The primary target of Galidesivir is the viral RNA-dependent RNA polymerase (RdRp). As an adenosine nucleoside analog, Galidesivir is phosphorylated intracellularly to its active triphosphate form, which mimics ATP and is incorporated into the growing viral RNA chain by RdRp. This leads to non-obligate RNA chain termination, preventing further viral RNA synthesis and thereby inhibiting viral replication. Galidesivir's broad-spectrum activity is due to the conserved nature of the RdRp active site across many RNA virus families. The compound's selectivity for viral RdRp over host polymerases contributes to its favorable safety profile.

Gadesivir (BCX4430) is phosphorylated by cellular kinases to a triphosphate that resembles ATP; viral RNA polymerase incorporates the drug's monophosphate nucleotide into the RNA chain, resulting in an early termination of the chain [1]. Vero cell YFV infection is effectively inhibited by galidesivir. The neutral red absorption experiment yielded an EC50 of 8.3 μg/ml (24.5 μM) [3].

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In vitro, Galidesivir exhibits broad-spectrum antiviral activity against a wide range of RNA viruses. It is active against filoviruses such as Ebola and Marburg viruses, as well as emerging infectious agents including MERS-CoV, SARS-CoV, and SARS-CoV-2. The compound inhibits viral replication in cell culture with EC50 values in the low micromolar range. Its antiviral activity is mediated by inhibition of RdRp, leading to disruption of viral RNA synthesis. Galidesivir has been shown to be effective against multiple strains of these viruses, supporting its potential as a broad-spectrum antiviral agent.

Galidesivir (BCX4430) is active in a range of experimental infections following intramuscular, intraperitoneal, and oral injection. Galidesivir has showed high efficacy in nonclinical studies involving fatal infections with Ebola, Marburg, Rift Valley disease, and yellow fever viruses [1]. Gardesivir (4 mg/kg; intraperitoneally; twice daily for 7 days) is efficacious in a hamster model of yellow fever (YF) [4].

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In vivo, Galidesivir has demonstrated efficacy in animal models of viral infection. It reduces lung infections in infected animals. In studies on Rift Valley fever virus (RVFV), Galidesivir dosed at 400/100 mg/kg/day provided protection with 70% of animals surviving a uniformly lethal challenge. The compound has been shown to be active in animal models of Ebola, Marburg, yellow fever, Zika, and Rift Valley fever. These in vivo efficacy data support its potential as a therapeutic agent for emerging viral infections. Galidesivir has also been evaluated in clinical trials for yellow fever and COVID-19.

The in vitro antiviral activity of Galidesivir can be assessed using cell-free RdRp enzyme assays. A typical protocol involves incubating recombinant viral RdRp with a template-primer RNA, NTPs (including radiolabeled or fluorescently labeled ATP), and Galidesivir at various concentrations. The incorporation of Galidesivir triphosphate into the growing RNA chain is assessed by measuring the amount of RNA synthesized or by analyzing the chain termination products. The IC50 value is determined by plotting the percentage of RdRp activity remaining against the compound concentration. The selectivity of the compound for viral RdRp over host polymerases can be assessed using similar assays with mammalian polymerases.

For in vitro cellular experiments, virus-permissive cell lines (e.g., Vero cells, Huh-7 cells) are cultured in appropriate media and infected with the virus of interest. Cells are treated with Galidesivir at various concentrations (typically 0.1-100 microM) either before, during, or after infection. Viral replication is assessed by measuring viral RNA levels using qRT-PCR, viral titers using plaque assays or TCID50, or viral protein expression using immunostaining. The EC50 (half-maximal effective concentration) is determined by plotting the percentage of viral inhibition against the compound concentration. Cytotoxicity is assessed in parallel to determine the selectivity index (CC50/EC50).

Animal/Disease Models: Female Syrian golden hamster (hamster infected with YF virus) [4]
Doses: 4 mg/kg body weight
Route of Administration: intraperitoneal (ip) injection; twice a day for 7 days
Experimental Results: Dramatically improved the survival of YFV-infected hamsters Rate.

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In vivo animal experiments with Galidesivir typically involve administration via intramuscular (IM) or intravenous (IV) injection in animal models of viral infection. A common dosing regimen is 5-15 mg/kg, administered once or twice daily. For efficacy studies, animals are infected with a lethal dose of the virus, and Galidesivir is administered either prophylactically or therapeutically. Survival is monitored for 14-28 days, and viral load in blood and tissues is measured at various time points by qRT-PCR or plaque assays. The compound's effect on disease progression and pathology is assessed by histopathological analysis. Pharmacokinetic and toxicity studies are also performed in uninfected animals.

Galidesivir has been evaluated in pharmacokinetic studies in healthy human subjects. It is administered via intramuscular (IM) and intravenous (IV) formulations. Following administration, Galidesivir is converted intracellularly to its active triphosphate anabolite, which is the active antiviral species. The compound is stable in S9 fractions across species and in multiple cell lines and hepatocytes. Its pharmacokinetic profile is characterized by dose-dependent exposure and a moderate half-life. Galidesivir has been shown to be safe and well-tolerated in healthy subjects in phase 1 clinical trials.

Galidesivir has been evaluated in clinical trials for safety and tolerability in healthy subjects. It has been shown to be safe and well-tolerated at therapeutic doses. In animal studies, no significant toxicity has been reported at doses that achieve efficacious plasma concentrations. The compound's selectivity for viral RdRp over host polymerases contributes to its favorable safety profile. However, as with any antiviral agent, potential toxicities may include effects on host nucleotide metabolism. Long-term safety studies are needed to fully characterize its toxicity profile. The compound is for research use and has been investigated in clinical trials.

[1]. BCX4430 - A broad-spectrum antiviral adenosine nucleoside analog under development for the treatment of Ebola virus disease. J Infect Public Health. 2016;9(3):220-226.

[2]. ICN-1229, Remdesivir, PSI-7977, Galidesivir, and GS 1278 against SARS-CoV-2 RNA dependent RNA polymerase (RdRp): A molecular docking study. Life Sci. 2020 Mar 25:117592.

[3]. Protection against filovirus diseases by a novel broad-spectrum nucleoside analogue BCX4430. Nature. 2014;508(7496):402-405.

[4]. BCX4430, a novel nucleoside analog, effectively treats yellow fever in a Hamster model. Antimicrob Agents Chemother. 2014;58(11):6607-6614.

Galidisevir is an adenosine analogue currently being investigated for its use against the Zaire Ebola virus. Animal studies have shown that galidisevir effectively improves the survival rate of animals infected with a variety of pathogens, including Ebola virus, Marburg virus, yellow fever virus, and Zika virus. In vitro experiments have demonstrated that galidisevir has broad-spectrum antiviral activity against a variety of positive and negative-sense RNA viruses, including coronaviruses, filoviruses, and arenaviruses. A Phase I clinical trial has been initiated to determine the safety of the drug in humans. Because it is also effective against other coronaviruses, it may be investigated as a potential treatment for COVID-19. Galidisevir is an adenosine analogue and RNA polymerase inhibitor with potential broad-spectrum antiviral activity. After administration, galidisevir is metabolized to a monophosphate form, which is then converted to an active triphosphate. Galidisevir triphosphate binds to viral RNA-dependent RNA polymerase (RdRp) and is incorporated into the elongating viral RNA chain, causing premature chain termination. This can prevent viral transcription and replication. Mechanism of Action Galidisevir exerts its effect by binding to the native nucleotide binding site of viral RNA polymerase. This alteration in electrostatic interactions leads to a structural change in the viral enzyme. Disruption of viral RNA polymerase activity results in premature termination of the elongating RNA chain. Pharmacodynamics Galidisevir is an adenosine analogue with broad-spectrum antiviral activity against a variety of RNA viruses, including flaviviruses, capsid viruses, Bunyaviruses, arenaviruses, paramyxoviruses, coronaviruses, filamentous viruses, orthomyxoviruses, and microviruses.

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Galidesivir (BCX4430) is a broad-spectrum antiviral compound and an adenosine nucleoside analog. It acts as a direct-acting antiviral agent that disrupts viral RNA-dependent RNA polymerase (RdRp) activity. Galidesivir is active in vitro against many RNA viral pathogens, including filoviruses and emerging infectious agents such as MERS-CoV, SARS-CoV, and SARS-CoV-2. It was originally developed for Hepatitis C but has been advanced as a potential treatment for filovirus infections. Galidesivir reduces lung infections in infected animals and has been evaluated in clinical trials for yellow fever and COVID-19. It is an investigational compound not yet approved for clinical use.

C₁₁H₁₅N₅O₃

265.27

265.117

249503-25-1

Galidesivir hydrochloride;222631-44-9

10445549

White to off-white solid powder

1.6±0.1 g/cm3

661.2±55.0 °C at 760 mmHg

353.7±31.5 °C

0.0±2.1 mmHg at 25°C

1.782

-3.03

6

7

2

19

334

4

C1=C(C2=C(N1)C(=NC=N2)N)[C@H]3[C@@H]([C@@H]([C@H](N3)CO)O)O

AMFDITJFBUXZQN-KUBHLMPHSA-N

InChI=1S/C11H15N5O3/c12-11-8-6(14-3-15-11)4(1-13-8)7-10(19)9(18)5(2-17)16-7/h1,3,5,7,9-10,13,16-19H,2H2,(H2,12,14,15)/t5-,7+,9-,10+/m1/s1

(2S,3S,4R,5R)-2-(4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)-5-(hydroxymethyl)pyrrolidine-3,4-diol

BCX4430 BCX 4430 BCX-4430 Immucillin A

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)

H2O : ~100 mg/mL (~376.97 mM)

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.)