ZIOPHARM Reports Positive Interim Results From Phase 1/2 Study Of Ad-RTS-IL-12

(RTTNews) - ZIOPHARM Oncology, Inc. (ZIOP) announced presentation of interim results from its ongoing Phase 1/2 study of Ad-RTS-IL-12, a DNA-based therapeutic candidate that is being evaluated with the oral activator, veledimex, in patients with advanced melanoma.

The results from this multicenter study were presented at Melanoma Bridge 2013 Conference at the session "Best Abstracts on News in Immunotherapy".

In this study, 21 patients with unresectable, recurrent stage III/IV melanoma have been treated with intratumoral injections of Ad-RTS-IL-12 and the oral activator veledimex.

The company noted that, to date, expression of IL-12 mRNA in study subjects' tumors was determined to be very high and tightly controlled by veledimex dose with expression ranging from a median increase of approximately 1,000 times with an oral dose of 100 mg to approximately 100,000 times with an oral dose of 160 mg.

In addition, upon stopping veledimex dosing, expression of the IL-12 mRNA returned to baseline levels, demonstrating the "on" and "off" control of Intrexon Corp.'s (XON) RheoSwitch Therapeutic System platform. In this dose range, results to date show that Ad-RTS-IL-12 + veledimex has potent biologic activity, as measured by on-mechanism and on-target toxicity and response in injected and non-injected lesions. In addition, increased tumor infiltrating lymphocytes were observed in the tumor microenvironment at these doses, suggesting multiple favorable biologic effects of IL-12 expression.

The company said 11 of 16 evaluable patients have demonstrated a response of stable disease or better on a per lesion basis.