Phase III Results With Zeneca's Tomudex

Zeneca has presented the results of a Phase III study of its specific thymidylate synthase inhibitor, Tomudex (ZD1694), at the International Congress of Chemotherapy in Montreal, Canada. The data suggest that Tomudex is a real advance over a standard chemotherapy regimen, consisting of 5-fluorouracil and leucovorin, in the treatment of patients with advanced colorectal cancer.

The study involved 439 patients with advanced colorectal cancer who were recruited over a seven-month period - a far more rapid enrollment rate than was anticipated, according to David Cunningham of the Royal Marsden Hospital in the UK, the principal clinical investigator for the study. The patients were randomized to receive either Tomudex by single injection (3.0mg/m2) every three weeks, or 5-FU plus leucovorin (425mg/m2 and 20mg/m2 respectively) for five days, every four weeks.

In terms of achieving an objective tumor response to therapy, there was a slight advantage in favor of Tomudex; 20% of patients who received this drug achieved a 50% reduction or greater in tumor volume, compared to 13% of patients on standard therapy. The percentage of patients whose tumors decreased in volume by 40%-50% was 9% in the Tomudex, and 3% in the combination group.