Threshold Pharmaceuticals Receives Two U.S. Patents for Tarloxotinib Bromide

Threshold Pharmaceuticals, Inc.

today announced that the U.S. Patent and Trademark Office (USPTO) has issued the first two U.S. patents protecting tarloxotinib bromide*, or "tarloxotinib," the Company's proprietary hypoxia-activated, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor exclusively licensed from the University of Auckland, New Zealand. The first patent, U.S. Patent No. 9,073,916, generically covers a structural class of EGFR tyrosine kinase inhibitor prodrugs, including tarloxotinib, and pharmaceutical compositions containing this structural class of prodrugs. The second patent, U.S. Patent No. 9,101,632, specifically covers the compound tarloxotinib and pharmaceutical compositions containing it. "These two patents provide fundamental intellectual property protection for tarloxotinib, which is the subject of two ongoing Phase 2 clinical trials for the treatment of patients with mutant EGFR-positive non-small cell lung cancer and patients with squamous cell cancers of the head and neck or skin," said Barry Selick, Ph.D., Chief Executive Officer of Threshold. "Currently, treatment with EGFR inhibitors has limited efficacy because side effects can prevent effective doses from being achieved. We believe that more effective dosing may be achievable with tarloxotinib, which is designed to release an irreversible EGFR tyrosine kinase inhibitor selectively under hypoxic conditions commonly found within solid tumors. Tumor-selective activation of tarloxotinib may allow for greater inhibition of EGFR signaling within the tumor while limiting systemic side effects, potentially leading to better outcomes for patients with EGFR-dependent cancers." *Tarloxotinib bromide is the proposed International Nonproprietary Name.