An oral substrate-like DPP-4 inhibitor used for treating diabetes. dpp4 inhibitor, onglyza, komboglyze, antidiabetic drug



Oral anti-diabetic drug


Dipeptidyl peptidase-4 (DPP-4)



Commercial Name

Onglyza (United States, Canada)

Combination Drug(s)

Komboglyze, Kombiglyze XR* (metformin & saxagliptin; Europe)

Other Synonyms

BMS 477118



Ligand Code in PDB


3D Structure of saxagliptin bound to target protein DPP-4


*Kombiglyze extended-release (XR)

Table 1. Basic profile of saxagliptin 

Figure 1. 2D Structure of Saxagliptin

2D and 3D structure of saxagliptin.

Drug Information: 

Chemical Formula


Molecular Weight

315.41 g/mol

Calculated Predicted Partition Coefficient: cLogP


Calculated Predicted Aqueous Solubility: cLogS


Solubility (in water)

2.26 mg/mL (sparingly soluble)

Predicted Topological Polar Surface Area (TPSA)

90.35 Å2

Table 2. Chemical and physical properties (DrugBank).

*Note: Predicted values may slightly vary from source to source. 

Drug Target: 

Saxagliptin is an orally active hypoglycemic (anti-DM drug) substrate-like inhibitor of dipeptidyl peptidase-4 (DPP-4) (DrugBank). In type 2 diabetes, function of the incretin system is impaired and patients are unable to properly regulate their blood glucose levels in the narrow fasting plasma glucose range of 70-100 mg/dL (American Diabetes Association, 2013). Saxagliptin inhibits DPP-4, an enzyme responsible for the breakdown of GLP-1 and GIP. By delaying the degradation of these two incretin hormones, saxagliptin extends the action of insulin while also suppressing the release of glucagon. This leads to a reduction in elevated blood glucose levels, a characteristic sign of type 2 diabetes.

Drug-Target Complex: 

Dipeptidyl peptidase-4 (DPP-4)

DPP-4 is a transmembrane glycoprotein made up of 766 amino acids and consists of five regions:

Figure 2. Overall structure of human DPP-4 monomer in ribbon representation showing the N- and C-termini and color-coded regions labeled, including cysteine-rich region (pink), the highly glycosylated region (cyan) and the catalytic domain (orange). Saxagliptin is shown as a ball-and-stick representation (PDB ID: 3bjmMetzler et al., 2008).

Because saxagliptin is a substrate-like inhibitor of DPP-4, it inhibits DPP-4 by forming a covalent but reversible complex. This class of compounds interacts covalently with the catalytically active serine hydroxyl (Ser630) and has a proline-mimetic that occupies the S1 pocket of the active site.

Figure 3. X-ray crystal structure of the DPP-4 dimer (ribbons), with bound saxagliptin (ball-and-stick). The DPP-4 monomer on the right is color-coded by region as in Figure 2 and the monomer on the left is shown as a grey ribbon (PDB ID: 3bjm; Metzler et al., 2008). Surface of the active site of DPP-4 is shown in the inset. Saxagliptin is shown in a ball-and-stick representation, color-coded by atom type (C: gray; N: blue; O: red). Selected residues in the active sites are shown in the stick representation.

The X-ray structure of DPP-4 bound to saxagliptin(PDB entry 3bjm) is shown in Figure 3. The black box denotes the location of the active site. The figure at the bottom right shows a close-up view of saxagliptin in the active site, with the S1 and S2 pockets marked.

Figure 4.Hydrogen bonding interactions (green lines) between saxagliptin (ball-and-stick) and active site residues (sticks) (PDB ID: 3bjm; Metzler et al., 2008). Figure 5. Hydrogen bonding interactions (green lines) between Diprotin A (ball-and-stick) and active site residues (sticks) (PDB ID: 1nu8; Thoma et al., 2003).

The co-crystal structure of DPP-4 and saxagliptin (Metzler et al., 2008) reveals multiple interactions of the drug with its pharmacological target, DPP-4 (Figure 4).  The major difference between the interactions of saxagliptin and the non-substrate like inhibitors (eg. sitagliptin) of DPP-4 is the formation of a covalent bond between the drug and the active-site serine. For saxagliptin, this covalent interaction is mediated through the nitrile group of the drug and hydroxyl group of Ser630. The methanopyrrolidine ring of the drug occupies the S1 pocket of the enzyme and forms van der Waals interactions with the hydrophobic side-chain residues that form the pocket; the carbonyl oxygen of saxagliptin, forms a hydrogen bond with Asn710, and the primary amine of the drug participates in hydrogen-bonding network with Try662 and Glu205 and Glu206; the adamantane hydroxyl group hydrogen bonds with the side-chain hydroxyl of Tyr547. A comparison of the co-crystal structures of DPP-4 with saxagliptin (PDB ID 3bjm, Figure 4) and DPP-4 with its substrate, Diprotin A (Ile-Pro-Ile), (PDB ID 1nu8, Figure 5) reveals that saxagliptin acts by occluding the DPP-4 active site and prevents binding of incretin hormones.

Pharmacologic Properties and Safety: 




Bioavailability (%)


(Dave, 2011)

IC50 (nM)

 50 nM

(Thomas et al., 2008)

Ki (nM)

1.3 ± 0.3 nM

(Wang et al., 2012)

Half-life (hrs)

2.2-3.8 hours

(Capuano et al., 2013)

Duration of Action

24 hours



Human intestinal absorption



multidrug resistance-associated protein 1, solute carrier organic anion transporter family member 4C1, solute carrier family 22 member 8



Cytochrome p450 3A4



~75% urine; ~22% feces

(Su et al., 2012)

AMES Test (Carcinogenic Effect)

0.7569 (non AMES toxic)


hERG Safety Test (Cardiac Effect)

0.9912 (weak inhibitor)


Liver Toxicity

No instances have been reported yet


Table 3. Pharmacokinetics: ADMET of saxagliptin

Despite having a short half-life of 2.2-3.8 hours, saxagliptin is able to maintain 24-hour glycemic control with single daily dosage due to the drug’s slow disassociation from the DPP-4 enzyme ( Post-administration of saxagliptin produced a two- or three-fold increase of GLP-1 and GIP levels, which in turn result in decreased glucagon concentrations and increased glucose-dependent insulin secretion from pancreatic β-cells (National Center for Biotechnology Information). The IC50 and Ki of saxagliptin indicate that saxagliptin is an effective competitive inhibitor of DPP-4. 

Drug Interactions and Side Effects: 

Although saxagliptin is non-carcinogenic, ≥ 5% of patients treated with saxagliptin have reported adverse effects such as upper respiratory tract infection, urinary tract infection, and headache (DrugBank). According to the National Institutes of Health, <1% of patients in clinical trials displayed elevated serum enzyme levels, and no apparent liver injury was evident. The hepatotoxicity profile of saxagliptin has yet to be published. Administration of saxagliptin did not prolong the QT interval to a clinically significant degree, and thus this drug does not seem to exhibit adverse cardiac effect.




Total Number of Drugs Interactions

731 drugs


Major Drug Interactions

bexarotene and gatifloxacin


Alcohol/Food Interaction(s)

moderate interaction with alcohol (ethanol)


Disease Interaction(s)

acute pancreatitis (major) and renal dysfunction (moderate)


On-target Side Effects

abdominal pain, upper respiratory tract infection, urinary tract infection (UTI)


Off-target Side Effects

runny/stuffy nose, sore throat, cough, headache, swelling of the face, lips, or throat; difficulty swallowing or breathing; hives, rash, itching, flaking, or peeling


CYP Interactions

CY3A4/5 inducers and inhibitors

(Capuano et al., 2013)

Table 4. Drug interactions and side effects of saxagliptin

Saxagliptin has significant drug interactions because it is extensively metabolized by CYP 3A4/5 and to a lesser extent CYP 2C8 in the liver (Dave, 2011). The major active metabolite, 5-hydroxy saxagliptin, is only 2-fold less potent than its parent molecule (Capuano et al., 2013). Although saxagliptin and its metabolites are neither inhibitors nor inducers of CYP isoforms, co-administration with strong CYP3A4/5 inducers (e.g. rifampicin) or inhibitors (e.g. ketoconazole) may alter the pharmacokinetics of saxagliptin (Capuano et al., 2013). Concomitant administration of single doses of saxagliptin with insulin secretagogues (e.g. glyburide) or insulin may cause increased risk of hypoglycemia, and thus a reduced dosage is required. Interactions with other drugs (including metformin hydrochloride, famotidine, digoxin, etc.) may alter the pharmacokinetic properties (e.g. peak plasma concentration and AUC) of saxagliptin.

Regulatory Approvals/Commercial: 

 Co-developed by Bristol-Myers Squibb and AstraZeneca and approved by the US FDA in 2009, Onglyza (saxagliptin) is prescribed as an oral medication in 2.5 or 5 mg once a day, regardless of meals (DrugBank). Onglyza may be co-administered with CYP450 3A4/5 inhibitors and concomitant use with an insulin secretagogue or with insulin may require a lower dose to minimize risk of hypoglycemia ( Dosage adjustments may be necessary if the patient has moderate or severe renal dysfunction. Both the 2.5 mg and the 5 mg Onglyza cost approximately $351.21 for 30 tablets (

Produced by the biopharmaceutical company AstraZeneca AB, Komboglyze was granted marketing authorization throughout the European Union by the Committee for Medicinal Products for Human Use (CHMP) on November 24, 2011 and contains the active substances saxagliptin and metformin. It is available as tablets (2.5 mg / 850 mg or 2.5 mg / 1,000 mg) ( Komboglyze is taken as one tablet twice a day at mealtimes. If taken in adjunct with insulin or sulfonylurea, the add-on drug dosage may need to be lowered to reduce risk of hypoglycemia ( 



Food and Drugs Administration

National Institutes of Health (NIH)

Table 5. Links to relevant resources


American Diabetes Association.

Capuano, A., Sportiello, L., Maiorino, M.I., Rossi, F., Giugliano, D., Esposito, K.. (2013). Dipeptidyl Peptidase-4 Inhibitors in Type 2 Diabetes Therapy – Focus on Alogliptin". Drug, Design, Development and Therapy, 213(7), 989-1001 doi: 10.2147/DDDT.S37647

Dave, D.J. (2011). Saxagliptin: A Dipeptidyl Peptidase-4 Inhibitor in the Treatment of Type 2 Diabetes Mellitus. Journal of Pharmacology and Pharmacotherapeutics 2(4): 230-35. doi: 10.4103/0976-500X.85934.

DrugBank: Saxagliptin. "Saxagliptin: Indications, Side Effects, Warnings from Drugs.Com". N.p., <>.


Metzler, W.J., Yanchunas, J., Weigelt, C., Kish, K., Klei, H.E., Xie, D., Zhang, Y., Corbett, M., Tamura, J.K., He, B., Hamann, L.G., Kirby, M.S., Marcinkeviciene, J. (2008). Involvement of DPP-IV Catalytic Residues in Enzyme-Saxagliptin Complex Formation. Protein Science. 17(2): 240-50. doi: 10.1110/ps.073253208.

National Institutes of Health."Saxagliptin". N.p., Web. <>.

PubChem: Saxagliptin.

Su, H., Boulton, D.W., Barros, A. Jr, Wang, L., Cao, K., Bonacorsi, S.J. Jr, Iyer, R.A., Humphreys, W.G., Christopher, L.J. (2012). Characterization of the In Vitro and In Vivo Metabolism and Disposition and Cytochrome P450 Inhibition/Induction Profile of Saxagliptin in Human. Drug Metab Dispos.  Jul;40(7):1345-56. doi: 10.1124/dmd.112.045450.

Thoma, R., Loffler, B., Stihle, M., Huber, W., Ruf, A., Hennig, M. (2003). Structural basis of proline-specific exopeptidase activity as observed in human dipeptidyl peptidase-IV. Structure. 11(8), 947-959.  doi: 10.1016/S0969-2126(03)00160-6.

Thomas, L., Eckhardt, M., Langkopf, E., Tadayyon, M., Himmelsbach, F., Mark, M. (2008). (R)-8-(3-Amino-Piperidin-1-Yl)-7-But-2-Ynyl-3-Methyl-1-(4-Methyl-Quinazolin-2-Ylmethyl)-3,7-Dihydro-Purine-2,6-Dione (BI 1356), a Novel Xanthine-Based Dipeptidyl Peptidase 4 Inhibitor, has a Superior Potency and Longer Duration of Action Compared with Other Dipeptidyl Peptidase-4 Inhibitors". Journal of Pharmacology and Experimental Therapeutics, 325(1): 175-82. doi: 10.1124/jpet.107.135723.

Wang, A., Dorso, C., Kopcho, L., Locke, G., Langish, R., Harstad, E., Shipkova, P., Marcinkeviciene, J., Hamann, L., Kirby, M.S. (2012). Potency, Selectivity and Prolonged Binding of Saxagliptin to DPP4: Maintenance of DPP4 Inhibition by Saxagliptin in Vitro and Ex Vivo When Compared To a Rapidly-Dissociating DPP4 Inhibitor". BioMed Central Pharmacology, 12(2): 1-11. doi: 10.1186/1471-2210-12-2.

Summer 2016, Jennifer Jiang, Sutapa Ghosh; Reviewed by ***