EXHIBIT 10.12
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                                     (Logo)

                          Office of Industrial Affairs

                                                                  August 31.1999

John Mon
General Manager
Celsion Corporation
10220-1 Old Columbia Road
Columbia, MD 21046-1705


Dear John:

It was a pleasure  speaking  with you last week.  This letter will  confirm that
April 9, 1999 is the accurate  effective  date of the Option  Agreement  between
Sloan-Kettering  Institute for Cancer Research and Celsion Corporation signed on
February  26,  1999.  The  revised   effective  date  was  agreed  to  during  a
conversation  between  you and  Steve  Bertha  in March  but has not been made a
formal  amendment to the agreement.  If Celsion would like a formal amendment to
the option agreement, then we will prepare one. The option period will expire on
November 9, 1999.

Please do not hesitate to contact me if you have any  questions.  I look forward
to our upcoming meeting.


                                                Sincerely,

                                                /s/Jennifer A. Brooks
                                                ---------------------
                                                Jennifer A. Brooks
                                                Licensing Associate


                     Memorial Sloan-Kettering Cancer Center
                   1275 York Avenue, New York, New York l0021
                   NCI-designated Comprehensive Cancer Center