Published on August 06, 2026
Real-World Tumor-Infiltrating Lymphocyte Therapy for Metastatic Melanoma: Treatment Delivery, Immune Reconstitution, and Cardiac Monitoring During High-Dose IL-2
by Alex Kadhim
Of 45 adults with metastatic melanoma who underwent tumor procurement across three Mayo Clinic sites between April 2024 and December 2025, 36 proceeded to tumor-infiltrating lymphocyte (TIL) infusion. This retrospective analysis, published in Current Oncology, reports treatment delivery, clinical outcomes, immune reconstitution, and cardiac monitoring during high-dose interleukin-2 (IL-2). The authors report meaningful antitumor activity including complete responses, shorter survival among patients with central nervous system metastases, and prolonged CD4 lymphopenia, and identify high-sensitivity troponin as a candidate marker for guiding IL-2 administration.
TIL therapy requires tumor collection, ex vivo lymphocyte expansion, lymphodepleting chemotherapy, cell infusion, and high-dose IL-2, making its delivery outside clinical trials operationally complex. Seven of the 36 infused patients received out-of-specification products under single-patient investigational authorization. Patients had received a median of three previous treatment lines, 55.6% required bridging therapy, and the median harvest-to-infusion interval was 50 days. Clinical outcomes, toxicities, and IL-2 delivery were recorded, while longitudinal CD4 and CD8 counts, CD4:CD8 ratio, and immunoglobulin G measurements assessed immune reconstitution.
The objective response rate was 50.0%, with complete responses in 13.9% and a disease control rate of 72.2%. Median progression-free survival was 3.61 months and median overall survival 12.94 months. Patients with M1d disease had shorter overall survival than those without central nervous system involvement (4.57 vs 13.40 months; p<0.001). CD4 counts remained significantly suppressed through month 6 (all p<0.001), falling below 200 cells/µL in 60% of patients at month 1, 81% at month 3, and 90% at month 6; immunoglobulin G also declined at months 3 and 6. A post-dose troponin of 15 ng/L or higher was associated with cardiac events (OR 9.6; p=0.016) and IL-2 interruption (OR 3.4; p=0.036), with 100% sensitivity and negative predictive value for cardiac events. Real-world TIL therapy therefore appears feasible and active, but requires careful patient selection, biomarker-guided IL-2 monitoring, and prolonged follow-up of immune recovery.
Reference:
Aboelatta MA, Zarka J, Tchatchua N, et al. Real-World Tumor-Infiltrating Lymphocyte Therapy for Metastatic Melanoma: Treatment Delivery, Immune Reconstitution, and Cardiac Monitoring During High-Dose IL-2. Curr Oncol. 2026;33(7):379. Published 2026 Jun 24. https://doi.org/10.3390/curroncol33070379
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