Burosumab

Burosumab is a prescription medication used to treat the symptoms of X-Linked Hypophosphatemia and Tumor-Induced Osteomalacia. 

• Burosumab is available under the following different brand names: Crysvita, burosumab-twza

Common side effects of Burosumab include:

• headache,
• dizziness,
• pain in the arms, legs, or back,
• vomiting,
• constipation,
• restless feeling in the legs,
• fever,
• tooth infection,
• decreased vitamin d levels,
• increased phosphorous levels, and
• pain, redness, itching, swelling, bruising, or a hard lump where the medicine was injected

Serious side effects of Burosumab include:

• hives,
• difficulty breathing, and
• swelling of the face, lips, tongue, or throat

Rare side effects of Burosumab include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Injectable solution, single-dose vials

• 10 mg/mL
• 20 mg/mL
• 30 mg/mL

X-Linked Hypophosphatemia

Adult dosage

• 1 mg/kg Subcutaneous every 4 weeks; round dose to nearest 10 mg
• Not to exceed 90 mg/dose

Pediatric dosage

• Below 6 months: Safety and efficacy not established
• Above 6 months
  • Children below 10 kg
    • 1 mg/kg Subcutaneous every 2 weeks; round dose to nearest 1 mg
  • Children above 10 kg
    • 0.8 mg/kg Subcutaneous every 2 weeks; round dose to nearest 10 mg
    • Minimum weight-based starting dose is 10 mg up to a maximum dose of 90 mg

Tumor-induced Osteomalacia

Adult dosage

• 0.5 mg Subcutaneous every 4 weeks initially; may increase the dose up to 2 mg/kg every 2 weeks, not to exceed 180 mg/dose

Pediatric dosage

• Children aged 2 to below 18 years
  • Initial: 0.4 mg Subcutaneous every 2 weeks; round dose to nearest 10 mg
  • May increase up to 2 mg/kg every 2 weeks; not to exceed 180 mg/dose
  • Do not adjust the dose more frequently than every 4 weeks

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Burosumab has no noted severe interactions with any other drugs.
• Burosumab has no noted serious interactions with any other drugs.
• Burosumab has no noted moderate interactions with any other drugs.
• Burosumab has no noted minor interactions with any other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• Coadministration with oral phosphate and active vitamin D analogs
• Serum phosphorus within or above the reference range for age
• Severe renal impairment or end-stage renal disease (these conditions are associated with abnormal mineral metabolism

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Burosumab?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Burosumab?”

Cautions

• Hypersensitivity reactions (.g, rash, urticaria) reported; discontinue if serious hypersensitivity reactions occur and initiate appropriate medical treatment
• Increases in serum phosphorus to above ULN may be associated with an increased risk of nephrocalcinosis; patients already taking burosumab and with tumor-induced osteomalacia who undergo treatment of underlying tumor should have dose interrupted or reduced based on serum phosphorus levels to prevent hyperphosphatemia
• Local injection site reactions may occur; discontinue if severe injection site reactions occur and administer appropriate medical treatment

Pregnancy and Lactation

• There are no available data on use in pregnant women to inform a drug-associated risk of adverse developmental outcomes
• In utero, burosumab exposure in cynomolgus monkeys did not result in teratogenic effects; adverse effects (.g, late fetal loss, preterm birth) were observed in pregnant cynomolgus monkeys; however, these effects are unlikely to indicate clinical risk because they occurred at a drug exposure that was 64-fold higher, by AUC, than the human exposure at 1 mg/kg every 4 weeks and was accompanied in the non-XLH monkeys by maternal hyperphosphatemia and placental mineralization
• Report pregnancies to the Ultragenyx Adverse Event reporting line at 1-888-756-8657
• Lactation
  • There is no information regarding the presence of burosumab in human milk or the effects on milk production or the breastfed infant
  • Maternal IgG is present in breast milk; however, the effects of local GI exposure and limited systemic exposure to burosumab in the breastfed infant are unknown
  • Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for burosumab and any potential adverse effects on the breastfed infant from burosumab or the underlying maternal condition