The supporting data come from several clinical trials, including the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study, as well as the Irbesartan Diabetic Nephropa thy Trial (IDNT
(5) However, a survival benefit was not seen with irbesartan in the RENAAL and IDNT
Findings from the Irbesartan Diabetic Nephropathy Trial (IDNT
) and the Reduction of Endpoints in NIDDM with Angiotensin II Antagonist Losartan (RENAAL) indicate that ARBs are more effective than other agents in slowing the progression of kidney disease in patients with macroalbuminuria due to type 2 diabetes.
In the end, the panelists were swayed instead by the accumulation of data from both the RENAAL study and from the Irbesartan Diabetic Nephropathy Trial (IDNT), which involved an agent from the same class as losartan.
Other panelists who voted against approval, warned about the dangers of extrapolating data from IDNT simply because irbesartan and losartan are from the same class.
Lewis, the lead investigator of the study that led to captopril's approval for nephropathy, was also the lead investigator of the Irbesartan Diabetic Nephropathy Trial (IDNT), one of the two studies of the ARB in hypertensive type 2 diabetics presented at the meeting.
IDNT compared 300 mg of irbesartan with 10 mg of the calcium channel blocker amlodipine and placebo in 1,712 patients, most of whom were white and male, with overt nephropathy.
The panel unanimously agreed that the IDNT study alone was not an adequate basis for approval, and 10 of the 11 panelists agreed that while the IRMA-2 data were supportive, the two studies together were not an adequate basis for approval.
The Irbesartan Diabetic Nephropathy Trial (IDNT) randomized 1,715 patients with diabetic nephropathy and hypertension to one of three arms: 300 mg/day irbesartan, 10 mg of the calcium channel blocker amlodipine per day, or placebo.
The IDNT and the IRMA II trials were funded by Bristol-Myers Squibb Co.