US-based Threshold Pharmaceuticals has started a Phase II clinical trial of its investigational hypoxia-activated prodrug, TH-302, in combination with pemetrexed to treat patients with advanced non-squamous non-small cell lung cancer (NSCLC).
A total of 440 patients will be enrolled in the randomised, double-blind, placebo-controlled trial, which is designed to compare the combination of TH-302 and pemetrexed versus the combination of pemetrexed and placebo as second-line therapy in these patients.
In the trial, a TH-302 dose of 400mg/m² will be used in combination with full-dose pemetrexed.
The trial's primary endpoint is overall survival and its secondary endpoints include safety and assessment of anti-tumour activity as determined by progression-free survival and objective response rate.
Threshold chief executive officer Barry Selick said: "Independent studies have demonstrated the presence of hypoxia in tumours from patients with NSCLC.
"Early clinical research conducted by Threshold also supports further evaluation of TH-302 in combination with pemetrexed as a potential second-line treatment for patients with non-squamous NSCLC, many of whom still face a poor prognosis because of limited treatment options."
The company said that median progression-free survival was seven months and median overall survival was 14.9 months as demonstrated in a completed Phase I/II trial that assessed TH-302 in combination with full-dose pemetrexed in 18 patients with relapsed/refractory non-squamous NSCLC.
UCLA Hematology & Oncology director of clinical trials in thoracic oncology and principal investigator Jonathan Goldman said: "TH-302 is a hypoxia-activated prodrug that has shown encouraging anti-tumour activity across a wide range of cancers in investigational trials, and we are excited about evaluating TH-302 in combination with pemetrexed as potential second-line treatment for patients with non-squamous NSCLC."
TH-302 is currently being evaluated in two Phase III trials, with one in combination with doxorubicin versus doxorubicin alone in patients with soft tissue sarcoma, and the other in combination with gemcitabine versus gemcitabine and placebo in patients with advanced pancreatic cancer (MAESTRO).
The two trials are being carried out under special protocol agreements with the US Food and Drug Administration (FDA).
Both FDA and the European Commission (EC) have granted TH-302 orphan drug status for treatment of soft tissue sarcoma and pancreatic cancer.
Image: Micrograph of a squamous carcinoma, a type of non-small-cell lung carcinoma. Photo: courtesy of Nephron.