Celsion’s ThermoDox in combination treatment improves survival by more than 50%

US cancer drug developer Celsion Corp (Nasdaq: CLSN) says that the latest overall survival data from its Phase III HEAT study of ThermoDox, a proprietary heat-activated liposomal encapsulation of doxorubicin, in combination with radio frequency ablation (RFA) in liver cancer supports its continued clinical development. Shares of the company dropped 2.2% to $3.75 in mid-morning trading on the news.

This analysis followed the announcement on January 31, 2013, that the HEAT Study did not meet its primary endpoint of progression-free survival (PFS). As provided for in the HEAT study's Special Protocol Assessment (SPA) agreement with the US Food and Drug Administration, the company continues to follow patients for overall survival, the secondary endpoint of the study. Data from four quarterly reviews of overall survival have been evaluated since the announcement of top line PFS data.

Data from the updated HEAT study analysis suggests that ThermoDox may significantly improve overall survival, compared to control, in patients whose lesions undergo RFA treatment for 45 minutes or more. These findings apply to patients with single HCC lesions (64.4% of the HEAT Study population) from both size cohorts of the study and represent a subgroup of 285 patients (41% of the patients in the HEAT Study).