Objectives: To study the efficacy and safety of once-monthly oral ibandronate in the prevention of glucocorticoid (GC)-induced osteoporosis (GIOP) in postmenopausal women with inflammatory rheumatic diseases.
Method: A randomized, double-blind, placebo-controlled, parallel-group study of 140 postmenopausal women was conducted. At baseline, the mean lumbar spine (LS) (L1-L4) bone mineral density (BMD) was normal or osteopaenic (T-score ≥ -2.0) and the patients were receiving treatment with 5-15 mg/day of prednisone equivalent. Patients were randomized 1:1 to receive either monthly oral ibandronate 150 mg or placebo for 12 months. All patients received vitamin D and calcium supplements. The primary endpoint was the relative change in mean LS BMD from baseline to 12 months.
Results: Mean LS BMD increased significantly by 2.6% and 3.2% from baseline to 6 and 12 months with ibandronate compared to 0.3% and -0.1% with placebo, respectively (p < 0.001). Comparable significant mean increases were also found in trochanter, femoral neck and total hip BMDs at 12 months. Reductions in the serum levels of bone turnover markers C-terminal telopeptide of type I collagen (sCTX), N-terminal propeptide of type I procollagen (P1NP), and tartrate-resistant acid phosphatase (TRACP) were significantly more marked in the ibandronate group than in the placebo group at 1, 6, and 12 months. Adverse events (AEs) were reported at a similar frequency in both groups. A higher proportion of serious AEs (SAEs) were reported in the ibandronate group without emergence of any single SAE.
Conclusions: Once-monthly oral ibandronate provides a significant increase in LS and total hip BMD with an acceptable safety profile in postmenopausal women treated with low-dose GCs for inflammatory rheumatic diseases.