Skytrofa
Skytrofa (lonapegsomatropin or lonapegsomatropin-tcgd) is a prescription growth hormone therapy used to treat children 1 year and older with low growth hormone levels. It's given as a weekly injection under the skin using an autoinjector, which can be done at home. Common side effects include viral infection, fever, cough, nausea, and vomiting.
What is Skytrofa (lonapegsomatropin)?
What is Skytrofa (lonapegsomatropin) used for?
Low growth hormone levels in children 1 year and older and who weigh at least 11.5 kg (25 lbs).
How Skytrofa (lonapegsomatropin) works
Skytrofa (lonapegsomatropin) is a growth hormone analog. It works just like the growth hormone (GH) the body naturally makes. By acting like growth hormone, Skytrofa (lonapegsomatropin) starts a series of steps in the body that help your child grow.
Drug Facts
What are the side effects of Skytrofa (lonapegsomatropin)?
Common Side Effects
- Viral infection (15%)
- Fever (15%)
- Cough (11%)
- Nausea and vomiting (11%)
Other Side Effects
- Bleeding
- Diarrhea
- Stomach pain
- Joint pain
Serious Side Effects
- Serious allergic reactions: hives, dizziness, fever, rash, shaking, itching, nausea, flushing, low blood pressure, trouble breathing, chest pain
- High blood pressure in the brain: changes in vision, headache, nausea, vomiting
- Swelling of the pancreas (pancreatitis): nausea, vomiting, severe abdominal pain that spreads to your back
- Cancer: headaches, seizures, vision problems, changes in behavior, changes in skin color, new moles, changes in the appearance of moles
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- High blood sugar (hyperglycemia)—increased thirst or amount of urine, unusual weakness or fatigue, blurry vision
- Increased pressure around the brain—severe headache, blurry vision, change in vision, nausea, vomiting
- Pancreatitis—severe stomach pain that spreads to your back or gets worse after eating or when touched, fever, nausea, vomiting
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Pros and cons of Skytrofa (lonapegsomatropin)
Pros
Comes with an auto-injector that automatically mixes and injects the dose
Only needs to be given once per week
Can be given at home
Cons
Might be difficult for some people to administer correctly
Needs to be given as an injection under the skin
Common side effects include viral infection, fever, and cough
Pharmacist tips for Skytrofa (lonapegsomatropin)
Mark your calendar with your child's appointments to see their prescriber and get any blood tests done during treatment with Skytrofa (lonapegsomatropin). This helps to make sure their treatment and their hormone levels are properly monitored.
Before starting Skytrofa (lonapegsomatropin), tell your child's care team about all the medications they're taking, especially diabetes medications, corticosteroids, or insulin. These medications interact with Skytrofa (lonapegsomatropin), and your child’s dose might need to be adjusted.
Skytrofa (lonapegsomatropin) should be injected under the skin in the thigh, lower stomach, or buttock. Use a different injection site every time to avoid lipoatrophy, which is the loss or damage of fat tissue at the injection site.
Skytrofa (lonapegsomatropin) cartridges are single-dose. Once mixed, you must throw away the remaining medication after each use, even if there's some left. Don't store the mixed medication for later since it must be used within 4 hours of mixing.
Know your child's dose of Skytrofa (lonapegsomatropin) and the size cartridges you have since there are 9 cartridge strengths available. Depending on your child's dose, you might need to use multiple cartridges and give multiple injections.
If your child misses a dose of Skytrofa (lonapegsomatropin), give it within 2 days of the missed day. If more than 2 days have passed, skip it and continue on the regular schedule. Doses can be taken 2 days before or after the regular day if there are at least 5 days between doses.
Store Skytrofa (lonapegsomatropin) cartridges in the refrigerator in their original carton to protect them from light. You can also store them at room temperature for up to 6 months. If a cartridge is taken out of the refrigerator and then returned, it will still expire 6 months from the first day it was removed.
How to inject Skytrofa (lonapegsomatropin) at home:
Your child's care team will teach you how to give Skytrofa (lonapegsomatropin) injections. Be sure to read the instructions or watch the video on how to mix and inject the medication. Contact your child's prescriber for any questions.
Before giving a dose of Skytrofa (lonapegsomatropin), take the cartridge out of the refrigerator and let it warm to room temperature for about 15 minutes.
Insert the appropriate cartridge, the Skytrofa (lonapegsomatropin) auto-injector will mix the contents during preparation.
To begin the injection, press and hold the green top firmly against the skin. Keep holding for 10 to 15 seconds until you hear 2 loud beeps and see the green top flash twice. The green checkmark icon will light up when the injection is complete.
Throw away the used syringe and needle in a sharps container. Don't throw them away in your trash can. Visit the FDA's website for information on how to safely dispose of sharps in your state.
Frequently asked questions about Skytrofa (lonapegsomatropin)
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What are the risks and warnings for Skytrofa (lonapegsomatropin)?
Skytrofa (lonapegsomatropin) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Higher risk of death in people with a short-term critical illness
Risk factors: Open heart or stomach surgery | Serious injuries | Severe breathing problems
There have been reports of a growth hormone medication similar to Skytrofa (lonapegsomatropin) raising the risk of death when used in people with a critical illness from open heart or stomach surgery, serious injuries, or a severe breathing problem. Let your child's prescriber know right away if they develop any serious health problems while taking this medication.
Severe allergic reactions
Severe allergic reactions to Skytrofa (lonapegsomatropin) are rare but possible. These reactions include life-threatening reactions like anaphylaxis (closing of the throat). If you notice your child experiencing dizziness, a choking sensation, nausea, swelling around the eyes, swelling of the lips or tongue, or difficulty breathing after using Skytrofa (lonapegsomatropin), get medical attention right away.
New or worsening cancer
Risk factors: History of cancer | Genetic causes of short stature
Skytrofa (lonapegsomatropin) shouldn't be used in children with an active tumor or cancer. Let your child's prescriber know if your child has a history of any type of cancer. Growth hormone replacement products like Skytrofa (lonapegsomatropin) have been shown to raise the risk of cancer. Your child's prescriber will monitor your child during and after treatment with Skytrofa (lonapegsomatropin) and will stop treatment at the first sign of potential cancer development. Let them know right away if you notice changes in your child’s behavior, new or worsening headaches, vision problems, changes in skin color, or changes in the size or shape of existing moles.
High blood sugar
Risk factors: Taking higher doses of Skytrofa (lonapegsomatropin) | Obesity | Family history of type 2 diabetes
Skytrofa (lonapegsomatropin) can make the body less sensitive to insulin, the hormone that helps lower blood sugar. This can lead to high blood sugar and raise your child's risk of diabetes. Your child's prescriber might ask you to monitor their blood sugar level while they're taking Skytrofa (lonapegsomatropin). Be aware of symptoms of high blood sugar, such as feeling very thirsty, needing to urinate often, and feeling very tired. Contact your child's prescriber if you notice any of these.
High blood pressure in the brain (intracranial hypertension)
Rarely, a medication similar to Skytrofa (lonapegsomatropin) has caused high blood pressure in the blood vessels in the brain, known as intracranial hypertension. This condition can lead to vision changes and symptoms like headache, nausea, and vomiting. Symptoms typically occur within 2 months of starting treatment. Your child's prescriber will likely perform routine exams before and during treatment with Skytrofa (lonapegsomatropin) to check for this condition.
Swelling in the body
It's possible for Skytrofa (lonapegsomatropin) to cause a build-up of fluid in the body. This can lead to symptoms like swelling (edema), joint pain, muscle pain, and nerve compression problems like carpal tunnel syndrome. Contact your child's prescriber if you notice any swelling in the arms and legs, shortness of breath, or weight gain in a short amount of time.
Low hormone levels
Risk factors: Low pituitary hormone | Untreated low thyroid hormone
Skytrofa (lonapegsomatropin) can lower levels of cortisol, a natural hormone that's involved in many processes, such as controlling blood sugar, blood pressure, and inflammation. Let your prescriber know if you experience symptoms of low cortisol, such as feeling weak, tired, dizzy, losing your appetite, or noticing mood changes.
Skytrofa (lonapegsomatropin) can also lower your thyroid hormone levels, which can prevent the medication from working well. Your prescriber will likely perform routine tests to make sure hormone levels are healthy and adjust the dose if needed.
Bone problems
Since Skytrofa (lonapegsomatropin) stimulates growth in children, it can sometimes cause a hip problem called slipped capital femoral epiphysis, where the thigh bone slips out of the socket. This problem is more common in children who start to grow quickly. Contact your child's prescriber if they have a limp or complains of hip or knee pain during treatment.
If your child has scoliosis, taking Skytrofa (lonapegsomatropin) could make it worse because of their faster growth. But the medication itself doesn't cause this condition. Your child's prescriber will check them regularly for worsening symptoms of scoliosis, such as an uneven waist or shoulders or if their body leans to one side.
Inflammation of the pancreas (pancreatitis)
Risk factors: Children
Rarely, another medication like Skytrofa (lonapegsomatropin) has been linked to pancreatitis, which is inflammation of the pancreas. Children taking Skytrofa (lonapegsomatropin) might have a higher risk than adults. Contact your child's prescriber if they complain of sudden, severe stomach pain.
Sudden death in children with Prader-Willi syndrome
Risk factors: Boys | Children with Prader-Willi syndrome that also have obesity, blocked airways, sleep apnea, or an unknown respiratory infection
Skytrofa (lonapegsomatropin) shouldn't be used in children with growth problems due to a genetic condition called Prader-Willi syndrome. This is because deaths have been reported in children with this condition who were treated with a similar medication and had risk factors like obesity or sleep apnea.
Skytrofa (lonapegsomatropin) dosage forms
Typical dosing for Skytrofa (lonapegsomatropin)
The dose of Skytrofa (lonapegsomatropin) is based on your child's weight.
The typical dose is 0.24 mg/kg injected under the skin once a week.
Skytrofa (lonapegsomatropin) contraindications
A short-term, critical illness from surgery, serious injuries, or a severe breathing problems
Children who have stopped growing (or have a closed growth plates)
Currently have cancer
Active or severe eye damage caused by diabetes (diabetic retinopathy)
Prader-Willi syndrome and have been identified as obese or have severe breathing problems or sleep apnea
What are alternatives to Skytrofa (lonapegsomatropin)?
Low growth hormone levels in children 1 year and older and who weigh at least 11.5 kg (25 lbs).
Low growth hormone levels in children 3 years and older
Certain growth-related conditions in children (e.g., low growth hormone, Turner Syndrome, Prader-Willi Syndrome)
Low growth hormone in adults
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References
Best studies we foundAscendis Pharma Endocrinology Inc. (2021). Instructions for use: Skytrofa® Auto-Injector for SKYTROFA cartridges: Single-patient use.
Ascendis Pharma Endocrinology, Inc. (2024). Skytrofa- lonapegsomatropin-tcgd injection, powder, lyophilized, for solution [package insert]. DailyMed.
Chhiba, P. D., et al. (2021). Lipoatrophy associated with daily growth hormone injections. Endocrinology, Diabetes & Metabolism Case Reports.
Drug Enforcement Administration. (2019). Human growth hormone.
MedlinePlus. (2022). Prader-Willi syndrome.
National Institute of Diabetes and Digestive and Kidney Diseases. (2018). Definition & facts of adrenal insufficiency & Addison’s disease.
Nemours KidsHealth. (2019). Growth plates.
OrthoInfo. (2020). Slipped capital femoral epiphysis.
Thornton, P. S., et al. (2021). Weekly longpegsomatropin in treatment-naïve children with growth hormone deficiency: The phase 3 heiGHt trial. The Journal of Clinical Endocrinology & Metabolism.
U.S. Food and Drug Administration. (2021). Safely using sharps (needles and syringes) at home, at work and on travel.
You and Your Hormones. (2019). Cortisol.
You and Your Hormones. (2021). Growth hormone.
You and Your Hormones. (2021). Insulin.
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