HMG-CoA REDUCTASE INHIBITORS: NHLBI PILOT STUDY

Executive Summary

HMG-CoA REDUCTASE INHIBITORS: NHLBI PILOT STUDY will assess the short-term safety and efficacy of the cholesterol-lowering agent in men and women aged 65 and older. In January, the National Heart, Lung and Blood Institute will begin recruiting a total of 500 patients at five centers. The 12-18 month, $2.5 mil. pilot study is part of NHLBI's Cholesterol Reduction in Seniors Program (CRISP). Participants must have an LDL cholesterol level between 160 and 220 mg/dl at entry that remains over 120 mg/dl after the introduction of a cholesterol-lowering diet. Subjects will be randomized to receive either placebo; low-dose HMG-CoA, i.e., 20 mg lovastatin (Merck's Mevacor), 20 mg pravastatin (Bristol-Myers Squibb's Pravachol) or 10 mg simvastatin (Merck's Zocor); or high-dose HMG-CoA -- 40 mg lovastatin, 40 mg pravastatin or 20 mg simvastatin. Neither Pravachol nor Zocor has been approved for marketing in the U.S. Pravachol is scheduled to be reviewed by FDA's Endocrinologic and Metabolic Drugs Advisory Committee during the second day of its Oct. 22-23 meeting ("The Pink Sheet" Oct. 8, p. 9). A full-scale trial involving 5,000 to 6,000 subjects may be initiated after the pilot study is completed in June 1992. The primary endpoints of the full-scale trial will be coronary heart disease and other cardiovascular morbidity and mortality. The pilot study will monitor those endpoints, but NHLBI noted that the sample size and duration of the study are inadequate to determine the impact of cholesterol-lowering drugs on the endpoints. The CRISP study was discussed at an Oct. 9-10 NHLBI conference on diseases associated with low blood cholesterol. The risk of coronary heart disease has been shown to decrease with a decline in blood cholesterol levels. However, David Jacobs, PhD, University of Minnesota, pointed out that data from observational studies and clinical trials indicate that lowering blood cholesterol may be associated with increased risk of hemorrhagic stroke and noncardiovascular diseases. Jacobs presented a meta-analysis of 18 studies. The analysis showed that in people aged 35-69 who are free of coronary heart disease at baseline, death rates due to noncardiovascular, noncancer causes are elevated at low blood total cholesterol levels and that total cancer deaths are similarly elevated in men. Conference participants noted that a causal relationship between low blood cholesterol and mortality has not been established. Jacobs said a number of plausible biological mechanisms have been proposed to explain the observations of increased disease rates at low blood cholesterol levels. In addition, he said confounding factors may play a role, such as disease conditions and behaviors that may lower blood cholesterol.