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                                                                Exhibit 10.14

                            NEGATIVE PLEDGE AGREEMENT

            THIS NEGATIVE PLEDGE AGREEMENT is made as of September 7, 2004, by
and between ("BORROWER") and LIGHTHOUSE CAPITAL PARTNERS V, L.P. ("LENDER").

      In connection with the Loan Documents being concurrently executed between
Borrower and Lender, Borrower agrees as follows:

      Except as otherwise permitted in the Loan Documents or pursuant to a
licensing, development or other partnering transaction or other business
relationship related to the use or development of Borrower's intellectual
property (a) that is in the Borrower's ordinary course of business, or (b) that
is not material to the financial condition or results of operations of the
Borrower and in which the Borrower receives adequate consideration, or (c) that
is approved by the Borrower's Board of Directors consistent with the Delaware
General Corporation Law, Borrower shall not sell, transfer, assign, mortgage,
pledge, lease, grant a security interest in, or encumber any of Borrower's
intellectual property, including, without limitation, the following:

  1)  Any and all copyright rights, copyright applications, copyright
      registration and like protection in each work or authorship and derivative
      work thereof, whether published or unpublished and whether or not the same
      also constitutes a trade secret, now or hereafter existing, created,
      acquired or held (collectively, the "COPYRIGHTS");

  2)  Any and all trade secrets, and any and all intellectual property rights in
      computer software and computer software products now or hereafter
      existing, created, acquired or held;

  3)  Any and all design rights which may be available to Borrower now or
      hereafter existing, created, acquired or held;

  4)  All patents, patent applications and like protections, including, without
      limitation, improvements, divisions, continuations, renewals, reissues,
      extensions and continuations-in-part of the same, including, without
      limitation, the patents and patent applications (collectively, the
      "PATENTS");

  5)  Any trademark and servicemark rights, whether registered or not,
      applications to register and registrations of the same and like
      protections, and the entire goodwill of the business of Borrower connected
      with and symbolized by such trademarks (collectively, the "TRADEMARKS");

  6)  All licenses or other rights to use any of the Copyrights, Patents or
      Trademarks and all license fees and royalties arising from such use to the
      extent permitted by such license or rights; and

  7)  All amendments, extensions, renewals and extensions of any of the
      Copyrights, Patents or Trademarks; and

            It shall be an Event of Default under the Loan Documents between
Borrower and Lender if there is a breach of any term of this Negative Pledge
Agreement.

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            Capitalized items used herein without definition shall have the same
meanings as set forth in the Loan and Security Agreement of even date herewith.

BORROWER:                               LENDER:

COMBINATORX, INCORPORATED               LIGHTHOUSE CAPITAL PARTNERS V, L.P.

By: /s/ Robert Forrester                BY:     LIGHTHOUSE MANAGEMENT PARTNERS
   --------------------------------             V, L.L.C., its general partner

Name: Robert Forrester
     --------------------------------

Title: CFO                             By: /s/ Thomas Conneely
      -------------------------------      ---------------------------

                                        Name: Thomas Conneely
                                             ------------------------

                                        Title: Vice President
                                              ------------------------

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