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                                                                  Exhibit 10.24

                AMENDMENT TO STOCK PURCHASE PLEDGE AGREEMENT AND

                           STOCK RESTRICTION AGREEMENT

         This Amendment to Stock Purchase Pledge Agreement and Stock Restriction
Agreement (this "AMENDMENT") is made as of the _30th_ day of _July_______, 2003,
by and between Advancis Pharmaceutical Corporation, a Delaware corporation
("PLEDGEE") and Edward M. Rudnic, Ph.D. ("PLEDGOR"). All capitalized terms used
in this Amendment and not otherwise defined herein shall have the meanings
assigned to those terms in the Pledge Agreement (as defined below).

         WHEREAS, Pledgor previously executed that certain Stock Purchase Pledge
Agreement dated October 15, 2001, as amended (the "PLEDGE AGREEMENT"), for the
benefit of Pledgee and pursuant to which Pledgor pledged and granted to Pledgee
a security interest in the Pledged Collateral, including 420,000 shares of
Common Stock (the "PLEDGED SHARES"), and Pledgor agreed to not sell or otherwise
dispose of the Pledged Shares;

         WHEREAS, simultaneously with the execution of the Pledge Agreement,
Pledgee executed that certain Stock Restriction Agreement dated October 15, 2001
(the "RESTRICTION AGREEMENT");

         WHEREAS, Pledgor subsequently entered into an Amendment to Stock
Purchase Pledge Agreement dated June 12, 2002 pursuant to which Pledgee gave
Pledgor the right to transfer up to 200,000 Pledged Shares to (a) the Pledgor's
child, stepchild, grandchild, parent, stepparent, grandparent, spouse, former
spouse, sibling, niece, nephew, mother-in-law, father-in-law, son-in-law,
daughter-in-law, brother-in-law, or sister-in-law, including adoptive
relationships, or any persons sharing the Pledgor's household (other than a
tenant or employee of the stockholder) ("FAMILY MEMBERS"), (b) a trust in which
Family Members have more than 50% of the beneficial interest, (c) a foundation
in which Family Members (or the Pledgor) control the management of assets, or
(d) any other entity in which Family Members (or the Pledgor) own more than 50%
of the voting interests;

         WHEREAS, Pledgor and Pledgee desire to amend the Pledge Agreement to
allow Pledgor to transfer by gift up to 20,000 vested Pledged Shares to certain
other persons for each such person's benefit.

         NOW, THEREFORE, in consideration of the premises and the mutual
promises set forth herein, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties agree as
follows:

         1. Transfers. Notwithstanding anything in the Pledge Agreement to the
contrary, Pledgor shall have the right to transfer by gift up to 20,000 vested
Pledged Shares to up to two persons (or trusts for their benefit) to be selected
by Pledgor.

         2. Amendments. Except as explicitly provided in this Amendment, there
are no changes or amendments to the Pledge Agreement or the Restriction
Agreement. All provisions contained in the Pledge Agreement and the Stock
Restriction Agreement that are not explicitly


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amended hereby are and shall remain in full force and effect. In the event of
any conflict between the provisions of this Amendment and the provisions of the
Pledge Agreement and The Stock Restriction Agreement, the provisions of this
Amendment shall control.

                   [ signatures appear on the following page ]


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         IN WITNESS WHEREOF, the parties hereto have executed this Amendment as
of the day and year first above written.

                                 ADVANCIS PHARMACEUTICAL CORPORATION

                                 By:  /s/ James D. Isbister
                                      ------------------------------------
                                      James D. Isbister
                                      Chairman of the Board

                                 STOCKHOLDER

                                      /s/ Edward M. Rudnic
                                      ------------------------------------
                                      Edward M. Rudnic, Ph.D.


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