Kyowa Kirin North America Assumes Commercial Leadership Role for CRYSVITA® (burosumab-twza) Injection in North America

  • Kyowa Kirin now leads commercial efforts for CRYSVITA in 40 countries/regions around the world

  • Company commits to keep patient needs at the forefront of commercial and education efforts

BEDMINSTER, N.J., April 27, 2023 /PRNewswire/ -- Kyowa Kirin, Inc., an affiliate of Kyowa Kirin Co., Ltd. (Kyowa Kirin, TSE: 4151), a top 50 global specialty pharmaceutical company, today assumes primary commercial leadership for CRYSVITA® (burosumab-twza) injection in the United States and Canada from Ultragenyx Pharmaceutical, Inc., a transition planned for from the start of their decade-long collaboration. Initially discovered and developed by Kyowa Kirin, CRYSVITA is a first-in-class medicine used to treat adults and children 6 months of age and older with X-linked hypophosphatemia (XLH) and adults and children 2 years of age and older with fibroblast growth factor 23 (FGF23)–related hypophosphatemia in tumor-induced osteomalacia (TIO) when the tumor cannot be located or removed. The transition builds on the company's existing commercial portfolio and commitment to address the needs of people living with rare diseases.

“Our collaboration with Ultragenyx has been a great success for children and adults living with XLH and TIO. Their contributions were instrumental in expediting late-stage trials, securing regulatory approval, and delivering treatment to thousands of patients,” said Steve Schaefer, President, Kyowa Kirin North America. “Kyowa Kirin intends to build on the successful launch and broad access that’s been established for CRYSVITA, as well as the learnings we have from working alongside XLH and TIO communities around the world, to bring more research, education, and support to patients in North America.”

To prepare for its new commercial leadership role in North America, Kyowa Kirin has engaged with community leaders and people living with XLH and TIO to gain perspective on their experiences and how best to support them. The company has distilled these conversations into a pledge that articulates how it will act to ensure patient voices are heard and reflected in the company's decision-making going forward. To read the Pledge go here.

About the Partnership

Kyowa Kirin entered into a collaboration agreement with Ultragenyx in 2013 to hasten late-stage clinical studies and delivery of CRYSVITA to patients. Ultragenyx led Phase 3 studies and took responsibility for launching the medicine in the U.S., Canada, Latin America, and Turkey, while Kyowa Kirin leveraged its global footprint and capabilities to launch CRYSVITA across Europe, Asia, Australia, and the Middle East in addition to global manufacturing and distribution.

As part of the agreement, primary commercial responsibility for CRYSVITA in the U.S. and Canada would revert to Kyowa Kirin five years after first commercial use. During this time, the company experienced significant growth in North America, making significant investments in talent, technology, and infrastructure to support its rare disease business and services for patients, including the creation of Kyowa Kirin Cares, its comprehensive patient support program first launched to support the company's oncology franchise. Starting May 1, 2023, all support services for CRYSVITA patients and caregivers in the U.S. will be provided through this program.

In addition to leading commercial efforts in Latin America and Turkey, Ultragenyx will continue to work with Kyowa Kirin for the next 12 months, providing support for some commercial activities in North America.

About XLH and TIO

X-linked hypophosphatemia is a rare, lifelong, genetic disease that can impact the bones and muscles in both children and adults. Tumor-induced osteomalacia is an extremely rare, difficult-to-diagnose disease caused by slow-growing tumors that occur throughout the body.

In XLH and TIO, the body doesn't hold on to enough phosphorus, which is an essential mineral for bone health. This is due to the production of excess fibroblast growth factor 23 (FGF23), causing the body to release too much phosphorus through the urine. When phosphorus levels are too low (hypophosphatemia), it can cause the softening and weakening of growing bones in children (rickets) and mature bones in adults (osteomalacia).

In children, XLH typically appears as bowed legs or knock knees. Over time, bone weakening can also lead to bone abnormalities in the legs, delayed growth, and short stature. In adults, XLH may cause osteomalacia, fractures and pseudo-fractures, and hypophosphatemia. Patients with TIO may develop multiple bone abnormalities and can experience symptoms including severe hypophosphatemia, osteomalacia, and fractures. Symptoms are progressive and can lead to long-term disabilities, so it is vital that TIO be treated as soon as possible.


CRYSVITA is a recombinant fully human monoclonal IgG1 antibody, discovered by Kyowa Kirin, which binds to and inhibits the biological activity of FGF23, the underlying cause of hypophosphatemia in XLH and TIO. By blocking FGF23, CRYSVITA helps to restore phosphorus reabsorption in the kidneys and increase the production of active vitamin D, which enhances intestinal absorption of phosphate and calcium.

U.S. CRYSVITA Indication

CRYSVITA is a prescription medicine used to treat adults and children 6 months of age and older with X-linked hypophosphatemia and adults and children 2 years of age and older with fibroblast growth factor 23 (FGF23)–related hypophosphatemia in tumor-induced osteomalacia when the tumor cannot be located or removed.

Important Safety Information

You should not take CRYSVITA if:

  • You take an oral phosphate supplement and/or a specific form of vitamin D supplement (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).
  • Your phosphorus levels from a blood sample are within or above the normal range for age. You have kidney problems.

What is the most important information you should know about CRYSVITA?

  • Some patients developed allergic reactions (e.g., rash and hives) while taking CRYSVITA. Your doctor will monitor you for symptoms of an allergic reaction while you are taking CRYSVITA.
  • High levels of phosphorus in the blood have been reported in some patients taking CRYSVITA. This may be related to a risk of high calcium levels in the kidneys. Your doctor will collect blood samples to monitor your levels.
  • Administration of CRYSVITA may result in reactions at the injection site, such as hives, reddening of the skin, rash, swelling, bruising, pain, severe itching of the skin, and collection of blood outside of a blood vessel (i.e., hematoma).
  • If you are taking CRYSVITA for TIO, your doctor will have you stop your CRYSVITA treatment temporarily if you are undergoing treatment for your tumor (e.g., surgical removal of the tumor or radiation therapy).

What are the possible side effects of CRYSVITA?

  • Adverse reactions that were seen in children with XLH are:
    • Fever
    • Injection site reaction
    • Cough
    • Vomiting
    • Pain in arms and legs
    • Headache
    • Tooth abscess
    • Dental cavities
    • Diarrhea
    • Decreased vitamin D levels
    • Toothache
    • Constipation
    • Muscle pain
    • Rash
    • Dizziness
    • Nausea
  • Adverse reactions that were seen in adults with XLH are:
    • Back pain
    • Headache
    • Tooth infection
    • Restless legs syndrome
    • Decreased vitamin D levels
    • Dizziness
    • Constipation
    • Muscle spasms
    • Phosphorus levels increased in the blood
  • Narrowing of the spaces within the spine is common in adults with XLH, and pressure on the spinal cord has been reported in adults taking CRYSVITA. It is not known if taking CRYSVITA worsens the narrowing of the spaces within the spine or the pressure on the spinal cord.
  • Adverse reactions that were seen in adults with TIO are:
    • Tooth abscess
    • Muscle spasms
    • Dizziness
    • Constipation
    • Injection site reaction
    • Rash
    • Headache

Before taking CRYSVITA, tell your doctor about all of your medications (including supplements) and medical conditions, including if you:

  • Are taking oral phosphate and/or active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).
  • Are pregnant, think you may be pregnant, or plan to become pregnant. There is not enough experience to know if CRYSVITA may harm your unborn baby. Report pregnancies to the Kyowa Kirin, Inc. Adverse Event reporting line at 1-844-768-3544.
  • Are breastfeeding or plan to breastfeed. There is not enough experience to know if CRYSVITA passes into your breast milk. Talk with your doctor about the best way to feed your baby while you receive CRYSVITA.

While taking CRYSVITA, tell your doctor if you experience:

  • An allergic reaction such as rash or hives
  • A rash, swelling, bruising, or other reaction at the injection site
  • New or worsening restless legs syndrome

These are not all the possible side effects of CRYSVITA. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at (800) FDA-1088 or 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.

About Kyowa Kirin

Kyowa Kirin strives to create and deliver novel medicines with life-changing value. As a Japan-based Global Specialty Pharmaceutical Company with a more than 70-year heritage, we apply cutting-edge science including expertise in antibody research and engineering, to address the needs of patients and society across multiple therapeutic areas including Nephrology, Oncology, Immunology/Allergy and Neurology. Across our four regions – Japan, Asia Pacific, North America and EMEA/International – we focus on our purpose, to make people smile, and are united by our shared values of commitment to life, teamwork/Wa, innovation, and integrity. You can learn more about the Kyowa Kirin North America at:

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