Comparison of the effects of once-monthly versus once-daily risedronate in postmenopausal osteoporosis: a phase II, 6-month, multicenter, randomized, double-blind, active-controlled, dose-ranging study.

BACKGROUND: Risedronate 5 mg/d is approved by the US Food and Drug Administration for the treatment and prevention of postmenopausal osteoporosis. Once-monthly dosing options might increase treatment compliance and persistence. OBJECTIVE: The aim of this study was to compare the tolerability and efficacy of 3 once-monthly risedronate dosing regimens with those of risedronate 5 mg/d. METHODS: This Phase II, 6-month, randomized, double-blind, active-controlled, dose-ranging study was conducted at 13 clinical research centers and hospitals in Croatia, Poland, Canada, and the United States between April 2004 and June 2005. Post-menopausal women aged 50 to 85 years with a lumbar spine T-score <-2.0 were randomly assigned to 1 of 4 treatment groups: risedronate 100, 150, or 200 mg/mo or 5 mg/d (active control), administered PO for 6 months. Evaluation of tolerability, the primary study objective, was based on adverse-event (AE) profiles and clinical laboratory values. Efficacy evaluation, a secondary objective, was a noninferiority comparison of the changes from baseline in bone mineral density (BMD) and bone turnover markers (BTMs). RESULTS: Of 370 patients randomized (91, 88, 88, and 103 patients in the risedronate 100-, 150-, and 200-mg/mo and 5-mg/d groups, respectively), 57% were > or =65 years of age and 99% were white; 316 patients (85.4%) completed the study. Completion rates were not significantly different across treatment groups, nor were reasons for discontinuation. Between-group differences in the incidences of treatment-emergent AEs, serious AEs, and upper gastrointestinal (GI) AEs were nonsignificant. Overall, 6 (7%), 14 (16%), 6 (7%), and 9 patients (9%) withdrew because of AEs in the 100-, 150-, and 200-mg/mo and 5 mg/d groups, respectively. GI disorders were the AEs that most frequently led to study withdrawal (5 [5.5%], 7 [8.0%], 4 [4.5%], and 6 [5.8%]). No trends were observed in the nature or frequency of other AEs causing withdrawal. All serious AEs were considered unrelated to treatment, with the exception of erosive esophagitis in 1 patient (1%) who received the 5-mg/d dose. Mean percentage increases in BMD were 2.10%, 2.99%, and 3.38% with risedronate 100, 150, and 200 mg/mo, respectively, versus 3.05% with 5 mg/d. At the 2 higher monthly doses, the changes from baseline in BMD were not significantly different from those in the 5-mg/d group. Mean BTM values were decreased significantly from baseline in all 4 treatment groups, and the changes from baseline at 6 months at the 2 higher monthly doses were not significantly different from those at 5 mg/d. CONCLUSIONS: Overall, in this study, the safety profiles of risedronate 100, 150, and 200 mg/mo were not different from that of risedronate 5 mg/d. Changes in efficacy measures in the monthly treatment groups were considered dose related and were not significantly different between the 5-mg/d group and the 150- and 200-mg/mo groups; similarity was greatest with 150 mg/mo.

Efficacy and safety of risedronate 150 mg once a month in the treatment of postmenopausal osteoporosis.

INTRODUCTION: Risedronate has been shown to be effective in the treatment of postmenopausal osteoporosis when given orally in daily or weekly doses or on 2 consecutive days per month. This randomized, double-blind, multi-center study was designed to assess the efficacy and safety of a single 150 mg risedronate once-a-month oral dose compared with the 5 mg daily regimen. METHODS: Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg daily (n=642) or 150 mg once a month (followed by daily placebo) (n=650) in a double-blind fashion for 2 years. Study drug was taken on an empty stomach at least 30 min before breakfast. Bone mineral density, bone turnover markers, fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine bone mineral density after 1 year. RESULTS: 538 patients in the daily group (83.8%) and 556 patients in the once-a-month group (85.5%) completed 1 year. The mean percent change in lumbar spine bone mineral density was 3.4% (95% confidence interval, 3.03% to 3.82%) in the daily group and 3.5% (95% confidence interval, 3.15% to 3.93%) in the once-a-month group. The difference between groups was -0.1% (95% confidence interval, -0.51% to 0.27%). The once-a-month regimen was determined to be non-inferior to the daily regimen based on prospectively defined criteria. The mean percent changes in bone mineral density at sites in the hip (total proximal femur, femoral neck, femoral trochanter) were also similar in both dose groups, as were the changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the 2 treatment groups. Both regimens were well tolerated; the percent of patients who withdrew from treatment as a result of an adverse event was 9.5% in the daily group and 8.6% in the once-a-month group. CONCLUSIONS: Risedronate 150 mg once a month is similar in efficacy and safety to daily dosing and may provide an alternative for patients who prefer once-a-month oral dosing.

Monthly dosing with risedronate 50 mg on three consecutive days a month compared with daily dosing with risedronate 5 mg: a 6-month pilot study.

OBJECTIVE: Risedronate 5 mg daily significantly reduces the incidence of vertebral and non-vertebral osteoporotic fractures in postmenopausal women. We compared the efficacy and tolerability of risedronate 50 mg administered on 3 consecutive days per month, with and without a loading dose, with those of risedronate 5 mg daily in a randomized, double-blind study. METHODS: Subjects were postmenopausal women 65-80 years old with low bone mineral density (BMD) (T-score < or = -2). Subjects received risedronate 5 mg daily for 6 months (n = 48), risedronate 150 mg (50-mg doses on 3 consecutive days) monthly for 6 months (n = 50), or a loading dose of risedronate 15 mg daily for 1 month followed by 150 mg (50-mg doses on 3 consecutive days) monthly for 5 months (n = 52). RESULTS: Within 1 week, statistically significant reductions in urine N-telopeptide, the primary efficacy measure, were observed in all three groups. After 6 months, the least squares (LS) mean differences (95% confidence intervals [CI]) from the change in the 5 mg daily group (-39.88) were -3.54% (-15.71; 8.64) for the 150 mg monthly and -2.02% (-14.13;10.10) for the loading dose + 150 mg monthly groups. Mean percent changes in serum alpha-C-telopeptide, bone-specific alkaline phosphatase, and BMD, secondary efficacy measures, after 6 months were also similar for the three groups. The LS mean differences (95% CI) from the mean percent change in BMD in the 5 mg daily group (3.22%) were 0.20 (-1.15; 1.55) for the 150 mg monthly and -0.58 (-1.93; 0.76) for the loading dose + 150 mg monthly groups. The safety profile of the monthly regimens was similar to that of the 5 mg daily regimen and consistent with product labeling. CONCLUSIONS: A monthly regimen of risedronate 50 mg on 3 consecutive days per month was similar to risedronate 5 mg daily with respect to its effect in suppressing bone turnover and increasing BMD and its safety profile in women with postmenopausal osteoporosis. This study was not powered to be a confirmatory trial for non-inferiority; therefore, additional study is needed.

Safety and efficacy of risedronate in patients with age-related reduced renal function as estimated by the Cockcroft and Gault method: a pooled analysis of nine clinical trials.

UNLABELLED: The incidences of osteoporosis and renal insufficiency increase with age. We studied the influence of renal function on the safety and efficacy of risedronate 5 mg daily in osteoporotic women. Risedronate was safe and effective in osteoporotic women with mild, moderate, or severe age-related renal impairment. INTRODUCTION: The incidences of both osteoporosis and renal insufficiency increase with age; thus, the effect of renal impairment on the safety and efficacy of osteoporosis treatments is a clinical concern. Risedronate is a pyridinyl bisphosphonate well established as safe and effective in the treatment and prevention of osteoporosis. Currently, there is little available information about the effect of bisphosphonate treatment in patients with renal insufficiency. This retrospective analysis was conducted to study the influence of renal function on the safety and efficacy of risedronate in a population of osteoporotic women. MATERIALS AND METHODS: Combined data from nine randomized, double-blind, placebo-controlled phase III risedronate trials were analyzed. The patients in these studies had no markedly abnormal laboratory parameters that were considered clinically significant and no evidence of significant disease. This analysis included patients who received placebo (n = 4,500) or risedronate 5 mg (n = 4,496) for up to 3 years (average duration of exposure, 2 years) and who had renal impairment (creatinine clearance [CrCl] < 80 ml/min). CrCl was estimated by the Cockcroft and Gault method, based on age, weight, and serum creatinine. Patients were categorized as having mild (CrCl >or=50 to <80 ml/min), moderate (CrCl >or=30 to <50 ml/min), or severe (CrCl < 30 ml/min) renal impairment. RESULTS: Of the patients studied, renal impairment at baseline was mild in 48% (mean [range] serum creatinine, 0.9 [0.4-1.6] mg/dl), moderate in 45% (1.1 [0.6-1.9] mg/dl), and severe in 7% (1.3 [0.7-2.7] mg/dl). In both the placebo and risedronate treatment groups, the patients with the most severe renal impairment were older and had more severe osteoporosis. The incidences of overall adverse events and of renal function-related adverse events were similar in the placebo and risedronate 5 mg groups regardless of renal function. Furthermore, evaluation of changes from baseline in serum creatinine revealed no difference in renal function between the placebo and risedronate 5 mg groups in any of the renal impairment subgroups at any time-point. In all three subgroups, risedronate effectively preserved BMD and reduced the incidence of vertebral fractures. CONCLUSIONS: These findings show that risedronate is safe and effective in osteoporotic women with age-related mild, moderate, or severe renal impairment.