In recent years, the prognosis of pediatric relapsed ALL patients has improved, but the 5-year OS of patients with first recurrence is still less than 50%. A number of in vitro studies have shown that arsenic trioxide (ATO) can selectively inhibit the growth and induce apoptosis in a variety of leukemia cell lines, suggesting that ATO as a synergist combined with other common chemotherapy drugs may provide a new target for the treatment of relapsed ALL. Realgar Indigo naturalis formula is a compound traditional Chinese medicine preparation developed in China. The main component of realgar is arsenic tetrasulfide (As4S4), which can produce similar pharmacological effects to ATO. Based on the R3 protocol, this study plans to perform a double-blind randomized controlled trial, and to randomly combine compound Huangdai tablets with compound Huangdai tablets in the treatment of intermediate and high risk ALL children, in order to improve the MRD negative rate after induction therapy in this group of children, which may provide a new method for the clinical treatment of relapsed ALL.

In recent years, the prognosis of pediatric relapsed ALL patients has improved, but the 5-year OS of patients with first recurrence is still less than 50%, and the prognosis of children with intermediate and high risk is even worse, so there is an urgent need to explore new and effective treatment methods. A number of in vitro studies have shown that arsenic trioxide (ATO), which is safe and effective in the treatment of APL, can selectively inhibit the growth and induce apoptosis in a variety of leukemia cell lines, suggesting that ATO as a synergist combined with other common chemotherapy drugs may provide a new target for the treatment of relapsed ALL. Realgar Indigo naturalis formula is a compound traditional Chinese medicine preparation developed in China. The main component of realgar is arsenic tetrasulfide (As4S4), which can produce similar pharmacological effects to ATO. The UK ALL R3 protocol is an advanced and mature clinical trial. The results showed that the MRD negative rate after induction chemotherapy and the 2-year DFS of traditional chemotherapy ±HSCT in children with intermediate and high risk did not reach 50%. Based on the R3 protocol, this study plans to perform a double-blind randomized controlled trial, and to randomly combine compound Huangdai tablets with compound Huangdai tablets in the treatment of intermediate and high risk ALL children, in order to improve the MRD negative rate after induction therapy in this group of children, which may provide a new method for the clinical treatment of relapsed ALL.

Inclusion Criteria:

• B or T cell type;
• the first recurrence;
• the risk stratification was medium or high risk.

Exclusion Criteria:

• mature B cell leukemia;
• acute mixed phenotype leukemia;
• patients with positive BCR/ABL fusion gene;
• the second tumor
• definite CML blast crisis;
• ALL with Down's syndrome.