30th ASBMR 2008
[M359] Differences in Safety and Efficacy of Generic and Original Branded once weekly Bisphosphonates
Johann Ringe, P. Farahmand.. Klinikum Leverkusen, University of Cologne.
Objective: To compare the changes on bone mineral density (BMD), the effects on persistence and adverse events (AE), in patients treated for postmenopausal osteoporosis with either generic alendronate or with branded Fosamax® or Actonel®, once weekly. Patients and methods: In this retrospective patient chart analysis we reviewed the one year observational treatment results of 186 women (ITT population) with postmenopausal osteoporosis. Patients from our out-patient department having started with once weekly BP therapy between 36 to at least 12 months before this chart review were included in this comparative study with three arms according to their treatment: A: Generic Alendonate 70 mg products, B: Alendronate (Fosamax®) 70 mg and C: Risedronate (Actonel®) 35 mg. All patients received basic therapy with 1200 mg calcium and 800 IU Vit. D per day. Patients'BMD at lumbar spine and total hip was below - 2.5 T-score, with and without prevalent vert. and non-vert. fractures. Results: Analysis of the 186 patients' results shows an average increases in LS-BMD after 12 months of 2.8%. 5.2% and 4.8% for the groups A, B and C resp. The respective mean changes at total hip were 1.5%, 2.9%, and 3.1%. At both sites, the mean increases in BMD were not different between the two groups receiving original BP (B, C) but for both were significantly higher than for the group treated with generic alendronate (A). At 12 months 68% of group A, 84% of B and 94% of C were still on BP-therapy. The persistence of patients treated with generic alendronate was significantly lower as compared to each of the two original BP treated groups. The total number of patients with gastrointestinal AEs were 32, 15 and 9 for A, B and C resp.. Conclusions: Significantly lower increases of lumbar spine and total hip BMD with generic alendronate once weekly as compared to the two branded originals (Fosamax, Actonel) were observed. We do not know the reason for the 40-50% lower BMD increase rates of the generic compounds. At least in part the lower efficacy can be explained by a significantly lower degree of compliance with generic alendronate, which could be related to a higher incidence of GI AE's. Other resaons could be lower bioavailability or potency of generic alendronate.
J.D. Ringe, None.
Date: Monday, September 15, 2008
Session Info: Poster: Osteoporosis Treatment (Clinical): Bisphosphonates (11:30 AM-2:30 PM)
Presentation Time: 11:30 AM