From the Guidelines
APL, or Acute Promyelocytic Leukemia, is a unique subtype of acute myeloid leukemia characterized by a specific genetic abnormality, and it is highly curable with a combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). The disease is notable for its high risk of severe bleeding complications and its remarkable response to targeted therapies, as reported in the study by 1. Key characteristics of APL include:
- A specific genetic abnormality - the fusion of the PML gene on chromosome 15 with the RARA gene on chromosome 17
- High risk of severe bleeding complications
- Remarkable response to targeted therapies, such as ATRA and ATO
- Highly curable with a combination of ATRA and ATO, which work by forcing the abnormal promyelocytes to mature properly
- Early diagnosis and prompt treatment are crucial, as the bleeding risk is highest before treatment begins, as emphasized in the study by 1. APL typically presents with symptoms like:
- Fatigue
- Easy bruising
- Bleeding
- Increased risk of infections The disease's excellent response to targeted therapy has transformed it from one of the most fatal to one of the most curable forms of acute leukemia, with survival rates exceeding 70% in multicenter clinical trials, as reported in the study by 1.
From the FDA Drug Label
Patients with acute promyelocytic leukemia (APL) treated with arsenic trioxide injection have experienced symptoms of differentiation syndrome, which can be fatal if not treated Arsenic trioxide injection is indicated for induction of remission and consolidation in patients with APL who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression. Tretinoin induces cytodifferentiation and decreased proliferation of APL cells in culture and in vivo
APL Definition:
- APL stands for Acute Promyelocytic Leukemia
- It is a type of blood cancer characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression 2
- APL is treated with medications such as arsenic trioxide injection and all-trans retinoic acid (tretinoin) 2 3
From the Research
Definition of APL
- Acute promyelocytic leukemia (APL) is a rare type of acute myeloid leukemia (AML) characterized by the t(15;17) translocation and accounting for 8-15% of cases 4.
- APL is associated with severe coagulopathy leading to rapid morbidity and mortality if left untreated 5.
- The definitive diagnosis of APL is made by identifying a balanced reciprocal translocation between chromosomes 15 and 17, resulting in a fusion transcript of promyelocytic leukemia (PML) and retinoic acid receptor alpha (RARA) genes 5.
Treatment and Prognosis
- APL is cured in over 90% of cases, making it the most curable subtype of acute leukemia today 5.
- Patients with low-risk APL are successfully treated using a chemotherapy-free combination of all-trans retinoic acid and arsenic trioxide (ATO) 6, 7, 8.
- The introduction of target therapies, such as all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), radically changed the management of APL, making it the most curable AML subtype 4.
- Oral arsenic plus ATRA without chemotherapy was active as a first-line consolidation therapy for high-risk APL 6.
Characteristics and Subtypes
- APL-like AML is a rare group of AML that presents with APL-like morphology and/or immunophenotype but lacks the t(15;17) translocation 4.
- This rare APL-like AML group includes over 40 entities, presenting great heterogeneity in terms of genetic lesions, clinical presentation, sensitivity to targeted agents and chemotherapy, and prognosis 4.