Ziopharm Oncology, Inc. has received approval from the US Food and Drug Administration to initiate a Phase I/II trial with one of its two lead products, ZIO-101, a novel organic arsenic, in patients with advanced myeloma.

This announcement follows a similar approval for a Phase I/II trial for ZIO-201, a novel alkylator, in patients with advanced sarcoma. Patient treatment in both trials is expected to start in early 2006 at leading cancer centres in the US, Canada, and UK. Completion of enrolment is expected by the end of 2006, followed by pivotal trials beginning mid-2007.

According to the company release, the company believes ZIO-101 has the potential to treat patients with myeloma at significantly higher doses compared to arsenic trioxide, an inorganic arsenic currently approved to treat APL (acute promyelogenous leukaemia), which has also shown activity in myeloma. Currently in Phase I clinical trials, interim results on ZIO-101 were reported during a press conference at the AACR-NCI-EORTC International Conference in November 2005.

As announced, dosing of ZIO-101 was approximately 25 times higher (presently 35 times higher) than the approved dose of arsenic trioxide. The interim data reported evidence of meaningful benefit in one patient, and no significant toxicity. The Company believes a higher dose coupled with less toxicity will provide a wider therapeutic window and an incremental benefit, or treatment alternative, for myeloma patients, as newly approved agents continue to be associated with significant toxicities and/or drug resistance at therapeutic doses, stated the release.