SOUTH SAN FRANCISCO, CA--(Marketwired - Apr 3, 2014) - Threshold Pharmaceuticals, Inc. (NASDAQ: THLD) today announced that results of two new preclinical studies evaluating novel combinations of TH-302, its investigational hypoxia-targeted drug, with immunotherapy, antiangiogenic therapy, and radiotherapy for the potential treatment of cancer will be highlighted in poster presentations at the American Association for Cancer Research (AACR) Annual Meeting 2014 taking place April 5 - 9, in San Diego, California.

"The rapidly evolving landscape in discovery and development of new cancer therapeutics includes exploring novel combinations of different treatment modalities such as targeted therapies, immunotherapy, radiotherapy and chemotherapeutic agents," said Charles Hart, Ph.D., Vice President of Biology at Threshold. "We believe that targeting the hypoxic tumor microenvironment, which harbors cells that are resistant to conventional therapies and prone to metastasize, may be an important component of new combination approaches to treating cancer. In Phase 1 and 2 clinical trials, TH-302 has demonstrated encouraging anti-tumor activity when used as a single agent or as part of combination regimens. We believe that data from the preclinical studies, to be presented at AACR, warrant further evaluation of additional potential therapeutic combinations using TH-302." 

Poster presentation details:

Abstract #629 (Poster #4): Combination hypoxia-specific chemotherapy and immunotherapy of prostate cancer;
1:00 PM - 5:00 PM Pacific Time on Sunday, April 6, 2014, in Hall A-E, Poster Section 27.

Abstract #5447 (Poster #23): Targeting vascular endothelial growth factor A and tumor hypoxia combined with radiation eradicates sarcomas through destruction of tumor vasculature and thwarting of the hypoxic response;
8:00 AM - 12:00 PM Pacific Time on Wednesday, April 9, 2014, in Hall A-E, Poster Section 30.

About TH-302
TH-302 is an investigational hypoxia-targeted drug that is designed to be activated under tumor hypoxic conditions, a hallmark of many cancers. Areas of low oxygen levels (hypoxia) in solid tumors are due to insufficient blood supply as a result of aberrant vasculature. Similarly, the bone marrow of patients with hematological malignancies has also been shown, in some cases, to be severely hypoxic.

TH-302 is currently under evaluation in two Phase 3 trials: one in combination with doxorubicin versus doxorubicin alone in patients with soft tissue sarcoma, and the other in combination with gemcitabine versus gemcitabine and placebo in patients with advanced pancreatic cancer (MAESTRO). Both Phase 3 trials are being conducted under Special Protocol Agreements with the U.S. Food and Drug Administration (FDA). The FDA and the European Commission have granted TH-302 Orphan Drug Designation for the treatment of soft tissue sarcoma and pancreatic cancer. TH-302 is also being investigated in hematological malignancies and in combination with other therapies in a variety of solid tumors.

Threshold has a global license and co-development agreement for TH-302 with Merck KGaA, Darmstadt, Germany, which includes an option for Threshold to co-commercialize in the U.S.

About Threshold Pharmaceuticals
Threshold Pharmaceuticals, Inc. 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 as well as the bone marrows of some hematologic malignancies. This approach offers broad potential to treat a variety of cancers. 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 potential therapeutic uses and benefits of TH-302, including TH-302's potential to be a component of new combination approaches to treating cancer, and statements regarding the TH-302 clinical development program, including conduct of ongoing clinical trials and the potential development of new therapeutic combinations using 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: the ability of Threshold and Merck KGaA, Darmstadt, Germany, to enroll or complete TH-302 clinical trials; the time and expense required to conduct such clinical trials and analyze data; issues arising in the regulatory or manufacturing process and the results of such clinical trials (including product safety issues and efficacy results); the risk that preclinical studies in animal models of disease may not accurately predict the result of human clinical trials of TH-302; Threshold's and Merck KGaA's (Darmstadt, Germany) dependence on single source suppliers, including the risk that these single source suppliers may be unable to meet clinical supply demands for TH-302 which could significantly delay the development of TH-302; risks related to Threshold's dependence on its collaborative relationship with Merck KGaA, Darmstadt, Germany, including its dependence on decisions by Merck KGaA, Darmstadt, Germany regarding the amount and timing of resource expenditures for the development of TH-302; and Threshold's need for and the availability of resources to develop TH-302 and to support Threshold's operations. Further information regarding these and other risks is included under the heading "Risk Factors" in Threshold's Annual Report on Form 10-K, which has been filed with the Securities and Exchange Commission on March 6, 2014 and is available from the SEC's website (www.sec.gov) and on our website (www.thresholdpharm.com) under the heading "Investors." We undertake no duty to update any forward-looking statement made in this news release.