Objectives: To evaluate effects on bone mineral density (BMD), safety, and tolerability of a single daily dose of alendronate (10 mg), administered for 1 year to postmenopausal women with osteoporosis.
Methods: This interim analysis includes the first approximately 20% of patients to complete treatment in a large, placebo-controlled study (the Fosamax International Trial (Fosit)), which enrolled 1908 patients from 34 countries. Patients < or = 85-year-old with osteoporosis (lumbar spinal BMD > or = 2 S.D. below mean for mature premenopausal Caucasian women) were randomly assigned to treatment with alendronate or placebo once daily in the morning; all patients received supplemental calcium (500 mg/day). Dual-Energy X-ray Absorptiometry (DXA) was used to measure BMD in spine and proximal femur.
Results: A total of 297 patients had BMD data available for analysis. Patients treated with alendronate showed progressive increase of BMD during treatment. At 12 months, mean BMD had increased significantly (P < 0.001) at the lumbar spine (5.6%), trochanter (3.6%), and femoral neck (2.6%) in the alendronate group. Increases in BMD were significantly (P < 0.001) greater than in the placebo group at all sites. Among 442 patients assessed for safety, there were no statistically or clinically significant differences between treatment groups in the incidence of adverse events, including upper gastrointestinal adverse events, or laboratory abnormalities.
Conclusions: Results of this multinational study show that oral alendronate, administered as 10 mg once daily for 1 year, is generally well tolerated and produces significant, progressive increases in BMD at the lumbar spine and proximal femur of postmenopausal women with osteoporosis.