BioMarin Presents New Data on the Positive Impact of Early Treatment With VOXZOGO® (vosoritide) on Proportionality and Arm Span in Children with Achondroplasia at the 2026 American College of Medical Genetics and Genomics (ACMG) Annual Clinical Genetics Meeting

March 12, 2026

SAN RAFAEL, Calif., March 12, 2026 /PRNewswire/ — BioMarin Pharmaceutical Inc. (Nasdaq: BMRN) today announced positive new data from studies of VOXZOGO^® (vosoritide) in children with achondroplasia in ongoing clinical trials and real-world studies. The latest findings reinforce the importance of early treatment and the well-known, established efficacy and safety of VOXZOGO. The data will be presented at the 2026 American College of Medical Genetics and Genomics (ACMG) Annual Clinical Genetics Meeting in Baltimore.

Early Treatment, Maximum Impact in Children Who Start Treatment Before Age 2

New data will be presented from a study of children who started VOXZOGO before age 2, which showed that treatment was associated with durable, multi-year growth improvements, including body proportionality and arm span compared to untreated children, as well as improvements in height over time.

For proportionality, measured by change from baseline in upper‑to‑lower body segment ratio (ULBR), the least squares mean difference versus untreated children showed improvement by year one in children initiating VOXZOGO under age 2, and this difference continued to improve each year through year four. Specifically, the least squares mean difference versus untreated children in year one was −0.33 (p=0.0005) in children initiating VOXZOGO under age 6 months, and −0.10 (p=0.042) in those initiating treatment with VOXZOGO under 2 years; by year four, this trend continued, with a least squares mean difference versus untreated children of -0.53 (p<0.0001) in children initiating VOXZOGO under age 6 months, and -0.23 (p=0.0003) in those who initiated treatment with VOXZOGO under 2 years.

Additional analyses further emphasize that these children showed durable improvements in height while maintaining stable arm‑to‑height ratios, consistent with arm span improvements compared to untreated children, which is particularly relevant in early life. Researchers also saw significant improvements in body mass index (BMI) in children who initiated treatment when compared to untreated children.

“It is encouraging to see increasing data on outcomes beyond height, including measures such as body proportionality and arm span,” said Michael Hughes, Chair of the Biotech Industry Liaison Committee at Little People of America (LPA). “BioMarin’s continued efforts on studying these outcomes, along with findings suggesting improvements in these areas with treatments such as VOXZOGO, help expand our understanding of skeletal development in achondroplasia and inform conversations between families and their healthcare providers.”

With regard to growth measures, among more than 20 children who began treatment between 0.5 to <2 years of age, average additional height gain after four years of treatment was 4.7 cm (p=0.0002), and an average height Z‑score improvement of 0.8 (p=0.0008) was observed compared to untreated children in the same reference population, supporting sustained improvement in height relative to expected growth rates in children with achondroplasia.

“Today’s results reaffirm what treating physicians have consistently told us and what was published in consensus clinical guidelines: the earlier you treat with VOXZOGO, the greater the likelihood of maximizing the benefit seen with this treatment, not just in height but more importantly, other measures of health including proportionality,” said Greg Friberg, M.D., Executive Vice President and Chief Research & Development Officer at BioMarin. “As the only approved medicine for children with achondroplasia starting at birth, VOXZOGO provides physicians a medicine that we know is effective and has a positive safety profile in the youngest children with achondroplasia, where there is the greatest opportunity to make an impact on the overall health of these children.”

Global Real-World Evidence from Europe, Japan and the U.S.

To date, more than 5,000 infants and children across more than 50 countries have received VOXZOGO. At ACMG, researchers will present findings on real-world evidence highlighting the impact of VOXZOGO in children who were treated in Japan, Europe and the U.S.

Children with achondroplasia in Japan under the age of 2 years who received VOXZOGO demonstrated good adherence to treatment and robust height improvements, including a mean change from baseline at 12 months of 9.91 cm, and a mean height change from baseline at 24 months of 15.62 cm. In a real-world study out of France, children who received VOXZOGO for 36 months demonstrated sustained growth benefits, including a mean height gain of 16.7 cm with a 0.75 increase in height Z-score compared to the average population.

These findings were supported by interim results from the Acorn Study, a multicenter, post-authorization safety study enrolling participants throughout Europe with an observation period of 10 years from enrollment of the first participant. In addition, the real-world benefit of VOXZOGO was also demonstrated in the VIrtual STudy in Achondroplasia (VISTA) in the U.S., where effectiveness data were consistent with clinical trial data, and trends in improvements in physical functioning underscored the importance of early treatment initiation to maximize clinical benefit.

Below are BioMarin’s key poster presentations at ACMG, with all times listed in Eastern Daylight Time:

Skeletal Conditions

Experimental FGFR3 Saturation Mutagenesis and Big-Data Integration Identify 20 Novel Pathogenic Variants in Hypochondroplasia
Poster #P107
Thursday, March 12, 10:30 – 11:30 a.m.

Long-Term Vosoritide Improves Bone Mineral Density and Bone Content in Children With Achondroplasia: Results From Quantitative Computed Tomography Analyses
Poster #P271
Thursday, March 12, 10:30 – 11:30 a.m.

Real-World Healthcare Utilization, Effectiveness, Health-Related Quality of Life, and Adherence to Vosoritide in Children with Achondroplasia in the United States
Poster #P209
Thursday, March 12, 10:30 – 11:30 a.m.

Early Start, Maximum Impact: Long-Term Trial Data Supporting Cumulative Clinical Benefit in Children Who Initiated Vosoritide <2 Years Old
Poster #P174
Friday, March 13, 10:30 – 11:30 a.m.

Effectiveness of Vosoritide in Children With Achondroplasia Starting Treatment Aged <2 Years: Interim Results From a Japanese Real-World Study
Poster #P216
Friday, March 13, 10:30 – 11:30 a.m.

From Early Access to Routine Care: Prospective Real-World Follow-Up of Vosoritide in Achondroplasia in France
Poster #P222
Friday, March 13, 10:30 – 11:30 a.m.

Interim Real-World Results From the Acorn Study: Long-Term Safety and Growth Outcomes of Vosoritide in Children With Achondroplasia
Poster #P138
Friday, March 13, 10:30 – 11:30 a.m.

Enzyme Therapies

Updating the Spectrum of ARSB Mutations Suspected of Causing Maroteaux-Lamy (MPS VI) to Enable Genetic Prevalence Estimation and Improve Diagnostics
Poster #P319
Thursday, March 12, 10:30 – 11:30 a.m.

Updating the Spectrum of GALNS Mutations Suspected of Causing Morquio A (MPS IVA) to Enable Genetic Prevalence Estimation and Improve Diagnosis
Poster #P245
Thursday, March 12, 10:30 – 11:30 a.m.

Updating the Spectrum of TPP1 Mutations Suspected of Causing CLN2 (Batten Disease) to Enable Earlier Genetic Testing and Inform Prevalence
Poster #P219
Thursday, March 12, 10:30 – 11:30 a.m.

About Achondroplasia

Achondroplasia, the most common form of skeletal dysplasia leading to disproportionate short stature in humans, is characterized by slowing of endochondral ossification, which results in disproportionate short stature and disordered architecture in the long bones, spine, face and base of the skull. This condition is caused by a change in the FGFR3 gene, a negative regulator of bone growth.

More than 80% of children with achondroplasia have parents of average stature and have the condition as the result of a spontaneous gene mutation. The worldwide incidence rate of achondroplasia is about one in 25,000 live births. VOXZOGO is being tested in children whose growth plates are still “open,” typically those under 18 years of age. Approximately 25% of people with achondroplasia fall into this category.

For more information about our clinical trials in achondroplasia, hypochondroplasia and other skeletal conditions, please visit clinicaltrials.biomarin.com.

About VOXZOGO

In children with achondroplasia, endochondral bone growth, an essential process by which bone tissue is created, is negatively regulated due to a gain of function mutation in FGFR3. VOXZOGO, a C-type natriuretic peptide (CNP) analog, acts as a positive regulator of the signaling pathway downstream of FGFR3 to promote endochondral bone growth.

VOXZOGO is the only approved medicine to support the growth of children with achondroplasia starting from birth, with international consensus guidelines recommending initiation of VOXZOGO as early as possible. First approved in 2021, VOXZOGO has helped more than 5,000 infants and children in more than 50 countries. Through our ongoing studies, BioMarin continues to evaluate VOXZOGO on key clinical endpoints relevant for achondroplasia patients, such as arm span, tibial bowing (leg bowing), body proportionality, spinal morphology (including spinal stenosis) and quality of life measures.

VOXZOGO is approved in the U.S., Japan and Australia to increase linear growth in children of all ages with achondroplasia with open epiphyses, and VOXZOGO is indicated in the EU for the treatment of achondroplasia in children 4 months of age and older whose epiphyses are not closed, as confirmed by appropriate genetic testing. In the U.S., this indication is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trial(s). To fulfill this post-marketing requirement, BioMarin intends to use the ongoing open-label extension studies compared to available natural history.

Patient Support Accessing VOXZOGO

BioMarin’s robust support services have ensured a seamless treatment experience, spearheaded by Clinical Coordinators, who have conducted hundreds of trainings for families with achondroplasia since approval. BioMarin provides resources to support families navigating achondroplasia, including a caregiver mentorship program that connects parents with other caregivers, and a U.S. doctor directory that helps families and healthcare professionals identify clinicians experienced in achondroplasia care.

To reach a BioMarin RareConnections^® Case Manager, please call, toll-free, 1-833-VOXZOGO (1-833-869-9646) or e-mail VOXZOGOSupport@biomarin-rareconnections.com. For more information about VOXZOGO, please visit www.voxzogo.com. For additional information regarding this product, please contact BioMarin Medical Information at medinfo@bmrn.com.

VOXZOGO U.S. Important Safety Information

What is VOXZOGO used for?

• VOXZOGO is a prescription medicine used to increase linear growth in children with achondroplasia and open growth plates (epiphyses).
• VOXZOGO is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.

What is the most important safety information about VOXZOGO?

• VOXZOGO may cause serious side effects including a temporary decrease in blood pressure in some patients. To reduce the risk of a decrease in blood pressure and associated symptoms (dizziness, feeling tired, or nausea), patients should eat a meal and drink 8 to 10 ounces of fluid within 1 hour before receiving VOXZOGO.

What are the most common side effects of VOXZOGO?

• The most common side effects of VOXZOGO include injection site reactions (including redness, itching, swelling, bruising, rash, hives, and injection site pain), high levels of blood alkaline phosphatase shown in blood tests, vomiting, joint pain, decreased blood pressure, and stomachache. These are not all the possible side effects of VOXZOGO. Ask your healthcare provider for medical advice about side effects, and about any side effects that bother the patient or that do not go away.

How is VOXZOGO taken?

• VOXZOGO is taken daily as an injection given under the skin, administered by a caregiver after a healthcare provider determines the caregiver is able to administer VOXZOGO. Do not try to inject VOXZOGO until you have been shown the right way by your healthcare provider. VOXZOGO is supplied with Instructions for Use that describe the steps for preparing, injecting, and disposing VOXZOGO. Caregivers should review the Instructions for Use for guidance and any time they receive a refill of VOXZOGO in case any changes have been made.
• Inject VOXZOGO 1 time every day, at about the same time each day. If a dose of VOXZOGO is missed, it can be given within 12 hours from the missed dose. After 12 hours, skip the missed dose and administer the next daily dose as usual.
• The dose of VOXZOGO is based on body weight. Your healthcare provider will adjust the dose based on changes in weight following regular check-ups.
• Your healthcare provider will monitor the patient’s growth and tell you when to stop taking VOXZOGO if they determine the patient is no longer able to grow. Stop administering VOXZOGO if instructed by your healthcare provider.

What should you tell the doctor before or during taking VOXZOGO?

• Tell your doctor about all of the patient’s medical conditions including
  • If the patient has heart disease (cardiac or vascular disease), or if the patient is on blood pressure medicine (anti-hypertensive medicine).
  • If the patient has kidney problems or renal impairment.
  • If the patient is pregnant or plans to become pregnant. It is not known if VOXZOGO will harm the unborn baby.
  • If the patient is breastfeeding or plans to breastfeed. It is not known if VOXZOGO passes into breast milk.
• Tell your doctor about all of the medicines the patient takes, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

You may report side effects to BioMarin at 1-866-906-6100. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

Please see additional safety information in the full Prescribing Information and Patient Information.

About BioMarin

BioMarin is a leading, global rare disease biotechnology company focused on delivering medicines for people living with genetically defined conditions. Founded in 1997, the San Rafael, California-based company has a proven track record of innovation, with eight commercial therapies and a strong clinical and preclinical pipeline. Using a distinctive approach to drug discovery and development, BioMarin seeks to unleash the full potential of genetic science by pursuing category-defining medicines that have a profound impact on patients. To learn more, please visit www.biomarin.com.

Forward-Looking Statements

This press release contains forward-looking statements about the business prospects of BioMarin Pharmaceutical Inc. (BioMarin), including without limitation, statements about: the data to be presented at the 2026 American College of Medical Genetics and Genomics Annual Clinical Genetics Meeting, including the key poster presentations; the development of BioMarin’s VOXZOGO program; the safety profile and potential benefits of VOXZOGO for children with achondroplasia, including the expectation that earlier treatment should lead to potentially greater benefits; and the continued clinical development of VOXZOGO. These forward-looking statements are predictions and involve risks and uncertainties such that actual results may differ materially from these statements. These risks and uncertainties include, among others, any potential adverse events observed in the continuing monitoring of the patients in the clinical trials; the content and timing of decisions by the U.S. Food and Drug Administration, the European Medicines Agency, the European Commission and other regulatory authorities; and those factors detailed in BioMarin’s filings with the Securities and Exchange Commission (SEC), including, without limitation, the factors contained under the caption “Risk Factors” in BioMarin’s Annual Report on Form 10-K for the year ended December 31, 2025, as such factors may be updated by any subsequent filings with the SEC. Investors are urged not to place undue reliance on forward-looking statements, which speak only as of the date hereof. BioMarin is under no obligation, and expressly disclaims any obligation to update or alter any forward-looking statement, whether as a result of new information, future events or otherwise.

BioMarin^®, BioMarin RareConnections^® and VOXZOGO^® are registered trademarks of BioMarin Pharmaceutical Inc.

SOURCE BioMarin Pharmaceutical Inc.