Phosphorus is a mineral that is important for healthy bones. Children with XLH have too little phosphorus, leading to weakening of their bones.
At the beginning of Studies 1, 2, and 3, children had rickets of varying severity (as shown by X-rays). Patients were then given CRYSVITA every 2 weeks or continued on conventional therapy for a subset of patients in Study 1, and improvement of their rickets was examined at Weeks 40 and 64.
- *These values are from the Study 1 CRYSVITA Week 40 least squares (LS) mean change of –2.0 (95% confidence interval [CI]: –2.33 to –1.75) and Week 64 LS mean change of –2.2 (95% CI: –2.46 to –2.0). LS mean is a statistic that estimates the mean after adjusting for the effect of other variables in the study, and the 95% CI is a range that includes possible values of the mean reduction in RSS. Note that mean RSS (standard deviation [SD]) at baseline was 3.2 (0.98).
- †These values are from the Study 1 conventional therapy Week 40 LS mean change of –0.7 (95% CI: –0.98 to –0.43) and Week 64 LS mean change of –1.0 (95% CI: –1.31 to –0.72). Note that mean RSS (SD) at baseline was 3.2 (1.14).
All 3 studies of children with XLH found that CRYSVITA led to substantial healing of rickets in a majority of patients
- Study 2: 69% (18/26) of patients achieved substantial healing of rickets at Week 40
- Study 3: 100% (13/13) of patients achieved substantial healing of rickets at Week 40