MB07133 is a novel HepDirect prodrug of cytarabine monophosphate (araCMP) designed to produce the oncolytically active form cytarabine triphosphate (araCTP) in the liver tumor, where it acts to inhibit cell proliferation and induce apoptosis.
Preliminary results from a Phase I/II clinical trial for MB07133, which was completed in the second quarter of this year, were presented at the annual meeting of the American Association for Cancer Research (AACR) in April 2007.
This first-dose escalation trial showed that at doses up to 2400mg/m2/day, administered as a seven-day continuous intravenous infusion, the drug was well tolerated in patients with unresectable hepatocellular carcinoma (HCC).
No clinically important dose-limiting toxicities associated with the therapy and few treatment-related hepatic adverse events were observed, Metabasis said.
Additionally, the trial revealed encouraging signs of drug activity evidenced by tumor shrinkage and disease stabilization. Intra-hepatic tumor reduction was observed in seven patients (25% of those studied), and increased median overall survival was seen in these patients, relative to the other patients in the study.
“There is a critical need for effective therapies for primary liver cancer,” commented Dr Paul Laikind, president and CEO. “Patients often die within months of diagnosis and at this time, they face this disease without any FDA-approved drug therapy or standard of care. The granting of orphan drug designation should enhance the value of MB07133 as a novel therapy for this fatal disease should it be approved.”