HIV

Fostemsavir(BMS-663068) is a prodrug of the small-molecule inhibitor Temsavir/BMS-626529, which inhibits human immunodeficiency virus type 1 (HIV-1) infection by binding to gp120 and interfering with the attachment of virus to CD4+ T-cells.The activity of BMS-626529 is virus dependent, due to heterogeneity within gp120. In order to better understand the anti-HIV-1 spectrum of BMS-626529 against HIV-1, in vitro activities against a wide variety of laboratory strains and clinical isolates were determined. BMS-626529 had half-maximal effective concentration (EC(50)) values of <10 nM against the vast majority of viral isolates; however, susceptibility varied by >6 log(10), with half-maximal effective concentration values in the low pM range against the most susceptible viruses. The in vitro antiviral activity of BMS-626529 was generally not associated with either tropism or subtype, with few exceptions. Measurement of the binding affinity of BMS-626529 for purified gp120 suggests that a contributory factor to its inhibitory potency may be a relatively long dissociative half-life. Finally, in two-drug combination studies, BMS-626529 demonstrated additive or synergistic interactions with antiretroviral drugs of different mechanistic classes. These results suggest that BMS-626529 should be active against the majority of HIV-1 viruses and support the continued clinical development of the compound.[1]

Fostemsavir Tris exhibits good antiviral action (IC50, <100 nM) against drug-susceptible viruses in infected patients [1].

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The maximum median decrease in plasma HIV-1 RNA load from baseline ranged from 1.21 to 1.73 log(10) copies/mL. Plasma concentrations of BMS-626529 were not associated with an antiviral response, while low baseline inhibitory concentrations and the minimum and average steady-state BMS-626529 plasma concentrations, when adjusted by the baseline protein binding-adjusted 90% inhibitory concentration (inhibitory quotient), were linked with antiviral response. BMS-663068 was generally well tolerated. Conclusions: Administration of BMS-663068 for 8 days with or without ritonavir resulted in substantial declines in plasma HIV-1 RNA levels and was generally well tolerated. Longer-term clinical trials of BMS-663068 as part of combination antiretroviral therapy are warranted. Clinical Trials Registration.NCT01009814. [J Infect Dis. 2012 Oct 1;206(7):1002-11]

The maximum median decrease in plasma HIV-1 RNA load from baseline ranged from 1.21 to 1.73 log(10) copies/mL. Plasma concentrations of BMS-626529 were not associated with an antiviral response, while low baseline inhibitory concentrations and the minimum and average steady-state BMS-626529 plasma concentrations, when adjusted by the baseline protein binding-adjusted 90% inhibitory concentration (inhibitory quotient), were linked with antiviral response. BMS-663068 was generally well tolerated. Conclusions: Administration of BMS-663068 for 8 days with or without ritonavir resulted in substantial declines in plasma HIV-1 RNA levels and was generally well tolerated. Longer-term clinical trials of BMS-663068 as part of combination antiretroviral therapy are warranted. Clinical Trials Registration.NCT01009814.[J Infect Dis . 2012 Oct 1;206(7):1002-11]

Cytotoxicity assays. [1]
Cytotoxicity assays were performed in the presence of serially diluted BMS-626529 for up to 6 days, and cell viability was quantitated using an XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) assay. To determine CC50 values (concentration of drug required to kill 50% of cells), laboratory-adapted cells were initially plated at a density of 0.1 × 106 cells/ml. In the absence of compounds, the cell densities typically reached 1.0 × 106 to 1.2 × 106/ml after 6 days.

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Drug susceptibility assays using laboratory virus strains. [1]
MT-2 (for CXCR4 or dual-tropic viruses) or PM1 (for CCR5-tropic viruses) cells were infected with virus at a multiplicity of infection of 0.005 and incubated in the presence of serial dilutions of drug at 37°C for 4 to 6 days. Virus yields were quantified by determination of reverse transcriptase (RT) activity for CXCR4 viruses or by a p24 enzyme-linked immunosorbent assay for CCR5 viruses.

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Drug susceptibility assays using clinical isolates. [1]
Pellets of PBMCs were infected with clinical isolates at a multiplicity of infection of 0.005 and incubated in a 0.5-ml volume at 37°C for 3 h prior to resuspension in medium and addition to plates containing serial dilutions of drug. The final cell density was 1 × 106 cells/ml. Plates were incubated at 37°C, and virus yields were monitored from day 5 postinfection by using a p24 ELISA kit according to the manufacturer's instructions. The incubation was terminated when the control infection yielded a level of p24 in the supernatant within a dynamic range (0.6 < A490 < 2.0).

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Drug susceptibility assays using envelopes derived from clinical isolates. [1]
Plasma samples obtained during Bristol-Myers Squibb-sponsored trials were tested by Monogram Biosciences, together with additional samples from the Monogram collection. Drug susceptibilities of the envelopes were determined using the PhenoSense Entry assay. Envelope sequences (gp160) were amplified by reverse transcriptase PCR (RT-PCR) and ligated into the pCXAS expression vector. Envelope expression vectors were prepared as large pools of sequences (>200) in order to ensure an accurate representation of the diversity of viral quasispecies present in each sample. Recombinant HIV-1 pseudovirus stocks were prepared by cotransfecting HEK293 cells with the envelope expression vectors and a replication-defective HIV-1 genomic vector containing luciferase within the deleted envelope region. Recombinant pseudovirus particles were used to infect U87 cell lines expressing CD4/CCR5/CXCR4. Drug susceptibility was measured by comparison of luciferase activities in the presence and absence of BMS-626529. Drug susceptibility data were provided as half-maximal inhibitory concentration (IC50) values by Monogram Biosciences and are reported as such.

Fifty HIV-1-infected subjects were randomized to 1 of 5 regimen groups (600 mg BMS-663068 plus 100 mg ritonavir every 12 hours [Q12H], 1200 mg BMS-663068 plus 100 mg ritonavir every bedtime, 1200 mg BMS-663068 plus 100 mg ritonavir Q12H, 1200 mg BMS-663068 Q12H plus 100 mg ritonavir every morning, or 1200 mg BMS-663068 Q12H) for 8 days in this open-label, multiple-dose, parallel study. The study assessed the pharmacodynamics, pharmacokinetics, and safety of BMS-663068.[J Infect Dis. 2012 Oct 1;206(7):1002-11.]

Absorption
After oral administration, the absorption of temsavir is mainly limited by its poor solubility. The phosphonomethyl prodrug of temsavir, fostesavir, has higher water solubility and stability under acidic conditions compared to the parent drug. The absolute bioavailability of fostesavir after oral administration is approximately 26.9%. After twice-daily oral administration of 600 mg fostesavir, its Cmax and AUCtau are 1770 ng/mL and 12900 ng·h/L, respectively, with a Tmax of approximately 2 hours. Co-administration with a standard meal increases the AUC of fostesavir by approximately 10%, while co-administration with a high-fat meal increases it by approximately 81%.
Excretion
Temsavir is rapidly metabolized and is mainly excreted in the urine and feces as inactive metabolites. Approximately 51% of the administered dose is excreted in the urine, of which less than 2% is the unchanged drug; 33% is excreted in the feces, of which 1.1% is the unchanged drug.
Volume of Distribution
The steady-state volume of distribution of temsavir after intravenous injection is approximately 29.5 L.
Clearance
The mean and apparent clearance of temsavir (the active metabolite of fostesavir) are 17.9 L/h and 66.4 L/h, respectively.

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Metabolites/Metabolites
Fostesavir is rapidly hydrolyzed to its active metabolite, temsavir, by alkaline phosphatase on the brush border membrane of the intestinal lumen. Temsavir is further bioconverted into two major inactive metabolites: the esterase hydrolysis product BMS-646915 and the N-dealkylated metabolite BMS-930644 generated by CYP3A4 oxidation. After oral administration, approximately 36.1% of the drug is metabolized by esterases, 21.2% by CYP3A4, and less than 1% is bound by UDP-glucuronyltransferase (UGT) before being cleared. Temsavir and its two main metabolites are known to inhibit BCRP.

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Biological half-life
The half-life of temsavir is approximately 11 hours. After oral administration, temsavir is usually undetectable in plasma.

Effects During Pregnancy and Lactation
◉ Overview of Drug Use During Lactation
There is currently no information regarding the use of Fostersavir during lactation. Because this drug and its active metabolite, temsavir, have a protein binding rate exceeding 80%, their levels in breast milk are likely to be very low. Achieving and maintaining viral suppression through antiretroviral therapy can reduce the risk of breast milk transmission to below 1%, but not zero. This decision should be supported for HIV-infected individuals receiving antiretroviral therapy with a persistently low viral load who choose to breastfeed. If viral load is not suppressed, pasteurized donor breast milk or formula is recommended.
◉ Effects on Breastfed Infants
No published information found as of the revision date.
◉ Effects on Lactation and Breast Milk
No published information found as of the revision date.

[1]. In vitro antiviral characteristics of HIV-1 attachment inhibitor BMS-626529, the active component of the prodrug BMS-663068. Antimicrob Agents Chemother. 2012 Jul;56(7):3498-507.

Fostemsavir (brand name: Rukobia) is a prescription drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of previously treated adults with HIV who meet specific criteria, determined by their healthcare provider. Fostemsavir must be used in combination with other HIV medications. Fostemsavir tromethamine is the tromethamine salt form of Fostemsavir, a highly bioavailable oral phosphonomethyl prodrug that is the active ingredient of temsavir, an HIV-1 attachment inhibitor, and possesses anti-HIV activity. After oral administration, Fostemsavir is hydrolyzed to the active ingredient temsavir. Temsavir targets and binds to the gp120 subunit of the HIV-1 envelope glycoprotein gp160. This selectively inhibits the interaction between HIV-1 and the host cell CD4 receptor, thereby preventing HIV-1 attachment. This also inhibits the gp120-dependent post-attachment step required for HIV-1 to enter host cells.

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Drug Indications
Rukobia, in combination with other antiretroviral drugs, is indicated for the treatment of adult patients with multidrug-resistant HIV-1 infection for whom a suppressive antiviral regimen cannot be constructed.

C29H37N8O11P

704.6248

704.231

C, 49.43; H, 5.29; N, 15.90; O, 24.98; P, 4.40

864953-39-9

Temsavir;701213-36-7; 864953-29-7(free base); 864953-39-9 (tromethamine) ; 864953-31-1 (disodium); 942117-71-7 (dihydrate)

46892186

White to off-white solid powder

6

15

11

49

1070

0

O=C(C1C2C(=C(N3C=NC(C)=N3)N=CC=2OC)N(COP(O)(O)=O)C=1)C(N1CCN(C(C2C=CC=CC=2)=O)CC1)=O.OCC(CO)(CO)N

RRGJSMBMTOKHTE-UHFFFAOYSA-N

InChI=1S/C25H26N7O8P.C4H11NO3/c1-16-27-14-32(28-16)23-21-20(19(39-2)12-26-23)18(13-31(21)15-40-41(36,37)38)22(33)25(35)30-10-8-29(9-11-30)24(34)17-6-4-3-5-7-17;5-4(1-6,2-7)3-8/h3-7,12-14H,8-11,15H2,1-2H3,(H2,36,37,38);6-8H,1-3,5H2

1,2-Ethanedione, 1-(4-benzoyl-1-piperazinyl)-2-(4-methoxy-7-(3-methyl-1H-1,2,4-triazol-1-yl)-1-((phosphonooxy)methyl)-1H-pyrrolo(2,3-c)pyridin-3-yl)-, compd. with 2-amino-2-(hydroxymethyl)-1,3-propanediol (1:1)

Fostemsavir tromethamine; BMS663068; 864953-39-9; Fostemsavir tromethamine; Fostemsavir Tris; BMS-663068 Tris; BMS 663068 (Tris); BMS-663068 (Tris); Fostemsavir trometamol; Rukobia; BMS-663068; BMS 663068; BMS-663068-03; GSK3684934A

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

DMSO : ~125 mg/mL (~177.40 mM)
H2O : ~100 mg/mL (~141.92 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (2.95 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 20.8 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 2: ≥ 2.08 mg/mL (2.95 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 20.8 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 3: ≥ 2.08 mg/mL (2.95 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 50 mg/mL (70.96 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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