Steroid switching in dystrophinopathy treatment: a US chart review of patient characteristics and clinical outcomes.

Aim: To describe reasons for switching from prednisone/prednisolone to deflazacort and associated clinical outcomes among patients with Duchenne and Becker muscular dystrophy (DMD and BMD, respectively) in the USA. Methods: A chart review of patients with DMD (n = 62) or BMD (n = 30) who switched from prednisone to deflazacort (02/2017-12/2018) collected demographic/clinical characteristics, reasons for switching, outcomes and common adverse events. Results: The mean ages at switch were 20.1 (DMD) and 9.2 (BMD) years. The primary physician-reported reasons for switching were 'to slow disease progression' (DMD: 83%, BMD: 79%) and 'tolerability' (67 and 47%). Switching was 'very' or 'somewhat' effective at addressing the primary reasons in 90-95% of patients. Conclusion: Physician-reported outcomes were consistent with deflazacort addressing patients' primary reasons for switching.

Effect of risedronate in a minipig cartilage defect model with allograft.

Cartilage/chondrocyte transplantation is frequently utilized in the repair of focal chondral defects. It has been proposed that failure of subchondral bone maintenance or restoration is a factor contributing to the failure of cartilage-forming transplants. Some studies reveal that the transplant is associated with subchondral bone resorption, often leading to deep pits beneath the presumptive cartilage repair site. Thus, the question is raised as to the utility of agents, such as bisphosphonates, to inhibit bone remodeling at the transplant site. In the present study we show that oral administration (three times weekly) of the bisphosphonate, risedronate, inhibited the subchondral bone loss deep to the cultured allogeneic graft tissue site in attempted repair of surgically created chondral defects in a minipig model. In addition, the graft tissue, characterized by type II collagen, was retained in the majority of treated animals. Untreated minipigs displayed a deep bone resorption pit, beneath the graft region, filled with type I collagen tissue as determined through immunohistochemical staining. This fibrous tissue appeared well integrated with the host tissue in the majority of cases. In the transplanted cartilage region, the overall histological score for tissue quality was significantly (p < 0.05) better for the treated animals which displayed better matrix staining, cell clustering, tidemark integrity, and subchondral bone integrity (p < 0.05 in each category). However, the integration of allograft with host tissue did not always occur completely. Thus, bisphosphonates might be considered in clinical treatment strategies for such procedures.