Ziopharm said that the preclinical work was designed to study darinaparsin’s cytotoxic and radiosensitizing effects against different solid tumor cell lines under both normoxic (NO) and hypoxic (HO) conditions.
In these studies, hormone independent prostate cancer, pancreatic cancer, cervical cancer, and glioblastoma cell lines were treated with darinaparsin at concentrations ranging from 0.01 to 10 uM under either NO or HO conditions and irradiated with doses of 0 – 5 Gy.
Results showed that darinaparsin is a potent cytotoxin under both NO and HO conditions and under HO when cells are resistant to radiation.
Significant radiation enhancement was also observed in clonogenic assays under HO at clinically relevant doses, raising the potential for synergistic and dose-sparing radiation therapy.
Stanford University School of Medicine Advising Dean Susan Knox said that Darinaparsin’s multiple mechanisms of action and potency provide for cytotoxicity and radiosensitization in a variety of tumor cell lines and environments.
"This activity suggests a broad potential applicability for Darinaparsin in the treatment of chemo- and radio-resistant solid tumors, with near term translational potential," Knox said.