Dose-proportionality of a final market image sitagliptin formulation, an oral dipeptidyl peptidase-4 inhibitor, in healthy volunteers

Bioequivalence Evaluation in Healthy Volunteers: New Generic Formulations of Sitagliptin and Sitagliptin-Metformin Fixed-Dose Combination Compared with the Originator Products

INTRODUCTION

Three studies compared the bioequivalence (BE) of new generic tablet formulations of sitagliptin (100 mg; fasting) and the fixed-dose combination (FDC) of sitagliptin/metformin (50/850 mg, 50/1000 mg; both fed) in healthy volunteers with the same tablet strengths of the reference products Januvia and Janumet.

METHODS

The study design was open-label, single-dose, randomized with two-way crossover periods. Blood sampling was performed for 72/48 h in the sitagliptin/FDC studies, respectively. Primary pharmacokinetic (PK) parameters for sitagliptin and metformin were area under the plasma concentration-time curve from time 0 to last timepoint of measurable concentration (AUC_0-t) and maximum plasma concentration (C_max). Test (T) and reference (R) formulations proved bioequivalent if 90% confidence interval (CI) of geometric least-squares mean ratio for AUC_0-t and C_max were within BE acceptance range of 80.00-125.00%. Safety evaluations included vital signs, clinical laboratory tests, and adverse events (AEs).

RESULTS

Treated/evaluable volunteers for BE per study were: 30/28 (sitagliptin 100 mg), 26/25 (FDC 50/850 mg), and 26/24 (FDC 50/1000 mg). The 90% CI of the geometric means of T/R ratios for primary PK parameters were within predefined BE limits: CI for AUC_0-t and C_max were 95.83-100.37% and 91.85-109.56% (sitagliptin 100 mg); 100.84-103.69% and 93.44-105.10% (FDC 50/850 mg), and 101.26-105.20% and 98.71-112.89% (FDC 50/1000 mg); respective values for metformin were 94.23-101.89% and 91.66-99.38% (FDC 50/850 mg) and 98.45-104.89% and 96.79-105.62% (FDC 50/1000 mg). All AEs were nonserious, transient, and mostly mild. Safety evaluations did not reveal any relevant difference between T and R formulations.

CONCLUSIONS

The new generic tablet formulations of sitagliptin 100 mg and the FDCs sitagliptin/metformin 50/850 mg and 50/1000 mg demonstrated bioequivalence to originator reference products. Therefore, the new products are expected to provide efficacy and tolerability similar to those of the reference products in the treatment of patients with type 2 diabetes (T2D).

TRIAL REGISTRATION

EudraCT EU Clinical Trials Registry (2014-005437-31); ClinicalTrials.gov Registry (NCT05549570 and NCT05549583, both retrospectively registered on 20 September 2022).

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Sitagliptin Phosphate Monohydrate

Sitagliptin is an antihyperglycemic drug used in adults for the treatment of diabetes Type 2. Literature data and in-house experiments were applied in this monograph to assess whether methods based on the Biopharmaceutics Classification System (BCS) could be used to assess the bioequivalence of solid immediate-release (IR) oral dosage forms containing sitagliptin phosphate monohydrate, as an alternative to a pharmacokinetic study in human volunteers. The solubility and permeability characteristics of sitagliptin were reviewed according to the BCS, along with dissolution, therapeutic index, therapeutic applications, pharmacokinetics, pharmacodynamic characteristics, reports of bioequivalence (BE) / bioavailability problems, data on interactions between the drug and excipients and other data germane to the subject. All data reviewed in this monograph unambiguously support classification of sitagliptin as a BCS Class 1 drug. In light of its broad therapeutic index and lack of severe adverse effects, the clinical risks associated with moderately supraoptimal doses were deemed inconsequential, as were the risks associated with moderately suboptimal doses. Taking all evidence into consideration, it was concluded that the BCS-based biowaiver can be implemented for solid IR oral drug products containing sitagliptin phosphate monohydrate, provided (a) the test product is formulated solely with excipients commonly present in solid IR oral drug products approved in ICH or associated countries and used in amounts commonly applied in this type of product, (b) data in support of the BCS-based biowaiver are obtained using the methods recommended by the WHO, FDA, EMA or ICH and (c) the test product and the comparator product (which is the innovator product in this case) meet all in vitro dissolution specifications provided in the WHO, FDA, EMA or ICH guidance.

A Physiologically-Based Quantitative Systems Pharmacology Model of the Incretin Hormones GLP-1 and GIP and the DPP4 Inhibitor Sitagliptin

Incretin hormones glucagon‐like peptide‐1 (GLP‐1) and glucose‐dependent insulinotropic polypeptide (GIP) play a major role in regulation of postprandial glucose and the development of type 2 diabetes mellitus. The incretins are rapidly metabolized, primarily by the enzyme dipeptidyl‐peptidase 4 (DPP4), and the neutral endopeptidase (NEP), although the exact metabolization pathways are unknown. We developed a physiologically‐based (PB) quantitative systems pharmacology model of GLP‐1 and GIP and their metabolites that describes the secretion of the incretins in response to intraduodenal glucose infusions and their degradation by DPP4 and NEP. The model describes the observed data and suggests that NEP significantly contributes to the metabolization of GLP‐1, and the traditional assays for the total GLP‐1 and GIP forms measure yet unknown entities produced by NEP. We further extended the model with a PB pharmacokinetics/pharmacodynamics model of the DPP4 inhibitor sitagliptin that allows predictions of the effects of this medication class on incretin concentrations.

Pharmacokinetic Interactions Between Gemigliptin and Metformin, and Potential Differences in the Pharmacokinetic Profile of Gemigliptin Between the Mexican and Korean Populations: A Randomized, Open-label Study in Healthy Mexican Volunteers

PURPOSE

The aim of this study was to assess the pharmacokinetic interactions between a newly developed dipeptidyl peptidase (DPP)-4 inhibitor, gemigliptin, and metformin in healthy Mexican male volunteers, and the differences in the pharmacokinetic profile of gemigliptin between Korean and Mexican healthy volunteers.

METHODS

This was a multiple-dose, randomized, open-label, 3-way, 3-period crossover study. Subjects were randomized to 1 of 3 treatment sequences and received gemigliptin 50mg once a day, metformin1000mg BID, or both drugs during a 7-day treatment period, and underwent sampling for pharmacokinetic analysis and tolerability assessments. Point estimates and 90% CIs of C_max,ss and AUCτ,ss least squares mean (LSM) ratios of the concurrent administration of gemigliptin + metformin to the administration of monotherapy with either drug were obtained, and the pharmacokinetic profile of gemigliptin observed was compared with that in healthy Korean volunteers studied during the initial development of gemigliptin.

FINDINGS

The coadministration of gemigliptin + metformin did not affect the pharmacokinetic characteristics of gemigliptin (LSM ratio [90% CI] for C_max,ss and AUC_τ,ss: 0.98 [0.87-1.10] and 0.94 [0.91-0.98], respectively) or metformin (LSM ratio [90% CI] for C_max,ss and AUC_τ,ss: 0.97 [0.88-1.08] and 1.02 [0.93-1.12], respectively) when administered as monotherapy and was well tolerated. In contrast with Korean healthy volunteers, Mexican subjects showed a modestly higher gemigliptin exposure (LSM ratio [90% CI] for AUC_τ,ss: 1.22 [1.14-1.31]).

IMPLICATIONS

The results of this study support, in ethnically different populations, the absence of drug-drug interactions between gemigliptin and metformin previously shown in Korean healthy volunteers. Considering the flat effect-concentration curve and wide therapeutic range of gemigliptin, the pharmacokinetic profile of gemigliptin observed in healthy Mexican and Korean subjects suggests that gemigliptin use in Mexican patients may be associated with outcomes, in terms of efficacy and tolerability, similar to those observed in the Korean population. ClinicalTrials.gov identifier: NCT03310749.

Sitagliptin: a review of its use in patients with type 2 diabetes mellitus

Sitagliptin (Januvia(®), Xelevia™, Glactiv(®), Tesavel(®)) is an orally administered, potent and highly selective inhibitor of dipeptidyl peptidase-4 (DPP-4) and was the first agent of its class to be approved for use in the management of adults with type 2 diabetes. Numerous randomized placebo- or active comparator-controlled trials have demonstrated the efficacy of sitagliptin in terms of improving glycaemic control in patients with type 2 diabetes, including its use as monotherapy, initial combination therapy (usually with fixed-dose combinations of sitagliptin/metformin), or add-on therapy to metformin or to other antihyperglycaemic drugs, with or without metformin. The primary endpoint of the clinical trials was the reduction from baseline in glycosylated haemoglobin (HbA1c), although sitagliptin also showed beneficial effects for other endpoints, such as the proportion of patients who achieved target HbA1c, and reductions from baseline in fasting plasma glucose (FPG) levels and 2-h postprandial glucose (PPG) levels. Sitagliptin was generally well tolerated in clinical trials, had a low risk of hypoglycaemia (although this depends on background therapy) and had a neutral effect on body weight. Despite concerns regarding a possible increased risk of rare pancreatic adverse events (e.g. pancreatitis) with glucagon-like peptide-1 (GLP-1)-based therapies, such as GLP-1 receptor agonists and DPP-4 inhibitors, no causal association has been found; regulators in Europe recently conducted a review of available data, concluding that there is little evidence that these drugs could cause pancreatic inflammation or pancreatic cancer. A similar review is planned in the USA and postmarketing surveillance will continue. Thus, oral sitagliptin is an effective and generally well tolerated treatment option for the management of patients with type 2 diabetes.

Modelling the sitagliptin effect on dipeptidyl peptidase-4 activity in adults with haematological malignancies after umbilical cord blood haematopoietic cell transplantation

BACKGROUND AND OBJECTIVES

Dipeptidyl peptidase-4 (DPP4) inhibition is a potential strategy to increase the engraftment rate of haematopoietic stem/progenitor cells. A recent clinical trial using sitagliptin, a DPP4 inhibitor approved for type 2 diabetes mellitus, has been shown to be a promising approach in adults with haematological malignancies after umbilical cord blood (UCB) haematopoietic cell transplantation (HCT). On the basis of data from this clinical trial, a semi-mechanistic model was developed to simultaneously describe DPP4 activity after multiple doses of sitagliptin in subjects with haematological malignancies after a single-unit UCB HCT.

METHODS

The clinical study included 24 patients who received myeloablative conditioning followed by oral sitagliptin with single-unit UCB HCT. Using a nonlinear mixed-effects approach, a semi-mechanistic pharmacokinetic-pharmacodynamic model was developed to describe DPP4 activity from these trial data, using NONMEM version 7.2 software. The model was used to drive Monte Carlo simulations to probe the various dosage schedules and the attendant DPP4 response.

RESULTS

The disposition of sitagliptin in plasma was best described by a two-compartment model. The relationship between sitagliptin concentrations and DPP4 activity was best described by an indirect response model with a negative feedback loop. Simulations showed that twice daily or three times daily dosage schedules were superior to a once daily schedule for maximal DPP4 inhibition at the lowest sitagliptin exposure.

CONCLUSION

This study provides the first pharmacokinetic-pharmacodynamic model of sitagliptin in the context of HCT, and provides a valuable tool for exploration of optimal dosing regimens, which are critical for improving the time to engraftment in patients after UCB HCT.

Advances in the treatment of type 2 diabetes mellitus

There is a rising worldwide prevalence of diabetes, especially type 2 diabetes mellitus (T2DM), which is one of the most challenging health problems in the 21st century. The associated complications of diabetes, such as cardiovascular disease, peripheral vascular disease, stroke, diabetic neuropathy, amputations, renal failure, and blindness result in increasing disability, reduced life expectancy, and enormous health costs. T2DM is a polygenic disease characterized by multiple defects in insulin action in tissues and defects in pancreatic insulin secretion, which eventually leads to loss of pancreatic insulin-secreting cells. The treatment goals for T2DM patients are effective control of blood glucose, blood pressure, and lipids (if elevated) and, ultimately, to avert the serious complications associated with sustained tissue exposure to excessively high glucose concentrations. Prevention and control of diabetes with diet, weight control, and physical activity has been difficult. Treatment of T2DM has centered on increasing insulin levels, either by direct insulin administration or oral agents that promote insulin secretion, improving sensitivity to insulin in tissues, or reducing the rate of carbohydrate absorption from the gastrointestinal tract. This review presents comprehensive and up-to-date information on the mechanism(s) of action, efficacy, pharmacokinetics, pleiotropic effects, drug interactions, and adverse effects of the newer antidiabetic drugs, including (1) peroxisome proliferator-activated-receptor-γ agonists (thiazolidinediones, pioglitazone, and rosiglitazone); (2) the incretin, glucagon-like peptide-) receptor agonists (incretin-mimetics, exenatide. and liraglutide), (3) inhibitors of dipeptidyl-peptidase-4 (incretin enhancers, sitagliptin, and vildagliptin), (4) short-acting, nonsulfonylurea secretagogue, meglitinides (repaglinide and nateglinide), (5) amylin anlog-pramlintide, (6) α-glucosidase inhibitors (miglitol and voglibose), and (7) colesevelam (a bile acid sequestrant). In addition, information is presented on drug candidates in clinical trials, experimental compounds, and some plants used in the traditional treatment of diabetes based on experimental evidence. In the opinion of this reviewer, therapy based on orally active incretins and incretin mimetics with long duration of action that will be efficacious, preserve the β-cell number/function, and block the progression of diabetes will be highly desirable. However, major changes in lifestyle factors such as diet and, especially, exercise will also be needed if the growing burden of diabetes is to be contained.

Lack of pharmacokinetic interaction between dapagliflozin, a novel sodium-glucose transporter 2 inhibitor, and metformin, pioglitazone, glimepiride or sitagliptin in healthy subjects

AIMS

Dapagliflozin increases urinary glucose excretion by selectively inhibiting renal sodium-glucose transporter 2, an insulin-independent mechanism of action that may be complementary to that of other oral antidiabetes drugs. The current studies assessed the potential for pharmacokinetic (PK) interaction between dapagliflozin and pioglitazone, metformin, glimepiride or sitagliptin in healthy subjects following single-dose administration.

METHODS

In open-label, randomized, three-period, three-treatment crossover studies, 24 subjects received 50 mg dapagliflozin, 45 mg pioglitazone or the combination, while 18 subjects received 20 mg dapagliflozin, 1000 mg metformin or the combination. In an open-label, randomized, five-period, five-treatment, unbalanced crossover study, 18 subjects first received 20 mg dapagliflozin, 4 mg glimepiride or the combination, and afterward 100 mg sitagliptin or sitagliptin plus 20 mg dapagliflozin. Blood samples were taken over 72 h of each treatment period. Lack of PK interaction was defined as the ratio of geometric means and 90% confidence interval (CI) for combination:monotherapy being within the range of 0.80-1.25.

RESULTS

Co-administration of dapagliflozin with pioglitazone, metformin, glimepiride or sitagliptin had no effect on dapagliflozin maximum plasma concentration (C(max) ) or area under the plasma concentration-time curve (AUC). Similarly, dapagliflozin did not affect the C(max) or AUC for the co-administered drug, except for slight extensions of the 90% CI for the ratio of geometric means for glimepiride AUC (upper limit 1.29) and pioglitazone C(max) (lower limit 0.75). All monotherapies and combination therapies were well tolerated.

CONCLUSION

Dapagliflozin can be co-administered with pioglitazone, metformin, glimepiride or sitagliptin without dose adjustment of either drug.

Pharmacokinetics of dipeptidylpeptidase-4 inhibitors

Type 2 diabetes (T2DM) is a complex disease combining defects in insulin secretion and insulin action. New compounds have been developed for improving glucose-induced insulin secretion and glucose control, without inducing hypoglycaemia or weight gain. Dipeptidylpeptidase-4 (DPP-4) inhibitors are new oral glucose-lowering agents, so-called incretin enhancers, which may be used as monotherapy or in combination with other antidiabetic compounds. Sitagliptin, vildaglipin and saxagliptin are already on the market in many countries, either as single agents or in fixed-dose combined formulations with metformin. Other DPP-4 inhibitors, such as alogliptin and linagliptin, are currently in late phase of development. The present paper summarizes and compares the main pharmacokinetics (PK) properties, that is, absorption, distribution, metabolism and elimination, of these five DPP-4 inhibitors. Available data were obtained in clinical trials performed in healthy young male subjects, patients with T2DM, and patients with either renal insufficiency or hepatic impairment. PK characteristics were generally similar in young healthy subjects and in middle-aged overweight patients with diabetes. All together gliptins have a good oral bioavailability which is not significantly influenced by food intake. PK/pharmacodynamics characteristics, that is, sufficiently prolonged half-life and sustained DPP-4 enzyme inactivation, generally allow one single oral administration per day for the management of T2DM; the only exception is vildagliptin for which a twice-daily administration is recommended because of a shorter half-life. DPP-4 inhibitors are in general not substrates for cytochrome P450 (except saxagliptin that is metabolized via CYP 3A4/A5) and do not act as inducers or inhibitors of this system. Several metabolites have been documented but most of them are inactive; however, the main metabolite of saxagliptin also exerts a significant DPP-4 inhibition and is half as potent as the parent compound. Renal excretion is the most important elimination pathway, except for linagliptin whose metabolism in the liver appears to be predominant. PK properties of gliptins, combined with their good safety profile, explain why no dose adjustment is necessary in elderly patients or in patients with mild to moderate hepatic impairment. As far as patients with renal impairment are concerned, significant increases in drug exposure for sitagliptin and saxagliptin have been reported so that appropriate reductions in daily dosages are recommended according to estimated glomerular filtration rate. The PK characteristics of DPP-4 inhibitors suggest that these compounds are not exposed to a high risk of drug-drug interactions. However, the daily dose of saxagliptin should be reduced when coadministered with potent CYP 3A4 inhibitors. In conclusion, besides their pharmacodynamic properties leading to effective glucose-lowering effect without inducing hypoglycaemia or weight gain, DPP-4 inhibitors show favourable PK properties, which contribute to a good efficacy/safety ratio for the management of T2DM in clinical practice.

Sitagliptin: a review of its use in the management of type 2 diabetes mellitus

Sitagliptin (Januvia, Glactiv(R), Tesavel(R)) is a dipeptidyl peptidase-4 inhibitor indicated for the treatment of type 2 diabetes mellitus. Oral sitagliptin as monotherapy or combination therapy was generally well tolerated and improved glycaemic control in well designed clinical trials in patients with type 2 diabetes. Glycosylated haemoglobin (HbA(1c)) levels were significantly reduced with sitagliptin monotherapy relative to voglibose monotherapy or placebo, and with sitagliptin as initial combination therapy with metformin or pioglitazone relative to monotherapy with these agents or placebo. Moreover, sitagliptin monotherapy was noninferior to metformin monotherapy in terms of the reduction in HbA(1c) levels. Significant reductions in HbA(1c) levels, relative to background therapy, were also observed with sitagliptin add-on therapy to ongoing treatment with thiazolidinediones, sulfonylureas or insulin with or without metformin, or metformin alone. In terms of the reduction in HbA(1c) levels as add-on treatment to metformin, sitagliptin was noninferior to glipizide and generally did not differ from rosiglitazone, and as add-on treatment to pioglitazone, it did not differ significantly from metformin. Sitagliptin had a low risk of hypoglycaemia (except when used in combination with agents that may be associated with hypoglycaemia, such as sulfonylureas or insulin) and was generally weight-neutral. Although additional comparative data and longer-term studies with glycaemic and clinical outcomes are required to definitively position sitagliptin relative to other antihyperglycaemic agents, current evidence suggests that it is a useful treatment option for patients with type 2 diabetes, with potential advantages including oral administration, a generally weight-neutral effect and a low risk of hypoglycaemia.

Initial combination therapy with sitagliptin, a dipeptidyl peptidase-4 inhibitor, and metformin for patients with Type 2 diabetes mellitus

The two incretin hormones, glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide potentiate nutrient-dependent insulin secretion following meal ingestion. Metabolic control can be improved markedly by administration of exogenous GLP-1, but the native peptide is almost immediately degraded by the enzyme dipeptidyl peptidase (DPP)-4 and, therefore, has little clinical value. Oral formulations that inhibit DPP-4, thereby prolonging the duration of endogenous incretin action, have, therefore, been developed. Sitagliptin, a once-daily, orally active, competitive and fully reversible inhibitor of DPP-4, was, as first in its class, introduced to the market as Januvia™. Recently, the US FDA approved initial combination therapy with sitagliptin and metformin (Janumet™) in order to help more patients with Type 2 diabetes mellitus get closer to accepted glycemic control targets, as recommended by standard guidelines. This article reviews initial treatment with Janumet as an alternative to monotherapy.