WASHINGTON — A monthly dose of oral ibandronate is at least as safe and as effective at increasing bone mineral density as a daily dose, according to data from a study of more than 1,200 postmenopausal women with osteoporosis.
The Monthly Oral Ibandronate in Ladies (MOBILE) study, a multinational randomized, double-blind, phase III study of women aged 55–80 years, will continue for 2 years, Michael Bolognese, M.D., explained in a poster presented at an international symposium sponsored by the National Osteoporosis Foundation. Dr. Bolognese and his colleagues presented their 1-year results at the meeting.
A total of 318 women received a 2.5-mg dose of oral ibandronate (Boniva) daily; another 328 women received a 50/50 mg dose (two 50-mg single doses on 2 consecutive days) monthly; 311 received one 100-mg dose monthly; and 320 received one 150-mg dose monthly.
After 1 year, the increase in BMD at the lumbar spine was 3.9% in the daily group, compared with 4.3%, 4.1%, and 4.9% in the groups receiving, respectively, 50/50 mg, 100 mg, and 150 mg monthly.
Increases in the total hip BMD were 2.2% in the daily group, compared with 2.2%, 2.7%, and 3.1% in the 50/50 mg, and monthly groups, respectively.
Similar increases occurred at the femoral neck and hip trochanter.
In addition, all treatment groups demonstrated significant decreases in serum C-terminal cross-linking telopeptide of type I collagen (CTX), a bone resorption marker that's used to measure the effectiveness of treatment. The 150-mg group showed the most robust response.
“The once-monthly oral ibandronate has a comparable safety profile with the daily, and therefore seems like it should provide an effective, well-tolerated, and practical alternative to daily and weekly oral bisphosphonate,” Dr. Bolognese said in his oral presentation of the data.
The dosage of the newly approved monthly formulation of ibandronate (Boniva) is 150 mg, and it has been shown to have maximal effectiveness when taken 60 minutes before eating meals, said Dr. Bolognese, of Bethesda (Md.) Health Research.
The incidence of adverse events and withdrawal rates were comparable across all treatment groups.
Approximately 70%–80% of the adverse events were gastrointestinal, which remains a concern with bisphosphonate therapy, but the incidence was relatively low and comparable across all treatment groups. In fact, the rate of discontinuation due to upper GI events was lower among patients in the 150-mg group (3.3%), 100-mg group (4.0%), and 50/50-mg group (4.0%), compared with the daily group (5.3%).
Dr. Bolognese is a consultant for Eli Lilly & Co. and Procter & Gamble, and he has received grants or research support from Sanofi-Aventis, Pfizer, Lilly, and Wyeth Pharmaceuticals.