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
The absorption of temsavir is significantly limited by suboptimal dissolution and solubility following oral administration. Fostemsavir, a phosphonooxymethyl prodrug of temsavir, has improved aqueous solubility and stability under acidic conditions as compared to its parent drug - following oral administration of fostemsavir, the absolute bioavailability is approximately 26.9%. The Cmax and AUCtau following oral administration of fostemsavir 600mg twice daily was 1770 ng/mL and 12,900 ng.h/L, respectively, with a Tmax of approximately 2 hours. Co-administration of fostemsavir with a standard meal increases its AUC by approximately 10%, while co-administration with a high-fat meal increases its AUC by approximately 81%.

Route of Elimination
Temsavir is highly metabolized, after which it is excreted in the urine and feces as inactive metabolites. Approximately 51% of a given dose is excreted in the urine, with <2% comprising unchanged parent drug, and 33% is excreted in the feces, of which 1.1% is unchanged parent drug.

Volume of Distribution
The steady-state volume of distribution of temsavir following intravenous administration is approximately 29.5 L.

Clearance
The mean clearance and apparent clearance of temsavir, the active metabolite of fostemsavir, are 17.9 L/h and 66.4 L/h, respectively.

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Metabolism / Metabolites
Fostemsavir is rapidly hydrolyzed to temsavir, its active metabolite, by alkaline phosphatase(s) present at the brush border membrane of the intestinal lumen. Temsavir undergoes further biotransformation to two predominant inactive metabolites: BMS-646915, a product of hydrolysis by esterases, and BMS-930644, an N-dealkylated metabolite generated via oxidation by CYP3A4. Approximately 36.1% of an administered oral dose is metabolized by esterases, 21.2% is metabolized by CYP3A4, and <1% is conjugated by UDP-glucuronosyltransferases (UGT) prior to elimination. Both temsavir and its two predominant metabolites are known to inhibit BCRP.

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Biological Half-Life
The half-life of temsavir is approximately 11 hours. Fostemsavir is generally undetectable in plasma following oral administration.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of fostemsavir during breastfeeding. Because the drug and its active metabolite temsavir are over 80% protein bound, the amounts in milk are likely to be low. Achieving and maintaining viral suppression with antiretroviral therapy decreases breastfeeding transmission risk to less than 1%, but not zero. Individuals with HIV who are on antiretroviral therapy with a sustained undetectable viral load and who choose to breastfeed should be supported in this decision. If a viral load is not suppressed, banked pasteurized donor milk or formula is recommended.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not 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 medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in treatment-experienced adults who meet certain requirements, as determined by a health care provider. Fostemsavir is always used in combination with other HIV medicines.
Fostemsavir Tromethamine is the tromethamine salt form of fostemsavir, an orally bioavailable phosphonooxymethyl prodrug of the human immunodeficiency virus type 1 (HIV-1) attachment inhibitor temsavir, with activity against HIV. Upon oral administration, fostemsavir is hydrolyzed to the active moiety temsavir. Temsavir targets and binds to the gp120 subunit within the HIV-1 envelope glycoprotein gp160. This selectively inhibits the interaction between HIV-1 virus and host cellular CD4 receptors, thereby preventing HIV-1 virus attachment. This also inhibits gp120-dependent post-attachment steps that are needed for HIV-1 viral entry into host cells.

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Drug Indication
Rukobia, in combination with other antiretrovirals, is indicated for the treatment of adults with multidrug resistant HIV-1 infection for whom it is otherwise not possible to construct a suppressive anti-viral regimen.

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.)