Tumor-Infiltrating Lymphocyte (TIL) Therapy


Tumor-infiltrating lymphocyte (TIL) therapy is a type of cancer treatment where white blood cells, called TILs, are removed from a patient's tumor, grown and fed in a lab, and then infused back into the patient to fight the cancer.

Currently, TIL therapy is FDA-approved for relapsed or refractory melanoma. It is being tested in clinical trials for other types of cancer.

What Are Tumor-Infiltrating Lymphocytes (TILs)?

T lymphocytes, or T Cells, are white blood cells that fight infection and illness, such as cancer. When found in a tumor, these white blood cells are the tumor-infiltrating lymphocytes (TILs) used in TIL therapy. Because TILs are in tumors, these white blood cells already recognize many targets on the cancer cells. To make them more effective in fighting cancer, after the TILs are removed from a patient’s tumor, they are multiplied and activated in a lab and then re-infused back into the patient to help attack their cancer.

Understanding TIL Therapy: How Does It Work? 

TIL therapy uses a sample of a patient’s tumor to create cancer-fighting cells. The typical steps in TIL therapy are:

Remove Tumor Sample 

In the first step of TIL therapy, a surgeon removes (or “resects”) a portion of the tumor.

Extract, Grow, and Multiply TILs (TILs Production)

After surgery, the tumor sample is sent to a special lab where it is broken up into fragments to remove the TILs present in the tumor tissue. The TILs are then grown in the lab with interleukin-2 (IL-2), a protein that boosts cell growth, reproduction, and ability to fight cancer. Over time, the TILs multiply and the tumor cells die off, leaving billions of TILs that recognize that patient’s cancer.

Bridging Therapy

While the TILs are being made, patients receive bridging therapy to treat and manage their disease.

Preparative Chemotherapy

Patients receive a short course of chemotherapy to make room in their immune system for the TILs to expand and multiply.

TIL Infusion

Patients are admitted to Brigham and Women’s Hospital for their TIL infusion. TILs are infused through a central line.

Interleukin-2 Infusions

After the TIL infusion, patients receive several doses of interleukin-2 (IL-2), a medicine that helps boost, expand, and activate the number of TILs in their bodies. The IL-2 infusions are usually given for three to five days, depending on how a patient responds to the treatment.

Follow-Up Care

Patients have a follow-up appointment at Dana-Farber one month after their TIL infusion. Then, they will have appointments with scans every three months for a period of time to monitor their health and response to TIL therapy.

Success Rate and Side Effects: What Can I Expect After TIL Therapy?

TIL therapy has shown benefits in patients with some types of cancer whose disease has returned after treatment or has not responded to other treatments. Clinical trials show it may reduce tumor size and slow tumor growth.

TIL therapy is generally well tolerated. Patients may have side effects from the preparative chemotherapy and the IL-2. Side effects may include:

  • Fever
  • Fatigue
  • Low blood pressure
  • Temporary lab abnormalities (e.g., electrolyte abnormalities)
  • Confusion
  • Swelling due to fluid retention
  • Low blood cell counts

Resources and Support for Patients

At Dana-Farber Brigham Cancer Center, patients receive outstanding care from experts in their disease type and cellular therapies. The care team includes a disease-specific oncologist, surgeon, nurse practitioner or physician assistant, and oncology nurse navigators. Patients also receive support from financial counselors, social workers, clinical coordinators, and resource specialists. 

Explore support services and resources we offer to help patients on their treatment journey.