ZIOPHARM Presents Positive Darinaparsin Clinical Data At ASCO's Prestigious Clinical Science Symposium

Main Category: Cancer / Oncology
Also Included In: Clinical Trials / Drug Trials
Article Date: 02 Jun 2009 - 8:00 PDT

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ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) announced today that it presented positive data from both Phase II intravenous (IV) and Phase I oral studies of darinaparsin (ZinaparTM or ZIO-101), the novel organic arsenic molecule, as part of the prestigious Clinical Cancer Symposia at the 45th Annual American Society of Clinical Oncology (ASCO) meeting held in Orlando, FL, May 29th to June 2nd.

The study results were presented at the Clinical Science Symposium, New Agents for Lymphoma, by Izidore S. Lossos, M.D, Chief of the Lymphoma Program, and Professor of Medicine at the University of Miami Miller School Of Medicine. Darinaparsin was one of three new drugs selected at this high profile ASCO session.

"This drug is active in highly-refractory lymphoma patients and well tolerated," commented Dr. Lossos, lead investigator for the Phase II trial. "Interestingly a lot of patients I and others have treated with this drug report feeling the best they have felt since first getting lymphoma, having been on many different treatments. The oral data are also promising and darinaparsin could well be effective in treating other cancers as well."

The Phase II intravenous (IV) study is fully enrolled with 29 heavily pretreated lymphoma patients. Of 19 evaluable patients, initial findings are 7 objective responses, for an overall response rate of 37 percent, with 3 complete responses (CRs) and 4 partial responses (PRs). Four additional patients had prolonged stable disease (SD). There are 5 peripheral T-cell lymphoma (PTCL) patients included in the 19 patients and in this group there were 3 objective responses, for an overall response rate of 60 percent, of which there were 2 CRs and 1 PR. Of the 4 patients with stable disease, 1 patient had PTCL. Darinaparsin was very well tolerated with neutropenic fever as a severe adverse event in 1 patient.

On the advice of multiple experts, the Company intends, on complete review of the final data, to open dialogue with the U.S. Food and Drug Administration with a view of entering into a formal registration trial, likely for peripheral T-cell lymphoma where, even with other agents under evaluation, there remains a very high unmet medical need.

The two Phase I oral dose escalation studies included patients with all types of cancers. Darinaparsin was dosed with various schedules. The study included 36 patients. The study has not yet reached MTD. Of 27 evaluable patients, 1 had a partial response (head and neck cancer) and 15 had prolonged stable disease, including head and neck, lymphoma, colon, and pancreatic cancers. Oral darinaparsin was well tolerated with atrial fibrillation, congestive heart failure and dyspnea as severe adverse events.

Treatment with darinaparsin has not evidenced any QT prolongation in either the IV or oral studies. QT prolongation has been problematic with inorganic arsenic and is a "black box" side effect warning in the labeling. The Company continues dialogue regarding partnering and other initiatives regarding the further clinical development of darinaparsin.

To view the presentation please visit here.

Source
ZIOPHARM Oncology, Inc.