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Acute Promyelocytic Leukemia (APL)

Also called: APL, acute myeloid leukemia (AML) M3; leukemia, acute promyelocytic

What is acute promyelocytic leukemia?

In acute promyelocytic leukemia (APL), the bone marrow produces too many cells called promyelocytes. When too many promyelocytes gather in the marrow, they crowd out healthy blood cells. If there are not enough healthy blood cells to do their jobs, patients are at high risk for infection or bleeding.

APL is a subtype of the cancer acute myeloid leukemia (AML). About 4 to 8 percent of all childhood AML is acute promyelocytic leukemia.

How common is acute promyelocytic leukemia?

Around 1 percent of all childhood leukemias are APL, which is most often diagnosed in children of Hispanic or Mediterranean descent. It is very rare in children younger than 3. The average age of diagnosis is 8 to 10 years. An APL diagnosis should be considered a medical emergency. If you have been told that your child may have APL, the child needs medical attention right away.

What are the symptoms of acute promyelocytic leukemia?

If your child has APL, the following symptoms may be present:

  • Bleeding that is hard to stop, even from a small cut
  • Blood in the urine
  • Heavy nosebleeds
  • Bleeding gums and easy bruising
  • Fever and infections
  • Low red blood cell count
  • Paleness
  • Tiring easily
  • Poor appetite
  • Unexplained weight loss

How is acute promyelocytic leukemia treated?

Treatment of APL differs from treatments for other forms of leukemia. Many children with APL require admission to the intensive care unit because of problems that occur when treatment begins.

In general, treatment of APL has three phases:

  • Induction. This phase often includes giving all-trans retinoic acid (ATRA), which is similar to vitamin A. It is combined with standard chemotherapy. Future studies plan to use arsenic trioxide during induction for a selected group of patients.
  • Consolidation/intensification. In this phase, ATRA, a drug known as arsenic trioxide and chemotherapy are given together. The combination is used to get rid of any cells that may have been inactive during the first phase but could start to grow and cause APL to return (relapse).
  • Maintenance. ATRA and chemotherapy are given for about a year to avoid a relapse of APL.

Because this three-phase treatment is usually successful, stem cell transplantation (which helps grow healthy blood-forming cells) is not usually done.

If APL returns, most children can be put into a second remission using arsenic trioxide, alone or combined with chemotherapy and stem cell transplantation.

What is the survival rate for acute promyelocytic leukemia?

At least 85–90 percent of children treated for APL are considered cured.

Why choose St. Jude for your child’s acute promyelocytic leukemia treatment?

  • St. Jude is the only National Cancer Institute-designated Comprehensive Cancer Center devoted solely to children.
  • St. Jude has created more clinical trials for cancer than any other children’s hospital in the United States.
  • The nurse-to-patient ratio at St. Jude is unmatched—averaging 1:3 in hematology and oncology, and 1:1 in the Intensive Care Unit.
  • The hospital’s leukemia studies have pioneered the way the world treats childhood leukemia.
  • The mortality rate during treatment induction of acute myeloid leukemia and acute promyelocytic leukemia is among the lowest in the nation.

Associated Clinical Trials

ALTE1631: Web-based Exercise Study for Children and Adolescents with Cancer

Web-based Physical Activity Intervention among Children and Adolescents with Cancer

Diseases Treated:

leukemia, solid tumor, brain tumor, lymphoma, carcinoma


This is a non-therapeutic clinical trial open to patients receiving treatment at a Children’s Oncology Group (COG)-affiliated institution.

  • At least 8 years old and younger than 16 years old
  • Diagnosed with childhood cancer, in remission
  • Completed therapy within the past 12 months
  • Performance status corresponding to ECOG scores of 0, 1, 2
  • Fewer than 420 minutes of moderate to vigorous physical activity (MVPA) over the last week
  • Able to write and read English, Spanish or French (patient and at least one parent/guardian)
  • Not pregnant
View Trial

AML23: Clinical Trial Studying the Safety of Using Venetoclax and Chemotherapy to Treat Newly Diagnosed Childhood AML

A Collaborative Phase 2 Study of Venetoclax in Combination with Conventional Chemotherapy in Pediatric Patients with Acute Myeloid Leukemia

Diseases Treated:

Acute Myeloid Leukemia (AML)


  • Diagnosed with AML
  • Older than 28 days and younger than 22 years
  • No prior AML treatment
View Trial

APAL2020D: Venetoclax in Children with Relapsed Acute Myeloid Leukemia (AML)

A Randomized Phase 3 Trial of Fludarabine/Cytarabine/Gemtuzumab Ozogamicin With or Without Venetoclax in Children With Relapsed AML

Diseases Treated:

Acute Myeloid Leukemia (AML)


  • Diagnosis of relapsed acute myeloid leukemia (AML)
  • Ages 29 days old to 21 years old
  • Have had AML come back for the first or second time
  • May have heart problems that prevent them from taking anthracyclines
View Trial

CATCHAML: CAR T-Cell Therapy for Acute Myelogenous Leukemia (AML)

CATCHAML: CD123-Directed Autologous T-Cell Therapy for Acute Myelogenous Leukemia

Diseases Treated:

Acute Myelogenous Leukemia


  • 21 years old or younger
  • Relapsed/refractory CD123+ AML, B-ALL, T-ALL or blastic plasmacytoid dendritic cell neoplasm
  • Has a suitable bone marrow transplant donor for allogeneic bone marrow transplant
View Trial

CN160: Ruxolitinib Therapy in Children after Bone Marrow Transplant

A Phase II Pediatric Study of a Graft-vs.-host disease (GVHD) prophylaxis regimen with no calcineurin inhibitors after day +60 post first allogeneic hematopoietic cell transplant for hematological malignancies

Diseases Treated:


  • Ages 12–21 years
  • Lymphoid or myeloid-based cancer that requires a bone marrow transplant


View Trial

CPXSMN: CPX-351 in Pediatric Patients with Secondary Myeloid Neoplasms

A Prospective, Multicenter, Single-Arm Pilot Study of CPX-351 (VYXEOS) in Individuals < 22 Years with Secondary Myeloid Neoplasms

Diseases Treated:


  • 1–22 years old
  • Treatment-related or secondary MDS/AML 
View Trial

DIRECT70: CAR T–Cell Therapy for Children with Blood Malignancies

DIRECT70: CAR T–Cell Therapy Directed to CD70 for Pediatric Patients with Hematological Malignancies (DIRECT70)

Diseases Treated:



  • Up to 21 years old
  • CD70+ acute myeloid leukemia, acute lymphoblastic leukemia (B-ALL, T-ALL), lymphoma, or myelodysplastic syndrome
  • If prior allogeneic hematopoietic cell transplant, no graft vs. host disease
  • Has an identified hematopoietic cell transplantation donor
  • Has adequate organ function
View Trial

DSCOG: Learning, Behavior and Social Skills in Survivors of Childhood Leukemia with Down syndrome

Neurocognitive and Psychosocial Outcomes in Survivors of Childhood Leukemia with Down syndrome

Diseases Treated:



This is a non-therapeutic clinical trial that is open only to patients who were treated at St. Jude Children’s Research Hospital since 1980 and are currently followed at the hospital.

  • St. Jude Children’s Research Hospital patient with acute leukemia (i.e., ALL or AML)
  • Trisomy 21 Down syndrome diagnosis
  • Completed all cancer therapy at St. Jude since 1980 and at least six months prior to study visit
  • English as the primary language
View Trial

HAP2HCT: Partially Matched Family Donor Bone Marrow Transplant in Children and Young Adults with High Risk Cancer

TCRαβ-depleted Progenitor Cell Graft with Additional Memory T-Cell DLI, plus Selected Use of Blinatumomab, in Naïve T-Cell depleted Haploidentical Donor Hematopoietic Cell Transplantation for Hematologic Malignancies

Diseases Treated:


For transplant recipient:

  • 21 years or younger
  • Does not have a suitable sibling donor or volunteer unrelated donor
  • Has a suitable single haplotype matched family member donor
  • Diagnosed with high risk hematologic malignancy
  • No prior allogeneic hematopoietic cell transplant
View Trial

HAPNK1: Blood and Marrow Transplant (BMT) for Children with Leukemia/Lymphoma

Haploidentical Donor Hematopoietic Progenitor Cell and Natural Killer Cell Transplantation with a TLI-Based Conditioning Regimen in Patients with Hematologic Malignancies

Diseases Treated:

Leukemia and lymphoma


  • 21 years and younger
  • Does not have a suitable HLA-matched sibling donor or volunteer HLA-matched unrelated donor or is not a candidate for conventional matched donor transplant due to refractory disease
  • Has a suitable single haplotype-matched family member donor
  • High-risk hematologic malignancy, including certain diagnoses of:
    • Acute lymphoblastic leukemia (ALL)
    • Acute myeloid leukemia (AML)
    • Chronic myelogenous leukemia (CML)
    • Myelodysplastic syndrome (MDS)
    • Hodgkin lymphoma
    • Non-Hodgkin lymphoma
View Trial

NCBP01: Safety Study of Unlicensed, Investigational Cord Blood Units Manufactured by the NCBP for Unrelated Transplantation

A Multicenter Safety Study of Unlicensed, Investigational Cryopreserved Cord Blood Units (CBUs) manufactured by the National Cord Blood Program (NCBP) and provided for Unrelated Hematopoietic Stem Cell Transplantation of Pediatric and Adult Patients

Diseases Treated:

Leukemia and other blood diseases


This is a non-therapeutic clinical trial that is only open to St. Jude patients.

  • Participant is receiving an allogeneic hematopoietic stem cell (HSC) transplant at St. Jude Children's Research Hospital using an unlicensed cord blood unit (CBU).
  • Participant may be of any age and either gender.
  • Participant has a medical disorder affecting the hematopoietic system that is inherited, acquired, or a result from myeloablative treatment.
  • Participant is receiving HPC-CORD BLOOD product manufactured by NCBP (at least one, if the graft contains more than one units).
View Trial

PAINBDY1: Treating Pain in Children with Cancer: Pain Buddy

Treating Pain in Children with Cancer: A 21st Century Innovative Approach (Pain Buddy)

Diseases Treated:

Endocrine Tumors
Ewing Sarcoma


This is a research study open only to St. Jude patients and their caregivers.

  • 8 to 18 years old
  • Within 16 weeks of initial cancer diagnosis
  • Receiving outpatient chemotherapy treatment for cancer
  • Can speak, read and write English. Parents who can speak, read, and write in English and Spanish
  • Have Internet access
View Trial

RAVAML: Revumenib, Azacitidine, and Venetoclax in Acute Myeloid Leukemia

A Phase 1 Study of Revumenib, Azacitidine, and Venetoclax in Pediatric and Young Adult Patients with Refractory or Relapsed Acute Myeloid Leukemia

Diseases Treated:

Acute Myeloid Leukemia (AML)
Acute Leukemia of Ambiguous Lineage (ALAL)


  • 1–30 years old
  • Acute myeloid leukemia or acute leukemia of ambiguous lineage
  • Specific genetic changes
  • Adequate organ function
View Trial

REF2HCT: Haploidentical Bone Marrow Transplant for Leukemia and Lymphoma

Provision of TCRγδ T Cells and Memory T Cells plus Selected Use of Blinatumomab in Naïve T-cell Depleted Haploidentical Donor Hematopoietic Cell Transplantation for Hematologic Malignancies Relapsed or Refractory despite Prior Transplantation

Diseases Treated:


  • 21 years old and younger
  • Diagnosed with one of the following that has come back or did not improve after bone marrow transplant
    • Acute lymphoblastic leukemia (ALL)
    • Acute myeloid leukemia
    • Myeloid sarcoma
    • Chronic myeloid leukemia (CML)
    • Juvenile myelomonocytic leukemia (JMML)
    • Myelodysplastic syndrome (MDS)
    • Non-Hodgkin lymphoma (NHL)
  • Has a family member who is a suitable stem cell donor
View Trial

SELCLAX: A Study of Venetoclax and Selinexor with Chemotherapy in Children with AML

A Phase 1 Study of Venetoclax and Selinexor in Combination with Chemotherapy in Pediatric Patients with Refractory or Relapsed Acute Myeloid Leukemia

Diseases Treated:

Acute myeloid leukemia


  • Diagnosis of one of the following:
    • Relapsed or refractory acute myeloid leukemia (AML)
    • Relapsed or refractory acute leukemia of ambiguous lineage (ALAL)
  • 30 years old or younger (24 years or younger at St. Jude)
  • Ineligible for other curative therapy
View Trial

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