Safety, tolerability, pharmacokinetics and pharmacokinetic-pharmacodynamic modeling of cetagliptin in patients with type 2 diabetes mellitus.

Aims: To evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of cetagliptin (CAS number:2243737-33-7) in Chinese patients with type 2 diabetes mellitus (T2DM). A population PK/PD model was developed to quantify the PK and PD characteristics of cetagliptin in patients. Materials and methods: 32 Chinese adults with T2DM were enrolled in this study. The subjects were randomly assigned to receive either cetagliptin (50 mg or 100 mg), placebo, or sitagliptin (100 mg) once daily for 14 days. Blood samples were collected for PK and PD analysis. Effects on glucose, insulin, C-peptide, and glucagon were evaluated following an oral glucose tolerance test (OGTT) (day15). Effects on HbA1c and glycated albumin (GA), and safety assessments were also conducted. Meanwhile, a population PK/PD model was developed by a sequential two-step analysis approach using Phoenix. Results: Following multiple oral doses, cetagliptin was rapidly absorbed and the mean half-life were 34.9-41.9 h. Steady-state conditions were achieved after 1 week of daily dosing and the accumulation was modest. The intensity and duration of DPP-4 inhibition induced by 50 mg cetagliptin were comparable with those induced by sitagliptin, and 100 mg cetagliptin showed a much longer sustained DPP-4 inhibition (≥80%) than sitagliptin. Compared with placebo group, plasma active GLP-1 AUEC0-24h increased by 2.20- and 3.36-fold in the 50 mg and 100 mg cetagliptin groups. A decrease of plasma glucose and increase of insulin and C-peptide were observed following OGTT in cetagliptin groups. Meanwhile, a tendency of reduced GA was observed, whereas no decreasing trend was observed in HbA1c. All adverse events related to cetagliptin and sitagliptin were assessed as mild. A population PK/PD model was successfully established. The two-compartment model and Sigmoid-Emax model could fit the observed data well. Total bilirubin (TBIL) was a covariate of volume of peripheral compartment distribution (V2), and V2 increased with the increase of TBIL. Conclusions: Cetagliptin was well tolerated, inhibited plasma DPP-4 activity, increased plasma active GLP-1 levels, and exhibited a certain trend of glucose-lowering effect in patients with T2DM. The established population PK/PD model adequately described the PK and PD characteristics of cetagliptin.

A randomized, double-blind, placebo controlled, phase 3 trial to evaluate the efficacy and safety of cetagliptin added to ongoing metformin therapy in patients with uncontrolled type 2 diabetes with metformin monotherapy.

AIM: This trial was designed to assess the efficacy and safety of cetagliptin added to metformin in Chinese patients with type 2 diabetes who had inadequate glycaemic control with metformin monotherapy. METHODS: In total, 446 patients with type 2 diabetes on metformin monotherapy were randomized to receive the addition of once-daily cetagliptin 100 mg, cetagliptin 50 mg and placebo in a 2:2:1 ratio for 24-week double-blind treatment. At week 24, patients initially randomized to cetagliptin 50 mg and placebo were switched to cetagliptin 100 mg for 28 weeks open-label treatment. The primary endpoint was the change in haemoglobin A1c (HbA1c) from baseline, and the efficacy analyses were based on an all-patients-treated population using an analysis of co-variance. RESULTS: After 24 weeks, both add-on therapies led to greater glycaemic control. Reductions in HbA1c from baseline were -1.17 ± 0.794%, -1.23 ± 0.896% in cetagliptin 100 mg and 50 mg plus metformin group, respectively. No difference was observed between the cetagliptin 100 mg and 50 mg plus metformin group. Patients with higher baseline HbA1c levels (≥8.5%) experienced greater reductions in HbA1c. A significantly greater proportion of patients achieved an HbA1c <7.0% with cetagliptin 100 mg (49.4%) and cetagliptin 50 mg (51.1%) plus metformin than metformin monotherapy (14.4%). Both combination therapies also improved the homeostasis model assessment ß-function index and decreased systolic blood pressure. There was no increased risk of adverse effects with combination therapy, and both combination therapies were generally well tolerated. CONCLUSIONS: The addition of cetagliptin once daily to metformin was more efficacious and well tolerated than metformin monotherapy in Chinese patients with type 2 diabetes who had inadequate glycaemic control with metformin monotherapy.

Efficacy and safety of cetagliptin as monotherapy in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled phase 3 trial.

AIM: To assess the efficacy and safety of the dipeptidyl peptidase-4 inhibitor, cetagliptin, as monotherapy in Chinese patients with type 2 diabetes (T2D) and inadequate glycaemic control. MATERIALS AND METHODS: In total, 504 eligible patients with T2D were enrolled and randomized to cetagliptin 50 mg once daily, cetagliptin 100 mg once daily or placebo at a ratio of 2:2:1 for 24 weeks of double-blind treatment, then all patients received cetagliptin 100 mg once daily for 28 weeks of open-label treatment. The primary efficacy endpoint was the change in HbA1c level from baseline at week 24. RESULTS: After 24 weeks, HbA1c from baseline was significantly reduced with cetagliptin 50 mg (-1.08%) and cetagliptin 100 mg (-1.07%) compared with placebo (-0.35%). The placebo-subtracted HbA1c reduction was -0.72% with cetagliptin 50 mg and 100 mg. Patients with a baseline HbA1c of 8.5% or higher had a greater HbA1c reduction with cetagliptin than those patients with a baseline HbA1c of less than 8.5%. Both doses studied led to a significantly higher proportion of patients (42.3% with 100 mg and 45.0% with 50 mg) achieving an HbA1c of less than 7.0% compared with placebo (12.9%). Cetagliptin also significantly lowered fasting plasma glucose and 2-hour postmeal plasma glucose relative to placebo. The incidence of adverse experiences was similar between cetagliptin and placebo. No drug-related hypoglycaemia was reported. CONCLUSIONS: Cetagliptin monotherapy was effective and well tolerated in Chinese patients with T2D who had inadequate glycaemic control on exercise and diet.

A double-blind, randomized, placebo and positive-controlled study in healthy volunteers to evaluate pharmacokinetic and pharmacodynamic properties of multiple oral doses of cetagliptin.

AIMS: This study investigated the pharmacokinetics and pharmacodynamics properties, safety and tolerability of cetagliptin. METHODS: Forty-eight healthy subjects were enrolled in this study. Three cohorts were investigated in sequential order: 50, 100 and 200 mg cetagliptin. Positive control (sitagliptin 100 mg) was designed as open label. Blood samples were collected and analysed for pharmacokinetic and pharmacodynamic properties. Safety and tolerability were assessed throughout the study. RESULTS: Following multiple oral doses, cetagliptin was rapidly absorbed and reached peak plasma concentrations after approximately 1.0-1.5 hours. Plasma cetagliptin concentrations increased at a rate greater than dose. Accumulation of cetagliptin was modest, and steady state was generally achieved at day 5. Doses ≥50 mg of cetagliptin administered once daily will result in sustained dipeptidyl peptidase-4 (DPP-4) inhibition (≥80%). The plasma concentration giving 50% of maximum drug effect of DPP-4 inhibition for cetagliptin (5.29 ng/mL) was lower than that of sitagliptin (7.03 ng/mL). Active glucagon-like-1 peptide (GLP-1) concentrations were significantly increased in the cetagliptin groups by 2.3- to 3.1-fold at day 1 and 3.1- to 3.6-fold at steady state compared with that of placebo, and active GLP-1 concentrations were increased with increasing dose. Compared with sitagliptin, doses ≥100 mg once daily of cetagliptin produced postprandial increases in active GLP-1 level and induced to long-lasting glucose-lowering efficacy. Cetagliptin was well tolerated across all doses studied. CONCLUSION: Cetagliptin demonstrates the great potential for treatment with type 2 diabetes patients based on the inhibition of DPP-4, the increase in GLP-1 and insulin, the decrease in glucose, and might be more effective in DPP-4 inhibition than sitagliptin.

First-in-Human, Single-Ascending Dose and Food Effect Studies to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Cetagliptin, a Dipeptidyl Peptidase-4 Inhibitor for the Treatment of Type 2 Diabetes Mellitus.

BACKGROUND AND OBJECTIVES: Cetagliptin is a highly selective dipeptidyl peptidase-4 inhibitor under development to treat type 2 diabetes mellitus. This first-in-human study was conducted to characterise the pharmacokinetics, pharmacodynamics and tolerability of single-ascending oral doses of cetagliptin in healthy subjects. In addition, the effect of food on pharmacokinetics was evaluated. METHODS: Study 1 enrolled 66 healthy subjects in a double-blind, randomised, placebo-controlled, single-dose escalation study; sitagliptin was employed as a positive open-label control. Forty-four subjects were assigned to seven cohorts (cetagliptin 12.5, 25, 50, 100, 200, 300 or 400 mg); 12 subjects were assigned to the placebo group. The remaining ten subjects received sitagliptin 100 mg as the positive control. Blood, urine and faeces were collected for the pharmacokinetic analysis and determination of plasma dipeptidyl peptidase-4 inhibition, active glucagon-like peptide-1, glucose and insulin levels. In Study 2, 14 healthy subjects were assigned to a randomised, open-label, two-period crossover study, and received a single oral dose of cetagliptin 100 mg in the fasted state or after a high-fat meal, with a 14-day washout period between treatments. Blood samples were collected to evaluate the effects of food on the pharmacokinetics of cetagliptin. RESULTS: Following administration of a single oral dose, cetagliptin was rapidly absorbed, presenting a median time to maximum concentration of 1.0-3.25 h. The terminal half-life ranged between 25.8 and 41.3 h, which was considerably longer than that of sitagliptin. The area under the plasma concentration-time curve was approximately dose proportional between 25 mg and 400 mg, and the increase in maximum concentration was greater than dose proportional. The unchanged drug was mainly excreted in the urine (27.2-46.2% of dose) and minimally via the faeces (1.4% of dose). Dipeptidyl peptidase-4 inhibition, an increase in active glucagon-like peptide-1 and a slight decrease in blood glucose were observed, whereas insulin was not significantly altered when compared with placebo. The weighted average dipeptidyl peptidase-4 inhibition by cetagliptin 100 mg was higher than that mediated by sitagliptin 100 mg. Cetagliptin was well tolerated up to a single oral dose of 400 mg. No food effects were noted. CONCLUSIONS: Cetagliptin inhibited plasma dipeptidyl peptidase-4 activity, increased levels of active glucagon-like peptide-1 and was well tolerated at single doses up to 400 mg, eliciting no dose-limiting toxicity in healthy volunteers. Food did not affect the pharmacokinetics of cetagliptin. CLINICAL TRIAL REGISTRATION: The studies were registered at http://www.chinadrugtrials.org.cn (Nos. CTR20180167 and CTR20181331).

Study on the relevance between beany flavor and main bioactive components in Radix Astragali.

Beany flavor is a traditional sensory indicator for evaluating the quality of Radix Astragali (RA or "Huangqi" in Chinese). A RA root with a strong beany flavor is considered to be good quality in Chinese medicine. However, there is neither a study reporting volatile compounds contributing to RA beany flavor nor the relevance between beany flavor and the quality of RA. In this study, we assessed the quantification of beany flavor substance and main bioactive metabolites. The results showed that hexanal was a major volatile component contributing to the beany flavor in RA. The value of hexanal was significantly related to the origin and growth age of RA, indicating that the component could be used as a volatile indicator for the distinction of RA. Statistical analysis further demonstrated that hexanal, astragaloside IV, and total polysaccharides were primary indicators and total isoflavonoids, astragalosides, calycosin, and formononetin were the secondary indicators for quality control of RA. Correlation analysis showed that the level of hexanal was positively associated with the concentration of astragaloside IV and total polysaccharides. Our study demonstrated that aroma is one of the most important quality attributes of RA and will help to understand the role of aroma in quality assessment of traditional Chinese medicines.