Diacylglycerol acyltransferase-1 (DGAT-1) - inhibitor [1]
- DGAT-1 enzyme IC50: 0.0005 μM (0.5 nM) [1]
- Cellular IC50 (inhibition of triacylglycerol (TAG) synthesis in human HuTu 80 cells): 0.0005 μM (0.5 nM) [1]
- No significant activity against DGAT-2, hERG potassium channel (IC50 > 30 μM), and cytochrome P450 enzymes CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 (all IC50 > 30 μM). [1]

AZD3988 (compound 53) has an IC50 value of 0 and can inhibit DGAT-1 at 10 μM. Human: 6 nM, 0. 0.5 nM (HuTu 80 cells), 1.1 nM (mouse), and 5 nM (rat) [1].

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AZD3988 demonstrated potent inhibition of DGAT-1 enzyme activity with an IC50 of 0.0005 μM. [1]
- In a cell-based assay measuring triacylglycerol synthesis in human HuTu 80 intestinal cells, AZD3988 showed excellent potency with an IC50 of 0.0005 μM, matching its enzyme potency. [1]
- The compound exhibited high selectivity, showing no significant inhibition of the closely related DGAT-2 enzyme. It also showed no significant activity against the hERG potassium channel and a panel of five major cytochrome P450 enzymes (CYP1A2, 2C9, 2C19, 2D6, 3A4), with IC50 values all greater than 30 μM. [1]
- The ligand lipophilicity efficiency (LLE) of AZD3988 was calculated to be 6.2, based on its pIC50 (9.3) and logD (3.1). This high LLE value was a key achievement of the optimization campaign. [1]

AZD3988 (compound 53) exhibits good in vivo pharmacokinetic effectiveness (iv, po; 0.5, 1, 2, 5 mg/kg) [1].

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In an oral lipid tolerance test (OLTT) in fasted rats, AZD3988 was administered orally 2 hours before a bolus dose of corn oil. It dose-dependently reduced the plasma triacylglycerol (TAG) excursion measured 1.5 hours after the oil challenge. Inhibition of 40%, 66%, and 73% was observed at doses of 0.03, 0.1, and 0.2 mg/kg, respectively. [1]
- A direct response PK/PD model (Emax sigmoidal) successfully fit the relationship between plasma TAG and free plasma concentration of AZD3988 in the rat OLTT. The estimated in vivo IC50 from this model was 0.00005 μM, which is 10-fold lower than the in vitro IC50, suggesting that local inhibition of DGAT-1 in the gut, rather than systemic exposure, is the primary driver of efficacy in this model. [1]
- In a rat adipose TAG synthesis assay, AZD3988 dose-dependently decreased the ratio of radiolabel incorporation into TAG vs. DAG (TAG:DAG ratio). Reductions of 33%, 65%, 78%, and 78% were observed at doses of 0.1, 0.3, 1, and 3 mg/kg, respectively. [1]
- A direct response PK/PD model for the adipose tissue assay yielded an in vivo IC50 of 0.0003 μM for AZD3988, which is in very good agreement with its in vitro IC50 (0.0005 μM). This indicates that free plasma concentration is a good surrogate for compound concentration at the target in this tissue. [1]
- In a diet-induced obesity (DIO) mouse model, AZD3988 was administered twice daily (at 6:00 and 16:00) for 3 days. This treatment resulted in a statistically significant and progressive reduction in body weight compared to both the starting weight and vehicle-treated DIO control mice. Free plasma concentrations of AZD3988 were maintained >20-fold above its in vitro IC50 throughout the dosing interval. [1]
- AZD3988 had no effect on body weight in lean animals, and effects on food intake were only observed in animals fed a high-fat diet, suggesting the body weight effects are specific to the DGAT-1 mechanism in an obese state. [1]

Triacylglycerol (TAG) Synthesis Assay in HuTu 80 Cells: Human HuTu 80 intestinal cells were used to measure the inhibition of TAG synthesis by AZD3988. The compound was incubated with the cells, and the incorporation of radiolabeled precursors into TAG was quantified. The IC50 was determined to be 0.0005 μM. [1]

Animal/Disease Models: Mice, rats and dogs [1]
Doses: 0.5, 1, 2, 5 mg/kg
Route of Administration: intravenous (iv) (iv)injection of 0.5 mg/kg (mouse), 2 mg/kg (rat) and 1 mg/kg (dog) and orally 1 mg/kg (mouse), 5 mg/kg (rat) and 1 mg/kg (dog)
Experimental Results: Species Clp (mL/min/kg) Vdss(L/kg) IV Half-life (h) po Half-life (h) po Cmax (lM) Bioavailability (%) Mice 4.6 0.99 4.9 4.7 1.9 >100 Rats 1.1 0.35 3.4 5.8 20 >100 Dogs 2.5 0.36 1.8 5.7 1.5 32

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Oral Lipid Tolerance Test (OLTT) in Rats:** Fasted rats were orally dosed with AZD3988 (0.03, 0.1, 0.2 mg/kg) or vehicle. Two hours later, they received a bolus dose of corn oil. Plasma TAG levels were measured 1.5 hours after the oil challenge to assess the compound's effect on postprandial TAG excursion. [1]
- **Adipose TAG Synthesis Assay in Rats:** Rats were dosed with AZD3988 (0.1, 0.3, 1, 3 mg/kg) or vehicle. At a specific time point (presumably after compound administration and a radiolabeled precursor), adipose tissue was collected. The ratio of radiolabel incorporated into TAG versus diacylglycerol (DAG) was measured as a marker of DGAT-1 activity in the tissue. [1]
- **Diet-Induced Obesity (DIO) Mouse Study:** DIO mice on a high-energy cafeteria diet were treated with AZD3988 or vehicle twice daily (at 6:00 and 16:00) for 3 days. Body weight was measured daily. Free plasma concentrations of the compound were monitored to ensure target coverage. [1]
- **Pharmacokinetic (PK) Studies:** AZD3988 was dosed intravenously (IV) and orally (PO) in mice, rats, and dogs to determine key PK parameters. Formulations included 5% DMSO:95% hydroxypropyl β-cyclodextrin for IV dosing and hydroxypropyl methylcellulose (HPMC) with 0.1% polysorbate for PO dosing. Blood samples were collected at various time points, and plasma concentrations were analyzed. [1]

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Oral Lipid Tolerance Test (OLTT) in Rats: Fasted rats were orally dosed with AZD3988 (0.03, 0.1, 0.2 mg/kg) or vehicle. Two hours later, they received a bolus dose of corn oil. Plasma TAG levels were measured 1.5 hours after the oil challenge to assess the compound's effect on postprandial TAG excursion. [1]
- Adipose TAG Synthesis Assay in Rats: Rats were dosed with AZD3988 (0.1, 0.3, 1, 3 mg/kg) or vehicle. At a specific time point (presumably after compound administration and a radiolabeled precursor), adipose tissue was collected. The ratio of radiolabel incorporated into TAG versus diacylglycerol (DAG) was measured as a marker of DGAT-1 activity in the tissue. [1]
- Diet-Induced Obesity (DIO) Mouse Study: DIO mice on a high-energy cafeteria diet were treated with AZD3988 or vehicle twice daily (at 6:00 and 16:00) for 3 days. Body weight was measured daily. Free plasma concentrations of the compound were monitored to ensure target coverage. [1]
- Pharmacokinetic (PK) Studies: AZD3988 was dosed intravenously (IV) and orally (PO) in mice, rats, and dogs to determine key PK parameters. Formulations included 5% DMSO:95% hydroxypropyl β-cyclodextrin for IV dosing and hydroxypropyl methylcellulose (HPMC) with 0.1% polysorbate for PO dosing. Blood samples were collected at various time points, and plasma concentrations were analyzed. [1]

Pharmacokinetic parameters for AZD3988 were determined in three preclinical species: [1]
- Mouse: Clearance (Clp) = 4.6 mL/min/kg; Volume of distribution (Vdss) = 0.99 L/kg; IV half-life = 4.9 h; PO half-life = 4.7 h; PO Cmax = 1.9 μM; Bioavailability > 100%. [1]
- Rat: Clearance (Clp) = 1.1 mL/min/kg; Volume of distribution (Vdss) = 0.35 L/kg; IV half-life = 3.4 h; PO half-life = 5.8 h; PO Cmax = 20 μM; Bioavailability > 100%. [1]
- Dog: Clearance (Clp) = 2.5 mL/min/kg; Volume of distribution (Vdss) = 0.36 L/kg; IV half-life = 1.8 h; PO half-life = 5.7 h; PO Cmax = 1.5 μM; Bioavailability = 32%. [1]
- The compound showed good cellular permeability, balancing its moderate aqueous solubility to achieve good oral exposure. [1]

[1]. Identification, optimisation and in vivo evaluation of oxadiazole DGAT-1 inhibitors for the treatment of obesity and diabetes. Bioorg Med Chem Lett. 2012 Jun 15;22(12):3873-8.

AZD3988 (compound 53) is a potent and selective inhibitor of diacylglycerol acyltransferase-1 (DGAT-1). It was discovered through an extensive optimization campaign starting from an oxadiazole amide high-throughput screening hit (compound 1). [1]
- The optimization strategy focused on improving both potency and ligand lipophilicity efficiency (LLE), ultimately achieved by incorporating a carboxylic acid group into the molecule. AZD3988 successfully met these key aims with high potency (IC50 = 0.0005 μM) and high LLE (6.2). [1]
- DGAT-1 is an enzyme that catalyzes the final step in triacylglycerol synthesis. Its inhibition is a therapeutic strategy for treating obesity, diabetes, and other components of metabolic syndrome. [1]
- AZD3988 demonstrated excellent in vivo efficacy in multiple rodent models, including an oral lipid tolerance test (OLTT), an adipose tissue TAG synthesis assay, and a diet-induced obesity (DIO) model. PK/PD modeling successfully correlated plasma drug concentrations with these pharmacological effects. [1]
- The compound showed favorable pharmacokinetic properties across three preclinical species (mouse, rat, dog) with high oral bioavailability in rodents. [1]

C23H22F2N4O4

456.44

456.161

892489-52-0

23648867

White to off-white solid powder

1.402

1.627

5.238

3

9

7

33

671

0

NGEBYTLALFOQKI-UHFFFAOYSA-N

InChI=1S/C23H22F2N4O4/c24-18-10-9-17(12-19(18)25)27-23-29-28-22(33-23)21(32)26-16-7-5-15(6-8-16)14-3-1-13(2-4-14)11-20(30)31/h5-10,12-14H,1-4,11H2,(H,26,32)(H,27,29)(H,30,31)

2-[4-[4-[[5-(3,4-difluoroanilino)-1,3,4-oxadiazole-2-carbonyl]amino]phenyl]cyclohexyl]acetic acid

AZD3988 AZD 3988 AZD-3988

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)

DMSO : ~16.67 mg/mL (~36.52 mM)

Solubility in Formulation 1: ≥ 1.67 mg/mL (3.66 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 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.

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Solubility in Formulation 2: ≥ 1.67 mg/mL (3.66 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.

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