| Clinically unstable APL patients are especially at risk and will require more frequent monitoring of electrolyte and glycaemia levels as well as more frequent haematologic, hepatic, renal and coagulation parameter tests.Leukocyte Activation Syndrome (APL Differentiation Syndrome): Twenty-five percent of patients with APL treated with TRISENOX have experienced symptoms similar to a syndrome called the retinoic-acid-acute promyelocytic leukaemia (RA-APL) or APL differentiation syndrome, characterised by fever, dyspnoea, weight gain, pulmonary infiltrates and pleural or pericardial effusions, with or without leukocytosis. This syndrome can be fatal. The management of the syndrome has not been fully studied, but high-dose steroids have been used at the first suspicion of the APL differentiation syndrome and appear to mitigate signs and symptoms. At the first signs that could suggest the syndrome (unexplained fever, dyspnoea and/or weight gain, abnormal chest auscultatory findings or radiographic abnormalities), high-dose steroids (dexamethasone 10 mg intravenously twice a day) must be immediately initiated, irrespective of the leukocyte count and continued for at least 3 days or longer until signs and symptoms have abated. The majority of patients do not require termination of TRISENOX therapy during treatment of the APL differentiation syndrome. It is recommended that chemotherapy not be added to treatment with steroids since there is no experience with administration of both steroids and chemotherapy during treatment of the leukocyte activation syndrome due to TRISENOX. Post-marketing experience suggests that a similar syndrome may occur in patients with other types of malignancy. Monitoring and management for these patients should be as described above.Electrocardiogram (ECG) Abnormalities: Arsenic trioxide can cause QT interval prolongation and complete atrioventricular block. QT prolongation can lead to a torsade de pointes-type ventricular arrhythmia, which can be fatal. Previous treatment with anthracyclines may increase the risk of QT prolongation. The risk of torsade de pointes is related to the extent of QT prolongation, concomitant administration of QT prolonging medicinal products (such as class Ia and III antiarrythmics (e.g. quinidine, amiodarone, sotalol, dofetilide), antipsychotics (e.g. thioridazine), antidepressants (e.g. amitriptyline), some macrolides (e.g. erythromycin), some antihistamines (e.g. terfenadine and astemizole), some quinolone antibiotics (e.g. sparfloxacin), and other individual drugs known to increase QT interval (e.g. cisapride)), a history of torsade de pointes, pre-existing QT interval prolongation, congestive heart failure, administration of potassium-wasting diuretics, amphotericin B or other conditions that result in hypokalemia or hypomagnesaemia. In clinical trials, 40% of patients treated with TRISENOX experienced at least one QT corrected (QTc) interval prolongation greater than 500 msec. Prolongation of the QTc was observed between 1 and 5 weeks after TRISENOX infusion, and then returned to baseline by the end of 8 weeks after TRISENOX infusion. One patient (receiving multiple, concomitant medicinal products, including amphotericin B) had asymptomatic torsade de pointes during induction therapy for relapsed APL with arsenic trioxide.ECG and Electrolyte Monitoring Recommendations: Prior to initiating therapy with TRISENOX, a 12-lead ECG must be performed and serum electrolytes (potassium, calcium, and magnesium) and creatinine must be assessed; preexisting electrolyte abnormalities must be corrected and, if possible, medicinal products that are known to prolong the QT interval must be discontinued. Patients with risk factors of QTc prolongation or risk factors of torsade de pointes should be monitored with continuous cardiac monitoring (ECG). For QTc greater than 500 msec, corrective measures must be completed and the QTc reassessed with serial ECGs prior to considering using TRISENOX. During therapy with TRISENOX, potassium concentrations must be kept above 4 mEq/l and magnesium concentrations must be kept above 1.8 mg/dl. Patients who reach an absolute QT interval value> 500 msec must be reassessed and immediate action must be taken to correct concomitant risk factors, if any, while the risk/benefit of continuing versus suspending TRISENOX therapy must be considered. If syncope, rapid or irregular heartbeat develops, the patient must be hospitalised and monitored continuously, serum electrolytes must be assessed, TRISENOX therapy must be temporarily discontinued until the QTc interval regresses to below 460 msec, electrolyte abnormalities are corrected, and the syncope and irregular heartbeat cease. There are no data on the effect of TRISENOX on the QTc interval during the infusion. Electrocardiograms must be obtained twice weekly, and more frequently for clinically unstable patients, during induction and consolidation.Dose Modification: Treatment with TRISENOX must be interrupted, adjusted, or discontinued before the scheduled end of therapy at any time that a toxicity grade 3 or greater on the National Cancer Institute Common Toxicity Criteria, Version 2 is observed and judged to be possibly related to TRISENOX treatment. Patients who experience such reactions that are considered TRISENOX related must resume treatment only after resolution of the toxic event or after recovery to baseline status of the abnormality that prompted the interruption. In such cases, treatment must resume at 50% of the preceding daily dose. If the toxic event does not recur within 3 days of restarting treatment at the reduced dose, the daily dose can be escalated back to 100% of the original dose. Patients who experience a recurrence of toxicity must be removed from treatment.Laboratory tests: The patient's electrolyte and glycaemia levels, as well as haematologic, hepatic, renal and coagulation parameter tests must be monitored at least twice weekly, and more frequently for clinically unstable patients during the induction phase and at least weekly during the consolidation phase. Patients with renal impairment: Since limited data are available across all renal impairment groups, caution is advised in the use of TRISENOX in patients with renal impairment. The experience in patients with severe renal impairment is insufficient to determine if dose adjustment is required.The use of TRISENOX in patients on dialysis has not been studied. Patients with hepatic impairment:Since limited data are available across all hepatic impairment groups, caution is advised in the use of TRISENOX in patients with hepatic impairment. The experience in patients with severe hepatic impairment is insufficient to determine if dose adjustment is required.Elderly patients: There is limited clinical data on the use of TRISENOX in the elderly population. Caution is needed in these patients.Hyperleukocytosis: Treatment with TRISENOX has been associated with the development of hyperleukocytosis ( 10 x 103/μl) in some patients. There did not appear to be a relationship between baseline white blood cell (WBC) counts and development of hyperleukocytosis nor did there appear to be a correlation between baseline WBC count and peak WBC counts. Hyperleukocytosis was never treated with additional chemotherapy and resolved on continuation of TRISENOX. WBC counts during consolidation were not as high as during induction treatment and were < 10 x 103/μl, except in one patient who had a WBC count of 22 x 103/μl during consolidation. Twenty patients (50%) experienced leukocytosis; however, in all these patients, the WBC count was declining or had normalized by the time of bone marrow remission and cytotoxic chemotherapy or leukopheresis was not required. | |