adjustment is necessary for patients with mild to moderate hepatic impairment (Child-Pugh Score A or B). The effect of severe hepatic impairment (Child-Pugh Score C) on the pharmacokinetics of dolutegravir has not been studied. Therefore, TIVICAY is not recommended for use in patients with severe hepatic impairment.

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Drug Warnings
The Centers for Disease Control and Prevention recommend that HIV-1-infected mothers in the United States not breastfeed their infants to avoid risking postnatal transmission of HIV-1 infection. Studies in lactating rats and their offspring indicate that dolutegravir was present in rat milk. It is not known whether dolutegravir is excreted in human milk. Because of both the potential for HIV transmission and the potential for adverse reactions in nursing infants, mothers should be instructed not to breastfeed if they are receiving TIVICAY.
Pregnancy Category B. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, and dolutegravir was shown to cross the placenta in animal studies, this drug should be used during pregnancy only if clearly needed.
Dolutegravir (TIVICAY) should not be used with etravirine without coadministration of atazanavir/ritonavir, darunavir/ritonavir, or lopinavir/ritonavir.
Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including TIVICAY. During the initial phase of combination antiretroviral treatment, patients whose immune systems respond may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia (PCP), or tuberculosis), which may necessitate further evaluation and treatment. Autoimmune disorders (such as Graves' disease, polymyositis, and Guillain-Barre syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable and can occur many months after initiation of treatment.
For more Drug Warnings (Complete) data for Dolutegravir (8 total), please visit the HSDB record page.

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Pharmacodynamics
HIV-1 infected subjects on dolutegravir monotherapy demonstrated rapid and dose-dependent reduction of antiviral activity with declines of HIV-1 RNA copies per ml. The antiviral response was maintained for 3 to 4 days after the last dose. The sustained response obtained in clinical trials indicates that dolutegravir has a tight binding and longer dissociative half-life providing it a high barrier to resistance. The combination therapy (ripivirine and dolutegravir) presented the same viral suppression found in previous three-drug therapies without integrase strand transfer inhibitor mutations or rilpivirine resistance.

C20H19F2N3O5

419.38

419.129

C, 57.28; H, 4.57; F, 9.06; N, 10.02; O, 19.08

1051375-16-6

Dolutegravir sodium;1051375-19-9;Cabotegravir;1051375-10-0;Dolutegravir-d3;Dolutegravir-d5;2249814-82-0

54726191

White to off-white solid

1.53 g/cm3

669.0±55.0 °C at 760 mmHg

190-193ºC

358.4±31.5 °C

0.0±2.1 mmHg at 25°C

1.650

-1.32

2

8

3

30

829

2

FC1=CC(F)=C(C=C1)CNC(C2=CN(C3=C(C2=O)O)C[C@@]([H])(N4C3=O)OCC[C@H]4C)=O

RHWKPHLQXYSBKR-BMIGLBTASA-N

InChI=1S/C20H19F2N3O5/c1-10-4-5-30-15-9-24-8-13(17(26)18(27)16(24)20(29)25(10)15)19(28)23-7-11-2-3-12(21)6-14(11)22/h2-3,6,8,10,15,27H,4-5,7,9H2,1H3,(H,23,28)/t10-,15+/m1/s1

(4R,12aS)-N-(2,4-difluorobenzyl)-7-hydroxy-4-methyl-6,8-dioxo-3,4,6,8,12,12a-hexahydro-2H-pyrido[1',2':4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.62 mg/mL (6.25 mM) (saturation unknown) in 5% DMSO + 95% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.96 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.96 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 4: ≥ 2.5 mg/mL (5.96 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)