Does “mild” XLH really exist?
Dr. Ginsberg: Hi, I’m Dr. Charles Ginsberg. I'm a nephrologist, and I’ve been managing phosphate-related disorders, including X-linked hypophosphatemia—or XLH—for nearly a decade.
Dr. Smeryage: And I’m Bonnie Smeryage. I’m a nurse practitioner, and I’ve been caring for patients with XLH for 12 years.
Dr. Ginsberg: And this is XLH in Focus. Today, we’re breaking down what “mild XLH” really means—and when and how treatment may be appropriate.
Disclaimer: Dr. Charles Ginsberg is a consultant, and Bonnie Smeryage is a speaker for Kyowa Kirin. Both receive compensation from Kyowa Kirin for their engagements.
TOPIC 1
Dr. Smeryage: Do X-linked hyposphosphatemia symptoms stop in adulthood?
Dr. Ginsberg: I think that’s one of the biggest misconceptions we deal with—that XLH only impacts children and the disease stops once growth is complete.
Dr. Smeryage: In pediatrics, we focus on growth and symptoms like rickets and bowing. But I always tell families that XLH is not just about childhood growth.
Dr. Ginsberg: Exactly. Bones are dynamic—they are constantly renewing themselves to stay healthy, and one of the things they need to do that is phosphate.
Dr. Smeryage: So even after growth plates close, the need for phosphate continues, and the pathophysiology of phosphate wasting doesn’t stop.
TOPIC 2
Dr. Smeryage: What does “mild XLH” mean?
Dr. Ginsberg: I really don’t like the term “mild.” It tells patients to attribute their symptoms to something else because their disease is just “mild.”
Dr. Smeryage: I agree. Clinicians might describe XLH as “mild” based on labs.
Dr. Ginsberg: Right. Maybe a patient’s phosphorus isn’t that low, but duration matters. A week or a month may not mean much, but if phosphorus levels remain low over a long period of time, that’s something we should manage.
Dr. Smeryage: Patients may call their XLH “mild” because that’s how a provider described it to them, or because they’ve become accustomed to their symptoms and see them as mild compared to challenges they had while they were growing up.
Dr. Ginsberg: Exactly. Mild compared to what? Compared to when they were 9? That’s a very different benchmark than looking at the full impact of the disease today.
TOPIC 3
Dr. Ginsberg: How do you assess true disease burden in XLH?
Dr. Smeryage: So in my practice, I’ve seen parents normalize their child’s limitations. They might say, “Well, they’re just not as fast as the other kids on the playground.”
Dr. Ginsberg: Humans adapt. Over time, patients may start to see those limitations as just what’s normal for them.
Dr. Smeryage: I really believe in regular assessments with my patients. I think it’s important to not only look at biochemical markers, but also at how the XLH is impacting their daily lives.
Dr. Ginsberg: I agree. Regular assessments help track the change in disease burden over time and can give us a clearer picture of how patients are progressing.
TOPIC 4
Dr. Ginsberg: Should “mild” cases of XLH be considered for treatment?
Dr. Smeryage: I think too many people think about XLH on a severity scale. The impact of the disease can look different from person to person, but it's a genetic condition—you either have it or you don’t.
Dr. Ginsberg: When I’ve put these types of patients on treatment, there’s kind of a perspective change. What they once called “mild,” they may realize was something they had normalized or just learned to live with.
Dr. Smeryage: And that’s why ongoing assessment is so important. It helps us better understand what "mild” means for each patient, which can help inform treatment decisions.
Dr. Ginsberg: Phosphate wasting doesn’t change from 12 years old to 16 to 20 to 40. And if phosphate wasting remains, that warrants looking into treatment. You only get one skeleton—you can’t get a skeleton transplant.
TOPIC 5
Dr. Ginsberg: Why do you recommend CRYSVITA?
Dr. Smeryage: I recommend CRYSVITA because in my pediatric patients, I’ve seen it help heal rickets or reduce rickets severity, improve leg abnormalities, increase growth, and increase phosphorus levels into the normal range.
Dr. Ginsberg: In adult patients, CRYSVITA can help normalize phosphorus levels, improve osteomalacia, and improve healing of fractures and pseudofractures.
We’ll get into how to talk about CRYSVITA with patients in a moment. But first, let’s take a look at who CRYSVITA is indicated for and when it’s contraindicated.
Indication
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
Important Safety Information
CONTRAINDICATIONS
CRYSVITA is contraindicated:
TOPIC 6
Dr. Ginsberg: How do you start the conversation about CRYSVITA with patients?
Dr. Smeryage: I explain why XLH is not able to correct itself, and how CRYSVITA addresses the problem at the source. So here's a model of our DNA double helix showing a section of the PHEX gene, highlighting a variant. Variants such as these result in excess FGF23. That drives phosphate wasting, and CRYSVITA targets that pathway.
Dr. Ginsberg: And here is our CRYSVITA molecule bound to FGF23. CRYSVITA targets FGF23 to address the root cause of XLH.
It’s about giving them the information—what the disease is doing, what the data show, what to expect from a safety standpoint, and what their options are. And then deciding together what makes sense for them.
CLOSING
Dr. Smeryage: We’re glad we could help put XLH in focus today.
Dr. Ginsberg: Before we wrap up, please continue watching for additional Important Safety Information for CRYSVITA.
WARNINGS AND PRECAUTIONS
Hypersensitivity
Hyperphosphatemia and Risk of Nephrocalcinosis
Hypercalcemia
Injection Site Reactions
ADVERSE REACTIONS
Pediatric Patients
Adult Patients
USE IN SPECIFIC POPULATIONS
PATIENT COUNSELING INFORMATION
You may report side effects to the FDA at (800) FDA-1088
or
www.fda.gov/
medwatch. You may also report side effects to Kyowa Kirin, Inc.
at
1-844-768-3544.
For important risk and use information, please see the full Prescribing Information for CRYSVITA in the link provided.
Revisiting XLH treatment today
Dr. Ginsberg: Hi, I’m Dr. Charles Ginsberg. I'm a nephrologist, and I’ve been managing phosphate-related disorders, including X- linked hypophosphatemia, otherwise known as XLH, for almost a decade.
Mike: And I’m Mike. I’m a dad, a utility company general manager, and a recently retired fire lieutenant. And I'm living with XLH.
Dr. Ginsberg: This is XLH in Focus and today we’re going to talk about how XLH treatment has evolved.
Disclaimer: Dr. Charles Ginsberg is a consultant for and receives compensation from Kyowa Kirin for his engagements. Mike was compensated for his time by Kyowa Kirin.
TOPIC 1
Dr. Ginsberg: I've got Mike in the hot seat to ask him questions about his journey with XLH. What was it like growing up with XLH?
Mike: When I was a kid, they didn’t even call it XLH. I was told I had vitamin D–resistant rickets. I was shorter than everybody. My legs were bowed. My joints hurt after I played too hard. And we never really got clear answers about what was happening with my body. The only treatment available required taking supplements several times a day.
Dr. Ginsberg: For many years, the underlying cause of XLH wasn’t fully understood. We were treating low phosphorus with oral phosphate and active vitamin D taken 3 to 4 times a day, carefully spaced out. It was a challenging daily schedule.
TOPIC 2
Mike: How has our understanding of XLH changed treatment?
Dr. Ginsberg: Once we understood that excess FGF23 was driving phosphate wasting, it changed everything. For years, we were chasing phosphorus levels, but the kidneys were still wasting phosphate.
Mike: It was like trying to fill a gas tank with a hole in the bottom of it.
Dr. Ginsberg: Exactly. Now that we understand the root cause of XLH, we can treat it by targeting FGF23 with CRYSVITA. We’ll come back to what that looks like in real life, but first, let’s take a look at who CRYSVITA is indicated for and when it's contraindicated.
Indication
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
Important Safety Information
CONTRAINDICATIONS
CRYSVITA is contraindicated:
TOPIC 3
Dr. Ginsberg: How did you manage your XLH as you got older?
Mike: I stopped taking supplements at 19 because I didn't want to deal with it anymore. And I felt fine.
Dr. Ginsberg: And that can happen in XLH. Young adults often feel well, and it can seem like XLH is behind them. But XLH is lifelong—you can’t outgrow it.
Mike: By my late 20s, it totally caught up with me. My brain would say “go” but my body would say “no.” I even considered stepping down from my job.
Dr. Ginsberg: Unfortunately, this is a common story. A lot of young adults often stop treatment, and the consequences of stopping treatment may not be immediate, which is why consistent treatment can be so important.
TOPIC 4
Dr. Ginsberg: What made you reconsider returning to treatment?
Mike: This is my daughter at 2 years old. She was diagnosed with XLH around 9 months, and that changed things for me. We started her on oral supplements as soon as possible, mixing phosphorus into applesauce, doing doses throughout the day. And just like when I was a kid, it was very challenging.
Dr. Ginsberg: A child’s diagnosis can shift the way a parent thinks about their own XLH. Many parents were treated with supplements themselves. If that experience was difficult, it can shape how they think about treatment later in life.
Mike: Exactly. I didn’t want her to go through what I went through as a kid. So seeing her start to face the same challenges pushed us to learn more about other treatment options. When we enrolled Lexi in the clinical trial for CRYSVITA, it gave me hope. I had something that I didn’t know was ever going to be possible for me.
Dr. Ginsberg: More on how this led to considering treatment options in a moment.
Important Safety Information
The most common adverse reactions in children with XLH (≥25% in the CRYSVITA group and greater than active control) were pyrexia, injection site reaction, cough, vomiting, pain in extremity, headache, tooth abscess, and dental caries.
TOPIC 5
Dr. Ginsberg: Why did you consider CRYSVITA?
Mike: Of course, everyone’s experience is different. But after my daughter started CRYSVITA, seeing the results along the way really inspired and motivated me.
Dr. Ginsberg: I’m glad to hear your daughter saw that kind of improvement.
Mike: I love this family photo. It’s when they came to visit me at the firehouse.
Dr. Ginsberg: I can really see the change in your daughter.
Mike: I had ignored my XLH for an incredibly long time. I was ready to start taking charge of my own health. Not just for myself, but for my family. I talked with my doctor, and we decided that CRYSVITA could be right for me.
Dr. Ginsberg: It’s great that you talked with your doctor about your options, because CRYSVITA has been effective in treating adults with XLH as well.
TOPIC 6
Dr. Ginsberg: What changed for you after starting CRYSVITA?
Mike: After starting CRYSVITA, I noticed some improvements. I used to experience stiffness after sitting or lying down. After a few months into the treatment, I could tell that my stiffness had improved because getting out of bed was easier in the morning.
After almost a decade of struggling, it was encouraging to feel the change. Sometimes I still feel pain, but I’ve seen improvements in my phosphorus levels. When I first started CRYSVITA, I experienced restless leg syndrome, which is a common side effect in adults. I realize everyone’s experience is different, and this is just my own.
Dr. Ginsberg: I’m glad you’ve seen improvement since taking CRYSVITA. In a clinical trial in adults, CRYSVITA helped increase and maintain phosphorus levels over 24 weeks, with some patients seeing phosphorus levels increase as early as 1 week after starting CRYSVITA.
Everyone’s experience with CRYSVITA is different, and results vary from person to person.
TOPIC 7
Mike: What would you tell others about CRYSVITA?
Dr. Ginsberg: Until CRYSVITA was approved, treatment often meant trying to replace phosphorus that the body was still losing—like you said earlier, Mike, trying to fill a gas tank with a hole in it. With CRYSVITA, we can address the cause of chronic hypophosphatemia in XLH. For adult patients, I encourage colleagues to reassess disease burden and consider if a change in their current treatment approach is appropriate.
What would you tell others with XLH?
Mike: I’d want anyone with XLH to know it’s never too late to ask their doctor if starting—or restarting—treatment with CRYSVITA is right for them. I’m glad I decided to talk to my doctor to start treating my XLH with CRYSVITA. I can balance spending time with my kids and continue doing the jobs that I love.
CLOSING
Dr. Ginsberg: Thank you for sharing your story with us, Mike.
Before we close, please continue watching for additional Important Safety Information for CRYSVITA.
Thanks for watching.
WARNINGS AND PRECAUTIONS
Hypersensitivity
Hyperphosphatemia and Risk of Nephrocalcinosis
Hypercalcemia
Injection Site Reactions
ADVERSE REACTIONS
Pediatric Patients
Adult Patients
USE IN SPECIFIC POPULATIONS
PATIENT COUNSELING INFORMATION
You may report side effects to the FDA at (800) FDA-1088
or
www.fda.gov/
medwatch. You may also report side effects to Kyowa Kirin, Inc.
at
1-844-768-3544.
For important risk and use information, please see the full Prescribing Information for CRYSVITA in the link provided.
Revisiting XLH treatment today
Dr Rush: Hello, and welcome to this clinical presentation on X-linked hypophosphatemia and the recent pediatric and adult guidelines regarding treatment decisions. My name is Dr Eric Rush, and I’ll be guiding today’s video. Before we begin, I’d like to introduce myself. I’m a clinical geneticist at Children’s Mercy Hospital in Kansas City, Missouri, and a professor of pediatrics at the University of Missouri-Kansas City School of Medicine. I'm also a speaker for Kyowa Kirin and receive compensation from Kyowa Kirin for my engagements.
Narrator: The visuals and avatar in this video were created using an AI tool. This avatar represents a digital twin of Dr Rush’s and was created with his consent. Dr Rush has reviewed and approved all the clinical information and insights spoken to in this video.
Dr Rush: Let's get into what exactly XLH is. Commonly misperceived as a childhood condition, XLH is a progressive phosphate-wasting disease. Like most genetic diseases, there is a hereditary component. About 70-80% of patients have an affected parent, but that also means that 20-30% of cases are spontaneous. XLH can be challenging to diagnose—many physicians have never heard of it, and the presenting symptoms can differ amongst patients. Misdiagnoses or even delayed diagnoses can lead to delays in treatment. Initially, patients may be referred to specialists when there is poor growth or rickets in childhood. However, many symptoms can persist and progress into adulthood. Knowing the ways XLH can present is essential because the eyes won’t see what the mind doesn’t know.
Dr Rush: The mechanisms of XLH are driven by variants in the PHEX gene, which lead to increased levels of FGF23, a peptide hormone, that functions as a renal phosphaturic. Phosphorus is then wasted by the kidneys into the urine, which results in low levels of phosphate in the blood. This, in turn, leads to weaker bones.
Dr Rush: Testing phosphorus level in the blood is among the key first steps in diagnosing XLH as one of the main biochemical features of XLH is a low fasting serum phosphorus level. Accurate diagnosis depends on assessing phosphate based on age-appropriate levels. As physicians, we must be intentional about ordering it because phosphorus isn’t included on the complete metabolic panel. I tell colleagues that when you’re evaluating a patient for any metabolic bone disease or musculoskeletal symptoms, phosphorus must be included. Results from other biochemical tests, as shown here, can also point to XLH. If phosphorus is below normal for a patient’s age and gender, it’s essential to follow up with genetic testing to differentiate XLH from similar conditions.
Dr Rush: Recently, I was a coauthor on the international guidelines for adult and pediatric patients with XLH. The guidelines are based on GRADEd criteria (Grading of Recommendations, Assessment, Development, and Evaluation), which is a way to systematically examine evidence. So, these guidelines consider clinical evidence, any additional literature, and expert interpretation. The language is conservative by design—the strongest evidence is given a recommendation, and weaker or conditional evidence is given a suggestion.
Dr Rush: The adult guidelines present an important paradigm shift because this population is treated less frequently for XLH. The GRADEd treatment recommendations were based on 2 systematic reviews. The first compared the impact of CRYSVITA versus conventional therapy, consisting of active vitamin D and phosphate salts, or the impact of CRYSVITA versus no therapy on patient-important outcomes. The second review compared the impact of conventional therapy versus no therapy on patient-important outcomes. As you can see on screen, the guidelines have a GRADEd recommendation for the use of CRYSVITA in adults with fractures or pseudofractures. This is because, based on the evidence, the panel was confident that the desirable effects of CRYSVITA outweigh the risks in this population. Although we don’t have as strong evidence for adults without fractures or pseudofractures, the data we have suggest that CRYSVITA may be beneficial, although uncertainty remains, which is why it earns a weaker GRADEd suggestion. I encourage providers to review the adult guidelines in full to gain a clearer understanding of how their patients may benefit with CRYSVITA.
Dr Rush: The GRADEd treatment recommendations of the pediatric guidelines were developed in a similar way as the adult guidelines. An additional limitation in the development of these guidelines was the absence of a Delphi process, which some authorities recommend to enhance the trustworthiness of a guideline. Furthermore, geographic representation was not equal from all regions. For children 12 months and over, CRYSVITA is recommended over conventional therapy. This recommendation shifts to a suggestion for children ages 6-12 months—they are consistent with the indication for CRYSVITA, but we have less evidence in that population. With bone diseases like XLH, patients should receive medical therapy at least until peak bone mass, if not beyond, and this is reflected in the guidelines. The overarching guidelines support starting medical therapy in children 6 months of age and older and in adults as soon as possible after diagnosis, and continue through several years following epiphyseal closure. A proactive treatment approach, initiated as early as possible in appropriate patients, is essential in XLH as recommended by the updated treatment guidelines.
Dr Rush: I’d like to now spend some time reviewing exactly what CRYSVITA is and some Important Safety Information. CRYSVITA (burosumab-twza) is an FGF23 blocking antibody indicated for the treatment of X-linked hypophosphatemia in adult and pediatric patients 6 months of age and older. Importantly, CRYSVITA is contraindicated in patients with concomitant use with oral phosphate and or active vitamin D analogs due to the risk of hyperphosphatemia. Along with patients who have a serum phosphorus level within or above the normal range for age, and patients with severe renal impairment or end stage renal disease because these conditions are associated with abnormal mineral metabolism. Please continue watching for the full Important Safety Information, and see the full Prescribing Information for CRYSVITA linked on this site.
Dr Rush: Now let's take a look at how CRYSVITA works. Using a leaky bucket metaphor to describe renal phosphate wasting, CRYSVITA works by patching up some holes in the bucket to reduce the leaking, instead of continuing to pour more water into it. CRYSVITA is the first and only treatment to target the cause of increased FGF23 in XLH.
Dr Rush: Ideally, pediatric patients who are at least 6 months old should start CRYSVITA at time of diagnosis if appropriate, and continue at least through completion of growth or peak bone mass. CRYSVITA is also approved for use in adults, demonstrating that XLH isn't only a childhood disease. With increased awareness of XLH, the clinical guidelines set forth, and the availability of therapies like CRYSVITA, we can hopefully provide additional treatment options for appropriate children 6 months of age and older and adults with this rare condition.
Dr Rush: Please continue watching to hear the full Important Safety Information for CRYSVITA. Additionally, you can access the full Prescribing Information for CRYSVITA linked on this site for important risk and use information. I’d like to thank those of you who joined me today. Please continue watching for the full Important Safety Information.
Indication
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
Important Safety Information
CONTRAINDICATIONS
CRYSVITA is contraindicated:
WARNINGS AND PRECAUTIONS
Hypersensitivity
Hyperphosphatemia and Risk of Nephrocalcinosis
Hypercalcemia
Injection Site Reactions
ADVERSE REACTIONS
Pediatric Patients
Adult Patients
USE IN SPECIFIC POPULATIONS
PATIENT COUNSELING INFORMATION
You may report side effects to the FDA at (800) FDA-1088
or
www.fda.gov/
medwatch. You may also report side effects to Kyowa Kirin, Inc.
at
1-844-768-3544.
For important risk and use information, please see the full Prescribing Information for CRYSVITA.
This website is intended for use by US residents only.
XLH in focus
Watch expert conversations on the diagnosis, assessment, and management of XLH.
Does “mild” XLH really exist?
Hear from Charles Ginsberg, MD, MAS, and Bonnie Smeryage, DNP, for their medical insights on the term "mild" XLH and how evaluating disease burden can identify patients who may benefit from treatment with CRYSVITA.
Revisiting XLH treatment today
Hear Charles Ginsberg, MD, MAS, and Mike, a real patient, discuss how our understanding of XLH has evolved, why treatment conversations are changing, and how CRYSVITA fits in for the treatment of XLH.
Explore clinical perspectives
Learn about guidelines and management strategies for XLH from Eric T. Rush, MD, FAAP.
CRYSVITA resources for HCPs treating XLH
Explore these CRYSVITA resources designed to help HCPs navigate treatment for pediatric and adult patients with X-linked hypophosphatemia (XLH).
Kyowa Kirin Cares CRYSVITA enrollment form
A form to enroll patients who have been prescribed CRYSVITA into the Kyowa Kirin Cares program.
CRYSVITA start guide for HCPs
A guide that walks through the steps of getting patients started on CRYSVITA—from patient enrollment and coverage authorization to product acquisition and delivery.
How to use CRYSVITA guide
A guide with essential tips for HCPs on preparation, administration, product storage, and handling of CRYSVITA.
Clinical Practice Guidelines for children with XLH
An overview of International Working Group treatment recommendations for managing XLH in children.
Clinical Practice Guidelines for adults with XLH
An overview of International Working Group treatment recommendations for managing XLH in adults.
Join the Specialist Finder
Are you an XLH specialist that would like to be added to the Finder? Opt in today.
ADULT CASE STUDY
A patient case study adapted from a real-life example that provides medical history, diagnosis, and treatment information for an adult patient with inherited XLH.
PEDIATRIC CASE STUDY
A patient case study adapted from a real-life example that provides medical history, diagnosis, and treatment information for a pediatric patient with spontaneous XLH.
CRYSVITA resources for patients with XLH and caregivers
Explore helpful CRYSVITA resources with your patients, ranging from patient events to family support guides.
Brochure for adults with XLH
A brochure for adults with XLH who want to learn more about how CRYSVITA can help treat their condition.
Brochure for caregivers of children with XLH
A brochure for caregivers of children with XLH who want to learn more about how CRYSVITA treatment may be able to help their child.
Specialist Finder
A tool to help patients and caregivers find an HCP near them with experience managing XLH.
Educational events for patients with XLH and caregivers
Encourage your patients to attend an event to learn more about CRYSVITA from XLH specialists and to connect with others in the XLH community.
SEE ALL EVENTS
Connecting with others in the XLH community
The groups listed below provide support and education for people living with XLH.
Information listed for educational purposes only. This is a curated list and is not meant to be an exhaustive list of all organizations, services, or online resources. These resources are created by and hosted on third-party websites that are not reviewed, controlled, or endorsed by Kyowa Kirin, Inc.
The XLH Network
The XLH Network, a 501(c)(3) nonprofit organization, seeks to connect people around the world who are affected by or interested in learning more about XLH. The XLH Network connects affected individuals, families, and medical professionals.
National Organization for Rare Disorders (NORD)
NORD is a patient advocacy organization dedicated to individuals with rare diseases and the organizations that serve them.
Global Genes
Global Genes is a rare disease patient advocacy organization that works to build awareness, educate the global community, and provide connections and resources.
Got Transition
Got Transition is the national resource center for healthcare transition. Its aim is to improve the transition from pediatric to adult health care through the use of evidence-driven strategies for HCPs, youth, young adults, and their caregivers.
Stay connected
Set up time with a representative to talk more about CRYSVITA or sign up for more information on CRYSVITA for the treatment of XLH.
Actor portrayal
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
CONTRAINDICATIONS
CRYSVITA is contraindicated:
WARNINGS AND PRECAUTIONS
Hypersensitivity
Hyperphosphatemia and Risk of Nephrocalcinosis
Hypercalcemia
Injection Site Reactions
ADVERSE REACTIONS
Pediatric Patients
Adult Patients
USE IN SPECIFIC POPULATIONS
PATIENT COUNSELING INFORMATION
You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.
For important risk and use information, please see the full Prescribing Information for CRYSVITA.
CRYSVITA® (burosumab-twza) is a fibroblast growth factor 23 (FGF23) blocking antibody indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.
CONTRAINDICATIONS
CRYSVITA is contraindicated:
WARNINGS AND PRECAUTIONS
Hypersensitivity
Hyperphosphatemia and Risk of Nephrocalcinosis
Hypercalcemia
Injection Site Reactions
ADVERSE REACTIONS
Pediatric Patients
Adult Patients
USE IN SPECIFIC POPULATIONS
PATIENT COUNSELING INFORMATION
You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.
For important risk and use information, please see the full Prescribing Information for CRYSVITA.
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COMM-US-CRY-0779 June 2026
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