Lonapegsomatropin

Lonapegsomatropin is a prescription medication indicated for the treatment of pediatric patients aged 1 year and above who weigh 11.5 kg and above and have growth failure caused due to inadequate secretion of endogenous growth hormone (GH).

• Lonapegsomatropin is available under the following different brand names: Skytrofa, lonapegsomatropin-tcgd

Common side effects of lonapegsomatropin include:

• viral infection
• fever
• cough
• nausea and vomiting
• bleeding
• diarrhea
• abdominal pain
• joint pain, stiffness, and swelling

Serious side effects of lonapegsomatropin include:

• hives
• difficulty breathing
• swelling of the face, lips, tongue, or throat
• unusual bleeding
• easy bruising
• diarrhea
• abdominal pain
• joint pain and swelling

Rare side effects of lonapegsomatropin 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 as a result 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.

Pediatric dosage

Injection, lyophilized powder for reconstitution

• 3 mg
• 3.6 mg
• 4.3 mg
• 5.2 mg
• 6.3 mg
• 7.6 mg

Growth Hormone Deficiency

• Children younger than a year: Safety and efficacy not established
• Children aged 1 year and above and weighing 11.5 kg and more
• Naïve patients and patients switching from daily somatropin therapy: 0.24 mg/kg IV every week
• Individualize and titrate dosage based on response
• Discontinue once epiphyseal fusion has occurred

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.

• Lonapegsomatropin has severe interactions with no other drugs
• Lonapegsomatropin has no noted serious interactions with any other drugs
• Lonapegsomatropin has moderate interactions with at least 67 drugs
• Lonapegsomatropin 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 the products you use. 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

• Acute critical illness after open heart surgery, abdominal surgery, multiple accidental traumas, or those with acute respiratory failure
• Hypersensitivity to somatropin or any of the excipients
• Closed epiphyses
• Active malignancy, owing to risk of malignancy progression
• Active proliferative or severe nonproliferative diabetic retinopathy
• Prader-Willi syndrome who are severely obese, have a history of upper airway obstruction or sleep apnea, or have severe respiratory impairment

Effects of drug abuse

• None

Short-Term Effects

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

Long-Term Effects

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

Cautions

• Increased mortality reported among patients with acute critical illness, owing to complications following open heart surgery, abdominal surgery, multiple accidental traumas, or those with acute respiratory failure; safety of continuing treatment in such patients receiving replacement doses has not been established
• Serious systemic hypersensitivity reactions (e.g., anaphylactic reactions, angioedema) reported; inform patients and caregivers that such reactions are possible and to seek immediate medical attention if allergic reaction occurs
• May decrease insulin sensitivity, particularly at higher doses; previously undiagnosed impaired glucose tolerance and overt type 2 diabetes mellitus (DM) may be unmasked; closely monitor glucose levels when initiating and during treatment in patients with preexisting type 1 or type 2 DM or impaired glucose tolerance; adjust doses of antihyperglycemic drugs as needed
• Fluid retention may occur; clinical manifestations of fluid retention (e.g., edema, arthralgia, myalgia, nerve compression syndromes including carpal tunnel syndrome/paresthesia) are usually transient and dose-dependent
• Undiagnosed or untreated hypothyroidism may prevent optimal treatment response; perform periodic thyroid function tests and initiate or appropriately adjust thyroid hormone replacement therapy when indicated
• Reports of fatalities after initiating therapy with somatropin documented in pediatric patients with Prader-Willi syndrome who had 1 and more of the following risk factors: severe obesity, history of upper airway obstruction or sleep apnea, or unidentified respiratory infection; male patients with 1 or more factors may be at greater risk than female patients
• Not indicated for the treatment of pediatric patients who have growth failure due to genetically confirmed Prader-Willi syndrome
• Slipped capital femoral epiphysis may occur more frequently in patients undergoing rapid growth; evaluate patients with the onset of a limp or complaints of hip or knee pain
• Pancreatitis reported; consider pancreatitis in patients who develop persistent severe abdominal pain
• When somatropin is administered SC at the same site over a long period, tissue atrophy may result; avoid by rotating the injection site
• Treated patients who have or are at risk for pituitary hormone deficiency(s) may be at risk for reduced serum cortisol levels and/or unmasking of central (secondary) hypoadrenalism; patients treated with glucocorticoid replacement for previously diagnosed hypoadrenalism may require an increase in their maintenance or stress dose following initiation of treatment; monitor for reduced serum cortisol levels and/or need for glucocorticoid dose increases in those with known hypoadrenalism
• Serum levels of phosphate, alkaline phosphatase, and the parathyroid hormone may increase after treatment; monitor these laboratory tests if abnormal
• Somatropin increases growth rate, and progression of existing scoliosis can occur in patients who experience rapid growth; somatropin has not been shown to increase the occurrence of scoliosis; monitor patients with a history of scoliosis for disease progression
• Increased risk of neoplasms
• Somatropin treatment may increase the risk of malignancy progression in patients with active malignancy
• Any preexisting malignancy should be inactive and its treatment complete before initiating somatotropin; discontinue therapy if there is evidence of recurrent activity
• An increased risk of second neoplasm reported in childhood cancer survivors treated with somatropin; the most common second neoplasms were intracranial tumors (e.g., meningiomas) in patients treated with radiation to the head for their first neoplasm
• Monitor all patients with a history of GH deficiency secondary to an intracranial neoplasm while on somatropin therapy for the progression or recurrence of the tumor
• Because pediatric patients with certain rare genetic causes of short stature have an increased risk of developing malignancies, thoroughly consider the risks and benefits of starting treatment in these patients; monitor for development of neoplasms if initiating treatment
• Monitor for increased growth or potential malignant changes of preexisting nevi; advise patients/caregivers to report marked changes in behavior, the onset of headaches, vision disturbances, and/or changes in skin pigmentation or changes in the appearance of preexisting nevi
• Intracranial hypertension
  • Intracranial hypertension (IH) with papilledema, visual changes, headache, nausea, and/or vomiting reported
  • In reported cases, IH-associated signs and symptoms rapidly resolved after discontinuing therapy or reducing the dose
  • Perform funduscopic examination routinely before initiating treatment to exclude preexisting papilledema, and periodically thereafter
  • If papilledema observed by fundoscopy, stop somatropin treatment
  • If somatropin-induced IH is confirmed, restart treatment at a lower dose once IH-associated signs and symptoms resolve
• Drug interaction overview
• Replacement glucocorticoid treatment
  • Patients treated with glucocorticoid replacement for hypoadrenalism may require an increase in their maintenance or stress dose following initiation
  • Microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD-1) is required for the conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue
  • Initiating lonapegsomatropin may result in the inhibition of 11βHSD-1 and reduced serum cortisol concentrations
  • Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment
  • Carefully adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatments to avoid both hypoadrenalism and an inhibitory effect on growth
  • Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may potentiate the growth-promoting effects of lonapegsomatropin in pediatric patients
• Cytochrome P450-metabolizing drugs
  • Carefully monitor when used in combination with drugs metabolized by cytochrome P450 (CYP450) liver enzymes
  • Limited published data indicate that somatropin treatment increases CYP450-mediated antipyrine clearance
  • Lonapegsomatropin may alter the clearance of compounds known to be metabolized by CYP450 liver enzymes
• Oral estrogen
  • Patients receiving oral estrogen replacement may require higher lonapegsomatropin dosages
  • Oral estrogens may reduce the serum insulinlike growth factor-1 response to lonapegsomatropin
• Insulin and/or other antihyperglycemic agents
  • Patients with diabetes mellitus may require dosage adjustments of their insulin and/or other antihyperglycemic agents
  • Lonapegsomatropin may decrease insulin sensitivity, particularly at higher doses

Pregnancy and Lactation

• There are no available data on use in pregnant females to evaluate a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes
• Available published data over several decades for somatropin, the active component of lonapegsomatropin, have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes
• Lactation
  • No data are available on the presence of lonapegsomatropin in human milk, its effects on the breastfed infant, or on milk production
  • High-molecular–weight therapeutic proteins, including lonapegsomatropin, are expected to have low passage into human milk and limited systemic exposure in breastfed infants
  • No adverse effects on breastfed infants have been reported with somatropin