Monitoring of bone turnover markers does not improve persistence with ibandronate treatment

Objective: To assess if the use of biological marker of bone resorption (CTX) feedback is a mean to improve persistence on monthly oral ibandronate.

Methods: One year prospective multicenter study using a cluster randomisation design with physicians as randomized units into two groups, A and B; in group B, physicians used results of CTX and two standardized messages according to CTX changes from baseline: suboptimal if decrease less than 30% at week 6, positive otherwise. In group A, the follow-up was standard of care. Patients were postmenopausal women, initiating a treatment with ibandronate 150 mg monthly. They were blinded to the study hypotheses and outcome. The outcome was the proportion of patients persistent at 1-year visit.

Results: Eighty-eight physicians were randomized in group A and included 346 patients, 75 in group B included 250 patients. The persistence at 1-year was high and not different between the two groups (75.1 and 74.8% P=0.932). There was no difference in the proportion of persistent patients according to the message delivered in the group of patient with CTX information: 77.4 and 74.8% in patients with a suboptimal or positive message respectively.

Conclusion: This study failed to demonstrate that supporting monitoring of CTX could improve persistence to ibandronate treatment in postmenopausal osteoporosis.

Key messages: Persistence is a strong determinant of anti-osteoporotic treatments efficacy. Monitoring of bone markers is not a mean to improve persistence of an oral bisphosphonate. There is a discrepancy between levels of persistence in clinical studies and real life.