Etrumadenant (AB928; AB-928) is a first-in-class, clinical stage, oral and dual antagonist of the A2aR and A2bR adenosine receptors with potential anticancer and immunomodulatory activity. In conjunction with chemotherapy, it can inhibit adenosine-mediated immunosuppression, resulting in increased immune activation and decreased tumor growth.

Physicochemical Properties

Molecular Formula	C23H22N8O
Molecular Weight	426.473783016205
Exact Mass	426.19
Elemental Analysis	C, 64.77; H, 5.20; N, 26.27; O, 3.75
CAS #	2239273-34-6
Related CAS #	2239273-34-6
PubChem CID	135242184
Appearance	Off-white to light yellow solid powder
LogP	1.4
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	5
Heavy Atom Count	32
Complexity	680
Defined Atom Stereocenter Count	0
InChi Key	BUXIAWLTBSXYSW-UHFFFAOYSA-N
InChi Code	InChI=1S/C23H22N8O/c1-14-15(11-24)6-4-8-17(14)18-10-19(28-22(25)27-18)20-13-31(30-29-20)12-16-7-5-9-21(26-16)23(2,3)32/h4-10,13,32H,12H2,1-3H3,(H2,25,27,28)
Chemical Name	3-[2-amino-6-[1-[[6-(2-hydroxypropan-2-yl)pyridin-2-yl]methyl]triazol-4-yl]pyrimidin-4-yl]-2-methylbenzonitrile
Synonyms	AB-928; Etrumadenant; AB928; AB928; 2239273-34-6; Etrumadenant; AB-928; 3-(2-Amino-6-(1-((6-(2-hydroxypropan-2-yl)pyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)pyrimidin-4-yl)-2-methylbenzonitrile; 3-[2-Amino-6-[1-[[6-(2-hydroxypropan-2-yl)pyridin-2-yl]methyl]triazol-4-yl]pyrimidin-4-yl]-2-methylbenzonitrile; Etrumadenant [USAN]; W0ZE0NT8IF;AB 928
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

Targets	A2AR ( Kd = 1.4 nM ); A2bR ( Kd = 2 nM )
ln Vitro	MoDC that underwent adenosine differentiation in human in vitro cell cultures demonstrated a reduced capacity to induce IFN-γ secretion from allogenic CD4+ T-cells in a MLR. Etrumadenant is added, and this suppression is greatly reversed. A cassette of 39 genes that are controlled by adenosine during moDC differentiation was discovered by multiplexed gene expression profiling with NanoString. These changes in gene expression are rescued by etrumadenant[2].
ln Vivo	Etrumadenant plus chemotherapy leads to a markedly decreased tumor volume in vivo when AT3-OVA tumors are used for treatment; Etrumadenant plus NSC 266046 produces similar outcomes. Moreover, AB928 can inhibit the growth of B16-F10 tumors when used alone or in conjunction with α-PD-1 therapy. In mouse syngeneic tumors, etrumadenant stimulates the antitumor immune response, which inhibits tumor growth and increases immune cell infiltration[2].
Cell Assay	PBMC is used to isolate CD4+ or CD8+ T cells using RosetteSep separation. Adenosine/EHNA +/- AB928 +/- CD2/CD3/CD28 microbeads are then used to stimulate the cells. After six days in IL-4/GM-CSF +/- adenosine/EHNA, +/- AB928; human CD14+ cells are differentiated into moDC. When moDCs are activated by LPS or IFN-y, adenosine is present. Before initiating the mixed leukocyte reaction (MLR), cells are rinsed in excess buffer to get rid of any remaining adenosine. Four days after the moDC/CD4 co-culture is started, supernatants are extracted.
Animal Protocol	female C57BL/6 mice 100 mg/kg Oral gavage Mouse syngeneic tumor studies were conducted using C57BL/6 mice inoculated with mouse mammary tumor AT3-OVA or melanoma B16-F10 cells. Tumors were subsequently treated with doxorubicin, oxaliplatin, or α-PD-1 +/- AB928.[2]
References	[1]. Safety, tolerability, and pharmacology of AB928, a novel dual adenosine receptor antagonist, in a randomized, phase 1 study in healthy volunteers. Invest New Drugs. 2019 Aug;37(4):711-721. [2]. AB928, a dual antagonist of the A2aR and A2bR adenosine receptors, relieves adenosine-mediated immune suppression
Additional Infomation	Etrumadenant is an orally bioavailable antagonist of both the immunomodulatory checkpoint molecules adenosine A2A receptor (A2AR; ADORA2A) and A2B receptor (A2BR; ADORA2B), with potential immunomodulating and antineoplastic activities. Upon administration, etrumadenant competes with tumor-released adenosine for binding to A2AR and A2BR expressed on numerous intra-tumoral immune cells, such as dendritic cells (DCs), natural killer (NK) cells, macrophages and T-lymphocytes. The binding of AB928 to A2AR and A2BR inhibits A2AR/A2BR activity and prevents adenosine-A2AR/A2BR-mediated signaling. A2AR/A2BR inhibition activates and enhances the proliferation of various immune cells, abrogates the adenosine-mediated immunosuppression in the tumor microenvironment (TME) and activates the immune system to exert anti-tumor immune responses against cancer cells, which leads to tumor cell killing. A2AR and A2BR, G protein-coupled signaling receptors, are expressed on the cell surfaces of numerous immune cells. Adenosine is often overproduced by tumor cells and plays a key role in immunosuppression and tumor cell proliferation.

Solubility Data

Solubility (In Vitro)

DMSO: 85~250 mg/mL (199.3~586.2 mM) Ethanol: ~5 mg/mL

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.88 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. Solubility in Formulation 2: ≥ 2.08 mg/mL (4.88 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. Solubility in Formulation 3: ≥ 2.08 mg/mL (4.88 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. Solubility in Formulation 4: 5% DMSO + 95% Corn oil: 0.7mg/ml (1.64mM)  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.3448 mL	11.7242 mL	23.4483 mL
	5 mM	0.4690 mL	2.3448 mL	4.6897 mL
	10 mM	0.2345 mL	1.1724 mL	2.3448 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.