LAWRENCEVILLE, N.J., Jan. 27, 2014 /PRNewswire/ -- Celsion Corporation (NASDAQ: CLSN) today announced that the latest overall survival data from its post-hoc analysis of results from the Company's Phase III HEAT Study of ThermoDox®, Celsion's proprietary heat-activated liposomal encapsulation of doxorubicin in combination with radio frequency ablation (RFA), supports the continued clinical development of ThermoDox® in a prospective pivotal Phase III Study, subject to regulatory review and agreement. This analysis followed the announcement on January 31, 2013, that the HEAT Study did not meet its primary endpoint, progression-free survival (PFS). As provided for in the HEAT Study's Special Protocol Assessment (SPA) agreement with the U.S. Food and Drug Administration (FDA), 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 HEAT Study (3-5 cm and 5-7 cm) and represent a subgroup of 285 patients (41% of the patients in the HEAT Study). Updated OS data from this subgroup of patients is summarized below:
- In the patient subgroup treated in the ThermoDox® arm, whose RFA procedure lasted longer than 45 minutes (285 patients or 63% of single lesion patients) clinical results indicate a 55% improvement in overall survival, a Hazard Ratio of 0.64 (95% CI 0.41 – 1.00) and a P-value = 0.0495. Median overall survival for this subgroup has not yet been reached.
- In contrast, the patient subgroup treated with ThermoDox® whose RFA procedure lasted less than 45 minutes in duration (167 patients or 37% of single lesion patients) indicated a Hazard Ratio of 1.12 (95% CI 0.68 – 1.86) and a P-value = 0.66. Median overall survival for this subgroup has not yet been reached.
- The Hazard Ratios reported above warrants additional clinical development and should be viewed with caution since they are based on a retrospective analysis and the HEAT Study has not reached its median point for overall survival analysis. Celsion will continue to follow patients in the HEAT Study to the secondary endpoint, overall survival, and will update the subgroup analysis based on RFA heating duration.
"The HEAT Study post-hoc data is compelling. The combination of ThermoDox® and an optimized RFA treatment appears to have a significant improvement in overall survival in HCC patients," stated Dr. Nicholas Borys, Celsion's Chief Medical Officer. "While this conclusion is reached based on a post-hoc evaluation, it is nonetheless supported by the consistency of the data seen over a one year follow-up period, and by what is now a statistically significant outcome for overall survival. Our investigators are convinced that RFA can and should be optimized in future trials."
The HEAT Study and prior post-hoc analyses were presented at three medical conferences in 2013, including the World Conference on Interventional Oncology in May; the European Conference on Interventional Oncology in June and the International Liver Cancer Association Annual Conference in September. Presentations were made by some of the most highly recognized liver cancer researchers and key HEAT Study investigators. Quarterly overall survival data analyses have been conducted with the full support of these researchers and clinical investigators.