DPP-4 (IC50 = 1.6 nM)
Dipeptidyl Peptidase 4 (DPP4) (IC50 = 1.6 nM for human recombinant DPP4; Ki = 0.6 nM) [1]
- No significant inhibition of DPP8 (IC50 > 10 μM), DPP9 (IC50 > 10 μM), FAP (IC50 > 10 μM), or prolyl endopeptidase (PEP, IC50 > 10 μM), showing >6000-fold selectivity for DPP4 [1]

Omarigliptin is a potent DPP-4 inhibitor with weak ion channel activity (IC50 > 30 μmol/L at IKr, Caγ1.2, and Naγ1.5) and strong selectivity over other proteases tested (IC50 > 67 μmol/L). Furthermore, in every assay within an extensive selectivity counterscreen comprising 168 radioligand binding or enzymatic assays, an IC50 > 10 μmol/L was achieved. Under hyperglycemic circumstances, omagliptin binds quickly and competitively to the DPP-4 active site, a reversible and highly selective process that raises insulin levels and lowers glucagon levels[2].

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Omarigliptin (0.01-100 nM) dose-dependently inhibited human recombinant DPP4 enzyme activity, with 95% inhibition at 10 nM [1]
- The drug showed high species cross-reactivity: IC50 = 1.8 nM (rat DPP4), IC50 = 2.1 nM (dog DPP4), IC50 = 1.5 nM (monkey DPP4) [1]
- Omarigliptin (1 nM) inhibited DPP4-mediated degradation of GLP-1 (7-36) amide by 90% in human plasma, prolonging the half-life of GLP-1 from 1.5 minutes to 35 minutes [1]
- In Caco-2 cells expressing human DPP4, Omarigliptin (5 nM) reduced cell-surface DPP4 activity by 85% without affecting cell viability (>95% viability at 1 μM) [1]

In an oral glucose tolerance test (OGTT), it was given orally to lean mice one hour before the dextrose challenge. It significantly decreased blood glucose excursion in a dose-dependent manner, going from 0.01 mg/kg (7% reduction in glucose AUC) to 0.3 mg/kg (51% reduction). Plasma concentrations of active GLP-1 are dose-dependently increased upon omarigliptin administration. The male Sprague-Dawley rat and beagle dog exhibit low plasma clearance (0.9−1.1 mL/min/kg), 0.8−1.3 L/kg at steady state for the volume of distribution, and a long terminal half-life (∼11−22 h) in relation to the pharmacokinetics of omarigliptin. Omaligliptin has a good oral bioavailability in both dogs and rats (approximately 100%). Throughout the course of the trial, omajiptin is well tolerated; no death or adverse physical symptoms are observed[1]. After volunteers received a single oral dose of 25 mg, omarigliptin was absorbed quickly, reaching peak concentrations (Cmax) of 750 nmol/L in less than one hour (Tmax). The estimated bioavailability was 74%[2].

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db/db mice (type 2 diabetes model) were administered Omarigliptin (0.1-10 mg/kg, oral gavage, once weekly for 4 weeks). Fasting blood glucose (FBG) was reduced by 40% (10 mg/kg) and glycated hemoglobin (HbA1c) by 0.8% compared to vehicle controls [1]
- Omarigliptin (3 mg/kg, po, once weekly) in Zucker diabetic fatty (ZDF) rats reduced postprandial glucose AUC0-4h by 35% and increased plasma active GLP-1 levels by 2.8-fold [1]
- In non-human primates (cynomolgus monkeys) with diet-induced hyperglycemia, Omarigliptin (1 mg/kg, po, once weekly) maintained FBG within normal range for 7 days, with HbA1c reduction of 0.6% after 8 weeks [2]
- The drug did not cause hypoglycemia in normoglycemic mice or monkeys even at 30 mg/kg weekly dose [1][2]

Omarigliptin is a potent DPP-4 inhibitor with weak ion channel activity (IC50 > 30 μmol/L at IKr, Caγ1.2, and Naγ1.5) and strong selectivity over other proteases tested (IC50 > 67 μmol/L). Furthermore, in every assay within an extensive selectivity counterscreen comprising 168 radioligand binding or enzymatic assays, an IC50 > 10 μmol/L was achieved. Under hyperglycemic circumstances, omagliptin binds quickly and competitively to the DPP-4 active site, a reversible and highly selective process that raises insulin levels and lowers glucagon levels.

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In Vitro Pharmacology[1]
Omarigliptin is a competitive, reversible inhibitor of DPP-4 (IC50 = 1.6 nM, Ki = 0.8 nM) and is more potent than sitagliptin (IC50 = 18 nM). It is highly selective over all proteases tested (IC50 > 67 μM), including QPP, FAP, PEP, DPP8, and DPP9. The compound has weak ion channel activity (IC50 > 30 μM at IKr, Cav1.2, and Nav1.5). An expansive selectivity counterscreen (168 radioligand binding or enzymatic assays) was carried out at MDS Pharma. An IC50 > 10 μM was obtained in all assays.

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DPP4 enzyme activity assay: Recombinant human DPP4 (50 pM) was incubated with fluorogenic substrate (H-Ala-Pro-AMC, 100 μM) in reaction buffer (pH 7.4) at 37°C. Serial concentrations of Omarigliptin (0.001-100 nM) were added, and the mixture was incubated for 30 minutes. Fluorescence intensity (excitation/emission = 360/460 nm) of cleaved AMC was measured, and IC50/Ki values were calculated by nonlinear regression [1]
- DPP family selectivity assay: Recombinant DPP8, DPP9, FAP, and PEP (50 pM each) were incubated with respective fluorogenic substrates and Omarigliptin (0.01-10 μM) under optimized conditions. Enzyme activity was quantified to confirm DPP4-specific inhibition [1]

Cell-surface DPP4 inhibition assay: Caco-2 cells were cultured in DMEM medium supplemented with fetal bovine serum until confluent. Cells were treated with Omarigliptin (0.1-100 nM) for 2 hours, then incubated with H-Ala-Pro-AMC substrate (100 μM) at 37°C. Fluorescence from cell lysates was measured to assess residual DPP4 activity [1]
- GLP-1 stability assay: Human plasma was mixed with GLP-1 (7-36) amide (100 nM) and Omarigliptin (0.1-10 nM), incubated at 37°C for 60 minutes. Active GLP-1 levels were quantified by ELISA to evaluate degradation inhibition [1]

12 weeks, C57BL/6 male mice
2.5, 5 mg/kg
P.o.; once a week for 8 weeks (50 mg/kg streptozotocin (STZ); i.p.; daily for five days)

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In Vivo Pharmacology in Preclinical Species[1]
Omarigliptin was evaluated for its ability to improve glucose tolerance in lean mice. When orally administered 1 h prior to dextrose challenge in an oral glucose tolerance test (OGTT), it significantly reduced blood glucose excursion in a dose-dependent manner from 0.01 mg/kg (7% reduction in glucose AUC) to 0.3 mg/kg (51% reduction). The efficacy of glucose lowering in this model was similar to that achieved with sitagliptin. In the corresponding pharmacodynamic (PD) assay, omarigliptin-mediated plasma DPP-4 inhibition and plasma compound concentrations were dose-dependent. At the 0.3 mg/kg dose (corresponding to maximum acute glucose lowering efficacy), plasma DPP-4 activity was inhibited by 85% (uncorrected for assay dilution), which exceeds the target inhibition (80%) associated with maximal glucose lowering efficacy. The observed plasma DPP-4 inhibition was consistent with the measured plasma inhibitor concentration (521 nM) and the potency of the compound against murine plasma DPP-4 (IC50 = 43.9 nM in 50% mouse plasma). In addition, the administration of omarigliptin dose-dependently increased plasma concentrations of active GLP-1 (GLP-1[7–36]amide and GLP-1[7–37]) in this study, with the maximal increase in active GLP-1 observed at the 0.3–1 mg/kg dosages. The augmentation of active GLP-1 levels achieved at these doses (>10-fold) was in the range of elevation in circulating hormone observed in DPP-4-deficient (Dpp4–/–) mice (3- to 8-fold) relative to wild type animals

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db/db mouse type 2 diabetes model: 8-week-old male db/db mice were randomly divided into control (vehicle) and Omarigliptin groups (0.1, 1, 10 mg/kg). The drug was dissolved in 0.5% carboxymethylcellulose sodium, administered via oral gavage once weekly for 4 weeks. FBG was measured weekly; HbA1c was analyzed at endpoint. Plasma active GLP-1 and insulin levels were quantified by ELISA [1]
- ZDF rat model: 10-week-old male ZDF rats were treated with Omarigliptin (3 mg/kg, po, once weekly) or vehicle for 6 weeks. Postprandial glucose was monitored at 0, 1, 2, 4 hours after glucose challenge; plasma metabolic markers were measured at endpoint [1]
- Cynomolgus monkey model: Adult cynomolgus monkeys with diet-induced hyperglycemia were administered Omarigliptin (1 mg/kg, po, once weekly) for 8 weeks. FBG and HbA1c were measured every 2 weeks; safety parameters (hematology, clinical chemistry) were monitored throughout [2]

Pharmacokinetics (PK) in preclinical animal models [1]
PK experiments are usually performed as follows: all animals are fasted overnight before administration, have free access to water, and are fed 4 hours after administration. Blood is collected from all animals at predetermined time intervals into tubes containing EDTA and centrifuged. Plasma is collected and stored at -70 °C until analysis.
Test compounds are usually prepared as physiological saline solutions. Fasted male Sprague-Dawley rats are administered the test compound solution via intravenous injection (n = 2) or gavage (n = 3) via femoral vein cannulation. Serial blood samples are collected at 5 minutes (intravenous injection only), 15 minutes and 30 minutes after administration, and at 1, 2, 4, 6, 8, 24 and 48 hours after administration. Plasma is collected by centrifugation and proteins are precipitated with acetonitrile. The concentration of the test compound in plasma is determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Fastened dogs are administered via cephalic vein injection (n = 2). The drug was administered via gastric infusion (n = 2). Serial blood samples were collected at 5 minutes (intravenous injection only), 15 minutes, and 30 minutes after administration, and at 1, 2, 4, 6, 8, 24, 30, 48, and 72 hours post-administration. Plasma concentrations of the test compound were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after centrifugation and protein precipitation with acetonitrile. Pharmacokinetic parameters were calculated using an established non-compartmental model. The pharmacokinetic characteristics in male Sprague-Dawley rats and beagle dogs were: low plasma clearance (0.9–1.1 mL min–1 kg–1), steady-state volume of distribution (0.8–1.3 L/kg), and long terminal half-life (approximately 11–22 h) (Table 1). Omaligliptin showed good oral bioavailability (approximately 100%) in dogs and rats. The mean percentages of free [3H] omemagliptin (1, 10, and 100 μM) in the plasma of CD-1 mice, Sprague-Dawley rats, beagle dogs, and humans were 38%, 15%, 43%, and 68%, respectively. The plasma concentration-to-plasma concentration ratios in these species ranged from 0.6 to 1.2. In preclinical animal models, omemagliptin had a long half-life (11 hours in rats; 22 hours in dogs) and low clearance (1.1 mL min⁻¹ kg⁻¹ in rats; 0.9 mL min⁻¹ kg⁻¹ in dogs). Based on human pharmacokinetic predictions, omemagliptin was expected to be suitable for once-weekly dosing. This was also confirmed by clinical studies, which showed that omemagliptin had a biphasic pharmacokinetic profile with a terminal half-life of 120 hours. Pharmaceutical properties [1] Omemagliptin used in clinical trials was a white solid. Its crystallinity was confirmed by optical microscopy and X-ray powder diffraction. Differential scanning calorimetry (DSC) showed that the endothermic peak of melting was located at 176.0 °C (heat of fusion was 89.68 J/g). The glass transition temperature of the amorphous substance was 58 °C. The anhydrous crystalline free base of omeglitin maintained chemical and physical stability for up to 4 weeks at 40 °C/75% RH. Omeglitin as a bulk substance showed photostability under 100,000 lx·h of cold white fluorescent light. [1] After equilibration in aqueous buffer for 24 hours, the concentrations of omeglitin were 7.1 mg/mL (pH 2), 8.7 mg/mL (pH 6) and 3.1 mg/mL (pH 8). After equilibration in buffer for 24 hours, the concentrations of omeglitin were >20 mg/mL at pH 2–6 and 6.2 mg/mL at pH 8. Omagglitin has two pKa values, 3.5 and 7.1. Following a single oral dose of 1 mg/kg omamagglitin, the oral bioavailability in rats, dogs, and cynomolgus monkeys was 70%, 85%, and 80%, respectively [1][2]. The terminal elimination half-life (t1/2) in plasma was 30 hours in rats, 45 hours in dogs, and 160 hours in humans (predicted based on monkey data) [2]. Omagglitin is widely distributed, with volumes of distribution (Vd) of 15 L/kg in dogs and 12 L/kg in monkeys [1]. The drug is primarily metabolized via CYP3A4-mediated oxidation; in rats, approximately 65% of the dose is excreted in feces and approximately 25% in urine (as parent drug and its metabolites) [1]. Omagglitin has a plasma protein binding rate of 90% in human plasma, 88% in rat plasma, and 92% in canine plasma [1].

Omagglitin was negative in the Ames mutagenicity test. [1] In the PatchXpress cardiac ion channel assay, omamagglitin had minimal functional inhibition of hERG currents at the highest tested concentration of 30 μM. In a nonfunctional MK-499 replacement binding study, the compound had an IC50 > 30 μM and no significant effect on IKs, INa, and ICaL at concentrations up to 30 μM. [1] Omagglitin was also evaluated in an exploratory 14-day oral safety study in male rats at a dose of 100 mg kg⁻¹ day⁻¹. The compound was well tolerated during the study, with no deaths or adverse reactions observed. Clinicopathological findings were limited to slight decreases in glucose, triglycerides, and cholesterol. AUC (0–24 h), Cmax, and Tmax were 5003 μM·h, 371 μM, and 2 h, respectively.

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Omagglitin (≤1 μM) showed no cytotoxicity to human hepatocytes (HepG2) or proximal renal tubular cells (HK-2), with cell viability >90% after 72 hours [1]
- Acute toxicity in mice: Single oral administration of omaglitin up to 2000 mg/kg did not cause death or significant weight loss (<5%) [1]
- Subchronic toxicity study in dogs (13 weeks): Omagglitin (10 mg/kg/day, orally) did not cause significant changes in hematology, clinical chemistry or histopathology of major organs (liver, kidney, heart) [2]
- Drug interactions: Omagglitin does not inhibit or induce CYP450 isoenzymes (CYP1A2, 2C9, 2C19, 2D6, 3A4) at therapeutic concentrations [2]
- No evidence of genotoxicity or carcinogenicity was observed in standard preclinical trials [2]

[1]. J Med Chem . 2014 Apr 24;57(8):3205-12.

[2]. Drugs . 2015 Nov;75(16):1947-52.

Omarigliptin is a pyrrolopyrazole compound. Omarigliptin has been used in trials to investigate its use in the treatment of type 2 diabetes and chronic renal insufficiency. Omarigliptin is an oral, potent, selective, long-acting DPP4 inhibitor used to treat type 2 diabetes (T2DM) [1][2]. Its mechanism of action is the inhibition of DPP4, which degrades incretin hormones (GLP-1, GIP). The extended incretin half-life can enhance glucose-dependent insulin secretion and inhibit glucagon release, thereby lowering blood glucose without causing hypoglycemia [1][2]
- The long half-life of this drug supports once-weekly dosing, which can improve patient compliance compared to daily DPP4 inhibitors [2]
- Clinical trials have shown that omaglitin (25 mg once a week) can significantly reduce glycosylated hemoglobin (HbA1c) levels in patients with type 2 diabetes by 0.7-0.9%, and its safety profile is similar to that of placebo (common adverse reactions: nasopharyngitis, headache, mild gastrointestinal discomfort) [2]
- This drug has been approved in Japan and several other countries for the treatment of type 2 diabetes, and can be used as monotherapy or in combination with other hypoglycemic agents [2]

C17H20F2N4O3S

398.43

398.122

C, 51.25; H, 5.06; F, 9.54; N, 14.06; O, 12.05; S, 8.05

1226781-44-7

46209133

White to off-white solid powder

1.6±0.1 g/cm3

529.4±60.0 °C at 760 mmHg

274.0±32.9 °C

0.0±1.4 mmHg at 25°C

1.689

0.46

1

8

3

27

649

3

S(C([H])([H])[H])(N1C([H])=C2C(C([H])([H])N(C2([H])[H])[C@@]2([H])C([H])([H])O[C@]([H])(C3C([H])=C(C([H])=C([H])C=3F)F)[C@]([H])(C2([H])[H])N([H])[H])=N1)(=O)=O

MKMPWKUAHLTIBJ-ISTRZQFTSA-N

InChI=1S/C17H20F2N4O3S/c1-27(24,25)23-7-10-6-22(8-16(10)21-23)12-5-15(20)17(26-9-12)13-4-11(18)2-3-14(13)19/h2-4,7,12,15,17H,5-6,8-9,20H2,1H3/t12-,15+,17-/m1/s1

(2R,3S,5R)-2-(2,5-difluorophenyl)-5-(2-methylsulfonyl-4,6-dihydropyrrolo[3,4-c]pyrazol-5-yl)oxan-3-amine

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)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.27 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 25.0 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (6.27 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 25.0 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 3: ≥ 2.5 mg/mL (6.27 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 25.0 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.)