Pharmacotherapeutic group: Drugs used in diabetes, combinations of oral blood glucose lowering drugs, ATC code: A10BD19
Mechanism of action
Glyxambi combines two antihyperglycaemic medicinal products with complementary mechanisms of action to improve glycaemic control in patients with type 2 diabetes: empagliflozin, a sodium-glucose co-transporter (SGLT2) inhibitor, and linagliptin, DPP-4 inhibitor.
Empagliflozin
Empagliflozin is a reversible, highly potent (IC50 of 1.3 nmol) and selective competitive inhibitor of SGLT2. Empagliflozin does not inhibit other glucose transporters important for glucose transport into peripheral tissues and is 5 000 times more selective for SGLT2 versus SGLT1, the major transporter responsible for glucose absorption in the gut.
SGLT2 is highly expressed in the kidney, whereas expression in other tissues is absent or very low. It is responsible, as the predominant transporter, for the reabsorption of glucose from the glomerular filtrate back into the circulation. In patients with type 2 diabetes and hyperglycaemia a higher amount of glucose is filtered and reabsorbed.
Empagliflozin improves glycaemic control in patients with type 2 diabetes mellitus by reducing renal glucose re-absorption. The amount of glucose removed by the kidney through this glucuretic mechanism is dependent upon the blood glucose concentration and GFR. Inhibition of SGLT2 in patients with type 2 diabetes mellitus and hyperglycaemia leads to excess glucose excretion in the urine. In addition, initiation of empagliflozin increases excretion of sodium resulting in osmotic diuresis and reduced intravascular volume.
In patients with type 2 diabetes, urinary glucose excretion increased immediately following the first dose of empagliflozin and was continuous over the 24-hour dosing interval. Increased urinary glucose excretion was maintained at the end of the 4-week treatment period, averaging approximately 78 g/day. Increased urinary glucose excretion resulted in an immediate reduction in plasma glucose levels in patients with type 2 diabetes.
Empagliflozin improves both fasting and post prandial plasma glucose levels. The mechanism of action of empagliflozin is independent of beta cell function and insulin pathway and this contributes to a low risk of hypoglycaemia. Improvement of surrogate markers of beta cell function including Homeostasis Model Assessment β (HOMA β) was noted. In addition, urinary glucose excretion triggers calorie loss, associated with body fat loss and body weight reduction. The glucosuria observed with empagliflozin is accompanied by diuresis which may contribute to sustained and moderate reduction of blood pressure. The glucosuria, natriuresis and osmotic diuresis observed with empagliflozin may contribute to the improvement in cardiovascular outcomes.
Linagliptin
Linagliptin is an inhibitor of DPP-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.
Clinical efficacy and safety
A total of 2 173 patients with type 2 diabetes mellitus and inadequate glycaemic control were treated in clinical trials to evaluate the safety and efficacy of Glyxambi; 1 005 patients were treated with Glyxambi 10 mg empagliflozin/5 mg linagliptin or 25 mg empagliflozin/5 mg linagliptin. In clinical trials, patients were treated for up to 24 or 52 weeks.
Glyxambi added to metformin
In a factorial design trial patients inadequately controlled on metformin were treated for 24-weeks with Glyxambi 10 mg/5 mg, Glyxambi 25 mg/5 mg, empagliflozin 10 mg, empagliflozin 25 mg or linagliptin 5 mg. The treatment with Glyxambi resulted in statistically significant improvements in HbA1c (see Table 3) and fasting plasma glucose (FPG) compared to linagliptin 5 mg and also compared to empagliflozin 10 mg or 25 mg. Glyxambi also provided statistically significant improvements in body weight compared to linagliptin 5 mg.
Table 3 Efficacy parameters in clinical trial comparing Glyxambi to individual active substances as add-on therapy in patients inadequately controlled on metformin
| | Glyxambi 25 mg/5 mg | Glyxambi 10 mg/5 mg | Empagliflozin 25 mg | Empagliflozin 10 mg | Linagliptin 5 mg |
| Primary endpoint: HbA1c ( %) – 24 weeks |
| Number of patients analysed | 134 | 135 | 140 | 137 | 128 |
| Baseline mean (SE) | 7.90 (0.07) | 7.95 (0.07) | 8.02 (0.07) | 8.00 (0.08) | 8.02 (0.08) |
| Change from baseline at week 241: - adjusted mean2 (SE) | -1.19 (0.06) | -1.08 (0.06) | -0.62 (0.06) | -0.66 (0.06) | -0.70 (0.06) |
| Comparison vs. empagliflozin1: - adjusted mean2 (SE) - 95.0 % CI - p-value | vs. 25 mg -0.58 (0.09) -0.75, -0.41 <0.0001 | vs. 10 mg -0.42 (0.09) -0.59, -0.25 <0.0001 | -- | -- | -- |
| Comparison vs. linagliptin 5 mg1: - adjusted mean2 (SE) - 95.0 % CI - p-value | -0.50 (0.09) -0.67, -0.32 <0.0001 | -0.39 (0.09) -0.56, -0.21 <0.0001 | -- | -- | -- |
| 1 Last observation (prior to glycaemic rescue ) carried forward (LOCF) 2 Mean adjusted for baseline value and stratification |
In a pre-specified subgroup of patients with baseline HbA1c greater or equal than 8.5%, the reduction from baseline in HbA1c at 24 weeks with Glyxambi 25 mg/5 mg was -1.8% (p<0.0001 versus linagliptin 5 mg, p<0.001 versus empagliflozin 25 mg) and with Glyxambi 10 mg/5 mg -1.6% (p<0.01 versus linagliptin 5 mg, n.s. versus empagliflozin 10 mg).
Overall, the effects on HbA1c reduction observed at 24 weeks were sustained at week 52.
Empagliflozin in patients inadequately controlled on metformin and linagliptin
In patients inadequately controlled on maximally tolerated doses of metformin, open label linagliptin 5 mg was added for 16 weeks. In patients inadequately controlled after this 16 week period, patients received double-blind treatment with either empagliflozin 10 mg, empagliflozin 25 mg or placebo for 24-weeks. After this double-blind period, treatment with both empagliflozin 10 mg and empagliflozin 25 mg provided statistically significant improvements in HbA1c, FPG and body weight compared to placebo; all patients continued treatment with metformin and linagliptin 5 mg during the trial. A statistically significant greater number of patients with a baseline HbA1c ≥7.0% treated with both doses of empagliflozin achieved a target HbA1c of <7% compared to placebo (see Table 4). After 24-weeks treatment with empagliflozin, both systolic and diastolic blood pressures were reduced, -2.6/-1.1 mmHg (n.s. versus placebo for SBP and DBP) for empagliflozin 25 mg and -1.3/-0.1 mmHg (n.s. versus placebo for SBP and DBP) for empagliflozin 10 mg.
After 24 weeks, rescue therapy was used in 4 (3.6%) patients treated with empagliflozin 25 mg and in 2 (1.8%) patients treated with empagliflozin 10 mg, compared to 13 (12.0%) patients treated with placebo (all patients on background metformin + linagliptin 5 mg).
Table 4 Efficacy parameters in the clinical trial comparing empagliflozin to placebo as add-on therapy in patients inadequately controlled on metformin and linagliptin 5 mg
| | Metformin + linagliptin 5 mg |
| Empagliflozin 10 mg1 | Empagliflozin 25 mg1 | Placebo2 |
| HbA1c ( %) - 24 weeks3 | | | |
| N | 109 | 110 | 106 |
| Baseline (mean) | 7.97 | 7.97 | 7.96 |
| Change from baseline (adjusted mean) | -0.65 | -0.56 | 0.14 |
| Comparison vs. placebo (adjusted mean) (95 % CI)2 | -0.79 (-1.02, -0.55) p<0.0001 | -0.70 (-0.93, -0.46) p<0.0001 | |
| Body Weight-24 weeks3 | | | |
| N | 109 | 110 | 106 |
| Baseline (mean) in kg | 88.4 | 84.4 | 82.3 |
| Change from baseline (adjusted mean) | -3.1 | -2.5 | -0.3 |
| Comparison vs. placebo (adjusted mean) (95 % CI)1 | -2.8 (-3.5, -2.1) p<0.0001 | -2.2 (-2.9, -1.5) p<0.0001 | |
| Patients ( %) achieving HbA1c <7 % with baseline HbA1c ≥7 % - 24 weeks4 | | | |
| N | 100 | 107 | 100 |
| Patients ( %) achieving A1C <7 % | 37.0 | 32.7 | 17.0 |
| Comparison vs. placebo (odds ratio) (95 % CI)5 | 4.0 (1.9, 8.7) | 2.9 (1.4, 6.1) | |
1 Patients randomised to the empagliflozin 10 mg or 25 mg groups were receiving Glyxambi 10 mg/5 mg or 25 mg/5 mg with background metformin
2 Patients randomised to the placebo group were receiving the placebo plus linagliptin 5 mg with background metformin
3 Mixed-effects models for repeated measurements (MMRM) on FAS (OC) includes baseline HbA1c, baseline eGFR (MDRD), geographical region, visit treatment,and treatment by visit interaction. For FPG, baseline FPG is also included. For weight, baseline weight is also included.
4 Not evaluated for statistical significance; not part of sequential testing procedure for the secondary endpoints
5 Logistic regression on FAS (NCF) includes baseline HbA1c, baseline eGFR (MDRD), geographical region, and treatment; based on patients with HbA1c of 7% and above at baseline
In a pre-specified subgroup of patients with baseline HbA1c greater or equal than 8.5% the reduction from baseline in HbA1c with empagliflozin 25 mg/linagliptin 5 mg was -1.3% at 24 weeks (p<0.0001 versus placebo and linagliptin 5 mg) and with empagliflozin 10 mg/linagliptin 5 mg -1.3% at 24 weeks (p<0.0001 versus placebo and linagliptin 5 mg).
Linagliptin 5 mg in patients inadequately controlled on metformin and empagliflozin 10 mg or empagliflozin 25 mg
In patients inadequately controlled on maximally tolerated doses of metformin, open label empagliflozin 10 mg or empagliflozin 25 mg was added for 16 weeks. In patients inadequately controlled after this 16 week period, patients received double-blind treatment with either linagliptin 5 mg or placebo for 24-weeks. After this double-blind period, treatment in both populations (metformin + empagliflozin 10 mg and metformin + empagliflozin 25 mg) linagliptin 5 mg provided statistically significant improvements in HbA1c compared to placebo; all patients continued treatment with metformin and empagliflozin during the trial. A statistically significant greater number of patients with a baseline HbA1c ≥7.0% and treated with linagliptin achieved a target HbA1c of <7% compared to placebo (see Table 5).
Table 5 Efficacy parameters in clinical trials comparing Glyxambi 10 mg/5 mg to empagliflozin 10 mg as well as Glyxambi 25 mg/5 mg to empagliflozin 25 mg as add-on therapy in patients inadequately controlled on empagliflozin 10 mg/25 mg and metformin
| | Metformin + empagliflozin 10 mg | Metformin + empagliflozin 25 mg |
| Linagliptin 5 mg | Placebo | Linagliptin 5 mg | Placebo |
| HbA1c ( %) – 24 weeks1 | | | | |
| N | 122 | 125 | 109 | 108 |
| Baseline (mean) | 8.04 | 8.03 | 7.82 | 7.88 |
| Change from baseline (adjusted mean) | -0.53 | -0.21 | -0.58 | -0.10 |
| Comparison vs. placebo (adjusted mean) (95 % CI) | -0.32 (-0.52, -0.13) p=0.0013 | | -0.47 (-0.66, -0.28) p<0.0001 | |
| Patients ( %) achieving HbA1c <7 % with baseline HbA1c ≥7 % – 24 weeks2 | | | | |
| N | 116 | 119 | 100 | 107 |
| Patients ( %) achieving HbA1c <7 % | 25.9 | 10.9 | 36.0 | 15.0 |
| Comparison vs. placebo (odds ratio) (95 % CI)3 | 3.965 (1.771, 8.876) p=0.0008 | | 4.429 (2.097, 9.353) p<0.0001 | |
Patients randomised to the linagliptin 5 mg group were receiving either fixed dose combination tablets Glyxambi 10 mg/5 mg plus metformin or fixed dose combination tablets Glyxambi 25 mg/5 mg plus metformin; patients randomised to the placebo group were receiving placebo plus empagliflozin 10 mg plus metformin or placebo plus empagliflozin 25 mg plus metformin
1 MMRM model on FAS (OC) includes baseline HbA1c, baseline eGFR (MDRD), geographical region, visit, treatment, and treatment by visit interaction. For FPG, baseline FPG is also included.
2 Not evaluated for statistical significance; not part of sequential testing procedure for the secondary endpoints
3 Logistic regression on FAS (NCF) includes baseline HbA1c, baseline eGFR (MDRD), geographical region, and treatment; based on patients with HbA1c of 7% and above at baseline
Cardiovascular safety
Empagliflozin cardiovascular outcome (EMPA-REG OUTCOME) trial
The double-blind, placebo-controlled EMPA-REG OUTCOME trial compared pooled doses of empagliflozin 10 mg and 25 mg with placebo as adjunct to standard care therapy in patients with type 2 diabetes and established cardiovascular disease. A total of 7 020 patients were treated (empagliflozin 10 mg: 2 345, empagliflozin 25 mg: 2 342, placebo: 2 333) and followed for a median of 3.1 years. The mean age was 63 years, the mean HbA1c was 8.1%, and 71.5% were male. At baseline, 74% of patients were being treated with metformin, 48% with insulin, and 43% with a sulfonylurea. About half of the patients (52.2%) had an eGFR of 60-90 ml/min/1.73 m2, 17.8% of 45-60 ml/min/1.73 m2 and 7.7% of 30-45 ml/min/1.73 m2.
At week 12, an adjusted mean (SE) improvement in HbA1c when compared to baseline of 0.11% (0.02) in the placebo group, 0.65% (0.02) and 0.71% (0.02) in the empagliflozin 10 and 25 mg groups was observed. After the first 12 weeks glycaemic control was optimized independent of investigative treatment. Therefore the effect was attenuated at week 94, with an adjusted mean (SE) improvement in HbA1c of 0.08% (0.02) in the placebo group, 0.50% (0.02) and 0.55% (0.02) in the empagliflozin 10 and 25 mg groups.
Empagliflozin was superior in preventing the primary combined endpoint of cardiovascular death, nonfatal myocardial infarction, or non-fatal stroke, as compared with placebo. The treatment effect was driven by a significant reduction in cardiovascular death with no significant change in non-fatal myocardial infarction, or non-fatal stroke. The reduction of cardiovascular death was comparable for empagliflozin 10 mg and 25 mg and confirmed by an improved overall survival (see Table 6). The effect of empagliflozin on the primary combined endpoint of CV death, non-fatal MI, or non-fatal stroke was largely independent of glycaemic control or renal function (eGFR) and generally consistent across eGFR categories down to an eGFR of 30 ml/min/1.73 m2 in the EMPA-REG OUTCOME study.
Table 6 Treatment effect for the primary composite endpoint, its components and mortalitya
| | Placebo | Empagliflozinb |
| N | 2333 | 4687 |
| Time to first event of CV death, non-fatal MI, or non-fatal stroke N (%) | 282 (12.1) | 490 (10.5) |
| Hazard ratio vs. placebo (95.02% CI)* | | 0.86 (0.74, 0.99) |
| p−value for superiority | | 0.0382 |
| CV Death N (%) | 137 (5.9) | 172 (3.7) |
| Hazard ratio vs. placebo (95% CI) | | 0.62 (0.49, 0.77) |
| p-value | | <0.0001 |
| Non-fatal MI N (%) | 121 (5.2) | 213 (4.5) |
| Hazard ratio vs. placebo (95% CI) | | 0.87 (0.70, 1.09) |
| p−value | | 0.2189 |
| Non-fatal stroke N (%) | 60 (2.6) | 150 (3.2) |
| Hazard ratio vs. placebo (95% CI) | | 1.24 (0.92, 1.67) |
| p−value | | 0.1638 |
| All-cause mortality N (%) | 194 (8.3) | 269 (5.7) |
| Hazard ratio vs. placebo (95% CI) | | 0.68 (0.57, 0.82) |
| p-value | | <0.0001 |
| Non-CV mortality N (%) | 57 (2.4) | 97 (2.1) |
| Hazard ratio vs. placebo (95% CI) | | 0.84 (0.60, 1.16) |
CV = cardiovascular, MI = myocardial infarction
a Treated set (TS), i.e. patients who had received at least one dose of trial drug
b Pooled doses of empagliflozin 10 mg and 25 mg
* Since data from the trial were included in an interim analysis, a two-sided 95.02% confidence interval applied which corresponds to a p-value of less than 0.0498 for significance.
The efficacy for preventing cardiovascular mortality has not been conclusively established in patients using empagliflozin concomitantly with DPP-4 inhibitors or in Black patients because the representation of these groups in the EMPA-REG OUTCOME trial was limited.
Heart failure requiring hospitalization
In the EMPA-REG OUTCOME trial, empagliflozin reduced the risk of heart failure requiring hospitalization compared with placebo (empagliflozin 2.7%; placebo 4.1%; HR 0.65, 95% CI 0.50, 0.85).
Nephropathy
In the EMPA-REG OUTCOME trial, for time to first nephropathy event, the HR was 0.61 (95% CI 0.53, 0.70) for empagliflozin (12.7%) vs placebo (18.8%).
In addition, empagliflozin showed a higher (HR 1.82, 95% CI 1.40, 2.37) occurrence of sustained normo- or micro-albuminuria (49.7%) in patients with baseline macro-albuminuria compared with placebo (28.8%).
Linagliptin cardiovascular and renal safety (CARMELINA) trial
The double-blind, placebo-controlled CARMELINA trial evaluated the cardiovascular and renal safety of linagliptin versus placebo as adjunct to standard care therapy in patients with type 2 diabetes and with increased CV risk evidenced by a history of established macrovascular or renal disease. A total of 6 979 patients were treated (linagliptin 5 mg: 3 494, placebo: 3 485) and followed for a median of 2.2 years. The trial population included 1 211 (17.4%) patients ≥ 75 years of age, the mean HbA1c was 8.0%, 63% were male. Approximately 19% of the population had an eGFR of 45-60 mL/min/1.73 m2, 28% of 30-45 mL/min/1.73 m2 and 15% of <30 mL/min/1.73 m².
Linagliptin did not increase the risk of the combined endpoint of CV death, non-fatal myocardial infarction or non-fatal stroke (MACE-3) [HR=1.02; (95% CI 0.89, 1.17); p=0.0002 for non-inferiority], or the risk of combined endpoint of renal death, ESRD, 40% or more sustained decrease in eGFR [HR=1.04; (95% CI 0.89, 1.22)]. 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. In addition, linagliptin did not increase the risk of hospitalization for heart failure [HR=0.90; (95% CI 0.74, 1.08)]. No increased risk of CV death or all-cause mortality was observed.
Safety data from this trial was in line with previous known safety profile of linagliptin.
Linagliptin cardiovascular safety (CAROLINA) trial
The double-blind parallel group CAROLINA trial evaluated the cardiovascular safety of linagliptin versus glimepiride as adjunct to standard care therapy in patients with type 2 diabetes and with increased CV risk. A total of 6 033 patients were treated (linagliptin 5 mg: 3 023, glimepiride 1 mg to 4 mg: 3 010) and followed for a median of 6.25 years. The mean age was 64 years, the mean HbA1c was 7.15%, and 60% were male. Approximately 19% of the population had an eGFR <60 mL/min/1.73 m2.
The trial 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). Linagliptin did not increase the risk of the combined endpoint of CV death, non-fatal myocardial infarction or non-fatal stroke (MACE-3) [Hazard Ratio (HR)=0.98; (95% CI 0.84, 1.14); p<0.0001 for non-inferiority], when added to standard of care in adult patients with type 2 diabetes with increased CV risk compared to glimepiride (see Table 7).
Table 7 Major adverse cardiovascular events (MACE) and mortality by treatment group in the CAROLINA trial
| | Linagliptin 5mg | Glimepiride (1-4mg) | Hazard ratio |
| Number of Subjects (%) | Incidence Rate per 1000 PY* | Number of Subjects (%) | Incidence Rate per 1000 PY* | (95% CI) |
| Number of patients | 3023 | 3010 | |
| 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
Paediatric population
Glyxambi is not recommended for use in children below 18 years of age as the safety and effectiveness have not been established (see section 4.2 for information on paediatric use).
The clinical efficacy and safety of empagliflozin 10 mg with possible dose-increase to 25 mg or linagliptin 5 mg once daily has been studied in children and adolescents from 10 to 17 years with type 2 diabetes mellitus 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. The mean HbA1c was 8.03% at baseline. The primary endpoint of the study was the change in HbA1c from baseline to the end of 26 weeks, regardless of glycaemic rescue or treatment discontinuation.
Empagliflozin
Empagliflozin was superior to placebo in reducing HbA1c. The treatment difference of adjusted mean change in HbA1c between empagliflozin and placebo was -0.84% (95% CI -1.50, -0.19; p=0.0116). The adjusted mean change in HbA1c from baseline in patients treated with empagliflozin (N=52) was -0.17% and 0.68% in patients treated with placebo (N=53).
Linagliptin
Treatment with linagliptin did not provide significant improvement in HbA1c. The treatment difference of adjusted mean change in HbA1c 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.