Cell therapy: The evolution of the ¡®living drug¡¯
BY Jade Waddy
April 22, 2025
Medically Reviewed | Last reviewed by on April 22, 2025
For decades, researchers have been exploring ways to harness the power of the immune system to treat cancer. One breakthrough is cell therapy, often called 'living drugs.' This is a form of immunotherapy that uses immune cells from a patient or a healthy donor. With advanced engineering techniques, scientists enhance these cells to recognize better and attack cancer.
¡°During the late 1980s and 1990s, cancer researchers started exploring ways to advance immunotherapy by transferring immune cells into a patient to attack cancer cells,¡± says stem cell transplant and cellular therapy specialist ¡°They recognized that immune cells found inside tumors could help destroy cancer cells, leading to the development of one of the earliest forms of cell therapy ¡ª tumor-infiltrating lymphocytes (TILs).¡±
Currently approved types of cell therapy
There are currently three types of cell therapy that have been approved to treat certain cancers by the Food and Drug Administration (FDA).
Tumor-Infiltrating Lymphocyte (TIL) therapy
TIL therapy is one of the earliest forms of cell therapy. It involves extracting immune cells from a patient¡¯s tumor, growing them and enhancing them outside the body with small proteins called cytokines. Once reinfused into the patient, the goal is for them to expand rapidly and attack cancer cells. TIL therapy is primarily used to treat solid tumors, particularly melanomas. In 2024, the Food and Drug Administration (FDA) approved the first TIL therapy, marking a significant milestone in cancer treatment.
T cell receptor (TCR) cell therapy
T cells are collected from a patient and genetically modified to detect specific protein fragments, or peptides, displayed on the surface of cancer cells. These peptides are presented by molecules called human leukocyte antigens (HLAs), which act like a cellular ID card, helping the immune system distinguish between healthy and abnormal cells. Once infused back into the patient, the engineered T cells recognize these peptides, bind to the HLA molecules, and launch an attack on the cancer cells. The FDA approved the first TCR therapy in 2024 for synovial sarcoma, a rare soft-tissue cancer, marking a major advancement in precision cancer treatment.
Chimeric antigen receptor T cell therapy (CAR T cell therapy)
CAR T cell therapy has revolutionized cancer treatment in recent years. Unlike TCR therapy, which modifies T cells to recognize specific peptides presented by each patient¡¯s unique cellular ID cards called HLA molecules, CAR T cell therapy engineers T cells to directly bind to cancer cell surface proteins. This means it can be used to treat far more patients. ¡°With CAR T cell therapy, we can precisely and powerfully target cancer cells through these CARs,¡± Rafei says. Since 2017, seven CAR T cell therapies have been approved by the FDA for some blood cancers such as multiple myeloma, large B-cell lymphoma, and mantle cell lymphoma. Many of these approvals have been based on clinical trials led by MD Anderson researchers.
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CAR NK cell therapy offers off-the-shelf treatment option
Current cell therapies have one thing in common: they all rely on autologous cells, or cells from a patient¡¯s tumor or blood. While these therapies have revolutionized treatment for some cancer types, there are still challenges, such as long production times and high costs.
¡°Patients often need treatment right away, but making these cell therapies can take weeks,¡± Rafei says. ¡°So, there's a huge need for ready-to-use options that can help more patients."
Several cell therapy clinical trials at MD Anderson have focused on allogenic cells, or cells from another source, such as donated blood or cord blood. One promising type of allogeneic cells is natural killer (NK) cells, a key part of the immune system. Unlike T cells, which must be trained to recognize and attack cancer, NK cells naturally identify and destroy foreign cells. ¡°We can make CAR NK cells ready and use them right away to fight cancer,¡± says Rafei. ¡°And so far, we haven't seen any severe toxicities with them, which is a major breakthrough.¡±
Researchers can enhance and engineer NK cells with a CAR, creating powerful CAR NK cells. They have developed a way to safely freeze these cells that does not impact their efficacy and so that they are readily available for patients off-the-shelf. This means patients who need them can often start treatment right away. In addition, researchers examined and found that CAR NK cells engineered to express interleukin 15 extended the lifespan of the powerful cells in a patient¡¯s body.
Next phase of cell therapies
Researchers are now expanding cell therapeutics to treat solid cancers by better understanding ways to overcome their unique challenges, such as the tumor microenvironment. Last fall, MD Anderson launched its Institute for Cell Therapy Discovery & Innovation, which is pioneering and advancing cell therapies for patients. The institute will enable scientists and clinicians to investigate cell therapy in the treatment of not only cancer but also autoimmune diseases, infections and other conditions.
¡°Cell therapies have already made a tremendous impact on patients, and we are now starting to write the next exciting chapter at the Institute,¡± Rafei says. ¡°With the speed at which we¡¯re making new discoveries, the potential ahead is limitless.¡±
Learn more about the Institute for Cell Therapy Discovery & Innovation.
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TreatmentThere's a huge need for ready-to-use options that can help more patients.
Hind Rafei, M.D.
Physician