Leukemia

One leukemia Is a blood cancer And of the bone marrow which is characterized by excessive and uncontrolled production of abnormal white blood cells. These cancer cells gradually invade the bone marrow, disrupting the normal production of other blood cells (red blood cells, normal white blood cells, and platelets). In France, leukemias affect between 9,000 and 10,000 people each year. The median age at diagnosis varies according to the type of leukemia: chronic forms are more common in adults, especially the elderly, while acute forms can occur at any age, including children. Among those under 17 years of age, leukemias represent 26% of diagnosed cancer cases.

The treatment of acute leukemias is based on a multi-phase approach to eliminate leukemia cells and restore normal blood cell production.

Chemotherapy (basic treatment)

Chemotherapy is a treatment that uses powerful drugs to destroy cancer cells by stopping them from multiplying or spreading in the body. Chemotherapy medications can be given intravenously (into a vein), orally (as tablets or capsules), or by subcutaneous injection (under the skin).

Chemotherapy may be used alone or in combination with other treatments such as surgery or radiation therapy, depending on the type and stage of the cancer, as well as the patient’s overall health. While chemotherapy can be very effective in destroying cancer cells, it can also damage healthy cells, leading to side effects such as hair loss, fatigue, nausea and vomiting, and suppression of the immune system.

In the case of acute leukemias, the goal of chemotherapy is to destroy leukemia cells in the bone marrow and blood. It is used in all acute leukemias (ALL and AML). Among the most used chemotherapy drugs are:

• LAL : Combination of several drugs (vincristine, methotrexate, corticosteroids, anthracyclines).
• LAM : Protocols based on cytarabine + anthracycline (“7+3" protocol).

Targeted therapies (treatments based on the genetics of leukemia)

One targeted therapy is a drug treatment that specifically targets genetic or molecular abnormalities or alterations present in cancer cells or other diseased cells.

Unlike conventional treatments such as chemotherapy that act on all cells in the body, targeted therapies work more selectively, by blocking or inhibiting specific proteins involved in the growth and proliferation of cancer cells or in other diseases.

Targeted therapies are often used in combination with other treatments such as chemotherapy or radiation therapy. They are being used more and more in the treatment of cancer.

In the case of acute leukemias, here are the most used targeted therapies:

Immunotherapy (stimulates the immune system against leukemia cells)

Immunotherapy is a treatment that stimulates or changes the immune system to help fight cancer. It uses antibodies, vaccines, or other agents to enhance the body’s ability to detect and destroy cancer cells. This treatment can be used alone or in combination with other treatments such as surgery, chemotherapy, or radiation therapy.

It is used for LAL, especially if chemotherapy treatment is unsuccessful. Among the immunotherapies used, we find:

Monoclonal antibodies

• Blinatumomab (anti-CD19) : Stimulates the immune system against leukemic B cells.
• Inotuzumab ozogamicin (anti-CD22) : Targets B cells.

CAR-T therapy (laboratory modified T cells)

• Tisagenlecleucel (Kymriah) : Reserved for patients with relapsed LAL-B.

Bone marrow transplant (hematopoietic stem cell transplantation)

The aim of bone marrow transplantation is to replace diseased bone marrow with healthy marrow. It is used in case of relapses or for high-risk leukemias. There are two types of transplants:

• Allogeneic graft (marrow from a compatible donor)
• Autologous transplant (patient’s marrow after intensive chemotherapy)