Designs of RADIANCE 1 and 2: carotid ultrasound studies comparing the effects of torcetrapib/atorvastatin with atorvastatin alone on atherosclerosis

Abstract

Objective: The RADIANCE studies were designed to assess the effects of torcetrapib/atorvastatin (T/A) compared with atorvastatin alone on slowing atherosclerotic progression in patients with heterozygous familial hypercholesterolemia (RADIANCE 1) or mixed hyperlipidemia (RADIANCE 2), as measured by change in carotid intima-media thickness (CIMT).

Research design and methods: RADIANCE 1 and 2 were randomized, double-blind, controlled trials with a duration of 2 years. In both studies, eligible subjects began treatment with atorvastatin during a run-in period and were titrated to target LDL-C levels defined by NCEP ATP III guidelines. Subjects then proceeded to a double-blind randomized treatment period where they received one of two regimens: (i) fixed combination T/A (torcetrapib dose, 60 mg), or (ii) atorvastatin alone. In both regimens, the dose of atorvastatin was established during the run-in period (20-80 mg, RADIANCE 1; 10-80 mg RADIANCE 2). B-mode ultrasonography was performed in duplicate at baseline and at end of study, and every 6 months in between.

Main outcome measures: The primary efficacy measure in both studies was the annualized rate of change in maximum CIMT of 12 pre-defined carotid segments. Further outcome measures included lipid and safety assessments.

Current status: The number of subjects randomized was 904 in RADIANCE 1 and 752 in RADIANCE 2. Results are anticipated in 2007.

Trial registration: ClinicalTrials.gov NCT00134238 NCT00136981.