FDA Approves First Tumor-infiltrating Lymphocyte Therapy 

The FDA has granted accelerated approval to lifileucel, a new type of cell therapy, for the treatment of melanoma.

The U.S. Food and Drug Administration (FDA) has granted accelerated approval to lifileucel (Amtagvi) for the treatment of adult patients with unresectable or metastatic melanoma that has been previously treated with a PD-1 inhibitor and, if eligible, a BRAF inhibitor. 

Lifileucel is a type of immunotherapy known as tumor-infiltrating lymphocyte (TIL) therapy. Briefly, T cells are harvested from a sample of a patient’s tumor, expanded in the laboratory, and infused back into the patient. Because these T cells were found inside the tumor, they are likely to have characteristics that optimize them for killing the cancer. 

Illustration of white T cells, which are harvested from a patient’s tumor to produce TIL therapy.
Lifileucel, recently approved by the FDA, is composed of T cells such as these that were harvested from a patient’s tumor.

Lifileucel is the first TIL therapy to be approved by the FDA. 

This approval was based on results from a global, multicenter, multicohort, open-label, single-arm, phase II clinical trial that enrolled 89 patients with unresectable or metastatic melanoma who had previously received at least one prior therapy—including a PD-1 inhibitor—as well as a BRAF inhibitor (with or without a MEK inhibitor) if eligible. Patients received lymphodepleting chemotherapy followed by lifileucel then infusions of aldesleukin, an analog of the immune-regulating protein interleukin-2, to help the infused cells expand in the body. 

Among 73 patients who received lifileucel in the recommended dosing range, the objective response rate was 31.5%, and the median duration of response was not reached. 

It is recommended that lifileucel be administered as a single infusion of 7.5×109 to 72×109 viable cells.  

The prescribing information contains a boxed warning for treatment-related mortality, prolonged severe cytopenia, severe infection, cardiopulmonary impairment, and renal impairment. 

Melanoma is a rare but aggressive skin cancer that arises from the cells that give your skin its pigment. According to federal statistics, it was estimated that 97,610 individuals would be diagnosed with melanoma and 7,990 patients would die of the disease in the United States in 2023. 

The FDA rendered its decision on February 16, 2024. Accelerated approval means that continued approval may be contingent upon a confirmatory trial.