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EXHIBIT 5.1
[COOLEY GODWARD LLP LETTERHEAD]
November 9, 2000
AeroGen, Inc.
1310 Orleans Drive
Sunneyvale, CA 94089
Ladies and Gentlemen:
You have requested our opinion with respect to certain matters in connection
with the filing by AeroGen, Inc. (the "Company") of a Registration Statement on
Form S-1 (the "Registration Statement") with the Securities and Exchange
Commission (the "Commission") covering an underwritten public offering of up to
four million one hundred forty thousand (4,140,000) shares of Common Stock (the
"Common Stock").
In connection with this opinion, we have (i) examined and relied upon the
Registration Statement and related Prospectus, the Company's Amended and
Restated Certificate of Incorporation and Bylaws, as currently in effect, and
the originals or copies certified to our satisfaction of such records,
documents, certificates, memoranda and other instruments as in our judgement are
necessary or appropriate to enable us to render the opinion expressed below and
(ii) assumed that the Common Stock will be sold by the Underwriters at a price
established by the Pricing Committee of the Board of Directors of the Company.
On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Common Stock, when sold and issued in accordance with the Registration
Statement and related Prospectus, will be validly issued, fully paid and
non-assessable.
We consent to the reference to our firm under the caption "Legal Matters" in the
Prospectus included on the Registration Statement and to the filing of this
opinion as an exhibit to the Registration Statement.
Very truly yours,
COOLEY GODWARD LLP
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By: /s/ ROBERT J. BRIGHAM
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Robert J. Brigham
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