Linagliptin

Description

Linagliptin (trade names Tradjenta and Trajetna) is an inhibitor of dipeptidyl peptidase-4 (DPP-4) that was approved by the U.S. FDA in May 2011 for the treatment of Type 2 diabetes along with diet and exercise. Linagliptin (BI-1356) has been described as a potent highly selective, slow-off rate and long acting inhibitor of DPP-4. Linagliptin arose from optimization efforts of xanthine-based DPP-4 inhibitors with the initial lead identified from an HTS campaign. After optimizing the activity of the initial micromolar lead, two issues that needed to be addressed were activity for hERG and muscarinic receptor M1. Introduction of a butynyl group at the N7 position of the xanthine ring gave much reduced M1 affinity with no measureable hERG activity. Linagliptin inhibits DPP-4 with an IC₅₀=1 nM and is highly selective (>10,000-fold) against DPP-8 and DPP-9. Linagliptin shows no interactions with CYPs up to 50 mM. The described synthesis of linagliptin starts with 8-bromoxanthine, which is alkylated at the N-7 position to introduce the butyne group, followed by alkylation of the N-1 group to introduce the methyl-quinazoline group. Displacement of the bromide with (R)-Boc-3-amino-piperidine followed by deprotection gives linagliptin. When administered to db/db mice orally, linagliptin dose dependently reduced glucose excursion from 0.1 mg/kg (15% inhibition) to 1 mg/kg (66% inhibition).

The Uses of Linagliptin

Labeled Linagliptin, intended for use as an internal standard for the quantification of Linagliptin by GC- or LC-mass spectrometry.

Indications

Linagliptin is indicated for the treatment of type II diabetes in addition to diet and exercise. It should not be used to treat type I diabetes or in diabetic ketoacidosis. An extended-release combination product containing empagliflozin, linagliptin, and metformin was approved by the FDA in January 2020 for the improvement of glycemic control in adults with type 2 diabetes mellitus when used adjunctively with diet and exercise.

Background

Linagliptin is a DPP-4 inhibitor developed by Boehringer Ingelheim for the treatment of type II diabetes . Linagliptin differs from other DPP-4 inhibitors in that it has a non-linear pharmacokinetic profile, is not primarily eliminated by the renal system, and obeys concentration dependant protein binding. Linagliptin was approved by the FDA on May 2, 2011.

Pharmacokinetics

A 5mg oral dose of linagliptin results in >80% inhibition of dipeptidyl peptidase 4 (DPP-4) for ≥24 hours. Inhibition of DPP-4 increases the concentration of glucagon-like peptide 1 (GLP-1), leading to decreased glycosylated hemoglobin and fasting plasma glucose.

Metabolism

An oral dose of linagliptin is excreted primarily in the feces. 90% of an oral dose is excreted unchanged in the urine and feces. The predominant metabolite in the plasma is CD1790 and the predominant metabolite recovered after excretion was M489(1). Other metabolites are produced through oxidation, oxidative degradation, N-acetylation, glucuronidation, and cysteine adduct formation. Other metabolites have been identified through mass spectrometry though no structures were determined. Metabolism of linagliptin is mediated by cytochrome P450 3A4, aldo-keto reductases, and carbonyl reductases.

Absorption

Oral bioavailability of linagliptin is 30%.

Toxicity

No dosage adjustment is necessary based on race, age, weight, sex, renal impairment, or hepatic impairment.
Studies of efficacy and safety in pediatric populations were not included in the original drug approval but recent clinical trials show linagliptin to be well tolerated in patients 10 to 18 years old.
Animal studies showed an increased risk of lymphoma in female rats at over 200 times the clinical dose. Aside from this effect, linagliptin was not shown to be mutagenic, clastogenic, or have an effect on fertility.