Phase I Trial of Interferon gamma Retroviral Vector Administered Intratumorally with Multiple Courses in Patients with Metastatic Melanoma

Abstract

The purpose of this study was to determine the safety and antitumor activity of IFN-gamma retroviral vector in patients with advanced melanoma. Seventeen patients (9 single courses, 8 multiple courses) received a total of 363 intratumor injections of IFN-gamma retroviral vector (1 x 10(7) PFU/ml administered at 0.3, 0.5, and 1.0 ml per cohort). No grade III/IV adverse events were attributed to study medication. Replication-competent retrovirus was not detected in any of the 17 patients by polymerase chain reaction studies. Eight patients showed elevated anti-tumor antibody responses in comparison with baseline by ELISA. One of nine patients treated with a single course had an optimal response of stable disease, compared with eight of eight multiple-injected patients. Median survival of single-injected patients was 150 days, and patients who received multiple injections have still not achieved median survival duration, with four of eight still living (p = 0.0462, Wilcoxon; p = 0.0273, log rank). We conclude that intratumor injection of IFN-gamma is safe and well tolerated. Evidence of antitumor activity is suggested in patients with advanced malignancy that received multiple injections.

Cell Culture Processes for the Production of Viral Vectors for Gene Therapy Purposes

“…Therefore, the actual viral dose may be 10-1000 times greater (Braas et al 1996;Lyddiat and O'Sullivan 1998). It was subsequently shown empirically that titers >5 · 10 7 IP ml À1 of infusion product can efficiently obtain in vivo gene transfer in animal models of hemophilia, arthritis, cancer, chronic HBV infection, cystic fibrosis and other diseases (Ghivizzani et al 1997;Karavodin et al 1998;Sallberg et al 1998;Wang et al 1998;Nemunaitis et al 1999;Van den Driessche et al 1999). This still leaves a gap between the number of viral particles required and the number that can be produced.…”

Induction of melanoma-associated antigen systemic immunity upon intratumoral delivery of interferon-γ retroviral vector in melanoma patients

“…18 Briefly, human IFN-␥ cDNA was subcloned into an N2-based vector backbone derived from the Moloney murine leukemia virus to generate the proviral vector plasmid. The Moloney murine leukemia long terminal repeat controls the expression of the IFN-␥ gene, and an internal simian virus 40 promoter drives the expression of the neomycin-resistant selectable markers.…”

“…Individual clones were isolated and characterized for various characteristics as described previously. 18 Retroviral vector production was as described previously. 18,26 Briefly, a vial of IFN-␥ vector-producing cell line was thawed from a working cell bank and expanded in a culture flask.…”

“…18 Retroviral vector production was as described previously. 18,26 Briefly, a vial of IFN-␥ vector-producing cell line was thawed from a working cell bank and expanded in a culture flask. After several days in culture, the supernatant (total amount 200 L) was harvested daily for ϳ5 days.…”

“…8,9 In a phase I clinical trial involving a single injection of IFN-␥ retroviral vector every day for 5 days, no significant toxicity occurred and no replication-competent retrovirus was detected by polymerase chain reaction (PCR). 17,18 This initial study showed transgene expression, clinical safety, and suggestive clinical activity. The main purpose of the current study was to determine tolerability and evidence of antitumoral activity after multiple i.t.…”