**Exhibit 10.35**

**FOURTHAMENDMENT**

**THIS****FOURTH AMENDMENT** (this “**Fourth Amendment**”)is made and entered into as of the 30th day ofNovember, 2006, by and between **CA-FOOTHILLRESEARCH CENTER LIMITED PARTNERSHIP, a Delaware limited partnership** (“**Landlord**”), and**AFFYMAX, INC., a Delaware corporation** (“**Tenant**”).

**RECITALS**

A.**                                  **Landlord(as successor in interest by conversion to EOP-Foothill Research Center, L.L.C., a Delaware limited liabilitycompany, successor ininterest to Spieker Properties, L.P., a California limited partnership,successor in interest to Miranda Associates, a California general partnership),as landlord, and Tenant (as successor in interest to Affymax ResearchInstitute, a California corporation), as tenant, are parties to that certainResearch and Development/Office Lease dated May 30, 1990 (the “**Original Lease**”), as amended by  that certain Consent to Sublease dated July30, 1990 (the “**Consent**”), that certain FirstAmendment to Lease dated November 16, 1999 (the “**FirstAmendment**”), that certain Second Amendment to Lease dated December20, 1999 (the “**Second Amendment**”), and thatcertain Third Amendment dated December 31, 2001 (the “**ThirdAmendment**”), (collectively, the “**Lease**”)pursuant to which Landlord has leased to Tenant certain premises containingapproximately 53,830 rentable square feet (referred to herein as the “**Initial****Premises**”)consisting of the entire building commonly known as 4001 Miranda Avenue locatedat 4001 Miranda Avenue, Palo Alto, California (the “**4001 Miranda****Building**”).

B.**                                    **Tenant has requested that additional spacecontaining approximately **30,630**rentablesquare feet consisting of the entire 2-story building****knownas 4015 Miranda Avenue (the “**4015 Miranda****Building**”), as moreparticularly shown on **Exhibit A**hereto (the “**Must-Take Space**”) be added to thePremises following the expiration of the existing tenant’s lease for theMust-Take Space and that the Lease be appropriately amended, and Landlord iswilling to do the same on the following terms and conditions.  The existing tenant of the Must-Take Space isTibco Software, Inc., a Delaware corporation (“**Tibco**”),pursuant to a lease dated January 21, 2000 (the “**ExistingLease**”). Tibco has subleased the Must-Take Space to Tenant pursuantto a Sublease dated September 1, 2006 (the “**TibcoSublease**”), the term of which is scheduled to expire on December 31,2010, and Landlord has consented to the Tibco Sublease pursuant to the terms ofthat certain Consent to Sublease of approximately even date herewith.

C.                                     As described in the Lease, the 4001 MirandaBuilding and the 4015 Miranda Building are part of a project known as theFoothill Research Center, which currently also includes the buildings locatedat 4005 Miranda Avenue (the “**4005 Miranda Building**”)and at 4009 Miranda Avenue (the “**4009 Miranda Building**”).

D.**                                   **The Lease by its terms shall expire on September30, 2007 (“**Prior Termination Date**”), and theparties desire to extend the term of the Lease (the “**Term**”),all on the following terms and conditions.

**NOW, THEREFORE,** in consideration of the mutual covenants andagreements herein contained and other good and valuable consideration, thereceipt and sufficiency of which are hereby acknowledged, Landlord and Tenantagree as follows:

I.**                                         Expansion: Must-Take Space.**

A.                                   **Must-Take Space.** Tenant shall be required to lease fromLandlord and Landlord shall be required to lease to Tenant the Must-Take Space(as defined in Recital B above).

B.                                     **Must-Take Effective Date.**

1.                                       Subjectto Subsection E below, Landlord shall deliver possession of the Must-Take Spaceto Tenant and Tenant shall accept such space on January 1, 2011 (the “**Must-Take Effective Date**”). The Term with respect to the Must-Take Space (the “**Must-TakeTerm**”) shall commence on the Must-Take Effective Date and end,unless sooner terminated pursuant to the terms of the Lease, as amended hereby,on the Extended Termination Date (as defined below), it being the intention

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of the parties hereto that the term for the Must-TakeSpace and the Extended Term for the Initial Premises shall be coterminous.  TheMust-Take Effective Date shall be delayed to the extent that Landlord fails todeliver possession of the Must-Take Space for any reason, including but notlimited to, holding over by prior third party occupants.  Any such delay in the Must-Take EffectiveDate shall not subject Landlord to any liability for any loss or damageresulting therefrom; provided, however, Landlord, at its expense, shall usecommercially reasonable efforts to obtain possession of the Must-Take Space fordelivery to Tenant as soon as practicable following any such holdover.  If the Must-Take Effective Date is delayed,the Extended Termination Date shall not be similarly extended.  If Tenant is in occupancy of the Must-TakeSpace pursuant to the Tibco Sublease on the day preceding the Must-TakeEffective Date, the Tibco Sublease shall be deemed terminated and Tenant shallbe deemed to have taken possession of the Must-Take Space pursuant to the termsof this Fourth Amendment as of the Must-Take Effective Date.

2.                                       Asof the Must-Take Effective Date, the Must-Take Space shall become part of thePremises and the “Premises”, as defined in the Lease, shall be increased from53,830 rentable square feet in the 4001 Miranda Building to **84,460**rentable square in the 4001 Miranda Building and the4015 Miranda Building by the addition of the Must-Take Space, subject to themodifications to the Lease set forth in this Fourth Amendment.  The Must-Take Space shall be subject to allthe terms and conditions of the Lease except as expressly modified herein andexcept that Tenant shall not be entitled to receive any allowances, abatementsor other financial concessions granted with respect to the Initial Premisesexcept as expressly provided in this Section I.

C.                                     **Rent for Must-Take Space.**

1.                                      Theinitial Base Rent rate per rentable square foot for the Must-Take Space duringthe first year of the Must-Take Term (the “**Initial Base Rent**”)shall equal the Prevailing Market (hereinafter defined) rate per rentablesquare foot for the Must-Take Space, subject to the Minimum Initial Base Rentand Maximum Initial Base Rent, all as set forth below.  Base Rentduring the Must-Take Term shallincrease on each anniversary of the Must-Take Effective Date by three percent(3%) of the Base Rent for the previous period. Base Rent attributable to the Must-Take Space shall be payable inmonthly installments in accordance with the terms and conditions of Section 4of the Lease, provided that the CPI adjustments set forth in Paragraph 2 of theFirst Amendment and Section 4(b) of the Lease shall not apply to the Must-TakeSpace.

2.                                      Duringthe Must-Take Term,****Tenant shallpay Property Expenses for the Must-Take Space on the same terms and conditionsset forth in the Lease, as amended by this Fourth Amendment, except that inconnection with the Must-Take Space, for purposes of Sections 6 and 47 of theLease the “Premises” shall mean the Must-Take Space, the “Building” shall meanthe 4015 Miranda Building, and “Tenant’s Percentage” for the Must-Take Spaceshall be **15.9432%**.

D.                                    **Must-Take SpaceImprovements. **The Must-Take Space (including improvements andpersonalty, if any) shall be accepted by Tenant in its as-built, “as-is”condition and configuration existing on the Must-Take Effective Date, includingany improvements performed by Tenant during the term of the Tibco Sublease, ifany.** **Followingthe Must-Take Effective Date, Tenant may perform improvements to the Must-TakeSpace in accordance with the Must-Take Work Letter attached hereto as **Exhibit B** and Tenant shall be entitled to an improvementallowance in connection with such work as more fully described in **Exhibit B**.  Anyimprovements performed by Tenant to the Must-Take Space shall be subject toSection 12 of the Lease.  Landlord andTenant acknowledge that Tenant may perform improvements in the Must-Take Spaceduring Tenant’s possession thereof pursuant to the Tibco Sublease, and that anysuch improvements shall be subject to the terms of the Existing Lease and theTibco Sublease (all as defined in Recital B). Any such improvements performed in the Must-Take Space during Tenant’spossession pursuant to the Tibco Sublease

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shallbe considered “Tenant Improvements” under the Lease effective upon theMust-Take Effective Date, including for purposes of categorization of suchimprovements pursuant to Section 12.B and **Exhibit E**ofthe Original Lease, as though the same had been performed during the Must-TakeTerm.

E.                                      **Existing Lease.**  Ifthe Existing Lease terminates with respect to the Must- Take Space prior toDecember 31, 2010 and the Tibco Sublease has not been previously terminated forany reason, the Tibco Sublease automatically shall be deemed terminated as ofthe date of termination of the Existing Lease (the “**EarlyTermination Date**”), the Must-Take Effective Date automatically shallbe accelerated to the day immediately following the Early Termination Date (the“**Advance Must-Take Effective Date**”),Tenant shall be deemed to have taken possession of the Must-Take Space pursuantto the terms of the Lease and this Must-Take provision as of the AdvanceMust-Take Effective Date, and the terms and conditions of this Lease applicableto the Must-Take Space shall be in full force and effect with respect to theMust-Take Space as of the Advance Must-Take Effective Date, except that (a) theMust-Take Term shall be extended to include the period commencing upon theAdvance Must-Take Effective Date through and including December 31, 2010 (suchperiod being referred to herein as the “**Advance Must-Take Term**”),and (b) the Base Rent for the Must-Take Space during the Advance Must-Take Termshall be the then Prevailing Market rate for the Must-Take Space, as determinedin accordance with Subsection F below, as modified by this paragraph, providedthat there shall be no Minimum Initial Base Rent or Maximum Initial Base Rentfor such purposes. Landlord and Tenant acknowledge and agree that thedetermination of Base Rent for the Advance Must-Take Term is independent of andshall not affect in any way the determination of Base Rent for the remainder ofthe Must-Take Term, as set forth in Subsection F below. In the event that theTibco Sublease is in effect but Tenant has not yet taken possession of aportion of the Must-Take Space by the Advance Must-Take Effective Date, thenTenant shall take possession of such portion of the Must-Take Space, in itsthen as-is condition, immediately upon Landlord’s recovery of possessionthereof, and Tenant shall not be required to pay Rent with respect to suchportion until Landlord has so recovered possession.  Promptly following the Early TerminationDate, if any (regardless of whether such date is prior to April 1, 2010,notwithstanding Paragraph F.1 below), Landlord shall commence the procedure setforth in Subsection F below for determining the Prevailing Market rate for theMust-Take Space during the Advance Term.

F.                                      **Procedure for Determining Prevailing Market**.

1.                                       Noearlier than April 1, 2010, Landlord shall advise Tenant of the applicableInitial Base Rent for the Must-Take Space for the Must-Take Term (excludingBase Rent for the Advance Must-Take Term, if any).  Tenant, within 30 days thereafter, shalleither (i) give Landlord final binding written notice (“**Binding Notice**”) of Tenant’s acceptance of Landlord’sdetermination of the Initial Base Rent, or (ii) if Tenant disagrees withLandlord’s determination, provide Landlord with written notice of rejection(the “**Rejection Notice**”).  If Tenant fails to provide Landlord witheither a Binding Notice or Rejection Notice within such 30 day period, then theInitial Base Rent set forth in Landlord’s notice shall be deemed correct andshall be binding on Tenant.  If Tenantprovides Landlord with a Binding Notice (or fails to act within the 30 dayperiod provided above), Landlord and Tenant shall enter into the Must-TakeAmendment (as defined below) upon the terms and conditions set forthherein.  If Tenant provides Landlord witha Rejection Notice, Landlord and Tenant shall work together in good faith toagree upon the Prevailing Market rate. Upon agreement, Landlord and Tenant shall enter into the Must-TakeAmendment in accordance with the terms and conditions hereof.  Notwithstanding the foregoing, if Landlordand Tenant fail to agree upon the Prevailing Market rate within 30 days afterthe date Tenant provides Landlord with a Rejection Notice, Tenant, by writtennotice to Landlord (the “**Arbitration Notice**”)within 5 days after the expiration of such 30 day period, shall have the rightto have the Prevailing Market rate determined in accordance with the arbitrationprocedures described in Paragraph 2 below. If Landlord and Tenant fail to agreeupon the Prevailing Market rate within the 30 day period

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described and Tenant fails to timely exercise itsright to arbitrate, then the Initial Base Rent set forth in Landlord’s noticeshall be deemed correct and shall be binding on Tenant.

2.                                       ArbitrationProcedure.

(a)                                  IfTenant provides Landlord with an Arbitration Notice, Landlord and Tenant,within 10 days after the date of the Arbitration Notice, shall eachsimultaneously submit to the other, in a sealed envelope, its good faithestimate of the Prevailing Market rate (collectively referred to as the “**Estimates**”).  If thehigher of such Estimates is not more than 105% of the lower of such Estimates,then Prevailing Market rate shall be the average of the two Estimates.  If the Prevailing Market rate is not resolvedby the exchange of Estimates, then, within 10 days after the exchange ofEstimates, Landlord and Tenant shall each select an appraiser to determinewhich of the two Estimates most closely reflects the Prevailing Marketrate.  Each appraiser so selected shallbe certified as an MAI appraiser or as an ASA appraiser and shall have had atleast 5 years experience within the previous 10 years as a real estate appraiserworking in Palo Alto, California, with working knowledge of current rentalrates and practices.  For purposeshereof, an “MAI” appraiser means an individual who holds an MAI designationconferred by, and is an independent member of, the American Institute of RealEstate Appraisers (or its successor organization, or in the event there is nosuccessor organization, the organization and designation most similar), and an “ASA”appraiser means an individual who holds the Senior Member designation conferredby, and is an independent member of, the American Society of Appraisers (or itssuccessor organization, or, in the event there is no successor organization,the organization and designation most similar).

(b)                                 Uponselection, Landlord’s and Tenant’s appraisers shall work together in good faithto agree upon which of the two Estimates most closely reflects the PrevailingMarket rate.  The Estimate chosen by suchappraisers shall be binding on both Landlord and Tenant as the Initial BaseRent for the Must-Take Space during the first year****ofthe Must-Take Term, subject to the terms of clause (d) below regarding theMinimum Initial Base Rent and the Maximum Initial Base Rent, both as definedtherein*. ** ***If either Landlord orTenant fails to appoint an appraiser within the 10 day period referred toabove, the appraiser appointed by the other party shall be the sole appraiserfor the purposes hereof.  If the twoappraisers cannot agree upon which of the two Estimates most closely reflectsthe Prevailing Market rate within 20 days after their appointment, then, within10 days after the expiration of such 20 day period, the two appraisers shallselect a third appraiser meeting the aforementioned criteria.  Once the third appraiser (i.e. arbitrator)has been selected as provided for above, then, as soon thereafter aspracticable but in any case within 20 days, the arbitrator shall make hisdetermination of which of the two Estimates most closely reflects thePrevailing Market rate and such Estimate shall be binding on both Landlord andTenant as the Initial Base Rent rate for the Must-Take Space, subject to theterms of clause (d) below regarding the Minimum Initial Base Rent and theMaximum Initial Base Rent, both as defined therein. If the arbitrator believesthat expert advice would materially assist him, he may retain one or morequalified persons to provide such expert advice.  The parties shall share equally in the costsof the arbitrator and of any experts retained by the arbitrator.  Any fees of any appraiser, counsel or expertsengaged directly by Landlord or Tenant, however, shall be borne by the partyretaining such appraiser, counsel or expert.

(c)                                  Ifthe Prevailing Market rate (and accordingly the Initial Base Rent) has not beendetermined by the Must-Take Effective Date,

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Tenant shall commence payment of Base Rent for theMust-Take Space as of the Must-Take Effective Date at the baseline rate of$38.40 per rentable square foot per annum; provided that in the event of aMust-Take Advance Term Tenant shall instead commence payment of Base Rent equalto the Base Rent that Tenant would have paid during the Advance Must-Take Termpursuant to the Tibco Sublease had the Tibco Sublease remained in effect, untilsuch time as the Base Rent for the Advance Must-Take Term is determined.  Upon determination of the Initial Base Rent,the Initial Base Rent for the Must-Take Space shall be retroactively adjustedto the applicable effective date.  Ifsuch adjustment results in an underpayment of Base Rent by Tenant, Tenant shallpay Landlord the amount of such underpayment within 30 days after thedetermination thereof.  If suchadjustment results in an overpayment of Base Rent by Tenant, Landlord shallcredit such overpayment against the next installment of Base Rent due under theLease for the Must-Take Space and, to the extent necessary, any subsequentinstallments, until the entire amount of such overpayment has been creditedagainst Base Rent for the Must-Take Space.

(d)                                 Notwithstandinganything to the contrary contained herein, the parties agree that the InitialBase Rent for the Must-Take Space (except as provided herein with respect to anAdvance Must-Take Term) shall not be less than $30.72 per rentable square footper annum (the “**Minimum Initial Base Rent**”) andshall not be greater than $46.08 per rentable square foot per annum (the “**Maximum Initial Base Rent**”), regardless of any determinationof Prevailing Market rate made by the appraisers or arbitrator, as describedabove.

G.                                     Must-TakeAmendment.  Following thedetermination of the Initial Base Rent for the Must-Take Space (whether for theprimary Must-Take Term or for an Advance Must-Take Term), Landlord shallprepare an amendment (the “**Must-Take Amendment**”)to reflect the Base Rent, term and other appropriate terms for the Must-TakeSpace.  The Renewal Amendment shall besent to Tenant within a reasonable time after receipt of the Binding Notice andTenant shall execute and return the Renewal Amendment to Landlord within 15days after Tenant’s receipt of same, but, upon final determination of thePrevailing Market rate applicable during the Must-Take Term as describedherein, the Base Rent for the Must-Take Space shall be fully effective whetheror not the Must-Take Amendment is executed.

H.                                    PrevailingMarket.  For purposes of thisMust-Take provision, “**Prevailing Market**”shall mean the arms length fair market annual rental rate per rentable squarefoot under****new leases entered into on or aboutthe date on which the Prevailing Market is being determined hereunder for spacecomparable to the Premises in the Buildings and office buildings comparable tothe Building in the Palo Alto, California area. The determination of Prevailing Market shall take into account anymaterial economic differences between the terms of this Lease and anycomparison lease or amendment, such as rent abatements, construction costs(including the Must-Take Allowance) and other concessions and the manner, ifany, in which the landlord under any such lease is reimbursed for operatingexpenses and taxes.

II.**                                    Extension.**  The Term of the Lease is herebyextended for a period of 84 months and shall expire on September 30, 2014 (“**Extended Termination Date**”), unless sooner terminated inaccordance with the terms of the Lease. That portion of the Term commencing the day immediately following thePrior Termination Date (“**Extension Date**”)and ending on the Extended Termination Date shall be referred to herein as the “**Extended Term**”.

III.**                                Base Rent.** The Base Rent, Property Expenses and all other charges under the Lease,including the adjustments set forth in Paragraph 2 of the First Amendment,shall be payable as provided therein with respect to the Initial Premisesthrough and including the

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PriorTermination Date.  As of the ExtensionDate, the schedule of Base Rent payable with respect to the Initial Premisesduring the Extended Term is the following:
| Period                    | ** ** | **Annual Rate  Per Square Foot** | ** ** | **Monthly  Base Rent** | ** ** |
|---------------------------|------------|-------------------------------------------------|------------|-----------------------------|------------|
| 10/01/07 – 09/30/08  |       | $                                               | 31.80      |                        | $          | 142,649.50 |   |
| 10/01/08 – 09/30/09  |       | $                                               | 32.75      |                        | $          | 146,911.04 |   |
| 10/01/09 – 09/30/10  |       | $                                               | 33.74      |                        | $          | 151,352.02 |   |
| 10/01/10 – 09/30/11  |       | $                                               | 34.75      |                        | $          | 155,882.71 |   |
| 10/01/11 – 09/30/12  |       | $                                               | 35.79      |                        | $          | 160,547.98 |   |
| 10/01/12 – 09/30/13  |       | $                                               | 36.86      |                        | $          | 165,347.82 |   |
| 10/01/13 –  09/30/14 |       | $                                               | 37.97      |                        | $          | 170,327.09 |   |

 

Section 4(b) of the Lease andParagraph 2 of the First Amendment (CPI adjustments) shall be of no force oreffect during the Extended Term.  AllBase Rent during the Extended Term shall be payable by Tenant in accordancewith the terms of the Lease, as amended hereby.

IV.                                 **Security Deposit and Letter of Credit.**

A.                                   **Modifications to Lease.** Section 5 of the Original Lease is hereby amended to delete allreferences to a letter of credit, the parties hereto acknowledging that theprovisions of this Section IV shall govern any letter of credit (including theLetter of Credit defined below) obtained by Tenant for the benefit of Landlordin connection with the Lease, as amended hereby.  Landlord and Tenant acknowledge that allreferences in Section 5 of the Lease to an Additional Deposit are of no forceand effect, as pursuant to Paragraph 2 of the Second Amendment, the entireCurrent Security Deposit (defined in Paragraph D below) is the “SecurityDeposit” under the Lease.

B.                                     **Letter of Credit**.

1.                                      GeneralProvisions.  Simultaneously with Tenant’s execution and delivery of this FourthAmendment, Tenant shall deliver to Landlord, as collateral for the fullperformance by Tenant of all of its obligations under the Lease, as amendedhereby and from time to time hereafter, and for all losses and damages Landlordmay suffer as a result of Tenant’s default beyond applicable notice and cureperiods, including, but not limited to, any post lease termination damagesunder section 1951.2 of the California Civil Code, a standby, unconditional,irrevocable, transferable letter of credit (the “**Letter ofCredit**”), which Letter of Credit shall: (a) be in the amount of$1,135,000.00 (the “**LOC Amount**”);(b) be issued on the form attached hereto as **Exhibit D**;(c) name Landlord as its beneficiary; and (d) be drawn on an FDICinsured financial institution satisfactory to the Landlord.  The Letter of Credit (and any renewals orreplacements thereof) shall be for a term of not less than 1 year.  Tenant agrees that it shall from time totime, as necessary, whether as a result of adraw on the Letter of Credit by Landlord pursuant to the terms hereof or as aresult of the expiration of the Letter of Credit then in effect, renew orreplace the original and any subsequent Letter of Credit so that a Letter ofCredit, in the amount required hereunder, is continuously in effect until adate (the “**Final LOC Expiration Date**”) whichis at least 60 days after the Extended Termination Date of the Lease, as thesame may be further extended or renewed. If the Letter of Credit held by Landlord expires earlier than theFinal LOC Expiration Date (whether by reason of a stated expiration date or anotice of termination or non-renewal given by the issuing bank), Tenant shalldeliver a new Letter of Credit or certificate of renewal or extension (a “**Renewal or Replacement LOC**”) to Landlord not later than 60days prior to the expiration date of the Letter of Credit then held byLandlord.  Any Renewal or Replacement LOCshall comply with all of the provisions of this Section IV.B.

2.                                      Drawingsunder Letter of Credit. Landlord may, without prejudice to any other remedyprovided in the Lease or by law, draw on the Letter of Credit and use all orpart of the proceeds in accordance with the provisions of Section IV.B.3below.  In addition, if Tenant fails tofurnish a Renewal or Replacement LC complying with all of the provisions ofthis

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Section IV.B at least 60days prior to the stated expiration date of the Letter of Credit then held byLandlord, Landlord may draw upon such Letter of Credit and hold the proceedsthereof (and such proceeds need not be segregated) in accordance with the termsof this Section IV.B (the “**LOC Proceeds Account**”).

3.                                       Useof Proceeds by Landlord.  Subject tothe provisions of this Paragraph 3, the proceeds of the Letter of Credit shallconstitute Landlord’s sole and separate property (and not Tenant’s property orthe property of Tenant’s bankruptcy estate) and, following Tenant’s defaultunder the Lease, as amended hereby or as hereafter further amended, beyond anyapplicable notice and cure period, or as otherwise specifically agreed byLandlord and Tenant,  Landlord mayimmediately upon any draw (and without notice to Tenant, other than any noticeotherwise required under the Lease prior to an event of default) apply or offsetthe proceeds of the Letter of Credit: (a) against any Rent payable by Tenant under this Lease that is not paidwhen due; (b) against all losses and damages that Landlord has suffered or thatLandlord reasonably estimates that it may suffer as a result of Tenant’sfailure to comply with one or more provisions of this Lease, including anydamages arising under section 1951.2 of the California Civil Code followingtermination of the Lease; (c) against any costs incurred by Landlord inconnection with the Lease (including attorneys’ fees); and (d) against anyother amount that Landlord may spend or become obligated to spend by reason ofTenant’s default.  Provided Tenant is notthen in default of its obligations under the Lease, Landlord agrees to pay toTenant within 60 days after the Final LOC Expiration Date the amount of anyproceeds of the Letter of Credit received by Landlord and not applied asallowed above; provided, that if prior to the Final LOC Expiration Date avoluntary petition is filed by Tenant or any guarantor of the Lease (if any),or an involuntary petition is filed against Tenant or any guarantor of theLease (if any) by any of Tenant’s or such guarantor’s creditors, under theFederal Bankruptcy Code, then Landlord shall not be obligated to make suchpayment in the amount of the unused Letter of Credit proceeds until either allpreference issues relating to payments under this Lease have been resolved insuch bankruptcy or reorganization case or such bankruptcy or reorganizationcase has been dismissed, in each case pursuant to a final court order notsubject to appeal or any stay pending appeal.

4.                                       AdditionalCovenants of Tenant.  If, as resultof any application or use by Landlord of all or any part of the Letter ofCredit, the amount of the Letter of Credit shall be less than the Letter ofCredit Amount, Tenant shall, within 5 days thereafter, provide Landlord withadditional letter(s) of credit in an amount equal to the deficiency (or areplacement letter of credit in the total Letter of Credit Amount), and anysuch additional (or replacement) letter of credit shall comply with all of theprovisions of this Section IV.B, and if Tenant fails to comply with theforegoing, notwithstanding anything to the contrary contained in this Lease,the same shall constitute an incurable default by Tenant.  Tenant further covenants and warrants that itwill neither assign nor encumber the Letter of Credit or any part thereof andthat neither Landlord nor its successors or assigns will be bound by any such assignment,encumbrance, attempted assignment or attempted encumbrance.

5.                                       Natureof Letter of Credit.  Landlord andTenant (a) acknowledge and agree that in no event or circumstance shall theLetter of Credit or any renewal thereof or substitute therefor or any proceedsthereof (including the LOC Proceeds Account) be deemed to be or treated as a “securitydeposit” under any Law applicable to security deposits in the commercialcontext including Section 1950.7 of the California Civil Code, as such sectionnow exist or as may be hereafter amended or succeeded (“**SecurityDeposit Laws**”), (b) acknowledge and agree that the Letter of Credit(including any renewal thereof or substitute therefor or any proceeds thereof)is not intended to serve as a security deposit, and the Security Deposit Lawsshall have no applicability or relevancy thereto, and (c) waive any and allrights, duties and obligations either party may now or, in the future, willhave relating to or arising from the Security Deposit Laws. Tenant herebywaives the provisions of Section 1950.7 of

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the California Civil Codeand all other provisions of Law, now or hereafter in effect, which (i)establish the time frame by which Landlord must refund a security deposit undera lease, and/or (ii) provide that Landlord may claim from the security depositonly those sums reasonably necessary to remedy Defaults in the payment of rent,to repair damage caused by Tenant or to clean the Premises, it being agreedthat Landlord may, in addition, claim those sums specified above in thisSection IV.B.3.

6.                                       Application.  The provisions of this Section IV.B shallapply to the Letter of Credit or any Renewal or Replacement LOC notwithstandingany provisions to the contrary contained in the Lease.

C.                                     **Reductions in Letter of Credit. **Solong as Tenant under the Lease is the “Tenant” named in this Fourth Amendment,the LOC Amount may be reduced at the times and to the corresponding amountsspecified in Paragraphs 1 and  2 below onthe dates set forth therein (each a “**Reduction Date**”),if each of the following conditions is satisfied to Landlord’s satisfaction:  (i) Tenant is not and has not been in defaultunder the terms of the Lease beyond any applicable cure period****during the 36 month****periodpreceding the applicable Reduction Date, (ii) at the time of the applicableReduction Date, Tenant’s product known as Hematide is approved by the US Food& Drug Administration for medical use in humans, (iii) at the time of theapplicable Reduction Date, Hematide is generally available for prescription anddistribution through appropriate medical channels, and (iv) at the time of theapplicable Reduction Date, Tenant has Working Capital (as defined below) onhand in excess of (A) twenty-four (24), multiplied by (B) Tenant’s Average BurnRate (as defined below).  “**Working Capital**” shall be determined by Landlord in itsreasonable discretion and shall mean assets less intangible assets and totalliabilities, with intangible assets including nonmaterial benefits such asgoodwill, patents, copyrights, and trademarks. “**Average Burn Rate**” also shall bedetermined by Landlord in its reasonable discretion and shall mean (i) the sumof Tenant’s expenses for the previous 12 months, divided by (ii) twelve (12).Tenant shall deliver to Landlord for review Tenant’s financial statementsprepared in accordance with generally accepted accounting principles andaudited by a nationally recognized public accounting firm reasonably acceptableto Landlord, and any other financial information reasonably requested byLandlord in connection with Landlord’s determination of Working Capital andBurn Rate.

1.                                       Subjectto the foregoing, at any time after the end of the 61st month of the Extended Term, the LOC Amount maybe reduced to $1,010,000.00.

2.                                       Subjectto the foregoing, at any time after the end of the 73rd month of the Extended Term, the LOC Amount maybe reduced to $885,000.00.

D.                                    **Security Deposit.** Landlord and Tenant hereby acknowledge and agree that, in accordancewith the terms of Paragraph 5 of the Original Lease, Paragraph 1 of the SecondAmendment and Section I.A of the Third Amendment, Landlord currently holds acash security deposit (the “**Current Security Deposit**”)****from Tenant in the amount of $1,235,000.00, which asdescribed in the Second Amendment constitutes a single “Security Deposit” underthe Lease.  Provided that Tenant is notin default under the Lease, as amended hereby, as of the date Landlord hasreceived the Letter of Credit and Landlord and Tenant have fully executed anddelivered this Fourth Amendment, Landlord shall return****thethen unapplied portion of the Current Security Deposit to Tenant, less$50,000.00, within 45 days. Tenant acknowledges and agrees that Landlord willretain **$50,000.00** of the Current SecurityDeposit (the “**Remaining Security Deposit**”) to beheld by Landlord for the Extended Term, as the same may be further extended orrenewed, as an ongoing cash Security Deposit under the Lease, as amendedhereby, which shall be subject to the provisions governing the Security Depositset forth Paragraph 5 of the Original Lease, Paragraph 1 of the SecondAmendment and Section I.A of the Third Amendment.  Notwithstanding anything in the Lease to thecontrary, Tenant shall not have the right to convert the Remaining SecurityDeposit into a letter of credit.

V.                                     **Property Expenses.** For theperiod commencing with the Extension Date and ending on the ExtendedTermination Date, Tenant shall continue to pay for Property Expenses

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applicable to the Initial Premises in accordance with the terms of theLease, as amended hereby.

VI.                                 **Renewal Option.**

A.                                   Grantof Option; Conditions.  Tenant shallhave the right to extend the Extended Term (the “**RenewalOption**”) with respect to all of the Premises (as then defined underthe Lease) that are coterminous with the Initial Premises****forone additional period of 5 years commencing on the day following the ExtendedTermination Date and ending on the 5th anniversary of the Extended TerminationDate (the “**Renewal Term**”), if:

1.                                      Landlordreceives notice of exercise (“**Initial Renewal Notice**”)not less than 9 full calendar months prior to the expiration of the ExtendedTerm and not more than 15 full calendar months prior to the expiration of theExtended Term; and

2.                                      Tenantis not in default under the Lease beyond any applicable cure periods at thetime that Tenant delivers its Initial Renewal Notice or at the time Tenantdelivers its Binding Notice (as defined below); and

3.                                      Nopart of the Premises is sublet (other than pursuant to a Permitted Transfer, asdefined in Section 24 of the Lease, as amended by this Fourth Amendment) at thetime that Tenant delivers its Initial Renewal Notice or at the time Tenantdelivers its Binding Notice; and

4.                                      TheLease has not been assigned (other than pursuant to a Permitted Transfer, asdefined in Section 24 of the Lease, as amended by this Fourth Amendment) priorto the date that Tenant delivers its Initial Renewal Notice or prior to thedate Tenant delivers its Binding Notice.

B.                                     TermsApplicable to Premises During Renewal Term.

1.                                      Theinitial Base Rent rate per rentable square foot for the Premises during theRenewal Term shall equal the Prevailing Market (hereinafter defined) rate perrentable square foot for the Premises.  Base Rent during the Renewal Term shall increase,if at all, in accordance with the increases assumed in the determination ofPrevailing Market rate.  Base Rentattributable to the Premises shall be payable in monthly installments inaccordance with the terms and conditions of Section 4 of the Lease, as amendedhereby.

2.                                      Tenant shall pay Property Expenses for thePremises during the Renewal Term in accordance with Sections 4 and 6 ofthe Lease, as amended hereby, and the manner and method in which Tenantreimburses Landlord for Tenant’s share of Property Expenses shall be some ofthe factors considered in determining the Prevailing Market rate for theRenewal Term.

C.                                     Procedurefor Determining Prevailing Market. Within 30 days after receipt of Tenant’s Initial Renewal Notice,Landlord shall advise Tenant of the applicable Base Rent rate for the Premisesfor the Renewal Term.  Tenant, within 15days after the date on which Landlord advises Tenant of the applicable BaseRent rate for the Renewal Term, shall either (i) give Landlord finalbinding written notice (“**Binding Notice**”)of Tenant’s exercise of its Renewal Option, or (ii) if Tenant disagreeswith Landlord’s determination, provide Landlord with written notice ofrejection (the “**Rejection Notice**”).  If Tenant fails to provide Landlord witheither a Binding Notice or Rejection Notice within such 15 day period, Tenant’sRenewal Option shall be null and void and of no further force and effect.  If Tenant provides Landlord with a BindingNotice, Landlord and Tenant shall enter into the Renewal Amendment (as definedbelow) upon the terms and conditions set forth herein.  If Tenant provides Landlord with a RejectionNotice, Landlord and Tenant shall work together in good faith to agree upon thePrevailing Market rate for the Premises during the Renewal Term.  Upon agreement, Tenant shall provide Landlordwith Binding Notice and Landlord and Tenant shall enter into the RenewalAmendment in accordance with the terms and conditions hereof.  Notwithstanding the foregoing, if Landlord andTenant fail to agree upon the Prevailing Market rate within 30 days after thedate Tenant provides Landlord

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with the Rejection Notice, Tenant, by written noticeto Landlord (the “**Arbitration Notice**”)within 10 days after the expiration of such 30 day period, shall have the rightto have the Prevailing Market rate determined in accordance with thearbitration procedures described in Subsection D below.  If Landlord and Tenant fail to agree upon thePrevailing Market rate within the 30 day period described and Tenant fails totimely exercise its right to arbitrate, Tenant’s Renewal Option shall be deemedto be null and void and of no further force and effect.

D.                                    ArbitrationProcedure.

1.                                      IfTenant provides Landlord with an Arbitration Notice, Landlord and Tenant,within 10 days after the date of the Arbitration Notice, shall eachsimultaneously submit to the other, in a sealed envelope, its good faithestimate of the Prevailing Market rate for the Premises during the Renewal Term(collectively referred to as the “**Estimates**”).  If the higher of such Estimates is not morethan 105% of the lower of such Estimates, then Prevailing Market rate shall bethe average of the two Estimates.  If thePrevailing Market rate is not resolved by the exchange of Estimates, then,within 10 days after the exchange of Estimates, Landlord and Tenant shall eachselect an appraiser to determine which of the two Estimates most closelyreflects the Prevailing Market rate for the Premises during the RenewalTerm.  Each appraiser so selected shallbe certified as an MAI appraiser or as an ASA appraiser and shall have had atleast 5 years experience within the previous 10 years as a real estateappraiser working in Palo Alto, California, with working knowledge of currentrental rates and practices.  For purposeshereof, an “MAI” appraiser means an individual who holds an MAI designationconferred by, and is an independent member of, the American Institute of RealEstate Appraisers (or its successor organization, or in the event there is nosuccessor organization, the organization and designation most similar), and an “ASA”appraiser means an individual who holds the Senior Member designation conferredby, and is an independent member of, the American Society of Appraisers (or itssuccessor organization, or, in the event there is no successor organization,the organization and designation most similar).

2.                                      Uponselection, Landlord’s and Tenant’s appraisers shall work together in good faithto agree upon which of the two Estimates most closely reflects the PrevailingMarket rate for the Premises.  TheEstimate chosen by such appraisers shall be binding on both Landlord and Tenantas the Base Rent rate for the Premises during the Renewal Term*. ** ***Ifeither Landlord or Tenant fails to appoint an appraiser within the 10 dayperiod referred to above, the appraiser appointed by the other party shall bethe sole appraiser for the purposes hereof. If the two appraisers cannot agree upon which of the two Estimates mostclosely reflects the Prevailing Market within 30 days after their appointment,then, within 10 days after the expiration of such 30 day period, the twoappraisers shall select a third appraiser meeting the aforementionedcriteria.  Once the third appraiser (i.e.arbitrator) has been selected as provided for above, then, as soon thereafteras practicable but in any case within 20 days, the arbitrator shall make hisdetermination of which of the two Estimates most closely reflects thePrevailing Market rate and such Estimate shall be binding on both Landlord andTenant as the Base Rent rate for the Premises. If the arbitrator believes that expert advice would materially assisthim, he may retain one or more qualified persons to provide such expertadvice.  The parties shall share equallyin the costs of the arbitrator and of any experts retained by thearbitrator.  Any fees of any appraiser,counsel or experts engaged directly by Landlord or Tenant, however, shall beborne by the party retaining such appraiser, counsel or expert.

3.                                      Ifthe Prevailing Market rate has not been determined by the commencement date ofthe Renewal Term, Tenant shall pay Base Rent upon the terms and conditions ineffect during the last month of the initial Term for the Premises until suchtime as the Prevailing Market rate has been determined.  Upon such determination, the Base Rent forthe Premises shall be retroactively adjusted to the commencement of the

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Renewal Term for the Premises.  If such adjustment results in an underpaymentof Base Rent by Tenant, Tenant shall pay Landlord the amount of such underpaymentwithin 30 days after the determination thereof. If such adjustment results in an overpayment of Base Rent by Tenant,Landlord shall credit such overpayment against the next installment of BaseRent due under the Lease and, to the extent necessary, any subsequentinstallments, until the entire amount of such overpayment has been creditedagainst Base Rent.

E.                                      RenewalAmendment.  If Tenant is entitled toand properly exercises its Renewal Option, Landlord shall prepare an amendment(the “**Renewal Amendment**”) to reflect changesin the Base Rent, Term, Termination Date and other appropriate terms.  The Renewal Amendment shall be sent to Tenantwithin a reasonable time after receipt of the Binding Notice and Tenant shall executeand return the Renewal Amendment to Landlord within 15 days after Tenant’sreceipt of same, but, upon final determination of the Prevailing Market rateapplicable during the Renewal Term as described herein, an otherwise validexercise of the Renewal Option shall be fully effective whether or not theRenewal Amendment is executed.

F.                                      Definitionof Prevailing Market.  For purposesof this Renewal Option, “**Prevailing Market**”shall mean the arms length fair market annual rental rate per rentable squarefoot under renewal leases and amendments entered into on or about the date onwhich the Prevailing Market is being determined hereunder for space comparableto the Premises in the Building and office buildings comparable to the Buildingin the Palo Alto, California area.  Thedetermination of Prevailing Market shall take into account any materialeconomic differences between the terms of this Lease and any comparison leaseor amendment, such as rent abatements, construction costs and other concessionsand the manner, if any, in which the landlord under any such lease isreimbursed for operating expenses and taxes.  The determination of Prevailing Market shall also take intoconsideration any reasonably anticipated changes in the Prevailing Market ratefrom the time such Prevailing Market rate is being determined and the time suchPrevailing Market rate will become effective under this Lease.

VII.                             **Rights of First Offer.**

A.                                   Grantof Option; Conditions.  Tenant shallhave the one time right of first offer (each a “**Right ofFirst Offer**”) with respect to each of the following spaces, as moreparticularly shown on **Exhibits E-1 - E-8**,respectively****(each an “**OfferingSpace**”):

1.                                      Approximately41,504 rentable square feet in the 4005 Miranda Building known as Suite 100,currently leased to Tibco pursuant to the Existing Lease (both as defined inRecital B), which is scheduled to expire by its terms on December 31, 2010,subject to one (1) renewal option for an additional five (5) year term;

2.                                      Approximately5,988 rentable square feet in the 4005 Miranda Building known as Suite 150, thecurrent lease for which is scheduled to expire on December 31, 2009;

3.                                      Approximately1,825 rentable square feet in the 4005 Miranda Building known as Suite 160, thecurrent lease for which is scheduled to expire on December 31, 2009;

4.                                      Approximately4,513 rentable square feet in the 4005 Miranda Building known as Suite 175, thecurrent lease for which is scheduled to expire on April 30, 2007, subject toone (1) renewal option for an additional one (1) year term;

5.                                      Approximately24,541 rentable square feet in the 4009 Miranda Building known as Suite 100,currently leased to Tibco pursuant to the Existing Lease, which is scheduled toexpire by its terms on December 31, 2010, subject to one (1) renewal option foran additional five (5) year term;

6.                                      Approximately15,826 rentable square feet in the 4009 Miranda Building

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known as Suite 200 (“**4009/200**”),the current lease for which is scheduled to expire on October 30, 2010;

7.                                      Approximately6,015 rentable square feet in the 4009 Miranda Building known as Suite 225 (“**4009/225**”), the current lease for which is scheduled toexpire on June 30, 2009, subject to one (1) renewal option for an additionalfive (5) year term;

8.                                      Approximately7,448 rentable square feet in the 4009 Miranda Building known as Suite 250 (“**4009/250**”), the current lease for which is scheduled toexpire on June 30, 2009, subject to one (1) renewal option for an additionalfive (5) year term.

Each currently scheduled expiration date listed aboveis referred to herein as a “**Scheduled Expiration Date**”;provided that if an existing tenant in an Offering Space exercises a currentlyexisting renewal option listed above, the “Scheduled Expiration Date” for thatOffering Space shall instead mean the expiration date as so extended.

Tenant’s Right of First Offer shall be exercised withrespect to each Offering Space as follows: Landlord shall advise Tenant (the “**Advice**”), no later than 120 days prior to the ScheduledExpiration Date for the applicable Offering Space, but prior to leasing suchOffering Space to a third party, of the size and location of the applicableOffering Space and the terms under which Landlord is prepared to lease suchOffering Space to Tenant, which terms shall reflect the Prevailing Market(hereinafter defined) rate for such Offering Space as reasonably determined byLandlord.  Tenant may lease such OfferingSpace in its entirety only, under such terms, by delivering written notice ofexercise to Landlord (the “**Notice of Exercise**”)within 10 days after the date of the Advice, except that Tenant shall have nosuch Right of First Offer and Landlord need not provide Tenant with an Advice,if:

a.                                       Tenantis in default under the Lease beyond any applicable cure periods at the timethat Landlord would otherwise deliver the Advice; or

b.                                      morethan fifty-five percent (55%) of the rentable square footage of the Premises issublet (other than pursuant to a Permitted Transfer, as defined in Section 24of the Lease, as amended by this Fourth Amendment) at the time Landlord wouldotherwise deliver the Advice; or

c.                                       theLease has been assigned (other than pursuant to a Permitted Transfer, asdefined in Section 24 of the Lease, as amended by this Fourth Amendment) priorto the date Landlord would otherwise deliver the Advice; or

d.                                      theOffering Space is not intended for the exclusive use of Tenant, and/or of anytransferee of a Permitted Transfer, during the Term.

B.                                     Termsfor Offering Space.

1.                                      Theterm for the applicable Offering Space shall commence upon the commencementdate stated in the Advice and thereupon such Offering Space shall be considereda part of the Premises, provided that all of the terms stated in the Advice,including the term applicable to the Offering Space, shall govern Tenant’sleasing of such Offering Space and only to the extent that they do not conflictwith the Advice, the terms and conditions of this Lease, as amended hereby,shall apply to such Offering Space.

2.                                      Tenantshall pay Base Rent and Additional Rent for the applicable Offering Space inaccordance with the terms and conditions of the Advice, which terms andconditions shall reflect the Prevailing Market rate for such Offering Space asdetermined in Landlord’s reasonable judgment.

3.                                      Theapplicable Offering Space (including improvements and personalty, if any) shallbe accepted by Tenant in its “as-is” condition and as-built

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configuration existing on the earlier of the dateTenant takes possession of such Offering Space or as of the date the term forsuch Offering Space commences, unless the Advice specifies any work to beperformed by Landlord in such Offering Space, in which case Landlord shallperform such work in such Offering Space. If Landlord is delayed delivering possession of the applicable OfferingSpace due to the holdover or unlawful possession of such space by any party,Landlord shall use reasonable efforts to obtain possession of the space, andthe commencement of the term for such Offering Space shall be postponed untilthe date Landlord delivers possession of such Offering Space to Tenant freefrom occupancy by any party.

C.                                     Terminationof Right of First Offer.  The rightsof Tenant hereunder with respect to the Offering Space shall terminate on theearlier to occur of: (i) September 30, 2013; (ii) with respect to anyparticular Offering Space, Tenant’s failure to exercise its Right of FirstOffer with respect to such space within the 10 day period provided inSection A above; and (iii) with respect to any particular OfferingSpace, the date Landlord would have provided Tenant an Advice for such space ifTenant had not been in violation of one or more of the conditions set forth inSection A above.

D.                                    OfferingAmendment.  If Tenant exercises itsRight of First Offer, Landlord shall prepare an amendment (the “**Offering Amendment**”) adding the applicable Offering Space tothe Premises on the terms set forth in the Advice and reflecting the changes inthe Base Rent, Security Deposit, Rentable Square Footage of the Premises,Tenant’s Pro Rata Share and/or Percentage Share and other appropriateterms.  A copy of the Offering Amendmentshall be sent to Tenant within a reasonable time after Landlord’s receipt ofthe Notice of Exercise executed by Tenant, and Tenant shall execute and returnthe Offering Amendment to Landlord within 30 days thereafter, but an otherwisevalid exercise of the Right of First Offer shall be fully effective whether ornot the Offering Amendment is executed.

E.                                      Definitionof Prevailing Market.  For purposesof this Right of First Offer provision, “**Prevailing Market**”shall mean the annual rental rate per square foot for space comparable to theOffering Space in the building in which the Offering Space is located andoffice buildings comparable to the applicable building in the Palo Alto,California area under leases and renewal and expansion amendments being enteredinto at or about the time that Prevailing Market is being determined, givingappropriate consideration to tenant concessions, brokerage commissions, tenantimprovement allowances, existing improvements in the space in question, and themethod of allocating operating expenses and taxes.

F.                                      Subordination.Notwithstanding anything herein to the contrary, Tenant’s Right of First Offerfor 4009/200 is subject and subordinate to the right of first offer of thecurrent tenant of 4009/225 and 4009/250 as set forth in such tenant’s lease asof the date of this Amendment.

G.                                     EarlyAvailability.  If any existing leaseset forth in Section A is terminated and Landlord regains possession of theapplicable Offering Space prior to the Scheduled Expiration Date for suchspace, then notwithstanding Subsection A above, the period for Landlord’sdelivery of an Advice for such Offering Space shall instead be no later than 90days following Landlord’s recovery of possession.

VIII.**                         Other Miscellaneous Provisions.**  Landlordand Tenant agree that, effective as of the date of this Fourth Amendment(unless different effective date(s) is/are specifically referenced in thisSection), the Lease shall be amended in the following additional respects:

A.                                   **Deletions**.  Each ofthe following provisions is hereby deleted from the Lease in its entirety andshall be of no further force or effect: Sections 2 (Option to Extend) (as confirmed in Paragraph 3 of the FirstAmendment), 35.1 (Right of First Offer to Lease), Section 35.2 (Second Right ofOffer and Refusal for Sale), 37 (Move-In Bonus) and 51 (Conditions) of theOriginal Lease.  Tenant acknowledges thatLandlord has no further obligations to Tenant under the Work Letter attached as**Exhibit C** to the Lease to constructLandlord Work or to disburse any portion of

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theTenant Improvements Allowance or Additional Allowance (all as defined therein),and that the Work Letter has no application to the Must-Take Work Letter orInitial Premises Work Letter except to the extent that Paragraph 13 of the WorkLetter is specifically incorporated therein.

B.                                     **Definitions and General LeaseModifications. **Landlord and Tenant acknowledge and agree that****for purposes of the Lease and for this Fourth Amendment,****the term “**Complex**” shallmean the entire Foothill Research Center, including the “Complex” as defined inthe Original Lease, consisting of the 4001 Miranda Building, the 4005 MirandaBuilding and the 4009 Miranda Building, and the 4015 Miranda Building and theseparate legal parcel on which it is located. Accordingly “**Tenant’s Percentage**”for the Initial Premises is hereby amended from 33.33% to **28.0189%**,reflecting a total rentable square footage****for theComplex of 192,120.** **The term “**Common Areas**”shall include the common areas serving the entire Complex, as defined in thisParagraph B, including any Common Areas in the vicinity of the 4015 MirandaBuilding that may not be shown on **Exhibit A** tothe Original Lease.  With respect only toMulti-Tenant Buildings (as defined below), “Common Areas” also shall mean thecommon areas inside the applicable building, such as lobbies, corridors andcommon area restrooms. “**Building”**shallmean the building in the Complex in which the applicable portion of the Premisesis located.  If Tenant leases any spacein the Complex in a building in which Tenant does not lease the entireBuilding, pursuant to a Right of First Offer of otherwise, such Building shallbe referred to herein as a****“**Multi-Tenant Building**”. No representations by Landlord set forth in the Original Lease withrespect to the Initial Premises shall be deemed remade in connection with theMust-Take Space or any Offering Space, unless specifically provided for herein.

C.                                     **Landlord’s Address for Notices and Payment of Rent**.Notwithstanding anything to the contrary contained in the Lease, Landlord’saddress for notices and payment of Rent set forth in Section 4(d) of theOriginal Lease is hereby deleted in its entirety and replaced with thefollowing:
| “Landlord:                                                                                                                                                     | With  a copy to:                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                |                                                                                                               |
| CA-Foothill Research Center  Limited Partnership  c/o Equity Office  950 Tower Lane, Suite 950  Foster City, California 94404  Attention: Foothill Property Manager | Equity Office  One Market Street  Spear Tower, Suite 600  San Francisco, CA 94105  Attn: San Jose Regional Counsel |

 

All payments of Rent shall be payable to the entity, and sent to theaddress, Landlord designates from time to time in writing.”

D.                                 **Property Expenses**.

1.                                      Section6 is hereby amended to provide that with respect to any Multi-Tenant Building,in the case of Property Expenses for which Tenant is 100% responsible in theInitial Premises but which are common to all tenants of the applicableMulti-Tenant Building (for example, replacement of the roof membrane asprovided in Section I below, subject to the limitations provided in the Lease)or costs arising out of Landlord’s repair and maintenance obligationsapplicable only to Multi-Tenant Buildings (also as set forth in Section Ibelow), Tenant shall be responsible only for Tenant’s Pro Rata Share (asdefined in Paragraph 2 below) of such costs. Such costs shall be included in Property Expenses for the applicableBuilding and Tenant shall pay Tenant’s Pro Rata Share of such Building-specificexpenses in accordance with the procedures set forth in Section 47 of theLease, as amended hereby.

2.                                      Tenant’s“**Pro Rata Share**” of any particularMulti-Tenant Building shall be a percentage calculated by dividing the rentablesquare footage of the portion of the Premises located in such Building by thetotal rentable square footage of the Building and multiplying the quotient by100.

3.                                      Withrespect to any Multi-Tenant Building, “**Tenant’s Percentage**”shall be Tenant’s Pro Rata Share of the applicable Building’s pro rata share of

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the rentable squarefootage of the Complex.  For example, the4005 Miranda Building’s pro rata share of the Complex is 28.0189%, so if tenantwere to lease space (less than the entire Building) in the 4015 MirandaBuilding, Tenant’s Percentage Share applicable to such space would be equal to28.0189%, multiplied by Tenant’s Pro Rata Share of the 4005 Miranda Building,divided by 100.

4.                                      Withrespect to any Multi-Tenant Building, (a) clause (iii) of Section 6(a)(i) shallnot apply, and any reasonable costs so incurred by Landlord shall be includedin Real Property Taxes, and (b) Section 6(a)(ii) shall not apply.

5.                                      Thefollowing is hereby added to the end of the 8th sentence of Section 6(b): “, as the same maybe amended from time to time.”

6.                                      Withrespect to Multi-Tenant Buildings, (a) the “Common Areas” (and associated “CommonArea Expenses”, as set forth in Section 6(e)) shall include the Common Areaswithin the building, (b) the provisions of Section 6(d) requiring that allutilities to the Premises be separately metered shall not apply, and Landlordshall provide utilities reasonably determined by Landlord to be standard forthe applicable building and shall include the cost thereof in PropertyExpenses, and (c) the following shall be added to the end of the last sentenceof Section 6(f): “, except that Tenant shall pay Tenant’s Pro Rata Share of100% of such expenses incurred with respect to Common Areas located in theinterior of an applicable Multi-Tenant Building.”

7.                                      Thefollowing is added to the end of Section 6(g)(2) and Section 6(g)(11): “otherthan deductibles under insurance carried by Landlord pursuant to this Lease”.

8.                                      Thefollowing is added to the end of Section 6(g)(4): “unless such defects are theresult of work performed by Tenant or any previous tenant in the Premises.”

E.                                      **Use. **The7th sentenceof****Section 7 of the Lease shall not applyto any portion of the Premises in a Multi-Tenant Building.  The 3rd sentence of Section 7 of the OriginalLease shall not apply to the Must-Take Space or any Offering Space.  Tenant acknowledges that the Ground Leaseimposes a fee on certain office uses in the Complex.  Landlord agrees to cooperate with Tenant inobtaining the agreement of Ground Lessor that such fee shall not apply toTenant’s proposed office uses in the Must-Take Space (and, in the event thatTenant leases any Offering Space, at the time Tenant seeks Ground Lessor’sconsent to such expansion, in such Offering Space); provided that if GroundLessor’s agreement is conditioned upon Tenant’s office uses being ancillary toTenant’s ongoing research and development uses the Complex, then if GroundLessor later imposes an office use fee due to Tenant’s failure to meet theconditions set forth in Ground Lessor’s consent, Tenant shall be solelyresponsible for payment of such use fee.

F.**                                      Notices**.  Without limiting theprovisions of Paragraph 8 of the Original Lease, notices may also besent by overnight or same day courier service to the parties at theirrespective addresses set forth in the Lease, as amended hereby, and each noticegiven in such manner shall be deemed to have been received on the earlier tooccur of actual delivery or the date on which delivery is refused, or, ifTenant has vacated the Premises or any other notice address of Tenant withoutproviding a new notice address, 3 days after notice is deposited with a courierservice in the manner described above.

G.                                     **Condition of Premises**. The first two sentences of Section 11 of the Lease shall not apply tothe Must-Take Space or to any Offering Space.

H.                                    **Alterations**.

1.                                       The5th sentence of Section 12.A is hereby amended toreplace “Fifteen Thousand and no/100ths Dollars” with “Twenty-Five Thousand andno/100ths Dollars.”  The last sentence ofSection 12.A is hereby deleted.

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2.                                      Withrespect to any Alterations made in a Multi-Tenant Building, the 5th sentence of Section 12.A shall not apply andthe following language shall apply in lieu thereof:

“However, Landlord’sconsent shall not be required for any Alteration that satisfies all of thefollowing criteria (a “**Cosmetic Alteration**”):  (a) is of a cosmetic nature such aspainting, wallpapering, hanging pictures and installing carpeting; (b) isnot visible from the exterior of the Premises or Building; (c) will notaffect the base building systems; and (d) does not require work to beperformed inside the walls or above the ceiling of the Premises. CosmeticAlterations shall be subject to all the other provisions of thisSection 12.A.”

3.                                      Thelast sentence of Section 12.B of the Lease is hereby amended to replace “AdditionalDeposit” with “Security Deposit or proceeds of the Letter of Credit”.

4.                                      Asprovided in the Initial Premises Work Letter and the Must-Take Work Letter,Section 12.B of the Lease shall apply generally to the Initial PremisesAlterations and the Must-Take Alterations even though the nature of suchimprovements is not yet determined; provided that in determining categories ofsuch improvements for purposes of Section 12.B, Landlord shall not be requiredto designate any improvements that are Nonremovable Tenant Improvements as “LeaseableNonremovable Tenant Improvements” (and accordingly will not be required towaive its interest in or subordinate Landlord’s claim to any such improvementsor equipment for the benefit of Tenant’s lenders or equipment lessors) if suchimprovements are paid for in whole or in part by the Initial Premises Allowanceor the Must-Take Allowance.

I.                                         **Repairs and Maintenance.**

1.                                      Withrespect only to portions of the Premises located in a Multi-Tenant Building,the following are added to Section 13(a): “(f) mechanical (including HVAC),electrical, plumbing, elevators and fire/life safety systems serving theBuilding in general (as opposed to exclusively serving the Premises), and (g)Common Areas located inside the Building.”  The cost of such additional items shall be Property Expenses chargeableto Tenant in accordance with the provisions of the first three sentences of thesecond paragraph of Section 13(a).

2.                                      Theportion of the 5th sentence of Section 13(a) prior to theparenthetical is hereby deleted and replaced with “If at any time the roofmembrane of a Building in which a portion of the Premises is located requiresreplacement in part or whole as a result of wear and tear”.

3.                                      The4th, 5th and 6th sentences of the second paragraph of Section13(a) shall not apply to any Multi-Tenant Building.

4.                                      Withrespect to any portion of the Premises other than the Initial Premises, the 3rdand 4th sentences of Section 13(b)(i) shall apply only to latent defects in theoriginal construction of the applicable building or to work actually performedby Landlord (as opposed to work performed by Tenant or any previous tenant inthe applicable Premises).

5.                                      Section 13(b)(ii) shall not interpreted torequire Tenant to maintain or repair plumbing, electrical, HVAC or mechanicalsystems that are Landlord’s maintenance responsibility pursuant to SectionVIII.I.1 above in any portion of the Premises located in a Multi-TenantBuilding.

J.                                        **Damage to Tenant’s Property.** The first sentence of Section 17 of the Lease is hereby amended to addthe words “or which are otherwise beyond the reasonable control of Landlord”following “or any other cause whatsoever,” and to add the words “(unless suchdefects are the result of work performed by Tenant or any previous tenant inthe Premises)” at the end of such sentence.

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K.                                    **Liability Insurance. **The6th sentence of Section 19 shall not apply to anyportion of the Premises located in a Multi-Tenant Building.

L.                                      **Other Insurance to be Maintained by Tenant.**  Section 20 of the Lease is hereby amended toprovide that Tenant’s sprinkler leakage endorsement shall include coverage forearthquake sprinkler leakage.

M.                                 **Damage or Destruction.**

1.                                      Inthe second sentence of 21(a) of the Lease, the word “Building” is herebyreplaced with “applicable Building or Buildings”.

2.                                      Thefourth sentence of Section 21(a) of the Lease is hereby deleted and replacedwith the following:

“If damage to the Premises in any particularBuilding(s) exceeds eighty percent (80%) of the replacement value of theportion of the Premises located in the applicable Building(s) (includingexcavation and foundation), and the estimated time of reconstruction of theportion of the Premises in the applicable Building(s) exceeds eighteen (18)months, Landlord shall have the right to terminate the Lease with respect tothe portion of the Premises located in the applicable Building(s) upon writtennotice to Tenant.  If Landlord elects toterminate the Lease pursuant to the foregoing with respect to a portion, butnot all, of the Premises, then Tenant, within 30 days following Landlord’snotice of such termination, may elect to terminate the Lease with respect tothe remainder of the Premises; provided that such termination right shall beconditioned on Tenant’s determination, in its reasonable judgment and as setforth in a representation in Tenant’s termination notice, that Tenant cannotmove its operations that were located in the affected Premises into anotherportion of the Premises using commercially reasonable efforts for a total costto Tenant that is less than the cost Tenant would reasonably incur to move itsentire operation out of the Complex to another location.  Tenant’s termination of the Lease withrespect to the remaining Premises shall be effective as of the date specifiedby Tenant in its notice, but no later than 90 days following Landlord’s noticeof termination. Notwithstanding the foregoing, if Tenant elects to terminatethe Lease with respect to the entire Premises pursuant to the foregoing,Landlord shall have the option to withdraw its notice of termination withrespect to the portion of the Premises within 30 days following receipt ofTenant’s notice, in which event the Lease shall continue in full force and effectand Landlord shall reconstruct the damaged portion of the Premises inaccordance with this Section 21(a).”

3.                                      Thesixth sentence of Section 21(a) of the Lease is hereby deleted and replacedwith the following:

“If the estimated time of reconstruction of theportion of the Premises located in any particular Building(s) (including forthese purposes the parking areas benefiting such portion of the Premises,unless Landlord provides reasonable alternative parking to Tenant (e.g. valetparking)) exceeds eighteen (18) months and the damage to the affected portionof the Premises has a material adverse effect on Tenant’s operations in theportion of the Premises located in the applicable Building(s), Tenant shallhave the right to terminate the Lease with respect to the portion of thePremises located in the applicable Building(s) upon written notice to Landlorddelivered within 30 days following Landlord’s notice.  In addition, if Tenant has the right topartially terminate the Lease pursuant to the foregoing, then Tenant may electto terminate the Lease with respect to the remainder of the Premises; providedthat such additional termination right shall be conditioned on Tenant’sdetermination, in its reasonable judgment and as set forth in a representationin Tenant’s termination notice, that Tenant cannot move its operations thatwere located in the affected Premises into another portion of the Premisesusing commercially reasonable efforts for a total cost to Tenant that is lessthan the cost Tenant would reasonably incur to move its entire operation out ofthe Complex to another location.  Tenant’stermination of the Lease with

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respect to the remaining Premises shall be effectiveas of the date specified by Tenant in its notice, but no later than 90 days followingTenant’s notice.”

N.                                    **Eminent Domain.**

1.                                      Forpurposes of Section 22(a), the phrase “substantially interfere with Tenant’suse and occupancy thereof” shall mean that the loss of the use of the portiontaken shall materially and adversely affect Tenant’s operation of its businesswithin the entire Premises.  A partialtaking shall not be deemed to “substantially interfere with Tenant’s use andoccupancy thereof” if Tenant’s uses can be relocated within the overallPremises in a commercially reasonable manner.

2.                                      InSection 22(a):

(a)                                  Thefollowing is added to the end of clause (ii) of the 3rd sentence: “, amortized over the initial Term”.

(a)                                  Thewords “the fair market rental value of the Premises (as defined by paragraph2(c)” in the 4th sentence are replaced by “the PrevailingMarket value (as defined in the Renewal Option set forth in the FourthAmendment)”.

(b)                                 Effectiveas of the Extension Date, the words “assuming a CPI increase of five percent(5%) per year” in the 4th sentence are hereby deleted.

(c)                                  Theprovisions of clause (iv) of the 3rd sentence and the entirety of the 4th and 5th sentences shall not apply to any portion ofthe Premises in a Multi-Tenant Building.

5.                                      Thefollowing is added to the end of the first sentence of Section 22(d) of theLease: “or other reasonable alternative parking (e.g. valet parking).”

6.                                      Tenanthereby waives any and all rights under and benefits of Section 1265.130 ofthe California Code of Civil Procedure, or any similar or successor laws now orhereinafter in effect, it being understood that Section 22 of the Lease shallgovern the rights and obligations of Landlord and Tenant in the event ofcondemnation or eminent domain.

O.                                    **Defaults and Remedies.**

1.                                      Thefirst sentence of Section 23(a) is hereby deleted and replaced with thefollowing: “The abandonment of all of the Premises, or of any portion of thePremises that constitutes all of the Premises located in any particularBuilding.”  The word  “applicable” is added prior to the word “Premises”in the next sentence.

2.                                      Section23(c) is hereby amended to add “Tenant acknowledges that this provision isintended to grant Landlord the remedy found in Section 1951.4 of the CaliforniaCivil Code.”

3.                                      Thefollowing is hereby added to the end of Section 23(e): “Payments of PropertyExpenses shall constitute “Rent” under the Lease.

4.                                      TENANTHEREBY WAIVES ANY AND ALL RIGHTS CONFERRED BY SECTION 3275 OF THE CIVILCODE OF CALIFORNIA AND BY SECTIONS 1174 (c) AND 1179 OF THE CODE OF CIVILPROCEDURE OF CALIFORNIA AND ANY AND ALL OTHER LAWS AND RULES OF LAW FROM TIMETO TIME IN EFFECT DURING THE TERM OF THE LEASE AS AMENDED HEREBY, PROVIDINGTHAT TENANT SHALL HAVE ANY RIGHT TO REDEEM, REINSTATE OR RESTORE THE LEASEFOLLOWING ITS TERMINATION BY REASON OF TENANT’S BREACH.  TENANT ALSO HEREBY WAIVES, TO THE FULLESTEXTENT PERMITTED BY LAW, THE RIGHT TO TRIAL BY JURY IN

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ANY LITIGATION ARISING OUT OF OR RELATING TO THELEASE, AS HEREBY AMENDED.

P.                                      **Assignment and Subletting**.

1.                                      [Intentionally Omitted]

2.                                      The fourth sentence of Section 24 of the Lease ishereby deleted and replaced with:  “Landlordshall respond to Tenant’s request for consent within 10 business days.  If Landlord fails to respond within such 10business day period, then Tenant may deliver a second request to Landlord statingthat if Landlord does not respond within 5 days after the second request,landlord’s consent shall be deemed given, and, if Landlord fails to respondwithin 5 days after delivery of such second notice, Landlord’s consent shall bedeemed given.”

3.                                      Thefifth sentence of Section 24 is hereby deleted and replaced with the following:

“Tenant may assign this Lease to a successor to Tenantby merger, consolidation or the purchase of substantially all of Tenant’sassets, or assign this Lease or sublet all or a portion of the Premises to anAffiliate (defined below), without the consent of Landlord, provided that allof the following conditions are satisfied (a “**PermittedTransfer**”):  (a) Tenant mustnot be in Default; (b) Tenant must give Landlord written notice at least 15Business Days before such Transfer; and (c) if such Transfer will result from amerger or consolidation of Tenant with another entity, then the CreditRequirement (defined below) must be satisfied. Tenant’s notice to Landlord shall include information and documentationevidencing the Permitted Transfer and showing that each of the above conditionshas been satisfied.  If requested byLandlord, Tenant’s successor shall sign a commercially reasonable form ofassumption agreement.  “**Affiliate**” shall mean an entity controlled by, controllingor under common control with Tenant.  The“Credit Requirement” shall be deemed satisfied if, as of the date immediatelypreceding the date of the Transfer, the financial strength of the entity withwhich Tenant is to merge or consolidate is not less than that of Tenant, asdetermined (x) based on credit ratings of such entity and Tenant by both Moody’sand Standard & Poor’s (or by either such agency alone, if applicableratings by the other agency do not exist), or (y) if such credit ratings do notexist, then in accordance with Moody’s KMV RiskCalc (i.e., the on-line softwaretool offered by Moody’s for analyzing credit risk) based on CFO-certifiedfinancial statements for such entity and Tenant covering their last two fiscalyears ending before the Transfer.”

4.                                      Theproviso in the first sentence of the second full paragraph of Section 24 of theLease is hereby deleted.

Q.                                    [IntentionallyOmitted]

R.                                     **Recording**. At Landlord’s option, Tenant shall execute forrecording a short form memorandum of lease reflecting the deletion of Section35 of the Lease.

S.                                      **Tenant’s Remedy.**  Thelast clause of the first sentence of Section 45 of the Lease is hereby amendedto replace “Landlord nor its partners” with “Landlord nor its trustees,members, principals, beneficiaries, partners, officers, directors, employees,lenders or agents.”

T.                                     **Payment of Property Expenses.**

1.                                      Notwithstandinganything in****Section 47 of the Lease to thecontrary, Landlord (a) with respect to any portion of the Premises located in ain a Multi-Tenant Building shall, and (b) with respect to any portion of thePremises located in a Building that is fully leased by Tenant may, at Landlord’soption, include amounts representing a reasonable estimate of the averagemonthly cost (determined by dividing the estimated total annual cost of eachsuch category by 12) of Real Property Taxes and

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assessments and insurancepremiums payable by Tenant in Landlord’s estimated average expenditures ofProperty Expenses, for payment on a monthly basis in the manner provided inSection 47 with respect to Property Expenses, in lieu of billing Tenantseparately for such items.

2.                                      Thefollowing is added to the end of the first paragraph of Section 47: “, providedthat such audit is commenced within 12 months following Tenant’s receipt ofLandlord’s reconciliation for the previous 12-month period and thereafterdiligently prosecuted to completion.”

3.                                      Section47 is hereby amended to reflect that Landlord’s annual reconciliation is preparedon a calendar year basis, with Landlord’s annual reconciliation statementdelivered to Tenant as soon as practicable following the end of each calendaryear.  Landlord shall use reasonableefforts to furnish the reconciliation statement on or before June 1 of thecalendar year immediately following the calendar year to which the statementapplies.

U.                                    **Remediation Program. **Withrespect to Section 48.B(i), clause (1),****Tenant herebyacknowledges and agrees that there are no “additional Hazardous Materials discoveredon the Premises by Tenant during any baseline testing of the Premises conductedin connection with the execution of [the Original Lease]” and that theapplicable parenthetical is therefore of no force and effect.

V.                                     **Right to Cure Landlord Defaults.**  Section 49 of the Lease shall not apply toany space located in a Multi-Tenant Building. The last sentence of Section 49 is hereby modified to provide thatLandlord’s obligation to pay interest on costs incurred byTenant shall commence upon the 10th day following Tenant’s giving writtennotice to Landlord together with reasonable supporting documentation of costsincurred by Tenant.

W.                                **Parking.**  Effective asof the Must-Take Effective Date, Tenant shall be entitled to an additional 92non-reserved spaces in the parking facility**,**for a totalof 270 spaces.  In addition, Tenant shallbe entitled to convert up to 4 of Tenant’s spaces into reserved spaces, inlocations reasonably determined by Landlord in the vicinity of the InitialPremises, at no charge during the Extended Term.  Tenant shall be entitled to additionalnon-reserved spaces in connection with Tenant’s leasing of any of the OfferingSpace at a ratio of 3.3 spaces per 1,000 rentable square feet of Offering Spaceleased by Tenant.

X.                                    **Environmental Disclosure.** Tenant acknowledges that (i) the soil and/or groundwater underlying theFoothill Research Center contain hazardous substances, including volatileorganic compounds, (ii) the Project is subject to certain orders by theCalifornia Regional Water Quality Control Board, San Francisco Bay Region (the “**Board**”), and (iii) Tenant has reviewed, to its satisfaction,an environmental site assessment report dated August 1993, prepared by EMCOMAssociates and entitled “Phase I Environmental Site Assessment”, receipt ofwhich is hereby acknowledged by Tenant, together with all publicly availableinformation regarding the environmental condition of such soil landgroundwater, and that Landlord has provided to Tenant an opportunity to reviewall other materials in Landlord’s possession regarding the environmentalcondition of the Foothill Research Center. Tenant acknowledges that the land underlying the Premises, as the samemay be expanded, may be subject to various covenants and restrictions may  imposed by the Board, which covenants andrestrictions may impose certain limitation on the use of the Premises, andTenant covenants to comply with all of the terms and conditions of any suchcovenants and restrictions.  ThisParagraph X is not intended to modify Landlord’s and Tenant’s rights andobligations set forth in Section 48 of the Lease.

Y.                                     **Separation of Lease Document.**  Landlordreserves the right, in Landlord’s sole discretion, to subdivide the legalparcel containing the 4001 Building, the 4005 Building and the 4009 Buildinginto one or more separate legal parcels, and to separately sell or finance anyone or more of the four Buildings. In the event of a subdivision after the dateof this Fourth Amendment, or in the event that Landlord elects to market forsale or to finance one or more of the Buildings separately from other Buildingsin the Complex, then Tenant, upon written

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request from Landlord,shall enter into new and separate lease agreements applicable to the portionsof the Premises located in the applicable Building(s) on the same terms andconditions set forth in the Lease, as amended hereby, with appropriatemodifications to reflect the square footage of each respective portion of thePremises and the location of each respective portion of the Premises covered bysuch lease, conditioned upon Landlord paying to Tenant an amount equal to thereasonable attorney’s fees incurred by Tenant in connection with review andnegotiation of such documentation and the reasonable costs of having the Letterof Credit re-issued so that it is allocated appropriately; provided thatLandlord shall not be responsible for any attorneys’ fees incurred by Tenant inconnection with preparation of an Arbitration Notice or in connection with anyarbitration procedure. The draft lease(s) shall allocate any then remainingcash security deposit and/or Letter of Credit between the resulting leases on apro rata basis based on relative square footage. Tenant’s rights andobligations under the Lease with respect to the Containment Facility shall beincluded only in the lease document governing the Initial Premises. Theseparate leases shall be prepared and executed in accordance with the followingprocedure:

1.                                      Landlordshall deliver initial draft leases to Tenant, and Tenant shall review andprovide any reasonable comments thereon pertaining to whether the draft leasesare Accurate (as defined below) within 30 days following Tenant’s receipt ofsuch drafts by Landlord. Landlord shall promptly revise the draft leases toaccommodate such comments (the “**Revised Drafts**”).  Provided that the Revised Drafts areconsistent with the terms and provisions of the Lease, as then amended to date,and this Paragraph 1 and do not significantly impair any of Tenant’s rightsunder the Lease with respect to the portion of the Premises in the applicableBuildings (for purposes of this Section Y, are “**Accurate**”),Tenant shall execute the Revised Drafts no later than 15 days followingLandlord’s delivery thereof to Tenant (the “**RevisedDraft****Execution Date**”).  If Tenant reasonably and in good faithdetermines that the Revised Drafts are not fully Accurate, Tenant may deliver anotice (“**Negotiation Notice”**) to Landlord nolater than the Revised Draft Execution Date, which Negotiation Notice shall setforth in reasonable detail the provisions of the Revised Drafts that Tenantbelieves are not Accurate.  If Tenantfails to deliver a Negotiation Notice that meets the requirements of thisParagraph 1 by the Revised Draft Execution Date, Tenant shall be deemed to haveaccepted the Revised Drafts as Accurate. Promptly following a Negotiation Notice, Landlord and Tenant shallnegotiate reasonably and in good faith to resolve any specific disputes setforth in Tenant’s Negotiation Notice, and Landlord shall promptly revise theRevised Drafts to reflect any such agreements (“**NegotiatedDrafts**”).

2.                                      Providedthat the Negotiated Drafts are Accurate, Tenant shall execute the NegotiatedDrafts no later than 15 days following Landlord’s delivery thereof to Tenant(the “**Negotiated Draft****ExecutionDate**”).  If Tenant reasonablyand in good faith determines that the Negotiated Drafts are not fully Accurate,Tenant may deliver a notice (“**Lease Arbitration Notice”**)to Landlord no later than the Negotiated Draft Execution Date, which LeaseArbitration Notice shall set forth in reasonable detail the provisions of theNegotiated Drafts that Tenant believes are not Accurate.  If Tenant fails to deliver a LeaseArbitration Notice that meets the requirements of this Paragraph 2 by theNegotiated Draft Execution Date, Tenant shall be deemed to have accepted theNegotiated Drafts as Accurate.  Uponreceipt of a Lease Arbitration Notice, Landlord shall submit a response toTenant describing Landlord’s position on each item identified in Tenant’s LeaseArbitration Notice (“**Landlord’s Response**”).

3.                                      Within15 days following a Lease Arbitration Notice, Landlord and Tenant each shallselect as an arbitrator an attorney licensed in California with at least 10years experience in commercial leasing practice in the Santa Clara County area,provided that such attorney and any firm with which such attorney is associateddoes not then represent either party and has not represented either party in atleast 5 years (a “**Qualified Arbitrator**”),and the parties shall negotiate reasonably and in good faith to mutually agreeon a third Qualified Arbitrator. If Landlord and Tenant are unable to agreewithin such 15 day period on a third Qualified Arbitrator (or if either

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party fails to timelyselect its own Qualified Arbitrator), then the Qualified Arbitrator(s)previously selected shall select a third (or second and third, if one partyfailed to select a Qualified Arbitrator) to complete the arbitration panel (the“**Panel**”) of three (3) QualifiedArbitrators.

4.                                      Promptlyfollowing selection of the Panel, the Panel shall review the Lease, as thenamended to date, the Negotiated Drafts, Tenant’s Arbitration Notice andLandlord’s Response. The Panel shall not have the power to order furtherdiscovery.  If the entire Paneldetermines that it would be helpful to meet with the parties to discuss theirpositions on the issues, upon reasonable notice the parties shall makethemselves available at the time requested by the Panel or shall forfeit theright to so appear.  Within 45 days afterselection, the Panel shall issue a written opinion on each item set forth inTenant’s Lease Arbitration Notice, which opinion shall approve Tenant’sproposed language as Accurate, approve Landlord’s proposed language asAccurate, or provide alternate language approved by the Panel as Accurate, foreach such issue. If the Panel does not unanimously agree on any particularitem, the majority of the Panel members shall prevail. The decisions of thePanel shall be final and binding on both parties and may be entered as judgmenton the issue in any court having jurisdiction over such dispute.

5.                                      Followingthe Panel’s decision, Landlord shall promptly incorporate the Panel’sdeterminations into the Negotiated Drafts and circulate “**Final Drafts**”to Tenant for execution.  Provided thatthe Final Drafts accurately incorporate the Panel’s decisions, such FinalDrafts shall be deemed Accurate and Tenant shall execute such Final Draftswithin 10 days following receipt thereof. Landlord and Tenant may refer any disputes over whether the Final Draftsaccurately reflect the Panel’s decision to the Panel for a prompt determination(which shall be made by majority of the Panel if the Panel is not unanimous).

6.                                      Landlordand Tenant shall each be responsible for fifty percent (50%) of the costs ofthe arbitration, including the fees of the Qualified Arbitrators.  Each party shall pay its own attorneys’ feesin connection with Tenant’s Lease Arbitration Notice, Landlord’s Response andthe arbitration procedure.

7.                                      Tenant’sfailure to execute one or more leases that are deemed to be Accurate pursuantto the foregoing procedures within the time periods set forth therein shall besubject to a cure period of 10 days following written notice from Landlord. IfTenant fails to cure its noncompliance with this provision within such 10 daycure period, such failure shall be an incurable default under the Lease,without any further notice or cure period, and Tenant shall be liable for anyand all damages that Landlord may suffer as a result of Tenant’s failure.

Z.                                     **Stanford Consent**.   The effectiveness of thisFourth Amendment and Landlord’s and Tenant’s rights and obligations hereunderare conditioned upon the receipt of Stanford’s consent to this Fourth Amendmenton terms and conditions acceptable to the parties hereto and by Stanford and,if required by Stanford, the execution of a nondisturbance and recognitionagreement between Stanford and Tenant. If Landlord and Tenant have not obtainedsuch consent by the date which is sixty (60) days after the mutual executionand delivery of this Fourth Amendment by the parties, either party mayterminate this Fourth Amendment by written notice to the other party, effectiveas of the date of receipt of such notice, provided that such notice is receivedby the other party prior to Landlord and Tenant obtaining such consent.  Landlord shall have no obligation to disburseany portion of any allowance provided for in this Fourth Amendment until therequired consent and agreement have been obtained.

X.**                                    Miscellaneous.**

A.                                   This Fourth Amendment and **Exhibits A**through **E** attached hereto, which are herebyincorporated by reference, set forth the entire agreement between the partieswith respect to the matters set forth herein. There have been no additional oral or written representations oragreements.  Under no circumstances shall

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Tenant be entitled to any Rentabatement, improvement allowance, leasehold improvements, or other work to thePremises, or any similar economic incentives that may have been provided Tenantin connection with entering into the Lease, unless specifically set forth inthis Fourth Amendment.

B.                                     Except as herein modified or amended, theprovisions, conditions and terms of the Lease shall remain unchanged and infull force and effect.

C.                                     In the case of any inconsistency between theprovisions of the Lease and this Fourth Amendment, the provisions of thisFourth Amendment shall govern and control.

D.                                    Submission of this Fourth Amendment by Landlordis not an offer to enter into this Fourth Amendment but rather is asolicitation for such an offer by Tenant. Landlord shall not be bound by this Fourth Amendment until Landlord hasexecuted and delivered the same to Tenant.

E.                                      The capitalized terms used in this Fourth Amendmentshall have the same definitions as set forth in the Lease to the extent thatsuch capitalized terms are defined therein and not redefined in this FourthAmendment.

F.                                      Tenant hereby represents to Landlord that Tenanthas dealt with no broker in connection with this Fourth Amendment other thanCRESA Partners (“**Tenant’s Broker**”).  Tenant agrees to indemnify and hold Landlord,its trustees, members, principals, beneficiaries, partners, officers,directors, employees, mortgagee(s) and agents, and the respective principalsand members of any such agents harmless from all claims of any brokers otherthan Tenant’s Broker claiming to have represented Tenant in connection withthis Fourth Amendment, and from all claims of Tenant’s Broker for a commissionin connection with this transaction other than with respect to the Must-TakeSpace, as provided below.  Landlordagrees to pay a commission to Tenant’s Broker pursuant to the terms of aseparate agreement.  Landlord agrees toindemnify and hold Tenant, its trustees, members, principals, beneficiaries,partners, officers, directors, employees, and agents, and the respectiveprincipals and members of any such agents harmless from all claims of anybrokers claiming to have represented Landlord in connection with this FourthAmendment.

Equity Office PropertiesManagement Corp. (“**EOPMC**”) is anaffiliate of Landlord and represents only the Landlord in thistransaction.  Any assistance  rendered by  any agent or employee of EOPMCin connection with this Fourth Amendment or any subsequent amendment ormodification hereto has been or will be  made  as  an  accommodation to Tenant solely in furtheranceof consummating  the  transaction on behalf of Landlord, and not as agent for Tenant.

G.                                     Each party hereto represents that each signatoryof this Fourth Amendment signing on its behalf has the authority to execute anddeliver the same on behalf of the party hereto for which such signatory isacting.

H.                                    Tenant agrees that neither Tenant nor its agentsor any other parties acting on behalf of Tenant shall disclose any matters setforth in this Fourth Amendment or disseminate or distribute any informationconcerning the terms, details or conditions hereof to any person, firm orentity without obtaining the express written consent of Landlord or as requiredby law.

**[SIGNATURES ARE ON FOLLOWINGPAGE]**

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**IN WITNESS WHEREOF**, Landlord and Tenant have duly executed thisFourth Amendment as of the day and year first above written.
|        | ** ** | **LANDLORD:**                                                                        |
|--------|------------|--------------------------------------------------------------------------------------|
|   |       |                                                                                 |
|   | ** ** | **CA-FOOTHILL RESEARCH CENTER LIMITED  PARTNERSHIP, a Delaware limited partnership** |
|   | ** ** | ** **                                                                           |
|   |       | By:                                                                                  | EOM GP, L.L.C., a Delaware limited liability  company, its general partner |
|   |       |                                                                                 |   |
|   |       |                                                                                 | By: | Equity Office Management, L.L.C., a Delaware limited  liability company, its non-member manager |
|   |       |                                                                                 |   |   |
|   |       |                                                                                 | By: | /s/ KENNETH J. CHURICH |   |
|   |       |                                                                                 |   |   |   |
|   |       |                                                                                 | Name: | Kenneth J. Churich |   |
|   |       |                                                                                 |   |   |   |
|   |       |                                                                                 | Title: | Vice President Leasing |   |
|   | ** ** | ** **                                                                           |
|   | ** ** | ** **                                                                           |
|   |       | **TENANT:**                                                                          |
|   |       | ** **                                                                           |
|   |       | ** **                                                                           |
|   | ** ** | **AFFYMAX, INC., a Delaware corporation**                                            |
|   |       |                                                                                 |
|   |       | By:                                                                                  | /s/ ARLENE M. MORRIS |   |
|   |       |                                                                                 |   |   |
|   |       | Name:                                                                                | Arlene M. Morris |   |
|   |       |                                                                                 |   |   |
|   |       | Title:                                                                               | President & CEO |   |
|   |       |                                                                                 |   |
|   |       |                                                                                 |   |
|   | ** ** | **FEIN:**                                                                            | ** ** | ** ** |
|        |            |                                                                                      |  |  |  |  |  |  |

 

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**EXHIBIT A**

**OUTLINE AND LOCATION OF MUST-TAKE SPACE**

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**EXHIBIT B**

**MUST-TAKEWORK LETTER**

Asused in this Work Letter, the “**Premises**” shallbe deemed to mean the Must-Take Space, as defined in the Fourth Amendment towhich this Work Letter is attached.

I.**                                         Alterationsand Allowance.**

A.                                   Tenant,following the Must-Take Effective Date (as defined in the Fourth Amendment),shall have the right to perform alterations and improvements in the Premises(the “**Must-Take Alterations**”).  Notwithstanding the foregoing, Tenant and itscontractors shall not have the right to perform Must-Take Alterations in thePremises unless and until Tenant has complied with all of the terms andconditions of Section 12 of the Lease, including, without limitation, approvalby Landlord of the final plans for the Must-Take Alterations and thecontractors to be retained by Tenant to perform such Must-Take Alterations.Tenant shall be responsible for all elements of the design of Tenant’s plans(including, without limitation, compliance with law, functionality of design,the structural integrity of the design, the configuration of the premises andthe placement of Tenant’s furniture, appliances and equipment), and Landlord’sapproval of Tenant’s plans shall in no event relieve Tenant of theresponsibility for such design.  Landlord’sapproval of the contractors to perform the Must-Take Alterations shall not beunreasonably withheld.  The parties agreethat Landlord’s approval of the general contractor to perform the Must-TakeAlterations shall not be considered to be unreasonably withheld if any suchgeneral contractor (i) does not have trade references reasonablyacceptable to Landlord, (ii) does not maintain insurance as requiredpursuant to the terms of this Lease, (iii) does not have the ability to bebonded for the work in an amount of no less than 150% of the total estimatedcost of the Must-Take Alterations, (iv) does not provide current financialstatements reasonably acceptable to Landlord, or (v) is not licensed as acontractor in the state/municipality in which the Premises is located.  Tenant acknowledges the foregoing is notintended to be an exclusive list of the reasons why Landlord may reasonablywithhold its consent to a general contractor.

B.**                                    **ProvidedTenant is not in default, Landlord agrees tocontribute the sum of **$336,930.00**(the “**Must-Take Allowance**”) toward the costof performing the Must-Take Alterations in preparation of Tenant’s occupancy ofthe Premises.  The Must-Take Allowancemay only be used for the cost of preparing design and construction documentsand mechanical and electrical plans for the Must-Take Alterations and for******hard costs in connection with theMust-Take Alterations.  The Must-TakeAllowance, less a 10% retainage (which retainage shall be payable as part ofthe final draw), shall be paid to Tenant or, at Landlord’s option, to the orderof the general contractor that performs the Must-Take Alterations, in periodicdisbursements within 30 days after receipt of the following documentation:(i) an application for payment and sworn statement of contractorsubstantially in the form of AIA Document G-702 covering all work for whichdisbursement is to be made to a date specified therein; (ii) acertification from an AIA architect substantially in the form of the Architect’sCertificate for Payment which is located on AIA Document G702, Application andCertificate of Payment; (iii) Contractor’s, subcontractor’s and materialsupplier’s waivers of liens which shall cover all Must-Take Alterations forwhich disbursement is being requested and all other statements and formsrequired for compliance with the mechanics’ lien laws of the state in which thePremises is located, together with all such invoices, contracts, or other supportingdata as Landlord or Landlord’s mortgagee, if any, may reasonably require;(iv) a cost breakdown for each trade or subcontractor performing theMust-Take Alterations; (v) plans and specifications for the Must-TakeAlterations, together with a certificate from an AIA architect that such plansand specifications comply in all material respects with all laws affecting the4015 Building, the Complex and the Premises; (vi) copies of allconstruction contracts for the Must-Take Alterations, together with copies ofall change orders, if any; and (vii) a request to disburse from Tenantcontaining an approval by Tenant of the work done and a good faith estimate ofthe cost to complete the Must-Take Alterations. Upon completion of the Must-Take Alterations, and prior to finaldisbursement of the Must-Take Allowance, Tenant shall furnish Landlordwith:  (1) general contractor andarchitect’s completion affidavits, (2) full and final waivers of lien,(3) receipted bills covering all labor and materials expended and used,(4) as-built plans of the Must-

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Take Alterations, and (5) the certificationof Tenant and its architect that the Must-Take Alterations have been installedin a good and workmanlike manner in accordance with the approved plans, and inaccordance with applicable laws, codes and ordinances.  In no event shall Landlord be required todisburse the Must-Take Allowance more than one time per month.  If the Must-Take Alterations exceed theMust-Take Allowance, Tenant shall be entitled to the Must-Take Allowance inaccordance with the terms hereof, but each individual disbursement of theMust-Take Allowance shall be disbursed in the proportion that the Must-TakeAllowance bears to the total cost for the Must-Take Alterations, less the 10%retainage referenced above. Notwithstanding anything herein to the contrary, Landlord shall not beobligated to disburse any portion of the Must-Take Allowance during thecontinuance of an uncured default under the Lease, and Landlord’s obligation todisburse shall only resume when and if such default is cured.

C.                                     In no event shall the Must-Take Allowance be usedfor the purchase of equipment, furniture or other items of personal property ofTenant.  If Tenant does not submit arequest for payment of the entire Must-Take Allowance to Landlord in accordancewith the provisions contained in this Work Letter by December 31, 2011, anyunused amount shall accrue to the sole benefit of Landlord, it being understoodthat Tenant shall not be entitled to any credit, abatement or other concessionin connection therewith. Tenant shall be responsible for all applicable statesales or use taxes, if any, payable in connection with the Must-TakeAlterations and/or Must-Take Allowance.** **Landlord shall be entitled todeduct from the Must-Take Allowance a construction management fee for Landlord’soversight of the Must-Take Alterations in an amount equal to 3% of the totalcost of the Must-Take Alterations.

D.                                    Tenant agrees to accept the Premises in its “as-is”condition and configuration, it being agreed that Landlord shall not berequired to perform any work or, except as provided above with respect to theAllowance, incur any costs in connection with the construction or demolition ofany improvements in the Premises.

E.                                      This Work Letter shall not be deemed applicable toany additional space added to the Premises at any time or from time to time,whether by any options under the Lease or otherwise, or to any portion of theInitial Premises or any additions to the Premises in the event of a renewal orextension of the Extended Term of the Lease, whether by any options under theLease or otherwise, unless expressly so provided in the Lease or any amendmentor supplement to the Lease.

F.                                      Section 13 of the Work Letter attached as ExhibitC to the Original Lease is incorporated herein by this reference with respectto the Must-Take Alterations.  TheMust-Take Alterations shall be “Tenant Improvements” under the Lease, includingfor purposes of Section 12.B and **Exhibit E**ofthe Original Lease.  No other provisionsof the original Work Letter shall apply to the Must-Take Alterations, unlessspecifically set forth in this Paragraph F.

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**EXHIBIT C**

**INITIALPREMISES WORK LETTER**

Asused in this Work Letter, the “**Premises**” shallbe deemed to mean the Initial Premises, as defined in the Fourth Amendment towhich this Work Letter is attached.

I.**                                         Alterationsand Allowance.**

A.                                   Tenant,following the full execution of the Fourth Amendment and Landlord’s receipt ofthe Letter of Credit required thereby, shall have the right to performalterations and improvements in the Premises (the “**InitialPremises Alterations**”). Notwithstanding the foregoing, Tenant and its contractors shall not havethe right to perform Initial Premises Alterations in the Premises unless anduntil Tenant has complied with all of the terms and conditions of Section 12 ofthe Lease, including, without limitation, approval by Landlord of the finalplans for the Initial Premises Alterations and the contractors to be retainedby Tenant to perform such Initial Premises Alterations. Tenant shall beresponsible for all elements of the design of Tenant’s plans (including,without limitation, compliance with law, functionality of design, thestructural integrity of the design, the configuration of the premises and theplacement of Tenant’s furniture, appliances and equipment), and Landlord’sapproval of Tenant’s plans shall in no event relieve Tenant of theresponsibility for such design.  Landlord’sapproval of the contractors to perform the Initial Premises Alterations shallnot be unreasonably withheld. The parties agree that Landlord’s approval of thegeneral contractor to perform the Initial Premises Alterations shall not beconsidered to be unreasonably withheld if any such general contractor(i) does not have trade references reasonably acceptable to Landlord,(ii) does not maintain insurance as required pursuant to the terms of thisLease, (iii) does not have the ability to be bonded for the work in anamount of no less than 150% of the total estimated cost of the Initial PremisesAlterations, (iv) does not provide current financial statements reasonablyacceptable to Landlord, or (v) is not licensed as a contractor in thestate/municipality in which the Premises is located.  Tenant acknowledges the foregoing is notintended to be an exclusive list of the reasons why Landlord may reasonablywithhold its consent to a general contractor.

B.**                                    **ProvidedTenant is not in default, Landlord agrees tocontribute the sum of **$1,614,900.00**(the “**Initial Premises Allowance**”) toward thecost of performing the Initial Premises Alterations. The Initial PremisesAllowance may only be used for the cost of preparing design and constructiondocuments and mechanical and electrical plans for the Initial PremisesAlterations and for******hard costs in connectionwith the Initial Premises Alterations. The Initial Premises Allowance, less a 10% retainage (which retainageshall be payable as part of the final draw), shall be paid to Tenant or, atLandlord’s option, to the order of the general contractor that performs theInitial Premises Alterations, in periodic disbursements within 30 days afterreceipt of the following documentation: (i) an application for payment andsworn statement of contractor substantially in the form of AIA Document G-702covering all work for which disbursement is to be made to a date specifiedtherein; (ii) a certification from an AIA architect substantially in theform of the Architect’s Certificate for Payment which is located on AIADocument G702, Application and Certificate of Payment; (iii) Contractor’s,subcontractor’s and material supplier’s waivers of liens which shall cover allInitial Premises Alterations for which disbursement is being requested and allother statements and forms required for compliance with the mechanics’ lienlaws of the state in which the Premises is located, together with all suchinvoices, contracts, or other supporting data as Landlord or Landlord’smortgagee, if any, may reasonably require; (iv) a cost breakdown for eachtrade or subcontractor performing the Initial Premises Alterations;(v) plans and specifications for the Initial Premises Alterations,together with a certificate from an AIA architect that such plans andspecifications comply in all material respects with all laws affecting the 4001Miranda Building, the Complex and the Premises; (vi) copies of allconstruction contracts for the Initial Premises Alterations, together withcopies of all change orders, if any; and (vii) a request to disburse fromTenant containing an approval by Tenant of the work done and a good faithestimate of the cost to complete the Initial Premises Alterations.  Upon completion of the Initial PremisesAlterations, and prior to final disbursement of the Initial Premises Allowance,Tenant shall furnish Landlord with: (1) general contractor and architect’s completion affidavits,(2) full and final waivers of lien,

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(3) receipted bills covering all labor andmaterials expended and used, (4) as-built plans of the Initial PremisesAlterations, and (5) the certification of Tenant and its architect thatthe Initial Premises Alterations have been installed in a good and workmanlikemanner in accordance with the approved plans, and in accordance with applicablelaws, codes and ordinances.  In no eventshall Landlord be required to disburse the Initial Premises Allowance more thanone time per month.  If the InitialPremises Alterations exceed the Allowance, Tenant shall be entitled to theInitial Premises Allowance in accordance with the terms hereof, but eachindividual disbursement of the Initial Premises Allowance shall be disbursed inthe proportion that the Initial Premises Allowance bears to the total cost forthe Initial Premises Alterations, less the 10% retainage referenced above.Notwithstanding anything herein to the contrary, Landlord shall not beobligated to disburse any portion of the Initial Premises Allowance during thecontinuance of an uncured default under the Lease, and Landlord’s obligation todisburse shall only resume when and if such default is cured.

C.                                     Landlord and Tenant acknowledge that Tenant mayperform improvements in all or any portion of the Must-Take Space during Tenant’speriod of possession thereof pursuant to the Tibco Sublease (the “**Sublease Alterations**”), and that any such SubleaseAlterations shall be subject to the terms of the Existing Lease, the TibcoSublease and the Consent (all as defined in Recital B of the FourthAmendment).  Provided that Tenantcomplies with all applicable requirements in connection therewith, Landlordhereby agrees that Tenant may apply up to **$250,000.00** ofthe Initial Premises Allowance towards the cost of the SubleaseAlterations.  Such portion of theAllowance shall be disbursed in the same manner and subject to the sameconditions as govern disbursements in connection with the Initial PremisesAlterations, as set forth in Paragraph B above and Paragraph D below.

D.                                    In no event shall the Initial Premises Allowancebe used for the purchase of equipment, furniture or other items of personalproperty of Tenant.  If Tenant does notsubmit a request for payment of the entire Initial Premises Allowance toLandlord in accordance with the provisions contained in this Work Letter byDecember 31, 2010, any unused amount shall accrue to the sole benefit ofLandlord, it being understood that Tenant shall not be entitled to any credit,abatement or other concession in connection therewith. Tenant shall beresponsible for all applicable state sales or use taxes, if any, payable inconnection with the Initial Premises Alterations and/or Initial PremisesAllowance.** **Landlordshall be entitled to deduct from the Initial Premises Allowance a constructionmanagement fee for Landlord’s oversight of the Initial Premises Alterations inan amount equal to 3% of the total cost of the Initial Premises Alterations.

E.                                      Tenant agrees to accept the Premises in its “as-is”condition and configuration for the Extended Term, it being agreed thatLandlord shall not be required to perform any work or, except as provided abovewith respect to the Initial Premises Allowance, incur any costs in connectionwith the construction or demolition of any improvements in the Premises.

F.                                      This Work Letter shall not be deemed applicable toany additional space added to the Premises at any time or from time to time,whether by any options under the Lease or otherwise, or to any portion of theMust-Take Space (except as provided in Paragraph C above)****orany additions to the Premises in the event of a renewal or extension of theExtended Term of the Lease, whether by any options under the Lease orotherwise, unless expressly so provided in the Lease or any amendment orsupplement to the Lease.

G.                                     Section 13 of the Work Letter attached as ExhibitC to the Original Lease is incorporated herein by this reference with respectto the Initial Premises Alterations. The Initial Premises Alterations shall be “TenantImprovements” under the Lease, including for purposes of Section 12.B and **Exhibit E**of the Original Lease.  No other provisions of the original WorkLetter shall apply to the Initial Premises Alterations, unless specifically setforth in this Paragraph G.

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**EXHIBIT D**

**FORM OFLETTER OF CREDIT**

[Name of FinancialInstitution]

Irrevocable Standby

Letter of Credit

No.                                           

Issuance Date:                          

Expiration Date:                       

Applicant: Affymax, Inc.

Beneficiary

CA-Foothill Research Center Limited Partnership

c/o Equity Office

1740 Technology Drive, Suite 150

San Jose, California  95110

Attention: FoothillProperty Manager

Ladies/Gentlemen:

We herebyestablish our Irrevocable Standby Letter of Credit in your favor for theaccount of the above referenced Applicant in the amount of                              U.S. Dollars ($                            )available for payment at sight by your draft drawn on us when accompanied bythe following documents:

1.                                       Anoriginal copy  of this IrrevocableStandby Letter of Credit.

2.                                       Beneficiary’sdated statement purportedly signed by an authorized signatory or agent reading:“This draw in the amount of                         U.S. Dollars ($                 )under your Irrevocable Standby Letter of Credit No.                                 represents funds that we are entitled to draw pursuant to the terms of thatcertain lease by and between CA-Foothill Research Center Limited Partnership, aDelaware limited partnership, as landlord, and Affymax, Inc., a Delawarecorporation (as successor in interest to Affymax Research Institute, aCalifornia corporation), as tenant, and/or any amendment to the lease or anyother agreement between such parties related to the lease.”

It is a conditionof this Irrevocable Standby Letter of Credit that it will be consideredautomatically renewed for a one year period upon the expiration date set forthabove and upon each anniversary of such date, unless at least 60 days prior tosuch expiration date or applicable anniversary thereof, we notify you inwriting, by certified mail return receipt requested or by recognized overnightcourier service, that we elect not to so renew this Irrevocable Standby Letterof Credit.  A copy of any such noticeshall also be sent, in the same manner, to: Equity Office Properties Trust, 2 North Riverside Plaza, Suite 2100,Chicago, Illinois 60606, Attention: Treasury Department.  In addition to the foregoing, we understandand agree that you shall be entitled to draw upon this Irrevocable StandbyLetter of Credit in accordance with 1 and 2 above in the event that we electnot to renew this Irrevocable Standby Letter of Credit and, in addition, youprovide us with a dated statement purportedly signed by an authorized signatoryor agent of Beneficiary stating that the Applicant has failed to provide youwith an acceptable substitute irrevocable standby letter of credit inaccordance with the terms of the above referenced lease.  We further acknowledge and agree that:  (a) upon receipt of the documentationrequired herein, we will honor your draws against this Irrevocable StandbyLetter of Credit without inquiry into the accuracy of Beneficiary’s signedstatement and regardless of whether Applicant disputes the content of suchstatement; (b) this Irrevocable Standby Letter of Credit shall permitpartial draws and, in the event you elect to draw upon less than the fullstated amount hereof, the stated amount of this Irrevocable Standby Letter ofCredit shall be automatically reduced by the amount of such partial draw; and(c) you shall be entitled to transfer your interest in this Irrevocable StandbyLetter of Credit from time to time and more than one time without our approvaland without charge.  In the event of atransfer, we reserve the right to require reasonable evidence of such transferas a condition to any draw hereunder.

This IrrevocableStandby Letter of Credit is subject to the Uniform Customs and Practice

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for Documentary Credits(1993 revision) ICC Publication No. 500.

We hereby engagewith you to honor drafts and documents drawn under and in compliance with theterms of this Irrevocable Standby Letter of Credit.

All communicationsto us with respect to this Irrevocable Standby Letter of Credit must beaddressed to our office located at                                                                                         to the attention of                                                                .
|        | Very truly yours, |   |
|--------|-------------------|--------|
|   |              |   |
|   |              |   |
|   |              |   |
|   | [name]            |   |
|   |              |   |
|   | [title}           |   |

 

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**EXHIBIT E-1**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4005 Miranda, Suite 100**

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**EXHIBIT E-2**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4005 Miranda, Suite 150**

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**EXHIBIT E-3**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4005 Miranda, Suite 160**

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**EXHIBIT E-4**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4005 Miranda, Suite 175**

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**EXHIBIT E-5**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4009 Miranda, Suite 100**

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**EXHIBIT E-6**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4009 Miranda, Suite 200**

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**EXHIBIT E-7**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4009 Miranda, Suite 225**

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**EXHIBIT E-8**

**OUTLINE AND LOCATION OF OFFERING SPACE**

**4009 Miranda, Suite 250**

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