Redefine your child’s XLH treatment with CRYSVITA® (burosumab-twza)

Clinical studies of children with XLH have shown that CRYSVITA can help by:

CRYSVITA helped increase and maintain phosphorus levels in the normal range

Increasing and maintaining phosphorus levels in the blood

CRYSVITA helped heal rickets and correct lower limb deformity

Healing rickets and helping to improve leg deformities

CRYSVITA helped increase height

Increasing growth

The benefits and risks of treatment with CRYSVITA were studied in a total of 126 children with XLH

Study 1

  • Number of patients: 61
  • Ages: 1 to 12 years
  • Length of treatment: 64 weeks

Study 1 compared the effects of CRYSVITA with conventional therapy of oral phosphate and active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, or calcifediol).

Study 2

  • Number of patients: 52
  • Ages: 5 to 12 years
  • Length of treatment: 64 weeks

Study 2 identified the optimal dose for CRYSVITA efficacy and safety in children ages 5 to 12 years.

Study 3

  • Number of patients: 13
  • Ages: 1 to 4 years
  • Length of treatment: 64 weeks

Study 3 established the safety and efficacy of CRYSVITA in children ages 1 to 4 years.

CRYSVITA helped increase and maintain phosphorus levels in the normal range
CRYSVITA helped increase and maintain phosphorus levels in the normal range

Serum phosphorus

Phosphorus is a mineral that is important for healthy bones. Children with XLH have too little phosphorus, leading to weakening of their bones. In CRYSVITA clinical studies, children with XLH received CRYSVITA every 2 weeks, and the level of phosphorus in their blood, described as “serum phosphorus,” was measured at Weeks 40 (Studies 1, 2, and 3) and 64 (Studies 1 and 2).

CRYSVITA showed greater improvement in serum phosphorus levels, compared with conventional therapy

In Study 1, 61 children with XLH aged 1 to 12 years were randomly assigned to receive CRYSVITA every 2 weeks or continue with conventional therapy, consisting of oral phosphate and active vitamin D.

Serum phosphorus level (mg/dL)

CRYSVITA increased and sustained serum phosphorus levels, compared with conventional therapy
CRYSVITA increased and sustained serum phosphorus levels, compared with conventional therapy

*Normal serum phosphorus levels for this group of patients ranged from 3.2 to 6.1 milligrams/deciliter (mg/dL). The normal range of serum phosphorus levels varies by age and gender, and ranges may vary by testing laboratory.

All 3 studies of children with XLH showed that CRYSVITA increased and maintained serum phosphorus within the normal range

  • Study 2, serum phosphorus increased from 2.4 mg/dL to 3.3 mg/dL at Week 40 and 3.4 mg/dL at Week 64 with CRYSVITA
  • Study 3, serum phosphorus increased from 2.5 mg/dL to 3.5 mg/dL at Week 40 with CRYSVITA

Remember the treatment goals?

Talk to your child’s doctor about how CRYSVITA can help improve your child’s low phosphorus levels.

CRYSVITA helped heal rickets and correct lower limb deformity
CRYSVITA helped heal rickets and correct lower limb deformity

Rickets

At the beginning of studies of children with XLH aged 1 to 12 years (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.

In these studies, 2 methods were used to assess XLH-related rickets:

  • Thacher Rickets Severity Score (RSS) is a 10-point scale used to assess the changes in the severity of rickets, and reduction in the RSS score corresponds to improvement in rickets severity
  • Radiographic Global Impression of Change (RGI-C) is a 7-point scale used to assess the healing of rickets, and an RGI-C score of +2.0 means substantial healing of rickets

These scoring methods use X-rays of the wrists, legs, and knees and are assigned by independent experts.

CRYSVITA reduced rickets severity, compared with conventional therapy

In Study 1 (61 children with XLH aged 1 to 12 years), 29 children were given CRYSVITA every 2 weeks, and 32 children continued on conventional therapy.

CRYSVITA led to greater reduction in rickets severity, compared with conventional therapy
CRYSVITA led to greater reduction in rickets severity, compared with conventional therapy
  • *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 reduced rickets severity

  • Study 2: 58% reduction in rickets severity at Week 40, and 53% reduction at Week 64 with CRYSVITA
  • Study 3: 59% reduction in rickets severity at Week 40 with CRYSVITA

CRYSVITA led to superior healing of rickets, compared with conventional therapy

In Study 1 at Week 40, 21 out of 29 (72%) patients achieved substantial healing (RGI-C score of +2.0) of their rickets after receiving CRYSVITA every 2 weeks, compared with 2 out of 32 (6%) patients receiving conventional therapy. These results were maintained at Week 64.

72% of patients on CRYSVITA achieved substantial healing of rickets, vs. 6% of patients on conventional therapy
72% of patients on CRYSVITA achieved substantial healing of rickets, vs. 6% of patients on conventional therapy

*Substantial healing is defined as having an RGI-C score of +2.0.

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

CRYSVITA also demonstrated improvements in bone abnormalities of the lower limbs in Studies 1 and 3

Remember the treatment goals?

Talk to your child’s doctor about how CRYSVITA can help heal rickets.

CRYSVITA helped increase height
CRYSVITA helped increase height

Growth

In the study of children aged 1 to 12 years (Study 1), the majority of children with XLH were below the average height for their age. They then received CRYSVITA every 2 weeks or continued on conventional therapy for a total of 64 weeks, and their height was measured again to evaluate changes.

Standing height z-score was used as a measurement of growth. This measurement is standardized according to the reference age and gender of children without XLH, as defined by guidelines from the Centers for Disease Control and Prevention (CDC).

Standing height z-score was used as a measurement of growth. This measurement is standardized according to the reference age and gender of children without XLH, as defined by guidelines from the Centers for Disease Control and Prevention (CDC).

CRYSVITA improved growth, compared with conventional therapy

In Study 1, 29 children with XLH aged 1 to 12 years received CRYSVITA every 2 weeks, and 32 children with XLH continued on conventional therapy.

CRYSVITA improved growth 7% vs 1% on conventional therapy
CRYSVITA improved growth 7% vs 1% on conventional therapy
  • *In Study 1, CRYSVITA treatment for 64 weeks increased standing mean (SD) height z-score from -2.32 (1.17) at baseline to -2.11 (1.11) in the patients who received CRYSVITA every 2 weeks (LS mean [SE] change of +0.17 [0.07], an increase of 7% [0.17 is 7% of 2.32]).
  • †Conventional therapy for 64 weeks increased standing mean (SD) height z-score from -2.05 (0.87) at baseline to -2.03 (0.83) at Week 64 (LS mean [SE] change of +0.02 [0.04], an increase of 1% [0.02 is 1% of 2.05]). The difference between the treatment groups at Week 64 was +0.14 (95% CI: 0.00 to 0.29). LS mean is a statistic that estimates the mean after adjusting for the effect of other variables in the study.

In a previous study of 26 children with XLH aged 5 to 12 years, CRYSVITA helped increase height 11%,* as measured by z-score

  • *In Study 2, CRYSVITA treatment for 64 weeks increased standing mean (SD) height z-score from -1.72 (1.03) at baseline to -1.54 (1.13) in the patients who received CRYSVITA every 2 weeks (LS mean change of +0.19 [95% CI: 0.09 to 0.29], an increase of 11% [0.19 is 11% of 1.72]). 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 for the change in height z-score.

Remember the treatment goals?

Talk to your child’s doctor about how CRYSVITA may help your child’s growth.