AMENDMENT NO. 3 TO THE DEVELOPMENT AND MANUFACTURING SERVICES AGREEMENT

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                                                                   Exhibit 10.19

                                 AMENDMENT NO. 3

                                       TO

              THE DEVELOPMENT AND MANUFACTURING SERVICES AGREEMENT

                               DATED 08 JANUARY 2004

                                     BETWEEN

                               LONZA BIOLOGICS ***

                                       AND

                          TRUBION PHARMACEUTICALS, INC.

Re:

Schedule 2 - Services

Updated Stages

     Stage 11 ***

Schedule 2

New Stages

     Add Stage 19 ***

     Add Stage 20 ***

     Add Stage 21 ***

Schedule 3

     Price and Payment

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THIS AMENDMENT is made the 7th day of February, 2005

BETWEEN

1.    LONZA BIOLOGICS ***, the registered office of which is at *** ("LB") and

2.    TRUBION PHARMACEUTICALS, INC., of 2401 4th Avenue, Suite 1050, Seattle, WA
     98121, USA (herein after referred to as the "Customer").

WHEREAS

A.    Customer and LB entered into a development and manufacturing services
     agreement dated 08 January 2004 ("the Agreement"), under which LB is
     required to perform Services relating to the Cell Line and the Product, as
     further described in the Agreement, and

B.    Customer would like LB to perform additional services under the Agreement,
     and

C.    LB is prepared to perform the additional services, and the parties wish to
     amend the Agreement accordingly.

NOW THEREFORE it is agreed as follows:

1. Schedule 2 of the Agreement shall be amended to revise Stage 11 (Reference
Standard Characterisation), as follows:

                                   SCHEDULE 2

Stage 11 of Schedule 2 shall now read in its entirety as follows:

STAGE 11 ***

     11.1 OBJECTIVES

           ***

     11.2 ACTIVITIES

          ***

     11.3 DELIVERABLES

          11.3.1 A report of activities carried out under this Stage 11 as
detailed in activity 11.2.4

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     11.4 TIMESCALE

     This Stage will commence as soon as Product is available from Stage 6 and
will be complete on issue of the final report of activities (activity 11.2.6)
and it is estimated that this shall be issued *** from the issue of protocol.


                                       -2-

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     2. Schedule 2 of the Agreement shall be amended to include the following
additional stages, Stage 19 (Stability Study (*** Pilot Material)), Stage 20
(Product Characterisati