Skytrofa

Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 9/7/2021
Skytrofa Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Skytrofa?

Skytrofa (lonapegsomatropin-tcgd) is a human growth hormone used to treat pediatric patients 1 year and older who weigh at least 11.5 kg and have growth failure due to inadequate secretion of endogenous growth hormone (GH).

What Are Side Effects of Skytrofa?

Side effects of Skytrofa include:

Dosage for Skytrofa

The recommended dose of Skytrofa is 0.24 mg/kg body weight once-weekly administered subcutaneously into the abdomen, buttock, or thigh with regular rotation of the injection sites


Skytrofa In Children

Safety and effectiveness of Skytrofa have been established in pediatric patients 1 year and older and who weigh at least 11.5 kg.

The safety and effectiveness of Skytrofa in children less than 1 year of age have not been established.

Use of somatropin in pediatric patients with Prader-Willi syndrome has been associated with reports of sudden death. Skytrofa is not indicated for the treatment of pediatric patients with growth failure due to genetically confirmed Prader-Willi syndrome.

What Drugs, Substances, or Supplements Interact with Skytrofa?
 

Skytrofa may interact with other medicines such as:

  • glucocorticoids,
  • cytochrome P450-metabolized drugs,
  • oral estrogen, and
  • insulin and/or other antihyperglycemic agents.

Tell your doctor all medications and supplements you use.


Skytrofa During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before using Skytrofa; it is unknown how it could affect a fetus. It is unknown if Skytrofa passes into breast milk.

Consult your doctor before breastfeeding.

Additional Information

Our Skytrofa (lonapegsomatropin-tcgd) for Injection, for Subcutaneous Use Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

SKYTROFA™
(lonapegsomatropin-tcgd) for injection, for subcutaneous use

DESCRIPTION

Lonapegsomatropin-tcgd is a long-acting prodrug of a human growth hormone (somatropin) produced by recombinant DNA technology using E. coli. Lonapegsomatropin-tcgd consists of a parent drug, somatropin, that is conjugated to a methoxypolyethylene glycol carrier (4 x 10 kDa mPEG) via a proprietary TransCon Linker and has a molecular weight of 63 kDa (released somatropin is 22 kDa). In vitro assay confirms the minimum potency of released somatropin is NLT 2.5 IU/mg.

SKYTROFA (lonapegsomatropin-tcgd) for injection is a sterile, preservative-free, white to off-white lyophilized powder available in a single-dose, dual-chamber, prefilled cartridge containing lonapegsomatropin-tcgd in one chamber and the diluent, Water for Injection, in the other chamber. SKYTROFA prefilled cartridge must be used with SKYTROFA Auto-Injector to provide an automatic mixing step for reconstitution prior to subcutaneous use.

After reconstitution, each prefilled cartridge delivers:

  • 0.273 mL containing 3 mg lonapegsomatropin-tcgd, succinic acid (0.32 mg), trehalose dihydrate (22.7 mg), and tromethamine for pH adjustment to 5.
  • 0.327 mL containing 3.6 mg lonapegsomatropin-tcgd, succinic acid (0.39 mg), trehalose dihydrate (27.1 mg), and tromethamine for pH adjustment to 5.
  • 0.391 mL containing 4.3 mg lonapegsomatropin-tcgd, succinic acid (0.46 mg) and trehalose dihydrate (32.5 mg) and tromethamine for pH adjustment to 5.
  • 0.473 mL containing 5.2 mg lonapegsomatropin-tcgd, succinic acid (0.56 mg) and trehalose dihydrate (39.3 mg) and tromethamine for pH adjustment to 5.
  • 0.286 mL containing 6.3 mg lonapegsomatropin-tcgd, succinic acid (0.34 mg) and trehalose dihydrate (21.2 mg) and tromethamine for pH adjustment to 5.
  • 0.345 mL containing 7.6 mg lonapegsomatropin-tcgd, succinic acid (0.41 mg) and trehalose dihydrate (25.5 mg) and tromethamine for pH adjustment to 5.
  • 0.414 mL containing 9.1 mg lonapegsomatropin-tcgd, succinic acid (0.49 mg) and trehalose dihydrate (30.6 mg) and tromethamine for pH adjustment to 5.
  • 0.5 mL containing 11 mg lonapegsomatropin-tcgd, succinic acid (0.59 mg) and trehalose dihydrate (37 mg) and tromethamine for pH adjustment to 5.
  • 0.605 mL containing 13.3 mg lonapegsomatropin-tcgd, succinic acid (0.71 mg) and trehalose dihydrate (44.8 mg) and tromethamine for pH adjustment to 5.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

QUESTION

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Skytrofa Professional Information

SIDE EFFECTS

The following important adverse reactions are described elsewhere in the labeling:

  • Increased mortality in patients with acute critical illness [see WARNINGS AND PRECAUTIONS]
  • Severe hypersensitivity [see WARNINGS AND PRECAUTIONS]
  • Increased risk of neoplasms [see WARNINGS AND PRECAUTIONS]
  • Glucose intolerance and diabetes mellitus [see WARNINGS AND PRECAUTIONS]
  • Intracranial hypertension [see WARNINGS AND PRECAUTIONS]
  • Fluid retention [see WARNINGS AND PRECAUTIONS]
  • Hypoadrenalism [see WARNINGS AND PRECAUTIONS]
  • Hypothyroidism [see WARNINGS AND PRECAUTIONS]
  • Slipped capital femoral epiphysis in pediatric patients [see WARNINGS AND PRECAUTIONS]
  • Progression of preexisting scoliosis in pediatric patients [see WARNINGS AND PRECAUTIONS]
  • Pancreatitis [see WARNINGS AND PRECAUTIONS]
  • Lipoatrophy [see WARNINGS AND PRECAUTIONS]
  • Sudden death in pediatric patients with Prader-Willi syndrome [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in clinical practice.

SKYTROFA was studied in a 52-week, open-label, active-controlled trial in 161 treatmentnaive, prepubertal pediatric patients with growth hormone deficiency (GHD) [see Clinical Studies]. The subjects ranged in age from 3.2 to 13.1 years with a mean of 8.5 years. One hundred thirty-two (82%) of the subjects were male and 29 (18%) were female. One subject was Asian, 3 were Black or African American, 152 were Caucasian, and 5 were categorized as “other.”

Table 2 shows common adverse reactions that occurred in ≥5% of patients treated with SKYTROFA in this trial.

Table 2: Adverse Reactions Occurring in ≥5% SKYTROFA-Treated Pediatric Patients and More Frequently than in Daily Somatropin-Treated Pediatric Patients (52 Weeks of Treatment)

Adverse Reactions Daily Somatropin
(N = 56) n (%)
SKYTROFA
(N = 105) n (%)
Infection, viral 6 (11%) 16 (15%)
Pyrexia 5 (9%) 16 (15%)
Cough 4 (7%) 11 (11%)
Nausea and vomiting 4 (7%) 11 (11%)
Hemorrhagea 1 (2%) 7 (7%)
Diarrhea 3 (5%) 6 (6%)
Abdominal pain 2 (4%) 6 (6%)
Arthralgia and arthritisb 1 (2%) 6 (6%)
Adverse reactions that are medically related were grouped to a single preferred term.
a Hemorrhage in the SKYTROFA treatment group included epistaxis (3), contusion (2), petechiae (1) and eye hemorrhage (1).
b Arthralgia and arthritis in the SKYTROFA treatment group included arthralgia (5) and reactive arthritis (1).

Laboratory Tests

More SKYTROFA-treated patients shifted from normal baseline levels to elevated phosphate and alkaline phosphatase levels at the end of the trial compared to the daily somatropin group (44.2% vs. 30.2% and 19.2% vs. 9.4%, respectively); these laboratory changes occurred intermittently [see WARNINGS AND PRECAUTIONS].

Immunogenicity

As with all therapeutic proteins, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to SKYTROFA with the incidence of antibodies to other products may be misleading.

Anti-lonapegsomatropin-tcgd antibodies were evaluated in samples collected every 3 months in phase 3 trials in pediatric patients with GHD receiving lonapegsomatropin-tcgd. Mean duration of exposure to SKYTROFA was 70.2 weeks. Of the 304 patients with post-baseline assessments, 19 (6.3%) showed detectable binding antibodies to lonapegsomatropin-tcgd at any time. No apparent correlation of anti-lonapegsomatropin-tcgd antibodies to adverse events or loss of efficacy was observed. No neutralizing antibodies to SKYTROFA were detected.

DRUG INTERACTIONS

Table 3 includes a list of drugs with clinically important drug interactions when administered concomitantly with SKYTROFA and instructions for preventing or managing them.

Table 3: Clinically Important Drug Interactions with SKYTROFA

Replacement Glucocorticoid Treatment
Clinical Impact: Microsomal enzyme 1ip-hydroxysteroid dehydrogenase type 1 (11βHSD-1) is required for conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue. Somatropin inhibits 11βHSD-1. Consequently, individuals with untreated growth hormone deficiency (GHD) have relative increases in 11βHSD-1 and serum cortisol. Initiation of SKYTROFA may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations.
Intervention: Patients treated with glucocorticoid replacement for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of SKYTROFA [see WARNINGS AND PRECAUTIONS]
Examples Cortisone acetate and prednisone may be affected more than others because conversion of these drugs to their biologically active metabolites is dependent on the activity of 11βHSD-1.
Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment
Clinical Impact: Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may attenuate the growth-promoting effects of SKYTROFA in pediatric patients.
Intervention: Carefully adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatments to avoid both hypoadrenalism and an inhibitory effect on growth.
Cytochrome P450-Metabolized Drugs
Clinical Impact: Limited published data indicate that somatropin treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. SKYTROFA may alter the clearance of compounds known to be metabolized by CYP450 liver enzymes.
Intervention: Careful monitoring is advisable when SKYTROFA is administered in combination with drugs metabolized by CYP450 liver enzymes.
Oral Estrogen
Clinical Impact: Oral estrogens may reduce the serum insulin-like growth factor-1 (IGF-1) response to SKYTROFA.
Intervention: Patients receiving oral estrogen replacement may require higher SKYTROFA dosages.
Insulin and/or Other Antihyperglycemic Agents
Clinical Impact: Treatment with SKYTROFA may decrease insulin sensitivity, particularly at higher doses.
Intervention: Patients with diabetes mellitus may require adjustment of their doses of insulin and/or other antihyperglycemic agents [see WARNINGS AND PRECAUTIONS].

Drug Abuse And Dependence

Controlled Substance

SKYTROFA is a prodrug of somatropin. Somatropin is not a controlled substance.

Abuse

Inappropriate use of somatropin may result in significant negative health consequences.

Dependence

Somatropin is not associated with drug related withdrawal adverse reactions.

Read the entire FDA prescribing information for Skytrofa (Lonapegsomatropin-tcgd for Injection)

SLIDESHOW

Digestive Disorders: Common Misconceptions See Slideshow

© Skytrofa Patient Information is supplied by Cerner Multum, Inc. and Skytrofa Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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