Patients with glucocorticoid dependent Duchenne Muscular Dystrophy (DMD) have increased fracture risk and reduced bone mineral density (BMD), often precipitating mobility loss.To investigate use of Zoledronic acid (ZA) in DMD in improving BMD.Two arm, parallel, randomised controlled trial.Paediatric hospitals across Australia and New Zealand.Sixty-two (31 per arm) boys with glucocorticoid dependent DMD between 6-16 years.Five ZA infusions (0.025mg/kg at months 0,3, 0.05mg/kg at months 6, 12 and 18), plus calcium and vitamin D, compared with calcium and vitamin D alone.Change in lumbar spine (LS) BMD raw and Z-score by dual energy absorptiometry x-ray (DXA) at 12 and 24 months, secondary outcomes assessing mobility, fracture incidence, bone turnover, pQCT and pain scores.At 12 and 24 months, mean difference in changes of LSBMD Z-score from baseline was 1.2 SD (95% CI: 0.9-1.5), higher by 19.3% (14.6-24.0) and 1.4 SD (0.9-1.9), higher by 26.0% (17.4-34.5) in ZA compared to control arms respectively (both p < 0.001). Five controls developed Genant 3 vertebral fractures, 0 in the ZA arm. Mobility, pain and bone turnover markers were similar between arms at 12 and 24 months Trabecular BMC and vBMD pQCT at radius and tibia were greater at 12 months in the ZA cohort compared to control; difference remaining at 24 months for radius.ZA improved BMD in glucocorticoid dependent DMD boys. Whilst the small cohort precluded demonstrable fracture benefit, improved BMD might reduce incident vertebral fracture.
Margaret Zacharin, Angelina Lim, James Gryllakis, Aris Siafarikas, Craig Jefferies, Julie Briody, Natasha Heather, Janne Pitkin, Jaiman Emmanuel, Katherine J Lee, Xiaofang Wang, Peter J Simm, Craig F Munns