Vesatolimod (formerly known as GS9620; GS-9620) is a novel potent, selective and orally bioactive small molecule agonist of Toll-like receptor 7 (TLR-7) with antiviral activity. It activates TLR-7 with an EC50 of 291 nM. Vesatolimod has the potential for the treatment of chronic hepatitis B viral (HBV) infection. GS-9620 selectively induces IFN-α, cytokines and chemokines. The minimum effective concentrations for IFN-α induction were similar in pDCs and in PBMCs from HCV-positive donors. GS-9620 demonstrates an EC50 of 291 nM for human TLR7, which is 30-fold selectivity over TLR8 with EC50 of 9 μM.

Physicochemical Properties

Molecular Formula	C22H30N6O2
Molecular Weight	410.52
Exact Mass	410.243
CAS #	1228585-88-3
Related CAS #	1228585-88-3;1454806-18-8 (HCl);
PubChem CID	46241268
Appearance	White to yellow solid powder
Density	1.2±0.1 g/cm3
Index of Refraction	1.622
LogP	3.1
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	8
Heavy Atom Count	30
Complexity	558
Defined Atom Stereocenter Count	0
InChi Key	VFOKSTCIRGDTBR-UHFFFAOYSA-N
InChi Code	InChI=1S/C22H30N6O2/c1-2-3-11-30-22-25-20(23)19-21(26-22)28(15-18(29)24-19)14-17-8-6-7-16(12-17)13-27-9-4-5-10-27/h6-8,12H,2-5,9-11,13-15H2,1H3,(H,24,29)(H2,23,25,26)
Chemical Name	4-amino-2-butoxy-8-[[3-(pyrrolidin-1-ylmethyl)phenyl]methyl]-5,7-dihydropteridin-6-one
Synonyms	GS9620; GS 9620; GS-9620
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Vesatolimod (GS-9620) enters cells quickly, localizes to endo-lysosomal compartments preferentially, and communicates from these areas. The kinetics of the compound's cellular absorption in Daudi cells using tritiated Vesatolimod (3H-GS-9620) is studied in order to test this notion. The buildup of 3H-GS-9620 proceeds quickly; it takes about thirty minutes to attain a concentration-dependent steady-state equilibrium. The concentration of 3H-Vesatolimod measured within cells is five times more than the concentration of 3H-GS-9620 used outside cells for treatment. Elevations in 3H-GS-9620 concentrations are approximately correlated with increases in intracellular 3H-Vesatolimod concentrations[1].
ln Vivo	In uninfected chimpanzees, single oral doses of Vesatolimod (GS-9620) at 0.3 and 1 mg/kg show a dose- and exposure-related elevation of serum IFN-α, some cytokines/chemokines, and IFN-stimulated genes (ISG) in the liver and peripheral circulation. The Cmax values of Vesatolimod (GS-9620) after oral administration at 0.3 (n=3) and 1 mg/kg (n=3 and n=4) are 3.6±3.5, 36.8±34.5, and 55.4± 81.0 nM, respectively. After 8 hours, serum IFN responses reach their peak. At dosages of 0.3 and 1 mg/kg, the mean peak values of induced serum IFN-α are 479 and 66 pg/mL, respectively. Treatment with vesatolimod (GS-9620) produces ISG transcripts in peripheral blood mononuclear cells (PBMC) at 0.3 mg/kg and in the liver at 1 mg/kg. These transcripts include ISG15, OAS-1, MX1, IP-10 (CXCL10), and I-TAC (CXCL11)[2].
Animal Protocol	1 and 2 mg/kg; oral Chimpanzees
References	[1]. Molecular Determinants of GS-9620-Dependent TLR7 Activation. PLoS One. 2016 Jan 19;11(1):e0146835. [2]. GS-9620, an Oral Agonist of Toll-Like Receptor-7, Induces Prolonged Suppression of Hepatitis B Virus in Chronically Infected Chimpanzees. Gastroenterology. 2013 Feb 13. pii: S0016-5085(13)00169-8. [3]. Preclinical Characterization of GS-9620, A Potent and Selective Oral TLR7 Agonist.
Additional Infomation	Vesatolimod is aninvestigational drugthat is being studied to treat HIV infection. Vesatolimod belongs to a group of HIV drugs called immune modulators. Immune modulators (also called immunomodulators) are substances that help to activate, boost, or restore normal immune function. Vesatolimod’s potential role as a latency-reversing agent has also been evaluated in preclinical and clinical trials; however, results thus far have been mixed. Vesatolimod has been used in trials studying the treatment of Hepatitis B and Chronic Hepatitis B.

Solubility Data

Solubility (In Vitro)

DMSO: >4 mg/mL Water:<1 mg/mL Ethanol:<1 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 1.67 mg/mL (4.07 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 16.7 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. Solubility in Formulation 2: 1.67 mg/mL (4.07 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 16.7 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. Solubility in Formulation 3: ≥ 1.67 mg/mL (4.07 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 16.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.4359 mL	12.1797 mL	24.3593 mL
	5 mM	0.4872 mL	2.4359 mL	4.8719 mL
	10 mM	0.2436 mL	1.2180 mL	2.4359 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.