Remission Induction Therapy

During remission induction therapy, you are given large doses of chemotherapy over a period of 5 to 7 days. These chemotherapy drugs kill both leukemia cells and normal bone marrow cells. They are toxic to rapidly growing cells in the body (for example, normal bone marrow, skin, and the gastrointestinal tract. Their major side effects are related to this toxicity. Each drug also has specific side effects for other organs. 

Standard remission induction therapy currently consists of 3 days of a drug in the anthracycline class. These drugs prevents cancer cell division (replication). In addition, the drug Cytosar^® (cytarabine) is given for 7 days. Cytarabine interferes with the growth of cancer cells. 

Following remission induction, you usually need 2 to 3 weeks for bone marrow blood cell production to recover. During this time, blood and platelet transfusions are often necessary. To reduce the risk of infection, you may also be given antibiotics. 

Blood cell growth factors, such as Neupogen^®  (filgrastim), are used to stimulate bone marrow to produce normal white blood cells (neutrophils). After 2 to 3 weeks, your blood counts will begin to recover and often return to normal. A bone marrow examination is repeated to see if a remission has been achieved. 

If you are in remission, the consolidation therapy will begin. If you have not achieved a remission, another induction course of treatment may be given immediately. However, even if a remission is achieved with a second cycle of chemotherapy, remission duration is often shorter. 

If you have a compatible marrow donor, a stem cell transplant can be given immediately instead of a second course of induction therapy. Stem cells produce the different types of blood cells. They help to replace the faulty leukemia cells. Whether or not a stem cell transplant is given depends on your expected chance of cure with chemotherapy alone, based on the cytogenetics of your leukemia. 

There are two types of stem cell transplant. An autologous stem cell transplant involves the collection of a patient’s own stem cells before chemotherapy treatment. These stem cells are frozen and then put back into the patients after treatment to “rescue” the bone marrow. An allogeneic stem cell transplant uses stem cells collected from a related or unrelated donor. 

Treatment of patients with t(8;21) or inversion 16

Patients with these abnormalities have a very good prognosis with a cure rate of 60 percent. Once in complete remission, they must receive at least three to four courses of chemotherapy, including high doses of cytarabine to achieve these cure rates.

Special Treatments for Acute Promyelocytic Leukemia

Vesanoid^® (tretinoin), Trisenox^® (arsenic trioxide), and Mylotarg^® (gemtuzumab ozogamicin) may be included in the remission induction or salvage regimen for patients with acute promyelocytic leukemia (M3). Promyelocytic leukemia involves a shortage of mature blood cells and an excess of immature cells. Patients with acute promyelocytic leukemia usually receive tretinoin at some time during their treatment course. Clinical trials are in progress to find the best time to administer this drug. Acute promyelocytic leukemia may be cured at a rate of 70 percent to 80 percent with such treatments.

If you are in remission, there is a 90 percent chance that your disease will return within a few weeks or months without further therapy. To prevent this, consolidation therapy begins immediately after you recover from induction therapy. 

These treatments are given as close together as possible. The more intensive the chemotherapy and the closer together the courses of therapy are given, the less chance there is that the leukemia will return. It is very important to understand that lower doses of drugs do not work as well as higher doses of drugs. 

Research is in progress to refine existing treatments and develop new ones. For information on some of the techniques currently under investigation, see Strategies to Improve Treatment.