Clinical Pharmacology for Glyxambi
Mechanism Of Action
GLYXAMBI
GLYXAMBI contains: empagliflozin, a SGLT2 inhibitor, and linagliptin, a DPP-4 inhibitor.
Empagliflozin
Empagliflozin is an inhibitor of the SGLT2, the predominant transporter responsible for reabsorption of glucose from the glomerular filtrate back into the circulation. By inhibiting SGLT2, empagliflozin reduces renal reabsorption of filtered glucose and lowers the renal threshold for glucose, and thereby increases urinary glucose excretion.
Linagliptin
Linagliptin is an inhibitor of DPP-4, an enzyme that degrades the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Thus, linagliptin increases the concentrations of active incretin hormones, stimulating the release of insulin in a glucose-dependent manner and decreasing the levels of glucagon in the circulation. Both incretin hormones are involved in the physiological regulation of glucose homeostasis. Incretin hormones 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.
Pharmacodynamics
Empagliflozin
Urinary Glucose Excretion
In patients with type 2 diabetes mellitus, urinary glucose excretion increased immediately following a dose of empagliflozin and was maintained at the end of a 4-week treatment period averaging at approximately 64 grams per day with 10 mg empagliflozin and 78 grams per day with 25 mg empagliflozin once daily. Data from single oral doses of empagliflozin in healthy subjects indicate that, on average, the elevation in urinary glucose excretion approaches baseline by about 3 days for the 10 mg and 25 mg doses.
Urinary Volume
In a 5-day study, mean 24-hour urine volume increase from baseline was 341 mL on Day 1 and 135 mL on Day 5 of empagliflozin 25 mg once daily treatment.
Cardiac Electrophysiology
In a randomized, placebo-controlled, active-comparator, crossover study, 30 healthy subjects were administered a single oral dose of empagliflozin 25 mg, empagliflozin 200 mg (8 times the maximum recommended dose), moxifloxacin, and placebo. No increase in QTc was observed with either 25 mg or 200 mg empagliflozin.
Linagliptin
Linagliptin binds to DPP-4 in a reversible manner and increases the concentrations of incretin hormones. Linagliptin glucose-dependently increases insulin secretion and lowers glucagon secretion, thus resulting in a better regulation of the glucose homeostasis. Linagliptin binds selectively to DPP-4 and selectively inhibits DPP-4, but not DPP-8 or DPP-9 activity in vitro at concentrations approximating therapeutic exposures.
Cardiac Electrophysiology
In a randomized, placebo-controlled, active-comparator, 4-way crossover study, 36 healthy subjects were administered a single oral dose of linagliptin 5 mg, linagliptin 100 mg (20 times the recommended dose), moxifloxacin, and placebo. No increase in QTc was observed with either the recommended dose of 5 mg or the 100 mg dose. At the 100 mg dose, peak linagliptin plasma concentrations were approximately 38-fold higher than the peak concentrations following a 5-mg dose.
Pharmacokinetics
GLYXAMBI
Administration of the fixed-dose combination with food resulted in no change in overall exposure of empagliflozin or linagliptin; however, the peak exposure was decreased 39% and 32% for empagliflozin and linagliptin, respectively. These changes are not likely to be clinically significant.
Empagliflozin
The pharmacokinetics of empagliflozin has been characterized in healthy volunteers and patients with type 2 diabetes mellitus and no clinically relevant differences were noted between the two populations. The steadystate mean plasma AUC and Cmax were 1,870 nmol•h/L and 259 nmol/L, respectively, with 10 mg empagliflozin once daily treatment, and 4,740 nmol•h/L and 687 nmol/L, respectively, with 25 mg empagliflozin once daily treatment. Systemic exposure of empagliflozin increased in a dose-proportional manner in the therapeutic dose range. Empagliflozin does not appear to have time-dependent pharmacokinetic characteristics. Following oncedaily dosing, up to 22% accumulation, with respect to plasma AUC, was observed at steady-state.
Absorption
After oral administration, peak plasma concentrations of empagliflozin were reached at 1.5 hours post-dose. Administration of 25 mg empagliflozin after intake of a high-fat and high-calorie meal resulted in slightly lower exposure; AUC decreased by approximately 16% and Cmax decreased by approximately 37%, compared to fasted condition. The observed effect of food on empagliflozin pharmacokinetics was not considered clinically relevant and empagliflozin may be administered with or without food.
Distribution
The apparent steady-state volume of distribution was estimated to be 73.8 L based on a population pharmacokinetic analysis. Following administration of an oral [14C]-empagliflozin solution to healthy subjects, the red blood cell partitioning was approximately 36.8% and plasma protein binding was 86.2%.
Elimination
The apparent terminal elimination half-life of empagliflozin was estimated to be 12.4 h and apparent oral clearance was 10.6 L/h based on the population pharmacokinetic analysis.
Metabolism
No major metabolites of empagliflozin were detected in human plasma and the most abundant metabolites were three glucuronide conjugates (2-O-, 3-O-, and 6-O-glucuronide). Systemic exposure of each metabolite was less than 10% of total drug-related material. In vitro studies suggested that the primary route of metabolism of empagliflozin in humans is glucuronidation by the uridine 5'-diphospho-glucuronosyltransferases UGT2B7, UGT1A3, UGT1A8, and UGT1A9.
Excretion
Following administration of an oral [14C]-empagliflozin solution to healthy subjects, approximately 95.6% of the drug-related radioactivity was eliminated in feces (41.2%) or urine (54.4%). The majority of drug-related radioactivity recovered in feces was unchanged parent drug and approximately half of drug-related radioactivity excreted in urine was unchanged parent drug.
Linagliptin
Absorption
The absolute bioavailability of linagliptin is approximately 30%. High-fat meal reduced Cmax by 15% and increased AUC by 4%; this effect is not clinically relevant. Linagliptin may be administered with or without food.
Distribution
The mean apparent volume of distribution at steady-state following a single intravenous dose of linagliptin 5 mg to healthy subjects is approximately 1,110 L, indicating that linagliptin extensively distributes to the tissues. Plasma protein binding of linagliptin is concentration-dependent, decreasing from about 99% at 1 nmol/L to 75% to 89% at ≥30 nmol/L, reflecting saturation of binding to DPP-4 with increasing concentration of linagliptin. At high concentrations, where DPP-4 is fully saturated, 70% to 80% of linagliptin remains bound to plasma proteins and 20% to 30% is unbound in plasma. Plasma binding is not altered in patients with renal or hepatic impairment.
Elimination
Linagliptin has a terminal half-life of about 200 hours at steady-state, though the accumulation half-life is about 11 hours. Renal clearance at steady-state was approximately 70 mL/min.
Metabolism
Following oral administration, the majority (about 90%) of linagliptin is excreted unchanged, indicating that metabolism represents a minor elimination pathway. A small fraction of absorbed linagliptin is metabolized to a pharmacologically inactive metabolite, which shows a steady-state exposure of 13.3% relative to linagliptin.
Excretion
Following administration of an oral [14C]-linagliptin dose to healthy subjects, approximately 85% of the administered radioactivity was eliminated via the enterohepatic system (80%) or urine (5%) within 4 days of dosing.
Specific Populations
Effects Of Age, Body Mass Index, Gender, And Race
Empagliflozin
Age, body mass index (BMI), gender and race (Asians versus primarily Whites) do not have a clinically meaningful effect on pharmacokinetics of empagliflozin.
Linagliptin
Based on the population PK analysis, age, body mass index (BMI), gender and race do not have a clinically meaningful effect on pharmacokinetics of linagliptin [see Use In Specific Populations].
Patients With Renal Impairment
GLYXAMBI
Studies characterizing the pharmacokinetics of empagliflozin and linagliptin after administration of GLYXAMBI in renally impaired patients have not been performed.
Empagliflozin
In patients with mild (eGFR: 60 to less than 90 mL/min/1.73 m²), moderate (eGFR: 30 to less than 60 mL/min/1.73 m²), and severe (eGFR: less than 30 mL/min/1.73 m²) renal impairment and patients on dialysis due to kidney failure, AUC of empagliflozin increased by approximately 18%, 20%, 66%, and 48%, respectively, compared to subjects with normal renal function. Peak plasma levels of empagliflozin were similar in patients with moderate renal impairment and patients on dialysis due to kidney failure compared to subjects with normal renal function. Peak plasma levels of empagliflozin were roughly 20% higher in patients with mild and severe renal impairment as compared to subjects with normal renal function. Population pharmacokinetic analysis showed that the apparent oral clearance of empagliflozin decreased, with a decrease in eGFR leading to an increase in drug exposure. However, the fraction of empagliflozin that was excreted unchanged in urine, and urinary glucose excretion, declined with decrease in eGFR.
Linagliptin
An open-label pharmacokinetic study evaluated the pharmacokinetics of linagliptin 5 mg in male and female patients with varying degrees of chronic renal impairment. The study included 6 healthy subjects with normal renal function (creatinine clearance [CrCl] ≥80 mL/min), 6 patients with mild renal impairment (CrCl 50 to <80 mL/min), 6 patients with moderate renal impairment (CrCl 30 to <50 mL/min), 10 patients with type 2 diabetes mellitus and severe renal impairment (CrCl <30 mL/min), and 11 patients with type 2 diabetes mellitus and normal renal function. Creatinine clearance was measured by 24-hour urinary creatinine clearance measurements or estimated from serum creatinine based on the Cockcroft-Gault formula.
Under steady-state conditions, linagliptin exposure in patients with mild renal impairment was comparable to healthy subjects.
In patients with moderate renal impairment under steady-state conditions, mean exposure of linagliptin increased (AUCτ,ss by 71% and Cmax by 46%) compared with healthy subjects. This increase was not associated with a prolonged accumulation half-life, terminal half-life, or an increased accumulation factor. Renal excretion of linagliptin was below 5% of the administered dose and was not affected by decreased renal function. Patients with type 2 diabetes mellitus and severe renal impairment showed steady-state exposure approximately 40% higher than that of patients with type 2 diabetes mellitus and normal renal function (increase in AUCτ,ss by 42% and Cmax by 35%). For both type 2 diabetes mellitus groups, renal excretion was below 7% of the administered dose.
These findings were further supported by the results of population pharmacokinetic analyses.
Patients With Hepatic Impairment
GLYXAMBI
Studies characterizing the pharmacokinetics of empagliflozin and linagliptin after administration of GLYXAMBI in hepatically impaired patients have not been performed.
Empagliflozin
In patients with mild, moderate, and severe hepatic impairment according to the Child-Pugh classification, AUC of empagliflozin increased by approximately 23%, 47%, and 75% and Cmax increased by approximately 4%, 23%, and 48%, respectively, compared to subjects with normal hepatic function.
Linagliptin
In patients with mild hepatic impairment (Child-Pugh class A) steady-state exposure (AUCτ,ss) of linagliptin was approximately 25% lower and Cmax,ss was approximately 36% lower than in healthy subjects. In patients with moderate hepatic impairment (Child-Pugh class B), AUCss of linagliptin was about 14% lower and Cmax,ss was approximately 8% lower than in healthy subjects. Patients with severe hepatic impairment (Child- Pugh class C) had comparable exposure of linagliptin in terms of AUC0-24 and approximately 23% lower Cmax compared with healthy subjects. Reductions in the pharmacokinetic parameters seen in patients with hepatic impairment did not result in reductions in DPP-4 inhibition.
Drug Interaction Studies
Pharmacokinetic drug interaction studies with GLYXAMBI have not been performed; however, such studies have been conducted with the individual components of GLYXAMBI (empagliflozin and linagliptin).
Empagliflozin
In vitro Assessment Of Drug Interactions
Empagliflozin does not inhibit, inactivate, or induce CYP450 isoforms. In vitro data suggest that the primary route of metabolism of empagliflozin in humans is glucuronidation by the uridine 5'-diphosphoglucuronosyltransferases UGT1A3, UGT1A8, UGT1A9 and UGT2B7. Empagliflozin does not inhibit UGT1A1, UGT1A3, UGT1A8, UGT1A9, or UGT2B7. Therefore, no effect of empagliflozin is anticipated on concomitantly administered drugs that are substrates of the major CYP450 isoforms or UGT1A1, UGT1A3, UGT1A8, UGT1A9, or UGT2B7. The effect of UGT induction (e.g., induction by rifampicin or any other UGT enzyme inducer) on empagliflozin exposure has not been evaluated.
Empagliflozin is a substrate for P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), but it does not inhibit these efflux transporters at therapeutic doses. Based on in vitro studies, empagliflozin is considered unlikely to cause interactions with drugs that are P-gp substrates. Empagliflozin is a substrate of the human uptake transporters OAT3, OATP1B1, and OATP1B3, but not OAT1 and OCT2. Empagliflozin does not inhibit any of these human uptake transporters at clinically relevant plasma concentrations and, therefore, no effect of empagliflozin is anticipated on concomitantly administered drugs that are substrates of these uptake transporters.
In vivo Assessment Of Drug Interactions
Empagliflozin pharmacokinetics were similar with and without coadministration of metformin, glimepiride, pioglitazone, sitagliptin, linagliptin, warfarin, verapamil, ramipril, and simvastatin in healthy volunteers and with or without coadministration of hydrochlorothiazide and torsemide in patients with type 2 diabetes mellitus (see Figure 1). In subjects with normal renal function, coadministration of empagliflozin with probenecid resulted in a 30% decrease in the fraction of empagliflozin excreted in urine without any effect on 24-hour urinary glucose excretion. The relevance of this observation to patients with renal impairment is unknown.
Figure 1 : Effect of Various Medications on the Pharmacokinetics of Empagliflozin as Displayed as 90% Confidence Interval of Geometric Mean AUC and Cmax Ratios [reference lines indicate 100% (80% - 125%)]
aempagliflozin, 50 mg, once daily; bempagliflozin, 25 mg, single dose; cempagliflozin, 25 mg, once daily; dempagliflozin, 10 mg, single dose
Empagliflozin had no clinically relevant effect on the pharmacokinetics of metformin, glimepiride, pioglitazone, sitagliptin, linagliptin, warfarin, digoxin, ramipril, simvastatin, hydrochlorothiazide, torsemide, and oral contraceptives when coadministered in healthy volunteers (see Figure 2).
Figure 2 : Effect of Empagliflozin on the Pharmacokinetics of Various Medications as Displayed as 90% Confidence Interval of Geometric Mean AUC and Cmax Ratios [reference lines indicate 100% (80% - 125%)]
aempagliflozin, 50 mg, once daily; bempagliflozin, 25 mg, once daily; cempagliflozin, 25 mg, single dose; dadministered as
simvastatin; eadministered as warfarin racemic mixture; fadministered as Microgynon®; gadministered as ramipril
Linagliptin
In vitro Assessment Of Drug Interactions
Linagliptin is a weak to moderate inhibitor of CYP isozyme CYP3A4, but does not inhibit other CYP isozymes and is not an inducer of CYP isozymes, including CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 4A11. Linagliptin is a P-glycoprotein (P-gp) substrate, and inhibits P-gp mediated transport of digoxin at high concentrations. Based on these results and in vivo drug interaction studies, linagliptin is considered unlikely to cause interactions with other P-gp substrates at therapeutic concentrations.
In vivo Assessment Of Drug Interactions
Strong inducers of CYP3A4 or P-gp (e.g., rifampin) decrease exposure to linagliptin to subtherapeutic and likely ineffective concentrations [see DRUG INTERACTIONS]. In vivo studies indicated evidence of a low propensity for causing drug interactions with substrates of CYP3A4, CYP2C9, CYP2C8, P-gp and organic cationic transporter (OCT).
Table 4 describes the effect of coadministered drugs on systemic exposure of linagliptin.
Table 4 : Effect of Coadministered Drugs on Systemic Exposure of Linagliptin
| Coadministered Drug |
Dosing of Coadministered Druga |
Dosing of Linagliptina |
Geometric Mean Ratio (ratio with/without coadministered drug) No effect = 1.0 |
| AUCd |
Cmax |
| Metformin |
850 mg TID |
10 mg QD |
1.20 |
1.03 |
| Glyburide |
1.75 mgc |
5 mg QD |
1.02 |
1.01 |
| Pioglitazone |
45 mg QD |
10 mg QD |
1.13 |
1.07 |
| Ritonavir |
200 mg BID |
5 mgc |
2.01 |
2.96 |
| Rifampinb |
600 mg QD |
5 mg QD |
0.60 |
0.56 |
aMultiple dose (steady-state) unless otherwise noted
bFor information regarding clinical recommendations [see DRUG INTERACTIONS].
cSingle dose
dAUC = AUC(0 to 24 hours) for single dose treatments and AUC = AUC(TAU) for multiple-dose treatments
QD = once daily
BID = twice daily
TID = three times daily |
Table 5 describes the effect of linagliptin on systemic exposure of coadministered drugs.
Table 5 : Effect of Linagliptin on Systemic Exposure of Coadministered Drugs
| Coadministered Drug |
Dosing of Coadministered Druga |
Dosing of Linagliptina |
Geometric Mean Ratio (ratio with/without coadministered drug) No effect = 1.0 |
|
AUCc |
C max |
| Metformin |
850 mg TID |
10 mg QD |
metformin |
1.01 |
0.89 |
| Glyburide |
1.75 mgb |
5 mg QD |
glyburide |
0.86 |
0.86 |
| Pioglitazone |
45 mg QD |
10 mg QD |
pioglitazone |
0.94 |
0.86 |
| metabolite M-III |
0.98 |
0.96 |
| metabolite M-IV |
1.04 |
1.05 |
| Digoxin |
0.25 mg QD |
5 mg QD |
digoxin |
1.02 |
0.94 |
| Simvastatin |
40 mg QD |
10 mg QD |
simvastatin |
1.34 |
1.10 |
| simvastatin acid |
1.33 |
1.21 |
| Warfarin |
10 mgb |
5 mg QD |
R-warfarin |
0.99 |
1.00 |
| S-warfarin |
1.03 |
1.01 |
| INR |
0.93d |
1.04d |
| PT |
1.03d |
1.15d |
| Ethinylestradiol and levonorgestrel |
ethinylestradiol 0.03 mg and levonorgestrel 0.150 mg QD |
5 mg QD |
ethinylestradiol |
1.01 |
1.08 |
| levonorgestrel |
1.09 |
1.13 |
aMultiple dose (steady-state) unless otherwise noted
bSingle dose
cAUC = AUC(INF) for single dose treatments and AUC = AUC(TAU) for multiple dose treatments
dAUC=AUC(0-168) and Cmax = Emax for pharmacodynamic end points
INR = International Normalized Ratio
PT = Prothrombin Time
QD = once daily
TID = three times daily |
Clinical Studies
Glycemic Control Trials In Patients With Type 2 Diabetes Mellitus
Add-On Combination Therapy With Metformin
A total of 686 patients with type 2 diabetes mellitus participated in a double-blind, active-controlled trial to evaluate the efficacy of empagliflozin 10 mg or 25 mg in combination with linagliptin 5 mg compared to the individual components.
Patients with type 2 diabetes mellitus inadequately controlled on at least 1,500 mg of metformin per day entered a single-blind placebo run-in period for 2 weeks. At the end of the run-in period, patients who remained inadequately controlled and had an HbA1c between 7% and 10.5% were randomized 1:1:1:1:1 to one of 5 active-treatment arms of empagliflozin 10 mg or 25 mg, linagliptin 5 mg, or linagliptin 5 mg in combination with 10 mg or 25 mg empagliflozin as a fixed dosage combination tablet.
At Week 24, empagliflozin 10 mg or 25 mg used in combination with linagliptin 5 mg provided statistically significant improvement in HbA1c (p-value <0.0001) and FPG (p-value <0.001) compared to the individual components in patients who had been inadequately controlled on metformin (see Table 6, Figure 3). Treatment with GLYXAMBI 25 mg/5 mg or GLYXAMBI 10 mg/5 mg daily also resulted in a statistically significant reduction in body weight compared to linagliptin 5 mg (p-value <0.0001). There was no statistically significant difference compared to empagliflozin alone.
Table 6 : Glycemic Parameters at 24 Weeks in a Trial Comparing GLYXAMBI to the Individual Components as Add-on Therapy in Patients Inadequately Controlled on Metformin
|
GLYXAMBI 10 mg/5 mg |
GLYXAMBI 25 mg/5 mg |
Empagliflozin 10 mg |
Empagliflozin 25 mg |
Linagliptin 5 mg |
| HbA1c (%) |
| Number of patients |
n=135 |
n=133 |
n=137 |
n=139 |
n=128 |
| Baseline (mean) |
8.0 |
7.9 |
8.0 |
8.0 |
8.0 |
| Change from baseline (adjusted mean) |
-1.1 |
-1.2 |
-0.7 |
-0.6 |
-0.7 |
| Comparison vs empagliflozin 25 mg or 10 mg (adjusted mean) (95% CI)a |
-0.4
(-0.6, -0.2)d |
-0.6
(-0.7, -0.4)d |
-- |
-- |
-- |
| Comparison vs linagliptin 5 mg (adjusted mean) (95% CI)a |
-0.4
(-0.6, -0.2)d |
-0.5
(-0.7, -0.3)d |
-- |
-- |
-- |
| Patients [n (%)] achieving HbA1c <7%b |
74 (58) |
76 (62) |
35 (28) |
43 (33) |
43 (36) |
| FPG (mg/dL) |
| Number of patients |
n=133 |
n=131 |
n=136 |
n=137 |
n=125 |
| Baseline (mean) |
157 |
155 |
162 |
160 |
156 |
| Change from baseline (adjusted mean) |
-33 |
-36 |
-21 |
-21 |
-13 |
| Comparison vs empagliflozin 25 mg or 10 mg (adjusted mean) (95% CI)a |
-12 (-18, -5)d |
-15 (-22, -9)d |
-- |
-- |
-- |
| Comparison vs linagliptin 5 mg (adjusted mean) (95% CI)a |
-20 (-27, -13)d |
-23 (-29, -16)d |
-- |
-- |
-- |
| Body Weight |
| Number of patients |
n=135 |
n=134 |
n=137 |
n=140 |
n=128 |
| Baseline (mean) in kg |
87 |
85 |
86 |
88 |
85 |
| % change from baseline (adjusted mean) |
-3.1 |
-3.4 |
-3.0 |
-3.5 |
-0.7 |
| Comparison vs empagliflozin 25 mg or 10 mg (adjusted mean) (95% CI)c |
0.0 (-0.9, 0.8) |
0.1 (-0.8, 0.9) |
-- |
-- |
-- |
| Comparison vs linagliptin 5 mg (adjusted mean) (95% CI)c |
-2.4
(-3.3, -1.5)d |
-2.7
(-3.6, -1.8)d |
-- |
-- |
-- |
aFull analysis population (observed case) using MMRM. MMRM model included treatment, renal function, region, visit, visit by treatment interaction, and baseline HbA1c.
bPatients with HbA1c above 7% at baseline: GLYXAMBI 25 mg/5 mg, n=123; GLYXAMBI 10 mg/5 mg, n=128; empagliflozin 25 mg, n=132; empagliflozin 10 mg, n=125; linagliptin 5 mg, n=119. Non-completers were considered failures (NCF).
cFull analysis population using last observation carried forward. ANCOVA model included treatment, renal function, region, baseline weight, and baseline HbA1c.
dp<0.001 for FPG; p<0.0001 for HbA1c and body weight |
Figure 3 : Adjusted Mean HbA1c Change at Each Time Point (Completers) and at Week 24 (mITT population)
Empagliflozin Cardiovascular Outcomes In Patients With Type 2 Diabetes Mellitus And Atherosclerotic Cardiovascular Disease
EMPA-REG OUTCOME was a multicenter, multinational, randomized, double-blind parallel group trial that compared the risk of experiencing a major adverse cardiovascular event (MACE) between empagliflozin and placebo when these were added to and used concomitantly with standard of care treatments for diabetes mellitus and atherosclerotic CV disease. Concomitant antidiabetic medications were kept stable for the first 12 weeks of the trial. Thereafter, antidiabetic and atherosclerotic therapies could be adjusted, at the discretion of investigators, to ensure participants were treated according to the standard care for these diseases.
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. Approximately 72% of the trial population was White, 22% was Asian, and 5% was Black or African American. The mean age was 63 years and approximately 72% were male.
All patients in the trial had inadequately controlled type 2 diabetes mellitus at baseline (HbA1c greater than or equal to 7%). The mean HbA1c at baseline was 8.1% and 57% of participants had diabetes mellitus for more than 10 years. Approximately 31%, 22% and 20% reported a past history of neuropathy, retinopathy and nephropathy to investigators, respectively and the mean eGFR was 74 mL/min/1.73 m². At baseline, patients were treated with one (~30%) or more (~70%) antidiabetic medications including metformin (74%), insulin (48%), sulfonylurea (43%) and dipeptidyl peptidase-4 inhibitor (11%).
All patients had established atherosclerotic CV disease at baseline including one (82%) or more (18%) of the following: a documented history of coronary artery disease (76%), stroke (23%) or peripheral artery disease (21%). At baseline, the mean systolic blood pressure was 136 mmHg, the mean diastolic blood pressure was 76 mmHg, the mean LDL was 86 mg/dL, the mean HDL was 44 mg/dL, and the mean urinary albumin to creatinine ratio (UACR) was 175 mg/g. At baseline, approximately 81% of patients were treated with rennin angiotensin system inhibitors, 65% with beta-blockers, 43% with diuretics, 77% with statins, and 86% with antiplatelet agents (mostly aspirin).
The primary endpoint in EMPA-REG OUTCOME was the time to first occurrence of a Major Adverse Cardiac Event (MACE). A major adverse cardiac event was defined as occurrence of either a CV death or a non-fatal myocardial infarction (MI) or a non-fatal stroke. The statistical analysis plan had pre-specified that the 10 and 25 mg dosages would be combined. A Cox proportional hazards model was used to test for non-inferiority against the pre-specified risk margin of 1.3 for the hazard ratio of MACE and superiority on MACE if noninferiority was demonstrated. Type-1 error was controlled across multiples tests using a hierarchical testing strategy.
Empagliflozin significantly reduced the risk of first occurrence of primary composite endpoint of CV death, non-fatal myocardial infarction, or non-fatal stroke (HR: 0.86; 95% CI: 0.74, 0.99). The treatment effect was due to a significant reduction in the risk of CV death in subjects randomized to empagliflozin (HR: 0.62; 95% CI: 0.49, 0.77), with no change in the risk of non-fatal myocardial infarction or non-fatal stroke (see Table 7 and Figures 4 and 5). Results for the 10 mg and 25 mg empagliflozin dosages were consistent with results for the combined dosage groups.
Table 7 : Treatment Effect for the Primary Composite Endpoint and its Componentsa
|
Placebo
N=2,333 |
Empagliflozin
N=4,687 |
Hazard ratio vs placebo (95% CI) |
| Composite of CV death, non-fatal myocardial infarction, non-fatal stroke (time to first occurrence)b |
282 (12.1%) |
490 (10.5%) |
0.86
(0.74, 0.99) |
| Non-fatal myocardial infarctionc |
121 (5.2%) |
213 (4.5%) |
0.87
(0.70, 1.09) |
| Non-fatal strokec |
60 (2.6%) |
150 (3.2%) |
1.24
(0.92, 1.67) |
| CV deathc |
137 (5.9%) |
172 (3.7%) |
0.62
(0.49, 0.77) |
aTreated set (patients who had received at least one dose of trial drug)
bp-value for superiority (2-sided) 0.04
cTotal number of events |
Figure 4 : Estimated Cumulative Incidence of First MACE
Figure 5 : Estimated Cumulative Incidence of CV Death
The efficacy of empagliflozin on CV death was generally consistent across major demographic and disease subgroups.
Vital status was obtained for 99.2% of subjects in the trial. A total of 463 deaths were recorded during the EMPA-REG OUTCOME trial. Most of these deaths were categorized as CV deaths. The non-CV deaths were only a small proportion of deaths and were balanced between the treatment groups (2.1% in patients treated with empagliflozin, and 2.4% of patients treated with placebo).
Linagliptin Cardiovascular Safety Trials In Patients With Type 2 Diabetes Mellitus
CARMELINA
The CV risk of linagliptin was evaluated in CARMELINA, a multinational, multi-center, placebo-controlled, double-blind, parallel group trial comparing linagliptin (N=3,494) to placebo (N=3,485) in adult patients with type 2 diabetes mellitus and a history of established macrovascular and/or renal disease. The trial compared the risk of major adverse cardiovascular events (MACE) between linagliptin and placebo when these were added to standard of care treatments for diabetes mellitus and other CV risk factors. The trial was event driven, the median duration of follow-up was 2.2 years and vital status was obtained for 99.7% of patients.
Patients were eligible to enter the trial if they were adults with type 2 diabetes mellitus, with HbA1c of 6.5% to 10%, and had either albuminuria and previous macrovascular disease (39% of enrolled population), or evidence of impaired renal function by eGFR and Urinary Albumin Creatinine Ratio (UACR) criteria (42% of enrolled population), or both (18% of enrolled population).
At baseline the mean age was 66 years and the population was 63% male, 80% White, 9% Asian, 6% Black or African American and 36% were of Hispanic or Latino ethnicity. Mean HbA1c was 8.0% and mean duration of type 2 diabetes mellitus was 15 years. The trial population included 17% patients ≥75 years of age and 62% patients with renal impairment defined as eGFR <60 mL/min/1.73 m². The mean eGFR was 55 mL/min/1.73 m² and 27% of patients had mild renal impairment (eGFR 60 to 90 mL/min/1.73 m²), 47% of patients had moderate renal impairment (eGFR 30 to <60 mL/min/1.73 m²) and 15% of patients had severe renal impairment (eGFR <30 mL/min/1.73 m²). Patients were taking at least one antidiabetic drug (97%), and the most common were insulin and analogues (57%), metformin (54%) and sulfonylurea (32%). Patients were also taking antihypertensives (96%), lipid lowering drugs (76%) with 72% on statin, and aspirin (62%).
The primary endpoint, MACE, was the time to first occurrence of one of three composite outcomes which included CV death, non-fatal myocardial infarction or non-fatal stroke. The trial was designed as a noninferiority trial with a pre-specified risk margin of 1.3 for the hazard ratio of MACE. A total of 434 patients on linagliptin and 420 patients on placebo experienced MACE. The incidence rate of MACE in both treatment arms: 56.3 MACE per 1,000 patient-years on placebo vs. 57.7 MACE per 1,000 patient-years on linagliptin. The estimated hazard ratio for MACE associated with linagliptin relative to placebo was 1.02 with a 95% confidence interval of (0.89, 1.17). The upper bound of this confidence interval, 1.17, excluded the risk margin of 1.3.
CAROLINA
The CV risk of linagliptin was evaluated in CAROLINA, a multi-center, multinational, randomized, doubleblind parallel group trial comparing linagliptin (N=3,023) to glimepiride (N=3,010) in adult patients with type 2 diabetes mellitus and a history of established CV disease and/or multiple CV risk factors. The trial compared the risk of major adverse cardiovascular events (MACE) between linagliptin and glimepiride when these were added to standard of care treatments for diabetes mellitus and other CV risk factors. The trial was event driven, the median duration of follow-up was 6.23 years and vital status was obtained for 99.3% of patients.
Patients were eligible to enter the trial if they were adults with type 2 diabetes mellitus with insufficient glycemic control (defined as HbA1c of 6.5% to 8.5% or 6.5% to 7.5% depending on treatment-naïve, on monotherapy or on combination therapy), and were defined to be at high CV risk with previous vascular disease, evidence of vascular related end-organ damage, age ≥70 years, and/or two CV risk factors (duration of diabetes mellitus >10 years, systolic blood pressure >140 mmHg, current smoker, LDL cholesterol ≥135 mg/dL).
At baseline the mean age was 64 years and the population was 60% male, 73% White, 18% Asian, 5% Black or African American, and 17% were of Hispanic or Latino ethnicity. The mean HbA1c was 7.15% and mean duration of type 2 diabetes mellitus was 7.6 years. The trial population included 34% patients ≥70 years of age and 19% patients with renal impairment defined as eGFR <60 mL/min/1.73 m². The mean eGFR was 77 mL/min/1.73 m². Patients were taking at least one antidiabetic drug (91%) and the most common were metformin (83%) and sulfonylurea (28%). Patients were also taking antihypertensives (89%), lipid lowering drugs (70%) with 65% on statin, and aspirin (47%).
The primary endpoint, MACE, was the time to first occurrence of one of three composite outcomes which included CV death, non-fatal myocardial infarction or non-fatal stroke. The trial was designed as a noninferiority trial with a pre-specified risk margin of 1.3 for the hazard ratio of MACE. A total of 356 patients on linagliptin and 362 patients on glimepiride experienced MACE. The incidence rate of MACE in both treatment arms: 20.7 MACE per 1,000 patient-years on linagliptin vs. 21.2 MACE per 1,000 patient-years on glimepiride. The estimated hazard ratio for MACE associated with linagliptin relative to glimepiride was 0.98 with a 95% confidence interval of (0.84, 1.14). The upper bound of this confidence interval, 1.14, excluded the risk margin of 1.3.