Exhibit 10.12.2

SECOND AMENDMENT

THIS SECOND AMENDMENT(the "Amendment") is made and entered into as of the 9th day of March, 2004,
by and betweenCA-SHORELINE TECHNOLOGY PARK LIMITED PARTNERSHIP,a Delaware limited
partnership("Landlord"), andAEROGEN, INC.,a Delaware corporation("Tenant"),

RECITALS

NOW, THEREFORE,in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, Landlord and Tenant agree as follows:

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Period

Annual Rate
Per Square
Foot

Monthly
Base RentDate of this Amendment - December 31, 2004

$
37.10

$
99,390.90January 1, 2005 - December 31, 2005

$
38.30

$
102,605.70January 1, 2006 - February 28, 2006

$
39.55

$
105,954.45March 1, 2006 - December 31, 2006

$
39.55

$
105,954.45January 1, 2007 - February 28, 2007

$
40.84

$
109,410.36March 1, 2007 - December 31, 2007

$
40.84

$
109,410.36January 1, 2008 - February 29, 2008

$
42.16

$
112,946.64March 1, 2008 - December 31, 2008

$
42.16

$
112,946.64January 1, 2009 - February 28, 2009

$
43.53

$
116,616.87




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|Period                                     |  | Monthly Base
Rent Before
Abatement |           | Abated Base Rent
Amount |   | Monthly
Base Rent After
Abatement
|------------------------------------------ |  | ---------------------------------- | --------- | ----------------------- | - | ---------------------------------
|Date of this Amendment - December 31, 2004 |  | $                                  | 99,390.90 |                         | $ | 43,131.90                        
|January 1, 2005 - December 31, 2005        |  | $                                  | 46,346.70 |                         | $ | 102,605.70                       
|January 1, 2006 - February 28, 2006        |  | $                                  | 49,695.45 |                         | $ | 105,954.45                       
|March 1, 2006 - December 31, 2006          |  | $                                  | 33,621.45 |                         | $ | 105,954.45                       
|January 1, 2007 - February 28, 2007        |  | $                                  | 37,077.36 |                         | $ | 109,410.36                       
|March 1, 2007 - December 31, 2007          |  | $                                  | 32,898.12 |                         | $ | 109,410.36                       
|January 1, 2008 - February 29, 2008        |  | $                                  | 36,434.40 |                         | $ | 112,946.64                       
|March 1, 2008 - December 31, 2008          |  | $                                  | 32,255.16 |                         | $ | 112.946.64                       
|January 1, 2009 - February 28, 2009        |  | $                                  | 35,925.39 |                         | $ | 116,616,87                       



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[SIGNATURES ARE ON FOLLOWING PAGE]

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IN WITNESS WHEREOF, Landlord and Tenant have duly executed this Amendment as of the day and year first above written.

| |  | LANDLORD:                                                                       
| |  | --------------------------------------------------------------------------------
| |  | CA-SHORELINE TECHNOLOGY PARK LIMITED PARTNERSHIP, a Delaware limited partnership
| |  | By:                                                                             
| |  |                                                                                 
| |  |                                                                                 
| |  |                                                                                 
| |  |                                                                                 
| |  | TENANT:                                                                         
| |  | AEROGEN, INC., a Delaware corporation                                           
| |  | By:                                                                             
| |  | Name:                                                                           
| |  | Title:                                                                          
| |  | 33-0488580Tenant's Tax ID Number (SSN or FEIN)                                  

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EXHIBIT AOUTLINE AND LOCATION OF REDUCTION SPACE

MAP

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MAP

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EXHIBIT BINVESTMENT REPRESENTATION LETTER

Aerogen, Inc.
2071 Stierlin Court
Mountaln View, CA 94043-4655

Ladies
and Gentlemen:

The
undersigned hereby makes the following certifications and representations with respect to the Fifty Thousand (50,000) shares (the "Shares") of Common Stock of AEROGEN, INC., a
Delaware corporation (the "Company"), which are being acquired by the undersigned pursuant to the Second Amendment dated March    , 2004 to the Lease Agreement dated as of October 1,
2001.

The
undersigned is an "accredited investor"" as that term is defined in Regulation D of the Securities Act of 1933, as amended (the "Securities Act").

The
undersigned represents and warrants that the undersigned is acquiring the Shares solely for the undersigned's account for investment and not with a view to or for sale or
distribution of the Shares or any part thereof. The undersigned also represents that the entire legal and beneficial interests of the Shares the undersigned is acquiring is being acquired for, and
will be held for, the undersigned's account only.

The
undersigned understands that the Shares have not been registered under the Securities Act of 1933, as amended (the "Securities Act"), on the basis that no distribution or public
offering of the Shares is to be effected. The undersigned realizes that the basis for the exemption may not be present
if, notwithstanding the undersigned's representations, the undersigned has in mind merely acquiring the Shares for a fixed or determinable period in the future, or for a market rise, or for sale if
the market does not rise. The undersigned has no such intention.

The
undersigned recognizes that the Shares being acquired by the undersigned must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption
from such registration is available.

The
undersigned is aware that the Shares may not be sold pursuant to Rule 144 adopted under the Securities Act ("Rule 144") unless certain conditions are met and until the
undersigned has held the Shares for at least one year. Among the conditions for use of the Rule is the availability of current information to the public about the Company,

The
undersigned further agrees not to make any disposition of all or any part of the Shares being acquired in any event unless and until:



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The
undersigned understands and agrees that all certificates evidencing the Shares to be issued to the undersigned may bear the following legend:



|Very truly yours,                               
|------------------------------------------------
|CA-SHORELINE TECHNOLOGY PARK LIMITED PARTNERSHIP
|                                                
|                                                
|                                                
|                                                
|                                                

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EXHIBIT CCAPITALIZATION OF THE TENANT

As
of March 3, 2004:

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EXHIBIT DTERMS OF THE REGISTRATION OF COMMON STOCK

1.Expenses.Tenant will pay all expenses associated with the Registration Statement.

2.Indemnification.Tenant will indemnify and hold harmless Landlord, its directors, officers, agents and
employees, each Person who controls the Landlord (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers, agents or
employees of such controlling Persons, to the fullest extent permitted by applicable law, from and against any and all losses, claims, damages, liabilities, costs (including, without limitation,
reasonable costs of preparation and reasonable attorneys' fees) and expenses (collectively, "Losses"), as incurred, arising out of or relating to any
untrue or alleged untrue statement of a material fact contained in the Registration Statement, any Prospectus or any form of prospectus or in any amendment or supplement thereto or in any preliminary
prospectus, or arising out of or relating to any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein (in the case of any
Prospectus or form of prospectus or supplement thereto, in light of the circumstances under which they were made) not misleading, except to the extent but only to the extent, that (1) such
untrue statements or omissions are based solely upon information regarding Landlord furnished in writing to Tenant by Landlord expressly for use therein, or to the extent that such information relates
to Landlord or Landlord's proposed method of distribution of registrable securities and was reviewed and expressly approved in writing by Landlord expressly for use in the Registration Statement, such
Prospectus or such form of Prospectus or in any amendment or supplement thereto (it being understood that Landlord has approved Annex A hereto for this purpose) or (2) the use by Landlord of an
outdated or defective Prospectus after Tenant has notified Landlord in writing that the Prospectus is outdated or defective and prior to the receipt by Landlord of a written advice that use of the
Prospectus may be resumed (an "Advice") or an amended or supplemented Prospectus, but only if and to the extent that following the receipt of the Advice
or amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected.

Landlord
will indemnify and hold harmless Tenant, its directors, officers, agents and employees, each Person who controls Tenant (within the meaning of Section 15 of the
Securities Act and Section 20 of the Exchange Act), and the directors, officers, agents or employees of such controlling Persons, to the fullest extent permitted by applicable law, from and
against all Losses, as incurred, arising solely out of or based solely upon: (x) Landlord's failure to comply with the prospectus delivery requirements of the Securities Act or (y) any
untrue statement of a material fact contained in any Registration Statement, any prospectus, or any form of prospectus, or in any amendment or supplement thereto, or arising solely out of or based
solely upon any omission of a material fact required to be stated therein or necessary to make the statements therein not misleading to the extent, but only to the extent that, (1) such untrue
statements or omissions are based solely upon information regarding Landlord furnished in writing to Tenant by Landlord expressly for use therein, or to the extent that such information relates to
Landlord or Landlord's proposed method of distribution of registrable securities and was reviewed and expressly approved in writing by Landlord expressly for use in the Registration Statement (it
being understood that Landlord has approved Annex A hereto for this purpose), such Prospectus or such form of Prospectus or in any amendment or supplement thereto or (2) the use by Landlord of
an outdated or defective Prospectus after Tenant has notified Landlord in writing that the Prospectus is outdated or defective and prior to the receipt by Landlord of an Advice or an amended or
supplemented Prospectus, but only if and to the extent that following the receipt of the Advice or the amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would
have been corrected. In no event shall the liability of Landlord be greater in amount than the dollar amount of the net proceeds received by Landlord upon the sale of the registrable securities giving
rise to such indemnification obligation.

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3.Registration.The Registration Statement will be on Form S-3 (except if Tenant is not
S-3 eligible, in which case the Registration Statement will be on another appropriate form) and shall contain (except if otherwise required by the Securities and Exchange Commission
("Commission")) the "Plan of Distribution" in substantially the form attached hereto as Annex A. The Tenant
shall use its best efforts to keep such Registration Statement continuously effective under the Securities Act until the date which
is two years after the date that such Registration Statement is declared effective by the Commission or such earlier date when all registrable securities covered by a Registration Statement have been
sold or may be sold without volume restrictions pursuant to Rule 144(k) as determined by the counsel to Tenant pursuant to a written opinion letter to such effect, addressed and acceptable to
Tenant's transfer agent.

4.Procedures.Tenant shall furnish to Landlord, without charge, as many copies of each Prospectus or
Prospectuses (including each form of prospectus) and each amendment or supplement thereto as Landlord may reasonably request. Prior to any public offering of registrable securities, Tenant shall use
its best efforts to register or qualify or cooperate with Landlord in connection with the registration or qualification (or exemption from such registration or qualification) of such registrable
securities for offer and sale under the securities or Blue Sky laws of all jurisdictions within the United States, to keep each such registration or qualification (or exemption therefrom) effective
during the Effectiveness Period and to do any and all other acts or things necessary or advisable to enable the disposition in such jurisdictions of the registrable securities covered by the
Registration Statements;provided, that Tenant shall not be required to qualify generally to do business in any jurisdiction where it is not then
so qualified or subject Tenant to any material tax in any such jurisdiction where it is not then so subject.

Upon
the occurrence of any event or passage of time that makes the financial statements included in the Registration Statement ineligible for inclusion therein or any statement made in
the Registration Statement or Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue in any material respect or that requires any revisions to the
Registration Statement, Prospectus or other documents so that, in the case of the Registration Statement or the Prospectus, as the case may be, it will not contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, Tenant
shall, as promptly as reasonably possible, prepare a supplement or amendment, including a post-effective amendment, to the Registration Statement or a supplement to the related Prospectus
or any document incorporated or deemed to be incorporated therein by reference, and file any other required document so that, as thereafter delivered, neither the Registration Statement nor such
Prospectus will contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances
under which they were made, not misleading. If in accordance with (i) any request by the Commission or any other Federal or state governmental authority during the period of effectiveness of
the Registration Statement for amendments or supplements to the Registration Statement or Prospectus or for additional information; (ii) the issuance by the Commission or any other federal or
state governmental authority of any stop order suspending the effectiveness of the Registration Statement covering any or all of the registrable securities or the initiation of any proceedings for
that purpose; or (iii) the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from qualification of any of the registrable securities
for sale in any jurisdiction, or the initiation or threatening of any proceeding for such purpose, Tenant notifies Landlord to suspend the use of any Prospectus until the requisite changes to such
Prospectus have been made, then Landlord shall suspend use of such Prospectus. Tenant will use its best efforts to ensure that the use of the Prospectus may be resumed as promptly as is practicable.
Tenant shall be entitled to exercise the right to suspend the availability of a Registration Statement and Prospectus for a period not to exceed 60 days (which need not be consecutive days) in
any 12 month period.

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ANNEX APlan of Distribution

The selling stockholders, which as used herein includes donees, pledgees, transferees or other successors-in-interest selling shares of
common stock or interests in shares of common stock received after the date of this prospectus from a selling stockholder as a gift, pledge, partnership distribution or other transfer, may, from time
to time, sell, transfer or otherwise dispose of any or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility on which the shares
are traded or in private transactions. These dispositions may be at fixed prices, at prevailing market prices at the time of sale, at prices related to the prevailing market price, at varying prices
determined at the time of sale, or at negotiated prices.

The
selling stockholders may use any one or more of the following methods when disposing of shares or interests therein:



The
selling stockholders may, from time to time, pledge or grant a security interest in some or all of the shares of common stock owned by them and, if they default in the performance of
their secured obligations, the pledgees or secured parties may offer and sell the shares of common stock, from time to time, under this prospectus, or under an amendment to this prospectus under
Rule 424(b)(3) or other applicable provision of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling
stockholders under this prospectus. The selling stockholders also may transfer the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in
interest will be the selling beneficial owners for purposes of this prospectus.

In
connection with the sale of our common stock or interests therein, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions,
which may in turn engage in short sales of the common stock in the course of hedging the positions they assume. The selling stockholders may also sell shares of our common stock short and deliver
these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that in turn may sell these securities. The selling stockholders may also enter into option or
other transactions with broker-dealers or other financial Institutions or the creation of one or more derivative securities which require the delivery to such broker-dealer or other financial
institution of shares offered by this prospectus,

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which
shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The
aggregate proceeds to the selling stockholders from the sale of the common stock offered by them will be the purchase price of the common stock less discounts or commissions, if any.
Each of the selling stockholders reserves the right to accept and, together with their agents from time to time, to reject, in whole or in part, any proposed purchase of common stock to be made
directly or through agents. We will not receive any of the proceeds from this offering.

The
selling stockholders also may resell all or a portion of the shares in open market transactions in reliance upon Rule 144 under the Securities Act of 1933, provided that they
meet the criteria and conform to the requirements of that rule.

The
selling stockholders and any underwriters, broker-dealers or agents that participate in the sale of the common stock or interests therein may be "underwriters" within the meaning of
Section 2(11) of the Securities Act. Any discounts, commissions, concessions or profit they earn on any resale of the shares may be underwriting discounts and commissions under the Securities
Act. Selling stockholders who are "underwriters" within the meaning of Section 2(11) of the Securities Act will be subject to the prospectus delivery requirements of the Securities Act.

To
the extent required, the shares of our common stock to be sold, the names of the selling stockholders, the respective purchase prices and public offering prices, the names of any
agents, dealer or underwriter, any applicable commissions or discounts with respect to a particular offer will be set forth in an accompanying prospectus supplement or, if appropriate, a
post-effective amendment to the registration statement that includes this prospectus.

In
order to comply with the securities laws of some states, if applicable, the common stock may be sold in these jurisdictions only through registered or licensed brokers or dealers. In
addition, in some states the common stock may not be sold unless it has been registered or qualified for sale or an exemption from registration or qualification requirements is available and is
complied with.

We
have advised the selling stockholders that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of shares in the market and to the
activities of the selling stockholders and their affiliates. In addition, we will make copies of this prospectus (as it may be supplemented or amended from time to time) available to the selling
stockholders for the purpose of satisfying the prospectus delivery requirements of the Securities Act. The selling stockholders may indemnify any broker-dealer that participates in transactions
involving the sale of the shares against certain liabilities, including liabilities arising under the Securities Act.

We
have agreed to indemnify the selling stockholders against liabilities, including liabilities under the Securities Act and state securities laws, relating to the registration of the
shares offered by this prospectus.

We
have agreed with the selling stockholders to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (1) such time as all of
the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement or (2) the date on which the shares may be sold pursuant to
Rule 144(k) of the Securities Act.

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