[Results of international clinical trials with raloxifene]

A new drug class called Selective Estrogen Receptor Modulators (SERM) could combine ideal properties for a product designed for menopausal women. The most widely studied member of this class is raloxifene which is currently marketed in several countries for the prevention of osteoporosis in menopaused women. This product is a nonsteroidal derivative of benzothiophene which, like estrogens, has a preventive effect against bone loss involving the spine and peripheral skeleton and a cholesterol lowering effect, both in the ovariectomized rat and in menopausal women. Unlike estrogens, raloxifene does not stimulate breast or uterine tissue. These interesting properties make raloxifene a possible preventive treatment for osteoporosis and other menopause-related risks for menopausal women of all ages. Multicenter studies have been conducted in recently menopausal women who received either raloxifene at the doses of 30, 60, or 150 mg/day or a placebo in a randomized protocol. All subjects were also given calcium supplementation. Bone density was measured twice a year for 36 months by dual X-rays absorptiometry and showed a significant decrease at all sites in the placebo group while there was a significant increase in the spine, the hip and the overall skeleton for all three raloxifen groups. After 24 months of treatment, mean increase over placebo was 2.4% for 60 mg raloxifene measured on the spine and total hip and 2% for the overall skeleton. Markers of bone formation (serum osteocalcin and bone alkaline phasphatase) and resorption (urinary CrossLaps) decreased significantly reaching, after 3 to 6 months of treatment, the levels observed in non menopausal women. In addition, total serum cholesterol as well as LDL-cholesterol decreased significantly in a dose-dependent fashion in all groups treated with raloxifene. Serum HDL-cholesterol and triglycerides did not very significantly during treatment. Hot flashes were the most frequently observed undesirable effect, at a frequency slightly higher in the raloxifene group (25%) than in the placebo group (18%). This undesirable effect was of low intensity and generally occurred during the first months of treatment. It did not cause a higher drop out rate (raloxifen 1.5%; placebo 2.1%). The preliminary data at two years follow-up suggest that raloxifene is not associated with an increased risk of breast cancer. In conclusion, raloxifene is a particularly interesting drug for menopausal women showing very promising efficacy and clinical tolerance.