Pharmacotherapeutic group: Drugs used in diabetes, combinations of oral blood glucose lowering drugs, ATC code: A10BD11
Jentadueto combines two antihyperglycaemic medicinal products with complementary mechanisms of action to improve glycaemic control in patients with type 2 diabetes: linagliptin, a dipeptidyl peptidase 4 (DPP-4) inhibitor, and metformin hydrochloride, a member of the biguanide class.
Linagliptin
Mechanism of action
Linagliptin is an inhibitor of the enzyme DPP-4 (Dipeptidyl peptidase 4) an enzyme which is involved in the inactivation of the incretin hormones GLP-1 and GIP (glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide). These hormones are rapidly degraded by the enzyme DPP-4. Both incretin hormones are involved in the physiological regulation of glucose homeostasis. Incretins are secreted at a low basal level throughout the day and levels rise immediately after meal intake. GLP-1 and GIP increase insulin biosynthesis and secretion from pancreatic beta cells in the presence of normal and elevated blood glucose levels. Furthermore GLP-1 also reduces glucagon secretion from pancreatic alpha cells, resulting in a reduction in hepatic glucose output. Linagliptin binds very effectively to DPP-4 in a reversible manner and thus leads to a sustained increase and a prolongation of active incretin levels. Linagliptin glucose-dependently increases insulin secretion and lowers glucagon secretion thus resulting in an overall improvement in the glucose homeostasis. Linagliptin binds selectively to DPP-4 and exhibits a > 10 000 fold selectivity versus DPP-8 or DPP-9 activity in vitro.
Metformin
Mechanism of action
Metformin hydrochloride is a biguanide with antihyperglycaemic effects, lowering both basal and postprandial plasma glucose. It does not stimulate insulin secretion and therefore does not produce hypoglycaemia.
Metformin hydrochloride may act via 3 mechanisms:
(1) reduction of hepatic glucose production by inhibiting gluconeogenesis and glycogenolysis,
(2) in muscle, by increasing insulin sensitivity, improving peripheral glucose uptake and utilisation,
(3) and delay of intestinal glucose absorption.
Metformin hydrochloride stimulates intracellular glycogen synthesis by acting on glycogen synthase.
Metformin hydrochloride increases the transport capacity of all types of membrane glucose transporters (GLUTs) known to date.
In humans, independently of its action on glycaemia, metformin hydrochloride has favourable effects on lipid metabolism. This has been shown at therapeutic doses in controlled, medium-term or long-term clinical studies: metformin hydrochloride reduces total cholesterol, LDL cholesterol and triglyceride levels.
Clinical efficacy and safety
Linagliptin as add-on to metformin therapy
The efficacy and safety of linagliptin in combination with metformin in patients with insufficient glycaemic control on metformin monotherapy was evaluated in a double-blind placebo-controlled study of 24 weeks duration. Linagliptin added to metformin provided significant improvements in HbA1c, (-0.64% change compared to placebo), from a mean baseline HbA1c of 8%. Linagliptin also showed significant improvements in fasting plasma glucose (FPG) by -21.1 mg/dl and 2-hour post-prandial glucose (PPG) by -67.1 mg/dl compared to placebo, as well as a greater portion of patients achieving a target HbA1c of < 7.0% (28.3% on linagliptin versus 11.4% on placebo). The observed incidence of hypoglycaemia in patients treated with linagliptin was similar to placebo. Body weight did not differ significantly between the groups.
In a 24-week placebo-controlled factorial study of initial therapy, linagliptin 2.5 mg twice daily in combination with metformin (500 mg or 1 000 mg twice daily) provided significant improvements in glycaemic parameters compared with either monotherapy as summarised in Table 3 (mean baseline HbA1c 8.65%).
Table 3: Glycaemic parameters at final visit (24-week study) for linagliptin and metformin, alone and in combination in patients with type 2 diabetes mellitus inadequately controlled on diet and exercise
| | Placebo | Linagliptin 5 mg Once Daily1 | Metformin HCl 500 mg Twice Daily | Linagliptin 2.5 mg Twice Daily1 + Metformin HCl 500 mg Twice Daily | Metformin HCl 1 000 mg Twice Daily | Linagliptin 2.5 mg Twice Daily1 + Metformin HCl 1 000 mg Twice Daily |
| HbA1c (%) | | | | | | |
| Number of patients | n = 65 | n = 135 | n = 141 | n = 137 | n = 138 | n = 140 |
| Baseline (mean) | 8.7 | 8.7 | 8.7 | 8.7 | 8.5 | 8.7 |
| Change from baseline (adjusted mean) | 0.1 | -0.5 | -0.6 | -1.2 | -1.1 | -1.6 |
| Difference from placebo (adjusted mean) (95% CI) | -- | -0.6 (-0.9, -0.3) | -0.8 (-1.0, -0.5) | -1.3 (-1.6, -1.1) | -1.2 (-1.5, -0.9) | -1.7 (-2.0, -1.4) |
| Patients (n, %) achieving HbA1c < 7% | 7 (10.8) | 14 (10.4) | 27 (19.1) | 42 (30.7) | 43 (31.2) | 76 (54.3) |
| Patients (%) receiving rescue treatment | 29.2 | 11.1 | 13.5 | 7.3 | 8.0 | 4.3 |
| FPG (mg/dL) | | | | | | |
| Number of patients | n = 61 | n = 134 | n = 136 | n = 135 | n = 132 | n = 136 |
| Baseline (mean) | 203 | 195 | 191 | 199 | 191 | 196 |
| Change from baseline (adjusted mean) | 10 | -9 | -16 | -33 | -32 | -49 |
| Difference from placebo (adjusted mean) (95% CI) | -- | -19 (-31, -6) | -26 (-38, -14) | -43 (-56, -31) | -42 (-55, -30) | -60 (-72, -47) |
1 Total daily dose of linagliptin is equal to 5 mg
Mean reductions from baseline in HbA1c were generally greater for patients with higher baseline HbA1c values. Effects on plasma lipids were generally neutral. The decrease in body weight with the combination of linagliptin and metformin was similar to that observed for metformin alone or placebo; there was no change in weight from baseline for patients on linagliptin alone. The incidence of hypoglycaemia was similar across treatment groups (placebo 1.4%, linagliptin 5 mg 0%, metformin 2.1%, and linagliptin 2.5 mg plus metformin twice daily 1.4%).
The efficacy and safety of linagliptin 2.5 mg twice daily versus 5 mg once daily in combination with metformin in patients with insufficient glycaemic control on metformin monotherapy was evaluated in a double-blind placebo-controlled study of 12 weeks duration. Linagliptin 5 mg once daily and 2.5 mg twice daily provided comparable (CI: -0.07; 0.19) significant HbA1c reductions of -0.80% (from baseline 7.98%), and -0.74% (from baseline 7.96%) compared to placebo. The observed incidence of hypoglycaemia in patients treated with linagliptin was similar to placebo. Body weight did not differ significantly between the groups.
Linagliptin as add-on to a combination of metformin and sulphonylurea therapy
A placebo-controlled study of 24 weeks in duration was conducted to evaluate the efficacy and safety of linagliptin 5 mg to placebo, in patients not sufficiently treated with a combination with metformin and a sulphonylurea. Linagliptin provided significant improvements in HbA1c (-0.62% change compared to placebo), from a mean baseline HbA1c of 8.14%. Linagliptin also showed significant improvements in patients achieving a target HbA1c of < 7.0% (31.2% on linagliptin versus 9.2% on placebo), and also for fasting plasma glucose (FPG) with -12.7 mg/dl reduction compared to placebo. Body weight did not differ significantly between the groups.
Linagliptin as add on to a combination of metformin and empagliflozin therapy
In patients inadequately controlled with metformin and empagliflozin (10 mg (n= 247) or 25 mg (n = 217)), 24-weeks treatment with add-on therapy of linagliptin 5 mg provided adjusted mean HbA1c reductions from baseline by -0.53% (significant difference to add-on placebo -0.32% (95% CI -0.52, -0.13) and -0.58% (significant difference to add-on placebo -0.47% (95% CI -0.66; -0.28), respectively. A statistically significant greater proportion of patients with a baseline HbA1c ≥ 7.0% and treated with linagliptin 5 mg achieved a target HbA1c of < 7% compared to placebo.
Linagliptin in combination with metformin and insulin
A 24-week placebo-controlled study was conducted to evaluate the efficacy and safety of linagliptin (5 mg once daily) added to insulin with or without metformin. 83% of patients were taking metformin in combination with insulin in this trial. Linagliptin in combination with metformin plus insulin provided significant improvements in HbA1c in this subgroup with -0.68% (CI: -0.78; -0,57) adjusted mean change from baseline (mean baseline HbA1c 8.28%) compared to placebo in combination with metformin plus insulin. There was no meaningful change from baseline in body weight in either group.
Linagliptin 24 month data, as add-on to metformin in comparison with glimepiride
In a study comparing the efficacy and safety of the addition of linagliptin 5 mg or glimepiride (mean dose 3 mg) in patients with inadequate glycaemic control on metformin monotherapy, mean reductions in HbA1c were -0.16% with linagliptin (mean baseline HbA1c 7.69%) and -0.36% with glimepiride (mean baseline HbA1c 7.69%.) with a mean treatment difference of 0.20% (97.5% CI: 0.09, 0.299). The incidence of hypoglycaemia in the linagliptin group (7.5%) was significantly lower than that in the glimepiride group (36.1%). Patients treated with linagliptin exhibited a significant mean decrease from baseline in body weight compared to a significant weight gain in patients administered glimepiride (-1.39 versus +1.29 kg).
Linagliptin as add-on therapy in elderly (age ≥ 70 years) with type 2 diabetes
The efficacy and safety of linagliptin in elderly (age ≥ 70 years) with type 2 diabetes was evaluated in a double-blind study of 24 weeks duration. Patients received metformin and/or sulphonylurea and/or insulin as background therapy. Doses of background anti-diabetic therapy were kept stable during the first 12 weeks, after which adjustments were permitted. Linagliptin provided significant improvements in HbA1c (-0.64% change compared to placebo after 24 weeks), from a mean baseline HbA1c of 7.8%. Linagliptin also showed significant improvements in fasting plasma glucose (FPG) compared to placebo. Body weight did not differ significantly between the groups.
In a pooled analysis of elderly (age ≥ 70 years) patients with type 2 diabetes (n = 183) who were taking both metformin and basal insulin as background therapy, linagliptin in combination with metformin plus insulin provided significant improvements in HbA1c parameters with -0.81% (CI: -1.01; -0.61) adjusted mean change from baseline (mean baseline HbA1c 8.13%) compared to placebo in combination with metformin plus insulin.
Linagliptin cardiovascular and renal safety study (CARMELINA)
CARMELINA was a randomized study in 6 979 patients with type 2 diabetes with increased CV risk evidenced by a history of established macrovascular or renal disease who were treated with linagliptin 5 mg (3 494) or placebo (3 485) added to standard of care targeting regional standards for HbA1c, CV risk factors and renal disease. The study population included 1 211 (17.4%) patients ≥ 75 years of age and 4 348 (62.3%) patients with renal impairment. Approximately 19% of the population had eGFR ≥ 45 to < 60 mL/min/1.73 m2, 28% of the population had eGFR ≥ 30 to < 45 mL/min/1.73 m2) and 15% had eGFR < 30 mL/min/1.73 m2. The mean HbA1c at baseline was 8.0%.
The study was designed to demonstrate non-inferiority for the primary cardiovascular endpoint which was a composite of the first occurrence of cardiovascular death or a non-fatal myocardial infarction (MI) or a non-fatal stroke (3P-MACE). The renal composite endpoint was defined as renal death or sustained end stage renal disease or sustained decrease of 40% or more in eGFR.
After a median follow up of 2.2 years, linagliptin, when added to standard of care, did not increase the risk of major adverse cardiovascular events or renal outcome events. There was no increased risk in hospitalization for heart failure which was an additional adjudicated endpoint observed compared to standard of care without linagliptin in patients with type 2 diabetes (table 4).
Table 4: Cardiovascular and renal outcomes by treatment group in the CARMELINA study
| | Linagliptin 5 mg | Placebo | Hazard Ratio |
| Number of Subjects (%) | Incidence Rate per 1 000 PY* | Number of Subjects (%) | Incidence Rate per 1 000 PY* | (95% CI) |
| Number of patients | 3 494 | | 3 485 | | |
| Primary CV composite (Cardiovascular death, non-fatal MI, non-fatal stroke) | 434 (12.4) | 57.7 | 420 (12.1) | 56.3 | 1.02 (0.89, 1.17)** |
| Secondary renal composite (renal death, ESRD, 40% sustained decrease in eGFR) | 327 (9.4) | 48.9 | 306 (8.8) | 46.6 | 1.04 (0.89, 1.22) |
| All-cause mortality | 367 (10.5) | 46.9 | 373 (10.7) | 48.0 | 0.98 (0.84, 1.13) |
| CV death | 255 (7.3) | 32.6 | 264 (7.6) | 34 | 0.96 (0.81, 1.14) |
| Hospitalization for heart failure | 209 (6.0) | 27.7 | 226 (6.5) | 30.4 | 0.90 (0.74, 1.08) |
* PY=patient years
** Test on non-inferiority to demonstrate that the upper bound of the 95% CI for the hazard ratio is less than 1.3
In analyses for albuminuria progression (change from normoalbuminuria to micro- or macroalbuminuria, or from microalbuminuria to macroalbuminuria) the estimated hazard ratio was 0.86 (95% CI 0.78, 0.95) for linagliptin versus placebo.
Linagliptin cardiovascular safety study (CAROLINA)
CAROLINA was a randomized study in 6 033 patients with early type 2 diabetes and increased CV risk or established complications who were treated with linagliptin 5 mg (3 023) or glimepiride 1-4 mg (3 010) added to standard of care (including background therapy with metformin in 83% of patients) targeting regional standards for HbA1c and CV risk factors. The mean age for study population was 64 years and included 2 030 (34%) patients ≥ 70 years of age. The study population included 2 089 (35%) patients with cardiovascular disease and 1 130 (19%) patients with renal impairment with an eGFR < 60 mL/min/1.73 m2 at baseline. The mean HbA1c at baseline was 7.15%.
The study was designed to demonstrate non-inferiority for the primary cardiovascular endpoint which was a composite of the first occurrence of cardiovascular death or a non-fatal myocardial infarction (MI) or a non-fatal stroke (3P-MACE).
After a median follow up of 6.25 years, linagliptin, when added to standard of care, did not increase the risk of major adverse cardiovascular events (table 5) as compared to glimepiride. Results were consistent for patients treated with or without metformin.
Table 5: Major adverse cardiovascular events (MACE) and mortality by treatment group in the CAROLINA study
| | Linagliptin 5 mg | Glimepiride (1-4 mg) | Hazard Ratio |
| Number of Subjects (%) | Incidence Rate per 1 000 PY* | Number of Subjects (%) | Incidence Rate per 1 000 PY* | (95% CI) |
| Number of patients | 3 023 | 3 010 | |
| Primary CV composite (Cardiovascular death, non-fatal MI, non-fatal stroke) | 356 (11.8) | 20.7 | 362 (12.0) | 21.2 | 0.98 (0.84, 1.14)** |
| All-cause mortality | 308 (10.2) | 16.8 | 336 (11.2) | 18.4 | 0.91 (0.78,1.06) |
| CV death | 169 (5.6) | 9.2 | 168 (5.6) | 9.2 | 1.00 (0.81, 1.24) |
| Hospitalization for heart failure (HHF) | 112 (3.7) | 6.4 | 92 (3.1) | 5.3 | 1.21 (0.92, 1.59) |
* PY=patient years
** Test on non-inferiority to demonstrate that the upper bound of the 95% CI for the hazard ratio is less than 1.3
For the entire treatment period (median time on treatment 5.9 years) the rate of patients with moderate or severe hypoglycaemia was 6.5% on linagliptin versus 30.9% on glimepiride, severe hypoglycaemia occurred in 0.3% of patients on linagliptin versus 2.2% on glimepiride.
Metformin
The prospective randomised (UKPDS) study has established the long-term benefit of intensive blood glucose control in type 2 diabetes. Analysis of the results for overweight patients treated with metformin after failure of diet alone showed:
• a significant reduction of the absolute risk of any diabetes-related complication in the metformin group (29.8 events/1 000 patient-years) versus diet alone (43.3 events/1 000 patient-years), p = 0.0023, and versus the combined sulphonylurea and insulin monotherapy groups (40.1 events/1 000 patient-years), p = 0.0034,
• a significant reduction of the absolute risk of any diabetes-related mortality: metformin 7.5 events/1 000 patient-years, diet alone 12.7 events/1 000 patient-years, p = 0.017,
• a significant reduction of the absolute risk of overall mortality: metformin 13.5 events/1 000 patient-years versus diet alone 20.6 events/1 000 patient-years, (p = 0.011), and versus the combined sulphonylurea and insulin monotherapy groups 18.9 events/1 000 patient-years (p = 0.021),
• a significant reduction in the absolute risk of myocardial infarction: metformin 11 events/1 000 patient-years, diet alone 18 events/1 000 patient-years, (p = 0.01).
Paediatric population
The clinical efficacy and safety of empagliflozin 10 mg with potential dose-increase to 25 mg or linagliptin 5 mg once daily has been studied in children and adolescents from 10 to 17 years of age with T2DM in a double-blind, randomised, placebo-controlled, parallel group study (DINAMO) over 26 weeks, with a double-blind active treatment safety extension period up to 52 weeks. 91% of patients in the study were on background therapy with metformin as adjunct to diet and exercise.
At baseline, the mean HbA1c was 8.03%. Treatment with linagliptin 5 mg did not provide significant improvement in HbA1c. The treatment difference of adjusted mean change in HbA1c after 26 weeks between linagliptin and placebo was -0.34% (95% CI -0.99, 0.30; p=0.2935). The adjusted mean change in HbA1c from baseline was 0.33% in patients treated with linagliptin and 0.68% in patients treated with placebo (see section 4.2).