Exhibit 10.34

AMENDMENT NO. 1 TO
INTELLECTUAL PROPERTY SECURITY AGREEMENT

THIS AMENDMENT NO. 1 TO INTELLECTUAL PROPERTY SECURITY AGREEMENT (“Amendment”) is made and entered into as of March 11, 2004 by Aerogen, Inc., a Delaware corporation (the “Borrower”), and the lenders signatory hereto (each lender including their respective successors, endorsees, transferees and assigns, a “Secured Party”, and collectively, the “Secured Parties”).

RECITALS

A.                                    Borrower and Secured Parties have entered into that certain Intellectual Property Security Agreement dated as of September 8, 2003 (the “Original Intellectual Property Security Agreement”) pursuant to which, among other things, Borrower granted a security interest to Secured Parties in certain personal property of Borrower, as more fully set forth therein.

B.                                    Borrower has requested that Secured Parties make a loan to Borrower in the aggregate principal amount of $300,000 (the “Loan”), which Loan will be evidenced by a Secured Debenture Due April 11, 2004 (the “April 2004 Debenture”).

C.                                    Secured Parties are willing to make the Loan and to accept the April 2004 Debenture but only upon the condition that Borrower shall have executed and delivered this Amendment to Secured Parties.  All capitalized terms not otherwise defined herein shall have the meanings given to such terms in the Original Intellectual Property Security Agreement.

AGREEMENT

NOW, THEREFORE, in consideration of the foregoing recitals and the mutual covenants herein set forth, and intending to be legally bound, the parties hereto hereby amend the Original Intellectual Property Security Agreement as follows: