1 Exhibit 10.10 AMENDMENT NO. 4 to the License Agreement Effective June 1, 1987 Between STANFORD UNIVERSITY and NEORX CORPORATION Effective as of July 11, 1997, THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERITY, a body having corporate powers under the laws of the State of California ("STANFORD") and NEORX CORPORATION, a Washington Corporation, having a principal place of business at 410 W. Harrison, Seattle, Washington 98119 ("NEORX"), agree as follows: AMENDMENT 2.3 - Paragraph 12.3(a) of the License is hereby amended to read in its entirety, as follows: 12.3 (a) - Sublicense terms and conditions shall reflect that any sublicensee shall not further sublicense; provided, however, that NEORX's proposed sublicensee, JANSSEN PHARMACEUTICA, may further sublicense provided that notification is sent to STANFORD upon signing of the sublicense and that any sub-sublicensee may not further sublicense; and IN WITNESS WHEREOF, the parties hereto have executed this Amendment No. 4 in duplicate originals by their duly authorized officers or representatives. THE BOARD OF TRUSTEES NEORX CORPORATION OF THE LELAND STANFORD JUNIOR UNIVERSITY By /s/ [SIGNATURE ILLEGIBLE] By /s/ PAUL G. ABRAMS -------------------------------- --------------------------- Title Director Technology Licensing Title President & CEO -------------------------------- --------------------------- Date July 15, 1997 Date 7/11/97 -------------------------------- ---------------------------