Virus-directed enzyme prodrug therapy: intratumoral administration of a replication-deficient adenovirus encoding nitroreductase to patients with resectable liver cancer.

PURPOSE Virus-directed enzyme prodrug therapy depends on selective delivery of virus encoding a prodrug-activating enzyme to tumor, followed by systemic treatment with prodrug to achieve high levels of the activated cytotoxic at the intended site of action. The use of the bacterial enzyme nitroreductase to activate CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) to a short lived, highly toxic DNA cross-linking agent has been demonstrated in tumor xenografts. In this study, we report the first clinical trial investigating the feasibility, safety, and transgene expression of a replication-defective adenovirus encoding nitroreductase (CTL102) in patients with liver tumors. PATIENTS AND METHODS Patients with resectable primary or secondary (colorectal) liver cancer received a single dose of CTL102 delivered by direct intratumoral inoculation 3 to 8 days before surgical resection. RESULTS Eighteen patients were treated with escalating doses of CTL102 (range, 10(8)-5 x 10(11) virus particles). The vector was well tolerated with minimal side effects, had a short half-life in the circulation, and stimulated a robust antibody response. Dose-related increases in tumoral nitroreductase expression measured by immunohistochemical analysis have been observed. CONCLUSION Direct intratumoral inoculation of CTL102 to patients with primary and secondary liver cancer is feasible and well tolerated. The high level of nitroreductase expression observed at 1 to 5 x 10(11) virus particles mandates further studies in patients with inoperable tumors who will receive CTL102 and CB1954.

[1]  D. Kerr,et al.  Expression of Escherichia coli B nitroreductase in established human tumor xenografts in mice results in potent antitumoral and bystander effects upon systemic administration of the prodrug CB1954 , 2000, Cancer Gene Therapy.

[2]  I. McNeish,et al.  Virus directed enzyme prodrug therapy for ovarian and pancreatic cancer using retrovirally delivered E. coli nitroreductase and CB1954 , 1998, Gene Therapy.

[3]  D. McDonald,et al.  Coxsackie and adenovirus receptor (CAR)-dependent and major histocompatibility complex (MHC) class I-independent uptake of recombinant adenoviruses into human tumour cells , 1999, Gene Therapy.

[4]  D. Kerr,et al.  Combined adenovirus-mediated nitroreductase gene delivery and CB1954 treatment: a well-tolerated therapy for established solid tumors. , 2001, Molecular therapy : the journal of the American Society of Gene Therapy.

[5]  D. Kerr,et al.  Virus-directed, enzyme prodrug therapy with nitroimidazole reductase: a phase I and pharmacokinetic study of its prodrug, CB1954. , 2001, Clinical cancer research : an official journal of the American Association for Cancer Research.

[6]  F. Friedlos,et al.  CB 1954 (2,4-dinitro-5-aziridinyl benzamide) becomes a DNA interstrand crosslinking agent in Walker tumour cells. , 1986, Biochemical and biophysical research communications.

[7]  S. White,et al.  THE STRUCTURE OF ESCHERICHIA COLI NITROREDUCTASE COMPLEXED WITH NICOTINIC ACID , 2001 .

[8]  F. Friedlos,et al.  The bioactivation of 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954)--II. A comparison of an Escherichia coli nitroreductase and Walker DT diaphorase. , 1992, Biochemical pharmacology.

[9]  A. van der Eb,et al.  New helper cells and matched early region 1-deleted adenovirus vectors prevent generation of replication-competent adenoviruses. , 1998, Human gene therapy.

[10]  J. Roberts,et al.  The differences in kinetics of rat and human DT diaphorase result in a differential sensitivity of derived cell lines to CB 1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) , 1991, Biochemical pharmacology.

[11]  S. White,et al.  The structure of Escherichia coli nitroreductase complexed with nicotinic acid: three crystal forms at 1.7 A, 1.8 A and 2.4 A resolution. , 2001, Journal of molecular biology.

[12]  D. Kerr,et al.  Sensitisation of human carcinoma cells to the prodrug CB1954 by adenovirus vector‐mediated expression of E. coli nitroreductase , 2000, International journal of cancer.

[13]  K. Willecke,et al.  Bystander killing of cancer cells by herpes simplex virus thymidine kinase gene is mediated by connexins. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[14]  J. J. Roberts,et al.  The nitroreductase enzyme in Walker cells that activates 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) to 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide is a form of NAD(P)H dehydrogenase (quinone) (EC 1.6.99.2). , 1988, Biochemical pharmacology.

[15]  V. Mautner,et al.  Neutralisation of adenovirus infectivity by ascitic fluid from ovarian cancer patients , 2000, Gene Therapy.

[16]  C. Springer,et al.  The bystander effect of the nitroreductase/CB1954 enzyme/prodrug system is due to a cell-permeable metabolite. , 1997, Human gene therapy.

[17]  C. Springer,et al.  Expression of the bacterial nitroreductase enzyme in mammalian cells renders them selectively sensitive to killing by the prodrug CB1954. , 1995, European journal of cancer.