Refractory acute promyelocytic leukemia successfully treated with combination therapy of arsenic trioxide and tamibarotene: A case report

A 40-year-old male developed refractory acute promyelocytic leukemia (APL) after various treatments including all-trans retinoic acid, tamibarotene, arsenic trioxide (As(2)O(3)), conventional chemotherapy, and autologous peripheral blood stem cell transplantation. We attempted to use both tamibarotene and As(2)O(3) as a combination therapy, and he achieved molecular complete remission. Grade 2 prolongation of the QTc interval on the electrocardiogram was observed during the therapy. The combination therapy of As(2)O(3) and tamibarotene may be effective and tolerable for treating refractory APL cases who have no treatment options, even when they have previously been treated with tamibarotene and As(2)O(3)as a single agent.