Threshold reports initiation of TH-302 and bevacizumab clinical trial for astrocytoma

Threshold Pharmaceuticals, Inc. (Nasdaq:THLD), today announced that the University of Texas at San Antonio initiated a clinical trial of TH-302 in combination with bevacizumab in patients with recurrent high grade astrocytoma including glioblastoma. Bevacizumab, marketed by Roche under the brand name Avastin^®, is a recombinant humanized monoclonal antibody that affects tumor vasculature which among its several approved indications is used to treat glioblastoma in patients whose cancer has progressed after prior treatment. Published studies have shown that treatment with Avastin increases the extent of hypoxia within the tumor. TH-302 is a novel small molecule hypoxia-targeted prodrug that is selectively activated by the low oxygen conditions believed to be induced in tumors by antiangiogenic therapies such as Avastin^®. With data from over 500 patients to date, TH-302 is currently being evaluated in a controlled Phase 2 clinical trial in patients with advanced pancreatic cancer, with a planned pivotal Phase 3 clinical trial in patients with soft tissue sarcoma expected to commence in the 3^rd quarter of this year.

“While some success has been seen with drugs that target the tumor blood supply, patients ultimately relapse and there is increasing evidence that tumor hypoxia may be contributing to that treatment failure”

"We are excited to evaluate TH-302 for the treatment of high grade brain tumors and to further explore the role of tumor hypoxia as a potential target in the treatment of this disease," said Andrew Brenner, M.D., Ph.D., a neuro-oncologist at the Cancer Therapy & Research Center at The University of Texas Health Science Center at San Antonio and principal investigator for the trial. "While some success has been seen with drugs that target the tumor blood supply, patients ultimately relapse and there is increasing evidence that tumor hypoxia may be contributing to that treatment failure," Dr. Brenner said. "In addition to establishing the safety and preliminary efficacy of TH-302 in combination with bevacizumab, this will be the first clinical study with TH-302 that will directly measure tumor hypoxia in solid tumors and attempt to correlate that with response."