Publicado 17/05/2018 14:35:07CET
Treatment with Crysvita showed a significant improvement in mean alkaline phosphatase levels into the normal range after 40 weeks of treatment, compared to conventional therapy. Patients treated with Crysvita also demonstrated a greater numeric but not statistically significant improvement in growth (height z-score and growth velocity) and in the six-minute walk test, compared to conventional therapy.
Safety and Tolerability
The Crysvita safety profile observed in this study was generally consistent with that seen in other Crysvita pediatric XLH studies. There were no treatment discontinuations and no deaths reported in the study. There were three serious adverse events in the Crysvita arm and one serious adverse event in the conventional therapy arm, none of which were considered treatment-related. In the Crysvita arm, 45% of patients had injection site reactions, all but one were mild and none were considered serious. No clinically meaningful changes were observed in mean serum calcium and serum intact parathyroid hormone in either treatment arm. No clinically significant changes were observed in renal ultrasounds pre-and post-treatment in either treatment arm.
Full results will be presented at an upcoming medical meeting.
About X-linked hypophosphatemia (XLH)
XLH is a rare, hereditary, progressive and lifelong skeletal disorder characterized by renal phosphate wasting caused by excess FGF23 production. It affects both children and adults. In children, XLH causes rickets that leads to lower-extremity deformity, delayed growth and decreased height. Adults with XLH have an increased risk of fractures.
Crysvita is a recombinant fully human monoclonal IgG1 antibody, discovered by Kyowa Hakko Kirin, against the phosphaturic hormone fibroblast growth factor 23 (FGF23). FGF23 is a hormone that reduces serum levels of phosphorus and active vitamin D by regulating phosphate excretion and active vitamin D production by the kidney. Phosphate wasting in XLH is caused by excessive levels and activity of FGF23. Crysvita is designed to bind to and thereby inhibit the biological activity of FGF23. By blocking excess FGF23 in patients, Crysvita is intended to increase phosphate reabsorption from the kidney and increase the production of active vitamin D, which enhances intestinal absorption of phosphate and calcium.
On April 17, 2018 the U.S. Food and Drug Administration (FDA) approved Crysvita for the treatment of XLH in adult and pediatric patients 1 year of age and older. On February 23, 2018 Crysvita received a positive European Commission decision granting conditional marketing authorization Crysvita for the treatment of XLH with radiographic evidence of bone disease in children 1 year of age and older and adolescents with growing skeletons. This Phase 3 pediatric study will serve as a confirmatory study in Europe; it was not required for the regulatory application in the U.S.
Kyowa Hakko Kirin, Kyowa Kirin International, a wholly owned subsidiary of Kyowa Hakko Kirin, and Ultragenyx have been collaborating in the development and commercialization of Crysvita globally, based on the collaboration and license agreement between Kyowa Hakko Kirin and Ultragenyx.
INDICATION (IN THE U.S.)
Crysvita is indicated for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients one year of age and older.
IMPORTANT SAFETY INFORMATION
Crysvita should not be taken if:
- An oral phosphate supplement and a specific form of vitamin D supplement are taken - Phosphorus levels from a blood sample are within or above the normal range for age - Kidney problems are present
What is the most important information to know about Crysvita?
- Some patients developed allergic reactions (rash and hives) while taking Crysvita. Doctors will monitor for symptoms of an allergic reaction while Crysvita is taken. - 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. Doctors will collect samples to monitor 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 (hematoma).
What are the possible side effects of Crysvita?
- The most common adverse reactions that were seen in children with XLH are: - Headache - Injection site reaction - Vomiting - Fever - Pain in arms and legs - Decreased vitamin D levels - Rash - Toothache - Muscle pain - Tooth infection - Dizziness - The most common adverse reactions that were seen in adults with XLH are: - Back pain - Headache - Tooth infection - Restless leg syndrome - Decreased vitamin D levels - Dizziness - Constipation - 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.
Before taking Crysvita, doctors should be informed about all medical conditions, including if:
- One is pregnant, thinks she may be pregnant, or plans to become pregnant. There is not enough experience to know if Crysvita may harm an unborn baby. Report pregnancies to the Ultragenyx Adverse Event reporting line at 1-888-756-8657. - One is breastfeeding or plans to breastfeed. There is not enough experience to know if Crysvita passes into breast milk. Women should talk with their doctors about the best way to feed their babies while taking Crysvita.
While taking Crysvita, doctors should be informed if one experiences:
- An allergic reaction such as rash or hives - A rash, swelling, bruising or other reaction at the injection site - New or worsening restless leg syndrome
These are not all the possible side effects of Crysvita. Doctors should be contacted for medical advice about side effects.
Side effects may be reported to the FDA at (800) FDA-1088 or http://www.fda.gov/medwatch. Side effects may also be reported to Ultragenyx at 1-888-756-8657.
Please see full Prescribing Information [http://www.ultragenyx.com/file.cfm/29/docs/Crysvita_Full_Prescribing_Information.pdf ] for additional Important Safety Information.
Ultragenyx is a biopharmaceutical company committed to bringing to patients novel therapies for the treatment of rare and ultra-rare diseases, with a focus on serious, debilitating genetic diseases. Founded in 2010, the company has rapidly built a diverse portfolio of approved and investigational therapies to address diseases for which the unmet medical need is high, the biology for treatment is clear, and for which there are no approved therapies.
The company is led by a management team experienced in the development and commercialization of rare disease therapeutics. Ultragenyx's strategy is predicated upon time and cost-efficient drug development, with the goal of delivering safe and effective therapies to patients with the utmost urgency.
For more information on Ultragenyx, please visit the company's website at http://www.ultragenyx.com.
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