Evidence for safety and efficacy of risedronate in men with osteoporosis over 4 years of treatment: Results from the 2-year, open-label, extension study of a 2-year, randomized, double-blind, placebo-controlled study

Abstract

A 2-year, randomized, double-blind, placebo-controlled study in men with osteoporosis demonstrated that treatment with risedronate 35mg once a week significantly decreased bone turnover markers (BTMs) and increased bone mineral density (BMD). This study was extended to include a 2-year, open-label extension to continue to assess the safety and efficacy of risedronate in men with osteoporosis. In the open-label extension, all patients received risedronate 35mg once a week, and 1000mg elemental calcium and 400 to 500IU vitamin D daily for up to 2 years. The safety of risedronate was evaluated based on adverse events, laboratory data, vital signs, and physical examination results. BMD, BTMs, and the incidence of new vertebral fractures were also assessed. A total of 218 (of 284) patients enrolled in the open-label extension. Risedronate continued to produce significant increases in lumbar spine BMD from baseline (7.87%) in the group of patients who took it for 4 years. Risedronate produced significant increases in lumbar spine BMD from baseline (6.27%) in the former placebo group who took it for 2 years during the open-label extension. Few new vertebral and clinical fractures occurred during the study. There were no significant differences in BTMs between the two groups at months 36 and 48. Incidences of any upper GI adverse events during the extension were low and similar in the two groups; however, the percent of moderate to severe events were higher (8% versus 2%) in the group that received placebo prior to the extension. Safety results continued to show that risedronate was well-tolerated in men with osteoporosis. Patients who received risedronate 35mg once a week for 2years in the open-label extension study showed similar safety and efficacy results compared with those who received risedronate treatment in the first 2 double-blind years of the study. Patients who received risedronate for 4 years in total showed similar safety and efficacy to that observed in women with postmenopausal osteoporosis treated with risedronate for 4 years. (ClinicalTrials.gov Identifier number: NCT00619957).