First-line treatment of AML consists primarily of chemotherapy, and is divided into two phases: induction and postremission (or consolidation) therapy. The goal of induction therapy is to achieve a complete remission by reducing the number of leukemic cells to an undetectable level; the goal of consolidation therapy is to eliminate any residual undetectable disease and achieve a cure. Hematopoietic stem cell transplantation is usually considered if induction chemotherapy fails or after a person relapses, although transplantation is also sometimes used as front-line therapy for people with high-risk disease. Efforts to use tyrosine kinase inhibitors in AML continue.

Many different anti-cancer drugs are effective for the treatment of AML. Treatments vary somewhat according to the age of the patient and according to the specific subtype of AML. Overall, the strategy is to control bone marrow and systemic (whole-body) disease, while offering specific treatment for the central nervous system (CNS), if involved.

In general, most oncologists rely on combinations of drugs for the initial, "induction phase" of chemotherapy. Such combination chemotherapy usually offers the benefits of early remission and a lower risk of disease resistance. "Consolidation" and "maintenance" treatments are intended to prevent disease recurrence. Consolidation treatment often entails a repetition of induction chemotherapy or the intensification chemotherapy with additional drugs. By contrast, maintenance treatment involves drug doses that are lower than those administered during the induction phase.

Combination chemotherapy regimens are effective in both newly diagnosed and relapsed CLL. Combinations of fludarabine with alkylating agents (cyclophosphamide) produce higher response rates and a longer progression-free survival than single agents:

- FC (fludarabine with cyclophosphamide)

- FR (fludarabine with rituximab)

- FCR (fludarabine, cyclophosphamide, and rituximab)

- CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone)

Although the purine analogue fludarabine was shown to give superior response rates to chlorambucil as primary therapy, no evidence shows early use of fludarabine improves overall survival, and some clinicians prefer to reserve fludarabine for relapsed disease.

Chemoimmunotherapy with FCR has shown to improve response rates, progression-free survival, and overall survival in a large randomized trial in CLL patients selected for good physical fitness. This has been the first clinical trial demonstrating that the choice of a first-line therapy can improve the overall survival of patients with CLL.

Alkylating agents approved for CLL include bendamustine and cyclophosphamide.

To overcome imatinib resistance and to increase responsiveness to TK inhibitors, four novel agents were later developed. The first, dasatinib, blocks several further oncogenic proteins, in addition to more potent inhibition of the BCR-ABL protein, and was initially approved in 2007 by the US FDA to treat CML in patients who were either resistant to or intolerant of imatinib. A second new TK inhibitor, nilotinib, was also approved by the FDA for the same indication. In 2010, nilotinib and dasatinib were also approved for first-line therapy, making three drugs in this class available for treatment of newly diagnosed CML. In 2012, Radotinib joined the class of novel agents in the inhibition of the BCR-ABL protein and was approved in South Korea for patients resistant to or intolerant of imatinib. Bosutinib received US FDA and EU European Medicines Agency approval on September 4, 2012 and 27 March 2013 respectively for the treatment of adult patients with Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) with resistance, or intolerance to prior therapy.

For most people with CLL, it is incurable by present treatments, so treatment is directed towards suppressing the disease for many years, rather than totally and permanently eliminating it. The primary chemotherapeutic plan is combination chemotherapy with chlorambucil or cyclophosphamide, plus a corticosteroid such as prednisone or prednisolone. The use of a corticosteroid has the additional benefit of suppressing some related autoimmune diseases, such as immunohemolytic anemia or immune-mediated thrombocytopenia. In resistant cases, single-agent treatments with nucleoside drugs such as fludarabine, pentostatin, or cladribine may be successful. Younger and healthier patients may choose allogeneic or autologous bone marrow transplantation in the hope of a permanent cure.

Targeted therapy attacks cancer cells at a specific target, with the aim of not harming normal cells.

- Alemtuzumab is a mAb directed against CD52 used in CLL.

- Rituximab, ofatumumab, and obinutuzumab are antibodies against CD20 used to treat CLL.

- Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, is used to treat CLL.

- Idelalisib is a PI3K inhibitor. and is taken orally.

- Venetoclax is a Bcl-2 inhibitor used to treat people with CLL who have 17p deletion (deletion located on the chromosome 17 short arm) and who have been treated with at least one prior therapy.

In the past, antimetabolites (e.g., cytarabine, hydroxyurea), alkylating agents, interferon alfa 2b, and steroids were used as treatments of CML in the chronic phase, but since the 2000s have been replaced by Bcr-Abl tyrosine-kinase inhibitors drugs that specifically target BCR-ABL, the constitutively activated tyrosine kinase fusion protein caused by the Philadelphia chromosome translocation. Despite the move to replacing cytotoxic antineoplastics (standard anticancer drugs) with tyrosine kinase inhibitors sometimes hydroxyurea is still used to counteract the high leukocyte counts encountered during treatment with tyrosine kinase inhibitors like imatinib; in these situations it may be the preferred myelosuppressive agent due to its relative lack of leukemogenic effects and hence the relative lack of potential for secondary hematologic malignancies to result from treatment. IRIS, an international study that compared interferon/cytarabine combination and the first of these new drugs imatinib, with long-term follow up, demonstrated the clear superiority of tyrosine-kinase-targeted inhibition over existing treatments.

Radiation therapy (or radiotherapy) is used on painful bony areas, in high disease burdens, or as part of the preparations for a bone marrow transplant (total body irradiation). In the past, physicians commonly utilized radiation in the form of whole-brain radiation for central nervous system prophylaxis, to prevent occurrence and/or recurrence of leukemia in the brain. Recent studies showed that CNS chemotherapy provided results as favorable but with less developmental side-effects. As a result, the use of whole-brain radiation has been more limited. Most specialists in adult leukemia have abandoned the use of radiation therapy for CNS prophylaxis, instead using intrathecal chemotherapy.

Chemotherapy is the initial treatment of choice, and most ALL patients receive a combination of medications. There are no surgical options because of the body-wide distribution of the malignant cells. In general, cytotoxic chemotherapy for ALL combines multiple antileukemic drugs tailored to each patient. Chemotherapy for ALL consists of three phases: remission induction, intensification, and maintenance therapy.

Due to presence of CNS involvement in 10–40% of adult patients at diagnosis, most providers start Central nervous system (CNS) prophylaxis and treatment during the induction phase, and continue it during the consolidation/intensification period.

Adult chemotherapy regimens mimic those of childhood ALL; however, are linked with a higher risk of disease relapse with chemotherapy alone. It should be known that 2 subtypes of ALL (B-cell ALL and T-cell ALL) require special considerations when it comes to selecting an appropriate treatment regimen in adult patients. B-cell ALL is often associated with cytogenetic abnormalities (specifically, t(8;14), t (2;8) and t(8;22)), which require aggressive therapy consisting of brief, high-intensity regimens. T-cell ALL responds to cyclophosphamide-containing agents the most.

As the chemotherapy regimens can be intensive and protracted, many patients have an intravenous catheter inserted into a large vein (termed a central venous catheter or a Hickman line), or a Portacath, usually placed near the collar bone, for lower infection risks and the long-term viability of the device.

Males usually endure a longer course of treatment than females as the testicles can act as a reservoir for the cancer.

All FAB subtypes except M3 are usually given induction chemotherapy with cytarabine (ara-C) and an anthracycline (most often daunorubicin). This induction chemotherapy regimen is known as "7+3" (or "3+7"), because the cytarabine is given as a continuous IV infusion for seven consecutive days while the anthracycline is given for three consecutive days as an IV push. Up to 70% of people with AML will achieve a remission with this protocol. Other alternative induction regimens, including high-dose cytarabine alone, FLAG-like regimens or investigational agents, may also be used. Because of the toxic effects of therapy, including myelosuppression and an increased risk of infection, induction chemotherapy may not be offered to the very elderly, and the options may include less intense chemotherapy or palliative care.

The M3 subtype of AML, also known as acute promyelocytic leukemia (APL), is almost universally treated with the drug all-"trans"-retinoic acid (ATRA) in addition to induction chemotherapy, usually an anthracycline. Care must be taken to prevent disseminated intravascular coagulation (DIC), complicating the treatment of APL when the promyelocytes release the contents of their granules into the peripheral circulation. APL is eminently curable, with well-documented treatment protocols.

The goal of the induction phase is to reach a complete remission. Complete remission does not mean the disease has been cured; rather, it signifies no disease can be detected with available diagnostic methods. Complete remission is obtained in about 50%–75% of newly diagnosed adults, although this may vary based on the prognostic factors described above. The length of remission depends on the prognostic features of the original leukemia. In general, all remissions will fail without additional consolidation therapy.

After stable remission is induced, the standard of care is to undergo 2 years of maintenance chemotherapy with methotrexate, mercaptopurine and ATRA. A significant portion of patients will relapse without consolidation therapy. In the 2000 European APL study, the 2-year relapse rate for those that did not receive consolidation chemotherapy (ATRA not included) therapy was 27% compared to 11% in those that did receive consolidation therapy (p<0.01). Likewise in the 2000 US APL study, the survival rates in those receiving ATRA maintenance was 61% compared to just 36% without ATRA maintenance.

Arsenic trioxide (AsO) is currently being evaluated for treatment of relapsed / refractory disease. Remission with arsenic trioxide has been reported.

Studies have shown arsenic reorganizes nuclear bodies and degrades the mutant PML-RAR fusion protein. Arsenic also increases caspase activity which then induces apoptosis. It does reduce the relapse rate for high risk patients. In Japan a synthetic retinoid, tamibarotene, is licensed for use as a treatment for ATRA-resistant APL.

The role of chemotherapy or other pharmacologic treatments against JMML before bone marrow transplant has not been studied completely and its importance is still unknown. Chemotherapy by itself has proven unable to bring about long-term survival in JMML.

- Low-dose conventional chemotherapy: Studies have shown no influence from low-dose conventional chemotherapy on JMML patients’ length of survival. Some combinations of 6-mercaptopurine with other chemotherapy drugs have produced results such as decrease in organ size and increase or normalization of platelet and leukocyte count.

- Intensive chemotherapy: Complete remission with ongoing durability from JMML has not been possible through use of intensive chemotherapy, but it is still used at times because it has improved the condition of a small but significant number of JMML patients who do not display an aggressive disease. The COG JMML study administers 2 cycles of fludarabine and cytarabine for 5 consecutive days along with 13-cis retinoic acid during and afterwards. The EWOG-MDS JMML study, however, does not recommend intensive chemotherapy before bone marrow transplant.

- 13-cis retinoic acid (Isotretinoin): In the lab, 13-cis-retinoic acid has inhibited the growth of JMML cells. The COG JMML study therefore includes 13-cis-retinoic acid in its treatment protocol, though its therapeutic value for JMML remains controversial.

The theory behind splenectomy in JMML is that the spleen may trap leukemic cells, leading to the spleen's enlargement, by harboring dormant JMML cells that are not eradicated by radiation therapy or chemotherapy for the active leukemia cells, thus leading to later relapse if the spleen is not removed. However, the impact of splenectomy on post-transplant relapse, though, is unknown. The COG JMML study includes splenectomy as a standard component of treatment for all clinically stable patients. The EWOG-MDS JMML study allows each child’s physician to determine whether or not a splenectomy should be done, and large spleens are commonly removed prior to bone marrow transplant. When a splenectomy is scheduled, JMML patients are advised to receive vaccines against "Streptococcus pneumoniae" and "Haemophilus influenza" at least 2 weeks prior to the procedure. Following splenectomy, penicillin may be administered daily in order to protect the patient against bacterial infections that the spleen would otherwise have protected against; this daily preventative regimen will often continue indefinitely.

Natural killer (NK) cell therapy is used in pediatrics for children with relapsed lymphoid leukemia. These patients normally have a resistance to chemotherapy, therefore, in order to continue on, must receive some kind of therapy. In some cases, NK cell therapy is a choice.

NK cells are known for their ability to eradicate tumor cells without any prior sensitization to them. One problem when using NK cells in order to fight off lymphoid leukemia is the fact that it is hard to amount enough of them to be effective. One can receive donations of NK cells from parents or relatives through bone marrow transplants. There are also the issues of cost, purity and safety. Unfortunately, there is always the possibility of Graft vs host disease while transplanting bone marrow.

NK cell therapy is a possible treatment for many different cancers such as Malignant glioma.

AML-M5 is treated with intensive chemotherapy (such as anthracyclines) or with bone marrow transplantation.

If a patient has the symptoms like leukemia, such as persistent fever or difficulty of hemostais, he has to see the doctors.

BAL is very hard to treat. Most of patients receive treatment based on the morphology of blasts and get AML or ALL induction chemotherapy. The induction drug for AML such as cytarabine and anthracycline, drug for ALL such as prednisolone, dexamethasone, vincristine, asparaginase or daunorubicin is common for BAL remission induction therapy. Recently, researches showed that using both myeloid and lymphoid induction therapy may be better for prognosis.

Chemotherapy is strong side effects such as typhlitis, gastrointestinal distress, anemia, fatigue, hair loss, nausea and vomiting, etc. Thus, the different dose and times of chemotherapy for different individuals is important.

If the patients enter fully remission, the consolidation with stem cell transplantation is highly recommended.

As described above, chloromas should always be considered manifestations of systemic disease, rather than isolated local phenomena, and treated as such. In the patient with newly diagnosed leukemia and an associated chloroma, systemic chemotherapy against the leukemia is typically used as the first-line treatment, unless an indication for local treatment of the chloroma (e.g. compromise of the spinal cord) emerges. Chloromas are typically quite sensitive to standard antileukemic chemotherapy. Allogeneic hematopoietic stem cell transplantation should be considered in fit patients with suitable available donor, as long term remissions have been reported.

If the chloroma is persistent after completion of induction chemotherapy, local treatment, such as surgery or radiation therapy, may be considered, although neither has an effect on survival.

Patients presenting with a primary chloroma typically receive systemic chemotherapy, as development of acute leukemia is nearly universal in the short term after detection of the chloroma.

Patients treated for acute leukemia who relapse with an isolated chloroma are typically treated with systemic therapy for relapsed leukemia. However, as with any relapsed leukemia, outcomes are unfortunately poor.

Patients with "preleukemic" conditions, such as myelodysplastic syndromes or myeloproliferative syndromes, who develop a chloroma are often treated as if they have transformed to acute leukemia.

Several treatments are available, and successful control of the disease is common.

Not everyone needs treatment immediately. Treatment is usually given when the symptoms of the disease interfere with the patient's everyday life, or when white blood cell or platelet counts decline to dangerously low levels, such as an absolute neutrophil count below one thousand cells per microliter (1.0 K/uL). Not all patients need treatment immediately upon diagnosis.

Treatment delays are less important than in solid tumors. Unlike most cancers, treatment success does not depend on treating the disease at an early stage. Because delays do not affect treatment success, there are no standards for how quickly a patient should receive treatment. However, waiting too long can cause its own problems, such as an infection that might have been avoided by proper treatment to restore immune system function. Also, having a higher number of hairy cells at the time of treatment can make certain side effects somewhat worse, as some side effects are primarily caused by the body's natural response to the dying hairy cells. This can result in the hospitalization of a patient whose treatment would otherwise be carried out entirely at the hematologist's office.

Single-drug treatment is typical. Unlike most cancers, only one drug is normally given to a patient at a time. While monotherapy is normal, combination therapy—typically using one first-line therapy and one second-line therapy—is being studied in current clinical trials and is used more frequently for refractory cases. Combining rituximab with cladribine or pentostatin may or may not produce any practical benefit to the patient. Combination therapy is almost never used with a new patient. Because the success rates with purine analog monotherapy are already so high, the additional benefit from immediate treatment with a second drug in a treatment-naïve patient is assumed to be very low. For example, one round of either cladribine or pentostatin gives the median first-time patient a decade-long remission; the addition of rituximab, which gives the median patient only three or four years, might provide no additional value for this easily treated patient. In a more difficult case, however, the benefit from the first drug may be substantially reduced and therefore a combination may provide some benefit.

The treatment a child will undergo is based on the child's age, overall health, medical history, their tolerance for certain medications, procedures, and therapies, along with the parents' opinion and preference.

- Chemotherapy is a treatment that uses drugs to interfere with the cancer cells ability to grow and reproduce. Chemotherapy can be used alone or in combination with other therapies. Chemotherapy can be given either as a pill to swallow orally, an injection into the fat or muscle, through an IV directly into the bloodstream, or directly into the spinal column.

- A stem cell transplant is a process by which healthy cells are infused into the body. A stem-cell transplant can help the human body make enough healthy white blood cells, red blood cells, or platelets, and reduce the risk of life-threatening infections, anemia, and bleeding. It is also known as a bone-marrow transplant or an umbilical-cord blood transplant, depending on the source of the stem cells. Stem cell transplants can use the cells from the same person, called an autologous stem cell transplant or they can use stem cells from other people, known as an allogenic stem cell transplant. In some cases, the parents of a child with childhood leukemia may conceive a saviour sibling by preimplantation genetic diagnosis to be an appropriate match for the HLA antigen.

Cladribine (2CDA) and pentostatin (DCF) are the two most common first-line therapies. They both belong to a class of medications called purine analogs, which have mild side effects compared to traditional chemotherapy regimens.

Cladribine can be administered by injection under the skin, by infusion over a couple of hours into a vein, or by a pump worn by the patient that provides a slow drip into a vein, 24 hours a day for 7 days. Most patients receive cladribine by IV infusion once a day for five to seven days, but more patients are being given the option of taking this drug once a week for six weeks. The different dosing schedules used with cladribine are approximately equally effective and equally safe.

Relatively few patients have significant side effects other than fatigue and a high fever caused by the cancer cells dying, although complications like infection and acute kidney failure have been seen.

Pentostatin is chemically similar to cladribine, and has a similar success rate and side effect profile, but it is always given over a much longer period of time, usually one dose by IV infusion every two weeks for three to six months.

During the weeks following treatment the patient's immune system is severely weakened, but their bone marrow will begin to produce normal blood cells again. Treatment often results in long-term remission. About 85% of patients achieve a complete response from treatment with either cladribine or pentostatin, and another 10% receive some benefit from these drugs, although there is no permanent cure for this disease. If the cancer cells return, the treatment may be repeated and should again result in remission, although the odds of success decline with repeated treatment. Remission lengths vary significantly, from one year to more than twenty years. The median patient can expect a treatment-free interval of about ten years.

It does not seem to matter which drug a patient receives. A patient who is not successfully treated with one of these two drugs has a reduced chance of being successfully treated with the other. However, there are other options.

While investigational drug therapies exist, no curative drug treatment exists for any of the MPDs. The goal of treatment for ET and PV is prevention of thrombohemorrhagic complications. The goal of treatment for MF is amelioration of anemia, splenomegaly, and other symptoms. Low-dose aspirin is effective in PV and ET. Tyrosine kinase inhibitors like imatinib have improved the prognosis of CML patients to near-normal life expectancy.

Recently, a "JAK2" inhibitor, namely ruxolitinib, has been approved for use in primary myelofibrosis. Trials of these inhibitors are in progress for the treatment of the other myeloproliferative neoplasms.

Treatment can occasionally consist of "watchful waiting" (e.g. in CLL) or symptomatic treatment (e.g. blood transfusions in MDS). The more aggressive forms of disease require treatment with chemotherapy, radiotherapy, immunotherapy and—in some cases—a bone marrow transplant. The use of rituximab has been established for the treatment of B-cell–derived hematologic malignancies, including follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL).

Treatment for erythroleukemia generally follows that for other types of AML, not otherwise specified. It consists of chemotherapy, frequently consisting of

cytarabine, daunorubicin, and idarubicin. It can also involve bone marrow transplantation.

If treatment has been successful ("complete" or "partial remission"), a person is generally followed up at regular intervals to detect recurrence and monitor for "secondary malignancy" (an uncommon side-effect of some chemotherapy and radiotherapy regimens—the appearance of another form of cancer). In the follow-up, which should be done at pre-determined regular intervals, general anamnesis is combined with complete blood count and determination of lactate dehydrogenase or thymidine kinase in serum.