Drug Interactions between Akynzeo for Injection and ceritinib

MONITOR CLOSELY: Ceritinib can cause concentration-dependent prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. Across the development program for ceritinib, one of 304 patients (less than 1%) treated with dosages ranging from 50 mg to 750 mg was found to have a QTc greater than 500 msec and 10 patients (3%) had an increase from baseline QTc greater than 60 msec. A central tendency analysis of the QTc data at average steady-state concentrations predicted a QTc increase of 16 msec at the 750 mg dose. A pharmacokinetic/pharmacodynamic analysis suggested concentration-dependent QTc prolongation. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia, hypocalcemia). Moreover, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Caution is recommended if ceritinib is used in combination with other drugs that can prolong the QT interval. ECG and serum electrolytes, including potassium, magnesium and calcium, should be monitored before starting ceritinib therapy and periodically during treatment. Ceritinib should not be started if baseline QTc is greater than 500 msec. Likewise, treatment should be withheld in patients who develop a QTc interval greater than 500 msec on at least 2 separate ECGs until the QTc interval is less than 481 msec or recovery to baseline (if the QTc interval is greater than or equal to 481 msec), then resume ceritinib with a 150 mg dosage reduction. Permanently discontinue ceritinib therapy if QTc prolongation develops in combination with torsade de pointes or polymorphic ventricular tachycardia or signs and symptoms of serious arrhythmia. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

MONITOR: Coadministration with inhibitors of CYP450 3A4 may increase the plasma concentrations of ceritinib, which is a substrate of the isoenzyme. In 19 healthy subjects, administration of a single 450 mg dose of ceritinib with the potent CYP450 3A4 inhibitor ketoconazole (200 mg twice daily for 14 days) increased ceritinib peak plasma concentration (Cmax) by 22% and systemic exposure (AUC) by 2.9-fold. The steady-state AUC of ceritinib at reduced doses after coadministration with ketoconazole 200 mg twice daily for 14 days was predicted by simulations to be similar to the steady-state AUC of ceritinib administered alone. Because ceritinib is associated with concentration-dependent prolongation of the QT interval, increased levels may potentiate the risk of ventricular arrhythmias such as torsade de pointes and sudden death. Other, more common side effects such as diarrhea, nausea, vomiting, abdominal pain, hyperglycemia, and bradycardia may also increase.

MANAGEMENT: Caution is advised if ceritinib is prescribed with CYP450 3A4 inhibitors. Pharmacologic response to ceritinib should be monitored more closely whenever a CYP450 3A4 inhibitor is added to or withdrawn from therapy, and the ceritinib dosage adjusted as necessary. Patients should have periodic ECGs and be monitored for arrhythmias when QT interval is prolonged. A QTc interval exceeding 500 msec on at least two separate ECGs will require suspension of ceritinib therapy and immediate action to correct any concomitant risk factors before resuming treatment with a 150 mg dosage reduction. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope. Following discontinuation of the CYP450 3A4 inhibitor, ceritinib therapy should be resumed at the dosage that was taken prior to initiating the CYP450 3A4 inhibitor if an adjustment was made.