Once-monthly dosing: An effective step forward

To improve upon the currently suboptimal level of therapeutic adherence with bisphosphonates in postmenopausal osteoporosis, there is a need to examine less-frequently dosed regimens that offer patients greater convenience than weekly dosing.Ibandronate is a potent, nitrogen-containing bisphosphonate specifically developed for administration with long between-dose intervals. It has proven antifracture efficacy when administered orally, daily or intermittently (>2 months dose-free interval) and a safety profile comparable with placebo. A dose-ranging study evaluating a simplified once-monthly ibandronate dosing schedule confirmed the feasibility of the regimen. Significant decreases from baseline in the biochemical markers of bone turnover, serum and urinary C-telopeptide of the α-chain of type 1 collagen (CTX) were observed for all once-monthly doses assessed. An analysis of the area under the effect curve for these two parameters confirmed a dose–response relationship.The MOBILE study was a large (n = 1609), randomized, double-blind, non-inferiority study comparing three doses of monthly oral ibandronate (50 + 50 mg, 100 mg and 150 mg) with daily oral ibandronate (2.5 mg) in women with postmenopausal osteoporosis. Analyses have been completed at the end of 1 and 2 years of treatment. With substantial increases in lumbar spine bone mineral density (BMD; 5.3–6.6%), all of the once-monthly regimens were non-inferior, and, in addition, the 150 mg regimen was superior (P ≤ 0.002) to the daily regimen. Corresponding increases in BMD were also observed at all hip sites. The greatest gains in lumbar spine, and hip BMD were consistently seen with the 150 mg regimen. Considerable reductions in serum CTX were seen with all regimens from 3 months onwards (50.0–66.4%); these reductions were maintained throughout the 2-year period (2 years: 56.1–67.7%). The safety profile of the once-monthly regimens was comparable with the daily regimen throughout the 2 years.Once-monthly ibandronate is an effective and well-tolerated treatment for patients with postmenopausal osteoporosis. Given the recently reported strong patient preference for once-monthly regimens and the impact of patient preference on therapeutic adherence, it is anticipated that once-monthly ibandronate will offer patients an alternative convenient regimen that may improve adherence over weekly bisphosphonates and should enhance outcomes.