Threshold Pharmaceuticals in the US has failed at getting its hypoxia prodrug evofosfamide through phase III trials for two types of cancer, and as a result has lost Merck‘s partnership on the program.
Evofosfamide (TH-302) is an investigational hypoxia-activated prodrug discovered by Threshold Pharmaceuticals in Pennsylvania (US). The prodrug is activated only at very low levels of oxygen (hypoxia). Such levels are common in human solid tumors, a phenomenon known as tumor hypoxia, which is a novel therapeutic approach that may be less likely to produce broad systemic toxicity seen with untargeted cytotoxic chemotherapies.
TH-302 has been evaluated for first-line treatment of advanced pancreatic adenocarcinoma and advanced soft tissue sarcoma. However, unfortunately Merck (aka EMD in the US) recently announced that it is not planning to file for approval of evofosfamide following the latest phase III trial results which failed to achieve primary endpoint (overall survival), as reported by Threshold.
The CEO of Threshold, Barry Selick, expressed the ‘