WALTHAM, Mass., April 22, 2009 (GLOBE NEWSWIRE) -- OXiGENE, Inc. (Nasdaq:OXGN) (XSSE:OXGN), a clinical-stage, biopharmaceutical company developing novel therapeutics to treat cancer and eye diseases, reported data showing that OXi4503 has pronounced antitumor activity when administered as a single agent or in combination with chemotherapy in acute myelogenous leukemia (AML) xenograft models. In the studies, NOD-SCID mice bearing established HL60 xenografts were treated with a series of doses and regimens of either OXi4503 or fosbretabulin administered either as single agents, or combined with araC (standard AML chemotherapy) and evaluated for signs of activity. Results showed that the antitumor activity of OXi4503 against HL60 xenografts is superior to that observed for fosbretabulin, and that HL60 AML xenografts are sensitive to OXi4503 administered as a single agent. In addition, the combination of OXi4503 with araC increased antitumor activity with no apparent increase in toxicity.
"These results add to previously published data obtained with fosbretabulin which demonstrate in an animal study significant single-agent anti-leukemic action of OXiGENE's VDAs. We believe, based on the data available to date, that the anti-leukemic action is mediated through multiple mechanisms, including direct cytotoxicity and vascular disruption. More importantly, in the case of orthotopic leukemia models, the compound's activity may be related to release of treatment-resistant leukemic cells from stromal niches via disruption of VLA4-VCAM1 interactions," commented David Chaplin, Ph.D., Chief Scientific Officer at OXiGENE. "We believe that these results are particularly exciting as they demonstrate that OXi4503 may have potential as a single-agent therapy for certain leukemias."
OXiGENE anticipates that further corroborative OXi4503 preclinical data in AML obtained by OXiGENE's collaborators will be presented at a future scientific meeting. The company is currently assessing its options for clinically evaluating OXi4503 as a potential treatment for patients with AML.
About OXi4503
OXi4503 (combretastatin A1 di-phosphate / CA1P) is a dual-mechanism vascular disrupting agent (VDA) that is being developed in clinical studies for the treatment of solid tumors. Like its structural analog, ZYBRESTAT(TM) (fosbretabulin / CA4P), OXi4503 has been observed to block and destroy tumor vasculature, resulting in -- more -- extensive tumor cell death and necrosis. In addition, preclinical data indicate that OXi4503 is metabolized by oxidative enzymes (e.g., tyrosinase and peroxidases), which are elevated in many solid tumors and tumor white blood cell infiltrates, to an orthoquinone chemical species that has direct cytotoxic effects on tumor cells. Preclinical studies have shown that OXi4503 has (i) single-agent activity against a range of xenograft tumor models; and (ii) synergistic or additive effects when incorporated in various combination regimens with chemotherapy, molecularly-targeted therapies (including tumor-angiogenesis inhibitors), and radiation therapy. OXi4503 is currently being evaluated as a monotherapy in a Phase 1 dose-escalation study in patients with advanced solid tumors. OXiGENE is developing OXi4503 under the strategic drug development partnership it established with Symphony Capital in October 2008.
About OXiGENE
OXiGENE is a clinical-stage biopharmaceutical company developing novel therapeutics to treat cancer and eye diseases. The company's major focus is developing VDAs that selectively disrupt abnormal blood vessels associated with solid tumor progression and visual impairment. OXiGENE is dedicated to leveraging its intellectual property and therapeutic development expertise to bring life-extending and -enhancing medicines to patients.
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Safe Harbor Statement
This news release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Any or all of the forward-looking statements in this press release may turn out to be wrong. Forward-looking statements can be affected by inaccurate assumptions OXiGENE might make or by known or unknown risks and uncertainties, including, but not limited to, mechanisms of anti-leukemic action of OXi4503, the potential of OXi4503 as a single-agent therapy for certain leukemias and publication of further corroborative OXi4503 preclinical data in AML obtained by OXiGENE's collaborators. Additional information concerning factors that could cause actual results to materially differ from those in the forward-looking statements is contained in OXiGENE's reports to the Securities and Exchange Commission, including OXiGENE's reports on Form 10-K, 10-Q and 8-K. However, OXiGENE undertakes no obligation to publicly update forward-looking statements, whether because of new information, future events or otherwise. Please refer to our Annual Report on Form 10-K for the fiscal year ended December 31, 2008.