Doctors are developing new immunotherapy treatments for certain types of blood cancer such as leukemia, alongside expanding treatment options to provide hope for patients who have not seen progress with other therapies. The term "leukemia" refers to a group of malignant tumors characterized by the rapid and uncontrolled growth of abnormal blood cells, known as leukemia cells. According to the World Cancer Research Fund, this disease can affect both children and adults, ranking 13th among the most common types of cancer worldwide.
**Significant Shift in Treatment**
The use of chimeric antigen receptor T-cell therapy (CAR T) contributes to a notable transformation in the treatment landscape, offering many patients with blood cancers like leukemia the hope of a permanent cure, according to Dr. Jean Joseph Milinhorst, a specialist in immunotherapy and the director of a newly established cellular therapy and immunological engineering program at Cleveland Clinic. This specialized treatment relies on using the patient’s own T-cells — a type of white blood cell that is part of the immune system. During the treatment program, the T-cells are extracted, genetically modified so they can recognize and destroy cancer cells before they can multiply and re-enter the bloodstream.
**Numerous Challenges Ahead for This Treatment**
However, there are still many challenges to overcome in managing this treatment, particularly regarding its costs, which may be higher compared to other therapies. Additionally, this type of treatment may have serious side effects. This could limit accessibility to the treatment, necessitating that it be administered to inpatients in a specialized center where potential side effects can be managed effectively.
**Option After Chemotherapy Failure**
Cytotoxic chemotherapy remains the primary standard of care in the initial treatment of many patients with acute blood cancers or leukemia, aimed at aiding their recovery. In cases where first-line chemotherapy or other treatments fail, CAR T therapy provides another potential treatment option for patients with acute lymphoblastic leukemia (ALL). According to FDA-approved indications, this therapy has proven to be more effective than the former standard, which involved another round of chemotherapy.
The U.S. Food and Drug Administration has approved commercial products for CAR T-cell therapy for various types of blood cancer, including acute lymphoblastic leukemia (ALL) in patients who have not responded to other treatments or who have relapsed after a period of remission.
**Classification of Leukemia**
Leukemia is classified as either "acute" or "chronic" based on the speed of disease progression in the body, and it is categorized as "myeloid" or "lymphoid" depending on whether the leukemia cells originate from myeloid cells, which develop in the bone marrow, or from lymphoid cells, which are associated with the immune system.
**Extraction of Lymphocytes: Treatment Steps**
Dr. Souter explained that the first step in the CAR T-cell therapy program involves extracting lymphocytes from the patients, followed by introducing an inactive virus that provides new genetic instructions to the T-cells to start producing chimeric antigen receptors targeting proteins that reside on malignant cells. Researchers then take a small batch of newly modified T-cells and stimulate them to grow and multiply until there are enough to effectively target cancer cells. The doctors then freeze these cells and store them until the patient is ready to receive them. During the preparation process for the intravenous infusion of the treatment, the patient is given a mild form of chemotherapy to prevent the immune system from rejecting the CAR T-cells.
**Key Side Effects**
Dr. Souter noted that most patients need to stay in the hospital for one to two weeks so that their response to the treatment can be monitored and any side effects managed. Cytokine release syndrome (CRS) and neurological issues such as headaches, confusion, or difficulty speaking during treatment are among the most common side effects associated with CAR T-cell therapy.
