Purpose: Little experience exists with the use of arsenic trioxide in the treatment of recurrent, all-trans retinoic acid (ATRA)-resistant, acute promyelocytic leukemia (APL). The authors report a patient with multiply recurrent APL treated with arsenic trioxide (As2O3), which was administered as recommended in the protocol from the People' s Republic of China. The results of this treatment and its toxicity are discussed. The available literature on arsenic therapy is reviewed.
Patients and methods: The patient was a 15-year-old African-American girl with APL that had resisted conventional chemotherapy, ATRA therapy followed by autologous peripheral stem cell transplant, and a second course of ATRA induction therapy administered for relapse after transplant. The patient was treated with 10 mg As2O3 intravenously for 28 days. After a 4-week break, she received a second 28-day course of As2O3 therapy.
Results: After completion of the first 28-day course of As2O3 treatment, morphologic and cytogenetic remission occurred. Reverse-transcription polymerase chain reaction demonstrated persistence of the PML-RARalpha fusion transcript. After the second course of As2O3, the patient had a complete remission by morphologic, cytogenetic, and molecular criteria. Approximately 6 months after the end of two courses of As2O3 therapy, the patient again underwent relapse. An additional course of As2O3 achieved a morphologic, although not a cytogenetic or molecular, remission.
Conclusions: As2O3 therapy produced remission in a patient with multiply relapsed, ATRA-resistant APL. Toxic side effects were minimal. The patient underwent relapse 6 months after this therapy. Further investigation will be necessary to determine the proper role of As2O3 therapy in patients with APL.