TIL Therapy: Your Immune Cells,
Already Fighting Your Cancer.

TIL (Tumor-Infiltrating Lymphocyte) therapy is a type of adoptive cell transfer immunotherapy. It uses the patient's own immune cells that have already recognized and infiltrated their tumor. A piece of tumor is surgically removed, TILs are isolated and expanded in the lab with interleukin-2 (IL-2) over 3-5 weeks to reach billions of cells, then reinfused after lymphodepleting chemotherapy. This approach leverages the natural anti-tumor immunity already present in the tumor microenvironment.

Yes. On February 16, 2024, the FDA approved lifileucel (brand name Amtagvi, developed by Iovance Biotherapeutics) for adult patients with unresectable or metastatic melanoma previously treated with a PD-1 blocking antibody, and if BRAF V600 mutation positive, a BRAF inhibitor with or without a MEK inhibitor. This was the first FDA-approved TIL therapy and the first cell therapy approved for any solid tumor.

In the C-145-04 pivotal trial published in NEJM (2023), lifileucel achieved an objective response rate (ORR) of 36% in 153 patients with advanced melanoma who had progressed on prior immunotherapy and targeted therapy. Complete response (CR) was observed in 11% of patients. Among responders, the duration of response was durable, with 85% of responses lasting 6 months or longer, and many exceeding 2 years.

In the USA, the list price for lifileucel (Amtagvi) is approximately $375,000, not including hospital fees, lymphodepletion chemotherapy, IL-2 administration, and ICU monitoring, which can bring the total episode of care to $500,000+. In China, TIL therapy is available through clinical research programs at $80,000-$120,000. In Singapore, costs range from $100,000-$150,000. These prices reflect self-pay international patient pricing.

Ideal candidates have unresectable or metastatic melanoma that has progressed after PD-1 inhibitor therapy (and BRAF/MEK inhibitors if BRAF V600-mutated). Patients must have ECOG performance status 0-1, adequate organ function (heart, lungs, liver, kidneys), and a resectable tumor site for TIL harvest. Active uncontrolled infection, severe autoimmune disease, or need for chronic immunosuppression are contraindications.

TIL therapy has two distinct phases of side effects: (1) Lymphodepletion chemotherapy (typically cyclophosphamide + fludarabine) causes prolonged cytopenias, infection risk, and fatigue for 1-2 weeks. (2) High-dose IL-2 support (up to 12 doses) can cause capillary leak syndrome with hypotension, edema, and requires ICU-capable monitoring. Other common effects include fever, chills, nausea, and transient liver enzyme elevation. Most side effects are manageable in experienced centers.

The full TIL therapy timeline is typically 6-10 weeks: Week 1 — surgical tumor resection and tissue shipping; Weeks 2-6 — TIL isolation and expansion in the GMP lab (22-33 days); Week 6-7 — patient admission, lymphodepleting chemotherapy (2-3 days); Week 7 — TIL infusion day; Weeks 7-8 — IL-2 support (up to 12 doses over 5 days) and recovery monitoring. Total hospital stay is typically 2-3 weeks.

While FDA approval is currently limited to melanoma, TIL therapy is being actively investigated in clinical trials for cervical cancer (with promising Phase 2 data showing 44% ORR in PD-1 refractory patients), head and neck cancers, non-small cell lung cancer, breast cancer, and gastrointestinal cancers. Iovance is running the C-145-06 trial in cervical cancer. Access to TIL for non-melanoma indications is currently through clinical trials in China, Singapore, and select US academic centers.