Clin Osteol 2005; 10(4): 101-105

Ibandronate - the new bisphosphonate in the treatment of osteoporosis; its position among other bisphosphonates results of clinical trialsNews

V. Vyskočil

In the introduction the author discusses complications of osteoporotic fractures showing that mortality rate of 50-year-old women due to breast cancer is as high as mortality rate due to hip fracture. Osteoporosis, especially in women, is number one cause of hospitalization in the European Union coun­ tries. Very important part of treatment efficacy similar to other chronic conditions is the patient's adherence to the treatment. A crucial contributor to the adherence is an optimum dosage and possibility to extend dosage interval. Ibandronate is a third generation bisphosphonate tested in many trials. A randomized double blind BONE trial in women with postmenopausal osteoporosis suggested that 3 year daily ibandronate 2.5 mg administration resulted in an increase of lumbar spine BMD by 6.5 % and proximal femur BMD by 3.4 %, while in the group with intermittent dosage corresponding BMD increased by 5.7 % and 2.9 %, respectively. BMD in both groups when compared to the control group (1.3 % and -0.7 %, respectively) was signifi­ cantly higher (all p < 0.0001). Relative risk of a new vertebral fracture was reduced by 62 % (daily dosage) and 50 % (intermittent dosage), which is the highest reduction among all bisphosphonates used in osteoporosis treatment. Risk reduction of nonverterbral fractures by 69 % (p = 0.0122) was de­ monstrated in a group of patients with T-score <-3 SD. Ibandronate was therefore the first oral bisphosponate, which demonstrated efficacy even with dosage interval extended beyond one week. Subsequent MOBILE trial investigated the optimum dosage of oral ibandronate in once per month admi­ nistration. Primary outcome of BMD increase was met in all three tested monthly dosages and dosage 150 mg monthly in comparison with dosage 2.5mg daily yielded significantly higher increase of BMD in lumbar spine: 4.9 % vs. 3.9 % with significance level p < 0.001. Ibandronate is one of the bisphosphonates that also has intravenous form. DIVA trial evaluated if intravenous ibandronate 2 mg once every 2 months or 3 mg once every 3 months has efficacy comparable to daily oral dosage 2.5 mg, whose efficacy has been already established in the osteoporosis treat­ ment. Both intravenous dosing regimes after the first year of treatment resulted in significantly (p < 0.001) higher increase of BMD of lumbar spine and proximal femur compared to daily dosage (2 mg/bimonthly: 5.1 % and 2.8 %, respectively; 3 mg/quarterly: 4.8 % and 2.4 %, respectively; 2.5 mg daily: 3.8 % and 1.8 %, respectively). All regimes were comparable one to another regarding CTX suppression and also with other bisphosphonates. Ibandronate has efficacy at least comparable to other aminobisphosphonates and it has an excellent general safety. Extending dosage interval may improve patient's adherence to the treatment and hence also therapeutical results.

Keywords: morbidity, mortality, adher

Published: December 11, 2005  Show citation