EXHIBIT 10.52

 

[ * ] = Certain confidential information contained in this document, marked by
brackets, has been omitted and filed separately with the Securities And Exchange
Commission pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as
amended.

 

November 30, 2005

 

Chris Penland, Ph.D.

Cystic Fibrosis Foundation Therapeutics, Inc.

6931 Arlington Road

Bethesda, MD 20814

 

Dear Dr. Penland:

 

The purpose of this letter (“Letter”) is to amend the Study Funding Agreement,
between the undersigned parties, dated June 17, 2003, as amended (the
“Agreement”). By signing below, the undersigned parties agree to the following:

 

In Section 8.1(c) of the Agreement, [ * ] shall be replaced with [ * ].

 

All other terms and provisions of the Agreement shall remain unchanged and are
in full force and effect.

 

HOLLIS-EDEN PHARMACEUTICALS, INC.

        By:   /s/    ERIC J. LOUMEAU               Date: December 13, 2005    

Eric J. Loumeau

Vice President, General Counsel

           

 

Agreed to and Acknowledged by:

 

CYSTIC FIBROSIS FOUNDATION THERAPEUTICS, INC.

        By:   /s/    ROBERT J. BEALL               Date: December 9, 2005    

Robert J. Beall, Ph.D.

President and CEO