The Clinical Characteristics And Efficacy Of Bisphosphonates In Adult Patients With Osteogenesis Imperfecta

Objective: Osteogenesis imperfecta (01) is characterized by low hone mass and recurrent fractures. Adults with OI are often treated with oral or intravenous bisphosphonates (BPs). We investigated the clinical phenotypes of adult OI patients and prospectively compared the efficacy of oral alendronate (ALN) with intravenous zoledronic acid (ZOL) in OI patients.Methods: This 24-month, observational, randomized clinical study included 60 adult patients with OI. We compared the differences in hone mineral density (BMD) and hone turnover bionmrkers between OI adults and healthy subjects. Thereafter, OI patients were randomized at a 2:1 ratio to receive either weekly oral ALN 70 mg or once-yearly infusion of ZOL 5 mg. The efficacy outcomes were changes in BMD, hone turnover biomarkers, and fracture incidence.Results:Adult OI patients had significantly lower BMD and significantly higher cross-linked C-telopeptide of type I collagen (beta-CTX) levels than age-/sex-/BMI-matthed healthy subjects. A total of 52 patients completed the 24-month clinical study. BMD at lumbar spine, femoral neck, and total hip were equivalently elevated in the ALN (10.5, 13.2, and 14.7%, respectively) and ZOL (11.3, 13.7, and 11.7%, respectively; all P>.05) groups. Serum alkaline phosphatase decreased by 30.3% in the ALN group and 37.3% in the ZOL group (P =.12), and beta-CTX decreased by 58.0% in the ALN group and 63.6% in the ZOL group (P=.48). Compared to the prior fracture rates, clinical fracture incidences were decreased in the ALN and ZOL groups (both P<.05).Conclusion: Adults with OI present significantly lower hone mass and higher hone resorption biomarkers than healthy populations. Oral ALN and intravenous ZOL are equally effective at increasing BNID and inhibiting hone turnover in adults with OI. The treatment may reduce fractures in this study, but further efforts are still needed to demonstrate the anti fracture efficacy of BPs.