REDWOOD CITY, Calif., April 20, 2010 (GLOBE NEWSWIRE) -- Threshold Pharmaceuticals, Inc. (Nasdaq:THLD), today announced multiple preclinical presentations on its clinical stage hypoxia-activated prodrug, TH-302, at the American Association for Cancer Research (AACR) Annual Meeting, being held April 17 to 21, 2010, in Washington, D.C.
"These are very exciting preclinical results which extend our understanding of the mechanism of action and antitumor activity of TH-302," said Charles Hart, Ph.D., Threshold's vice president of biology. "Our translational observations provide further support that TH-302 is selectively targeting tumor hypoxia and continue to inform the design of our clinical programs."
Poster 5388, J.D.Sun et al., (Sequence- and Regimen-Dependent Combination Therapy with the Hypoxia-Activated Prodrug TH-302 and Doxorubicin in a Preclinical Sarcoma Xenograft Model) demonstrates that, consistent with previous studies, combination therapy of TH-302 and conventional chemotherapeutics shows sequence- and regimen-dependent antitumor activity and toxicity profiles.
Poster 4465, J.D. Sun et al., (In Vivo Antitumor Characterization of the Hypoxia-Activated Prodrug TH-302 in a Preclinical SCLC Xenograft Model) demonstrates an antitumor effect of TH-302 through cytotoxic activity on the hypoxic compartment in the tumor. The results support an in vivo tumor hypoxia targeting mechanism of TH-302.
Poster 2263, F.Meng et al., (NADPH-Cytochrome P450 Reductase Reduction of TH-302, a Hypoxia-Activated Prodrug) studied the difference between TH-302 and pimonidazole in the rate of subsequent reaction after formation of the radical anion. The results support the hypothesis that TH-302 can eliminate at the radical anion stage and release its cytotoxic warhead in a hypoxia-dependent manner.
A copy of the posters presented at AACR may be obtained by calling the Company.
About Threshold Pharmaceuticals
Threshold is a biotechnology company focused on the discovery and development of drugs targeting Tumor Hypoxia, the low oxygen condition found in microenvironments of most solid tumors. This approach offers broad potential to treat most solid tumors. By selectively targeting tumor cells, we are building a pipeline of drugs that hold promise to be more effective and less toxic to healthy tissues than conventional anticancer drugs. For additional information, please visit our website (www.thresholdpharm.com).
Forward-Looking Statements
Except for statements of historical fact, the statements in this press release are forward-looking statements, including statements regarding the mechanism of action and anti-tumor activity of TH-302, pre-clinical study results and plans, and potential therapeutic uses and benefits of TH-302. These statements involve risks and uncertainties that can cause actual results to differ materially from those in such forward-looking statements. Potential risks and uncertainties include, but are not limited to, Threshold's ability to commence its anticipated clinical trials, the time and expense required to conduct such clinical trials and analyze data, the possibility that results from these trials will not be confirmed in subsequent trials, potential adverse side effects, issues arising in the regulatory or manufacturing process and the results of such clinical trials (including product safety issues and efficacy results). Further information regarding these and other risks is included under the heading "Risk Factors" in Threshold's Annual Report on Form 10-K, which was filed with the Securities Exchange Commission on March 8, 2010 and is available from the SEC's website (www.sec.gov) and on our website (www.thresholdpharm.com) under the heading "Investors." We do not intend to update any forward-looking statement made in this news release.