NEWS ~~~~ CLSN Duration of RFA Procedure Cor

NEWS ~~~~ CLSN Duration of RFA Procedure Correlates with an Overall Survival Benefit

LAWRENCEVILLE, N.J., May 17, 2013 /PRNewswire/ -- Celsion Corporation (CLSN) announced today that Professor Riccardo Lencioni, MD, FSIR, EBIR, 2013 WCIO Program Chairman and the Director of the Division of Diagnostic Imaging and Intervention at Pisa University School of Medicine in Italy and Lead European Principal Investigator for the HEAT Study and Professor Ronnie T.P. Poon, MD, MS, PhD, FRCS(Edin), FACS, Professor of Surgery at the University of Hong Kong and Lead Asia Pacific Principal Investigator for the HEAT Study conducted separate scientific discussions reviewing the clinical trial results from the Company's Phase III HEAT Study including new emerging findings from the HEAT Study post-hoc analysis at the 9th Annual Meeting of the World Conference on Interventional Oncology , which is being held on May 16 to 20, 2013 in New York City. The new post-hoc findings suggest that optimized heating cycles markedly improve radiofrequency ablation (RFA) plus ThermoDox's potential for clinically relevant improved progression free survival (PFS) and Overall Survival (OS) outcomes. Professors Poon and Lencioni both concluded that the findings warrant further investigation and development of ThermoDox as a first line treatment for HCC when combined with RFA. The slide presentations are available on the Events and Presentations page on the Celsion website.

"I was pleased to discuss this post-hoc analysis of a large subgroup of patients from the Phase III HEAT Study at the WCIO Conference in New York which may be indicating a meaningful clinical benefit in both PFS and Overall Survival in patients who received an optimized RFA procedure," said Professor Lencioni. "It would appear that the duration of heat from the RFA procedure is a key factor in a successful clinical outcome when combined with ThermoDox as suggested by this analysis. These findings may offer a path forward to potentially offering an important new therapy for HCC patients with limited treatment options."

"This subgroup analysis of approximately 300 patients, although not statistically significant, is nevertheless demonstrating a strong positive trend in both PFS and Overall Survival in ThermoDox® treated patients when heating cycles from the RFA procedure were optimized," said Professor Ronnie Poon. "What we have learned from the HEAT Study is that there is a large cohort of patients that appear to have demonstrated an important benefit from ThermoDox provided the RFA treatment time is properly applied. These findings are quite encouraging and should be confirmed with additional non-clinical studies and clinical trial data."

The data from the HEAT Study post-hoc analysis presented by Professors Lencioni and Poon demonstrate that ThermoDox markedly improves PFS and OS in patients with a single lesion if their lesions undergo RFA for 45 minutes or more. These findings apply to HCC lesion regardless of size and represent a subgroup of approximately 300 patients or 42% of the patients in the HEAT Study. The post-hoc analysis completed by the Company to-date indicates that there may be a large patient cohort that benefited from RFA plus ThermoDox regardless of lesion size.

In the patient subgroup treated in the ThermoDox arm whose RFA procedure lasted longer than 45 minutes and was completed within 90 minutes (40% of single lesion patients), Overall Survival improved by 66% (Hazard Ratio of 0.602) when compared to the control arm of RFA treatment only.
In the patient subgroup treated in the ThermoDox arm whose RFA procedure lasted longer than 90 minutes (23% of single lesion patients), Overall Survival almost doubled (Hazard Ratio of 0.508) when compared to the control arm of RFA treatment only.
When combined, these two subgroups show clinical results that indicated a 53% improvement in Overall Survival, a Hazard Ratio of 0.65, and a Pvalue = 0.105.
In contrast, the patient subgroup treated with ThermoDox whose RFA procedure lasted less than 45 minutes in duration (37% of single lesion patients) indicated that the control arm had an improved Overall Survival benefit when compared to the ThermoDox arm.