Liraglutide
Liraglutide is a long-acting GLP-1R agonist that is administered subcutaneously, as a treatment of type 2 diabetes. Developed by Novo Nordisk and marketed under the brand name Victoza, it is 97% similar to native human GLP-1. It has palmitic acid linked to a spacer glutamic acid attached to Lys26 of the peptide.
Table 1. Basic Profile of Liraglutide
| Description | injectable anti-diabetic drug |
| Target(s) | Glucagon-like peptide 1 receptor (GLP-1R) |
| Generic Name | Liraglutide |
| Commercial Name | Victoza (US) Saxenda (US) |
| Combination Drug(s) | Xultrophy 100/3.6 (Degludec and Liraglutide; US and Europe) |
| Other Synonyms | N/A |
| IUPAC Name | Liraglutide is a synthetic peptide (see the amino acid sequence below) |
| 3D Structure of Liraglutide | Chain A of 4apd |
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| Figure 1. 2D and 3D structures of Liraglutide. a. The amino acid sequence of liraglutide (PubChem) is numbered from 7 to 37. The sequence schematic shown is based on information presented in Knudsen and Lau, 2019. Amino acid modifications are highlighted in yellow and the DPP4 cleave site is indicated with the scissors. b. 3D structure of Liraglutide showing one model from the NMR ensemble structure (PDB ID 4apd, Steengaard et al., 2013). Click here to interactively view the complete ensemble. |
Drug Information
Liraglutide is synthesized by attaching a C-16 fatty acid (palmitic acid) with a glutamic acid spacer on the remaining lysine residue at position 26 of the peptide precursor. The fatty acid moiety exhibits a strong, reversible binding to human serum albumin, thereby conferring protection against degradation by DPP-4 (Steensgard et al., 2013; PDB ID: 4apd)
Table 2. Chemical and physical properties of Liraglutide
| Chemical Formula | C172H265N43O51 |
| Molecular Weight | 3751.262 g/mol |
| Calculated Predicted Partition Coefficient: cLogP | No data available |
| Calculated Predicted Aqueous Solubility: cLogS | Not determined |
| Predicted Topological Polar Surface Area (TPSA) | 1510 Å2 |
Drug Target
Liraglutide functions the same way as does the native incretin hormone GLP-1 responsible for glucose-dependent insulin secretion. It competitively binds and activates the GLP-1 receptor (GLP-1R). Learn more about GLP-1 receptors.
The fatty acid moiety linked to Liraglutide confers a high albumin affinity, GLP-1R affinity, and longer duration of action against DPP-4 metabolic degradation (Lau et al., 2015). Extending the half-life also extends the pharmacokinetic properties of liraglutide - upregulating intracellular cAMP levels via GPCR-signaling pathway in elevated blood glucose concentrations, promoting insulin release, and attenuating glucagon secretion.
Drug Target Complex
Belonging to the class B G-protein-coupled receptor, GLP-1R is a seven-transmembrane protein receptor, consisting of:
- An extracellular N-terminus that binds the C-terminal part of the incretin analog
- A seven transmembrane helical domain (TMD) with the a-helices separated by three intracellular loops and three extracellular loops
- An intracellular C-terminus that is responsible for intracellular signaling
Currently there is no experimentally determined structure of Liraglutide bound to its target protein (GLP-1). Superposing the structure of Liraglutide on the complex of GLP-1R bound to Semaglutide may give us some information about its binding.
Note that the NMR structure of Liraglutide shows that it forms a helix that can adopt conformations ranging from a straight helix to a bent or kinked one. In addition the N- and C-terminal residues also adopt multiple conformations. When bound to the GLP-1R the peptide may form a slightly different conformation than shown here. So a simple superposition of any one of the NMR models (PDB ID 4apd) in the Semaglutide bound GLP-1R structure (PDB ID 7ki0) is unlikely to show the specific interactions of Liraglutide and the receptor and is not shown here.
Pharmacologic Properties and Safety
| Features | Comment(s) | Source |
| Bioavailability (%) | 55% after subcutaneous injection | DrugBank |
| IC50 (nM) | 0.11 nM | Lau et al., 2015 |
| Ki (nM) | N/A | N/A |
| Half-life (hrs) | 8-10 hours (intravenous), 13-15 hours (subcutaneous) | Lau et al., 2015 |
| Duration of Action | 24 hours | Diabetes.co.uk |
| Absorption | N/A | N/A |
| Transporter(s) | Albumin | DrugBank |
| Metabolism | Liraglutide is endogenously metabolized in a similar manner to large proteins without a specific organ as a major route of elimination. | DrugBank |
| Excretion | 6% urine and 5% feces | DrugBank |
| AMES Test (Carcinogenic Effect) | Liraglutide was negative with and without metabolic activation in the Ames test for mutagenicity and in a human peripheral blood lymphocyte chromosome aberration test for clastogenicity. | US FDA |
| hERG Safety Test (Cardiac Effect) | No clinically meaningful changes in QTc with liraglutide at therapeutic concentrations. | Darpö et al. 2013 |
| Liver Toxicity | There have been no published reports of hepatotoxicity attributed to liraglutide therapy. Liver injury due to liraglutide is quite rare. | LiverTox |
Drug Interactions and Side Effects
| Features | Comment(s) | Source |
| Total Number of Drugs Interactions | over 250 drugs | Drugs.com |
| Major Drug Interactions | bexarotene and gatifloxacin | Drugs.com |
| Alcohol/Food Interaction(s) | moderate interaction with alcohol (ethanol) | Drugs.com |
| Disease Interaction(s) | pancreatitis (major), thyroid carcinoma (major), renal dysfunction (moderate), cardiovascular disease (moderate), depression (moderate) | Drugs.com |
| On-site Binding Side Effects | Bladder pain, bloody or cloudy urine, diarrhea, difficult or painful urination, loss of appetite | Drugs.com |
| Off-site Binding Side Effects | Headache, joint pain, muscle pains and aches, fevers or chills | Drugs.com |
| CYP Interactions | low potential for pharmacokinetic drug-drug interactions related to cytochrome P450 (CYP) | US FDA |
Regulatory Approvals/Commercial
Initially developed by Novo Nordisk, Liraglutide was approved by the US FDA in January 2010 with the commercial name Victoza. It is prescribed as a subcutaneous pen-injector and often used along with a diet and exercise regime, to help control blood glucose levels in individuals with type 2 diabetes.
A different formulation of liraglutide (Saxenda) is administered as an injection. When used in conjunction with a reduced calorie diet and exercise program it can help individuals with weight-related medical problems. Saxenda is not for treating type 1 or type 2 diabetes and is not is not a weight-loss medicine or appetite suppressant (Drugs.com). Saxenda and Victoza should not be administered together.
Novo Nordisk also developed a combination drug product called IDegLira, a combination of the GLP-1 agonist liraglutide (Victoza) and the long-acting insulin degludec (Tresiba, Novo Nordisk). The drug has been approved in the United States in November 2016 and in Europe under the brand name Xultrophy. Belonging to a new class of antidiabetic treatments that combine a basal insulin and a GLP-1R agonist, Xultophy is a once-daily combination of Tresiba (insulin degludec 100 units/mL) and Victoza (liraglutide) 3.6 mg/mL injection. In the first study, at 26 weeks, IDegLira reduced HbA1c levels by 1.91% points compared with 1.28% for liraglutide and 1.44% for insulin degludec alone ( US FDA Advisory Committee Presentation, 2016).
Links
Table 5. Links to Relevant Resources
| DrugBank | https://go.drugbank.com/drugs/DB06655 |
| Drugs.com | https://www.drugs.com/mtm/liraglutide.html |
| Food and Drugs Administration | https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/022341s027lbl.pdf |
| Liver Tox: National Institutes of Health (NIH) | https://www.ncbi.nlm.nih.gov/books/NBK548472/ |
References
Darpö, B., Sager, P., MacConell, L., Cirincione, B., Mitchell, M., Han, J., Huang, W., Malloy, J., Schulteis, C., Shen, L., Porter L. (2013) Exenatide at therapeutic and supratherapeutic concentrations does not prolong the QTc interval in healthy subjects. Br J Clin Pharmacol. 75, 979-89. https://doi.org/10.1111/j.1365-2125.2012.04416.x.
Knudsen, L.B., Lau, J. (2019) The Discovery and Development of Liraglutide and Semaglutide. Front Endocrinol (Lausanne). 10, 155. https://doi.org/10.3389/fendo.2019.00155
Lau, J., Bloch, P., Schäffer, L., Pettersson, I., Spetzler, J., Kofoed, J., Madsen, K., Knudsen, L.B., McGuire, J., Steensgaard, D.B., Strauss, H.M., Gram, D.X., Knudsen, S.M., Nielsen, F.S., Thygesen, P., Reedtz-Runge, S., and Kruse, T., (2015), Discovery of the Once-Weekly Glucagon-Like Peptide-1 (GLP-1) Analogue Semaglutide, Journal of Medicinal Chemistry 58, 7370-7380. https://doi.org/10.1021/acs.jmedchem.5b00726.
Steensgaard, D.B., Thomsen, J.K., Strauss, H., Normann, M., Ludvigsen, S. (2013). https://doi.org/10.2210/pdb4APD/pdb
Underwood, C.R., Garibay, P., Knudsen, L.B., Hastrup, S., Peters, G.H., Rudolph, R., Reedtz-Runge, S. (2010) Crystal structure of glucagon-like peptide-1 in complex with the extracellular domain of the glucagon-like peptide-1 receptor. J Biol Chem. 285, 723-30. https://doi.org/10.1074/jbc.m109.033829
US FDA Advisory Committee Presentation (2016). Insulin Degludec-Liraglutide (IDegLira) for Treatment of Patients with Type 2 Diabetes. Food and Drug Administration (FDA). https://www.accessdata.fda.gov/drugsatfda_docs/nda/2016/208583Orig1s000SumR.pdf
August 2023 Jennifer Jiang and Dr. Shuchismita Dutta; Reviewed by Dr. Joseph D. Ho
http://dx.doi.org/10.2210/rcsb_pdb/GH/DM/drugs/in/Liraglutide
