This website is intended for Healthcare Professionals practicing in the U.S.
Search

The impact of VOXZOGO continues to be studied1,2

Additional preliminary data continue to be collected

VOXZOGO is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).1

The following information is provided to inform healthcare providers on the ongoing assessment and experience of patients in the clinical trial program.

These data are not included in the US Prescribing Information and do not establish a clinical benefit or conclusions on efficacy. The analyses are preliminary and exploratory and should be interpreted cautiously.

Impact on final adult height has not been established and continues to be evaluated as studies are ongoing.

After 3 years, height gain in VOXZOGO-treated and untreated children <2 years old compared with expected gain in average-stature children3

Data Limitations

  • VOXZOGO-treated, untreated, and average-stature children are from different studies; compare with caution as study design and methods may differ.3
  • Effect of VOXZOGO on final adult height not yet established (continually assessing).3
  • Preliminary results not in US label, are descriptive, reflect small samples, may result from chance.1,3

Study Design

  • CANOPY ACH-EXT (Study 208) secondary endpoints include percent height gain in VOXZOGO-treated children after 1, 2, and 3 years of treatment compared to the height gain in matched average-stature children. Similar analysis was conducted with matched untreated children with ACH.3,4†
  • Cohort: Children with ACH aged 3 months to <2 years at VOXZOGO initiation.3
  • Untreated children with ACH: From CLARITY, an external ACH natural history study (N=1341), multiple matched to each treated child at baseline by sex, age, height Z-score, and height.3,5
  • Average-stature children: Height gain derived from CDC reference data for average-stature children, age- and sex-matched to respective treated and untreated ACH groups.3


ACH, achondroplasia; CDC, Centers for Disease Control and Prevention; EXT, extension.

*Adapted from Savarirayan R, et al. ACMG. Toronto, Canada. 2024. Poster P131.3
†Percent height gain vs matched average-stature children: After 1 year, ACH untreated (n=287) 66.73% vs ACH treated (n=32) 80.21%; after 2 years, ACH untreated (n=223) 66.02% vs ACH treated (n=25) 73.68%.3

AGV by age in VOXZOGO-treated children was compared to a separate untreated control group6

Mean (±SD) female AGV by age6*

Mean (±SD) male AGV by age6*

Females
Males

Data Limitations

  • VOXZOGO-treated and untreated groups are from different studies; compare with caution as study design and methods may differ.6
  • Effect of VOXZOGO on final adult height not yet established (continually assessing).6
  • Preliminary results not in the US label, reflect a cross-sectional mix of treatment durations, are descriptive, may result from chance.1,6

Study Design

  • CANOPY ACH-EXT (Study 302) primary endpoints include AGV by age and sex in VOXZOGO-treated children.4,6
  • Cohort: Full analysis set; age 5 to <18 years (N=119).6
  • Mean (SD) treatment duration: 4.0 (0.8) years (min: 1.7 years, max: 6.2 years).6
  • AGV derived for height assessments 12 ± 3 months apart and linked to a specific age integer considering the age at the midpoint of the 12-month interval.6
  • External ACH natural history study (CLARITY): AGV of untreated children with ACH from CLARITY (age- and sex-matched to VOXZOGO-treated children) are plotted.6


ACH, achondroplasia; AGV, annualized growth velocity; EXT, extension; SD, standard deviation.

*Adapted from Savarirayan R, et al. Med. 2025;6(5):100566.6

Body proportionality was measured over 5 years in a subset of VOXZOGO-treated children6

CANOPY ACH-3 (Study 301): After 1 year in the pivotal trial, the secondary endpoint of LS mean change from baseline in upper-to-lower body segment ratio was -0.02 in the placebo group (n=61) and -0.03 in the VOXZOGO group (n=58). The difference in LS mean change from baseline was -0.01 (95% CI: -0.05, 0.02; P=0.5).1,4,7

Mean (±SE) upper-to-lower body segment ratio6*

5-Year Data Limitations

  • VOXZOGO-treated and untreated groups are from different trials; compare with caution as study design and methods may differ.6
  • Effect of VOXZOGO on final adult height and proportionality not yet established (continually assessing).6
  • Preliminary results not in the US label, are descriptive, reflect small samples, may result from chance.1,6

Study Design

  • CANOPY ACH-EXT (Study 302) exploratory endpoints include body proportionality measured by upper-to-lower body segment ratio in VOXZOGO-treated children.4,6,8
  • Cohort: Children with assessments at age <11 years (girls) or <12 years (boys); all children were ≥5 years old at VOXZOGO initiation. Assessments beyond these ages are excluded from analysis.6†
  • CANOPY ACH-OS (Study 901) and CANOPY ACH-3 (Study 301) placebo arm: Upper-to-lower body segment ratio of untreated children with ACH (age-matched to VOXZOGO-treated children) are plotted.4,6,8


ACH, achondroplasia; CI, confidence interval; EXT, extension; LS, least squares; OS, observational= study; SE, standard error.

*Adapted from Savarirayan R, et al. Med. 2025;6(5):100566.6
†In average-stature children, average upper-to-lower body segment ratio is 1.7 at birth and decreases to 1.0 at 10 years old. In ACH, the ratio never reaches 1.0 but still declines from birth up to ~age 10 years in girls and 11 years in boys.6

Backed by the longest clinical trial and postmarketing
experience in achondroplasia.1,2

Health-related quality of life measures were evaluated in VOXZOGO-treated children at 1 and 3 years of treatment9,10

CANOPY ACH-3 (Study 301): After 1 year, changes from baseline in HRQOL of children in the VOXZOGO and placebo groups were evaluated as exploratory endpoints using the QoLISSY questionnaire (developed for children with short stature), where higher scores represent higher HRQOL.4,7,9,10*

  • Self-report version (for children aged 8-18 years) assessed 3 core domains (physical, social, emotional), averaged to create the total score, plus 2 additional domains (coping, beliefs)10
  • Caregiver-report version (for children aged 4-18 years) assessed the same 3 core domains plus 5 additional domains (coping, beliefs, future, effects on parents, treatment); treatment domain not used10

Self-reported QoLISSY scores: Change from baseline at 1 year of treatment (children 8 to <18 years)9,10

Caregiver-reported QoLISSY scores: Change from baseline at 1 year of treatment (children 5 to <18 years)9,10

Self-reported QoLISSY scores: Change from baseline at 3 years of treatment (children aged 8 to <18 years)10,11*†

Caregiver-reported QoLISSY scores: Change from baseline at 3 years of treatment (children aged 5 to <18 years)10,11*†

Child
Caregiver

3-Year Data Limitations

  • No placebo control group, limits interpretation of VOXZOGO treatment effects.10
  • Effect of VOXZOGO on final adult height not yet established (continually assessing).10
  • Preliminary results not in US label, are descriptive, reflect small subgroup sizes.1,10

Study Design

  • CANOPY-EXT (Study 302) secondary endpoints include change from baseline in HRQOL of VOXZOGO-treated children, assessed every 6 months by caregivers (QoLISSY caregiver-report version) and by children with ACH (QoLISSY self-report version).4,10
  • Cohort: VOXZOGO-treated children with ACH aged 5 to <18 years (caregiver-reported) and aged 8 to <18 years 
(self-reported).10
  • Mean (SE) change from baseline of the QoLISSY scores at 3 years of treatment shown for10:
    • All children
    • Subgroup of children that grew the least (change in ACH height Z-score <1)
    • Subgroup of children that grew the most (change in ACH height Z-score ≥1)
  • Untreated ACH referenced Z-scores: Converted from standing height using age- and sex-matched reference data for untreated children with ACH from CLARITY, an external ACH natural history study (N=1,341).5,11


ACH, achondroplasia; EXT, extension; HRQOL, health-related quality of life; QoLISSY, Quality of Life of Short Stature Youth; SE, standard error.

*Validation studies using the QoLISSY questionnaire for children with achondroplasia have been conducted.10,12
†Adapted from Savarirayan R, et al. Genet Med. 2024;26(12):101274.10

The VOXZOGO clinical trial program continues to evaluate multiple endpoints1,2,7,13-15

VOXZOGO is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).1

As clinical trials are ongoing, the impact on final adult height has not been established and continues to be evaluated along with other pre-specified outcome measures.2,7,13-15

*Visit clinicaltrials.gov for the complete list of the trials’ secondary outcome measures (NCT03197766, NCT03424018, NCT03583697, NCT03989947).7,13-15

Learn about your role in ongoing treatment

Your patients and their families may need help maintaining their injection routine.1

Explore Tips for Adherence

References:

  1. VOXZOGO [package insert]. Novato, CA: BioMarin Pharmaceutical Inc; 2024.
  2. ClinicalTrials.gov. Search: Achondroplasia, BioMarin Pharmaceutical. Accessed September 3, 2025. https://www.clinicaltrials.gov/search?cond=Achondroplasia&term=BioMarin%20Pharmaceutical&viewType=Table
  3. Savarirayan R, Wilcox WR, Harmatz P, et al. Persistence of growth-promoting effects in infants and toddlers with achondroplasia: results from a Phase 2 extension study with vosoritide. Annual Clinical Genetics Meeting (ACMG). Toronto, Canada. 2024. Poster. P131.
  4. Data on file [1]. BioMarin Pharmaceutical Inc; 2025.
  5. Hoover-Fong JE, Schulze KJ, Alade AY, et al. Growth in achondroplasia including stature, weight, weight-for-height and head circumference from CLARITY: achondroplasia natural history study-a multi-center retrospective cohort study of achondroplasia in the US. Orphanet J Rare Dis. 2021;16(1):522.
  6. Savarirayan R, Irving M, Wilcox WR, et al. Sustained growth-promoting effects of vosoritide in children with achondroplasia from an ongoing phase 3 extension study. Med. 2025;6(5):100566.
  7. ClinicalTrials.gov. Identifier: NCT03197766. Accessed September 3, 2025. https://www.clinicaltrials.gov/study/NCT03197766
  8. Savarirayan R, Irving M, Wilcox WR, et al. Sustained growth-promoting effects of vosoritide in children with achondroplasia from an ongoing phase 3 extension study. Med. 2025;6(5):100566. Supplementary Appendix.
  9. Data on file [2]. BioMarin Pharmaceutical Inc; 2025.
  10. Savarirayan R, Irving M, Wilcox WR, et al. Persistent growth-promoting effects of vosoritide in children with achondroplasia are accompanied by improvements in physical and social aspects of health-related quality of life. Genet Med. 2024;26(12):101274.
  11. Savarirayan R, Irving M, Wilcox WR, et al. Persistent growth-promoting effects of vosoritide in children with achondroplasia are accompanied by improvements in physical and social aspects of health-related quality of life. Genet Med. 2024;26(12):101274. Supplementary Appendix.
  12. Bloemeke J, Sommer R, Witt S, et al. Cross-cultural selection and validation of instruments to assess patient-reported outcomes in children and adolescents with achondroplasia. Qual Life Res. 2019;28(9):2553-2563.
  13. ClinicalTrials.gov. Identifier: NCT03424018. Accessed September 3, 2025. https://clinicaltrials.gov/study/NCT03424018
  14. ClinicalTrials.gov. Identifier: NCT03583697. Accessed September 3, 2025. https://clinicaltrials.gov/study/NCT03583697
  15. ClinicalTrials.gov. Identifier: NCT03989947. Accessed September 3, 2025. https://clinicaltrials.gov/study/NCT03989947
Contact Us

INDICATION AND IMPORTANT SAFETY INFORMATION

Warnings and Precautions for Risk of Low Blood Pressure
Transient decreases in blood pressure were observed in clinical studies. Patients with significant cardiac or vascular disease and patients on anti-hypertensive medicinal products were excluded from participation in VOXZOGO clinical trials. To reduce the risk of a decrease in blood pressure and associated symptoms (dizziness, fatigue, and/or nausea), patients should be well hydrated, have adequate food intake, and drink approximately 8-10 ounces of fluid in the hour prior to VOXZOGO administration.

In a 52-week, randomized, double-blind, placebo-controlled trial in 121 subjects with achondroplasia, subjects aged from 5.1 to 14.9 years, (Study 1) eight (13%) of 60 patients treated with VOXZOGO had a total of 11 events of transient decrease in blood pressure, compared to 3 (5%) of 61 patients on placebo, over a 52-week treatment period. The median time to onset from injection was 31 (18 to 120) minutes, with resolution within 31 (5 to 90) minutes in VOXZOGO-treated subjects. Two out of 60 (3%) VOXZOGO-treated patients each had one symptomatic episode of decreased blood pressure with vomiting and/or dizziness compared to 0 of 61 (0%) patients on placebo.

Adverse Reactions:
Adverse reactions that occurred in ≥5% of patients treated with VOXZOGO and at a rate greater than that of placebo in the phase 3 study are injection site reactions (including erythema, swelling, urticaria, pain, bruising, pruritus, hemorrhage, discoloration, and induration), vomiting, arthralgia, decrease in blood pressure, gastroenteritis, diarrhea, dizziness, ear pain, influenza, fatigue, seasonal allergy, and dry skin. VOXZOGO-treated patients had an increase in alkaline phosphatase levels (17%), and was noted as a laboratory abnormality.

Injection site reactions: In Study 1, injection site reactions occurred in 51 (85%) subjects receiving VOXZOGO and 50 (82%) subjects receiving placebo over a 52-week period of treatment. Patients receiving VOXZOGO experienced a total of 6983 events of injection site reactions, while patients receiving placebo experienced a total of 1776 events of injection site reactions, over a 52-week period, representing 120.4 events per patient/year exposure and 29.2 events per patient/year exposure, respectively. Two patients in the VOXZOGO arm discontinued treatment due to adverse events of pain and anxiety with injections.

Pediatric Patients 0 to <5 Years:
The safety of VOXZOGO in pediatric patients 0 to <5 years with achondroplasia was evaluated in a 52-week randomized, double-blind, placebo-controlled study (Study 2). In this study, 64 patients from birth to <5 years of age were randomized to receive either a daily vosoritide dose with similar exposure to that characterized to be safe and effective in children with ACH aged ≥5 years old, or placebo. An additional 11 patients received open-label treatment as part of this study. The most common adverse reactions (>10%) reported in pediatric patients 0 to <5 years were injection site reactions (86%) and rash (28%). The overall safety profile of VOXZOGO in pediatric patients 0 to <5 years was similar to that seen in older pediatric patients.

Administration and Monitoring:
VOXZOGO is administered as a daily subcutaneous injection. Prior to use, instruct caregivers on proper preparation and administration of VOXZOGO, and ensure caregivers have demonstrated the ability to perform a subcutaneous injection.

Monitor and assess patient body weight, growth, and physical development regularly every 3-6 months. Adjust dosage according to the patient’s actual body weight. Permanently discontinue treatment with VOXZOGO upon confirmation of no further growth potential, indicated by closure of epiphyses.

Special Populations:

  • There are no available data on the use of VOXZOGO in pregnant women, or data on the presence of VOXZOGO in human milk, the effects on the breastfed infant, or the effects on milk production.
  • The influence of renal impairment on the pharmacokinetics of VOXZOGO has not been evaluated. No dosage adjustment is needed for patients with eGFR ≥60 mL/min/1.73 m2. VOXZOGO is not recommended for patients with eGFR <60 mL/min/1.73 m2.

You may report side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. You may also report side effects to BioMarin at 1-866-906-6100.

Please see additional safety information in the full Prescribing Information.

VOXZOGO® (vosoritide) is indicated to increase linear growth in pediatric patients with achondroplasia and open growth plates.

  • This indication is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).