Immunology and Biotherapies

#TIL's Genetically #Engineered w/Inducible Gene Encoding IL-12 for #Immunotherapy of Metastatic #Melanoma http://t.co/ABuiy4QodT #health

 

Abstract

Purpose: Infusion of interleukin-12 (IL-12) can mediate anti-tumor immunity in animal models, yet its systemic administration to patients with cancer results in minimal efficacy and severe toxicity. Here, we evaluated the anti-tumor activity of adoptively transferred human tumor infiltrating lymphocytes (TIL) genetically engineered to secrete single-chain IL-12 selectively at the tumor site. Experimental Design:Thirty-three patients with metastatic melanoma were treated in a cell-dose escalation trial of autologous TIL transduced with a gene encoding a single chain IL-12 driven by a nuclear factor of activated T cells promoter (NFAT.IL12). No IL-2 was administered. Results:The administration of 0.001-0.1 X 109 NFAT.IL12 transduced TIL to 17 patients resulted in a single objective response (5.9%). However, at doses between 0.3-3 X 109 cells, 10 of 16 patients (63%) exhibited objective clinical responses. The responses tended to be short and the administered IL-12 producing cells rarely persisted at one month. Increasing cell doses were associated with high serum levels of IL-12 and gamma-interferon as well as clinical toxicities including liver dysfunction, high fevers and sporadic life threatening hemodynamic instability. Conclusions:In this first-in-man trial, administration of TIL transduced with an inducible IL-12 gene mediated tumor responses in the absence of IL-2 administration using cell doses 10-100 fold lower than conventional TIL. However, due to toxicities, likely attributable to the secreted IL-12, further refinement will be necessary before this approach can be safely utilized in the treatment of cancer patients.