Oncologist Answers Most Common Questions About Cell Therapy

Dr. Muhammad Tariq, a hematology oncologist at the University of Florida Health, works at the forefront of cell therapy — one of the fastest-evolving areas in cancer treatment. As more patients are diagnosed with blood cancers and other malignancies, questions about this innovative approach to fighting cancer are becoming increasingly common. Dr. Tariq sat down with CURE® to break down what cell therapy is, who it helps, and what patients need to know before starting treatment.

Cure: What is cell therapy, and how does it help the body's immune system fight cancer?

Tariq: Cell therapies are new types of cancer treatments in which live immune cells are taken from either the patient's own body or from a donor, then genetically engineered to fight a specific type of cancer. Once returned to the body, these engineered cells activate the immune system and specifically target cancer cells — the very cells that are normally not responding to chemotherapy or other drugs.

Which cancers currently have approved cell therapy treatments?

Right now, cell therapy approvals are mainly in blood cancers: B-cell lymphomas, B-acute lymphoblastic leukemia (B-ALL), and multiple myeloma. We also have approvals in two solid tumors — melanoma, using a treatment called tumor-infiltrating lymphocytes (TIL), and synovial sarcoma. In blood cancers, we have four approved products for diffuse large B-cell lymphoma, three for B-ALL, and two for multiple myeloma. For melanoma and synovial sarcoma, there is currently one approved product each. These therapies are approved both in the second line of treatment and in later lines, meaning patients who have already tried other therapies may still be candidates.

Who may be a candidate for cell therapy, and how do doctors determine whether it is the right treatment option?

Patients who do not respond well to chemotherapy, or who relapse within the first year of receiving it, are candidates for cell therapy. Their primary doctor should refer them to a cell therapy center promptly, because the process requires a great deal of planning — from insurance approval to cell collection to sending the cells to a manufacturing company, which can take anywhere from two to six weeks. That is why timely referral is so important. All patients with blood cancer should ask their doctors about approved cell therapy options as well as any available clinical trials. We currently have trials underway in acute myeloid leukemia, breast cancer, GI cancers, pancreatic cancer, and brain tumors, so there may be options even beyond currently approved treatments.

Is cell therapy typically used as an initial treatment, or is it considered after other therapies have been tried?

Currently, cell therapy is used as a second-line or later treatment. Patients typically receive chemotherapy first, and if it does not work — or if they relapse shortly after — they become potential candidates for CAR-T or other cell therapies. There are clinical trials exploring the use of cell therapy in frontline settings, but those still involve receiving one or two cycles of chemotherapy first, largely because cell therapy takes time to manufacture and it is critical to keep the disease in control while patients are waiting. Official FDA approval for frontline use does not yet exist, and results from those trials are still pending.

How does cell therapy differ from other cancer treatments like chemotherapy, radiation, and immunotherapy?

The most important difference is that cell therapy uses living drugs. In CAR-T cell therapy, T cells are collected and a new receptor is genetically engineered onto their surface, allowing them to recognize and attack cancer cells. In melanoma treatment, tumor-infiltrating lymphocytes — white cells that naturally fight the tumor — are harvested, expanded in a lab, and given back to the patient. Before receiving any of these cell therapies, patients first undergo a process called lymphodepletion using chemotherapy agents, which prepares the body to receive the new cells. Those live cells then expand inside the body and specifically target cancer cells. Because it is a living treatment that can persist in the body, cell therapy is generally a one-time infusion — a significant distinction from traditional chemotherapy, which must be given repeatedly at regular intervals since its effects do not last on their own.

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