Interleukin 12 Gene Therapy of Cancer by Peritumoral Injection of Transduced Autologous Fibroblasts: Outcome of a Phase I Study

Abstract

A phase I dose-escalation clinical trial of peritumoral injections of interleukin 12 (IL-12)-transduced autologous fibroblasts was performed in patients with disseminated cancer for whom effective treatment does not exist. The goals of this study were to assess the safety and toxicities as well as the efficacy, and ancillarily the immunomodulatory effects, of peritumoral IL-12 gene transfer. Primary dermal fibroblasts cultured from the patients were transduced with retroviral vector carrying human IL-12 genes (p35 and p40) as well as the neomycin phosphotransferase gene (TFG-hIL-12-Neo). Patients received four injections at intervals of 7 days. Nine patients were enrolled in this dose-escalation study, with secreted IL-12 doses ranging from 300 ng/24 hr for the first three patients to 1000, 3000, and 5000 ng/24 hr for two patients in each subsequent dosage level. Although a definite statement cannot be made, there appears to be perturbation of systemic immunity. Also, the locoregional effects mediated by tumor necrosis factor alpha (TNF-alpha) and CD8+ T cells were observed with tumor regression. Treatment-related adverse events were limited to mild to moderate pain at the injection site; clinically significant toxicities were not encountered. Transient but clear reductions of tumor sizes were observed at the injected sites in four of nine cases, and at noninjected distant sites in one melanoma patient. Hemorrhagic necrosis of tumors was observed in two melanoma patients. These data indicate that gene therapy by peritumoral injection of IL-12-producing autologous fibroblasts is feasible, and promising in patients with advanced cancer.

Preclinical study of an ex vivo gene therapy protocol for hepatocarcinoma

“…Furthermore, the therapeutic genetically modified autologous fibroblasts used in this technique have already been validated in two clinical trials. 21 Elder et al 30 have earlier shown the successful culturing, expansion and genetic modification of human fibroblasts to produce IL-4 and IL-12. They also showed that dermal fibroblasts can be easily obtained and cultured from nearly all individuals using a simple procedure combining hyaluronidase and collagenase treatment.…”

“…The ex vivo strategy using fibroblasts transduced with a rv vector encoding hIL-12 has been validated earlier in Elaboration of an ex vivo gene therapy protocol B Lortal et al clinical trials of patients with cancer by both Lotze et al 31 and Kang et al 21 The two teams used the same rv vector, an MFG-based rv plasmid constructed by L Zitvogel et al, 33 containing the two subunits of IL-12 (p35 and p40) as well as the neomycin resistance selectable marker gene (NeoR). The viral particles were derived from the packaging cell line, cCRIP, 34 which gives recombinant retrovirus with amphotropic host ranges (env gene from the 4070A virus genome).…”

“…16,17 On the basis of the promising results obtained in a large series of preclinical IL-12 gene therapy studies, 8 clinical trials have been designed with the aim of achieving cytokine production at the tumor site, while at the same time maintaining low serum concentrations to reduce systemic toxicity. [18][19][20][21] Various strategies involving immune stimulation have shown occasional activity against HC leading to the execution of phase I immuno gene therapy involving IL-12 trials in relation to HC treatments. Sangro et al 19,20 and Mazzolini et al 22 have evaluated the feasibility and safety of the intratumoral injection of an adenoviral vector encoding IL-12 or autologous dendritic cells transduced with an adenovirus encoding IL-12, respectively.…”

“…They can be used, for example, to cure diseases such as junctional epidermolysis bulbosa, 25 treat venous, diabetic and pressure ulcers by the release of growth factors or cytokines (vascular endothelial growth factor (VEGF), hepatocyte growth factor, basic fibroblast growth factor (FGF), transforming growth factor (TGF) b1 and IL-8), 26 increase tissue repair in acute or chronic wounds and in aesthetic and reconstructive surgery, 27 and treat Duchenne muscular dystrophy, 25 Alzheimer's disease 28 or cancer by the induction of an immune response. 21,29 Fibroblasts are mostly obtained from skin biopsies varying in size from one clinical trial to another. 21,28 They can be harvested by direct culture or enzymatic digestion of the biopsy, transduced using non-viral or viral vectors, selected with G418 28 and then extensively cultured to obtain a number of fibroblasts sufficient to produce the required drug dose.…”

“…21,29 Fibroblasts are mostly obtained from skin biopsies varying in size from one clinical trial to another. 21,28 They can be harvested by direct culture or enzymatic digestion of the biopsy, transduced using non-viral or viral vectors, selected with G418 28 and then extensively cultured to obtain a number of fibroblasts sufficient to produce the required drug dose. Cells have to be frozen and thawed without affecting their potency as drug vehicles and are mostly irradiated to ensure growth arrest.…”