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Treatments for acute promyelocytic leukemia
Acute promyelocytic leukemia (APL) is a subtype of acute myelogenous leukemia (AML) that has its own treatment options.
The goal of induction treatment for APL is to treat all the leukemia cells in the blood and bone marrow and bring about a remission.
Tretinoin (all-trans retinoic acid, ATRA, Vesanoid) is used to treat APL. It is a drug derived from vitamin A. It must be followed by or given with other chemotherapy drugs to bring about a long-lasting remission. About 80%–90% of people with APL reach a long-lasting remission.
An anthracycline drug, such as one of the following, is given in combination with tretinoin:
- daunorubicin (Cerubidine, daunomycin)
- idarubicin (Idamycin)
Tretinoin may be given in combination with arsenic trioxide, rather than with an anthracycline drug, when the white blood cell count at diagnosis is 10,000 or less.
Consolidation treatment is also called post-remission therapy. The goal of consolidation treatment for APL is to treat any leukemia cells that are still in the blood or bone marrow once remission is reached. It is done to maintain complete remission and prevent relapse.
During consolidation treatment for APL, tretinoin is continued along with idarubicin or daunorubicin. Other drugs that may be added include:
- cytarabine (Cytosar)
- mercaptopurine (Purinethol, 6-MP)
- arsenic trioxide
The goal of maintenance treatment for APL is to prevent leukemia cells from coming back (called relapse).
Maintenance treatment includes continuing tretinoin for 1–2 years. Tretinoin may be used alone or in combination with:
Treatments for relapsed or refractory APL
Relapsed, or recurrent, APL means the leukemia has come back after treatment and reaching remission. Refractory APL means the leukemia did not respond to treatment. Complete remission has not been reached because the chemotherapy did not kill enough leukemia cells.
The most common treatment for relapsed or refractory APL includes:
- tretinoin and a chemotherapy drug such as cytarabine and daunorubicin
- arsenic trioxide
- allogeneic or autologous stem cell transplant (offered for relapsed APL if a second remission is reached)
Supportive therapy is important during every phase of APL treatment. It is used to treat the complications that usually happen with treatments for APL and the disease itself.
Supportive therapies given during treatment for relapsed or refractory APL may include:
- antibiotics and antifungals to treat infections
- growth factorsgrowth factorsA substance that regulates the growth, division and survival of cells. to help the bone marrow recover from chemotherapy (chemotherapy can affect the bone marrow so it doesn’t make enough healthy blood cells, which can increase the risk for infection)
- transfusions of red blood cells, platelets, fresh frozen plasma and cryoprecipitate (a product that replaces clotting factors) as needed
Treatments for differentiation syndrome
Differentiation syndrome used to be called retinoic acid syndrome. It is a complication caused by tretinoin, and it may also happen with arsenic trioxide. It is most often seen during the first cycle of treatment with these drugs.
The symptoms of differentiation syndrome include:
- weight gain
- swelling caused by a buildup of fluid in the body (called edema)
- buildup of fluid around the lungs (called pleural effusion)
- buildup of fluid around the heart (called pericardial effusion)
- shortness of breath
- difficulty breathing
- low blood pressure
If the symptoms of differentiation syndrome are mild, you can usually keep taking tretinoin or arsenic trioxide. Doctors will also prescribe a steroid, such as dexamethasone (Decadron, Dexasone).
If differentiation syndrome is severe, doctors will stop giving tretinoin or arsenic trioxide and give steroids until the symptoms completely go away. Once the symptoms go away, you can start taking the drug again, usually along with dexamethasone.
You may be asked if you want to join a clinical trial for APL. Find out more about clinical trials.