Defining Surgical Success for TIL Therapy in Metastatic Melanoma
Metastatic melanoma is a late-stage form of skin cancer that has spread to other parts of the body beyond its initial site.
In addition to traditional treatments like surgery, chemotherapy and radiation, a cellular immunotherapy called tumor-infiltrating lymphocyte (TIL) therapy has been approved by the U.S. Food and Drug Administration to treat advanced disease.
The therapy uses a patient’s own immune cells to fight cancer, an approach similar to other forms of cellular immunotherapy, but the unique aspect of TIL therapy is that the immune cells are derived from the tumor itself. This means that surgery is required to obtain a tumor sample for TIL therapy.
At the Society of Surgical Oncology 2026 Annual Meeting, Amod Sarnaik, MD, a surgical oncologist in the Cutaneous Oncology Department at Moffitt Cancer Center, delivered a presentation breaking down how the therapy works.
Step 1: T cells are selected
One or more tumors are surgically removed from the patient, and T cells are then grown from the tumor in sterile conditions in a specialized laboratory setting.
Step 2: Large-scale expansion
The T cells, which seek out and destroy abnormal cells, divide rapidly until the total amount reaches billions of cells. This process is completed in a highly regulated sterile laboratory setting and can take a month or longer.
Step 3: Reinfusion
The cells are then infused back into the patients, aimed at seeking out and destroying the patient’s cancer.
Live from #SSO2026: Amod Sarnaik, MD, reviews the development of TIL therapy, including data supporting lifileucel in advanced melanoma, and highlights the critical role of surgical tumor harvest and emerging strategies to enhance efficacy and reduce toxicity.
— Moffitt Cancer Center (@MoffittNews) March 6, 2026
Key takeaways:… pic.twitter.com/paYGQ6CkRh
Partnering With Other Centers
TIL therapy requires surgical tumor tissue procurement (TTP) for product manufacturing. Despite many decades of data about the effect of TIL therapy, there is very little published data regarding the optimal surgical approach. As the lead site for the initial publication on this topic, Moffitt has joined several other institutions to form The TIL TTP Working Group to gain more information about how surgical factors influence TIL manufacturing success.
According to John Mullinax, MD, a surgical oncologist in Moffitt’s Sarcoma Department and the surgical director of the Immune Cell Therapy (ICE-T) program, the initial goal is to define factors that would predict failure of TIL growth from resected tumors.
“There is something called ‘out of spec’, which happens when the TIL do not expand during manufacturing after the tumor is removed. Ultimately, the manufacturing process fails and therefore the patient does not receive their treatment,” Mullinax explained. “Through identification of key factors, we are trying to reduce the number of out-of-spec cases. It’s about 20% across all sites offering this treatment and we think we can reduce that rate through identification of tumor and patient factors.”
Between December 2023 and August 2025, the study analyzed information from 87 patients across six different institutions who underwent surgical tumor tissue procurement, with the largest number of patients supplied by Moffitt. Eighty-five percent of the cases resulted in manufacturing success, and there were early signals of factors that might predict an out of spec product.
“You need a large number of patients to have the power to understand the statistical difference between patient outcomes and therefore studies like this are only possible through collaboration. Our findings will help us continue to improve TIL therapy for future patients,” Mullinax said.
During #SSO2026: John Mullinax, MD (@JohnEMullinaxMD), and Luke Selby, MD, of @UnivOfKansas, discuss collaboration in TIL therapy research, highlighting how partnerships around tumor-infiltrating lymphocytes and tissue procurement can help advance progress in sarcoma. pic.twitter.com/mmwImL9Xm9
— Moffitt Cancer Center (@MoffittNews) March 6, 2026
