"These results suggest that darinaparsin has the potential to sensitize relatively radioresistant tumors without affecting normal tissues," commented senior author, Susan J. Knox. "They further suggest that darinaparsin may increase the therapeutic index of radiation therapy and, as was shown with our first study, have near-term translational potential."

A second study, titled "Darinaparsin is an anti-solid tumor cytotoxin in vivo," again evaluated prostate and pancreatic tumor models treated with darinaparsin (100 mg/kg) or saline (control). In both the prostate and pancreatic tumor models, darinaparsin significantly inhibited tumor growth (p < 0.0001), with the average tumor volume doubling time increasing from 3.95 days to 11.8 days in the prostate tumor model, and 3.83 days to 6.82 days in the pancreatic tumor model. Importantly, no significant systemic toxicities were exhibited at studied dose, as assessed by organ histology and blood biochemistry.

Dr. Knox remarked: "Darinaparsin was found to have significant cytotoxic activity in these two well-established solid tumor models, without apparent systemic toxicity. With darinaparsin currently in clinical development, these findings may have near-term translational potential."

Source: ZIOPHARM Oncology, Inc.