arsenic trioxide + cytarabine

**Arsenic trioxide + cytarabine** is a combination drug regimen investigated mainly for the treatment of hematological malignancies, particularly in elderly or high-risk patients with acute myeloid leukemia (AML) or advanced myelodysplastic syndrome (MDS). Arsenic trioxide induces apoptosis and differentiation in malignant hematopoietic cells, while cytarabine is an antimetabolite that inhibits DNA synthesis by incorporation into DNA and RNA, leading to cell cycle arrest and apoptosis. The combination has demonstrated clinical activity and tolerable toxicity profiles in phase 1/2 studies, showing improved response rates over either drug alone in some patient populations. Development has particularly focused on cases with poor prognosis, including secondary AML, AML with poor cytogenetics, and high-risk MDS[1][2][3][4][5].