A Study for Improving the Outcome of Childhood Acute Promyeloid Leukemia

Outcome of acute promyelocytic leukemia (APL) has greatly improved since the introduction of all-trans-retinoic acid (ATRA). Treatment with ATRA and anthracycline-based chemotherapy (ATRA + chemotherapy) decreases relapses of the disease as well as early hemorrhagic deaths. Nowadays patients with APL have an event-free survival (EFS) of up to 80%. However, there remains a subset of the patients in whom the disease relapses. Recently, a randomized prospective study showed that the addition of ATO to "ATRA + chemotherapy" treatment protocol had a significantly higher EFS in patients with APL than those treated with "ATRA + chemotherapy" protocol. The patients treated with "ATO + ATRA + chemotherapy" had a five years EFS of 89.2%. Moreover, a recent study showed that Indigo naturalis formula (RIF), a traditional Chinese medicine with tetraarsenic tetrasulfide (As4S4), indirubin, and tanshinone IIA as major active ingredients, yielded synergy in the treatment of a murine APL model in vivo and in the induction of APL cell differentiation in vitro . It is about 20 years since RIF was used to treat ALP in China. Clinical studies showed that this agent was effective against APL. Compared to ATO, RIF is relatively inexpensive and can be taken orally, resulting in reducing the number of hospital days and the treatment cost. However, there is no report comparing treatment outcomes of "ATO + ATRA + chemotherapy" and "RIF + ATRA + chemotherapy" protocols in children with APL so far. For this purpose, therefore, investigators are going to conduct a multicenter and randomized prospective study in children with APL.