From the Guidelines
Acute Promyelocytic Leukemia (APL) is managed with a combination of all-trans retinoic acid (ATRA) and anthracycline-based chemotherapy as the standard first-line treatment, which results in extremely high antileukemic efficacy, leading to complete remission (CR) in 90% to 95% of patients. The management of APL involves several key components, including:
- Induction therapy: The simultaneous administration of ATRA and anthracycline-based chemotherapy is currently considered the standard induction treatment in newly diagnosed patients with APL, as recommended by the European LeukemiaNet 1.
- Risk assessment: Patients are stratified into low-to-intermediate risk or high-risk groups based on their white blood cell count (WBC), with high-risk patients requiring additional chemotherapy such as idarubicin or daunorubicin during induction.
- Treatment duration: The treatment duration generally spans several months, with the goal of achieving complete remission and preventing relapse.
- Complication management: Differentiation syndrome and coagulopathy are potentially life-threatening complications that require immediate attention and management with dexamethasone and fibrinogen and platelet support, respectively.
- Relapse treatment: In cases of relapse, arsenic trioxide (ATO) is considered a highly effective treatment option, with a high rate of complete remission and survival, as reported in studies such as those published in the Journal of the National Comprehensive Cancer Network 1 and Blood 1. The unique sensitivity of APL to these targeted therapies is due to the PML-RARA fusion protein that blocks normal myeloid differentiation; ATRA and anthracycline-based chemotherapy bind to this protein, inducing differentiation of leukemic promyelocytes and eventual apoptosis, leading to improved outcomes and cure rates exceeding 90% in most patients when treatment is initiated promptly.
From the Research
Management of Acute Promyelocytic Leukemia (APL)
The management of APL involves various treatment approaches, including:
- Induction therapy with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) [(2,3,4,5)]
- Consolidation therapy with ATO and ATRA [(2,3,5)]
- Maintenance therapy with ATRA, 6-mercaptopurine, and methotrexate 3
- Use of gemtuzumab ozogamicin (GO) in high-risk patients or those with recurrent disease [(2,6)]
Treatment Outcomes
Studies have shown that the combination of ATRA and ATO is effective in achieving complete remission and improving overall survival in patients with APL [(2,3,5)]. The estimated 3-year survival rate is around 85% 2, and the 5-year event-free survival and overall survival rates are around 79% and 80%, respectively 3.
Treatment Considerations
The treatment approach may vary depending on the risk classification of the patient, with high-risk patients requiring more intensive therapy [(3,4)]. Additionally, the use of chemotherapy may be avoided in some cases, with ATRA and ATO being used as the primary treatment [(2,3,4,5)].
Recurrent Disease
In cases of recurrent APL, the combination of ATO, ATRA, and GO may be effective in achieving durable remissions 6. This approach may be considered as an alternative to allogeneic or autologous transplantation.