Learn how
CRYSVITA®
(burosumab-twza)

MAY HELP
YOUR CHILD

Cera, living with XLH

Clinical studies of children with X-linked hypophosphatemia (XLH) have shown that CRYSVITA can help by:

Results of phosphorus levels in children icon

Increasing and
maintaining
phosphorus levels in
the blood

Results of healing rickets in children icon

Healing rickets and
helping to improve
leg abnormalities

Results of increasing growth in children icon

Increasing
growth

The risks and benefits of
CRYSVITA
treatment were studied
in 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 CRYSVITA dose for efficacy and safety in children aged 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 aged 1 to 4 years.

Results of phosphorus levels in children icon
Results of phosphorus levels in children icon

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.

How serum phosphorus was recorded

Across the 3 CRYSVITA clinical studies, children with XLH received CRYSVITA every 2 weeks, and the amount of phosphorus in their blood, called 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.

Study 1: CRYSVITA® helped to increase phosphorus levels graph resultsStudy 1: CRYSVITA® helped to increase phosphorus levels graph results

*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 sex, 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
Results of healing rickets in children icon
Results of healing rickets in children icon

RICKETS

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.

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 helped reduce rickets severity when compared to conventional therapy

In Study 1, 29 children received CRYSVITA every 2 weeks, and 32 children continued conventional therapy.

Study 1: CRYSVITA® helped to reduce rickets severity graph resultsStudy 1: CRYSVITA® helped to reduce rickets severity graph results
  • *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.

Study 1: CRYSVITA® helped heal rickets infographic resultsStudy 1: CRYSVITA® helped heal rickets infographic results

*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*

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

Results of increasing growth in children icon
Results of increasing growth in children icon

GROWTH

In Study 1, the majority of children with XLH were below the average height for their age

  • After receiving CRYSVITA every 2 weeks or continuing conventional therapy for a total of 64 weeks, 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 sex of children without XLH, as defined by guidelines from the Centers for Disease Control and Prevention (CDC).

CRYSVITA significantly increased height compared with conventional therapy

In Study 1, 29 children with XLH received CRYSVITA every 2 weeks and 32 children with XLH continued conventional therapy.

Study 1: CRYSVITA® helped to increase height Z-score graph resultsStudy 1: CRYSVITA® helped to increase height Z-score graph results
  • *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 was statistically significant at Week 64 (+0.14 [95% CI: 0.00 to 0.29], P=0.0490). LS mean is a statistic that estimates the mean after adjusting for the effect of other variables in the study.

In Study 2 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.