Safety and efficacy of teriparatide treatment for severe osteoporosis in patients with Duchenne muscular dystrophy.

Abstract

Despite standard therapy with vitamin D and bisphosphonates (BP), many patientswith Duchenne muscular dystrophy (DMD) continue to sustain fragility fractures due to long-term glucocorticoidtreatment and limited mobility. We aimed toevaluate the safety and efficacy of teriparatide for the treatment of severe osteoporosis in adolescent and young adult patients with DMD. We prospectively treated 6 patients with DMD who had severe osteoporosis with teriparatide 20mcg subcutaneously daily for 1-2years. Inclusion criteria were long-term glucocorticoid therapy, and severe osteoporosis despite treatment with BP, or intolerance to BP. We examined long bone and vertebral fracture outcomes, including vertebral morphometry measures, bone mineral density and content, bone formation markers, safety indices, and adverse events. The mean age at teriparatide start was 17.9years (range 13.9-22.1years). All 6 patients were on daily glucocorticoids (mean ± SD; duration 10.9 ± 2.5years) and 5 were non-ambulatory. Five patients had been treated with BP for 7.9 ± 4.2years. All had vertebral and a history of long bone fragility fractures at baseline. Vertebral heights and Genant fracture grading remained stable. Long bone fracture rate appeared to decrease (from 0.84/year to 0.09/year); one patient sustained a long bone fracture at 6months of treatment. Trajectories for change in bone mineral density and content were not different post- vs. pre-teriparatide. Procollagen type 1 amino-terminal propeptide (P1NP) increased, while laboratory safety indices remained stable and non-concerning. No adverse events were observed. In six patients with DMD treated with teriparatide for severe osteoporosis, we observed stable bone health and modest increases in P1NP, without safety concerns. Further studies are needed to better understand teriparatide efficacy for treatment of osteoporosis in patients with DMD.