A Phase I Study of the Naturally Occurring Bioactive, Opioid Growth Factor, in Patients with Unresectable
Eric T Kimchi1, Jussuf T Kaifi2, Yixing Jiang3
1Department of Surgery, University of Connecticut, Farmington, Connecticut, USA.
Abstract:
Hepatocellular cancer (HCC), one of the world's most deadly tumors, and its incidence in the US continues to rise. Surgical resection/transplantation offers the only hope for cure; however, many patients are not candidates and have limited therapeutic options. Opioid growth factor (OGF) is a naturally occurring bioactive endogenous pentapeptide that inhibits growth of human HCC cell lines in vitro by a receptor-mediated mechanism and inhibits progression of tumors in nude mice. Based on these preclinical studies, we conducted a phase I clinical trial with dose escalation (standard 3 + 3 protocol) of OGF to determine the maximum tolerated dose in HCC patients with concomitant liver disease (NCT00706576). Fifteen doses were administered to 14 patients with a maximum 300 µg/kg dose. No Grade 3 toxicities were encountered in the study group. This dose exceeds the maximum tolerated dose reached in our previous phase I pancreatic cancer trial. We conclude that OGF can be safely administered to patients with HCC and concomitant liver disease without significant toxicities up to a dose of 300 µg/kg. The result of this trial provides data on toxicity and the pharmacokinetics of OGF in patients with HCC and liver disease and lays the groundwork for additional studies.
