Perspectives on Some Controversies in Cardiovascular Disease Risk Assessment in the Pharmaceutical Development of Glucose-Lowering Medications.

The U.S. Food and Drug Administration (FDA) issued guidance on requirements to assess cardiovascular disease (CVD) risk with drugs being developed for approval for clinical use. The guidance was triggered by a meta-analysis published by Nissen and Wolski that suggested an increased risk for myocardial infarction with the use of rosiglitazone. This article discusses controversies around CVD trials in diabetes beginning with the University Group Diabetes Program. This is followed by a brief description of the FDA guidance for evaluating CVD risk with glucose-lowering medications. Limitations of meta-analyses of data from phase 2 and 3 (phase 2/3) trials to inform CVD risk are highlighted. These include the differences between patient characteristics in phase 2/3 trials and those in cardiovascular outcome trials (CVOTs) and the relatively short exposure time in phase 2/3 trials. The differences may partly explain the observed disparity between phase 2/3 meta-analyses and the results of completed CVOTs. Approaches to understanding CVD risk with a new medication should get to the answer about risk as efficiently as possible to minimize any potential harm to patients. In that context, we discuss options for clinical trial design and an alternative approach for statistical analyses.

Baseline characteristics of participants in the Raloxifene Use for The Heart (RUTH) trial.

The Raloxifene Use for The Heart (RUTH) trial is a randomized, placebo-controlled, double-blind trial designed to determine whether raloxifene 60 mg/day compared with placebo lowers the risk of coronary events (coronary death, nonfatal myocardial infarction [MI], or hospitalized acute coronary syndromes other than MI) and reduces the risk of invasive breast cancer in women at risk for a major coronary event. Raloxifene is a selective estrogen receptor modulator that improves cardiovascular risk factors, reduces the risk of vertebral fracture, and is associated with a reduced incidence of invasive breast cancer in postmenopausal women with osteoporosis. Between June 1998 and August 2000, 10,101 women were enrolled at 187 sites in 26 countries. Approximately half of the women had documented coronary heart disease (CHD) (n = 5,031); the remainder had multiple CHD risk factors that increased their risk for a CHD event (n = 5,070). The mean age of participants was 68 years (39% were >70 years old), and did not differ between those with documented CHD and those at increased CHD risk. Most women were Caucasian (84%); 60% had a body mass index >/=27 kg/m(2), 46% had diabetes mellitus, 78% had systemic hypertension, and 14% had low-density lipoprotein cholesterol >160 mg/dl. Compared with women at increased CHD risk, women with documented CHD had higher cardiovascular risk scores, a higher prevalence of abnormal electrocardiograms, greater use of cardiovascular medications, were more likely to have had cardiac rehabilitation, and were more likely to have previously used estrogen or oral contraceptives, but had a slightly lower prevalence of CHD risk factors such as smoking, obesity, diabetes mellitus, and systemic hypertension, and had lower serum levels of total and low-density lipoprotein cholesterol. The RUTH cohort is the largest group of postmenopausal women at increased risk of CHD events ever assembled in a clinical trial, and is the first trial designed to determine the effect of a selective estrogen receptor modulator on the risk of CHD events.

Safety and adverse effects associated with raloxifene: multiple outcomes of raloxifene evaluation.

OBJECTIVE: To examine the effect of raloxifene on major adverse events that occur with postmenopausal estrogen therapy or tamoxifen. METHODS: The Multiple Outcomes of Raloxifene Evaluation, a multicenter, randomized, double-blind trial, enrolled 7,705 postmenopausal women with osteoporosis. Women were randomly assigned to raloxifene 60 mg/d or 120 mg/d or placebo. Outcomes included venous thromboembolism, cataracts, gallbladder disease, and endometrial hyperplasia or cancer. RESULTS: During a mean follow-up of 3.3 years, raloxifene was associated with an increased risk for venous thromboembolism (relative risk [RR] 2.1; 95% confidence interval [CI] 1.2-3.8). The excess event rate was 1.8 per 1,000 woman-years (95% CI -0.5-4.1), and the number needed to treat to cause 1 event was 170 (95% CI 100-582) over 3.3 years. Risk in the raloxifene group was higher than in the placebo group for the first 2 years, but decreased to about the same rate as in the placebo group thereafter. Raloxifene did not increase risk for cataracts (RR 0.9; 95% CI 0.8-1.1), gallbladder disease (RR 1.0; 95% CI 0.7-1.3), endometrial hyperplasia (RR 1.3; 95% CI 0.4-5.1), or endometrial cancer (RR 0.9; 95% CI 0.3-2.7). CONCLUSION: Raloxifene was associated with an increased risk for venous thromboembolism, but there was no increased risk for cataracts, gallbladder disease, endometrial hyperplasia, or endometrial cancer. LEVEL OF EVIDENCE: I