Case series : Changing Practice in Childhood Acute Promyelocytic Leukaemia: A Case Series on Reduced-Intensity ATRA and Arsenic Trioxide Regimens in Bangladesh with excellent outcome.

Abstract

Background: Acute promyelocytic leukaemia (APL) is one of the most curable forms of acute myeloid leukaemia following treatment with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Risk-adapted ATRA-ATO regimens with reduced chemotherapy exposure are increasingly used to minimize toxicity and treatment burden. However, experience with reduced-dose ATRA in children remains limited in Bangladesh.
Objective: To describe the treatment, toxicity, and molecular outcomes of children with APL treated with risk-adapted ATRA-ATO-based regimens.
Case Presentation: Five children with newly diagnosed APL, aged 3.8–12 years, were treated at Khwaja Yunus Ali Medical College & Hospital, Bangladesh, during 2025. Diagnosis was confirmed by bone marrow morphology, immunophenotyping, and PML-RARA RT-PCR. Patients were risk-stratified according to presenting white blood cell count. One standard-risk patient received the Lo-Coco regimen with ATRA 45 mg/m²/day and ATO 0.15 mg/kg/day. Four patients received the COG AAML1331-based regimen with reduced-dose ATRA 25 mg/m²/day and ATO 0.15 mg/kg/day; two high-risk patients also received limited-dose idarubicin.
Results: All five patients achieved morphological remission after induction and complete molecular remission after the second consolidation, confirmed by negative PML-RARA RT-PCR. Toxicities were manageable. Differentiation syndrome and leucocytosis responded to dexamethasone and hydroxyurea, respectively. Severe pseudotumor cerebri occurred in the patient receiving ATRA 45 mg/m²/day but was not observed among those receiving 25 mg/m²/day.
Conclusion: Risk-adapted ATRA-ATO therapy, including reduced-dose ATRA, appears feasible and effective for childhood APL in a resource-constrained setting. These encouraging findings warrant larger studies with longer follow-up.

KYAMC Journal Vol. 16, No. 04, January 2026: 232-235.