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EXHIBIT 4.3
TRUBION PHARMACEUTICALS, INC.
AMENDMENT NO. 1 TO
AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT
This
Amendment No. 1 to the Amended and Restated Investor Rights
Agreement
(the "RIGHTS AGREEMENT") dated as of July 13, 2004 is entered into
as of
________, 2005, by and among Trubion Pharmaceuticals, Inc., a
Delaware
corporation (the "COMPANY"), Wyeth, a Delaware corporation
("WYETH"), and the
investors set forth on EXHIBIT A hereto (collectively the
"INVESTORS" and each
individually an "INVESTOR").
RECITALS
A.
The Company and the Investors are parties to the Rights
Agreement.
B.
The Company and Wyeth have entered into a Common Stock Purchase
Agreement dated as of December ___, 2005 (the "PURCHASE AGREEMENT")
pursuant to
which the Company will sell to Purchaser and Purchaser will
purchase from the
Company shares of the Company's Common Stock concurrent with and
conditioned
upon the closing of the Company's initial public offering (the
"CLOSING"). A
condition to the Purchaser's obligations under the Purchase
Agreement is that
the Rights Agreement be amended in order to provide Purchaser with
certain
rights to register shares of the Company's Common Stock.
C.
Pursuant to Section 6.5 of the Rights Agreement, the written
consent of
the Company and the Investors holding a majority of the Registrable
Securities
(the "REQUISITE HOLDERS") is required to amend the Rights
Agreement.
D.
The Company and the Requisite Holders desire to induce Purchaser
to
enter into the Purchase Agreement by agreeing to the terms and
conditions set
forth herein.
NOW, THEREFORE, in
consideration of the mutual promises, representations,
warranties, covenants and conditions set forth in this Agreement,
the parties
hereto agree as follows:
1.
Definitions. Capitalized terms used herein without definition shall
have
the meaning ascribed to them in the Rights Agreement.
2.
Addition of Purchaser as a Party to the Rights Agreement. Effective
upon
the Closing pursuant to the Purchase Agreement, the parties hereby
agree to add
Purchaser as a party to the Rights Agreement and Purchaser shall be
deemed a
"Holder" of Registrable Securities for purposes of Sections 1, 2
and 6 of the
Rights Agreement and subject to all of the rights and obligations
of such
Sections. For purposes of clarification, Purchaser shall not be
entitled to the
rights or subject to the obligations set forth in Sections 3, 4 and
5 of the
Rights Agreement and Purchaser shall not be deemed an "INVESTOR"
for purposes of
the Rights Agreement..
3.
Amendment to Section 1.1. The definition of "Registrable
Securities" set
forth in Section 1.1 is hereby amended and restated to read in its
entirety as
follows:
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"REGISTRABLE SECURITIES" means (a) Common Stock of the Company
issued
or issuable upon conversion of the Shares, (b) Common Stock of the
Company
issued to Frazier Healthcare Fund ("FRAZIER"), ARCH Venture Fund
("Arch") and
Scott Minick ("MINICK") pursuant to those certain Common Stock
Purchase
Agreements dated November 19, 2002 by and between the Company and
each of
Frazier, Arch and Minick, (c) Common Stock of the Company issued to
Wyeth
pursuant to the Purchase Agreement, and (d) any Common Stock of the
Company
issued as (or issuable upon the conversion or exercise of any
warrant, right or
other security which is issued as) a dividend or other distribution
with respect
to, or in exchange for or in replacement of, the securities
described in (a),
(b) and (c) above; provided, however, the shares referred to in
clause (c) above
shall not qualify as Registrable Securities for the purposes of
Sections 2.2
hereof until the 15 month anniversary of the Closing. For the
avoidance of
doubt, in the event that the Company effects a registration under
the Securities
Act pursuant to Section 2.2 hereof prior to the 15 month
anniversary of the
Closing, in connection with such registration the Shares referred
to in clause
(c) above shall qualify as Registrable Securities for the purposes
of Section
2.3. Notwithstanding the foregoing, Registrable Securities shall
not include any
securities sold by a person to the public pursuant to a
registration statement
or Rule 144 or sold in a private transaction in which the
transferor's rights
under SECTION 2 of this
