Table 2.

Summary of clinical trials involving incretin agents

INCRETIN AGENT AND COMBINATION	COMPARATOR	N	DURATION, WK	MEAN CHANGE IN HBA_1C, %^*
Sitagliptin
• Monotherapy35,38–43	Placebo	2389	12–24	−0.44 to −0.66
• Metformin35,40,44	Placebo	1437	24	−0.67 to −1.90
• Metformin15,35	Glipizide	1172	52	−0.67
• Glimepiride with or without metformin35,45	Placebo	441	24	−0.45
• Pioglitazone35,46	Placebo	353	24	−0.85
• Metformin47	Exenatide	61	2	NA
Vildagliptin
• Monotherapy35,48–53	Placebo	2253	12–52	−0.20 to −0.92
• Metformin54,55	Placebo	651	12–24	−0.60 to −0.90
• Insulin56	Placebo	296	24	−0.50
• Metformin16	Pioglitazone	576	24	−0.88
• Pioglitazone57	Placebo	463	24	−1.00
• Various59	Vildagliptin vs pioglitazone vs vildagliptin and pioglitazone	607	24	−1.1
Exenatide
• Sulfonylurea24	Placebo	377	30	−0.86
• Metformin25	Placebo	336	30	−0.8
• Metformin and sulfonylurea26	Placebo	733	30	−0.75^†
• TZD with or without metformin27	Placebo	233	16	−0.89
• Metformin and sulfonylurea20,21	Insulin glargine	689	26–32	−1.36 to −1.16
• Metformin and sulfonylurea22	Biphasic insulin	501	52	−1.04
• Monotherapy31	Placebo	232	24	−0.9
• Metformin, sulfonylurea, or both28	None	314	82	−1.1
• Metformin, sulfonylurea, or both59	Placebo	217	156	−1.0
Liraglutide
• Monotherapy (LEAD-3)18	Glimepiride	746	52	−0.84 to −1.14
• Metformin (LEAD-2)33	Placebo or glimepiride	1091	26	−1.0
• Glimepiride (LEAD-1)32	Placebo or rosiglitazone	1041	26	−1.1
• Metformin and rosiglitazone (LEAD-4)34	Placebo	533	26	−1.5
• Metformin and sulfonylurea (LEAD-5)23	Insulin glargine	581	26	−1.33
• Previous oral antihyperglycemics (LEAD-6)60	Exenatide plus previous oral antihyperglycemics	464	26	−1.12

HbA_1c—glycated hemoglobin A_1c, LEAD—Liraglutide Effect and Action in Diabetes, NA—not applicable, TZD—thiazolidinedione.
↵* Reported mean change from baseline in patients treated with incretin agents. Where several values are provided (eg, different doses of the study drug), either in a single report or in multiple reports, the range of reported mean values is shown.
↵† Precise value not reported; reduction in HbA_1c levels was shown in a figure.