NEW YORK, Nov 14, 2011 (BUSINESS WIRE) — ZIOPHARM Oncology, Inc. ZIOP +0.86% , a drug development company employing small molecule and synthetic biology approaches to cancer therapy, announced today promising clinical results from an ongoing multicenter Phase 1b, open-label, dose escalation study of intravenous (IV) palifosfamide (Zymafos(R) or ZIO-201) in combination with etoposide and carboplatin in patients with small cell lung cancer (SCLC) and other selected cancers. The data are being presented at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics, being held November 12-16, in San Francisco.

Palifosfamide is a novel DNA cross-linker in class with bendamustine, ifosfamide, and cyclophosphamide. The ongoing Phase 1b study was designed to assess the safety and efficacy of palifosfamide in combination with carboplatin and etoposide (PaCE) in SCLC and other cancers in which carboplatin plus etoposide is considered an appropriate therapeutic option. A previous randomized study evaluating the addition of ifosfamide to cisplatin and etoposide in SCLC demonstrated improved survival, but with a disabling increase in toxicity with the combination. The rationale for substituting palifosfamide for ifosfamide in this three-drug regimen includes the abrogation of ifosfamide-metabolite related toxicities, an ability to increase the dose delivered over time, and avoiding resistance mediated by aldehyde dehydrogenase (ALDH) overexpression. ALDH overexpression is associated with cancer cell stem-like potential in several tumor types and is thought to confer resistance to ifosfamide and cyclophosphamide.