Around 68 patients with visible lesions or lesions accessible by injection are expcted to be enrolled in the multi-centre US study.
Mary Crowley Medical Research Center lead investigator and executive medical director John Nemunaitis said, "For breast cancer, the positive correlation of survival with immune response in the tumor elicited by non-immune treatments has only recently been elucidated, and this understanding hints at the potential for exciting new breakthroughs in this still underserved population."
First part of the two part study will assess the safety for Ad-RTS IL-12 and palifosfamide, alone or in combination while second part will assess the efficacy of the Ad-RTS IL-12 only arm and the combination arm.
Rate of progression-free survival at 16 weeks is the primary endpoint.
Secondary endpoints are objective response rate, duration of response and evaluation of pharmacodynamic tumour markers.
ZIOPHARM chief executive officer Jonathan Lewis said, "Building on preclinical work supporting a synergistic effect between Ad-RTS IL-12 and palifosfamide, and the clinical findings from our ongoing Phase 2 melanoma study, we believe the combination of Ad-RTS IL-12 and palifosfamide has the potential to be quite impactful in breast cancer."