ZIO-101, a novel organic arsenic, has demonstrated safety at doses approximately 25 times higher than the currently approved dose for arsenic trioxide, an inorganic arsenic currently approved for acute promyelocytic leukemia.
One patient with metastatic renal cell cancer responded with complete resolution of brain metastasis and overall stable disease.
The phase I clinical trial was designed to determine the maximum tolerated dose of ZIO-101. The dose escalation study has completed dose cohort three, at which a significantly higher dose is administered as compared to the approved dose for arsenic trioxide.
“At a dosing level already much higher than arsenic trioxide, with provocative hints of a clinical signal, these preliminary phase I data suggest we are on the right track with what may be a new, less toxic therapy in treating patients with cancer,” said Dr Luis Camacho of The University of Texas M D Anderson Cancer Center.
ZIO-101 is the lead product candidate from a “family” of compounds licensed from The University of Texas M D Anderson Cancer Center and Texas A&M University. A second organic arsenic from the same licensing arrangement, ZIO-102, is the subject of further preclinical study.
A phase I/II trial and a phase II trial for ZIO-101 in advanced myeloma are in the advanced planning stage and will likely be followed with exploratory phase II trials in other cancers. A pivotal registration trial is expected to begin in the first half of 2007.