General

High Alert Medication: This medication bears a heightened risk of causing significant patient harm when it is used in error.

Genetic Implications:

Pronunciation:
gil-te-ri-ti-nib

Trade Name(s)

• Xospata

Ther. Class.

antineoplastics

Pharm. Class.

kinase inhibitors

Indications

  Relapsed or refractory acute myeloid leukemia (AML) with a FMS-like tyrosine kinase 3 (FLT3) mutation.

Action

Inhibits FLT3 receptor signaling and cell proliferation and induces apoptosis in leukemic cells expressing FLT3-ITD.

Therapeutic Effect(s):

Improved survival.

Pharmacokinetics

Absorption: Absorption ↓ and delayed with high-fat food.

Distribution: Extensively distributed to tissues.

Metabolism and Excretion: Primarily metabolized via the liver by the CYP3A4 isoenzyme. Primarily excreted in the feces (64.5%); 16.4% excreted in urine.

Half-life: 113 hr.

TIME/ACTION PROFILE (plasma concentrations)

Contraindication/Precautions

Contraindicated in:

• Hypersensitivity;
• OB:   Pregnancy;
• Lactation: Lactation.

Use Cautiously in:

• Electrolyte abnormalities;
• Rep:  Women of reproductive potential and men with female partners of reproductive potential;
• Pedi:  Safety and effectiveness not established in children.

Adverse Reactions/Side Effects

CV: hypotension, peripheral edema, QT interval prolongation

Derm: rash

F and E: hypophosphatemia, hypocalcemia, hyponatremia

GI: abdominal pain, constipation, ↑ liver enzymes, metallic taste, mucositis, nausea, PANCREATITIS, vomiting, diarrhea

GU: renal impairment

Hemat: differentiation syndrome

Metabolic: hypertriglyceridemia

MS: arthralgia, myalgia, ↑ CK

Neuro: dizziness, fatigue, headache, insomnia, neuropathy, POSTERIOR REVERSIBLE ENCEPHALOPATHY SYNDROME (PRES)

Resp: cough, dyspnea

Misc: fever

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

• Combined  P-glycoprotein (P-gp) and strong CYP3A inducers  may ↓ levels and effectiveness; avoid concurrent use.
•  Strong CYP3A inhibitors  may ↑ levels and risk of toxicity; consider an alternative therapy that does not inhibit CYP3A.
• May ↓ levels of  escitalopram,  fluoxetine, and  sertraline ; avoid concurrent use.
• May ↑ levels and toxicity of  P-gp substrates,  breast cancer resistant protein substrates, and  organic cation transporter 1 substrates.

Route/Dosage

PO (Adults): 120 mg once daily; continue treatment for ≥6 mo (provided that disease progression and/or unacceptable toxicity do not occur) to determine clinical response.

Availability

Tablets: 40 mg

Assessment

• Monitor for signs and symptoms of differentiation syndrome (fever, dyspnea, pulmonary infiltrates, pleural effusion, pericardial effusion, hypotension, rapid weight gain, peripheral edema, renal dysfunction) during therapy. If suspected, administer systemic corticosteroids (dexamethasone 10 mg IV every 12 hr or equivalent) and begin hemodynamic monitoring until symptom resolution. Administer corticosteroids for ≥3 days and taper after symptoms resolve. If severe signs and symptoms persist for >48 hr after starting corticosteroids, hold gilteritinib until signs and symptoms are no longer severe.
• Monitor for signs and symptoms of PRES (impaired consciousness, convulsions, visual disturbances [including blindness], loss of motor function, movement disorders, psychiatric disturbances, papilledema, visual impairment). Discontinue therapy if PRES develops. Usually reversible with discontinuation of gilteritinib.
• Assess ECG before starting, on Days 8 and 15 of Cycle 1, and before starting next two subsequent cycles.  If QTc interval >500 msec,  hold dose and ↓ to 80 mg once daily when QTc interval returns to within 30 msec of baseline or ≤480 msec.  If QTc interval ↑ by >30 msec on Day 8 of Cycle 1,  confirm with ECG on Day 9. If confirmed, consider dose ↓ to 80 mg once daily. Hypokalemia and hypomagnesemia may ↑ risk of QT interval prolongation; monitor potassium and magnesium levels and correct before and during therapy.
• Monitor for signs and symptoms of pancreatitis (severe abdominal pain) during therapy.  If symptoms occur,  hold gilteritinib and resume at 80 mg once daily when symptoms resolved.

Lab Test Considerations:

Obtain a negative pregnancy test within 7 days before starting therapy.

•  Selection of patients is based on the presence of FLT3 mutations in blood or bone marrow. FDA-approved tests for detection of FLT3 mutation are available at http://www.fda.gov/CompanionDiagnostics.
• Assess CBC and blood chemistries, including CK, before starting gilteritinib, at least once weekly for 1st mo, once every other wk for 2nd mo, and monthly for duration of therapy.

Implementation

• PO Administer once daily at the same time each day without regard to food.  DNC: Swallow tablet whole; do not crush, break, or chew. 

Patient/Family Teaching

• Instruct patient to take gilteritinib as directed. Take missed doses as soon as remembered on the same day and ≥12 hr before next scheduled dose; do not double doses. Advise patient to read  Medication Guide  before starting therapy and with each Rx refill in case of changes.
• Advise patient to notify health care provider immediately if signs or symptoms of differentiation syndrome (fever, cough, dizziness or light-headedness, rapid weight gain, trouble breathing, swelling of arms or legs, rash, decreased urination) or PRES (headache, decreased alertness, confusion, reduced eyesight, blurred vision, other visual problems) occur.
• Advise patient to notify health care provider immediately if signs or symptoms of QT interval prolongation (dizziness, light-headedness, feeling faint) or pancreatitis occur.
• Instruct patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care provider before taking other medications.
• Rep:  May cause fetal harm. Advise women of reproductive potential to use effective contraception during and for ≥6 mo after last dose and to avoid breastfeeding during and for ≥2 mo after last dose of gilteritinib. Advise men with female partners of reproductive potential to use effective contraception during and for ≥4 mo after last dose.

Evaluation/Desired Outcomes

Improved survival in AML.