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Vandetanib (Vandetanib) - Warnings and Precautions

 
 



BOXED WARNING SECTION

WARNING: QT PROLONGATION, TORSADES DE POINTES, AND SUDDEN DEATH

Vandetanib can prolong the QT interval. Torsades de pointes and sudden death have been reported in patients receiving vandetanib. Vandetanib should not be used in patients with hypocalcemia, hypokalemia, hypomagnesemia, or long QT syndrome. Hypocalcemia, hypokalemia and/or hypomagnesemia must be corrected prior to vandetanib administration and should be periodically monitored. Drugs known to prolong the QT interval should be avoided. If a drug known to prolong the QT interval must be administered, more frequent ECG monitoring is recommended. Given the half-life of 19 days, ECGs should be obtained to monitor the QT at baseline, at 2-4 weeks and 8-12 weeks after starting treatment with vandetanib and every 3 months thereafter. Following any dose reduction for QT prolongation, or any dose interruptions greater than 2 weeks, QT assessment should be conducted as described above. Because of the 19-day half-life, adverse reactions including a prolonged QT interval may not resolve quickly. Monitor appropriately. Only prescribers and pharmacies certified through the vandetanib REMS education program are able to prescribe and dispense vandetanib [see Warnings and Precautions].

 

WARNINGS AND PRECAUTIONS

QT Prolongation and Torsades de Pointes

Vandetanib can prolong the QT interval in a concentration-dependent manner [see Clinical Pharmacology]. Torsades de pointes, ventricular tachycardia and sudden deaths have been reported in patients administered vandetanib.

Vandetanib treatment should not be started in patients whose QTcF interval is greater than 450 ms. Vandetanib should not be given to patients who have a history of Torsades de pointes, congenital long QT syndrome, bradyarrhythmias or uncompensated heart failure. Vandetanib has not been studied in patients with ventricular arrhythmias or recent myocardial infarction. Vandetanib exposure is increased in patients with impaired renal function. The starting dose should be reduced to 200 mg in patients with moderate to severe renal impairment and QT interval should be monitored closely.

An ECG and levels of serum potassium, calcium, magnesium and TSH should be obtained at baseline, at 2-4 weeks and 8-12 weeks after starting treatment with vandetanib and every 3 months thereafter. Electrolytes and ECGs may require more frequent monitoring in case of diarrhea. Following any dose reduction for QT prolongation, or any dose interruptions greater than 2 weeks, QT assessments should be conducted as described above. Serum potassium levels should be maintained at 4 mEq/L or higher (within normal range) and serum magnesium and serum calcium should be kept within normal range to reduce the risk of electrocardiogram QT prolongation.

Avoid using vandetanib with drugs known to prolong the electrocardiogram QT interval [see Warnings and Precautions and Drug Interactions]. If such drugs are given to patients already receiving vandetanib and no alternative therapy exists, ECG monitoring of the QT interval should be performed more frequently.

Patients who develop a QTcF greater than 500 ms should stop taking vandetanib until QTcF returns to less than 450 ms. Dosing of vandetanib can be resumed at a reduced dose [see Dosage and Administration].

Skin Reactions and Stevens-Johnson Syndrome

Severe skin reactions (including Stevens-Johnson syndrome), some leading to death, have been reported with vandetanib. Treatment of severe skin reactions has included systemic corticosteroids and permanent discontinuation of vandetanib. Mild to moderate skin reactions may manifest as rash, acne, dry skin, dermatitis, pruritis and other skin reactions (including photosensitivity reactions and palmar-plantar erythrodysesthesia syndrome). Mild to moderate skin reactions have been treated with topical and systemic corticosteroids, oral antihistamines, and topical and systemic antibiotics. If CTCAE grade 3 or greater skin reactions occur, vandetanib treatment should be stopped until improved. Upon improvement, consideration should be given to continuing treatment at a reduced dose or permanent discontinuation of vandetanib. [see Dosage and Administration]

Photosensitivity reactions are increased with vandetanib. Patients should be advised to wear sunscreen and protective clothing when exposed to the sun. Due to the long half-life of vandetanib, protective clothing and sunscreen should continue for 4 months after discontinuation of treatment.

Interstitial Lung Disease

Interstitial Lung Disease (ILD) or pneumonitis has been observed with vandetanib and deaths have been reported. Consider a diagnosis of ILD in patients presenting with non-specific respiratory signs and symptoms such as hypoxia, pleural effusion, cough, or dyspnea, and in whom infectious, neoplastic, and other causes have been excluded by means of appropriate investigations. Advise patients to report promptly any new or worsening respiratory symptoms.

Patients who develop radiological changes suggestive of ILD and have few or no symptoms may continue vandetanib therapy with close monitoring at the discretion of the treating physician.

If symptoms are moderate, consider interrupting therapy until symptoms improve. The use of corticosteroids and antibiotics may be indicated.

For cases where symptoms of ILD are severe, discontinue vandetanib therapy and the use of corticosteroids and antibiotics may be indicated until clinical symptoms resolve. Even upon resolution of severe ILD, permanent discontinuation of vandetanib should be considered.

Ischemic Cerebrovascular Events

Ischemic cerebrovascular events have been observed with vandetanib and some cases have been fatal. In the randomized medullary thyroid cancer (MTC) study, ischemic cerebrovascular events were observed more frequently with vandetanib compared to placebo (1.3% compared to 0%) and no deaths were reported. The safety of resumption of vandetanib therapy after resolution of an ischemic cerebrovascular event has not been studied. Discontinue vandetanib in patients who experience a severe ischemic cerebrovascular event.

Hemorrhage

Serious hemorrhagic events, which in some cases were fatal, have been observed with vandetanib. There were no fatal bleeding events in the randomized MTC study. Three patients died of fatal bleeding events while on vandetanib therapy in clinical studies. Do not administer vandetanib to patients with recent history of hemoptysis of ≥ 1/2 teaspoon of red blood. Discontinue vandetanib in patients with severe hemorrhage.

Heart Failure

Heart failure has been observed with vandetanib and some cases have been fatal. Discontinuation of vandetanib may be necessary in patients with heart failure. Heart failure may not be reversible upon stopping vandetanib. Monitor for signs and symptoms of heart failure.

Diarrhea

Diarrhea was observed in patients who received vandetanib. Routine anti-diarrheal agents are recommended. Diarrhea may cause electrolyte imbalances. Since QT prolongation is seen with vandetanib, serum electrolytes and ECGs should be carefully monitored in patients with diarrhea. [see Warnings and Precautions] If severe diarrhea develops, vandetanib treatment should be stopped until diarrhea improves. Upon improvement, treatment with vandetanib should be resumed at a reduced dose [see Dosage and Administration].

Hypothyroidism

In the randomized MTC study where 90% of the patients enrolled had prior thyroidectomy, increases in the dose of the thyroid replacement therapy were required in 49% of the patients randomized to vandetanib compared to 17% of the patients randomized to placebo. Thyroid-stimulating hormone (TSH) should be obtained at baseline, at 2 to 4 weeks and 8 to 12 weeks after starting treatment with vandetanib and every 3 months thereafter. If signs or symptoms of hypothyroidism occur, thyroid hormone levels should be examined and thyroid replacement therapy should be adjusted accordingly.

Hypertension

Hypertension, including hypertensive crisis, has been observed with vandetanib. All patients should be monitored for hypertension and it should be controlled as appropriate. Dose reduction or interruption may be necessary. If high blood pressure cannot be controlled, vandetanib should not be restarted [see Dosage and Administration].

Reversible posterior leukoencephalopathy syndrome

Reversible posterior leukoencephalopathy syndrome (RPLS), a syndrome of subcortical vasogenic edema diagnosed by an MRI of the brain, has been observed with vandetanib. This syndrome should be considered in any patient presenting with seizures, headache, visual disturbances, confusion or altered mental function. In clinical studies, three of four patients who developed RPLS while taking vandetanib, including one pediatric patient, also had hypertension. Discontinuation of vandetanib treatment in patients with RPLS should be considered.

Drug Interactions

The administration of vandetanib with agents that are strong CYP3A4 inducers should be avoided [see Dosage and Administration and Drug Interactions].

The administration of vandetanib with anti-arrhythmic drugs (including, but not limited to amiodarone, disopyramide, procainamide, sotalol, dofetilide) and other drugs that may prolong the QT interval (including but not limited to cloroquine, clarithromycin, dolasetron, granisetron, haloperidol, methadone, moxifloxacin, and pimozide) should be avoided [see Drug Interactions].

Renal Impairment

Vandetanib exposure is increased in patients with impaired renal function. The starting dose should be reduced to 200 mg in patients with moderate to severe renal impairment and QT interval should be monitored closely. There is no information available for patients with end-stage renal disease requiring dialysis. [see Boxed Warning, Dosage and Administration and Use in Specific Populations]

Hepatic Impairment

Vandetanib is not recommended for use in patients with moderate and severe hepatic impairment, as safety and efficacy have not been established. [see Dosage and Administration]

Use in Pregnancy

Vandetanib can cause fetal harm when administered to a pregnant woman. There are no adequate and well-controlled studies in pregnant women using vandetanib. In nonclinical studies in rats, vandetanib was embryotoxic, fetotoxic, and teratogenic, at exposures equivalent to or lower than those expected at the recommended human dose of 300 mg/day. As expected from its pharmacological actions, vandetanib has shown significant effects on all stages of female reproduction in rats.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Women of childbearing potential should be advised to avoid becoming pregnant during treatment with vandetanib. Women should be advised that they must use effective contraception to prevent pregnancy during treatment and for at least four months following the last dose of vandetanib [see Use in Specific Populations].

Vandetanib REMS (Risk Evaluation and Mitigation Strategy) Program

Because of the risk of QT prolongation, Torsades de pointes, and sudden death, vandetanib is available only through a restricted distribution program called Vandetanib REMS Program. Only prescribers and pharmacies certified with the program are able to prescribe and dispense vandetanib.

An overview of the requirements for prescribers and pharmacies is included below.

  • To be certified, prescribers must review the educational materials, agree to comply with the REMS requirements and enroll in the program.
  • To be certified, pharmacies that dispense vandetanib must enroll in the program, train their pharmacy staff to verify that each prescription is written by a certified prescriber before dispensing to a patient, and agree to comply with the REMS requirements.

To learn about the specific REMS requirements and to enroll in the Vandetanib REMS Program call 1-800-236-9933 or visit www.vandetanibrems.com.

USE IN SPECIFIC POPULATIONS

Pregnancy

Pregnancy Category D[see Warnings and Precautions].

Vandetanib can cause fetal harm when administered to a pregnant woman. There are no adequate and well-controlled studies of vandetanib in pregnant women. Vandetanib is embryotoxic, fetotoxic, and teratogenic to rats, at exposures equivalent to or lower than those expected at the recommended human dose of 300 mg/day. When vandetanib was administered to female rats prior to mating and through the first week of pregnancy, there were increases in pre-implantation loss and post-implantation loss resulting in a significant reduction in the number of live embryos. This dose administered to rats during organogenesis, caused an increase in post-implantation loss including embryofetal death. Vandetanib caused total litter loss when administered at a dose of 25 mg/kg/day during organogenesis until expected parturition. When administered during organogenesis, vandetanib doses of 1, 10 and 25 mg/kg/day (approximately 0.03, 0.4, and 1.0 times respectively, the Cmax in patients with cancer at the recommended human dose) caused malformations of the heart vessels and delayed ossification of the skull, vertebrae and sternum, indicating delayed fetal development. A no effect level for these malformations was not identified in this study. In a rat pre- and post-natal development study, at doses producing maternal toxicity (1 and 10 mg/kg/day) during gestation and/or lactation, vandetanib, decreased pup survival, and/or reduced post-natal pup growth. Reduced post-natal pup growth was associated with a delay in physical development.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Women of childbearing potential should be advised to avoid pregnancy while taking vandetanib and for at least four months following the last dose of vandetanib.

Nursing Mothers

In nonclinical studies, vandetanib was excreted in rat milk and found in plasma of pups following dosing to lactating rats. Vandetanib transfer in breast milk resulted in relatively constant exposure in pups due to the long half-life of the drug. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from vandetanib, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

Safety and efficacy of vandetanib in pediatric patients have not been established.

Geriatric Use

In total, 18% of medullary thyroid cancer patients treated with vandetanib were age 65 years or older, and 3% were 75 years and older. No overall differences in safety and efficacy were observed between elderly and younger patients. No adjustment in starting dose is required for patients over 65 years of age. There are limited data for patients over the age of 75 years.

Renal Impairment

The pharmacokinetics of vandetanib were evaluated after a single dose of 800 mg in subjects with mild (n = 6), moderate (n = 8), and severe (n = 6) renal impairment and normal (n = 10) renal function. Subjects with mild renal impairment had comparable mean AUC and clearance values to those with normal renal function. In subjects with moderate and severe renal impairment, the average AUC of vandetanib increased by 39% and 41%, respectively, compared to patients with normal renal function.

The starting dose should be reduced to 200 mg in patients with moderate and severe renal impairment [see Dosage and Administration and Warning and Precautions].

Hepatic Impairment

The pharmacokinetics of vandetanib were evaluated after a single dose of 800 mg in subjects with mild (n = 8), moderate (n = 7), and severe (n = 6) hepatic impairment and normal hepatic function (n = 5). Subjects with mild (Child-Pugh class A), moderate (Child-Pugh class B), and severe (Child-Pugh class C) hepatic impairment had comparable mean AUC and clearance values to those with normal hepatic function.

There are limited data in patients with liver impairment (serum bilirubin greater than 1.5 times the upper limit of normal). Vandetanib is not recommended for use in patients with moderate and severe hepatic impairment, as safety and efficacy have not been established. [see Dosage and Administration and Warnings and Precautions].

Page last updated: 2011-04-13

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