CLINICAL PHARMACOLOGY
Mechanism Of Action
Alogliptin And Metformin Hydrochloride
KAZANO combines two antihyperglycemic agents with complementary
and distinct mechanisms of action to improve glycemic control in patients with
type 2 diabetes: alogliptin, a selective inhibitor of DPP-4, and metformin HCl,
a member of the biguanide class.
Alogliptin
Increased concentrations of the incretin hormones such as
glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic
polypeptide (GIP) are released into the bloodstream from the small intestine in
response to meals. These hormones cause insulin release from the pancreatic
beta cells in a glucose-dependent manner but are inactivated by the dipeptidyl
peptidase-4 (DPP-4) enzyme within minutes. GLP-1 also lowers glucagon secretion
from pancreatic alpha cells, reducing hepatic glucose production. In patients
with type 2 diabetes, concentrations of GLP-1 are reduced but the insulin
response to GLP-1 is preserved. Alogliptin is a DPP-4 inhibitor that slows the
inactivation of the incretin hormones, thereby increasing their bloodstream
concentrations and reducing fasting and postprandial glucose concentrations in
a glucose-dependent manner in patients with type 2 diabetes mellitus.
Alogliptin selectively binds to and inhibits DPP-4 but not DPP-8 or DPP-9
activity in vitro at concentrations approximating therapeutic exposures.
Metformin Hydrochloride
Metformin is a biguanide that improves glucose tolerance
in patients with type 2 diabetes, lowering both basal and postprandial plasma
glucose. Metformin decreases hepatic glucose production, decreases intestinal
absorption of glucose and improves insulin sensitivity by increasing peripheral
glucose uptake and utilization. Metformin does not produce hypoglycemia in
patients with type 2 diabetes or in healthy subjects except in special
circumstances [see WARNINGS AND PRECAUTIONS] and does not cause
hyperinsulinemia. With metformin therapy, insulin secretion remains unchanged
while fasting insulin levels and daylong plasma insulin response may actually
decrease.
Pharmacodynamics
Alogliptin
Single-dose administration of alogliptin to healthy
subjects resulted in a peak inhibition of DPP-4 within two to three hours after
dosing. The peak inhibition of DPP-4 exceeded 93% across doses of 12.5 mg to
800 mg. Inhibition of DPP-4 remained above 80% at 24 hours for doses greater
than or equal to 25 mg. Peak and total exposure over 24 hours to active GLP-1
were three-to four-fold greater with alogliptin (at doses of 25 to 200 mg) than
placebo. In a 16 week, double-blind, placebo-controlled study, alogliptin 25 mg
demonstrated decreases in postprandial glucagon while increasing postprandial
active GLP-1 levels compared to placebo over an eight hour period following a
standardized meal. It is unclear how these findings relate to changes in
overall glycemic control in patients with type 2 diabetes mellitus. In this
study, alogliptin 25 mg demonstrated decreases in two-hour postprandial glucose
compared to placebo (-30 mg/dL versus 17 mg/dL, respectively).
Multiple-dose administration of alogliptin to patients
with type 2 diabetes also resulted in a peak inhibition of DPP-4 within one to
two hours and exceeded 93% across all doses (25 mg, 100 mg and 400 mg) after a
single dose and after 14 days of once-daily dosing. At these doses of
alogliptin, inhibition of DPP-4 remained above 81% at 24 hours after 14 days of
dosing.
Pharmacokinetics
Absorption And Bioavailability
Alogliptin And Metformin Hydrochloride
In bioequivalence studies of KAZANO, the area under the
plasma concentration curve (AUC) and maximum concentration (Cmax) of both the
alogliptin and the metformin component following a single dose of the
combination tablet were bioequivalent to the alogliptin 12.5 mg concomitantly
administered with metformin HCl 500 or 1000 mg tablets under fasted conditions
in healthy subjects. Administration of KAZANO with food resulted in no change
in total exposure (AUC) of alogliptin and metformin. Mean peak plasma
concentrations of alogliptin and metformin were decreased by 13% and 28%,
respectively, when administered with food. There was no change in time to peak
plasma concentrations (Tmax) for alogliptin under fed conditions, however,
there was a delayed Tmax for metformin of 1.5 hours. These changes are not likely
to be clinically significant.
Alogliptin
The absolute bioavailability of alogliptin is
approximately 100%. Administration of alogliptin with a high-fat meal results
in no significant change in total and peak exposure to alogliptin. Alogliptin
may therefore be administered with or without food.
Metformin Hydrochloride
The absolute bioavailability of metformin following
administration of a 500 mg metformin HCl tablet given under fasting conditions
is approximately 50% to 60%. Studies using single oral doses of metformin HCl
tablets 500 mg to 1500 mg and 850 mg to 2550 mg indicate that there is a lack
of dose proportionality with increasing doses, which is due to decreased
absorption rather than an alteration in elimination. Food decreases the extent
of and slightly delays the absorption of metformin, as shown by approximately a
40% lower mean peak plasma concentration (Cmax), a 25% lower area under the
plasma concentration versus time curve (AUC), and a 35-minute prolongation of
time to peak plasma concentration (Tmax) following administration of a single
850 mg tablet of metformin HCl with food compared to the same tablet strength
administered fasting. The clinical relevance of these decreases is unknown.
Distribution
Alogliptin
Following a single, 12.5 mg intravenous infusion of
alogliptin to healthy subjects, the volume of distribution during the terminal
phase was 417 L, indicating that the drug is well distributed into tissues.
Alogliptin is 20% bound to plasma proteins.
Metformin Hydrochloride
The apparent volume of distribution (V/F) of metformin
following single oral doses of immediate release metformin HCl tablets 850 mg
averaged 654 ± 358 L. Metformin is negligibly bound to plasma proteins.
Metformin partitions into erythrocytes, most likely as a function of time. At
usual clinical doses and dosing schedules of metformin, steady-state plasma
concentrations of metformin are reached within 24 to 48 hours and are generally
less than 1 mcg/mL. During controlled clinical trials, which served as the
basis for approval for metformin, maximum metformin plasma levels did not
exceed 5 mcg/mL, even at maximum doses.
Metabolism
Alogliptin
Alogliptin does not undergo extensive metabolism and 60%
to 71% of the dose is excreted as unchanged drug in the urine.
Two minor metabolites were detected following
administration of an oral dose of [14C] alogliptin, Ndemethylated,
M-I (less than 1% of the parent compound), and N-acetylated alogliptin, M-II
(less than 6% of the parent compound). M-I is an active metabolite and is an
inhibitor of DPP-4 similar to the parent molecule; M-II does not display any
inhibitory activity toward DPP-4 or other DPP-related enzymes. In vitro data
indicate that CYP2D6 and CYP3A4 contribute to the limited metabolism of
alogliptin.
Alogliptin exists predominantly as the (R)-enantiomer
(more than 99%) and undergoes little or no chiral conversion in vivo to the (S)-enantiomer.
The (S)-enantiomer is not detectable at the 25 mg dose.
Metformin Hydrochloride
Intravenous single-dose studies in healthy subjects
demonstrate that metformin is excreted unchanged in the urine and does not
undergo hepatic metabolism (no metabolites have been identified in humans) or
biliary excretion.
Excretion And Elimination
Alogliptin
The primary route of elimination of [14C]
alogliptin-derived radioactivity occurs via renal excretion (76%) with 13%
recovered in the feces, achieving a total recovery of 89% of the administered
radioactive dose. The renal clearance of alogliptin (9.6 L/hr) indicates some
active renal tubular secretion and systemic clearance was 14.0 L/hr.
Metformin Hydrochloride
Renal clearance is approximately 3.5 times greater than
creatinine clearance, which indicates that tubular secretion is the major route
of metformin elimination. Following oral administration, approximately 90% of
the absorbed drug is eliminated via the renal route within the first 24 hours,
with a plasma elimination half-life of approximately 6.2 hours. In blood, the
elimination half-life is approximately 17.6 hours, suggesting that the
erythrocyte mass may be a compartment of distribution.
Special Populations
Renal Impairment
Metformin Hydrochloride
In patients with decreased renal function (based on
measured creatine clearance), the plasma and blood half-life of metformin is
prolonged and the renal clearance is decreased [see CONTRAINDICATIONS, WARNINGS
AND PRECAUTIONS].
Hepatic Impairment
Alogliptin
Total exposure to alogliptin was approximately 10% lower
and peak exposure was approximately 8% lower in patients with moderate hepatic
impairment (Child-Pugh Grade B) compared to healthy subjects. The magnitude of
these reductions is not considered to be clinically meaningful. Patients with
severe hepatic impairment (Child-Pugh Grade C) have not been studied.
Metformin Hydrochloride
No pharmacokinetic studies of metformin have been
conducted in subjects with hepatic impairment.
Gender
Alogliptin
No dose adjustment is necessary based on gender. Gender
did not have any clinically meaningful effect on the pharmacokinetics of
alogliptin.
Metformin Hydrochloride
Metformin pharmacokinetic parameters did not differ significantly
between normal subjects and patients with type 2 diabetes when analyzed
according to gender. Similarly, in controlled clinical studies in patients with
type 2 diabetes, the antihyperglycemic effect of metformin hydrochloride
tablets was comparable in males and females.
Geriatric
Due to declining renal function in the elderly,
measurement of creatinine clearance should be obtained prior to initiation of
therapy.
Alogliptin
No dose adjustment is necessary based on age. Age did not
have any clinically meaningful effect on the pharmacokinetics of alogliptin.
Metformin Hydrochloride
Limited data from controlled pharmacokinetic studies of
metformin in healthy elderly subjects suggest that total plasma clearance of
metformin is decreased, the half-life is prolonged, and Cmax is increased,
compared to healthy young subjects. From these data it appears that the change
in metformin pharmacokinetics with aging is primarily accounted for by a change
in renal function.
Pediatrics
Studies characterizing the pharmacokinetics of alogliptin
in pediatric patients have not been performed.
Race
Alogliptin
No dose adjustment of alogliptin is necessary based on
race. Race (white, black and Asian) did not have any clinically meaningful
effect on the pharmacokinetics of alogliptin.
Metformin Hydrochloride
No studies of metformin pharmacokinetic parameters according
to race have been performed. In controlled clinical studies of metformin in
patients with type 2 diabetes, the antihyperglycemic effect was comparable in
whites (n=249), blacks (n=51) and Hispanics (n=24).
Drug Interactions
Alogliptin And Metformin Hydrochloride
Administration of alogliptin 100 mg once daily with
metformin HCl 1000 mg twice daily for six days had no meaningful effect on the
pharmacokinetics of alogliptin or metformin.
Specific pharmacokinetic drug interaction studies with
KAZANO have not been performed, although such studies have been conducted with
the individual components of KAZANO (alogliptin and metformin).
Alogliptin
In Vitro Assessment Of Drug Interactions
In vitro studies indicate that alogliptin is neither an
inducer of CYP1A2, CYP2B6, CYP2C9, CYP2C19 and CYP3A4, nor an inhibitor of
CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP3A4 and CYP2D6 at clinically relevant
concentrations.
In Vivo Assessment Of Drug Interactions
Effects Of Alogliptin On The Pharmacokinetics Of Other
Drugs
In clinical studies, alogliptin did not meaningfully
increase the systemic exposure to the following drugs that are metabolized by
CYP isozymes or excreted unchanged in urine (Figure 1). No dose adjustment of
alogliptin is recommended based on results of the described pharmacokinetic
studies.
Figure 1: Effect of Alogliptin on the Pharmacokinetic
Exposure to Other Drugs
*Warfarin was given once daily
at a stable dose in the range of 1 mg to 10 mg. Alogliptin had no significant
effect on the prothrombin time (PT) or International Normalized Ratio (INR).
**Caffeine (1A2 substrate),
tolbutamide (2C9 substrate), dextromethorphan (2D6 substrate), midazolam (3A4
substrate) and fexofenadine (P-gp substrate) were administered as a cocktail.
Effects Of Other Drugs On The Pharmacokinetics
Of Alogliptin
There are no clinically
meaningful changes in the pharmacokinetics of alogliptin when alogliptin is
administered concomitantly with the drugs described below (Figure 2).
Figure 2: Effect of Other Drugs on the Pharmacokinetic
Exposure of Alogliptin
Metformin Hydrochloride
Pharmacokinetic drug
interaction studies have been performed on metformin (Tables 4 and 5).
Table 4: Effect of Coadministered Drug on Plasma
Metformin Systemic Exposure
Coadministered Drug |
Dose of Coadministered Drug* |
Dose of Metformin HCl* |
Geometric Mea with/without coad No effec |
in Ratio (ratio ministered drug) = 1.00 |
AUC† |
Cmax |
No dosing adjustments required for the following: |
Glyburide |
5 mg |
500 mg‡ |
0.98§ |
0.99§ |
Furosemide |
40 mg |
850 mg |
1.09§ |
1.22§ |
Nifedipine |
10 mg |
850 mg |
1.16 |
1.21 |
Propranolol |
40 mg |
850 mg |
0.90 |
0.94 |
Ibuprofen |
400 mg |
850 mg |
1.05§ |
1.07§ |
Drugs that are eliminated by renal tubular secretion may increase the accumulation of metformin [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS]. |
Cimetidine |
400 mg |
850 mg |
1.40 |
1.61 |
Carbonic anhydrase inhibitors may cause metabolic acidosis [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS] |
Topiramate |
100 mg¶ |
500 mg¶ |
1.25¶ |
1.17 |
*All metformin and
coadministered drugs were given as single doses
†AUC = AUC0-∞
‡metformin hydrochloride extended-release tablets 500 mg
§Ratio of arithmetic means
¶At steady-state with topiramate 100 mg every 12 hours and metformin 500 mg
every 12 hours; AUC = AUC012h |
Table 5: Effect of Metformin on Coadministered Drug Systemic Exposure
Coadministered Drug |
Dose of Coadministered Drug* |
Dose of Metformin HCl* |
Geometric Mean Ratio (ratio with/without coadministered drug) No effect = 1.00 |
AUC† |
Cmax |
No dosing adjustments required for the following: |
Glyburide |
5 mg |
500 mg‡ |
0.78§ |
0.63§ |
Furosemide |
40 mg |
850 mg |
0.87§ |
0.69§ |
Nifedipine |
10 mg |
850 mg |
1.10‡ |
1.08 |
Propranolol |
40 mg |
850 mg |
1.01‡ |
0.94 |
Ibuprofen |
400 mg |
850 mg |
0.97¶ |
1.01¶ |
Cimetidine |
400 mg |
850 mg |
0.95‡ |
1.01 |
*All metformin and
coadministered drugs were given as single doses
†AUC = AUC0-∞
‡AUC0-24 hr reported
§Ratio of arithmetic means, p-value of difference <0.05
¶Ratio of arithmetic means |
Clinical Studies
The coadministration of alogliptin and metformin has been
studied in patients with type 2 diabetes inadequately controlled on either diet
and exercise alone, on metformin alone or metformin in combination with a
thiazolidinedione.
There have been no clinical efficacy studies conducted
with KAZANO; however, bioequivalence of KAZANO with coadministered alogliptin
and metformin tablets was demonstrated, and efficacy of the combination of
alogliptin and metformin has been demonstrated in three Phase 3 efficacy
studies.
A total of 2095 patients with type 2 diabetes were
randomized in three double-blind, placebo-or active-controlled clinical safety
and efficacy studies conducted to evaluate the effects of KAZANO on glycemic
control. The racial distribution of patients exposed to study medication was
69.2% white, 16.3% Asian, 6.5% black and 8.0% other racial groups. The ethnic
distribution was 24.3% Hispanic. Patients had an overall mean age of
approximately 54.4 years (range 22 to 80 years). In patients with type 2
diabetes, treatment with KAZANO produced clinically meaningful and
statistically significant improvements in A1C versus comparator. As is typical
for trials of agents to treat type 2 diabetes, the mean reduction in hemoglobin
A1c (A1C) with KAZANO appears to be related to the degree of A1C elevation at
baseline.
Alogliptin And Metformin Coadministration In Patients With
Type 2 Diabetes Inadequately Controlled On Diet and Exercise
In a 26 week, double-blind, placebo-controlled study, a
total of 784 patients inadequately controlled on diet and exercise alone (mean
baseline A1C = 8.4%) were randomized to one of seven treatment groups: placebo;
metformin HCl 500 mg or metformin HCl 1000 mg twice daily, alogliptin 12.5 mg
twice daily, or alogliptin 25 mg daily; alogliptin 12.5 mg in combination with
metformin HCl 500 mg or metformin HCl 1000 mg twice daily. Both
coadministration treatment arms (alogliptin 12.5 mg + metformin HCl 500 mg and
alogliptin 12.5 mg + metformin HCl 1000 mg) resulted in significant
improvements in A1C (Figure 3) and FPG when compared with their respective
individual alogliptin and metformin component regimens (Table 6).
Coadministration treatment arms demonstrated improvements in two-hour
postprandial glucose (PPG) compared to alogliptin alone or metformin alone (Table
6). A total of 12% of patients receiving alogliptin 12.5 mg + metformin HCl 500
mg, 3% of patients receiving alogliptin 12.5 mg + metformin HCl 1000 mg, 17% of
patients receiving alogliptin 12.5 mg, 23% of patients receiving metformin HCl
500 mg, 11% of patients receiving metformin HCl 1000 mg and 39% of patients
receiving placebo required glycemic rescue.
Improvements in A1C were not affected by gender, age,
race or baseline BMI. The mean decrease in body weight was similar between
metformin alone and alogliptin when coadministered with metformin. Lipid
effects were neutral.
Table 6: Glycemic Parameters at Week 26 for Alogliptin
and Metformin Alone and in Combination in Patients with Type 2 Diabetes
|
Placebo |
Alogliptin 12.5 mg twice daily |
Metformin HCl 500 mg twice daily |
Metformin HCl 1000 mg twice daily |
Alogliptin 12.5 mg + Metformin HCl 500 mg twice daily |
Alogliptin 12.5 mg + Metformin HCl 1000 mg twice daily |
A1C (%)* |
N=102 |
N=104 |
N=103 |
N=108 |
N=102 |
N=111 |
Baseline (mean) |
8.5 |
8.4 |
8.5 |
8.4 |
8.5 |
8.4 |
Change from baseline (adjusted mean†) |
0.1 |
-0.6 |
-0.7 |
-1.1 |
-1.2 |
-1.6 |
Difference from metformin (adjusted mean†with 95% confidence interval) |
- |
- |
- |
- |
-0.6‡ (-0.9, -0.3) |
-0.4‡ (-0.7, -0.2) |
Difference from alogliptin (adjusted mean† with 95% confidence interval) |
- |
- |
- |
- |
-0.7‡ (-1.0, -0.4) |
-1.0‡ (-1.3, -0.7) |
% of Patients (n/N) achieving A1C <7%§ |
4% (4/102) |
20% (21/104) |
27% (28/103) |
34% (37/108) |
47%‡ (48/102) |
59%‡ (66/111) |
FPG (mg/dL)* |
N=105 |
N=106 |
N=106 |
N=110 |
N=106 |
N=112 |
Baseline (mean) |
187 |
177 |
180 |
181 |
176 |
185 |
Change from baseline (adjusted mean†) |
12 |
-10 |
-12 |
-32 |
-32 |
-46 |
Difference from metformin (adjusted mean†with 95% confidence interval) |
- |
- |
- |
- |
-20‡ (-33, -8) |
-14‡ (-26, -2) |
Difference from alogliptin (adjusted mean† with 95% confidence interval) |
- |
- |
- |
- |
-22‡ (-35, -10) |
-36‡ (-49, -24) |
2-Hour PPG (mg/dL)¶ |
N=26 |
N=34 |
N=28 |
N=37 |
N=31 |
N=37 |
Baseline (mean) |
263 |
272 |
247 |
266 |
261 |
268 |
Change from baseline (adjusted mean†) |
-21 |
-43 |
-49 |
-54 |
-68 |
-86‡ |
Difference from metformin (adjusted mean† with 95% confidence interval) |
- |
- |
- |
- |
-19 (-49, 11) |
-32‡ (-58, -5) |
Difference from alogliptin (adjusted mean† with 95% confidence interval) |
- |
- |
- |
- |
-25 (-53, 3) |
-43‡ (-70, -16) |
*Intent-to-treat population
using last observation on study prior to discontinuation of double-blind study
medication or sulfonylurea rescue therapy for patients needing rescue
†Least squares means adjusted for treatment, geographic region and
baseline value
‡p<0.05 when compared to metformin and alogliptin alone
§Compared using logistic regression
¶Intent-to-treat population using data available at Week 26 |
Figure 3: Change from Baseline A1C at Week 26 with
Alogliptin and Metformin Alone and Alogliptin in Combination with Metformin
Alogliptin And Metformin
Coadministration In Patients With Type 2 Diabetes Inadequately Controlled On Metformin
Alone
In a 26 week, double-blind,
placebo-controlled study, a total of 527 patients already on metformin (mean
baseline A1C = 8%) were randomized to receive alogliptin 12.5 mg, alogliptin 25
mg, or placebo once daily. Patients were maintained on a stable dose of
metformin HCl (median daily dose = 1700 mg) during the treatment period.
Alogliptin 25 mg in combination with metformin resulted in statistically
significant improvements from baseline in A1C and FPG at Week 26, when compared
to placebo (Table 7). A total of 8% of patients receiving alogliptin 25 mg and
24% of patients receiving placebo required glycemic rescue. Improvements in A1C
were not affected by gender, age, race, baseline BMI or baseline metformin
dose.
The mean decrease in body
weight was similar between alogliptin 25 mg and placebo when given in
combination with metformin. Lipid effects were also neutral.
Table 7: Glycemic Parameters at Week 26 in a
Placebo-Controlled Study of Alogliptin as Add-on Therapy to Metformin*
|
Alogliptin 25 mg + Metformin |
Placebo + Metformin |
A1C (%) |
N=203 |
N=103 |
Baseline (mean) |
7.9 |
8.0 |
Change from baseline (adjusted mean†) |
-0.6 |
-0.1 |
Difference from placebo (adjusted mean† with 95% confidence interval) |
-0.5‡ (-0.7, -0.3) |
- |
% of patients (n/N) achieving A1C <7%* |
44% (92/207)‡ |
18% (19/104) |
FPG (mg/dL) |
N=204 |
N=104 |
Baseline (mean) |
172 |
180 |
Change from baseline (adjusted mean†) |
-17 |
0 |
Difference from placebo (adjusted mean† with 95% confidence interval) |
-17‡ (-26, -9) |
- |
*Intent-to-treat population
using last observation on study.
†Least squares means adjusted for treatment, baseline value, geographic
region and baseline metformin dose.
‡p<0.001 compared to placebo. |
Alogliptin Add-On Therapy In Patients
With Type 2 Diabetes Inadequately Controlled On The Combination Of Metformin And
Pioglitazone
In a 52 week, active-comparator
study, a total of 803 patients inadequately controlled (mean baseline A1C =
8.2%) on a current regimen of pioglitazone 30 mg and metformin were randomized
to either receive the addition of once-daily alogliptin 25 mg or the titration
of pioglitazone 30 mg to 45 mg following a four-week single-blind, placebo
run-in period. Patients were maintained on a stable dose of metformin HCl
(median daily dose = 1700 mg). Patients who failed to meet prespecified hyperglycemic
goals during the 52 week treatment period received glycemic rescue therapy.
In combination with
pioglitazone and metformin, alogliptin 25 mg was shown to be statistically
superior in lowering A1C and FPG compared with the titration of pioglitazone from
30 to 45 mg at Week 26 and at Week 52 (Table 8). A total of 11% of patients in
the alogliptin 25 mg in combination with pioglitazone 30 mg and metformin
treatment group and 22% of patients in the up titration of pioglitazone in
combination with metformin treatment group required glycemic rescue.
Improvements in A1C were not affected by gender, age, race or baseline BMI.
The mean increase in body
weight was similar in both treatment arms. Lipid effects were neutral.
Table 8: Glycemic Parameters at Week 52 in an
Active-Controlled Study of Alogliptin as Add-On Combination Therapy to
Metformin and Pioglitazone*
|
Alogliptin 25 mg + Pioglitazone 30 mg + Metformin |
Pioglitazone 45 mg + Metformin |
A1C (%) |
N=397 |
N=394 |
Baseline (mean) |
8.2 |
8.1 |
Change from baseline (adjusted mean†) |
-0.7 |
-0.3 |
Difference from pioglitazone 45 mg + metformin* (adjusted mean† with 95% confidence interval) |
-0.4‡ (-0.5, -0.3) |
- |
% of Patients (n/N) achieving A1C ≤7% |
33% (134/404)§ |
21% (85/399) |
Fasting Plasma Glucose (mg/dL)‡ |
N=399 |
N=396 |
Baseline (mean) |
162 |
162 |
Change from baseline (adjusted mean†) |
-15 |
-4 |
Difference from pioglitazone 45 mg + metformin (adjusted mean† with 95% confidence interval) |
-11§ (-16, -6) |
- |
*Intent-to-treat population using last observation on
study
†Least squares means adjusted for treatment, baseline value, geographic region
and baseline metformin dose
‡Noninferior and statistically superior to metformin + pioglitazone at the
0.025 one-sided significance level
§p<0.001 compared to pioglitazone 45 mg + metformin |
Cardiovascular Safety Trial
A randomized, double-blind,
placebo-controlled cardiovascular outcomes trial (EXAMINE) was conducted to
evaluate the cardiovascular risk of alogliptin. The trial compared the risk of
major adverse cardiovascular events (MACE) between alogliptin (N=2701) and
placebo (N=2679) when added to standard of care therapies for diabetes and
atherosclerotic vascular disease (ASCVD). The trial was event driven and
patients were followed until a sufficient number of primary outcome events
accrued.
Eligible patients were adults
with type 2 diabetes who had inadequate glycemic control at baseline (e.g.,
HbA1c >6.5%) and had been hospitalized for an acute coronary syndrome event
(e.g., acute myocardial infarction or unstable angina requiring
hospitalization) 15 to 90 days prior to randomization. The dose of alogliptin
was based on estimated renal function at baseline per dosage and administration
recommendations. The average time between an acute coronary syndrome event and
randomization was approximately 48 days.
The mean age of the population was 61 years. Most
patients were male (68%), Caucasian (73%), and were recruited from outside of
the United States (86%). Asian and Black patients contributed 20% and 4% of the
total population, respectively. At the time of randomization patients had a diagnosis
of type 2 diabetes mellitus for approximately 9 years, 87% had a prior
myocardial infarction and 14% were current smokers. Hypertension (83%) and
renal impairment (27% with an eGFR ≤60 ml/min/1.73 m²) were prevalent
co-morbid conditions. Use of medications to treat diabetes (e.g., metformin
73%, sulfonylurea 54%, insulin 41%), and ASCVD (e.g., statin 94%, aspirin 93%,
reninangiotensin system blocker 88%, beta-blocker 87%) was similar between
patients randomized to alogliptin and placebo at baseline. During the trial,
medications to treat diabetes and ASCVD could be adjusted to ensure care for
these conditions adhered to standard of care recommendations set by local
practice guidelines.
The primary endpoint in EXAMINE
was the time to first occurrence of a MACE defined as the composite of
cardiovascular death, nonfatal myocardial infarction (MI), or nonfatal stroke.
The study was designed to exclude a pre-specified risk margin of 1.3 for the
hazard ratio of MACE. The median exposure to study drug was 526 days and 95% of
the patients were followed to study completion or death.
Table 9 shows the study results
for the primary MACE composite endpoint and the contribution of each component
to the primary MACE endpoint. The upper bound of the confidence interval was
1.16 and excluded a risk margin larger than 1.3.
Table 9: Patients with MACE in EXAMINE
Composite of first event of CV death, nonfatal MI or nonfatal stroke (MACE) |
Alogliptin |
Placebo |
Hazard Ratio |
Number of Patients (%) |
Rate per 100 PY* |
Number of Patients (%) |
Rate per 100 PY* |
(98% CI) |
N=2701 |
|
N=2679 |
|
|
|
305 (11.3) |
7.6 |
316 (11.8) |
7.9 |
0.96 (0.80, 1.16) |
CV Death |
89 (3.3) |
2.2 |
111 (4.1) |
2.8 |
|
Non-fatal MI |
187 (6.9) |
4.6 |
173 (6.5) |
4.3 |
|
Non-fatal stroke |
29 (1.1) |
0.7 |
32 (1.2) |
0.8 |
|
*Patient Years (PY) |
The Kaplan-Meier based
cumulative event probability is presented in Figure 4 for the time to first
occurrence of the primary MACE composite endpoint by treatment arm. The curves
for placebo and alogliptin overlap throughout the duration of the study. The
observed incidence of MACE was highest within the first 60 days after
randomization in both treatment arms (14.8 MACE per 100 PY), decreased from day
60 to the end of the first year (8.4 per 100 PY) and was lowest after 1 year of
follow-up (5.2 per 100 PY).
Figure 4: Observed Cumulative Rate of MACE in EXAMINE
The rate of all cause death was similar between treatment
arms with 153 (3.6 per 100 PY) recorded among patients randomized to alogliptin
and 173 (4.1 per 100 PY) among patients randomized to placebo. A total of 112
deaths (2.9 per 100 PY) among patients on alogliptin and 130 among patients on
placebo (3.5 per 100 PY) were adjudicated as cardiovascular deaths.