Safety and Efficacy of Sitagliptin Compared With Glimepiride in Elderly Participants With Type 2 Diabetes Mellitus (MK-0431-251)

Safety and Efficacy of Sitagliptin Compared With Glimepiride in Elderly Participants With Type 2 Diabetes Mellitus (MK-0431-251)

A Phase III, Multicenter, Double-Blind, Randomized, Active-Controlled Study to Evaluate the Safety and Efficacy of Sitagliptin Compared With Glimepiride in Elderly Patients With Type 2 Diabetes Mellitus With Inadequate Glycemic Control

The primary objectives of this study are to determine if sitagliptin treatment is not inferior to that of glimepiride as measured by the change in baseline hemoglobin A1C (HbA1C) after 30 weeks of treatment, and if sitagliptin treatment results in a lower incidence of symptomatic hypoglycemia compared to that of glimepiride. The study will also evaluate if sitagliptin treatment, compared to glimepiride results in improvements in fasting plasma glucose (FPG) levels, and plasma lipid levels after 30 weeks of treatment. Participants will be randomized to either sitagliptin or glimepiride treatment after eligibility for study participation is determined during screening and washout study phases. Participants and study staff will not know to which treatment group they have been randomized (double-blind design). The duration of study participation will be up to 40 weeks (with 9 clinic visits). This will include a screening phase (Visit 1 to Visit 2) of 2 weeks maximum; a 6-week (Visits 2 to 3) oral antihyperglycemic agent (AHA) wash-out phase (for those who have been taking a AHA prior to the study); a placebo run-in phase (Visits 3 to 4), followed by up to 30 weeks of treatment with study medication.

The dose of sitagliptin will be 100 mg once daily (QD) or 50 mg QD based on the participant's estimated glomerular filtration rate (eGFR). The starting dose of glimepiride (1 mg QD) may be up-titrated as needed to optimize glycemic control over the first 18 weeks to a maximum dose of 6 mg/day, after which the dose will not be increased for the rest of the study (down-titration to avoid or control hypoglycemia is allowed).

Type 2 Diabetes Mellitus, Hemoglobin A1C, glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), dipeptidyl peptidase 4 inhibitor (DPP-4)

Sitagliptin tablets, orally, at a dose of 100 mg or 50 mg QD for 30 weeks. The dose level to be administered will depend on the participant's estimated glomerular filtration rate (eGFR), calculated at Visit 3 and may be adjusted as medically indicated during the study.

Glimepiride tablets, orally, starting at a dose of 1 mg QD, which may be gradually increased, as needed, to maximum dose of 6 mg QD for 30 weeks. The dose may also be decreased as medically indicated during the study.

Participant whole blood samples were collected at baseline and Week 30 to determine the LS mean HbA1c change from baseline. HbA1c is a measure of the percentage of glycated hemoglobin in the blood and provides an indication of participant blood glucose control in the 2 to 3 months prior to the evaluation.

Symptomatic hypoglycemia was defined as an episode with clinical symptoms attributed to hypoglycemia, without regard to glucose level. Participants were instructed to complete the Hypoglycemia Assessment Log (HAL) for any symptomatic episodes he or she believed represent hypoglycemia. If a fingerstick glucose was obtained before or shortly (i.e., within a few minutes) after treating, the value was recorded in the HAL. In addition, participants were instructed to record in the HAL any fingerstick glucose values ≤70 mg/dL (≤3.9 mmol/L) regardless of the presence of clinical symptoms.

An AE was defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study treatment, whether or not considered related to the use of the treatment administered.

An AE was defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the study treatment, whether or not considered related to the use of the treatment administered.

Plasma samples were collected from participants after an overnight fast at baseline and Week 30 to determine the mean change from baseline in participant FPG.

Participant whole blood samples were collected at Week 30 to determine the number of participants achieving HbA1c <7.0% at Week 30. HbA1c is a measure of the percentage of glycated hemoglobin in the blood and provides an indication of participant blood glucose control in the 2 to 3 months prior to the evaluation.

Participant whole blood samples were collected at Week 30 to determine the number of participants achieving HbA1c <6.5% at Week 30. Hemoglobin A1c is a measure of the percentage of glycated hemoglobin in the blood and provides an indication of participant blood glucose control in the 2 to 3 months prior to the evaluation.

Participants were only permitted to wear a drape gown and undergarments (no street clothes, no shoes or socks) for this evaluation. Body weight was measured after voiding (to the nearest 0.1 kg) and measurements were collected until 2 consecutive measurements did not differ by more than 0.2 kg from each other. Body weight measurements were evaluated using a standardized, calibrated digital scale and was reported in kilograms (kg) at baseline and Week 30.

Inclusion Criteria Diagnosis of type 2 diabetes mellitus Exclusion Criteria History of type 1 diabetes mellitus Has undergone a surgical procedure within the prior 4 weeks. Current participation in, or has participated, in another study with an investigational device or compound, with the prior 12 weeks, and/or is not willing to refrain from participating in any other study while participating in this study Hypersensitivity or contraindication to any sulfonylurea (e.g., glimepiride) medication Has been on an investigational or approved dipeptidyl peptidase-4 (DPP-4) inhibitor agent (e.g., sitagliptin, saxagliptin) Presence of human immunodeficiency virus (HIV) Current participation in a weight loss program or is receiving weight loss medication History of blood disorder, certain cancers, heart, liver or kidney disease Current or past use of recreational or illicit drugs, or a history of drug abuse or dependence, or increased alcohol consumption

http://www.merck.com/clinical-trials/pdf/Merck%20Procedure%20on%20Clinical%20Trial%20Data%20Access%20Final_Updated%20July_9_2014.pdf http://engagezone.msd.com/ds_documentation.php

Hartley P, Shentu Y, Betz-Schiff P, Golm GT, Sisk CM, Engel SS, Shankar RR. Efficacy and Tolerability of Sitagliptin Compared with Glimepiride in Elderly Patients with Type 2 Diabetes Mellitus and Inadequate Glycemic Control: A Randomized, Double-Blind, Non-Inferiority Trial. Drugs Aging. 2015 Jun;32(6):469-76. doi: 10.1007/s40266-015-0271-z.