X0202 4 2005-05-04 0 0001060736 SEATTLE GENETICS INC /WA SGEN 0001307729 Baker Biotech Capital III (GP), LLC 667 MADISON AVENUE NEW YORK NY 10021 1 0 1 0 0001087939 BAKER JULIAN 667 MADISON AVENUE NEW YORK NY 10021 0 0 1 0 0001087940 BAKER FELIX 667 MADISON AVENUE NEW YORK NY 10021 1 0 1 0 Common Stock 2005-05-04 4 P 0 6305 4.7897 A 234861 I See Footnote In addition to Baker Biotech Capital III (GP), LLC, this Form 4 is being filed jointly by Julian C. Baker and Felix J. Baker, each of whom has the same business address as Baker Biotech Capital III (GP), LLC and may be deemed to have a pecuniary interest in securities owned by it. Because of certain relationships with other security holders of the Issuer, the Reporting Persons have filed on Schedule 13D as if they were a member of a group of such shareholders. (Continued in footnote 2.) However, the Reporting Persons disclaim that they and any other person or persons, including those persons with whom the Reporting Persons have filed a Schedule 13D, in fact constitute a "group" for purposes of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, or Rule 13d-5 thereunder or that they are the beneficial owners of securities owned by any such other persons, and each of them disclaims beneficial ownership of securities reported herein except to the extent of their pecuniary interest, if any, therein. Felix J. Baker is a director of the Issuer. Represents shares of common stock owned directly by Baker Biotech Fund III, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital III, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital III (GP), LLC. Felix J. Baker and Julian C. Baker are the controlling members of Baker Biotech Capital III (GP), LLC. /s/ Julian C. Baker, as Managing Member of Baker Biotech Capital III (GP), LLC 2005-05-06 /s/ Julian C. Baker 2005-05-06 /s/ Felix J. Baker 2005-05-06