Merck Serono, a division of Merck, has commenced its Phase III MAESTRO study designed to assess the efficacy and safety profile of TH-302 in combination with gemcitabine in pancreatic adenocarcinoma patients.
The investigational hypoxia-targeted drug, TH-302, is designed to be activated under severe tumour hypoxic conditions caused due to insufficient blood supply resulting from aberrant vasculature.
Commencement of the study has triggered a $30m milestone payment to Threshold Pharmaceuticals from Merck under a license and co-development agreement signed between the two companies.
Threshold chief executive officer Dr Barry Selick said the commencement of the Phase III MAESTRO study has advanced the development of TH-302 to treat cancer patients.
"This marks the second Phase III study of TH-302 in addition to the ongoing Phase III pivotal trial in patients with soft tissue sarcoma," Selick said.
"In addition, we continue to explore the potential breadth and activity of TH-302 against a variety of solid tumours and haematological malignancies in multiple ongoing earlier stage clinical trials."
The randomised, placebo-controlled study of TH-302 plus gemcitabine will be compared with placebo plus gemcitabine in around 660 patients with previously untreated, locally advanced unresectable or metastatic pancreatic adenocarcinoma.
The primary efficacy endpoint of the study, which is being conducted under a special protocol assessment with the FDA, is overall survival.
Secondary endpoints are efficacy measured by progression-free survival, overall response rate and disease control rate, as well as assessments of safety and tolerability, pharmacokinetics and biomarkers.