SOUTH SAN FRANCISCO, CA--(Marketwire - Apr 25, 2012) - Threshold Pharmaceuticals, Inc. (NASDAQ: [ THLD ]) today announced the appointment of Robert Simon as Senior Vice President of Regulatory Affairs. Mr. Simon will oversee Threshold's regulatory activities related to the development of TH-302, a clinical stage hypoxia-targeted cancer therapeutic currently being evaluated in a variety of cancers. Six clinical trials of TH-302 are currently enrolling, including a Phase 3 trial in soft tissue sarcoma, and others are either pending or under consideration with partner, Merck KGaA across numerous oncology indications. Mr. Simon brings more than 28 years of drug development and regulatory affairs experience, particularly as a liaison with the US Food and Drug Administration (FDA) and international health authorities on new drug registrations, the initiation of clinical trials, and in the area of chemistry, manufacturing and controls (CMC).

"Bob has played key roles in the successful registration of more than a dozen new drug applications worldwide, including the established oncology drugs, Tarceva and Taxol," said Tillman Pearce, MD, Chief Medical Officer of Threshold. "His wealth of experience in the regulatory affairs arena will be especially valuable to us as we and Merck determine next steps following our successful Phase 2 trial in pancreatic cancer, look ahead to the completion of our Phase 3 pivotal trial in soft tissue sarcoma, and continue to move other studies forward in various oncology indications."

Before joining Threshold, Mr. Simon spent nearly 10 years at OSI Pharmaceuticals, initially as Vice President of Global Regulatory Affairs and CMC for oncology but more recently as an Executive Vice President in roles relating to pharmaceutical development, manufacturing and technical operations. Prior to OSI, he was Vice President of Global Regulatory Affairs for Gilead, covering oncology and anti-viral products, and before that, served at Bristol-Myers Squibb for more than 13 years in global regulatory affairs positions. With a degree in chemistry, Mr. Simon held chemistry and regulatory-related positions at Syntex and SRI International (formerly Stanford Research Institute) early in his career.

"I am looking forward to working with the Threshold team in developing the first hypoxia-targeted cancer drug, TH-302," said Bob Simon. "Cancer is an unforgiving disease that often recurs with a vengeance. TH-302 provides, for the first time, the promise of a drug that targets the hypoxic cells that are believed to underlie metastasis and treatment failure and which are little affected by available therapies. Because of TH-302's unique mode of action, it may well be someday the drug of choice to combine with other cancer therapy in a one-two knockout punch approach to managing this dreadful disease."

About TH-302

TH-302 is a hypoxia-targeted drug that is thought to be activated under tumor hypoxic conditions, a hallmark of many cancer indications. Areas of low oxygen levels (hypoxia) within tissues are common in many solid tumors due to insufficient blood vessel growth. Similarly, the bone marrow of patients with hematological malignancies has also been shown, in some cases, to be extremely hypoxic.

TH-302 has been investigated in over 600 patients in Phase 1/2 clinical trials to date in a broad spectrum of tumor types, both as a monotherapy and in combination with chemotherapy treatments and other targeted cancer drugs. Threshold has several additional ongoing clinical trials, the most advanced of which is a Phase 3 pivotal study evaluating TH-302 in combination with doxorubicin versus doxorubicin alone in patients with soft tissue sarcoma. In February 2012, Threshold signed a global agreement with Merck KGaA, Darmstadt, Germany, to co-develop and commercialize TH-302.

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 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, Threshold is 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 [ 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 TH-302's potential ability to treat cancers, planned clinical trials, 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 enroll or complete its anticipated clinical trials, the time and expense required to conduct such clinical trials and analyze data, whether such trials confirm results from earlier trials and preclinical studies, potential side effects associated with TH-302, and 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 has been filed with the Securities and Exchange Commission on March 15, 2012 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.