Modeling of serum C-telopeptide levels with daily and monthly oral ibandronate in humans.

A previously validated kinetic-pharmacodynamic model was applied to changes in a marker of bone resorption (serum C-telopeptide cross-links of type I collagen [sCTX]) using data from a large-scale clinical trial of ibandronate (Monthly Oral iBandronate In LadiEs [MOBILE]). The model showed rapid and significant suppression of sCTX compared to baseline with daily and monthly ibandronate, and gradual recovery of sCTX levels between monthly doses. This modeled, post-dose oscillatory pattern of sCTX paralleled significant increases in BMD and was associated with an acceptable safety profile for patients in MOBILE, suggesting that the between-dose recovery of sCTX does not negatively affect the efficacy of once-monthly ibandronate.