Arsenic Trioxide With or Without Tretinoin

For children with recurrent APL, the use of arsenic trioxide as a single agent or in regimens including tretinoin should be considered, depending on the therapy given during first remission. Arsenic trioxide is an active agent in adult patients with recurrent APL, with approximately 85% to 94% of patients achieving remission after treatment with this agent.[8-13] More limited data in children suggest that children with relapsed APL have a response to arsenic trioxide that is similar to that of adults.[8,10,13,14] Arsenic trioxide is well tolerated in children with relapsed APL, with a toxicity profile similar to that of adults.[8,13]

Arsenic trioxide is capable of inducing remissions in patients who relapse after having received arsenic trioxide with or without other agents during initial therapy.[13,15] However, APL cells may develop arsenic trioxide resistance when they acquire somatic variants in the PML domain of the PML::RARA fusion oncogene.[16]

Because arsenic trioxide causes QT-interval prolongation that can lead to life-threatening arrhythmias,[17] it is essential to monitor electrolytes closely in patients receiving arsenic trioxide and to maintain potassium and magnesium values at midnormal ranges.[18]