Effectiveness of Neridronate in the Management of Bone Loss in Patients with Duchenne Muscular Dystrophy: Results from a Pilot Study.

INTRODUCTION

Bone loss is a major issue in patients affected by Duchenne muscular dystrophy (DMD), a rare musculoskeletal disorder, particularly in those treated with glucocorticoids (GCs). We aimed to assess the effectiveness of neridronate in terms of bone mineral density (BMD) changes in this population.

METHODS

We retrospectively reviewed the records of patients affected by DMD receiving GCs referred to our outpatient from 2015 to 2020. All patients were treated with an intramuscular (IM) injection of neridronate (25 mg every month). Bone density was measured at the lumbar spine (LS; L1-L4 tract) using dual-energy x-ray absorptiometry (DXA) (GE Lunar), no more than 4 weeks before (T0) and after 1 year from neridronate treatment (T1).

RESULTS

Eight boys with DMD were included with a mean age at diagnosis of 4.75 ± 2.81 years. Six of them were non-ambulant and two of them had previous low-trauma fractures (a distal femur fracture and a vertebral compression fracture, respectively). All patients were receiving deflazacort [median duration of therapy 11.5 years (interquartile range 2-25)]. At the DXA evaluation (T0), the mean L1-L4 BMD value was 0.716 ± 0.164 g/cm. Six patients (75%) showed an L1-L4 Z-score height-adjusted of less than - 2. The mean age of neridronate initiation was 18.87 ± 6.81 years. All patients were supplemented with calcium carbonate and vitamin D at baseline. After 12 months of treatment (T1), the mean L1-L4 BMD value was 0.685 ± 0.190 g/cm. Seven patients (87.5%) showed an L1-L4 Z-score of less than - 2. Changes in LS BMD and Z-score were not significant between T0 and T1 in our cohort (p = 0.674 and p = 0.208, respectively) as well as among non-ambulant patients with DMD without previous fragility fractures.

CONCLUSIONS

In this study, we reported for the first time that neridronate may slow bone loss in GC-treated patients with DMD at 1-year follow-up.