Context: Odanacatib (ODN), a selective cathepsin-K inhibitor, was found to increase bone mineral density (BMD); the effect on fractures is based on adverse event reports.
Objective: To estimate current effects and predict future effects of ODN on BMD and fractures.
Data sources: Electronic databases (Medline, EMBASE, Cochrane Library), conference proceedings, and bibliographies.
Study selection: Trials that compared ODN 50 mg/wk to placebo for at least 1 year and reported changes in BMD or fractures. Meta-analysis: Two bone outcomes were pooled as independent and as joint outcomes in Bayesian univariate and bivariate random-effects models.
Data synthesis: Of 32 potentially eligible articles, six citations describing four trials (993 patients) were included. ODN for 3 years increased mean BMD at the lumbar spine by 5.0% (95% credible interval [CrI], 2.7, 7.5), total hip by 3.6% (95% CrI, 1.6, 5.9), and femoral neck (FN) by 3.6% (95% CrI, 1.6, 5.7). In a future trial of 3-year duration, the predicted mean increase in BMD, adjusted for the effect on fractures, was 4.9% for lumbar spine (95% CrI, 2.5, 7.4), 3.4% for total hip (95% CrI, 1.7, 5.2), and 3.5% for FN (95% CrI, 1.8, 5.3). After accounting for the effect on FN BMD, ODN for 3 years was associated with a population odds ratio of 0.38 (95% CrI, 0.1, 0.8). In a future trial, the odds ratio was 0.41 (95% CrI, 0.1, 1.1). The probability of benefit on fractures was 96-99%. The estimates remained robust in sensitivity analyses.
Conclusions: Our analyses suggest that ODN will increase BMD and decrease all fractures in the fracture outcome trial; however, direct demonstration of this antifracture efficacy is needed.