ZIOPHARM ANNOUNCES RESULTS FROM MULTIPLE MYELOMA STUDY

Ziopharm Oncology has announced findings from a Phase I study of ZIO-101, a proprietary organic arsenic, showing that 43 percent of relapsing, progressing multiple myeloma patients experienced stable disease and that the drug was well tolerated in all 14 patients in the study group. There was no clinically significant bone marrow suppression in patients with either prior or no prior transplant. The patients in the study group had failed a median of eight prior treatments. These data suggest that ZIO-101 may be active in myeloma, and may also be useful in patients who suffer a disease relapse after having a bone marrow transplant.

In the study, six out of 14 patients achieved at least stable disease. Two patients have had stable disease for longer than six months, and one, who had a prior transplant, has had stable disease for five months. There was no clinically relevant QT prolongation and, unlike with many other drugs used to treat multiple myeloma, no clinically relevant bone marrow suppression in the patient group, according to the company.

ZIO-101 induces cell cycle arrest and cell death by targeting several cellular pathways essential for cell survival. Exposure to ZIO-101 has a direct as well as indirect effect on mitochondrial functions, resulting in depletion of energy supply to the cell and induction of apoptosis (programmed cell death). Increase in intra-cellular reactive oxygen species enhances this effect on mitochondrial functions and consequently the activation of the signal transduction pathway leading to apoptosis. In addition, ZIO-101 interrupts the cell cycle at the G2/M phase of tumor cells, inducing cell death through this pathway as well.