HCV NS5B

VX-222 attaches itself to the HCV RNA-dependent RNA polymerase's thumb II allosteric pocket. With an IC50 of 0.94 and 1.2 μM, respectively, VX-222 shows non-competitive and selective inhibition in HCV NS5B of genotypes 1a and 1b. Subgenomic HCV genotypes 1a and 1b are specifically inhibited by VX-222, with EC50 values of 22.3 and 11.2 nM, respectively. (Source: ) Similarly, VX-222 inhibits the 1b/Con1 HCV subgenomic replicon with an EC50 of 5 nM, according to a recent study. While having little to no effect on de novo-initiated RNA synthesis, VX-222 preferentially inhibits primer-dependent RNA synthesis.

VCH-222 exhibits fine pharmacokinetic properties in rats and dogs, such as low total body clearance, excellent oral bioavailability (more than 30%), and good ADME characteristics. Multiple enzymes (CYP1A1, 2A6, 2B6, 2C8, CYP 3A4, UGT1A3) biotransform VCH-222. It is expected that VCH-222 is actively transported in the liver and excreted mostly intact in bile or as glucuronide adducts.

VX-222's inhibitory effect on HCV NS5B activity is quantified by measuring the amount of radiolabeled UTP incorporated by the enzyme's C-terminal ∆21 truncated version in a freshly synthesized RNA using a homopolymeric RNA template / primer called poly rA / oligo dT. Liquid scintillation counters are used to quantitatively detect incorporated radioactivity. In vitro kinetics of VX-222-induced inhibition of HCV NS5B from genotype 1b strain BK are ascertained by employing the C-terminal ∆21 truncated form of NS5B. When VX-222 (1 to 1.5 μM) is combined with 0.89 to 6.70 μCi of [α-33P]-labeled UTP and 10 to 75 μM nonradioactive UTP, testing is conducted. 18 minutes at 22 °C are given to RNA-dependent RNA polymerase reactions.

Trypsinized Huh7.5 cells containing HCV RNA replicons are plated at a density of 4 × 104 cells per well into 48-well plates. The following day, 200 μL of the full medium is added to the new medium along with VX-222. Following a 48-hour period, total RNA is extracted, and real-time reverse transcription-PCR (RT-PCR) is used to quantify viral RNAs. With the use of nonlinear regression analysis and log curve fitting, the effective drug concentrations (EC50) that decreased HCV RNA replicon levels by 50% are determined.

Rat IV formulations were prepared as solutions in 10% DMI/15% EtOH/35% PPG/40% dextrose/5% in water. IV formulations for dogs and monkeys were prepared as solutions in saline. PO formulations for rats were prepared as suspensions in 0.5% MC/0.1% SLS/99.4% water. For the PO studies, male Sprague-Dawley rats were instrumented with either a carotid artery cannula to facilitate blood collection and/or a single bile duct cannula to facilitate bile collection. For IV studies, male Sprague-Dawley rats were additionally fitted with a jugular vein catheter for dose administration. Blood samples were collected at intervals to 72 hours post dose. EDTA was used as anticoagulant and plasma was prepared by centrifugation. Bile duct cannulated rats received a 15mg/kg PO dose; bile, urine, and feces were collected at intervals to 72 hours. In the tissue distribution study, male Sprague-Dawley rats received a 10 mg/kg PO dose and specified tissues were collected following euthanasia at 1, 2, 4, 7 and 24 hours post dose.ACS Med Chem Lett. 2017;8(2):251-255.

[1]. Biochemical study of the comparative inhibition of hepatitis C virus RNA polymerase by VX-222 and filibuvir.Antimicrob Agents Chemother. 2012 Feb;56(2):830-7.

[2]. Inhibitors of hepatitis C virus--current standards and status of investigations].Przegl Epidemiol. 2010;64(4):473-8. .

5-(3,3-Dimethylbut-1-ynyl)-3-[(4-hydroxycyclohexyl)-[(4-methylcyclohexyl)-oxymethyl]amino]-2-thiophenic acid is a thiophenic carboxylic acid. Lomibvir has been used in clinical trials for the treatment of chronic hepatitis C virus (HCV) and chronic HCV infection. Filibuvir and VX-222 are non-nucleoside inhibitors (NNIs) that bind to the thumb II allosteric pocket of HCV RNA-dependent RNA polymerase. Both compounds have shown significant efficacy in clinical trials, therefore, a deeper understanding of their inhibitory mechanisms is crucial. In this study, fenibvir and VX-222 inhibited the HCV 1b/Con1 subgenomic replicon at half-maximal effective concentrations (EC50) of 70 nM and 5 nM, respectively. Biochemical analysis using various RNA templates revealed that both compounds preferentially inhibited primer-dependent RNA synthesis, with little or no effect on de novo RNA synthesis. The dissociation constants of fenibvir and VX-222 with HCV polymerase are 29 nM and 17 nM, respectively. We analyzed the effects of three potential resistance mutations in the thumb II pocket on the inhibitory effects of these two compounds. In subgenomic replicon and enzyme activity analysis, the M423T mutation in RNA polymerase increased resistance to fenibvir by at least 100-fold. This resistance was due to a 250-fold decrease in the binding affinity (K_d) of the mutant enzyme to fenibvir. In contrast, the inhibitory activity of VX-222 was only slightly affected by the M423T mutation, but was more significantly affected by the I482L mutation. [1] The current standard treatment for chronic hepatitis C is the combination of pegylated interferon α-2a (PegIFN-α) and ribavirin (RBV). A newer interferon IFN-α-2b has also been developed, but its efficacy has not improved. Overall, the efficacy of the above treatment regimens is not ideal. Therefore, researchers are continuously exploring new drugs for the treatment of hepatitis C. These studies aim to find novel agents that can inhibit the HCV replication cycle. For example, a novel analogue of ribavirin has been introduced, offering fewer side effects while maintaining the same efficacy. The activity of new drugs depends on the inhibition of the most important enzymes in the HCV replication cycle: RNA polymerase, protease, and helicase. NS5 polymerase inhibitors are classified into nucleoside (R-7128) and non-nucleoside (ANA-598, GS 9190, VCH-759, VX-222). In-depth studies of R-7128 analogues are currently underway. The effects of specific compounds in Phase I and II studies have been summarized. A promising prodrug is the non-nucleoside polymerase inhibitor ANA-598, which achieved a sustained virological response rate (SVR) of 75% in patients. Recently reported drug combinations form the basis of specific targeted antiviral therapy (STAT-C) against hepatitis C virus (HCV). These therapies can improve treatment efficacy, shorten the course of treatment, and reduce and limit side effects. [2]

C25H35NO4S

445.6147

445.228

C, 67.38; H, 7.92; N, 3.14; O, 14.36; S, 7.19

1026785-59-0

Lomibuvir;1026785-55-6

24798764

Typically exists as solid at room temperature

1.2±0.1 g/cm3

640.5±55.0 °C at 760 mmHg

341.2±31.5 °C

0.0±2.0 mmHg at 25°C

1.589

5.15

2

5

6

31

717

0

O=C(C1=C(N([C@@H]2CC[C@H](O)CC2)C([C@H]3CC[C@H](C)CC3)=O)C=C(C#CC(C)(C)C)S1)O

WPMJNLCLKAKMLA-UHFFFAOYSA-N

InChI=1S/C25H35NO4S/c1-16-5-7-17(8-6-16)23(28)26(18-9-11-19(27)12-10-18)21-15-20(13-14-25(2,3)4)31-22(21)24(29)30/h15-19,27H,5-12H2,1-4H3,(H,29,30)

5-(3,3-dimethylbut-1-ynyl)-3-[(4-hydroxycyclohexyl)-(4-methylcyclohexanecarbonyl)amino]thiophene-2-carboxylic acid

Lomibuvir; VX-222; 1026785-59-0; 1026785-55-6; VCH-222; VX-222 (VCH-222, Lomibuvir); cis-Lomibuvir; Lomibuvir (VX-222);

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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