Sitagliptin 100 mg daily effect on DPP-4 inhibition and compound-specific glycemic improvement

Impact of sitagliptin on endometrial mesenchymal stem-like progenitor cells: A randomised, double-blind placebo-controlled feasibility trial

BACKGROUND

Recurrent pregnancy loss (RPL) is associated with the loss of endometrial mesenchymal stem-like progenitor cells (eMSC). DPP4 inhibitors may increase homing and engraftment of bone marrow-derived cells to sites of tissue injury. Here, we evaluated the effect of the DPP4 inhibitor sitagliptin on eMSC in women with RPL, determined the impact on endometrial decidualization, and assessed the feasibility of a full-scale clinical trial.

METHODS

A double-blind, randomised, placebo-controlled feasibility trial on women aged 18 to 42 years with a history of 3 or more miscarriages, regular menstrual cycles, and no contraindications to sitagliptin. Thirty-eight subjects were randomised to either 100 mg sitagliptin daily for 3 consecutive cycles or identical placebo capsules. Computer generated, permuted block randomisation was used to allocate treatment packs. Colony forming unit (CFU) assays were used to quantify eMSC in midluteal endometrial biopsies. The primary outcome measure was CFU counts. Secondary outcome measures were endometrial thickness, study acceptability, and first pregnancy outcome within 12 months following the study. Tissue samples were subjected to explorative investigations.

FINDINGS

CFU counts following sitagliptin were higher compared to placebo only when adjusted for baseline CFU counts and age (RR: 1.52, 95% CI: 1.32-1.75, P<0.01). The change in CFU count was 1.68 in the sitagliptin group and 1.08 in the placebo group. Trial recruitment, acceptability, and drug compliance were high. There were no serious adverse events. Explorative investigations showed that sitagliptin inhibits the expression of DIO2, a marker gene of senescent decidual cells.

INTERPRETATION

Sitagliptin increases eMSCs and decreases decidual senescence. A large-scale clinical trial evaluating the impact of preconception sitagliptin treatment on pregnancy outcome in RPL is feasible and warranted.

FUNDING

Tommy's Baby Charity.

CLINICAL TRIAL REGISTRATION

EU Clinical Trials Register no. 2016-001120-54.

Is glucagon-like peptide-1 fully protected by the dipeptidyl peptidase 4 inhibitor sitagliptin when administered to patients with type 2 diabetes?

AIM

To evaluate the relationship between plasma dipeptidyl-peptidase 4 (DPP-4) activity and its protection of glucagon-like peptide-1 (GLP-1) using the DPP-4 inhibitor sitagliptin.

METHODS

On four separate days, patients with type 2 diabetes (T2D) (n = 8; age: 59.9 ±10.8 [mean ±SD] years; body mass index [BMI]: 28.8 ±4.6 kg/m² ; glycated haemoglobin A1c [HbA1c]: 43.1 ±0.5 mmol/mol [6.6% ±1.7%]) received a 380-minute continuous intravenous infusion of GLP-1 (1.0 pmol × kg bodyweight^-1  × minutes^-1 ) and a double-blind, single-dose oral administration of sitagliptin in doses of 0 (placebo), 25, 100 and 200 mg.

RESULTS

Plasma DPP-4 activity decreased compared to baseline (placebo) with increasing doses of sitagliptin (P < .01), reaching a maximal inhibition with the 100 mg dose. Levels of intact GLP-1 increased with increasing doses of sitagliptin from placebo to 100 mg (area under curve [AUC] 7.2 [95%, CI; 12.1, 16.4] [placebo], 10.7 [16.1, 21.4] [25 mg], 11.7 [17.8, 23.6] [100 mg] nmol/L × 360 minutes [P < .01]), but no further increase in intact GLP-1 levels was observed with 200 mg of sitagliptin (11.5 [17.6, 23.4] nmol/L × 360 minutes) (P = .80).

CONCLUSION

Our findings suggest that the sitagliptin dose of 100 mg is sufficient to inhibit both plasma and membrane-bound DPP-4 activity, presumably also leading to complete protection of endogenous GLP-1 in patients with T2D.

A comparative study of the binding properties, dipeptidyl peptidase-4 (DPP-4) inhibitory activity and glucose-lowering efficacy of the DPP-4 inhibitors alogliptin, linagliptin, saxagliptin, sitagliptin and vildagliptin in mice

AIMS

Since 2006, DPP-4 inhibitors have become established therapy for the treatment of type 2 diabetes. Despite sharing a common mechanism of action, considerable chemical diversity exists amongst members of the DPP-4 inhibitor class, raising the question as to whether structural differences may result in differentiated enzyme inhibition and antihyperglycaemic activity.

METHODS

We have compared the binding properties of the most commonly used inhibitors and have investigated the relationship between their inhibitory potency at the level of the enzyme and their acute glucose-lowering efficacy.

RESULTS

Firstly, using a combination of published crystal structures and in-house data, we demonstrated that the binding site utilized by all of the DPP-4 inhibitors assessed was the same as that used by neuropeptide Y, supporting the hypothesis that DPP-4 inhibitors are able to competitively inhibit endogenous substrates for the enzyme. Secondly, we ascertained that the enzymatic cleft of DPP-4 is a relatively large cavity which displays conformational flexibility to accommodate structurally diverse inhibitor molecules. Finally, we found that for all inhibitors, irrespective of their chemical structure, the inhibition of plasma DPP-4 enzyme activity correlates directly with acute plasma glucose lowering in mice.

CONCLUSION

The common binding site utilized by different DPP-4 inhibitors enables similar competitive inhibition of the cleavage of the endogenous DPP-4 substrates. Furthermore, despite chemical diversity and a range of binding potencies observed amongst the DPP-4 inhibitors, a direct relationship between enzyme inhibition in the plasma and glucose lowering is evident in mice for each member of the classes studied.

Association of DPP-4 activity with BMD, body composition, and incident hip fracture: the Cardiovascular Health Study

There was no association of plasma DPP-4 activity levels with bone mineral density (BMD), body composition, or incident hip fractures in a cohort of elderly community-dwelling adults.

INTRODUCTION

Dipeptidyl peptidase IV (DPP-4) inactivates several key hormones including those that stimulate postprandial insulin secretion, and DPP-4 inhibitors (gliptins) are approved to treat diabetes. While DPP-4 is known to modulate osteogenesis, the relationship between DPP-4 activity and skeletal health is uncertain. The purpose of the present study was to examine possible associations between DPP-4 activity in elderly subjects enrolled in the Cardiovascular Health Study (CHS) and BMD, body composition measurements, and incident hip fractures.

METHODS

All 1536 male and female CHS participants who had evaluable DXA scans and plasma for DPP-4 activity were included in the analyses. The association between (1) BMD of the total hip, femoral neck, lumbar spine, and total body; (2) body composition measurements (% lean, % fat, and total body mass); and (3) incident hip fractures and plasma levels of DPP-4 activity were determined.

RESULTS

Mean plasma levels of DPP-4 activity were significantly higher in blacks (227 ± 78) compared with whites (216 ± 89) (p = 0.04). However, there was no significant association of DPP-4 activity with age or gender (p ≥ 0.14 for both). In multivariable adjusted models, there was no association of plasma DPP-4 activity with BMD overall (p ≥ 0.55 for all) or in gender stratified analyses (p ≥ 0.23). There was also no association of DPP-4 levels and incident hip fractures overall (p ≥ 0.24) or in gender stratified analyses (p ≥ 0.39).

CONCLUSION

Plasma DPP-4 activity, within the endogenous physiological range, was significantly associated with race, but not with BMD, body composition, or incident hip fractures in elderly community-dwelling subjects.

Dipeptidyl peptidase-4 inhibition in patients with type 2 diabetes treated with saxagliptin, sitagliptin, or vildagliptin

INTRODUCTION

Saxagliptin, sitagliptin, and vildagliptin are dipeptidyl peptidase-4 (DPP-4) inhibitors widely approved for use in patients with type 2 diabetes. Using a crossover design, the present study compared trough levels of DPP-4 inhibition provided by these agents in a single cohort of patients with type 2 diabetes.

METHODS

This was a randomized, placebo-controlled, open-label, five-period crossover study. Eligible patients were 18-65 years of age, either treatment-naïve or off prior antihyperglycemic agent therapy for at least 6 or 12 weeks (depending on the prior therapy), and had glycated hemoglobin (HbA1C) ≥6.5% and ≤10.0%. In separate study periods, patients received 5 mg saxagliptin q.d. (saxa-5), 100 mg sitagliptin q.d. (sita-100), 50 mg vildagliptin q.d. (vilda-50-q.d.), 50 mg vildagliptin b.i.d. (vilda-50-b.i.d.), or placebo for 5 days. The primary endpoint was trough %DPP-4 inhibition, derived by comparing DPP-4 activity 24 h after the Day-5 morning dose with predose activity in the same period and analyzed using a linear mixed-effects model with fixed-effects terms for treatment and period.

RESULTS

Mean (range) baseline HbA1C was 7.4% (6.4-9.0%; N = 22). Least-squares (LS) mean trough %DPP-4 inhibition was 73.5%, 91.7%, 28.9%, 90.6%, and 3.5% after saxa-5, sita-100, vilda-50-q.d., vilda-50-b.i.d., and placebo, respectively. In patients treated with sita-100, the LS-mean difference in trough %DPP-4 inhibition was 18.2% greater than with saxa-5 (p < 0.001), 62.9% greater than with vilda-50-q.d. (p < 0.001), 1.1% greater than with vilda-50-b.i.d. (p = 0.128), and 87.8% greater than with placebo (p < 0.001). Mean %DPP-4 inhibition was nearly maximal at 12 h postdose regardless of active treatment. Thus, these between-group comparisons at trough primarily reflected differences in duration of action. Adverse events reported during the study were transient and mild or moderate in intensity.

CONCLUSION

Once daily treatment with sitagliptin provided trough DPP-4 inhibition significantly greater than saxagliptin or vildagliptin administered once daily, and similar to that provided by vildagliptin administered twice daily.

Safety and efficacy of sitagliptin-metformin in fixed combination for the treatment of type 2 diabetes mellitus

The biguanide, metformin, is considered first-line treatment for type 2 diabetes. Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor acts through the incretin pathway and has a glucose dependent mode of action. The complementary hypoglycemic properties of these drugs make fixed dose combination treatment an attractive prospect. Evidence from recent clinical trials suggests a beneficial effect of the combination on efficacy, demonstrated by significant improvement of hemoglobin A1c (HbA1c), fasting and postprandial glucose levels. The fixed dose combination is likely to have greater patient tolerability compared with monotherapy with either agent because of low rates of hypoglycemia, weight neutrality, and lower rates of side effects. High acquisition cost and paucity of long-term safety data are, however, potential barriers to their wider use. An overview of the pharmacology and clinical outcomes from recent trials of the metformin-sitagliptin combination and how the combination could fit into the type 2 diabetes treatment algorithm is presented in this review.

What are the preferred strategies for control of glycaemic variability in patients with type 2 diabetes mellitus?

The aim of therapy in type 2 diabetes in terms of blood glucose control is to reduce to target levels HbA1c and to reduce glycaemic variability in order to avoid both hypoglycaemia and wide excursions of postprandial glucose. The first approach to reduce glycaemic variability should consider a dietary and behavioural approach aiming to limit the glycaemic index and the glycaemic load of food and the prescription and implementation of a physical activity plan appropriate for the subject. From the pharmacological point of view, the diabetes specialist has now a much richer therapeutic armamentarium. The therapeutic algorithms can help the physician to choose the most appropriate drug. The traditional approach involves: i) metformin, acting mainly on fasting blood glucose; ii) sulphonylureas, that have shown a number of drawbacks, including the high risk of hypoglycemia; iii) pioglitazone, with a substantial effect on fasting and postprandial glucose and a low risk of hypoglycaemia; iv) insulin, that can be utilized with the basal or prandial approach. The new drugs belonging to the class of dipeptidyl peptidase-4 inhibitors have shown the reduction of postprandial glucose, a neutral effect on weight increase, a good safety profile and preliminary positive cardiovascular effects. When excess weight prevails, the glucagon-like peptide-1 agonists may be the preferred choice for their effect on weight reduction, reduction of hyperinsulinism and glycaemic variability.

Tolerability of dipeptidyl peptidase-4 inhibitors: a review

BACKGROUND

Oral glucose-lowering agents are used to treat patients with type 2 diabetes mellitus (T2DM). Most patients require multiple agents to maintain glycemic targets. Dipeptidyl peptidase-4 (DPP-4) inhibitors are administered as monotherapy and in combination therapy for the treatment of T2DM.

OBJECTIVE

The aim of this article was to provide a thorough review of published tolerability data on 5 DPP-4 inhibitors.

METHODS

PubMed and Web of Science were searched for English-language clinical trials published from January 2000 to June 2001, using the following key words: dipeptidyl peptidase-4 inhibitor, vildagliptin, alogliptin, sitagliptin, saxagliptin, linagliptin, safety, tolerability, efficacy, effect, AE, and adverse effect. Studies were considered for inclusion if they were randomized, double-blind trials performed in patients ≥18 years of age with T2DM and with a hemoglobin A(1c) of ≥6.5%; included ≥1 arm that received monotherapy with DPP-4; and reported adverse events (AEs). Studies in patients with a history of type 1 or secondary forms of diabetes, significant diabetic complications or cardiovascular disease within the 6 months before the start of the study, hepatic disease or abnormalities, and/or renal abnormalities were excluded.

RESULTS

A total of 45 clinical trials, 5 pharmacokinetic studies, and 28 meta-analyses or reviews were included. The duration of studies ranged from 7 days to 104 weeks. The most commonly reported AEs were nasopharyngitis, upper respiratory infections, all-cause infections, headache, gastrointestinal symptoms, and musculoskeletal pain. Based on the findings from the studies, the DPP-4 inhibitors had minimal impact on weight and were not associated with an increased risk for hypoglycemia relative to placebo. Rates of nasopharyngitis were higher with the DDP-4 inhibitors than with placebo. Pancreatitis was reported at lower rates with the DPP-4 inhibitors compared with other oral antihyperglycemic agents. Cardiovascular events were limited, and postmarketing studies are ongoing.

CONCLUSIONS

The tolerability of DPP-4 inhibitors is supported by published clinical trials. The rates of weight gain, gastrointestinal AEs, and hypoglycemia were minimal with the DPP-4 inhibitors studied.

Evaluation of pharmacokinetic parameters and dipeptidyl peptidase-4 inhibition following single doses of sitagliptin in healthy, young Japanese males

AIMS

Sitagliptin is a selective inhibitor of dipeptidyl peptidase-4 (DPP-4) used to treat type 2 diabetes. The present aim was to evaluate pharmacokinetic (PK), pharmacodynamic (PD) and safety characteristics of sitagliptin following single doses in healthy, young Japanese males.

METHODS

In this alternating two-panel, randomized, controlled double-blind study, six healthy Japanese male subjects (aged 20-46 years) in each panel received single oral doses of 5-400mg sitagliptin and two received placebo. Plasma and urine drug concentrations were measured from 0-48h post dose and plasma DPP-4 inhibition from 0-24h post dose. The results were compared with historical data from young, healthy non-Japanese males.

RESULTS

Plasma concentrations of sitagliptin increased approximately in proportion to dose; maximum concentrations occurred 2-6h post-dose. The mean apparent terminal half-life for plasma sitagliptin was 9-14h, with the half-life slightly decreasing as the dose increased. The mean dose fraction excreted unchanged in the urine was 0.73-1.00. Ingestion of a traditional Japanese breakfast prior to dosing had only a minor effect on PK parameters. After correction for dilution and competition effects during assay, doses of sitagliptin ≥50mg resulted in weighted average DPP-4 inhibition from 0-24h post-dose >94% (without correction, >78%). No clinically meaningful differences in PK and DPP-4 inhibition parameters were found between Japanese and non-Japanese subjects. Sitagliptin was generally well tolerated and there were no serious adverse experiences or episodes of hypoglycaemia.

CONCLUSIONS

The PK and PD findings from this study are consistent with once daily dosing of sitagliptin in Japanese patients with type 2 diabetes.

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.

Use of DPP-4 inhibitors in type 2 diabetes: focus on sitagliptin

Inhibition of dipeptidyl peptidase-4 (DPP-4) prevents the inactivation of glucagonlike peptide-1 (GLP-1). This increases circulating levels of active GLP-1, stimulates insulin secretion and inhibits glucagon secretion, which results in lowering of glucose levels and improvement of the glycemic control in patients with type 2 diabetes. This review summarizes experiences with DPP-4 inhibition in the treatment of type 2 diabetes, with a focus on sitagliptin. Sitagliptin has in several clinical studies been shown to improve metabolic control in type 2 diabetes, both when used as monotherapy and when used in combination with metformin, sulfonylurea, thiazolidinediones or insulin. The reduction in HbA(1c) is ≈ 0.6% to 1.0% from baseline levels of 7.5% to 8.7% over 6 to 12 months therapy. Sitagliptin has a favorable safety profile, is highly tolerable, and there is a minimal risk of hypoglycemia. Furthermore, sitagliptin is body weight neutral or induces a slight body weight reduction. Sitagliptin may be used in the early stages of type 2 diabetes in combination with metformin or other treatments in subjects with inadequate glycemic control on these treatments alone. Sitagliptin may also be used in monotherapy and, finally, sitagliptin may be used in combination with insulin in more advanced stages of the disease.